WorldWideScience

Sample records for dynamic energy budget

  1. Dynamic energy budget approaches for modelling organismal ageing.

    Science.gov (United States)

    van Leeuwen, Ingeborg M M; Vera, Julio; Wolkenhauer, Olaf

    2010-11-12

    Ageing is a complex multifactorial process involving a progressive physiological decline that, ultimately, leads to the death of an organism. It involves multiple changes in many components that play fundamental roles under healthy and pathological conditions. Simultaneously, every organism undergoes accumulative 'wear and tear' during its lifespan, which confounds the effects of the ageing process. The scenario is complicated even further by the presence of both age-dependent and age-independent competing causes of death. Various manipulations have been shown to interfere with the ageing process. Calorie restriction, for example, has been reported to increase the lifespan of a wide range of organisms, which suggests a strong relation between energy metabolism and ageing. Such a link is also supported within the main theories for ageing: the free radical hypothesis, for instance, links oxidative damage production directly to energy metabolism. The Dynamic Energy Budgets (DEB) theory, which characterizes the uptake and use of energy by living organisms, therefore constitutes a useful tool for gaining insight into the ageing process. Here we compare the existing DEB-based modelling approaches and, then, discuss how new biological evidence could be incorporated within a DEB framework.

  2. Integrating dynamic energy budget (DEB) theory with traditional bioenergetic models.

    Science.gov (United States)

    Nisbet, Roger M; Jusup, Marko; Klanjscek, Tin; Pecquerie, Laure

    2012-03-15

    Dynamic energy budget (DEB) theory offers a systematic, though abstract, way to describe how an organism acquires and uses energy and essential elements for physiological processes, in addition to how physiological performance is influenced by environmental variables such as food density and temperature. A 'standard' DEB model describes the performance (growth, development, reproduction, respiration, etc.) of all life stages of an animal (embryo to adult), and predicts both intraspecific and interspecific variation in physiological rates. This approach contrasts with a long tradition of more phenomenological and parameter-rich bioenergetic models that are used to make predictions from species-specific rate measurements. These less abstract models are widely used in fisheries studies; they are more readily interpretable than DEB models, but lack the generality of DEB models. We review the interconnections between the two approaches and present formulae relating the state variables and fluxes in the standard DEB model to measured bioenergetic rate processes. We illustrate this synthesis for two large fishes: Pacific bluefin tuna (Thunnus orientalis) and Pacific salmon (Oncorhynchus spp.). For each, we have a parameter-sparse, full-life-cycle DEB model that requires adding only a few species-specific features to the standard model. Both models allow powerful integration of knowledge derived from data restricted to certain life stages, processes and environments.

  3. Entrainment of cell division in phytoplankton with dynamic energy budgets

    Science.gov (United States)

    Muller, Erik B.; Ananthasubramaniam, Bharath; Klanjšček, Tin; Nisbet, Roger M.

    2011-11-01

    We explore the entrainment behavior of cell division in phytoplankton in the context of Dynamic Energy Budget (DEB) theory. In particular, we explore the range of DEB and environmental parameter values within which a cell divides at regular intervals in a periodic light environment with abundant nutrients and investigate the impact of parameter values on the phase of cell division. We consider three types of cells that differ in the evolution of surface area to volume ratio during the cell cycle: cells with a constant shape (isomorphs), cells with a constant surface area (V0-morphs) and cells with a constant surface area to volume ratio (V1-morphs), the latter being the default choice in studies on the population dynamics of unicellular organisms because of its desirable mathematical implications. Only in isomorphs and V0-morphs, however, cell division can be entrained to a periodic light. Regular cell division in V1 is purely coincidental, as it depends on exact choices for parameter values. We attribute this to the fact that V1-morphs lack the negative feedback of size on the dynamics of reserves in V0-morphs and isomorphs. Because entrained isomorphs and V0-morphs divide during the dark hours in our simulations, these two shapes can represent the division behavior of phytoplankton species that complete the cell cycle during the night, such as dinoflagellates and coccolithophores. A description of the division behavior of species completing the cell cycle during the day, such as silicon dependent diatoms and cyanobacteria, requires a more complex model than used in this paper. Furthermore, we explore the robustness of our findings by randomizing model parameters and introducing unevenness in biomass separation between daughter cells during cell division. We conclude that especially the entrainment in V0-morphs is relatively insensitive to perturbations.

  4. Validation of a Dynamic Energy Budget (DEB) model for the blue mussel

    NARCIS (Netherlands)

    Saraiva, S.; van der Meer, J.; Kooijman, S.A.L.M.; Witbaard, R.; Philippart, C.J.M.; Hippler, D.; Parker, R.

    2012-01-01

    A model for bivalve growth was developed and the results were tested against field observations. The model is based on the Dynamic Energy Budget (DEB) theory and includes an extension of the standard DEB model to cope with changing food quantity and quality. At 4 different locations in the North Sea

  5. Extrapolating toxic effects on individuals to the population level: the role of dynamic energy budgets

    NARCIS (Netherlands)

    Jager, T.; Klok, T.C.

    2010-01-01

    The interest of environmental management is in the long-term health of populations and ecosystems. However, toxicity is usually assessed in short-term experiments with individuals. Modelling based on dynamic energy budget (DEB) theory aids the extraction of mechanistic information from the data,

  6. Validation of a Dynamic Energy Budget (DEB) model for the blue mussel

    NARCIS (Netherlands)

    Saraiva, S.; van der Meer, J.; Kooijman, S.A.L.M.; Witbaard, R.; Philippart, C.J.M.; Hippler, D.; Parker, R.

    2012-01-01

    A model for bivalve growth was developed and the results were tested against field observations. The model is based on the Dynamic Energy Budget (DEB) theory and includes an extension of the standard DEB model to cope with changing food quantity and quality. At 4 different locations in the North Sea

  7. Growth of cockles (Cerastoderma edule) in the Oosterschelde described by a Dynamic Energy Budget model

    NARCIS (Netherlands)

    Wijsman, J.W.M.; Smaal, A.C.

    2011-01-01

    A Dynamic Energy Budget (DEB) model for cockles is presented and calibrated using detailed data on cockle growth and water quality in the Oosterschelde. Cockles in the intertidal areas of the Oosterschelde have an important function as a food source for wading birds and as such for the natural value

  8. Exploring the effects of temperature and resource limitation on mercury bioaccumulation in Fundulus heteroclitus using dynamic energy budget modeling

    Science.gov (United States)

    Dynamic energy budget (DEB) theory provides a generalizable and broadly applicable framework to connect sublethal toxic effects on individuals to changes in population survival and growth. To explore this approach, we conducted growth and bioaccumulation studies that contribute t...

  9. Dynamic-energy-budget-driven fruiting-body formation in myxobacteria

    Science.gov (United States)

    Hendrata, M.; Birnir, B.

    2010-06-01

    We develop an interacting particle model to simulate the life cycle of myxobacteria, which consists of two main stages—the swarming stage and the development (fruiting body formation) stage. As experiments have shown that the phase transition from swarming to development stage is triggered by starvation, we incorporate into the simulation a system of ordinary differential equations (ODEs) called the dynamic energy budget, which controls the uptake and use of energy by individuals. This inclusion successfully automates the phase transition in our simulation. Only one parameter, namely, the food density, controls the entire simulation of the life cycle.

  10. A trait based dynamic energy budget approach to explore emergent microalgal community structure

    Science.gov (United States)

    Cheng, Y.; Bouskill, N.; Karaoz, U.; Geng, H.; Lane, T.; Pett-Ridge, J.; Mayali, X.; Brodie, E.

    2015-12-01

    Microalgae play important roles in the global carbon budget. Phytoplankton, including microalgae, are responsible for around 50% of global primary production, and also hold promise as a viable renewable biofuel source. Research has been underway for decades to realize the full potential of algal biofuels at the commercial scale, however, uni-algal ponds are typically threatened by collapse due to microalgal grazing and parasite invasions. Recently, it has been proposed that functionally diverse microalgal-bacterial communities can achieve high biomass and/or lipid yields, and are more stable (less susceptible to invasion) than a monoculture. Similar positive diversity-productivity relationships have been observed in a wide range of ecosystem studies, but the purposeful maintenance of a diverse microbiome is less common in managed systems. In our work, a trait based dynamic energy budget model was developed to explore emergent microalgal community structure under various environmental (e.g. light, temperature, nutrient availability) conditions. The complex algal community can be reduced into functional groups (guilds). Each guild (algae or bacteria) is characterized by distinct physiological traits (e.g. nutrient requirement, growth rate, substrate affinity, lipid production) constrained by biochemical trade-offs. These trait values are derived from literature and information encoded in genomic data. Metabolism of the algae and the bacterial species (symbiotic or non-symbiotic) are described within a dynamic energy budget framework. The model offers a mechanistic framework to predict the optimal microalgal community assemblage towards high productivity and resistance to invasion under prevailing environmental conditions.

  11. Modelling mussel growth in ecosystems with low suspended matter loads using a Dynamic Energy Budget approach

    Science.gov (United States)

    Duarte, P.; Fernández-Reiriz, M. J.; Labarta, U.

    2012-01-01

    The environmental and the economic importance of shellfish stimulated a great deal of studies on their physiology over the last decades, with many attempts to model their growth. The first models developed to simulate bivalve growth were predominantly based on the Scope For Growth ( SFG) paradigm. In the last years there has been a shift towards the Dynamic Energy Budget ( DEB) paradigm. The general objective of this work is contributing to the evaluation of different approaches to simulate bivalve growth in low seston waters by: (i) implementing a model to simulate mussel growth in low suspended matter ecosystems based on the DEB theory (Kooijman, S.A.L.M., 2000. Dynamic and energy mass budgets in biological systems, Cambridge University Press); (ii) comparing and discussing different approaches to simulate feeding processes, in the light of recently published works both on experimental physiology and physiology modeling; (iii) comparing and discussing results obtained with a model based on EMMY ( Scholten and Smaal, 1998). The model implemented allowed to successfully simulate mussel feeding and shell length growth in two different Galician Rias. Obtained results together with literature data suggest that modeling of bivalve feeding should incorporate physiologic feed-backs related with food digestibility. In spite of considerable advances in bivalve modeling a number of issues is yet to be resolved, with emphasis on the way food sources are represented and feeding processes formulated.

  12. Blue mussel (Mytilus edulis) growth at various salinity regime determined by a Dynamic Energy Budget model

    DEFF Research Database (Denmark)

    Saurel, Camille; Maar, Marie; Landes, Anja

    such as food supply, temperature and salinity. In the Baltic Sea - highly disturbed eutrophied environment-mussel growth efficiency is limited due to the very low levels of salinity and in area where the salinity is below 8 psu, mussels appear on a dwarf form. The aim of the present study was to incorporate...... the effects of low salinity into an eco-physiological model of blue mussels and to identify areas suitable for cost-effective mussel production for mitigation culture. A standard Dynamic Energy Budget (DEB) model was modified with respect to i) the morphological parameters (DW/WW-ratio, shape factor), ii......) change in ingestion rate and iii) metabolic costs due to osmotic regulatory mechanisms to adapt in different salinity environments. The modified DEB model was validated with experimental data from different locations in the Western Baltic Sea including the Limfjorden, with salinities ranging from 8...

  13. A coupled biogeochemical-Dynamic Energy Budget model as a tool for managing fish production ponds.

    Science.gov (United States)

    Serpa, Dalila; Pousão-Ferreira, Pedro; Caetano, Miguel; Cancela da Fonseca, Luís; Dinis, Maria Teresa; Duarte, Pedro

    2013-10-01

    The sustainability of semi-intensive aquaculture relies on management practices that simultaneously improve production efficiency and minimize the environmental impacts of this activity. The purpose of the present work was to develop a mathematical model that reproduced the dynamics of a semi-intensive fish earth pond, to simulate different management scenarios for optimizing fish production. The modeling approach consisted of coupling a biogeochemical model that simulated the dynamics of the elements that are more likely to affect fish production and cause undesirable environmental impacts (nitrogen, phosphorus and oxygen) to a fish growth model based on the Dynamic Energy Budget approach. The biogeochemical sub-model successfully simulated most water column and sediment variables. A good model fit was also found between predicted and observed white seabream (Diplodus sargus) growth data over a production cycle. In order to optimize fish production, different management scenarios were analysed with the model (e.g. increase stocking densities, decrease/increase water exchange rates, decrease/increase feeding rates, decrease phosphorus content in fish feeds, increase food assimilation efficiency and decrease pellets sinking velocity) to test their effects on the pond environment as well as on fish yields and effluent nutrient discharges. Scenarios were quantitatively evaluated and compared using the Analytical Hierarchical Process (AHP) methodology. The best management options that allow the maximization of fish production while maintaining a good pond environment and minimum impacts on the adjacent coastal system were to double standard stocking densities and to improve food assimilation efficiency.

  14. Dynamic Energy Budget model parameter estimation for the bivalve Mytilus californianus: Application of the covariation method

    Science.gov (United States)

    Matzelle, A.; Montalto, V.; Sarà, G.; Zippay, M.; Helmuth, B.

    2014-11-01

    Dynamic Energy Budget (DEB) models serve as a powerful tool for describing the flow of energy through organisms from assimilation of food to utilization for maintenance, growth and reproduction. The DEB theory has been successfully applied to several bivalve species to compare bioenergetic and physiological strategies for the utilization of energy. In particular, mussels within the Mytilus edulis complex (M. edulis, M. galloprovincialis, and M. trossulus) have been the focus of many studies due to their economic and ecological importance, and their worldwide distribution. However, DEB parameter values have never been estimated for Mytilus californianus, a species that is an ecological dominant on rocky intertidal shores on the west coast of North America and which likely varies considerably from mussels in the M. edulis complex in its physiology. We estimated a set of DEB parameters for M. californianus using the covariation method estimation procedure and compared these to parameter values from other bivalve species. Model parameters were used to compare sensitivity to environmental variability among species, as a first examination of how strategies for physiologically contending with environmental change by M. californianus may differ from those of other bivalves. Results suggest that based on the parameter set obtained, M. californianus has favorable energetic strategies enabling it to contend with a range of environmental conditions. For instance, the allocation fraction of reserve to soma (κ) is among the highest of any bivalves, which is consistent with the observation that this species can survive over a wide range of environmental conditions, including prolonged periods of starvation.

  15. The "covariation method" for estimating the parameters of the standard Dynamic energy Budget model I: Philosophy and apporach

    NARCIS (Netherlands)

    Lika, K.; Kearney, M.R.; Freitas, V.; Veer, van der H.W.; Meer, van der J.; Wijsman, J.W.M.; Pecquerie, L.; Kooijman, S.A.L.M.

    2011-01-01

    The Dynamic Energy Budget (DEB) theory for metabolic organisation captures the processes of development, growth, maintenance, reproduction and ageing for any kind of organism throughout its life-cycle. However, the application of DEB theory is challenging because the state variables and parameters a

  16. The "covariation method" for estimating the parameters of the standard Dynamic Energy Budget model I: Philosophy and approach

    NARCIS (Netherlands)

    Lika, K.; Kearney, M.R.; Freitas, V.; van der Veer, H.W.; van der Meer, J.; Wijsman, J.W.M.; Pecquerie, L.; Kooijman, S.A.L.M.

    2011-01-01

    The Dynamic Energy Budget (DEB) theory for metabolic organisation captures the processes of development, growth, maintenance, reproduction and ageing for any kind of organism throughout its life-cycle. However, the application of DEB theory is challenging because the state variables and parameters a

  17. Estimation of dynamic energy budget parameters for the Mediterranean toothcarp (Aphanius fasciatus)

    Science.gov (United States)

    Rinaldi, A.; Montalto, V.; Lika, K.; Sanfilippo, M.; Manganaro, A.; Sarà, G.

    2014-11-01

    Organisms adopt different sets of physiological, behavioural and morphological trade-offs in order to cope with natural environmental fluctuations. This has consequential rebounds on ecological processes and population dynamics. Such aspects become crucial for sex-dimorphic species, where sex-specific growth variation could mirror different tactics both in energy acquisition and investment between maximum female and male body size with cascading effects on population demography. To date, different approaches have been used in order to understand the causes of individual growth rate changes in ectotherm indeterminate growers, most of which failed. Here, we propose the use of a mechanistic model based on the Dynamic Energy Budget theory (DEB; Koojiman, 2010) to investigate potential differences in energy allocation strategies adopted by individuals of different genders with the Mediterranean toothcarp Aphanius fasciatus (Valenciennes, 1821) as the model species. We collected literature and field data in order to study differences in energy allocation strategies between females and males of the same species by generating projections of possible growth performances: (1) throughout their entire life span and (2) under a context of varying functional responses. Generally, the present exercise of simulations returned different patterns of growth performance among females and males of A. fasciatus, with the former being able to better optimize energetic trade-offs under optimal environmental conditions. The present DEB parameterization exercise represents an essential step towards developing a mechanistic approach to depict metabolic strategies, which are at the base of observed sexual differences, and how such differences may impair ultimate fitness at individual and, therefore, population levels.

  18. Comparative energetics of the 5 fish classes on the basis of dynamic energy budgets

    Science.gov (United States)

    Kooijman, Sebastiaan A. L. M.; Lika, Konstadia

    2014-11-01

    The eco-physiology of taxa in an evolutionary context can best be studied by a comparison of parameter values of the energy budget that accounts for the inter-relationships of all endpoints of energy allocation. To this end, the parameters of the standard Dynamic Energy Budget (DEB) model have been estimated for 64 fish species from all 5 fish classes. The values are compared with those of the whole collection of over 300 species from most large animal phyla. The goodness of fit was very high, but the data were rather incomplete, compared with the energy balance for full life cycles. Metabolic acceleration, where maximum specific assimilation and energy conductance increase with length between birth and metabolic metamorphosis, seems to be confined, among fish, to some species of ray-finned fish and seems to have evolved independently several times in this taxon. We introduce a new altriciality index, i.e. the ratio of the maturity levels at puberty and birth, and conclude that ray-finned fish are more altricial, and cartilaginous fish are more precocial than typical animals. Fish allocate more to reproduction than typical animals. Parameter estimates show that 66% of the fish species considered invest less in reproduction than the value that would maximize the reproduction rate of fully grown individuals. By comparison, 85% of all the animal species in the collection do so. Consistent with theoretical expectations, allocation to reproduction and maturity at birth increase with cubed (ultimate structural) length, and reserve capacity with length for non-ray-finned fish, with the consequence that reproduction rate decreases with length. Ray-finned fish, however, have a maturity at birth and a reserve capacity almost independent of length, and a reproduction rate that increases with cubed length. Reserve capacity tends to increase with ultimate length for non-accelerating ray-finned fish, but not for accelerating species. Reproduction rate decreases inter

  19. Stylized facts in microalgal growth: interpretation in a dynamic energy budget context.

    Science.gov (United States)

    Lorena, António; Marques, Gonçalo M; Kooijman, S A L M; Sousa, Tânia

    2010-11-12

    A dynamic energy budget (DEB) model for microalgae is proposed. This model deviates from the standard DEB model as it needs more reserves to cope with the variation of assimilation pathways, requiring a different approach to growth based on the synthesizing unit (SU) theory for multiple substrates. It is shown that the model is able to accurately predict experimental data in constant and light-varying conditions with most of the parameter values taken directly from the literature. Also, model simulations are shown to be consistent with stylized facts (SFs) concerning NC ratio. These SFs are reinterpreted and the general conclusion is that all forcing variables (dilution rate, temperature and irradiance) impose changes in the nitrogen or carbon limitation status of the population, and consequently on reserve densities. Model predictions are also evaluated in comparison with SFs on chlorophyll concentration. It is proposed that an extra structure, more dependent on the nitrogen reserve, is required to accurately model chlorophyll dynamics. Finally, SFs concerning extracellular polymeric substances (EPSs) production by benthic diatoms are collected and interpreted and a formulation based on product synthesis and rejection flux is proposed for the EPSs production rate.

  20. Coupled dynamics of energy budget and population growth of tilapia in response to pulsed waterborne copper.

    Science.gov (United States)

    Chen, Wei-Yu; Lin, Chia-Jung; Ju, Yun-Ru; Tsai, Jeng-Wei; Liao, Chung-Min

    2012-11-01

    The impact of environmentally pulsed metal exposure on population dynamics of aquatic organisms remains poorly understood and highly unpredictable. The purpose of our study was to link a dynamic energy budget model to a toxicokinetic/toxicodynamic (TK/TD). We used the model to investigate tilapia population dynamics in response to pulsed waterborne copper (Cu) assessed with available empirical data. We mechanistically linked the acute and chronic bioassays of pulsed waterborne Cu at the scale of individuals to tilapia populations to capture the interaction between environment and population growth and reproduction. A three-stage matrix population model of larva-juvenile-adult was used to project offspring production through two generations. The estimated median population growth rate (λ) decreased from 1.0419 to 0.9991 under pulsed Cu activities ranging from 1.6 to 2.0 μg L(-1). Our results revealed that the influence on λ was predominately due to changes in the adult survival and larval survival and growth functions. We found that pulsed timing has potential impacts on physiological responses and population abundance. Our study indicated that increasing time intervals between first and second pulses decreased mortality and growth inhibition of tilapia populations, indicating that during long pulsed intervals tilapia may have enough time to recover. Our study concluded that the bioenergetics-based matrix population methodology could be employed in a life-cycle toxicity assessment framework to explore the effect of stage-specific mode-of-actions in population response to pulsed contaminants.

  1. Simultaneous multi-wavelength observations of Saturn's aurorae : energy budget and magnetospheric dynamics

    Science.gov (United States)

    Lamy, L.

    2011-10-01

    Similarly to other magnetized planets, accelerated electrons entering Saturn's auroral regions generate powerful emissions. They divide into Ultraviolet (UV) and Infrared (IR) aurorae, originating from collisions with the upper atmosphere, and Saturn's Kilometric Radiation (SKR), radiated by an electron cyclotron resonance above the atmosphere up a few Saturn's radii (Rs). Previous studies have identified a large scale conjugacy between radio and UV, as well as IR and UV auroral emissions. Here, we investigate two days of observations of Saturn's aurorae at radio, UV and IR wavelengths, by the Cassini RPWS, UVIS and VIMS instruments, and their relationship with a reservoir of equatorial energetic particles mapped by energetic neutral atoms (ENA), as measured by MIMI-INCA (see Figure ??). This interval of time reveals a series of regular SKR modulations at the southern SKR phase, and interestingly includes an unusual (while also regular) enhancement of the auroral activity observed simultaneously at all wavelengths. This event is likely to illustrate a (regular) nightside injection of energetic particles, possibly induced by a plasmoid ejection, then co-rotating with the planet at the southern SKR period, while feeding an extended longitudinal sector of intense auroral emissions. We analyze quantitatively complementary informations brought by these different datasets in terms of energy budget transferred to the southern auroral region, as well as magnetospheric dynamics, in order to address the nature and the scheme of the Saturn's southern rotational modulation.

  2. The AquaDEB project: Physiological flexibility of aquatic animals analysed with a generic dynamic energy budget model (phase II)

    OpenAIRE

    Alunno-Bruscia, Marianne; Veer, Henk van der; Kooijman, S.A.L.M.

    2011-01-01

    This second special issue of the Journal of Sea Research on development and applications of Dynamic Energy Budget (DEB) theory concludes the European Research Project AquaDEB (2007–2011). In this introductory paper we summarise the progress made during the running time of this 5 years’ project, present context for the papers in this volume and discuss future directions. The main scientific objectives in AquaDEB were (i) to study and compare the sensitivity of aquatic species (mainly molluscs ...

  3. Towards the determination of Mytilus edulis food preferences using the dynamic energy budget (DEB theory.

    Directory of Open Access Journals (Sweden)

    Coralie Picoche

    Full Text Available The blue mussel, Mytilus edulis, is a commercially important species, with production based on both fisheries and aquaculture. Dynamic Energy Budget (DEB models have been extensively applied to study its energetics but such applications require a deep understanding of its nutrition, from filtration to assimilation. Being filter feeders, mussels show multiple responses to temporal fluctuations in their food and environment, raising questions that can be investigated by modeling. To provide a better insight into mussel-environment interactions, an experiment was conducted in one of the main French growing zones (Utah Beach, Normandy. Mussel growth was monitored monthly for 18 months, with a large number of environmental descriptors measured in parallel. Food proxies such as chlorophyll a, particulate organic carbon and phytoplankton were also sampled, in addition to non-nutritious particles. High-frequency physical data recording (e.g., water temperature, immersion duration completed the habitat description. Measures revealed an increase in dry flesh mass during the first year, followed by a high mass loss, which could not be completely explained by the DEB model using raw external signals. We propose two methods that reconstruct food from shell length and dry flesh mass variations. The former depends on the inversion of the growth equation while the latter is based on iterative simulations. Assemblages of food proxies are then related to reconstructed food input, with a special focus on plankton species. A characteristic contribution is attributed to these sources to estimate nutritional values for mussels. M. edulis shows no preference between most plankton life history traits. Selection is based on the size of the ingested particles, which is modified by the volume and social behavior of plankton species. This finding reveals the importance of diet diversity and both passive and active selections, and confirms the need to adjust DEB models to

  4. Towards the determination of Mytilus edulis food preferences using the dynamic energy budget (DEB) theory.

    Science.gov (United States)

    Picoche, Coralie; Le Gendre, Romain; Flye-Sainte-Marie, Jonathan; Françoise, Sylvaine; Maheux, Frank; Simon, Benjamin; Gangnery, Aline

    2014-01-01

    The blue mussel, Mytilus edulis, is a commercially important species, with production based on both fisheries and aquaculture. Dynamic Energy Budget (DEB) models have been extensively applied to study its energetics but such applications require a deep understanding of its nutrition, from filtration to assimilation. Being filter feeders, mussels show multiple responses to temporal fluctuations in their food and environment, raising questions that can be investigated by modeling. To provide a better insight into mussel-environment interactions, an experiment was conducted in one of the main French growing zones (Utah Beach, Normandy). Mussel growth was monitored monthly for 18 months, with a large number of environmental descriptors measured in parallel. Food proxies such as chlorophyll a, particulate organic carbon and phytoplankton were also sampled, in addition to non-nutritious particles. High-frequency physical data recording (e.g., water temperature, immersion duration) completed the habitat description. Measures revealed an increase in dry flesh mass during the first year, followed by a high mass loss, which could not be completely explained by the DEB model using raw external signals. We propose two methods that reconstruct food from shell length and dry flesh mass variations. The former depends on the inversion of the growth equation while the latter is based on iterative simulations. Assemblages of food proxies are then related to reconstructed food input, with a special focus on plankton species. A characteristic contribution is attributed to these sources to estimate nutritional values for mussels. M. edulis shows no preference between most plankton life history traits. Selection is based on the size of the ingested particles, which is modified by the volume and social behavior of plankton species. This finding reveals the importance of diet diversity and both passive and active selections, and confirms the need to adjust DEB models to different

  5. Storm- Time Dynamics of Ring Current Protons: Implications for the Long-Term Energy Budget in the Inner Magnetosphere.

    Science.gov (United States)

    Gkioulidou, M.; Ukhorskiy, A. Y.; Mitchell, D. G.; Lanzerotti, L. J.

    2015-12-01

    The ring current energy budget plays a key role in the global electrodynamics of Earth's space environment. Pressure gradients developed in the inner magnetosphere can shield the near-Earth region from solar wind-induced electric fields. The distortion of Earth's magnetic field due to the ring current affects the dynamics of particles contributing both to the ring current and radiation belts. Therefore, understanding the long-term evolution of the inner magnetosphere energy content is essential. We have investigated the evolution of ring current proton pressure (7 - 600 keV) in the inner magnetosphere based on data from the Radiation Belt Storm Probes Ion Composition Experiment (RBSPICE) instrument aboard Van Allen Probe B throughout the year 2013. We find that although the low-energy component of the protons (governed by convective timescales and is very well correlated with the Dst index, the high-energy component (>100 keV) varies on much longer timescales and shows either no or anti-correlation with the Dst index. Interestingly, the contributions of the high- and low-energy protons to the total energy content are comparable. Our results indicate that the proton dynamics, and as a consequence the total energy budget in the inner magnetosphere (inside geosynchronous orbit), is not strictly controlled by storm-time timescales as those are defined by the Dst index.

  6. Autotrophs' challenge to Dynamic Energy Budget theory: Comment on ;Physics of metabolic organization; by Marko Jusup et al.

    Science.gov (United States)

    Geček, Sunčana

    2017-03-01

    Jusup and colleagues in the recent review on physics of metabolic organization [1] discuss in detail motivational considerations and common assumptions of Dynamic Energy Budget (DEB) theory, supply readers with a practical guide to DEB-based modeling, demonstrate the construction and dynamics of the standard DEB model, and illustrate several applications. The authors make a step forward from the existing literature by seamlessly bridging over the dichotomy between (i) thermodynamic foundations of the theory (which are often more accessible and understandable to physicists and mathematicians), and (ii) the resulting bioenergetic models (mostly used by biologists in real-world applications).

  7. Development of a dynamic energy budget modeling approach to investigate the effects of temperature and resource limitation on mercury bioaccumulation in Fundulus heteroclitus.

    Science.gov (United States)

    Dynamic energy budget (DEB) theory provides a generalizable and broadly applicable framework to connect sublethal toxic effects on individuals to changes in population survival and growth. To explore this approach, we are developing growth and bioaccumulation studies that contrib...

  8. Development of a dynamic energy budget modeling approach to investigate the effects of temperature and resource limitation on mercury bioaccumulation in Fundulus heteroclitus-presentation

    Science.gov (United States)

    Dynamic energy budget (DEB) theory provides a generalizable and broadly applicable framework to connect sublethal toxic effects on individuals to changes in population survival and growth. To explore this approach, we are conducting growth and bioaccumulation studies that contrib...

  9. Qualitative use of Dynamic Energy Budget theory in ecotoxicology. Case study on oil contamination and Arctic copepods

    Science.gov (United States)

    Klok, Chris; Hjorth, Morten; Dahllöf, Ingela

    2012-10-01

    The Dynamic Energy Budget (DEB) theory provides a logic and consistent framework to evaluate ecotoxicological test results. Currently this framework is not regularly applied in ecotoxicology given perceived complexity and data needs. However, even in the case of low data availability the DEB theory is already useful. In this paper we apply the DEB theory to evaluate the results in three previously published papers on the effects of PAHs on Arctic copepods. Since these results do not allow for a quantitative application we used DEB qualitatively. The ecotoxicological results were thereby set in a wider ecological context and we found a logical explanation for an unexpected decline in hatching success described in one of these papers. Moreover, the DEB evaluation helped to derive relevant ecological questions that can guide future experimental work on this subject.

  10. Growth potential of blue mussels (M. edulis) exposed to different salinities evaluated by a Dynamic Energy Budget model

    DEFF Research Database (Denmark)

    Maar, Marie; Saurel, Camille; Landes, Anja

    2015-01-01

    For bluemussels,Mytilus edulis, onemajor constrain in the Baltic Sea is the low salinities that reduce the efficiency of mussel production. However, the effects of living in low and variable salinity regimes are rarely considered in models describing mussel growth. The aim of the present study...... was to incorporate the effects of low salinity into an eco-physiological model of blue mussels and to identify areas suitable for mussel production. A Dynamic Energy Budget (DEB) model was modified with respect to i) the morphological parameters (DW/WW-ratio, shape factor), ii) change in ingestion rate and iii...... symptoms or as part of integrated multi-trophic aquaculture production. The model can also be used to predict the effects of salinity changes on mussel populations e.g. in climate change studies...

  11. Analyzing variations in life-history traits of Pacific salmon in the context of Dynamic Energy Budget (DEB) theory

    Science.gov (United States)

    Pecquerie, Laure; Johnson, Leah R.; Kooijman, Sebastiaan A. L. M.; Nisbet, Roger M.

    2011-11-01

    To determine the response of Pacific salmon ( Oncorhynchus spp.) populations to environmental change, we need to understand impacts on all life stages. However, an integrative and mechanistic approach is particularly challenging for Pacific salmon as they use multiple habitats (river, estuarine and marine) during their life cycle. Here we develop a bioenergetic model that predicts development, growth and reproduction of a Pacific salmon in a dynamic environment, from an egg to a reproducing female, and that links female state to egg traits. This model uses Dynamic Energy Budget (DEB) theory to predict how life history traits vary among five species of Pacific salmon: Pink, Sockeye, Coho, Chum and Chinook. Supplemented with a limited number of assumptions on anadromy and semelparity and external signals for migrations, the model reproduces the qualitative patterns in egg size, fry size and fecundity both at the inter- and intra-species levels. Our results highlight how modeling all life stages within a single framework enables us to better understand complex life-history patterns. Additionally we show that body size scaling relationships implied by DEB theory provide a simple way to transfer model parameters among Pacific salmon species, thus providing a generic approach to study the impact of environmental conditions on the life cycle of Pacific salmon.

  12. Modeling the eco-physiology of the purple mauve stinger, Pelagia noctiluca using Dynamic Energy Budget theory

    Science.gov (United States)

    Augustine, Starrlight; Rosa, Sara; Kooijman, Sebastiaan A. L. M.; Carlotti, François; Poggiale, Jean-Christophe

    2014-11-01

    Parameters for the standard Dynamic Energy Budget (DEB) model were estimated for the purple mauve stinger, Pelagia noctiluca, using literature data. Overall, the model predictions are in good agreement with data covering the full life-cycle. The parameter set we obtain suggests that P. noctiluca is well adapted to survive long periods of starvation since the predicted maximum reserve capacity is extremely high. Moreover we predict that the reproductive output of larger individuals is relatively insensitive to changes in food level while wet mass and length are. Furthermore, the parameters imply that even if food were scarce (ingestion levels only 14% of the maximum for a given size) an individual would still mature and be able to reproduce. We present detailed model predictions for embryo development and discuss the developmental energetics of the species such as the fact that the metabolism of ephyrae accelerates for several days after birth. Finally we explore a number of concrete testable model predictions which will help to guide future research. The application of DEB theory to the collected data allowed us to conclude that P. noctiluca combines maximizing allocation to reproduction with rather extreme capabilities to survive starvation. The combination of these properties might explain why P. noctiluca is a rapidly growing concern to fisheries and tourism.

  13. Challenges for dynamic energy budget theory. Comment on ;Physics of metabolic organization; by Marko Jusup et al.

    Science.gov (United States)

    Nisbet, Roger M.

    2017-03-01

    Jusup et al. [1] provide a comprehensive review of Dynamic Energy Budget (DEB) theory - a theory of metabolic organization that has its roots in a model by S.A.L.M Kooijman [2] and has evolved over three decades into a remarkable general theory whose use appears to be growing exponentially. The definitive text on DEB theory [3] is a challenging (though exceptionally rewarding) read, and previous reviews (e.g. [4,5]) have provided focused summaries of some of its main themes, targeted at specific groups of readers. The strong case for a further review is well captured in the abstract: ;Hitherto, the foundations were more accessible to physicists or mathematicians, and the applications to biologists, causing a dichotomy in what always should have been a single body of work.; In response to this need, Jusup et al. provide a review that combines a lucid, rigorous exposition of the core components of DEB theory with a diverse collection of DEB applications. They also highlight some recent advances, notably the rapidly growing on-line database of DEB model parameters (451 species on 15 August 2016 according to [1], now, just a few months later, over 500 species).

  14. The evolving energy budget of accretionary wedges

    Science.gov (United States)

    McBeck, Jessica; Cooke, Michele; Maillot, Bertrand; Souloumiac, Pauline

    2017-04-01

    The energy budget of evolving accretionary systems reveals how deformational processes partition energy as faults slip, topography uplifts, and layer-parallel shortening produces distributed off-fault deformation. The energy budget provides a quantitative framework for evaluating the energetic contribution or consumption of diverse deformation mechanisms. We investigate energy partitioning in evolving accretionary prisms by synthesizing data from physical sand accretion experiments and numerical accretion simulations. We incorporate incremental strain fields and cumulative force measurements from two suites of experiments to design numerical simulations that represent accretionary wedges with stronger and weaker detachment faults. One suite of the physical experiments includes a basal glass bead layer and the other does not. Two physical experiments within each suite implement different boundary conditions (stable base versus moving base configuration). Synthesizing observations from the differing base configurations reduces the influence of sidewall friction because the force vector produced by sidewall friction points in opposite directions depending on whether the base is fixed or moving. With the numerical simulations, we calculate the energy budget at two stages of accretion: at the maximum force preceding the development of the first thrust pair, and at the minimum force following the development of the pair. To identify the appropriate combination of material and fault properties to apply in the simulations, we systematically vary the Young's modulus and the fault static and dynamic friction coefficients in numerical accretion simulations, and identify the set of parameters that minimizes the misfit between the normal force measured on the physical backwall and the numerically simulated force. Following this derivation of the appropriate material and fault properties, we calculate the components of the work budget in the numerical simulations and in the

  15. Applying Dynamic Energy Budget (DEB) theory to simulate growth and bio-energetics of blue mussels under low seston conditions

    Science.gov (United States)

    Rosland, R.; Strand, Ø.; Alunno-Bruscia, M.; Bacher, C.; Strohmeier, T.

    2009-08-01

    A Dynamic Energy Budget (DEB) model for simulation of growth and bioenergetics of blue mussels ( Mytilus edulis) has been tested in three low seston sites in southern Norway. The observations comprise four datasets from laboratory experiments (physiological and biometrical mussel data) and three datasets from in situ growth experiments (biometrical mussel data). Additional in situ data from commercial farms in southern Norway were used for estimation of biometrical relationships in the mussels. Three DEB parameters (shape coefficient, half saturation coefficient, and somatic maintenance rate coefficient) were estimated from experimental data, and the estimated parameters were complemented with parameter values from literature to establish a basic parameter set. Model simulations based on the basic parameter set and site specific environmental forcing matched fairly well with observations, but the model was not successful in simulating growth at the extreme low seston regimes in the laboratory experiments in which the long period of negative growth caused negative reproductive mass. Sensitivity analysis indicated that the model was moderately sensitive to changes in the parameter and initial conditions. The results show the robust properties of the DEB model as it manages to simulate mussel growth in several independent datasets from a common basic parameter set. However, the results also demonstrate limitations of Chl a as a food proxy for blue mussels and limitations of the DEB model to simulate long term starvation. Future work should aim at establishing better food proxies and improving the model formulations of the processes involved in food ingestion and assimilation. The current DEB model should also be elaborated to allow shrinking in the structural tissue in order to produce more realistic growth simulations during long periods of starvation.

  16. The AquaDEB project: Physiological flexibility of aquatic animals analysed with a generic dynamic energy budget model (phase II)

    Science.gov (United States)

    Alunno-Bruscia, Marianne; van der Veer, Henk W.; Kooijman, Sebastiaan A. L. M.

    2011-11-01

    This second special issue of the Journal of Sea Research on development and applications of Dynamic Energy Budget (DEB) theory concludes the European Research Project AquaDEB (2007-2011). In this introductory paper we summarise the progress made during the running time of this 5 years' project, present context for the papers in this volume and discuss future directions. The main scientific objectives in AquaDEB were (i) to study and compare the sensitivity of aquatic species (mainly molluscs and fish) to environmental variability within the context of DEB theory for metabolic organisation, and (ii) to evaluate the inter-relationships between different biological levels (individual, population, ecosystem) and temporal scales (life cycle, population dynamics, evolution). AquaDEB phase I focussed on quantifying bio-energetic processes of various aquatic species ( e.g. molluscs, fish, crustaceans, algae) and phase II on: (i) comparing of energetic and physiological strategies among species through the DEB parameter values and identifying the factors responsible for any differences in bioenergetics and physiology; (ii) considering different scenarios of environmental disruption (excess of nutrients, diffuse or massive pollution, exploitation by man, climate change) to forecast effects on growth, reproduction and survival of key species; (iii) scaling up the models for a few species from the individual level up to the level of evolutionary processes. Apart from the three special issues in the Journal of Sea Research — including the DEBIB collaboration (see vol. 65 issue 2), a theme issue on DEB theory appeared in the Philosophical Transactions of the Royal Society B (vol 365, 2010); a large number of publications were produced; the third edition of the DEB book appeared (2010); open-source software was substantially expanded (over 1000 functions); a large open-source systematic collection of ecophysiological data and DEB parameters has been set up; and a series of DEB

  17. Quantifying the impacts of land surface schemes and dynamic vegetation on the model dependency of projected changes in surface energy and water budgets

    Science.gov (United States)

    Yu, Miao; Wang, Guiling; Chen, Haishan

    2016-03-01

    Assessing and quantifying the uncertainties in projected future changes of energy and water budgets over land surface are important steps toward improving our confidence in climate change projections. In this study, the contribution of land surface models to the inter-GCM variation of projected future changes in land surface energy and water fluxes are assessed based on output from 19 global climate models (GCMs) and offline Community Land Model version 4 (CLM4) simulations driven by meteorological forcing from the 19 GCMs. Similar offline simulations using CLM4 with its dynamic vegetation submodel are also conducted to investigate how dynamic vegetation feedback, a process that is being added to more earth system models, may amplify or moderate the intermodel variations of projected future changes. Projected changes are quantified as the difference between the 2081-2100 period from the Representative Concentration Pathway 8.5 (RCP8.5) future experiment and the 1981-2000 period from the historical simulation. Under RCP8.5, projected changes in surface water and heat fluxes show a high degree of model dependency across the globe. Although precipitation is very likely to increase in the high latitudes of the Northern Hemisphere, a high degree of model-related uncertainty exists for evapotranspiration, soil water content, and surface runoff, suggesting discrepancy among land surface models (LSMs) in simulating the surface hydrological processes and snow-related processes. Large model-related uncertainties for the surface water budget also exist in the Tropics including southeastern South America and Central Africa. These uncertainties would be reduced in the hypothetical scenario of a single near-perfect land surface model being used across all GCMs, suggesting the potential to reduce uncertainties through the use of more consistent approaches toward land surface model development. Under such a scenario, the most significant reduction is likely to be seen in the

  18. Estancia Basin dynamic water budget.

    Energy Technology Data Exchange (ETDEWEB)

    Thomas, Richard P.

    2004-09-01

    The Estancia Basin lies about 30 miles to the east of Albuquerque, NM. It is a closed basin in terms of surface water and is somewhat isolated in terms of groundwater. Historically, the primary natural outlet for both surface water and groundwater has been evaporation from the salt lakes in the southeastern portion of the basin. There are no significant watercourses that flow into this basin and groundwater recharge is minimal. During the 20th Century, agriculture grew to become the major user of groundwater in the basin. Significant declines in groundwater levels have accompanied this agricultural use. Domestic and municipal use of the basin groundwater is increasing as Albuquerque population continues to spill eastward into the basin, but this use is projected to be less than 1% of agricultural use well into the 21st Century. This Water Budget model keeps track of the water balance within the basin. The model considers the amount of water entering the basin and leaving the basin. Since there is no significant surface water component within this basin, the balance of water in the groundwater aquifer constitutes the primary component of this balance. Inflow is based on assumptions for recharge made by earlier researchers. Outflow from the basin is the summation of the depletion from all basin water uses. The model user can control future water use within the basin via slider bars that set values for population growth, water system per-capita use, agricultural acreage, and the types of agricultural diversion. The user can also adjust recharge and natural discharge within the limits of uncertainty for those parameters. The model runs for 100 years beginning in 1940 and ending in 2040. During the first 55 years model results can be compared to historical data and estimates of groundwater use. The last 45 years are predictive. The model was calibrated to match to New Mexico Office of State Engineer (NMOSE) estimates of aquifer storage during the historical period by

  19. The AquaDEB project (phase I): Analysing the physiological flexibility of aquatic species and connecting physiological diversity to ecological and evolutionary processes by using Dynamic Energy Budgets

    Science.gov (United States)

    Alunno-Bruscia, Marianne; van der Veer, Henk W.; Kooijman, Sebastiaan A. L. M.

    2009-08-01

    The European Research Project AquaDEB (2007-2011, http://www.ifremer.fr/aquadeb/) is joining skills and expertise of some French and Dutch research institutes and universities to analyse the physiological flexibility of aquatic organisms and to link it to ecological and evolutionary processes within a common theoretical framework for quantitative bioenergetics [Kooijman, S.A.L.M., 2000. Dynamic energy and mass budgets in biological systems. Cambridge University Press, Cambridge]. The main scientific objectives in AquaDEB are i) to study and compare the sensitivity of aquatic species (mainly molluscs and fish) to environmental variability of natural or human origin, and ii) to evaluate the related consequences at different biological levels (individual, population, ecosystem) and temporal scales (life cycle, population dynamics, evolution). At mid-term life, the AquaDEB collaboration has already yielded interesting results by quantifying bio-energetic processes of various aquatic species (e.g. molluscs, fish, crustaceans, algae) with a single mathematical framework. It has also allowed to federate scientists with different backgrounds, e.g. mathematics, microbiology, ecology, chemistry, and working in different fields, e.g. aquaculture, fisheries, ecology, agronomy, ecotoxicology, climate change. For the two coming years, the focus of the AquaDEB collaboration will be in priority: (i) to compare energetic and physiological strategies among species through the DEB parameter values and to identify the factors responsible for any differences in bioenergetics and physiology; and to compare dynamic (DEB) versus static (SEB) energy models to study the physiological performance of aquatic species; (ii) to consider different scenarios of environmental disruption (excess of nutrients, diffuse or massive pollution, exploitation by man, climate change) to forecast effects on growth, reproduction and survival of key species; (iii) to scale up the models for a few species from

  20. Mass and energy budgets of animals: Behavioral and ecological implications

    Energy Technology Data Exchange (ETDEWEB)

    Porter, W.P.

    1991-11-01

    The two major aims of our lab are as follows: First, to develop and field-test general mechanistic models that predict animal life history characteristics as influenced by climate and the physical, physiological behavioral characteristics of species. This involves: understanding how animal time and energy budgets are affected by climate and animal properties; predicting growth and reproductive potential from time and energy budgets; predicting mortality based on climate and time and energy budgets; and linking these individual based models to population dynamics. Second to conduct empirical studies of animal physiological ecology, particularly the effects of temperature on time and energy budgets. The physiological ecology of individual animals is the key link between the physical environment and population-level phenomena. We address the macroclimate to microclimate linkage on a broad spatial scale; address the links between individuals and population dynamics for lizard species; test the endotherm energetics and behavior model using beaver; address the spatial variation in climate and its effects on individual energetics, growth and reproduction; and address patchiness in the environment and constraints they may impose on individual energetics, growth and reproduction. These projects are described individually in the following section. 24 refs., 9 figs.

  1. Global Energy and Water Budgets in MERRA

    Science.gov (United States)

    Bosilovich, Michael G.; Robertson, Franklin R.; Chen, Junye

    2010-01-01

    Reanalyses, retrospectively analyzing observations over climatological time scales, represent a merger between satellite observations and models to provide globally continuous data and have improved over several generations. Balancing the Earth s global water and energy budgets has been a focus of research for more than two decades. Models tend to their own climate while remotely sensed observations have had varying degrees of uncertainty. This study evaluates the latest NASA reanalysis, called the Modern Era Retrospective-analysis for Research and Applications (MERRA), from a global water and energy cycles perspective. MERRA was configured to provide complete budgets in its output diagnostics, including the Incremental Analysis Update (IAU), the term that represents the observations influence on the analyzed states, alongside the physical flux terms. Precipitation in reanalyses is typically sensitive to the observational analysis. For MERRA, the global mean precipitation bias and spatial variability are more comparable to merged satellite observations (GPCP and CMAP) than previous generations of reanalyses. Ocean evaporation also has a much lower value which is comparable to observed data sets. The global energy budget shows that MERRA cloud effects may be generally weak, leading to excess shortwave radiation reaching the ocean surface. Evaluating the MERRA time series of budget terms, a significant change occurs, which does not appear to be represented in observations. In 1999, the global analysis increments of water vapor changes sign from negative to positive, and primarily lead to more oceanic precipitation. This change is coincident with the beginning of AMSU radiance assimilation. Previous and current reanalyses all exhibit some sensitivity to perturbations in the observation record, and this remains a significant research topic for reanalysis development. The effect of the changing observing system is evaluated for MERRA water and energy budget terms.

  2. Influence of low and decreasing food levels on Daphnia -algal interactions: Numerical experiments with a new dynamic energy budget model

    NARCIS (Netherlands)

    Peeters, F.; Li, J.; Straile, D.; Rothhaupt, K.-O.; Vijverberg, J.

    2010-01-01

    Based on numerical experiments with a new physiologically structured population model we demonstrate that predator physiology under low food and under starving conditions can have substantial implications for population dynamics in predator–prey interactions. We focused on Daphnia-algae interactions

  3. Dynamic energy budget as a basis to model population-level effects of zinc-spiked sediments in the gastropod Valvata piscinalis.

    Science.gov (United States)

    Ducrot, Virginie; Péry, Alexandre R R; Mons, Raphaël; Quéau, Hervé; Charles, Sandrine; Garric, Jeanne

    2007-08-01

    This paper presents original toxicity test designs and mathematical models that may be used to assess the deleterious effects of toxicants on Valvata piscinalis (Mollusca, Gastropoda). Results obtained for zinc, used as a reference toxicant, are presented. The feeding behavior, juvenile survival, growth, age at puberty, onset of reproduction, number of breedings during the life cycle, and fecundity were significantly altered when the snails were exposed to zinc-spiked sediments. Dynamic energy budget models (DEBtox) adequately predicted the effects of zinc on the V. piscinalis life cycle. They also provided estimates for lifecycle parameters that were used to parameterize a demographic model, based on a Z-transformed life-cycle graph. The effect threshold for the population growth rate (lambda) was estimated at 259 mg/kg dry sediment of zinc, showing that significant changes in abundance may occur at environmental concentrations. Significant effects occurring just above this threshold value were mainly caused by the severe impairment of reproductive endpoints. Sensitivity analysis showed that the value of lambda depended mainly on the juvenile survival rate. The impairment of this latter parameter may result in extinction of V. piscinalis. Finally, the present study highlights advantages of the proposed modeling approach in V. piscinalis and possible transfer to other test species and contaminants.

  4. Estimating the impact of petroleum substances on survival in early life stages of cod (Gadus morhua) using the dynamic energy budget theory.

    Science.gov (United States)

    Klok, Chris; Nordtug, Trond; Tamis, Jacqueline E

    2014-10-01

    To estimate the impact of accidental oil-spills on cod fisheries a model framework is developed in which a Dynamic Energy Budget (DEB) model is applied to assess mortality caused by petroleum substances in early life stages. In this paper we report on a literature search and DEB analyses, aiming for cod specific DEB-parameters. Furthermore, we explored the relevance of Fathead minnow DEB-parameters as surrogate by comparing LC50 values calculated from DEB-parameters with literature. Cod specific DEB-parameters could not be estimated based on available literature. LC50 values calculated from Fathead minnow DEB-parameters were higher than literature LC50 for early life stages of fish. Applying an extrapolation factor of 50 to the DEB-parameters resulted in LC50 values that were below literature irrespective of life stage. Therefore, we propose to use the last as an estimate for early life stages in cod and recommend relevant experiments with individual petroleum substances on cod. Copyright © 2014 Elsevier Ltd. All rights reserved.

  5. Parameter Estimations of Dynamic Energy Budget (DEB Model over the Life History of a Key Antarctic Species: The Antarctic Sea Star Odontaster validus Koehler, 1906.

    Directory of Open Access Journals (Sweden)

    Antonio Agüera

    Full Text Available Marine organisms in Antarctica are adapted to an extreme ecosystem including extremely stable temperatures and strong seasonality due to changes in day length. It is now largely accepted that Southern Ocean organisms are particularly vulnerable to global warming with some regions already being challenged by a rapid increase of temperature. Climate change affects both the physical and biotic components of marine ecosystems and will have an impact on the distribution and population dynamics of Antarctic marine organisms. To predict and assess the effect of climate change on marine ecosystems a more comprehensive knowledge of the life history and physiology of key species is urgently needed. In this study we estimate the Dynamic Energy Budget (DEB model parameters for key benthic Antarctic species the sea star Odontaster validus using available information from literature and experiments. The DEB theory is unique in capturing the metabolic processes of an organism through its entire life cycle as a function of temperature and food availability. The DEB model allows for the inclusion of the different life history stages, and thus, becomes a tool that can be used to model lifetime feeding, growth, reproduction, and their responses to changes in biotic and abiotic conditions. The DEB model presented here includes the estimation of reproduction handling rules for the development of simultaneous oocyte cohorts within the gonad. Additionally it links the DEB model reserves to the pyloric caeca an organ whose function has long been ascribed to energy storage. Model parameters described a slowed down metabolism of long living animals that mature slowly. O. validus has a large reserve that-matching low maintenance costs- allow withstanding long periods of starvation. Gonad development is continuous and individual cohorts developed within the gonads grow in biomass following a power function of the age of the cohort. The DEB model developed here for O

  6. Parameter Estimations of Dynamic Energy Budget (DEB) Model over the Life History of a Key Antarctic Species: The Antarctic Sea Star Odontaster validus Koehler, 1906.

    Science.gov (United States)

    Agüera, Antonio; Collard, Marie; Jossart, Quentin; Moreau, Camille; Danis, Bruno

    2015-01-01

    Marine organisms in Antarctica are adapted to an extreme ecosystem including extremely stable temperatures and strong seasonality due to changes in day length. It is now largely accepted that Southern Ocean organisms are particularly vulnerable to global warming with some regions already being challenged by a rapid increase of temperature. Climate change affects both the physical and biotic components of marine ecosystems and will have an impact on the distribution and population dynamics of Antarctic marine organisms. To predict and assess the effect of climate change on marine ecosystems a more comprehensive knowledge of the life history and physiology of key species is urgently needed. In this study we estimate the Dynamic Energy Budget (DEB) model parameters for key benthic Antarctic species the sea star Odontaster validus using available information from literature and experiments. The DEB theory is unique in capturing the metabolic processes of an organism through its entire life cycle as a function of temperature and food availability. The DEB model allows for the inclusion of the different life history stages, and thus, becomes a tool that can be used to model lifetime feeding, growth, reproduction, and their responses to changes in biotic and abiotic conditions. The DEB model presented here includes the estimation of reproduction handling rules for the development of simultaneous oocyte cohorts within the gonad. Additionally it links the DEB model reserves to the pyloric caeca an organ whose function has long been ascribed to energy storage. Model parameters described a slowed down metabolism of long living animals that mature slowly. O. validus has a large reserve that-matching low maintenance costs- allow withstanding long periods of starvation. Gonad development is continuous and individual cohorts developed within the gonads grow in biomass following a power function of the age of the cohort. The DEB model developed here for O. validus allowed us to

  7. Modelling the growth of white seabream (Diplodus sargus) and gilthead seabream (Sparus aurata) in semi-intensive earth production ponds using the Dynamic Energy Budget approach

    Science.gov (United States)

    Serpa, Dalila; Ferreira, Pedro Pousão; Ferreira, Hugo; da Fonseca, Luís Cancela; Dinis, Maria Teresa; Duarte, Pedro

    2013-02-01

    Fish growth models may help understanding the influence of environmental, physiological and husbandry factors on fish production, providing crucial information to maximize the growth rates of cultivated species. The main objectives of this work were to: i) develop and implement an Individual Based Model using a Dynamic Energy Budget (IBM-DEB) approach to simulate the growth of two commercially important Sparidae species in semi-intensive earth ponds, the white seabream which is considered as a potential candidate for Mediterranean aquaculture and the gilthead seabream that has been cultivated since the early 80s; ii) evaluate which model parameters are more likely to affect fish performance, and iii) investigate which parameters might account for growth differences between the cultivated species. The model may be run in two modes: the "state variable" mode, in which an average fish is simulated with a particular parameter set and the "Individual Based Model" (IBM) mode that simulates a population of n fishes, each with its specific parameter set assigned randomly. The IBM mode has the advantage of allowing a quick model calibration and an evaluation of the parameter sets that produce the best fit between predicted and observed fish growth. Results revealed that the model reproduces reasonably well the growth of the two seabreams. Fish performance was mainly affected by parameters related to feed ingestion/assimilation and reserves utilization, suggesting that special attention should be taken in the estimation of these parameters when applying the model to other species. Comparing the DEB parameters set of the two sparids it seems that the white seabream's low growth rates are a result of higher maintenance costs and a lower feed assimilation efficiency. Hence, the development of new feed formulations may be crucial for the success of white seabream production in semi-intensive earth ponds.

  8. Dynamical influence of gravity waves generated by the Vestfjella Mountains in Antarctica: radar observations, fine-scale modelling and kinetic energy budget analysis

    Directory of Open Access Journals (Sweden)

    Joel Arnault

    2012-02-01

    Full Text Available Gravity waves generated by the Vestfjella Mountains (in western Droning Maud Land, Antarctica, southwest of the Finnish/Swedish Aboa/Wasa station have been observed with the Moveable atmospheric radar for Antarctica (MARA during the SWEDish Antarctic Research Programme (SWEDARP in December 2007/January 2008. These radar observations are compared with a 2-month Weather Research Forecast (WRF model experiment operated at 2 km horizontal resolution. A control simulation without orography is also operated in order to separate unambiguously the contribution of the mountain waves on the simulated atmospheric flow. This contribution is then quantified with a kinetic energy budget analysis computed in the two simulations. The results of this study confirm that mountain waves reaching lower-stratospheric heights break through convective overturning and generate inertia gravity waves with a smaller vertical wavelength, in association with a brief depletion of kinetic energy through frictional dissipation and negative vertical advection. The kinetic energy budget also shows that gravity waves have a strong influence on the other terms of the budget, i.e. horizontal advection and horizontal work of pressure forces, so evaluating the influence of gravity waves on the mean-flow with the vertical advection term alone is not sufficient, at least in this case. We finally obtain that gravity waves generated by the Vestfjella Mountains reaching lower stratospheric heights generally deplete (create kinetic energy in the lower troposphere (upper troposphere–lower stratosphere, in contradiction with the usual decelerating effect attributed to gravity waves on the zonal circulation in the upper troposphere–lower stratosphere.

  9. Responses of Cloud Type Distributions to the Large-Scale Dynamical Circulation: Water Budget-Related Dynamical Phase Space and Dynamical Regimes

    Science.gov (United States)

    Wong, Sun; Del Genio, Anthony; Wang, Tao; Kahn, Brian; Fetzer, Eric J.; L'Ecuyer, Tristan S.

    2015-01-01

    Goals: Water budget-related dynamical phase space; Connect large-scale dynamical conditions to atmospheric water budget (including precipitation); Connect atmospheric water budget to cloud type distributions.

  10. Energy and helicity budgets of solar quiet regions

    CERN Document Server

    Tziotziou, K; Georgoulis, M K; Kontogiannis, I

    2014-01-01

    We investigate the free magnetic energy and relative magnetic helicity budgets of solar quiet regions. Using a novel non-linear force-free method requiring single solar vector magnetograms we calculate the instantaneous free magnetic energy and relative magnetic helicity budgets in 55 quiet-Sun vector magnetograms. As in a previous work on active regions, we construct here for the first time the (free) energy-(relative) helicity diagram of quiet-Sun regions. We find that quiet-Sun regions have no dominant sense of helicity and show monotonic correlations a) between free magnetic energy/relative helicity and magnetic network area and, consequently, b) between free magnetic energy and helicity. Free magnetic energy budgets of quiet-Sun regions represent a rather continuous extension of respective active-region budgets towards lower values, but the corresponding helicity transition is discontinuous due to the incoherence of the helicity sense contrary to active regions. We further estimate the instantaneous free...

  11. Budget Increases Proposed for NOAA and Energy Department

    Science.gov (United States)

    Showstack, Randy

    2009-05-01

    In addition to the Obama administration's proposed budget increases for NASA, the Environmental Protection Agency, and the U.S. Geological Survey (see Eos, 90(10), 83, 2009, and 90(20), 175, 2009), other federal Earth and space science agencies also would receive boosts in the proposed fiscal year (FY) 2010 budget. The proposed budget comes on top of the 2009 American Recovery and Reinvestment Act's (ARRA) US$18.3 billion in stimulus spending for research and development that can be apportioned between the FY 2009 and FY 2010 budgets. This news item focuses on the budget proposals for the National Oceanic and Atmospheric Administration (NOAA) and the Department of Energy (DOE). Next week, Eos will look at the budget proposal for the National Science Foundation.

  12. Carbon budgets and energy transition pathways

    NARCIS (Netherlands)

    Van Vuuren, Detlef P.; Van Soest, Heleen; Riahi, Keywan; Clarke, Leon; Krey, Volker; Kriegler, Elmar; Rogelj, Joeri; Schaeffer, Michiel; Tavoni, Massimo

    2016-01-01

    Scenarios from integrated assessment models can provide insights into how carbon budgets relate to other policy-relevant indicators by including information on how fast and by how much emissions can be reduced. Such indicators include the peak year of global emissions, the decarbonisation rate and t

  13. Carbon budgets and energy transition pathways

    NARCIS (Netherlands)

    Vuuren, Van Detlef P.; Soest, van Heleen; Riahi, Keywan; Clarke, Leon; Krey, Volker; Kriegler, Elmar; Rogelj, Joeri; Schaeffer, Michiel; Tavoni, Massimo

    2016-01-01

    Scenarios from integrated assessment models can provide insights into how carbon budgets relate to other policy-relevant indicators by including information on how fast and by how much emissions can be reduced. Such indicators include the peak year of global emissions, the decarbonisation rate an

  14. Uncertainty in Analyzed Water and Energy Budgets at Continental Scales

    Science.gov (United States)

    Bosilovich, Michael G.; Robertson, F. R.; Mocko, D.; Chen, J.

    2011-01-01

    Operational analyses and retrospective-analyses provide all the physical terms of mater and energy budgets, guided by the assimilation of atmospheric observations. However, there is significant reliance on the numerical models, and so, uncertainty in the budget terms is always present. Here, we use a recently developed data set consisting of a mix of 10 analyses (both operational and retrospective) to quantify the uncertainty of analyzed water and energy budget terms for GEWEX continental-scale regions, following the evaluation of Dr. John Roads using individual reanalyses data sets.

  15. A Stochastic Energy Budget Model Using Physically Based Red Noise

    CERN Document Server

    Weniger, Michael; Hense, Andreas

    2011-01-01

    A method to describe unresolved processes in meteorological models by physically based stochastic processes (SP) is proposed by the example of an energy budget model (EBM). Contrary to the common approach using additive white noise, a suitable variable within the model is chosen to be represented by a SP. Spectral analysis of ice core time series shows a red noise character of the underlying fluctuations. Fitting Ornstein Uhlenbeck processes to the observed spectrum defines the parameters for the stochastic dynamic model (SDM). Numerical simulations for different sets of ice core data lead to three sets of strongly differing systems. Pathwise, statistical and spectral analysis of these models show the importance of carefully choosing suitable stochastic terms in order to get a physically meaningful SDM.

  16. 10 CFR 434.502 - Determination of the annual energy cost budget.

    Science.gov (United States)

    2010-01-01

    ... Budgets. Each monthly Energy Cost Budget is the product of the monthly Building Energy Consumption of each... MULTI-FAMILY HIGH RISE RESIDENTIAL BUILDINGS Building Energy Cost Compliance Alternative § 434.502... Cost Budget BECONmi = The monthly Budget Energy Consumption of the ith type of energy ECOSmi =...

  17. Energy consumption in commercial buildings: A comparison with BEPS budgets

    Science.gov (United States)

    1980-09-01

    Metered energy consumption data were collected on existing commercial buildings to help establish the proposed building energy performance standards (BEPS). The search has identified 84 buildings whose metered energy consumption is equal to or less than that proposed for their BEPS budgets and another 7 buildings whose metered consumption is less than 20 percent above their BEPS budgets. The methodology used to identify the buildings and to collect their metered energy consumption data are described. The data are analyzed and summarized and conclusions are drawn.

  18. Budget of Turbulent Kinetic Energy in a Shock Wave Boundary-Layer Interaction

    Science.gov (United States)

    Vyas, Manan A.; Waindim, Mbu; Gaitonde, Datta V.

    2016-01-01

    Implicit large-eddy simulation (ILES) of a shock wave/boundary-layer interaction (SBLI) was performed. Quantities present in the exact equation of the turbulent kinetic energy transport were accumulated and used to calculate terms like production, dissipation, molecular diffusion, and turbulent transport. The present results for a turbulent boundary layer were validated by comparison with direct numerical simulation data. It was found that a longer development domain was necessary for the boundary layer to reach an equilibrium state and a finer mesh resolution would improve the predictions. In spite of these findings, trends of the present budget match closely with that of the direct numerical simulation. Budgets for the SBLI region are presented at key axial stations. These budgets showed interesting dynamics as the incoming boundary layer transforms and the terms of the turbulent kinetic energy budget change behavior within the interaction region.

  19. UV Diagnostics for the Energy Budget of Flares and CMEs

    Indian Academy of Sciences (India)

    J. C. Raymond

    2008-03-01

    Solar flares and coronal mass ejections convert large amounts of magnetic free energy into thermal, kinetic and potential energies, and into energy of non-thermal particles. The partitioning among these forms of energy is fundamental to both the physics of the eruptive events and the space weather consequences of the eruptions. This talk describes some aspects of the energy budget that can be derived from ultraviolet observations of the corona.

  20. Bark beetle-induced tree mortality alters stand energy budgets due to water budget changes

    Science.gov (United States)

    Reed, David E.; Ewers, Brent E.; Pendall, Elise; Frank, John; Kelly, Robert

    2016-10-01

    Insect outbreaks are major disturbances that affect a land area similar to that of forest fires across North America. The recent mountain pine bark beetle (D endroctonus ponderosae) outbreak and its associated blue stain fungi (Grosmannia clavigera) are impacting water partitioning processes of forests in the Rocky Mountain region as the spatially heterogeneous disturbance spreads across the landscape. Water cycling may dramatically change due to increasing spatial heterogeneity from uneven mortality. Water and energy storage within trees and soils may also decrease, due to hydraulic failure and mortality caused by blue stain fungi followed by shifts in the water budget. This forest disturbance was unique in comparison to fire or timber harvesting because water fluxes were altered before significant structural change occurred to the canopy. We investigated the impacts of bark beetles on lodgepole pine (Pinus contorta) stand and ecosystem level hydrologic processes and the resulting vertical and horizontal spatial variability in energy storage. Bark beetle-impacted stands had on average 57 % higher soil moisture, 1.5 °C higher soil temperature, and 0.8 °C higher tree bole temperature over four growing seasons compared to unimpacted stands. Seasonal latent heat flux was highly correlated with soil moisture. Thus, high mortality levels led to an increase in ecosystem level Bowen ratio as sensible heat fluxes increased yearly and latent heat fluxes varied with soil moisture levels. Decline in canopy biomass (leaf, stem, and branch) was not seen, but ground-to-atmosphere longwave radiation flux increased, as the ground surface was a larger component of the longwave radiation. Variability in soil, latent, and sensible heat flux and radiation measurements increased during the disturbance. Accounting for stand level variability in water and energy fluxes will provide a method to quantify potential drivers of ecosystem processes and services as well as lead to greater

  1. Recent Changes in Earth's Energy Budget As Observed By CERES

    Science.gov (United States)

    Loeb, N. G.

    2014-12-01

    A central objective of the Clouds and the Earth's Radiant Energy System (CERES) is to produce a long-term climate data record of Earth's radiation budget at the top-of-atmosphere, within-atmosphere and surface together with coincident cloud, aerosol and surface properties. CERES relies on a number of data sources, including broadband CERES radiometers on Terra, Aqua, and Suomi-NPP, high-resolution spectral imagers (MODIS and VIIRS), geostationary visible/infrared imagers, meteorological, aerosol and ozone assimilation data, and snow/sea-ice maps based on microwave radiometer data. The many input data sets are integrated and cross-calibrated to provide a consistent climate data record that accurately captures variations in Earth's radiation budget and associated cloud, aerosol and surface properties over a range of time and space scales. The CERES datasets are primarily used for climate model evaluation, process studies and climate monitoring. This presentation will review some of the ways in which the CERES record along with other datasets have been used to improve our understanding Earth's energy budget. At the top-of-atmosphere, we will show how Earth's energy imbalance, a critical indictor of climate change, has varied during the past 15 years relative to what is observed by in-situ observations of ocean heat content by the Argo observing system. We will use these results to place the so-called global warming hiatus into a larger context that takes Earth's energy budget into account. We will also discuss how recent advances in surface radiation budget estimation by the CERES group is reshaping the debate on why the surface energy budget cannot be closed to better than 15 Wm-2 using state-of-the-art observations. Finally, we will highlight the dramatic changes that have been observed by CERES over the Arctic Ocean, and discuss some of the yet unresolved observational challenges that limit our ability document change in this unique part of the planet.

  2. Properties of the kinetic energy budgets in wall-bounded turbulent flows

    Science.gov (United States)

    Zhou, Ang; Klewicki, Joseph

    2016-08-01

    Available high-quality numerical simulation data are used to investigate and characterize the kinetic energy budgets for fully developed turbulent flow in pipes and channels, and in the zero-pressure gradient turbulent boundary layer. The mean kinetic energy equation in these flows is empirically and analytically shown to respectively exhibit the same four-layer leading-order balance structure as the mean momentum equation. This property of the mean kinetic energy budget provides guidance on how to group terms in the more complicated turbulence and total kinetic energy budgets. Under the suggested grouping, the turbulence budget shows either a two- or three-layer structure (depending on channel or pipe versus boundary layer flow), while the total kinetic energy budget exhibits a clear four-layer structure. These layers, however, differ in position and size and exhibit variations with friction Reynolds number (δ+) that are distinct from the layer structure associated with the mean dynamics. The present analyses indicate that each of the four layers is characterized by a predominance of a reduced set of the grouped terms in the governing equation. The width of the third layer is mathematically reasoned to scale like δ+-√{δ+} at finite Reynolds numbers. In the boundary layer the upper bounds of both the second and third layers convincingly merge under this normalization, as does the width of the third layer. This normalization also seems to be valid for the width of the third layer in pipes and channels, but only for δ+>1000 . The leading-order balances in the total kinetic energy budget are shown to arise from a nontrivial interweaving of the mean and turbulence budget contributions with distance from the wall.

  3. Public Infrastructure Investment, Output Dynamics, and Balanced Budget Fiscal Rules

    NARCIS (Netherlands)

    Duarte Bom, P.R.; Ligthart, J.E.

    2011-01-01

    We study the dynamic output and welfare effects of public infrastructure investment under a balanced budget fiscal rule, using an overlapping generations model of a small open economy. The government finances public investment by employing distortionary labor taxes. We find a negative short-run outp

  4. Public Infrastructure Investment, Output Dynamics, and Balanced Budget Fiscal Rules

    NARCIS (Netherlands)

    Duarte Bom, P.R.; Ligthart, J.E.

    2011-01-01

    We study the dynamic output and welfare effects of public infrastructure investment under a balanced budget fiscal rule, using an overlapping generations model of a small open economy. The government finances public investment by employing distortionary labor taxes. We find a negative short-run

  5. United States Department of Energy Budget Highlights FY 1994

    Energy Technology Data Exchange (ETDEWEB)

    O`Leary, H.R.

    1993-04-01

    The President`s Fiscal Year 1994 budget request for the Department of Energy reflects the Administration`s goal of redressing the balance between the Nation`s energy and economic requirements and protection of the environment. The Department plans to undertake a careful restructuring of its national defense responsibilities, in line with post Cold War exigencies; contribute to the Administration`s deficit reduction objectives; and fulfill the President`s commitment to invest in science and technology development and transfer.

  6. Wave energy budget analysis in the Earth's radiation belts uncovers a missing energy

    National Research Council Canada - National Science Library

    Artemyev, A V; Agapitov, O V; Mourenas, D; Krasnoselskikh, V V; Mozer, F S

    2015-01-01

    .... Here, we report an analysis of 10-year Cluster data, statistically evaluating the full wave energy budget in the Earth's magnetosphere, revealing that a significant fraction of the energy corresponds...

  7. The energy budget of stellar magnetic fields

    Science.gov (United States)

    See, V.; Jardine, M.; Vidotto, A. A.; Donati, J.-F.; Folsom, C. P.; Boro Saikia, S.; Bouvier, J.; Fares, R.; Gregory, S. G.; Hussain, G.; Jeffers, S. V.; Marsden, S. C.; Morin, J.; Moutou, C.; do Nascimento, J. D.; Petit, P.; Rosén, L.; Waite, I. A.

    2015-11-01

    Spectropolarimetric observations have been used to map stellar magnetic fields, many of which display strong bands of azimuthal fields that are toroidal. A number of explanations have been proposed to explain how such fields might be generated though none are definitive. In this paper, we examine the toroidal fields of a sample of 55 stars with magnetic maps, with masses in the range 0.1-1.5 M⊙. We find that the energy contained in toroidal fields has a power-law dependence on the energy contained in poloidal fields. However the power index is not constant across our sample, with stars less and more massive than 0.5 M⊙ having power indices of 0.72 ± 0.08 and 1.25 ± 0.06, respectively. There is some evidence that these two power laws correspond to stars in the saturated and unsaturated regimes of the rotation-activity relation. Additionally, our sample shows that strong toroidal fields must be generated axisymmetrically. The latitudes at which these bands appear depend on the stellar rotation period with fast rotators displaying higher latitude bands than slow rotators. The results in this paper present new constraints for future dynamo studies.

  8. The energy budget of stellar magnetic fields

    CERN Document Server

    See, V; Vidotto, A A; Donati, J -F; Folsom, C P; Saikia, S Boro; Bouvier, J; Fares, R; Gregory, S G; Hussain, G; Jeffers, S V; Marsden, S C; Morin, J; Moutou, C; Nascimento, J D do; Petit, P; Rosen, L; Waite, I A

    2015-01-01

    Spectropolarimetric observations have been used to map stellar magnetic fields, many of which display strong bands of azimuthal fields that are toroidal. A number of explanations have been proposed to explain how such fields might be generated though none are definitive. In this paper, we examine the toroidal fields of a sample of 55 stars with magnetic maps, with masses in the range 0.1-1.5$\\,{\\rm M}_\\odot$. We find that the energy contained in toroidal fields has a power law dependence on the energy contained in poloidal fields. However the power index is not constant across our sample, with stars less and more massive than 0.5$\\,{\\rm M}_\\odot$ having power indices of 0.72$\\pm$0.08 and 1.25$\\pm$0.06 respectively. There is some evidence that these two power laws correspond to stars in the saturated and unsaturated regimes of the rotation-activity relation. Additionally, our sample shows that strong toroidal fields must be generated axisymmetrically. The latitudes at which these bands appear depend on the ste...

  9. Sub-Facet Heterogeneity of the Urban Surface Energy Budget

    Science.gov (United States)

    Ramamurthy, P.; Bou-Zeid, E.; Smith, J. A.; Baeck, M. L.; Welty, C.

    2013-12-01

    The Princeton Urban Canopy Model (PUCM) and observational data are combined to understand the influence of urban sub-facet heterogeneity, and the associated influence of material properties, on the urban surface energy budget. This heterogeneity is related to the different surfaces and materials (asphalt, concrete, grass, black roofs, green roofs, etc.) that are typically found within one urban facet (roof, wall, and ground). Of particular interest is the role of water storage and evaporation from urban surfaces in modulating the energy budget. The PUCM is evaluated at sites of various urban densities. Subsequently, one densely-built site is selected for in-depth analysis and the model is applied, with sub-facet resolution, to simulate the water and energy budgets. Our analyses show that while all built surfaces convert most of the incoming energy into sensible rather than latent heat, sensible heat fluxes from asphalt and non-reflective rooftops are twice as high as those from concrete surfaces and light colored roofs. Another important and commonly observed characteristic of urban areas- the shift in peak time of sensible heat compared to rural areas, is shown to be mainly linked to concrete's high heat storage capacity. Our results also indicate that while evaporation from built surfaces is discontinuous and intermittent, overall, these surfaces accounted for nearly 16% of latent heat fluxes (LE) at the study site during the study period. More importantly, this contribution is mainly concentrated during the 48 hours following a rain event and thus its accurate representation is critical to our understanding of the urban surface energy budget during wet periods.

  10. The Energy Budget of the Polar Atmosphere in MERRA

    Science.gov (United States)

    Cullather, Richard I.; Bosilovich, Michael G.

    2010-01-01

    Components of the atmospheric energy budget from the Modern Era Retrospective-analysis for Research and Applications (MERRA) are evaluated in polar regions for the period 1979-2005 and compared with previous estimates, in situ observations, and contemporary reanalyses. Closure of the energy budget is reflected by the analysis increments term, which results from virtual enthalpy and latent heating contributions and averages -11 W/sq m over the north polar cap and -22 W/sq m over the south polar cap. Total energy tendency and energy convergence terms from MERRA agree closely with previous study for northern high latitudes but convergence exceeds previous estimates for the south polar cap by 46 percent. Discrepancies with the Southern Hemisphere transport are largest in autumn and may be related to differences in topography with earlier reanalyses. For the Arctic, differences between MERRA and other sources in TOA and surface radiative fluxes maximize in May. These differences are concurrent with the largest discrepancies between MERRA parameterized and observed surface albedo. For May, in situ observations of the upwelling shortwave flux in the Arctic are 80 W/sq m larger than MERRA, while the MERRA downwelling longwave flux is underestimated by 12 W/sq m throughout the year. Over grounded ice sheets, the annual mean net surface energy flux in MERRA is erroneously non-zero. Contemporary reanalyses from the Climate Forecast Center (CFSR) and the Interim Re-Analyses of the European Centre for Medium Range Weather Forecasts (ERA-I) are found to have better surface parameterizations, however these collections are also found to have significant discrepancies with observed surface and TOA energy fluxes. Discrepancies among available reanalyses underscore the challenge of reproducing credible estimates of the atmospheric energy budget in polar regions.

  11. Energy Budgets of the Giant Planets and Titan

    Science.gov (United States)

    Liming, Li; Smith, Mark A.; Conrath, Barney J.; Conrath, Peter J.; Simon-Miller, Amy A.; Baines, Kevin H.; West, Robert A.; Achterberg, Richard K.; Orton, Glenn S.; Santiago, Perez-Hoyos; hide

    2012-01-01

    As a fundamental property, the energy budget affects many aspeCts of planets and their moons, such as thermal structure, meteorology, and evolution. We use the observations from two Cassini spectrometers (i.e., CIRS and VIMS) to explore one important component of the energy budget the total emitted power of Jupiter, Saturn, and Titan (Li et al., 2010, 2011, 2012). Key results are: (1) The Cassini observations precisely measure the global-average emitted power of three bodies: 14.l0+/-0.03 Wm(exp -2), 4.952+/-0.035 Wm(exp -2), and 2.834+/-0.012 Wm(exp -2) for Jupiter, Saturn, and Titan, respectively. (2) The meridional distribution of emitted power displays a significant asymmetry between the northern and southern hemispheres on Jupiter and Saturn. On Titan, the meridional distribution of emitted power is basically symmetric around the equator. (3) Comparing with the Voyager measurements, the new Cassini observations reveal a significant temporal variation of emitted power on both Jupiter and Saturn: i) The asymmetry between the two hemisphere shown in the Cassini epoch (2000-2010) is not present in the Voyager epoch (1979-1980); and ii) From the Voyager epoch to the Cassini epoch, the global-average emitted power appeared to increase by approx 3.8% for Jupiter and approx 6.4% for Saturn. (4) Together with previous measurements of the absorbed solar power on Titan, the new Cassini measurements of emitted power provide the first observational evidence of the global energy balance on Titan. The uncertainty in the previous measurements of absorbed solar energy places an upper limit on its energy imbalance of 6.0% on Titan. The exploration of emitted power is the first part of a series of studies examining the temporal variability of the energy budget on the giant planets and Titan. Currently, We are measuring the absorbed solar energy in order to determine new constraints on the energy budgets of Jupiter, Saturn, and Titan.

  12. Budgets of divergent and rotational kinetic energy during two periods of intense convection

    Science.gov (United States)

    Buechler, D. E.; Fuelberg, H. E.

    1986-01-01

    The derivations of the energy budget equations for divergent and rotational components of kinetic energy are provided. The intense convection periods studied are: (1) synoptic scale data of 3 or 6 hour intervals and (2) mesoalphascale data every 3 hours. Composite energies and averaged budgets for the periods are presented; the effects of random data errors on derived energy parameters is investigated. The divergent kinetic energy and rotational kinetic energy budgets are compared; good correlation of the data is observed. The kinetic energies and budget terms increase with convective development; however, the conversion of the divergent and rotational energies are opposite.

  13. A multi-layer land surface energy budget model for implicit coupling with global atmospheric simulations

    Directory of Open Access Journals (Sweden)

    J. Ryder

    2014-12-01

    Full Text Available In Earth system modelling, a description of the energy budget of the vegetated surface layer is fundamental as it determines the meteorological conditions in the planetary boundary layer and as such contributes to the atmospheric conditions and its circulation. The energy budget in most Earth system models has long been based on a "big-leaf approach", with averaging schemes that represent in-canopy processes. Such models have difficulties in reproducing consistently the energy balance in field observations. We here outline a newly developed numerical model for energy budget simulation, as a component of the land surface model ORCHIDEE-CAN (Organising Carbon and Hydrology In Dynamic Ecosystems – CANopy. This new model implements techniques from single-site canopy models in a practical way. It includes representation of in-canopy transport, a multilayer longwave radiation budget, height-specific calculation of aerodynamic and stomatal conductance, and interaction with the bare soil flux within the canopy space. Significantly, it avoids iterations over the height of tha canopy and so maintains implicit coupling to the atmospheric model LMDz. As a first test, the model is evaluated against data from both an intensive measurement campaign and longer term eddy covariance measurements for the intensively studied Eucalyptus stand at Tumbarumba, Australia. The model performs well in replicating both diurnal and annual cycles of fluxes, as well as the gradients of sensible heat fluxes. However, the model overestimates sensible heat flux against an underestimate of the radiation budget. Improved performance is expected through the implementation of a more detailed calculation of stand albedo and a more up-to-date stomatal conductance calculation.

  14. Dynamic phosphorus budget for lake-watershed ecosystems

    Institute of Scientific and Technical Information of China (English)

    LIU Yong; GUO Huai-cheng; WANG Li-jing; DAI Yong-li; ZHANG Xiu-min; LI Zi-hai; HE Bin

    2006-01-01

    Lake eutrophication caused by excess phosphorus (P) loading from point sources (PS) and nonpoint sources (NPS) is a persistent and serious ecological problem in China. A phosphorus budget, based on material flow analysis(MFA) and system dynamic(SD), is proposed and applied for the agriculture-dominated Qionghai Lake watershed located in southwestern China. The MFA-SD approach will not only cover the transporting process of P in the lake-watershed ecosystems, but also can deal with the changes of P budget due to the dynamics of watershed. P inflows include the fertilizer for agricultural croplands, soil losses, domestic sewage discharges, and the atmospheric disposition such as precipitation and dust sinking. Outflows are consisted of hydrologic export, water resources development, fishery and aquatic plants harvesting. The internal P recycling processes are also considered in this paper.From 1988 to 2015, the total P inflows for Lake Qionghai are in a rapid increase from 35.65 to 78.73 t/a, which results in the rising of P concentration in the lake. Among the total P load 2015, agricultural loss and domestic sewage account for 70.60% and 17.27%respectively, directly related to the rapid social-economic development and the swift urbanization. Future management programs designed to reduce P inputs must be put into practices in the coming years to ensure the ecosystem health in the watershed.

  15. 基于生物质能的芒属(Miscanthus)植物碳动态和收支研究进展%A review on carbon dynamics and budget of biomass energy species of Miscanthus spp.

    Institute of Scientific and Technical Information of China (English)

    欧阳旭; 张亚茹; 李跃林

    2013-01-01

    Miscanthus in European countries as a strategy to relieve the energy crisis and greenhouse effects, study in our country is still at a primary stage. The traditional agricultural use mode in China decided that researchers tended to pay more attention on grassland in northern China than that in southern China. Previous studies on grassland in south China focused on ecological restoration, seldom works were about the CO2 exchange capacity at the ecosystem level. However, with the continuing increase in carbon dioxide and its effects on global warming, researches on biomass plant and its carbon sink function become more and more important. Nearly 6.7×107 ha of degraded grassland in mountain areas in southern China are urgent to be restored or in the process of restoration. Miscanthus grasslands have a low demand for nutrient inputs, they may also be produced with little or no pesticide use, and make full use of natural resources such as light and water, and they have high water use and nutrient use efficiency, which make it reach the biomass plant criteria. Compared to other biomass sources, C4 plants outyield C3 plant due to their more efficient photosynthetic pathway. It is worthy to notice that C4 Miscanthus grasses have great carbon sequestration capacity and potential energy in the biomass with high light use efficiency. Hence, a full assessment of carbon dynamics and budgets for Miscanthus grasses are needed. This paper reviewed the current situation of researches on Miscanthus biomass at home and abroad, and concentrated on studies of carbon dynamics and budgets of biomass energy in Miscanthus grasses at ecosystem level. More objective assessment methods of Miscanthus carbon sequestration function at the ecosystem were discussed. Meanwhile, based on the studies of biomass process, research history and current situation of grass land in south China, it was illustrated that the rational exploitation and utilization of biomass energy resources in degraded grasslands brings

  16. Relative Efficiency of Surface Energy Budgets Over Different Land Covers

    Science.gov (United States)

    Yang, Jiachuan

    The partitioning of available solar energy into different fluxes at the Earth's surface is important in determining different physical processes, such as turbulent transport, subsurface hydrology, land-atmospheric interactions, etc. Direct measurements of these turbulent fluxes were carried out using eddy-covariance (EC) towers. However, the distribution of EC towers is sparse due to relatively high cost and practical difficulties in logistics and deployment. As a result, data is temporally and spatially limited and is inadequate to be used for researches at large scales, such as regional and global climate modeling. Besides field measurements, an alternative way is to estimate turbulent fluxes based on the intrinsic relations between surface energy budget components, largely through thermodynamic equilibrium. These relations, referred as relative efficiency, have been included in several models to estimate the magnitude of turbulent fluxes in surface energy budgets such as latent heat and sensible heat. In this study, three theoretical models based on the lumped heat transfer model, the linear stability analysis and the maximum entropy principle respectively, were investigated. Model predictions of relative efficiencies were compared with turbulent flux data over different land covers, viz. lake, grassland and suburban surfaces. Similar results were observed over lake and suburban surface but significant deviation is found over vegetation surface. The relative efficiency of outgoing longwave radiation is found to be orders of magnitude deviated from theoretic predictions. Meanwhile, results show that energy partitioning process is influenced by the surface water availability to a great extent. The study provides insight into what property is determining energy partitioning process over different land covers and gives suggestion for future models.

  17. The eddy kinetic energy budget in the Red Sea

    KAUST Repository

    Zhan, Peng

    2016-06-09

    The budget of eddy kinetic energy (EKE) in the Red Sea, including the sources, redistributions and sink, is examined using a high-resolution eddy-resolving ocean circulation model. A pronounced seasonally varying EKE is identified, with its maximum intensity occurring in winter, and the strongest EKE is captured mainly in the central and northern basins within the upper 200 m. Eddies acquire kinetic energy from conversion of eddy available potential energy (EPE), from transfer of mean kinetic energy (MKE), and from direct generation due to time-varying (turbulent) wind stress, the first of which contributes predominantly to the majority of the EKE. The EPE-to-EKE conversion occurs almost in the entire basin, while the MKE-to-EKE transfer appears mainly along the shelf boundary of the basin (200 miso-bath) where high horizontal shear interacts with topography. The EKE generated by the turbulent wind stress is relatively small and limited to the southern basin. All these processes are intensified during winter, when the rate of energy conversion is about four to five times larger than that in summer. The EKE is redistributed by the vertical and horizontal divergence of energy flux and the advection of the mean flow. As a main sink of EKE, dissipation processes is ubiquitously found in the basin. The seasonal variability of these energy conversion terms can explain the significant seasonality of eddy activities in the Red Sea. This article is protected by copyright. All rights reserved.

  18. The eddy kinetic energy budget in the Red Sea

    Science.gov (United States)

    Zhan, Peng; Subramanian, Aneesh C.; Yao, Fengchao; Kartadikaria, Aditya R.; Guo, Daquan; Hoteit, Ibrahim

    2016-07-01

    The budget of eddy kinetic energy (EKE) in the Red Sea, including the sources, redistributions, and sink, is examined using a high'resolution eddy-resolving ocean circulation model. A pronounced seasonally varying EKE is identified, with its maximum intensity occurring in winter, and the strongest EKE is captured mainly in the central and northern basins within the upper 200 m. Eddies acquire kinetic energy from conversion of eddy available potential energy (EPE), from transfer of mean kinetic energy (MKE), and from direct generation due to time-varying (turbulent) wind stress, the first of which contributes predominantly to the majority of the EKE. The EPE-to-EKE conversion occurs almost in the entire basin, while the MKE-to-EKE transfer appears mainly along the shelf boundary of the basin (200 m isobath) where high horizontal shear interacts with topography. The EKE generated by the turbulent wind stress is relatively small and limited to the southern basin. All these processes are intensified during winter, when the rate of energy conversion is about 4-5 times larger than that in summer. The EKE is redistributed by the vertical and horizontal divergence of energy flux and the advection of the mean flow. As a main sink of EKE, dissipation processes is ubiquitously found in the basin. The seasonal variability of these energy conversion terms can explain the significant seasonality of eddy activities in the Red Sea.

  19. 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

  20. The kinetic and available potential energy budget of a winter extratropical cyclone system

    Science.gov (United States)

    Smith, P. J.; Dare, P. M.

    1986-01-01

    The energy budget of an extratropical cyclone system which traversed North America and intensified through the period January 9-11, 1975 is presented. The objectives of the study are: (1) to document the complete energy budget of a significant winter cyclone event, and (2) to comment on the significance of latent heat release (LHR) in the cyclone's evolution. Results reveal an overall increase in both kinetic (K) and available potential energy (A). K increases are accounted for by boundary flux convergence of K, while A increases are due to generation by LHR and K to A conversion. In addition, the general A increase is accompanied by a 24 h oscillation that is explained largely by the flux quantity in the A budget equation and is correlated with a similar fluctuation in the K to A conversion. LHR does not appear to be critical in the development of this cyclone system. Rather, LHR acts to increase the intensity of the event. It is hypothesized that the direct influence that LHR had on the deepening cyclone's reduced mass was augmented by an indirect influence, in which pre-existing dry dynamical forcing was enhanced by diabatic heating, thus leading to accelerated cyclone development at a later time.

  1. The kinetic and available potential energy budget of a winter extratropical cyclone system

    Science.gov (United States)

    Smith, P. J.; Dare, P. M.

    1986-01-01

    The energy budget of an extratropical cyclone system which traversed North America and intensified through the period January 9-11, 1975 is presented. The objectives of the study are: (1) to document the complete energy budget of a significant winter cyclone event, and (2) to comment on the significance of latent heat release (LHR) in the cyclone's evolution. Results reveal an overall increase in both kinetic (K) and available potential energy (A). K increases are accounted for by boundary flux convergence of K, while A increases are due to generation by LHR and K to A conversion. In addition, the general A increase is accompanied by a 24 h oscillation that is explained largely by the flux quantity in the A budget equation and is correlated with a similar fluctuation in the K to A conversion. LHR does not appear to be critical in the development of this cyclone system. Rather, LHR acts to increase the intensity of the event. It is hypothesized that the direct influence that LHR had on the deepening cyclone's reduced mass was augmented by an indirect influence, in which pre-existing dry dynamical forcing was enhanced by diabatic heating, thus leading to accelerated cyclone development at a later time.

  2. Mass and energy budgets of animals: Behavioral and ecological implications

    Energy Technology Data Exchange (ETDEWEB)

    Porter, W.P.

    1993-01-01

    The common goal of these diverse projects is to understand the mechanisms of how animal populations respond to the continual changes in their environment in both time and space. Our models are mechanistic allowing us to explore how a wide array of environmental variables may determine individual performance. Large scale climate change and its effect on animal populations can be seen as quantitative extensions of biological responses to smaller scales of environmental variability. Changes in developmental rates or reproductive levels of individuals, extension or contraction of geographic ranges, and modification of community organization have all been documented in response to previous changes in habitats. We know from our biophysical work that some changes in function are driven by microclimate conditions directly, and some are mediated indirectly through ecological parameters such as the food supply. Our research is guided by a comprehensive conceptual scheme of the interaction of an animal with its environment. The physical and physiological properties of the organism, and the range of available microclimates, set bounds on the performance of organismal function, such as growth, reproduction, storage, and behavior. To leave the most offspring over a lifetime, animals must perform those functions in a way that maximizes the amount of resources devoted to reproduction. Maximizing the total size of the budget and minimizing those budget items not devoted to reproduction are crucial. Animals trade off among expenditures for current and future reproduction. Both water and energy are important, potentially limiting resources. Projects described here include empirical studies and theoretical models.

  3. Growth and the energy budget of flat oyster (Ostrea edulis in early ontogenesis

    Directory of Open Access Journals (Sweden)

    N. A. Sitnik

    2010-09-01

    Full Text Available Regularities of growth and dynamics of balance constituents of the energy budget of the flat oyster larvae in development are investigated. It is shown, that the linear growth in early ontogenesis is described by the exponential equation with high accuracy. Parameters of the functions connecting length, height and weight of larvae are defined. The quantitative characteristic of the energy balance elements of oysters larvae is given. It is shown, that during development from a veliger stage to a pediveliger the energy expenditures for growth, metabolism and nutriment assimilation increase more than 10 times. Net efficiency of larvae growth (coefficient К2 varies within 61.6–62.8 % during development, and the magnitude of a specific daily ration of oyster larvae equals 32–35 % of the energy equivalent of body weight.

  4. Cell energy budget platform for assessment of cell metabolism.

    Science.gov (United States)

    Papkovsky, Dmitri B; Zhdanov, Alexander V

    2015-01-01

    Changes in bioenergetic parameters report on metabolic rearrangement, dysfunction of major pathways, and regulatory processes within the cell, adaptation to energy stress, or new physiological condition. A combined measurement of oxidative phosphorylation, glycolytic flux, the Krebs cycle activity, ATP levels, and total biomass allows detailed metabolic assessment. We describe a simple methodology for high-throughput multiparametric assessment of cell bioenergetics, called cell energy budget (CEB) platform, and demonstrate its practical use with cell models. The CEB relies on a standard multi-label reader with time-resolved fluorescence capabilities, the lanthanide probe pH-Xtra™ to measure extracellular acidification (ECA) associated with lactate (L-ECA) and combined lactate/CO2 (T-ECA) extrusion, the phosphorescent probe MitoXpress®-Xtra to measure oxygen consumption rate (OCR), the bioluminescent total ATP assay, and absorbance-based total protein assay. This approach can be further extended with the measurement of other cellular parameters, such as NAD(P)H, Ca(2+), mitochondrial pH, membrane potential, and redox state, using the corresponding fluorescent or luminescent probes.

  5. Practice Prize Winner --Dynamic Marketing Budget Allocation Across Countries, Products, and Marketing Activities

    OpenAIRE

    Marc Fischer; Sönke Albers; Nils Wagner; Monika Frie

    2011-01-01

    Previous research on marketing budget decisions has shown that profit improvement from better allocation across products or regions is much higher than from improving the overall budget. However, despite its high managerial relevance, contributions by marketing scholars are rare. In this paper, we introduce an innovative and feasible solution to the dynamic marketing budget allocation problem for multiproduct, multicountry firms. Specifically, our decision support model allows determining nea...

  6. Impact of decadal cloud variations on the Earth's energy budget

    Science.gov (United States)

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

    2016-12-01

    Feedbacks of clouds on climate change strongly influence the magnitude of global warming. Cloud feedbacks, in turn, depend on the spatial patterns of surface warming, which vary on decadal timescales. Therefore, the magnitude of the decadal cloud feedback could deviate from the long-term cloud feedback. Here we present climate model simulations to show that the global mean cloud feedback in response to decadal temperature fluctuations varies dramatically due to time variations in the spatial pattern of sea surface temperature. We find that cloud anomalies associated with these patterns significantly modify the Earth's energy budget. Specifically, the decadal cloud feedback between the 1980s and 2000s is substantially more negative than the long-term cloud feedback. This is a result of cooling in tropical regions where air descends, relative to warming in tropical ascent regions, which strengthens low-level atmospheric stability. Under these conditions, low-level cloud cover and its reflection of solar radiation increase, despite an increase in global mean surface temperature. These results suggest that sea surface temperature pattern-induced low cloud anomalies could have contributed to the period of reduced warming between 1998 and 2013, and offer a physical explanation of why climate sensitivities estimated from recently observed trends are probably biased low.

  7. Energy Budget of the Thermosphere and Mesosphere from 15 Years of SABER Observations

    Science.gov (United States)

    Hunt, L. A.; Mlynczak, M. G.; Marshall, B. T.; Russell, J. M., III

    2016-12-01

    The Sounding of the Atmosphere using Broadband Emission Radiometry (SABER) instrument on the Thermosphere-Ionosphere-Mesosphere Energetics and Dynamics (TIMED) satellite has provided nearly 15 years of continuous measurements in the mesosphere and thermosphere and operations are ongoing. The SABER instrument has performed exceptionally well since its launch in December 2001, and several more years of observations are eagerly anticipated. SABER is a limb-scanning instrument that makes vertical profile measurements of infrared radiance in ten channels chosen to permit retrieval or derivation of a variety of data products. These include radiative emission of NO at 5.3 μm and CO2 at 15 μm, two key components that govern radiative cooling of the atmosphere above 100 km. Other channels provide information about the thermal structure and elements of the energy budget of the upper mesosphere. From SABER radiances, we determine amounts of atomic oxygen and hydrogen, radiative cooling by CO2, solar heating by O3 and O2, and chemical heating from a suite of exothermic reactions over the vertical range of 65-100 km. We have observed changes in the energy budgets of these regions from mid-solar cycle 23 to the current downturn in solar cycle 24, encompassing portions of two very different solar cycles and the unusually long solar minimum between them. This talk focuses on the natural variability in the composition and energy budget of the mesosphere and lower thermosphere imposed by the variability of the Sun over the past 15 years.

  8. How subsurface patterns affect surface energy budget patterns: a sudanian case study

    Science.gov (United States)

    Robert, D.; Cohard, J.; Descloitres, M.; Vandervaere, J.; Braud, I.; Vauclin, M.

    2011-12-01

    Fractured bedrock areas are still challenging for hydrological modeling because of their complex underground property distributions. The heterogeneity in soil hydraulic properties, for example, can control the subsurface water fluxes and create surface soil moisture pattern which becomes preferential areas for runoff production or evapotranspiration. This study aimed to evaluate the impact of a bedrock topography, including outcropping, on subsurface water fluxes and the induced energy budget patterns at the surface. To deal with these ground water/surface water interactions, we run the Parflow-CLM distributed coupled land surface and groundwater model over the 12km2 Ara watershed (Northern Benin) for different bedrock configurations. The Ara catchment is submitted to a sudanian climate with 1200mm total rainfall per year. It is part of the AMMA-Catch project in which 3 meso sites have been documented along a south to north transect in West Africa. The geology of the Ara catchment is composed of metamorphic rocks. The main orientation of the geological structures (and of the gneiss foliation) is roughly north-south and the dip angle is 20° east. These structure create patterns in effective porosity distribution which is supposed to induce subsurface flow perpendicular to surface slope direction. Controlled Parflow-CLM simulation results are compared with energy budget data, including 3 net radiation measurements, eddy covariance station, scintillometric measurements to estimate evapotranspiration at different scales. The experimental device also include ground measurements like distributed surface soil moisture profile and piezometers. Parflow-CLM simulations are in good agreement with energy budget observations if observed Leaf Area Index time series are take into account. Then different hydraulic property distributions (effective porosity, hydraulic transmissivity, water retention curves) are evaluated through watershed dynamic differences.

  9. Surface energy budget responses to radiative forcing at Summit, Greenland

    Science.gov (United States)

    Miller, Nathaniel B.; Shupe, Matthew D.; Cox, Christopher J.; Noone, David; Persson, P. Ola G.; Steffen, Konrad

    2017-02-01

    Greenland Ice Sheet surface temperatures are controlled by an exchange of energy at the surface, which includes radiative, turbulent, and ground heat fluxes. Data collected by multiple projects are leveraged to calculate all surface energy budget (SEB) terms at Summit, Greenland, for the full annual cycle from July 2013 to June 2014 and extend to longer periods for the radiative and turbulent SEB terms. Radiative fluxes are measured directly by a suite of broadband radiometers. Turbulent sensible heat flux is estimated via the bulk aerodynamic and eddy correlation methods, and the turbulent latent heat flux is calculated via a two-level approach using measurements at 10 and 2 m. The subsurface heat flux is calculated using a string of thermistors buried in the snow pack. Extensive quality-control data processing produced a data set in which all terms of the SEB are present 75 % of the full annual cycle, despite the harsh conditions. By including a storage term for a near-surface layer, the SEB is balanced in this data set to within the aggregated uncertainties for the individual terms. November and August case studies illustrate that surface radiative forcing is driven by synoptically forced cloud characteristics, especially by low-level, liquid-bearing clouds. The annual cycle and seasonal diurnal cycles of all SEB components indicate that the non-radiative terms are anticorrelated to changes in the total radiative flux and are hence responding to cloud radiative forcing. Generally, the non-radiative SEB terms and the upwelling longwave radiation component compensate for changes in downwelling radiation, although exact partitioning of energy in the response terms varies with season and near-surface characteristics such as stability and moisture availability. Substantial surface warming from low-level clouds typically leads to a change from a very stable to a weakly stable near-surface regime with no solar radiation or from a weakly stable to neutral

  10. The kinetic and available potential energy budget of a winter extratropical cyclone system

    OpenAIRE

    SMITH, PHILLIP J.; DARE, PATRICIA M.

    2011-01-01

    The energy budget of an extratropical cyclone system which traversed North America and intensified through the period 9–11 January 1975 is presented. The objectives of the study are (1) to document the complete energy budget of a significant winter cyclone event, and (2) to comment on the significance of latent heat release (LHR) in the cyclone's evolution. Results reveal an overall increase in both kinetic (K) and available potential energy (A). K increases are accounted for by boundary flux...

  11. Energy methods in dynamics

    CERN Document Server

    Le, Khanh Chau

    2014-01-01

    Energy Methods in Dynamics is a textbook based on the lectures given by the first author at Ruhr University Bochum, Germany. Its aim is to help students acquire both a good grasp of the first principles from which the governing equations can be derived, and the adequate mathematical methods for their solving. Its distinctive features, as seen from the title, lie in the systematic and intensive use of Hamilton's variational principle and its generalizations for deriving the governing equations of conservative and dissipative mechanical systems, and also in providing the direct variational-asymptotic analysis, whenever available, of the energy and dissipation for the solution of these equations. It demonstrates that many well-known methods in dynamics like those of Lindstedt-Poincare, Bogoliubov-Mitropolsky, Kolmogorov-Arnold-Moser (KAM), Wentzel–Kramers–Brillouin (WKB),  and Whitham are derivable from this variational-asymptotic analysis.   This second edition includes the solutions to all exercises as w...

  12. Wave energy budget analysis in the Earth's radiation belts uncovers a missing energy.

    Science.gov (United States)

    Artemyev, A V; Agapitov, O V; Mourenas, D; Krasnoselskikh, V V; Mozer, F S

    2015-05-15

    Whistler-mode emissions are important electromagnetic waves pervasive in the Earth's magnetosphere, where they continuously remove or energize electrons trapped by the geomagnetic field, controlling radiation hazards to satellites and astronauts and the upper-atmosphere ionization or chemical composition. Here, we report an analysis of 10-year Cluster data, statistically evaluating the full wave energy budget in the Earth's magnetosphere, revealing that a significant fraction of the energy corresponds to hitherto generally neglected very oblique waves. Such waves, with 10 times smaller magnetic power than parallel waves, typically have similar total energy. Moreover, they carry up to 80% of the wave energy involved in wave-particle resonant interactions. It implies that electron heating and precipitation into the atmosphere may have been significantly under/over-valued in past studies considering only conventional quasi-parallel waves. Very oblique waves may turn out to be a crucial agent of energy redistribution in the Earth's radiation belts, controlled by solar activity.

  13. The energy budget under the influence of topography in the Zhujiang River Estuary in China

    Institute of Scientific and Technical Information of China (English)

    LIU Huan; WU Chaoyu; WU Yaju

    2015-01-01

    The Zhujiang River (Pearl River) Estuary (ZRE) is a very complicated and large-scale estuarine system in China. It consists of two parts: the river networks and the estuarine bays. Not only is the network system one of the most complicated in the world, but also each estuarine bay has a very special morphodynamic feature due to the geological settings. Morphological boundary conditions have direct effects on the energy dissipa-tion and balance. On the basis of a three-dimensional (3-D) barotropic model whose domain includes the river networks and the estuarine bays, the energy budget is discussed under the influence of topography in the ZRE. The elevation and discharge of this model are validated by the observations collected in July 1999 and February 2001. The results show that (1) the source of energy in the ZRE is mainly generated by tides and river runoffs, which have an obvious seasonal change, and (2) there are some typical hotspots where the energy dissipation is 1–2 orders higher than those in the immediate upstream and downstream sections in the ZRE. These hotspots are linked with the small-scale dynamic structures (SSDS) and morphological units. On the basis of the characteristics of the morphology and the energy dissipation, the hotspots can be catego-rized into three types: the outlet of the ZRE, the meandering river, the branch and junction.

  14. Large-scale dynamical influence of a gravity wave generated over the Antarctic Peninsula – regional modelling and budget analysis

    Directory of Open Access Journals (Sweden)

    JOEL Arnault

    2013-03-01

    Full Text Available The case study of a mountain wave triggered by the Antarctic Peninsula on 6 October 2005, which has already been documented in the literature, is chosen here to quantify the associated gravity wave forcing on the large-scale flow, with a budget analysis of the horizontal wind components and horizontal kinetic energy. In particular, a numerical simulation using the Weather Research and Forecasting (WRF model is compared to a control simulation with flat orography to separate the contribution of the mountain wave from that of other synoptic processes of non-orographic origin. The so-called differential budgets of horizontal wind components and horizontal kinetic energy (after subtracting the results from the simulation without orography are then averaged horizontally and vertically in the inner domain of the simulation to quantify the mountain wave dynamical influence at this scale. This allows for a quantitative analysis of the simulated mountain wave's dynamical influence, including the orographically induced pressure drag, the counterbalancing wave-induced vertical transport of momentum from the flow aloft, the momentum and energy exchanges with the outer flow at the lateral and upper boundaries, the effect of turbulent mixing, the dynamics associated with geostrophic re-adjustment of the inner flow, the deceleration of the inner flow, the secondary generation of an inertia–gravity wave and the so-called baroclinic conversion of energy between potential energy and kinetic energy.

  15. Energy Budget on Various Land Use Areas Using Reanalysis Data in Florida

    Directory of Open Access Journals (Sweden)

    Chi-Han Cheng

    2014-01-01

    Full Text Available Energy budget is closely related to the hydrological cycle through evapotranspiration (ET or latent heat. Hence, quantifying the energy budget on different land uses is critical for understanding the water budget and providing useful land use information for decision makers. However, traditional methods, including in situ measurements and model-only approaches, have deficiencies in data availability, and we have still not yet fully realized how well the energy budgets presented in reanalysis data sets. Therefore, in this study, North American regional reanalysis (NARR data set from 1992 to 2002 were employed to investigate the energy budget on various land uses (lake, wetland, agriculture, forest, and urban at a regional scale in Florida. The results showed that the lake and urban areas had high values of energy budget, evaporation, and low Bowen ratio, while the wetland areas have the opposite treads because of the lowest evaporation rate. During drought periods, Bowen ratio, surface temperature, and sensible heat were becoming higher than those of normal years conditions. Finally, by comparing with the observed data, we found NARR had better assimilation of precipitation observations and demonstrated the land use effects from the different coefficient of correlation relationships.

  16. Public budgets for energy RD&D and the effects on energy intensity and pollution levels.

    Science.gov (United States)

    Balsalobre, Daniel; Álvarez, Agustín; Cantos, José María

    2015-04-01

    This study, based on the N-shaped cubic model of the environmental Kuznets curve, analyzes the evolution of per capita greenhouse gas emissions (GHGpc) using not just economic growth but also public budgets dedicated to energy-oriented research development and demonstration (RD&D) and energy intensity. The empirical evidence, obtained from an econometric model of fixed effects for 28 OECD countries during 1994-2010, suggests that energy innovations help reduce GHGpc levels and mitigate the negative impact of energy intensity on environmental quality. When countries develop active energy RD&D policies, they can reduce both the rates of energy intensity and the level of GHGpc emissions. This paper incorporates a moderating variable to the econometric model that emphasizes the effect that GDP has on energy intensity. It also adds a variable that reflects the difference between countries that have made a greater economic effort in energy RD&D, which in turn corrects the GHG emissions resulting from the energy intensity of each country.

  17. Dynamical Mutation of Dark Energy

    CERN Document Server

    Abramo, L R; Liberato, L; Rosenfeld, R

    2007-01-01

    We discuss the intriguing possibility that dark energy may change its equation of state in situations where large dark energy fluctuations are present. We show indications of this dynamical mutation in some generic models of dark energy.

  18. Energy exchange and water budget partitioning in a boreal minerogenic mire

    Science.gov (United States)

    Peichl, Matthias; Sagerfors, JöRgen; Lindroth, Anders; Buffam, Ishi; Grelle, Achim; Klemedtsson, Leif; Laudon, Hjalmar; Nilsson, Mats B.

    2013-03-01

    This study investigated patterns and controls of the seasonal and inter-annual variations in energy fluxes (i.e., sensible heat, H, and latent heat, λE) and partitioning of the water budget (i.e., precipitation, P; evapotranspiration, ET; discharge, Q; and soil water storage, ∆S) over five years (2001-2005) in a boreal oligotrophic fen in northern Sweden based on continuous eddy covariance, water table level (WTL), and weir measurements. For the growing season (May 1 to September 31), the 5 year averages (± standard deviation) of the midday (10:00 to 14:00 h) Bowen ratio (β, i.e., H/λE) was 0.86 ± 0.08. Seasonal and inter-annual variability of β was mainly driven by λE which itself was strongly controlled by both weather (i.e., vapor pressure deficit, D, and net radiation, Rn) and physiological parameters (i.e., surface resistance). During the growing season, surface resistance largely exceeded aerodynamic resistance, which together with low mean values of the actual ET to potential ET ratio (0.55 ± 0.05) and Priestley-Taylor α (0.89) suggests significant physiological constrains on ET in this well-watered fen. Among the water budget components, the inter-annual variability of ET was lower (199 to 298 mm) compared to Q (225 to 752 mm), with each accounting on average for 34 and 65% of the ecosystem water loss, respectively. The fraction of P expended into ET was negatively correlated to P and positively to Rn. Although a decrease in WTL caused a reduction of the surface conductance, the overall effect of WTL on ET was limited. Non-growing season (October 1 to April 30) fluxes of H, λE, and Q were significant representing on average -67%, 13%, and 61%, respectively, of their growing season sums (negative sign indicates opposite flux direction between the two seasons). Overall, our findings suggest that plant functional type composition, P and Rn dynamics (i.e., amount and timing) were the major controls on the partitioning of the mire energy and water

  19. Estimation of IT energy budget during the St. Patrick's Day storm 2015: observations, modeling and challenges.

    Science.gov (United States)

    Verkhoglyadova, O. P.; Meng, X.; Mannucci, A. J.; Mlynczak, M. G.; Hunt, L. A.; Tsurutani, B.

    2015-12-01

    We present estimates for the energy budget of the 2015 St. Patrick's Day storm. Empirical models and coupling functions are used as proxies for energy input due to solar wind-magnetosphere coupling. Fluxes of thermospheric nitric oxide and carbon dioxide cooling emissions are estimated in several latitude ranges. Solar wind data and the Weimer 2005 model for high-latitude electrodynamics are used to drive GITM modeling for the storm. Model estimations for energy partitioning, Joule heating, NO cooling are compared with observations and empirical proxies. We outline challenges in the estimation of the IT energy budget (Joule heating, Poynting flux, particle precipitation) during geomagnetic storms.

  20. Energy methods in dynamics

    CERN Document Server

    Le, Khanh Chau

    2012-01-01

    The above examples should make clear the necessity of understanding the mechanism of vibrations and waves in order to control them in an optimal way. However vibrations and waves are governed by differential equations which require, as a rule, rather complicated mathematical methods for their analysis. The aim of this textbook is to help students acquire both a good grasp of the first principles from which the governing equations can be derived, and the adequate mathematical methods for their solving. Its distinctive features, as seen from the title, lie in the systematic and intensive use of Hamilton's variational principle and its generalizations for deriving the governing equations of conservative and dissipative mechanical systems, and also in providing the direct variational-asymptotic analysis, whenever available, of the energy and dissipation for the solution of these equations. It will be demonstrated that many well-known methods in dynamics like those of Lindstedt-Poincare, Bogoliubov-Mitropolsky, Ko...

  1. Fiscal 1988 draft budget for nuclear energy up 1. 9% to yen 369 billion

    Energy Technology Data Exchange (ETDEWEB)

    1988-01-01

    AT the cabinet meeting held on December 28, the government approved the fiscal 1988 draft budget, with a general account of yen 56.6 trillion. The nuclear energy related budget is yen 181.124 billion from the general account and yen 186.098 billion from the special account for power sources development, totalling yen 367.222 billion, up 1.9% on the previous year. The largest appropriation goes to the Science and Technology Agency (STA) totaling yen 271 billion. The STA is promoting safety studies and R and D for extensive nuclear energy utilization but the budget shows a 0.7% decrease from the previous year, reflecting completion of the construction of JT-60, which is one of the Agency's major projects. MITI, with its budget of yen 91 billion will carry on policies related to the promotion of commercial nuclear power program as well as support for the industrialization program of the nuclear fuel cycle. Nuclear related budget of Ministry of Foreign Affairs is yen 2.8 billion, consisting mainly of IAEA subscriptions and contributions and OECD/NEA subscriptions. Besides these three government agencies, a large sum of yen 1.2 billion is allocated to the Okinawa Development Agency for the prevention and elimination of melon-flies in Kume Island and islands around Okinawa main island. The draft government budget will be submitted to the ordinary session of the Diet when it resumes towards the end of January. After deliberation in the Budget Committees of the House of Representatives and the House of Councilors, the draft budget will be put to the vote in the plenary session. Assuming that all proceeds smoothly, the budget is expected to be approved by the end of March without any major revision.

  2. New estimates of the large-scale Arctic atmospheric energy budget

    Science.gov (United States)

    Porter, David F.; Cassano, John J.; Serreze, Mark C.; Kindig, David N.

    2010-04-01

    New estimates of the current energy budget of the north polar cap (the region north of 70°N) are synthesized by combining data from new atmospheric reanalyses and satellite retrievals. For the period 2000-2005, monthly means from the Clouds and the Earth's Radiant Energy System (CERES) satellite data set are considered to provide the most reliable top-of-atmosphere (TOA) radiation budget. The remaining components of the energy budget, comprising of the energy storage, horizontal convergence of energy, and the net surface flux between the atmospheric and subsurface columns, are compiled using data from the Japanese 25 Year Reanalysis Project (JRA) and the National Centers for Environmental Prediction (NCEP) /National Center for Atmospheric Research (NCAR) Reanalysis (NRA). The annual cycles of energy budget components for the polar cap are fairly consistent between the JRA and NRA, but with some systematic differences. JRA depicts an annual mean surface flux of 14 W m-2 (upward), compared to only 5 W m-2 in NRA. Most of this disparity appears to be due to differences in sea ice and albedo. Horizontal atmospheric energy flux divergence calculated using mass-corrected flux values contains artifacts leading to unphysical results. We argue that backing out the energy flux convergence as a residual from the net surface heat flux and time change in energy storage from each reanalysis, and the TOA radiation budget from CERES, provides for more physically realistic results in the Arctic. Monthly mean anomalies of budget terms, used to examine conditions leading to the extreme seasonal sea ice extent minimum of September 2005, point to the importance of albedo feedback.

  3. Conservation Laws and Energy Budget in a Static Universe

    Science.gov (United States)

    Heymann, Yuri

    2016-10-01

    The universe is characterized by large concentrations of energy contained in small, dense areas such as galaxies, which radiate energy towards the surrounding space. However, no current theory balances the loss of energy of galaxies, a requirement for a conservative universe. This study is an investigation of the physics nature might use to maintain the energy differential between its dense parts and the vacuum. We propose time contraction as a principle to maintain this energy differential. Time contraction has the following effects: photons lose energy, while masses gain potential energy and lose kinetic energy. From the virial theorem, which applies to a system of bodies, we find that the net energy resulting from the gain in potential energy and the loss in kinetic energy remains unchanged, meaning that the orbitals of stars in galaxies remain unaffected by time contraction. However, each object in a galaxy has an internal potential energy leading to a surplus of energy within the object. This internal energy surplus should balance with the energy radiated at the level of a galaxy. We illustrate this principle with a calculation of the energy balance of the Milky Way.

  4. The Energy Budget of a Southwest Vortex With Heavy Rainfall over South China

    Institute of Scientific and Technical Information of China (English)

    FU Shenming; SUN Jianhua; ZHAO Sixiong; LI Wanli

    2011-01-01

    Energy budgets were analyzed to study the development of an eastward propagating southwest vortex (SWV) associated with heavy rainfall over southern China (11-13 June 2008). The results show that kinetic energy (KE) generation and a dvection were the most important KE sources, while friction and sub-grid processes were the main KE sinks. There was downward conversion from divergent to rotational wind KE consistent with the downward stretching of SWVs. The Coriolis force was important for the formation and maintenance of the SWV. Convergence was also an important factor for maintenance, as was vertical motion during the mature stage of the SWV and the formation stage of a newly formed vortex (vortex B). The conversion from available potential energy (APE) to KE of divergent wind can lead to strong convection. Vertical motion influenced APE by dynamical and thermal processes which had opposite effects.The variation of APE was related to the heavy rainfall and convection; in this case, vertical motion with direct thermal circulation was the most important way in which APE was released, while latent heat release and vertical temperature advection were important for APE generation.

  5. Effects of activity and energy budget balancing algorithm on laboratory performance of a fish bioenergetics model

    Science.gov (United States)

    Madenjian, Charles P.; David, Solomon R.; Pothoven, Steven A.

    2012-01-01

    We evaluated the performance of the Wisconsin bioenergetics model for lake trout Salvelinus namaycush that were fed ad libitum in laboratory tanks under regimes of low activity and high activity. In addition, we compared model performance under two different model algorithms: (1) balancing the lake trout energy budget on day t based on lake trout energy density on day t and (2) balancing the lake trout energy budget on day t based on lake trout energy density on day t + 1. Results indicated that the model significantly underestimated consumption for both inactive and active lake trout when algorithm 1 was used and that the degree of underestimation was similar for the two activity levels. In contrast, model performance substantially improved when using algorithm 2, as no detectable bias was found in model predictions of consumption for inactive fish and only a slight degree of overestimation was detected for active fish. The energy budget was accurately balanced by using algorithm 2 but not by using algorithm 1. Based on the results of this study, we recommend the use of algorithm 2 to estimate food consumption by fish in the field. Our study results highlight the importance of accurately accounting for changes in fish energy density when balancing the energy budget; furthermore, these results have implications for the science of evaluating fish bioenergetics model performance and for more accurate estimation of food consumption by fish in the field when fish energy density undergoes relatively rapid changes.

  6. Estimation of energy budget of ionosphere-thermosphere system during two CIR-HSS events: observations and modeling

    Science.gov (United States)

    Verkhoglyadova, Olga; Meng, Xing; Mannucci, Anthony J.; Tsurutani, Bruce T.; Hunt, Linda A.; Mlynczak, Martin G.; Hajra, Rajkumar; Emery, Barbara A.

    2016-04-01

    We analyze the energy budget of the ionosphere-thermosphere (IT) system during two High-Speed Streams (HSSs) on 22-31 January, 2007 (in the descending phase of solar cycle 23) and 25 April-2 May, 2011 (in the ascending phase of solar cycle 24) to understand typical features, similarities, and differences in magnetosphere-ionosphere-thermosphere (IT) coupling during HSS geomagnetic activity. We focus on the solar wind energy input into the magnetosphere (by using coupling functions) and energy partitioning within the IT system during these intervals. The Joule heating is estimated empirically. Hemispheric power is estimated based on satellite measurements. We utilize observations from TIMED/SABER (Thermosphere-Ionosphere-Mesosphere Energetics and Dynamics/Sounding of the Atmosphere using Broadband Emission Radiometry) to estimate nitric oxide (NO) and carbon dioxide (CO2) cooling emission fluxes. We perform a detailed modeling study of these two similar HSS events with the Global Ionosphere-Thermosphere Model (GITM) and different external driving inputs to understand the IT response and to address how well the model reproduces the energy transport. GITM is run in a mode with forecastable inputs. It is shown that the model captures the main features of the energy coupling, but underestimates NO cooling and auroral heating in high latitudes. Lower thermospheric forcing at 100 km altitude is important for correct energy balance of the IT system. We discuss challenges for a physics-based general forecasting approach in modeling the energy budget of moderate IT storms caused by HSSs.

  7. United States Department of Energy Budget Highlights FY 1995

    Energy Technology Data Exchange (ETDEWEB)

    O`Leary, H.R.

    1994-02-01

    The Department of Energy is entrusted to contribute to the welfare of the Nation by providing the scientific and educational foundation or the technology, policy, and institutional leadership necessary to achieve efficiency in energy use, diversity in energy sources, and access to technical information required for a more productive and competitive economy, improved environmental quality, and a secure national defense.

  8. First-Principles Definition and Measurement of Planetary Electromagnetic-Energy Budget

    Science.gov (United States)

    Mishchenko, Michael I.; Lock, James A.; Lacis, Andrew A.; Travis, Larry D.; Cairns, Brian

    2016-01-01

    The imperative to quantify the Earths electromagnetic-energy budget with an extremely high accuracy has been widely recognized but has never been formulated in the framework of fundamental physics. In this paper we give a first-principles definition of the planetary electromagnetic-energy budget using the Poynting- vector formalism and discuss how it can, in principle, be measured. Our derivation is based on an absolute minimum of theoretical assumptions, is free of outdated notions of phenomenological radiometry, and naturally leads to the conceptual formulation of an instrument called the double hemispherical cavity radiometer (DHCR). The practical measurement of the planetary energy budget would require flying a constellation of several dozen planet-orbiting satellites hosting identical well-calibrated DHCRs.

  9. A perspective on the states` role in the Department of Energy`s Office of Environmental Management budget process

    Energy Technology Data Exchange (ETDEWEB)

    Carter, J.P.; Hinman, P. [Carter, Brock & Hinman, Boise, ID (United States)

    1995-12-31

    Responding in 1994 to proposed budget reductions and predicted funding shortfalls, the Office of Environmental Management at the Department of Energy began working closely with its regulators and stakeholders to prioritize activities. In a series of national and site specific meetings held with representatives of states, the Environmental Protection Agency, Indian tribes and the public, the Department of Energy brought regulators and other stakeholders into its budget development process in a {open_quotes}bottoms up{close_quotes} approach to the prioritization of activities at each of its sites. This paper presents an overview of this process which began last year and will highlight its unique cooperative nature. This paper will assess ways of institutionalizing this process. It also identifies issues to be addressed in resolving matters related to future budgets. Areas of concern to the Department of Energy`s host states and their regulators will be identified as they relate to waste management, cleanup and facility transition activities.

  10. Using energy budgets to combine ecology and toxicology in a mammalian sentinel species

    Science.gov (United States)

    Desforges, Jean-Pierre W.; Sonne, Christian; Dietz, Rune

    2017-04-01

    Process-driven modelling approaches can resolve many of the shortcomings of traditional descriptive and non-mechanistic toxicology. We developed a simple dynamic energy budget (DEB) model for the mink (Mustela vison), a sentinel species in mammalian toxicology, which coupled animal physiology, ecology and toxicology, in order to mechanistically investigate the accumulation and adverse effects of lifelong dietary exposure to persistent environmental toxicants, most notably polychlorinated biphenyls (PCBs). Our novel mammalian DEB model accurately predicted, based on energy allocations to the interconnected metabolic processes of growth, development, maintenance and reproduction, lifelong patterns in mink growth, reproductive performance and dietary accumulation of PCBs as reported in the literature. Our model results were consistent with empirical data from captive and free-ranging studies in mink and other wildlife and suggest that PCB exposure can have significant population-level impacts resulting from targeted effects on fetal toxicity, kit mortality and growth and development. Our approach provides a simple and cross-species framework to explore the mechanistic interactions of physiological processes and ecotoxicology, thus allowing for a deeper understanding and interpretation of stressor-induced adverse effects at all levels of biological organization.

  11. Using energy budgets to combine ecology and toxicology in a mammalian sentinel species

    Science.gov (United States)

    Desforges, Jean-Pierre W.; Sonne, Christian; Dietz, Rune

    2017-01-01

    Process-driven modelling approaches can resolve many of the shortcomings of traditional descriptive and non-mechanistic toxicology. We developed a simple dynamic energy budget (DEB) model for the mink (Mustela vison), a sentinel species in mammalian toxicology, which coupled animal physiology, ecology and toxicology, in order to mechanistically investigate the accumulation and adverse effects of lifelong dietary exposure to persistent environmental toxicants, most notably polychlorinated biphenyls (PCBs). Our novel mammalian DEB model accurately predicted, based on energy allocations to the interconnected metabolic processes of growth, development, maintenance and reproduction, lifelong patterns in mink growth, reproductive performance and dietary accumulation of PCBs as reported in the literature. Our model results were consistent with empirical data from captive and free-ranging studies in mink and other wildlife and suggest that PCB exposure can have significant population-level impacts resulting from targeted effects on fetal toxicity, kit mortality and growth and development. Our approach provides a simple and cross-species framework to explore the mechanistic interactions of physiological processes and ecotoxicology, thus allowing for a deeper understanding and interpretation of stressor-induced adverse effects at all levels of biological organization. PMID:28387336

  12. Energy budget of surface waves in the global ocean

    Institute of Scientific and Technical Information of China (English)

    TENG Yong; YANG Yongzeng; QIAO Fangli; LU Jing; YIN Xunqiang

    2009-01-01

    Mechanical energy input from atmosphere and losses from wave-breaking dissipation of sea surface waves are estimated by a direct scheme. This scheme is based on the integration in the wavenumber space of the wind input and breaking dissipation source functions of the MASNUM wave model.The global amount of wind energy input, averaged in 2005, is about 57 TW, and the wave-breaking dissipation summed in deep-water is about 33 TW, over a half of the wind energy input. The residual may be dissipated by beach processes. Global distributions of the energy input and breaking dissipation concentrate in the westerlies of the Southern Hemisphere.

  13. Conservation and solar energy program: congressional budget request, FY 1982

    Energy Technology Data Exchange (ETDEWEB)

    None

    1981-01-01

    Funding summaries are presented for the Conservation and Solar Energy Program funding information and program overview on energy conservation (Volume 7 of 7, DOE/CR-0011/2) are included for the Buildings and Community Systems, Industrial, Transportation; State and Local, Multi-Sector, Energy Impact Assistance, and Residential/Commercial retrofit programs. Funding information and program overviews on solar technology (Volume 2 of 7, DOE/CR-011/2) are included for Active and Passive Solar Heating and Cooling, Photovoltaics Energy Systems, Solar Thermal Power Systems, Biomass Energy Systems, Wind Energy Conversion Systems, Ocean Systems, Solar International Activities, Solar Information Systems, SERI Facility, MX-RES, Program Direction, and Alcohol Fuels programs. Information and overviews on energy production, demonstration, and distribution (Volume 6 of 7, DOE/CR-0011/2) are given for the solar program. A funding summary and a program overview are included for electrochemical and physical and chemical storage systems as appearing in DOE/CR-0011/2, Volume 3 of 7. Relevant tabulated data from the FY 1981. Request to the Congress are presented for Supplementals, Rescissions, and Deferrals. (MCW)

  14. Energy budget and propagation of faults via shearing and opening using work optimization

    Science.gov (United States)

    Madden, Elizabeth H.; Cooke, Michele L.; McBeck, Jessica

    2017-08-01

    We present numerical models of faults propagating by work optimization in a homogeneous medium. These simulations allow quantification and comparison of the energy budgets of fault growth by shear versus tensile failure. The energy consumed by growth of a fault, Wgrow, propagating by in-line shearing is 76% of the total energy associated with that growth, while 24% is spent on frictional work during propagation. Wgrow for a fault propagating into intact rock by tensile failure, at an angle to the parent fault, consumes 60% of the work budget, while only 6% is consumed by frictional work associated with propagation. Following the conservation of energy, this leaves 34% of the energy budget available for other activities and suggests that out-of-plane propagation of faults in Earth's crust may release energy for other processes, such as permanent damage zone formation or rupture acceleration. Comparison of these estimates of Wgrow with estimates of the critical energy release rate and earthquake fracture energy at several scales underscores their theoretical similarities and their dependence on stress drop.

  15. Towards closing the surface energy budget of a mid-latitude grassland

    NARCIS (Netherlands)

    Jacobs, A.F.G.; Heusinkveld, B.G.; Holtslag, A.A.M.

    2008-01-01

    Observations for May and August, 2005, from a long-term grassland meteorological station situated in central Netherlands were used to evaluate the closure of the surface energy budget. We compute all possible enthalpy changes, such as the grass cover heat storage, dew water heat storage, air mass he

  16. Selected translated abstracts of Russian-language climate-change publications: I, Surface energy budget

    Energy Technology Data Exchange (ETDEWEB)

    Burtis, M.D. [comp.

    1992-09-01

    This report presents abstracts (translated into English) of important Russian-language literature concerning the surface energy budget as it relates to climate change. In addition to the bibliographic citations and abstracts translated into English, this report presents the original citations and abstracts in Russian. Author and title indexes are included, to assist the reader in locating abstracts of particular interest.

  17. Energy budget of the magnetosphere-ionosphere system in solar Cycle 23

    Institute of Scientific and Technical Information of China (English)

    XU WenYao; DU AiMin

    2012-01-01

    The energy budget of the magnetosphere-ionosphere (MI) system during 1998-2008 was examined by using Akasofu's epsilon function.The results showed that 1) the yearly average rate of solar wind energy input into the MI system was 4.51 GGJ (GGJ=1018 J),while the yearly average total dissipation was 4.30 GGJ; 2) the energy partitioning in the ring current and polar region was 56%:44%; 3) the energy input and dissipation processes continuously proceeded both in storm-substorm events and less disturbed intervals,suggesting the significant contribution of slow but long-lasting energy process during the less disturbance periods to the total energy budget.In addition,we found in this study an interesting phenomenon “self-adjustment ability” of the MI system which behaves just like a water reservoir.During solar active years,the input energy is more than the dissipated energy,implying that a portion of the input energy is not immediately released,but is stored in the magnetosphere.On the other hand,during less active years,the dissipated energy is more than the input energy,implying that the previously stored energy makes up for the energy input shortage in this period.

  18. Alterations in the energy budget of Arctic benthic species exposed to oil-related compounds

    Energy Technology Data Exchange (ETDEWEB)

    Olsen, Gro Harlaug [Akvaplan-niva, Polar Environmental Center, N-9296 Tromso (Norway) and Norwegian College of Fishery Science, University of Tromso, N-9037 Tromso (Norway)]. E-mail: gho@akvaplan.niva.noph; Sva, Eirin [Akvaplan-niva, Polar Environmental Center, N-9296 Tromso (Norway); Carroll, JoLynn [Akvaplan-niva, Polar Environmental Center, N-9296 Tromso (Norway); Camus, Lionel [Akvaplan-niva, Polar Environmental Center, N-9296 Tromso (Norway); De Coen, Wim [Laboratory for Ecophysiology, Biochemistry and Toxicology, University of Antwerp (UA), Groenenborgerlaan 171, B-2020 Antwerp (Belgium); Smolders, Roel [Laboratory for Ecophysiology, Biochemistry and Toxicology, University of Antwerp (UA), Groenenborgerlaan 171, B-2020 Antwerp (Belgium); Environmental Toxicology, VITO, Boeretang 200, B-2400 Mol (Belgium); Overaas, Helene [Norwegian Institute for Water Research (NIVA), CIENS, Gaustadalleen, N-0316 Oslo (Norway); Multiconsult AS, Hoffsveien 1, N-0275 Oslo (Norway); Hylland, Ketil [Norwegian Institute for Water Research (NIVA), CIENS, Gaustadalleen, N-0316 Oslo (Norway); Department of Biology, University of Oslo, P.O. Box 1066, Blindern, N-0316 Oslo (Norway)

    2007-06-15

    We studied cellular energy allocation (CEA) in three Arctic benthic species (Gammarus setosus (Amphipoda), Onisimus litoralis (Amphipoda), and Liocyma fluctuosa (Bivalvia)) exposed to oil-related compounds. The CEA biomarker measures the energy budget of organisms by biochemically assessing changes in energy available (carbohydrates, protein and lipid content) and the integrated energy consumption (electron transport system activity (ETS) as the cellular aspect of respiration). Energy budget was measured in organisms subjected to water-accommodated fraction (WAF) of crude oil and drill cuttings (DC) to evaluate whether these compounds affect the energy metabolism of the test species. We observed significantly lower CEA values and higher ETS activity in G. setosus subjected to WAF treatment compared to controls (p {<=} 0.03). Higher CEA value and lower cellular respiration were observed in O. litoralis exposed to DC compared to controls (p = 0.02). No difference in the energy budget of L. fluctuosa was observed between the treatments (p {>=} 0.19). Different responses to oil-related compounds between the three test species are likely the result of differences in feeding and burrowing behavior and species-specific sensitivity to petroleum-related compounds.

  19. The Energy Budget of a Southwest Vortex With Heavy Rainfall over South China

    Institute of Scientific and Technical Information of China (English)

    2011-01-01

    Energy budgets were analyzed to study the development of an eastward propagating southwest vortex (SWV) associated with heavy rainfall over southern China(11-13 June 2008).The results show that kinetic energy(KE) generation and advection were the most important KE sources,while friction and sub-grid processes were the main KE sinks.There was downward conversion from divergent to rotational wind KE consistent with the downward stretching of SWVs.The Coriolis force was important for the formation and maintenance of the SWV.Convergence was also an important factor for maintenance,as was vertical motion during the mature stage of the SWV and the formation stage of a newly formed vortex(vortex B).The conversion from available potential energy(APE) to KE of divergent wind can lead to strong convection.Vertical motion influenced APE by dynamical and thermal processes which had opposite effects. The variation of APE was related to the heavy rainfall and convection;in this case,vertical motion with direct thermal circulation was the most important way in which APE was released,while latent heat release and vertical temperature advection were important for APE generation.

  20. Impact of engineered zinc oxide nanoparticles on the energy budgets of Mytilus galloprovincialis

    Science.gov (United States)

    Muller, Erik B.; Hanna, Shannon K.; Lenihan, Hunter S.; Miller, Robert J.; Nisbet, Roger M.

    2014-11-01

    This paper characterizes the sublethal impact of engineered ZnO nanoparticles on the individual performance of the marine mussel Mytilus galloprovincialis within the context of Dynamic Energy Budget theory, thereby allowing an integrated evaluation of the impact of multiple stressors on various endpoints. Data include measurements of the impact of ZnO nanoparticles on body burden, feeding, respiration, shell length, biomass, and mortality of mussels kept in laboratory tanks for over 100 days. ZnO nanoparticles in the environment impair the mussels' feeding rate (EC50 for the maximum feeding rate is 1.5 mg ZnO nanoparticles L- 1). Zn accumulated in tissue increases respiration (EC50 for the respiration rate is 0.9 mg environmental ZnO nanoparticles L- 1 with the body burden having reached its ultimate level), indicating that maintenance processes are more affected by ZnO nanoparticles than feeding. The feeding regime constrained growth and biomass production to the extent that the impact of ZnO nanoparticles on these processes was undetectable, yet the remaining measurements allowed the estimation of the toxicity parameters. The toxicity representation, combined with the DEB model, allowed the calculation of the effect of the nanoparticles on the expected lifetime production of reproductive matter. EC50 for the expected lifetime production of reproductive matter is less than 0.25 mg ZnO nanoparticles L- 1, indicating that that the ecological impact of ZnO nanoparticle exposure is stronger than its impact on individual physiological rates.

  1. Mass and energy budgets of animals: Behavioral and ecological implications

    Energy Technology Data Exchange (ETDEWEB)

    Porter, W.P.

    1989-08-01

    We are now beginning a long term exploration of environmental constraints on continent-wide growth and reproduction in ectotherms and endotherms. We have begun to study a new lizard species, Cnemidophorus sexlineatus, an active forager with a wide geographic distribution. Our state-of-the-art vacuum gas analysis system continues to function well, and we are using doubly labeled wear routinely in our research to test our first principle calculations of field metabolism and water loss. The computer controlled respirometer system routinely measures respiratory gases and body temperatures in small living mammals. We have just added two more species of mammals, Gerbillus allenbyi and Gerbillus pyramidum from Israel, to the list of 9 species of mammals and two species of birds for which we have successfully tested the dry fur model. We use gas respirometry in the laboratory and doubly labeled water in the field to verify the calculations of our models. We continue to focus on the dynamics of interactions between environmental and animal variance and their implications for growth and reproduction and the links between environmental effects on organisms and population dynamics. 9 refs., 14 figs.

  2. Carbon Budget and its Dynamics over Northern Eurasia Forest Ecosystems

    Science.gov (United States)

    Shvidenko, Anatoly; Schepaschenko, Dmitry; Kraxner, Florian; Maksyutov, Shamil

    2016-04-01

    -2012. It has been shown that the Net Ecosystem Carbon Budget (NECB) of Russian forests for this period was in range of 0.5-0.7 Pg C yr-1 with a slight negative trend during the period due to acceleration of disturbance regimes and negative impacts of weather extremes (heat waves etc.). Uncertainties of the FCA for individual years were estimated at about 25% (CI 0.9). It has been shown that some models (e.g. majority of DGVMs) do not describe some processes on permafrost satisfactory while results of applications of ensembles of inverse models on average are closed to empirical assessments. A most important conclusion from this experience is that future improvements of knowledge of carbon cycling of Northern Eurasia forests requires development of an integrated observing system as a unified information background, as well as systems methodological improvements of all methods of cognition of carbon cycling.

  3. Satellite Monitoring of the Surface Water and Energy Budget in the Central Tibetan Plateau

    Institute of Scientific and Technical Information of China (English)

    YANG Kun; Toshio KOIKE

    2008-01-01

    The water and energy cycle in the Tibetan Plateau is an important component of Monsoon Asia and the global energy and water cycle. Using data at a CEOP (Coordinated Enhanced Observing Period)-Tibet site, this study presents a first-order evaluation on the skill of weather forecasting from GCMs and satellites in producing precipitation and radiation estimates. The satellite data, together with the satellite leaf area index, are then integrated into a land data assimilation system (LDAS-UT) to estimate the soil moisture and surface energy budget on the Plateau. The system directly assimilates the satellite microwave brightness temperature, which is strongly affected by soil moisture but not by cloud layers, into a simple biosphere model. A major feature of this system is a dual-pass assimilation technique, which can auto-calibrate model parameters in one pass and estimate the soil moisture and energy budget in the other pass. The system outputs, including soil moisture, surface temperature, surface energy partition, and the Bowen ratio, are compared with observations, land surface models, the Global Land Data Assimilation System, and four general circulation models. The results show that this satellite data-based system has a high potential for a reliable estimation of the regional surface energy budget on the Plateau.

  4. Projected Benefits of Federal Energy Efficiency and Renewable Energy Programs - FY 2008 Budget Request

    Energy Technology Data Exchange (ETDEWEB)

    2007-03-01

    This document summarizes the results of the benefits analysis of EERE's programs, as described in the FY 2008 Budget Request. EERE estimates benefits for its overall portfolio and for each of its nine Research, Development, Demonstration, and Deployment (RD3) programs. Benefits for the FY 2008 budget request are estimated for the midterm (2008-2030) and long term (2030-2050).

  5. Dynamics of Teleparallel Dark Energy

    CERN Document Server

    Wei, Hao

    2011-01-01

    Recently, motivated by the similar one in the framework of General Relativity (GR), Geng et al.} proposed to allow a non-minimal coupling between quintessence and gravity in the framework of teleparallel gravity. They found that this non-minimally coupled quintessence in the framework of teleparallel gravity has a richer structure, and named it "teleparallel dark energy". In the present work, we note that there might be a deep and unknown connection between teleparallel dark energy and Elko spinor dark energy. Motivated by this observation and the previous results of Elko spinor dark energy, we try to study the dynamics of teleparallel dark energy. We find that there exist only some dark-energy-dominated de Sitter attractors. No scaling attractor has been found unfortunately. So, similar to Elko spinor dark energy, teleparallel dark energy is also plagued with the cosmological coincidence problem, although it has an extra free model parameter $\\xi$.

  6. Modern Era Retrospective-analysis for Research and Applications (MERRA) Global Water and Energy Budgets

    Science.gov (United States)

    Bosilovich, Michael G.; Chen, Junye

    2009-01-01

    In the Summer of 2009, NASA's Modern Era Retrospective-analysis for Research and Applications (MERRA) will have completed 28 years of global satellite data analyses. Here, we characterize the global water and energy budgets of MERRA, compared with available observations and the latest reanalyses. In this analysis, the climatology of the global average components are studied as well as the separate land and ocean averages. In addition, the time series of the global averages are evaluated. For example, the global difference of precipitation and evaporation generally shows the influence of water vapor observations on the system. Since the observing systems change in time, especially remotely sensed observations of water, significant temporal variations can occur across the 28 year record. These then are also closely connected to changes in the atmospheric energy and water budgets. The net imbalance of the energy budget at the surface can be large and different signs for different reanalyses. In MERRA, the imbalance of energy at the surface tends to improve with time being the smallest during the most recent and abundant satellite observations.

  7. Measurement of the Turbulence Kinetic Energy Budget of a Turbulent Planar Wake Flow in Pressure Gradients

    Science.gov (United States)

    Liu, Xiao-Feng; Thomas, Flint O.; Nelson, Robert C.

    2001-01-01

    Turbulence kinetic energy (TKE) is a very important quantity for turbulence modeling and the budget of this quantity in its transport equation can provide insight into the flow physics. Turbulence kinetic energy budget measurements were conducted for a symmetric turbulent wake flow subjected to constant zero, favorable and adverse pressure gradients in year-three of research effort. The purpose of this study is to clarify the flow physics issues underlying the demonstrated influence of pressure gradient on wake development and provide experimental support for turbulence modeling. To ensure the reliability of these notoriously difficult measurements, the experimental procedure was carefully designed on the basis of an uncertainty analysis. Four different approaches, based on an isotropic turbulence assumption, a locally axisymmetric homogeneous turbulence assumption, a semi-isotropy assumption and a forced balance of the TKE equation, were applied for the estimate of the dissipation term. The pressure transport term is obtained from a forced balance of the turbulence kinetic energy equation. This report will present the results of the turbulence kinetic energy budget measurement and discuss their implication on the development of strained turbulent wakes.

  8. Modern Era Retrospective-analysis for Research and Applications (MERRA) Global Water and Energy Budgets

    Science.gov (United States)

    Bosilovich, Michael G.; Chen, Junye

    2009-01-01

    In the Summer of 2009, NASA's Modern Era Retrospective-analysis for Research and Applications (MERRA) will have completed 28 years of global satellite data analyses. Here, we characterize the global water and energy budgets of MERRA, compared with available observations and the latest reanalyses. In this analysis, the climatology of the global average components are studied as well as the separate land and ocean averages. In addition, the time series of the global averages are evaluated. For example, the global difference of precipitation and evaporation generally shows the influence of water vapor observations on the system. Since the observing systems change in time, especially remotely sensed observations of water, significant temporal variations can occur across the 28 year record. These then are also closely connected to changes in the atmospheric energy and water budgets. The net imbalance of the energy budget at the surface can be large and different signs for different reanalyses. In MERRA, the imbalance of energy at the surface tends to improve with time being the smallest during the most recent and abundant satellite observations.

  9. Estimating Heat Fluxes by Merging Profile Formulae and the Energy Budget with a Variational Technique

    Institute of Scientific and Technical Information of China (English)

    张述文; 邱崇践; 张卫东

    2004-01-01

    A variational technique (VT) is applied to estimate surface sensible and latent heat fluxes based on observations of air temperature, wind speed, and humidity, respectively, at three heights (1 m, 4 m, and 10m), and the surface energy and radiation budgets by the surface energy and radiation system (SERBS). The method fully uses all information provided by the measurements of air temperature, wind, and humidity profiles, the surface energy budget, and the similarity profile formulae as well. Data collected at Feixi experiment station installed by the China Heavy Rain Experiment and Study (HeRES) Program are used to test the method. Results show that the proposed technique can overcome the well-known unstablility problem that occurs when the Bowen method becomes singular; in comparison with the profile method, it reduces both the sensitivities of latent heat fluxes to observational errors in humidity and those of sensible heat fluxes to observational errors in temperature, while the estimated heat fluxes approximately satisfy the surface energy budget. Therefore, the variational technique is more reliable and stable than the two conventional methods in estimating surface sensible and latent heat fluxes.

  10. Estimation of energy budget of ionosphere-thermosphere system during two CIR-HSS events: observations and modeling

    Directory of Open Access Journals (Sweden)

    Verkhoglyadova Olga

    2016-01-01

    Full Text Available We analyze the energy budget of the ionosphere-thermosphere (IT system during two High-Speed Streams (HSSs on 22–31 January, 2007 (in the descending phase of solar cycle 23 and 25 April–2 May, 2011 (in the ascending phase of solar cycle 24 to understand typical features, similarities, and differences in magnetosphere-ionosphere-thermosphere (IT coupling during HSS geomagnetic activity. We focus on the solar wind energy input into the magnetosphere (by using coupling functions and energy partitioning within the IT system during these intervals. The Joule heating is estimated empirically. Hemispheric power is estimated based on satellite measurements. We utilize observations from TIMED/SABER (Thermosphere-Ionosphere-Mesosphere Energetics and Dynamics/Sounding of the Atmosphere using Broadband Emission Radiometry to estimate nitric oxide (NO and carbon dioxide (CO2 cooling emission fluxes. We perform a detailed modeling study of these two similar HSS events with the Global Ionosphere-Thermosphere Model (GITM and different external driving inputs to understand the IT response and to address how well the model reproduces the energy transport. GITM is run in a mode with forecastable inputs. It is shown that the model captures the main features of the energy coupling, but underestimates NO cooling and auroral heating in high latitudes. Lower thermospheric forcing at 100 km altitude is important for correct energy balance of the IT system. We discuss challenges for a physics-based general forecasting approach in modeling the energy budget of moderate IT storms caused by HSSs.

  11. Revisiting the Earth's sea-level and energy budgets from 1961 to 2008

    NARCIS (Netherlands)

    Church, J.E.; White, N.J.; Konikow, L.F.; Domingues, C.M.; Cogley, J.G.; Rignot, Eric; Gregory, J.M.; van den Broeke, M.R.|info:eu-repo/dai/nl/073765643; Monaghan, A.J.; Velicogna, I.

    2011-01-01

    We review the sea-level and energy budgets together from 1961, using recent and updated estimates of all terms. From 1972 to 2008, the observed sea-level rise (1.8 ± 0.2 mm yr−1 from tide gauges alone and 2.1 ± 0.2 mm yr−1 from a combination of tide gauges and altimeter observations) agrees well

  12. Revisiting the Earth's sea-level and energy budgets from 1961 to 2008

    NARCIS (Netherlands)

    Church, J.E.; White, N.J.; Konikow, L.F.; Domingues, C.M.; Cogley, J.G.; Rignot, Eric; Gregory, J.M.; van den Broeke, M.R.; Monaghan, A.J.; Velicogna, I.

    2011-01-01

    We review the sea-level and energy budgets together from 1961, using recent and updated estimates of all terms. From 1972 to 2008, the observed sea-level rise (1.8 ± 0.2 mm yr−1 from tide gauges alone and 2.1 ± 0.2 mm yr−1 from a combination of tide gauges and altimeter observations) agrees well wit

  13. Introduction to Cost Control Strategies for Zero Energy Buildings: High-Performance Design and Construction on a Budget (Fact Sheet)

    Energy Technology Data Exchange (ETDEWEB)

    2014-09-01

    Momentum behind zero energy building design and construction is increasing, presenting a tremendous opportunity for advancing energy performance in the commercial building industry. At the same time, there is a lingering perception that zero energy buildings must be cost prohibitive or limited to showcase projects. Fortunately, an increasing number of projects are demonstrating that high performance can be achieved within typical budgets. This factsheet highlights replicable, recommended strategies for achieving high performance on a budget, based on experiences from past projects.

  14. The photospheric energy and helicity budgets of the flux-injection hypothesis

    CERN Document Server

    Schuck, P W

    2010-01-01

    The flux-injection hypothesis for driving coronal mass ejections (CMEs) requires the transport of substantial magnetic energy and helicity flux through the photosphere concomitant with the eruption. Under the magnetohydrodynamics approximation, these fluxes are produced by twisting magnetic field and/or flux emergence in the photosphere. A CME trajectory, observed 2000 September 12th and fitted with a flux-rope model constrains energy and helicity budgets for testing the flux-injection hypothesis. Optimal velocity profiles for several driving scenarios are estimated by minimizing the photospheric plasma velocities for a cylindrically symmetric flux-rope magnetic field subject to the flux budgets required by the flux-rope model. Ideal flux-injection, involving only flux-emergence, requires hypersonic up-flows in excess of the solar escape velocity 617 km/s over an area of 6\\times10^8 km^2 to satisfy the energy and helicity budgets of the flux-rope model. These estimates are compared with magnetic field and Dop...

  15. A comparison of observed and numerically predicted eddy kinetic energy budgets for a developing extratropical cyclone

    Science.gov (United States)

    Dare, P. M.; Smith, P. J.

    1983-01-01

    The eddy kinetic energy budget is calculated for a 48-hour forecast of an intense occluding winter cyclone associated with a strong well-developed jet stream. The model output consists of the initialized (1200 GMT January 9, 1975) and the 12, 24, 36, and 48 hour forecast fields from the Drexel/NCAR Limited Area Mesoscale Prediction System (LAMPS) model. The LAMPS forecast compares well with observations for the first 24 hours, but then overdevelops the low-level cyclone while inadequately developing the upper-air wave and jet. Eddy kinetic energy was found to be concentrated in the upper-troposphere with maxima flanking the primary trough. The increases in kinetic energy were found to be due to an excess of the primary source term of kinetic energy content, which is the horizontal flux of eddy kinetic energy over the primary sinks, and the generation and dissipation of eddy kinetic energy.

  16. An individual-based model of Zebrafish population dynamics accounting for energy dynamics

    DEFF Research Database (Denmark)

    Beaudouin, Remy; Goussen, Benoit; Piccini, Benjamin

    2015-01-01

    Developing population dynamics models for zebrafish is crucial in order to extrapolate from toxicity data measured at the organism level to biological levels relevant to support and enhance ecological risk assessment. To achieve this, a dynamic energy budget for individual zebrafish (DEB model......, the predictions of the DEB-IBM were compared to existing observations on natural zebrafish populations and the predicted population dynamics are realistic. While our zebrafish DEB-IBM model can still be improved by acquiring new experimental data on the most uncertain processes (e.g. survival or feeding), it can...

  17. Archetypal energy landscapes: dynamical diagnosis.

    Science.gov (United States)

    Despa, Florin; Wales, David J; Berry, R Stephen

    2005-01-08

    Recent studies have identified several motifs for potential energy surfaces corresponding to distinct dynamic and thermodynamic properties. The corresponding disconnectivity graphs were identified as "palm tree," "willow tree," and "banyan tree" patterns. In the present contribution we present a quantitative analysis of the relation between the topography and dynamics for each of these motifs. For the palm tree and willow tree forms we find that the arrangement of the stationary points in the monotonic sequences with respect to the global minimum is the most important factor in establishing the kinetic properties. However, the results are somewhat different for motifs involving a rough surface with several deep basins (banyan tree motif), with large barriers relative to the energy differences between minima. Here it is the size of the barrier for escape from the region relative to the barriers at the bottom that is most important. The present results may be helpful in distinguishing between the dynamics of "structure seeking" and "glass forming" systems.

  18. AGN JET KINETIC POWER AND THE ENERGY BUDGET OF RADIO GALAXY LOBES

    Energy Technology Data Exchange (ETDEWEB)

    Godfrey, L. E. H. [International Centre for Radio Astronomy Research, Curtin University, GPO Box U1987, Perth, WA 6102 (Australia); Shabala, S. S., E-mail: L.Godfrey@curtin.edu.au [School of Mathematics and Physics, Private Bag 37, University of Tasmania, Hobart, TAS 7001 (Australia)

    2013-04-10

    Recent results based on the analysis of radio galaxies and their hot X-ray emitting atmospheres suggest that non-radiating particles dominate the energy budget in the lobes of FR I radio galaxies, in some cases by a factor of more than 1000, while radiating particles dominate the energy budget in FR II radio galaxy lobes. This implies a significant difference in the radiative efficiency of the two morphological classes. To test this hypothesis, we have measured the kinetic energy flux for a sample of 3C FR II radio sources using a new method based on the observed parameters of the jet terminal hotspots, and compared the resulting Q{sub jet}-L{sub radio} relation to that obtained for FR I radio galaxies based on X-ray cavity measurements. Contrary to expectations, we find approximate agreement between the Q{sub jet}-L{sub radio} relations determined separately for FR I and FR II radio galaxies. This result is ostensibly difficult to reconcile with the emerging scenario in which the lobes of FR I and FR II radio galaxies have vastly different energy budgets. However, a combination of lower density environment, spectral aging and strong shocks driven by powerful FR II radio galaxies may reduce the radiative efficiency of these objects relative to FR Is and counteract, to some extent, the higher radiative efficiency expected to arise due to the lower fraction of energy in non-radiating particles. An unexpected corollary is that extrapolating the Q{sub jet}-L{sub radio} relation determined for low power FR I radio galaxies provides a reasonable approximation for high power sources, despite their apparently different lobe compositions.

  19. Evaluation of water and energy budgets in regional climate models applied over Europe

    Energy Technology Data Exchange (ETDEWEB)

    Hagemann, S.; Jacob, D. [Max Planck Institute for Meteorology, Hamburg (Germany); Machenhauer, B.; Christensen, O.B. [Danish Meteorological Institute, Climate Research Division, Copenhagen Oe (Denmark); Jones, R. [Meteorological Office Hadley Centre, Bracknell (United Kingdom); Deque, M. [Meteo-France CNRM/GMGEC/EAC, Toulouse Cedex 01 (France); Vidale, P.L. [Climate Research ETH, Zuerich (Switzerland)

    2004-10-01

    This study presents a model intercomparison of four regional climate models (RCMs) and one variable resolution atmospheric general circulation model (AGCM) applied over Europe with special focus on the hydrological cycle and the surface energy budget. The models simulated the 15 years from 1979 to 1993 by using quasi-observed boundary conditions derived from ECMWF re-analyses (ERA). The model intercomparison focuses on two large atchments representing two different climate conditions covering two areas of major research interest within Europe. The first is the Danube catchment which represents a continental climate dominated by advection from the surrounding land areas. It is used to analyse the common model error of a too dry and too warm simulation of the summertime climate of southeastern Europe. This summer warming and drying problem is seen in many RCMs, and to a less extent in GCMs. The second area is the Baltic Sea catchment which represents maritime climate dominated by advection from the ocean and from the Baltic Sea. This catchment is a research area of many studies within Europe and also covered by the BALTEX program. The observed data used are monthly mean surface air temperature, precipitation and river discharge. For all models, these are used to estimate mean monthly biases of all components of the hydrological cycle over land. In addition, the mean monthly deviations of the surface energy fluxes from ERA data are computed. Atmospheric moisture fluxes from ERA are compared with those of one model to provide an independent estimate of the convergence bias derived from the observed data. These help to add weight to some of the inferred estimates and explain some of the discrepancies between them. An evaluation of these biases and deviations suggests possible sources of error in each of the models. For the Danube catchment, systematic errors in the dynamics cause the prominent summer drying problem for three of the RCMs, while for the fourth RCM this is

  20. Heat Fluxes and River Energy Budget on the Example of Lowland Świder River

    Directory of Open Access Journals (Sweden)

    Łaszewski Maksym

    2015-03-01

    Full Text Available The paper present the energy budget of the downstream part of lowland Świder River, right tributary of the Vistula River in Mazovian Lowland, Poland. Heat fluxes were calculated on the example of four days, representing different meteorological and vegetative conditions. Results confirmed the dominant role of radiation, which accounted for an average of 90.7% and 79.7% gains and losses of thermal energy. Participation of non-radiative components proved to be far less crucial; the average contribution of condensation, sensible heat transfer, bed conduction and friction in energy gains accounted respectively to 0.0%, 0.6%, 2.9% and 5.9%, while the average contribution of evaporation, sensible heat transfer and bed conduction in energy losses reached respectively 4.5%, 1.1% and 14.6%. The results showed significant effect of riparian vegetation and cloud cover on river heat fluxes

  1. Transition of surface energy budget in the Gobi Desert between spring and summer seasons

    Science.gov (United States)

    Smith, Eric A.; Reiter, Elmar R.; Gao, Youxi

    1986-01-01

    The surface energetics of the southwest Gobi Desert, including the temporal variations and diurnally averaged properties of the surface energy budget components, was investigated. The field program was conducted during the spring and summer of 1984, with the measurement system designed to monitor radiative exchange, heat/moisture storage in the soil, and sensible and latent heat exhange between the ground and the atmosphere. Results of the analysis reveal a seasonal transition feature not expected of a midlatitude desert. Namely, the differences in both surface radiation exchange and the distibution of sensible and latent heat transfer arise within a radiatively forced environment that barely deviates from spring to summer in terms of available solar energy at the surface. Both similarities and differences in the spring and summer surface energy budgets arise from differences imparted to the system by an increase in the summertime atmospheric moisture content. Changes in the near-surface mixing ratio are shown to alter the effectiveness of the desert surface in absorbing radiative energy and redistibuting it to the lower atmosphere through sensible and latent heat exchange.

  2. Estimating Ionosphere-Thermosphere Energy Budget: the ICME Storm of 16-19 March 2013

    Science.gov (United States)

    Verkhoglyadova, O. P.; Meng, X.; Mannucci, A. J.; Mlynczak, M. G.; Hunt, L. A.; Lu, G.

    2016-12-01

    The ionosphere-thermosphere (IT) energy budget for the ICME storm of 16-19 March 2013 is estimated with the Global Ionosphere-Thermosphere Model (GITM), empirical models and observation-derived proxies. GITM is used to analyze the IT energy partitioning in detail, with a focus on auroral heating, Joule heating and thermospheric cooling. Solar wind data, F10.7, OVATION Prime and the Weimer 2005 model are used to drive GITM from above. Thermospheric nitric oxide and carbon dioxide cooling emission powers and fluxes are estimated from TIMED/SABER measurements. AMIE estimations of hemispheric power and Joule heating are presented, based on data from global magnetometers, the AMPERE magnetic field data, SSUSI auroral images and the SuperDARN radar network. Additionally, we inter-compare selected energy channels for five CME-type and eight HSS-type storms modeled with GITM and TIEGCM. We discuss challenges and discrepancies in estimating and modeling the IT energy budget, especially Joule heating, during geomagnetic storms.

  3. Revised congressional budget request, FY 1982. Conservation and renewable energy program

    Energy Technology Data Exchange (ETDEWEB)

    1981-03-01

    Programs dealing with conservation and renewable energy are reprinted from the Revised Congressional Budget Request FY 1982. From Volume 7, Energy Conservation, information is presented on: buildings and community systems; industrial programs; transportation programs; state and local programs; inventor's program energy conversion technology; energy impact assistance; and residential/commercial retrofit. From Volume 2, Energy Supply Research and Development, information and data are presented on: solar building applications; solar industrial applications; solar power applications; solar information systems; SERI facility; solar international activities; alcohol fuels; geothermal; and hydropower. From Volume 6, Energy Production, Demonstration, and Distribution, information and data on solar energy production, demonstration, and distribution are presented. From Volume 3, Energy Supply and R and D Appropriation, information and data on electric energy systems and energy storage systems are included. From Volume 4, information and data are included on geothermal resources development fund. In Volume 5, Power Marketing Administrations, information and data are presented on estimates by appropriations, positions and staff years by appropriation, staffing distribution, and power marketing administrations. Recissions and deferrals for FY 1981 are given. (MCW)

  4. Dynamics Analysis of Wind Energy Production Development

    Science.gov (United States)

    Berg, V. I.; Zakirzakov, A. G.; Gordievskaya, E. F.

    2017-01-01

    The paper presents the analysis of the introduction experience and dynamics development of the world wind energy production. Calculated the amount of wind energy sources investments and the production capacity growth dynamics of the wind turbines. The studies have shown that the introduction dynamics of new wind energy sources is higher than any other energy source.

  5. Magnetic Energy and Helicity Budgets in the Active-Region Solar Corona. I. Linear Force-Free Approximation

    CERN Document Server

    Georgoulis, M K

    2007-01-01

    We self-consistently derive the magnetic energy and relative magnetic helicity budgets of a three-dimensional linear force-free magnetic structure rooted in a lower boundary plane. For the potential magnetic energy we derive a general expression that gives results practically equivalent to those of the magnetic Virial theorem. All magnetic energy and helicity budgets are formulated in terms of surface integrals applied to the lower boundary, thus avoiding computationally intensive three-dimensional magnetic field extrapolations. We analytically and numerically connect our derivations with classical expressions for the magnetic energy and helicity, thus presenting a so-far lacking unified treatment of the energy/helicity budgets in the constant-alpha approximation. Applying our derivations to photospheric vector magnetograms of an eruptive and a noneruptive solar active regions, we find that the most profound quantitative difference between these regions lies in the estimated free magnetic energy and relative ...

  6. The May October energy budget of a Scots pine plantation at Hartheim, Germany

    Science.gov (United States)

    Gay, L. W.; Vogt, R.; Kessler, A.

    1996-03-01

    This paper describes measurements of the Hartheim forest energy budget for the 157-day period of May 11 Oct. 14, 1992. Data were collected as 30-min means. Energy available to the forest was measured with net radiometers and soil heat flux discs; sensible heat exchange between the canopy and atmosphere was measured with two “One-Propeller Eddy Correlation” (OPEC) systems, and latent energy (evapotranspiration or ET) was determined as a residual in the surface energy balance equation. Net rediation, change in thermal storage, and sensible heat flux were verified by independent measurements during the Hartheim Experiment (HartX, May 11 12), and again during the “HartX2” experiment over 20 days late in the summer (Sep. 10 29). Specifically, sensible heat estimates from the two adjacent OPEC sensor sets were in close agreement throughout the summer, and in excellent agreement with measurements of sonic eddy correlation systems in May and September. The eddy correlation/energy balance technique was observed to overestimate occurrence of dew, leading to an underestimate of daily ET of about 5%. After taking dew into account, estimates of OPEC ET totaled 358 mm over the 5.1-month period, which is in quite good agreement with an ET estimate of 328 mm from a hydrologic water balance. An observed decrease in forest ET in July and August was clearly associated with low rainfall and increased soil water deficit. The OPEC system required only modest technical supervision, and generated a data yield of 99.5% over the period DOY 144 288. The documented verification and precision of this energy budget appears to be unmatched by any other long-term forest study reported to date.

  7. Analysis of Water and Energy Budgets and Trends Using the NLDAS Monthly Data Products

    Science.gov (United States)

    Vollmer, B.; Rui, H.; Mocko, D. M.; Teng, W. L.; Lei, G.

    2012-12-01

    The North American Land Data Assimilation System (NLDAS, http://ldas.gsfc.nasa.gov/nldas/) data set, with high spatial and temporal resolutions (0.125° x 0.125°, hourly and monthly), long temporal coverage (Jan. 1979 - present), and various water- and energy-related variables (precipitation, soil moisture, evapotranspiration, radiation, latent heat, and runoff, etc.), is an excellent data source for supporting water and energy cycle studies. NLDAS hourly data, accessible from NASA Goddard Earth Sciences Data and Information Services Center (GES DISC; Hydrology Data Holdings Portal http://disc.sci.gsfc.nasa.gov/hydrology/data-holdings), have been broadly used by various user communities in modeling, research, and applications, such as drought and flood monitoring, watershed and water quality management, and case studies for extreme events. NLDAS data sets consist of a Forcing data set for land surface models, comprising a synthesis of best available near-surface observations and reanalyses, and separate land surface model output data sets of NLDAS models driven by the Forcing. To further facilitate analysis of water and energy budgets and trends, NLDAS monthly data products have been recently released by NASA GES DISC. The NLDAS monthly data were generated from NLDAS hourly data, as monthly accumulation for precipitation and monthly average for other variables. NLDAS monthly climatology data set will further be generated based on the monthly data and become accessible also from the Hydrology Data Holdings Portal. This presentation describes the major characteristics of the NLDAS data set. Some preliminary analysis results of water and energy budgets and trends from the NLDAS monthly data are shown and discussed. The NLDAS hourly, monthly, and monthly climatology terrestrial hydrological data could play an important role in characterizing the spatial and temporal variability of water and energy cycles and, thereby, improve our understanding of land

  8. Reconciled climate response estimates from climate models and the energy budget of Earth

    Science.gov (United States)

    Richardson, Mark; Cowtan, Kevin; Hawkins, Ed; Stolpe, Martin B.

    2016-10-01

    Climate risks increase with mean global temperature, so knowledge about the amount of future global warming should better inform risk assessments for policymakers. Expected near-term warming is encapsulated by the transient climate response (TCR), formally defined as the warming following 70 years of 1% per year increases in atmospheric CO2 concentration, by which point atmospheric CO2 has doubled. Studies based on Earth's historical energy budget have typically estimated lower values of TCR than climate models, suggesting that some models could overestimate future warming. However, energy-budget estimates rely on historical temperature records that are geographically incomplete and blend air temperatures over land and sea ice with water temperatures over open oceans. We show that there is no evidence that climate models overestimate TCR when their output is processed in the same way as the HadCRUT4 observation-based temperature record. Models suggest that air-temperature warming is 24% greater than observed by HadCRUT4 over 1861-2009 because slower-warming regions are preferentially sampled and water warms less than air. Correcting for these biases and accounting for wider uncertainties in radiative forcing based on recent evidence, we infer an observation-based best estimate for TCR of 1.66 °C, with a 5-95% range of 1.0-3.3 °C, consistent with the climate models considered in the IPCC 5th Assessment Report.

  9. An energy-budget-based glacier melting model for the Tibetan Plateau

    Science.gov (United States)

    Ding, Baohong; Yang, Kun; Chen, Yingying

    2013-04-01

    There have been rapid glacier retreats during the past few decades on the Tibetan Plateau, which not only have far-reaching impacts on the water resources in this region, but also potentially threat the downstream by glacial lake outburst floods. It is therefore important to model the physical link between glacier melting and climate changes and its implication in water resources. There have been a few studies on glacier melting models, of which the applicability is limited to some areas and the simulation capability also needs to be improved. This paper presents a new energy-budget-based model for the melting of the mountainous glaciers. Enthalpy, rather than temperature, is used in the energy balance equations to simplify the computation for the energy transfer through water phase transition and within-snow liquid water movement. Heat transfer is computed in both snow and ice layers, and the inhomogeneous layering method is employed to describe the temperature profiles better, especially at the interface between snow and atmosphere as well as that between snow and ice. A new parameterization scheme is introduced into the model to calculate turbulent heat transfer over glacier surfaces. This model was validated based on the data collected from a field experiment which was implemented in the melting zone of the Parlung No. 4 Glacier in the southeastern TP from May to August in 2009. The result shows that the RMSE of the simulated hourly surface temperature is about 0.97 degree centigrade and the R2 is 0.81. The RMSE of the simulated hourly latent heat flux and hourly sensible heat flux are 14.5W m^-2 and 23.5W m^-2 respectively, and R2 are 0.92 and 0.93. In general, this energy-budget-based model could reasonably simulate the glacier melting process. The model is still under development for a better simulation of the glacier melting and its contribution to the water resources.

  10. Regional energy budget control of the intertropical convergence zone and application to mid-Holocene rainfall

    Science.gov (United States)

    Boos, William R.; Korty, Robert L.

    2016-12-01

    Shifts in the latitude of the intertropical convergence zone--a region of intense tropical rainfall--have often been explained through changes in the atmospheric energy budget, specifically through theories that tie rainfall to meridional energy fluxes. These quantitative theories can explain shifts in the zonal mean, but often have limited relevance for regional climate shifts, such as a period of enhanced precipitation over Saharan Africa during the mid-Holocene. Here we present a theory for regional tropical rainfall shifts that utilizes both zonal and meridional energy fluxes. We first identify a qualitative link between zonal and meridional energy fluxes and rainfall variations associated with the seasonal cycle and the El Niño/Southern Oscillation. We then develop a quantitative theory based on these fluxes that relates atmospheric energy transport to tropical rainfall. When applied to the orbital configuration of the mid-Holocene, our theory predicts continental rainfall shifts over Africa and Southeast Asia that are consistent with complex model simulations. However, the predicted rainfall over the Sahara is not sufficient to sustain vegetation at a level seen in the palaeo-record, which instead requires an additional large energy source such as that due to reductions in Saharan surface albedo. We thus conclude that additional feedbacks, such as those involving changes in vegetation or soil type, are required to explain changes in rainfall over Africa during the mid-Holocene.

  11. A 19-year long energy budget of an upland peat bog, northern England

    Science.gov (United States)

    Worrall, Fred; Clay, Gareth; Moody, Catherine; Burt, Timothy

    2015-04-01

    This study has estimated the long term evaporation record for a peat covered catchment in northern England. In this study, 19 years of daily evaporation were estimated for rain-free periods using White's methods. Net radiation was measured over the study period; soil heat flux was calculated from temperature profiles; and sensible heat flux was calculated assuming the energy budget was closed. The calculated time series was compared to available environmental information on the same time step and over the same time period. Over a 19-year period it was possible to calculate 1662 daily evaporation rates (26% of the period). The study showed that the energy flux to net primary productivity was a small, long-term sink of energy but this sink was a virtue of high carbon accumulation in peat catchments: in catchments where there is no long-term dry matter accumulation, net primary productivity must be a small net source of energy. The study showed that evaporation increased over the study period whilst sensible heat flux significantly declined with the ecosystem became a stronger heat sink reflecting an increased use of sensible heat energy to meet evaporative demand. The relatively small change in evaporative flux compared to other energy fluxes suggests that this system is a "near-equilibrium" system and not a "far-from-equilibrium" system.

  12. Comparison of energy-budget evaporation losses from two morphometrically different Florida seepage lakes

    Science.gov (United States)

    Sacks, L.A.; Lee, T.M.; Radell, M.J.

    1994-01-01

    Evaporation was computed by the energy-budget method for two north Florida lakes with similar surface areas but different depths, for the period May 1989 to December 1990. Lake Barco, in north-central Florida, is shallow, with an average depth of 3 m; Lake Five-O, in the Florida panhandle, is considerably deeper, with an average depth of 9.5 m. As a result, the thermal regime and seasonal evaporation rates of the lakes are different. Evaporation from the shallower lake was higher than that from the deeper lake in the winter and spring. In the late summer and autumn, however, the situation is reversed. Evaporation from the shallow lake is directly related to the amount of incoming shortwave radiation because of its limited ability to store energy. The lag in evaporation at the deeper lake is a function of the greater amount of heat that it seasonally stores and releases. The difference in annual evaporation between Lake Barco (151 cm year-1) and Lake Five-O (128 cm year-1) is related to differences in regional climatic conditions between the two sites. Additionally, higher than normal evaporation rates at the two lakes are probably related to drought conditions experienced in north Florida during 1990, which resulted in higher temperatures and more incoming radiation. Monthly evaporation at Lake Barco could usually be estimated within 10% of the energy-budget evaporation using a constant pan coefficient. This lake may be representative of other shallow lakes that do not store considerable heat. Monthly evaporation at Lake Five-O, however, could not be estimated accurately by using an annual pan coefficient because of the large seasonal influence of change in stored heat. Monthly mass-transfer evaporation compared well with energy-budget evaporation at Lake Barco, but did not compare well at Lake Five-O. These errors may also be associated with changes in heat storage. Thus, the thermal regime of the lake must be considered to estimate accurately the seasonal

  13. Energy budget of the volcano Stromboli, Italy. [Power potential of 100- to 1000 MW

    Energy Technology Data Exchange (ETDEWEB)

    McGetchin, T.; Chouet, B.A.

    1976-03-01

    Data from eruption movies are used to construct a budget among various modes of energy transport for the volcano Stromboli. In its normal steady state eruption mode, Stromboli delivers approximately 1.1 MW of power to the surface by energy transport mechanisms other than conduction; conducted heat probably is of the order of 6 mW (for the part of the volcano above sea level). Of this 1.1 mW, approximately 60 percent of the eruption energy is carried in the thermal energy of ejected gas; approximately 20 percent by the thermal energy of ejected lava, and 20 percent by radiative heat transfer from the open vent. Energy transported in kinetic energy of the gas seismic energy and jet noise of acoustical energy is trivial. The probable thermal reserve of Stromboli could be quite large, perhaps sufficient to produce power in the 100- to 1000-MW range provided engineering capability existed to exploit it. The abundance of gas in the eruption medium implies that Stromboli is probably open to sea water. A simple model accounting for the observations and apparent flux of water into the magma yields an average apparent permeability of the volcano in the submicrodarcy range, very low values. These model values may reflect actual average permeabilities or exceedingly low permeability locally, such as near the vent itself. The model suggests that the bulk of the water would enter at the base of the volcanic pile. If so, this might account for the episodic geyser-like behavior of the volcano which may reflect a convective instability associated with influx of water.

  14. Turbulence Kinetic Energy budget during the afternoon transition – Part 2: A simple TKE model

    Directory of Open Access Journals (Sweden)

    E. Nilsson

    2015-11-01

    Full Text Available A simple model for turbulence kinetic energy (TKE and the TKE budget is presented for sheared convective atmospheric conditions based on observations from the Boundary Layer Late Afternoon and Sunset Turbulence (BLLAST field campaign. It is based on an idealized mixed-layer approximation and a simplified near-surface TKE budget. In this model, the TKE is dependent on four budget terms (turbulent dissipation rate, buoyancy production, shear production and vertical transport of TKE and only requires measurements of three input available (near-surface buoyancy flux, boundary layer depth and wind speed at one height in the surface layer. This simple model is shown to reproduce some of the observed variations between the different studied days in terms of near-surface TKE and its decay during the afternoon transition reasonably well. It is subsequently used to systematically study the effects of buoyancy and shear on TKE evolution using idealized constant and time-varying winds during the afternoon transition. From this, we conclude that many different TKE decay rates are possible under time-varying winds and that generalizing the decay with simple scaling laws for near-surface TKE of the form tα may be questionable. The model's errors result from the exclusion of processes such as elevated shear production and horizontal advection. The model also produces an overly rapid decay of shear production with height. However, the most influential budget terms governing near-surface TKE in the observed sheared convective boundary layers are included, while only second order factors are neglected. Comparison between modeled and averaged observed estimates of dissipation rate illustrate that the overall behavior of the model is often quite reasonable. Therefore, we use the model to discuss the low turbulence conditions that form first in the upper parts of the boundary layer during the afternoon transition and are only apparent later near the surface. This

  15. The terms of turbulent kinetic energy budget within random arrays of emergent cylinders

    Science.gov (United States)

    Ricardo, Ana M.; Koll, Katinka; Franca, Mário J.; Schleiss, Anton J.; Ferreira, Rui M. L.

    2014-05-01

    This article is aimed at quantifying and discussing the relative magnitude of key terms of the equation of conservation of turbulent kinetic energy (TKE) in the inter-stem space of a flow within arrays of vertical cylinders simulating plant stems of emergent and rigid vegetation. The spatial distribution of turbulent quantities and mean flow variables are influenced by two fundamental space scales, the diameter of the stems and the local stem areal number-density. Both may vary considerably since the areal distribution of plant stems in natural systems is generally not homogeneous; they are often arranged in alternating sparse and dense patches. The magnitude of the terms of the budget of TKE in the inter-stem space has seldom been quantified experimentally and is currently not well known. This work addresses this research need. New databases, consisting of three-component LDA velocity series and two-component PIV velocity maps, obtained in carefully controlled laboratory conditions, were used to calculate the terms of the TKE budget. The physical system comprises random arrays of rigid and emergent cylinders with longitudinally varying areal number-density. It is verified that the main source of TKE is vortex shedding from individual cylinders. The rates of production and dissipation are not in equilibrium. Regions with negative production, a previously unreported feature, are identified. Turbulent transport is particularly important along the von Kármán vortex street. Convective rate of change of TKE and pressure diffusion are most relevant in the vicinity of the cylinders.

  16. Arctic energy budget in relation to sea-ice variability on monthly to annual time scales

    Science.gov (United States)

    Krikken, Folmer; Hazeleger, Wilco

    2015-04-01

    The strong decrease in Arctic sea-ice in recent years has triggered a strong interest in Arctic sea-ice predictions on seasonal to decadal time scales. Hence, it is key to understand physical processes that provide enhanced predictability beyond persistence of sea ice anomalies. The authors report on an analysis of natural variability of Arctic sea-ice from an energy budget perspective, using 15 CMIP5 climate models, and comparing these results to atmospheric and oceanic reanalyses data. We quantify the persistence of sea ice anomalies and the cross-correlation with the surface and top energy budget components. The Arctic energy balance components primarily indicate the important role of the seasonal sea-ice albedo feedback, in which sea-ice anomalies in the melt season reemerge in the growth season. This is a robust anomaly reemergence mechanism among all 15 climate models. The role of ocean lies mainly in storing heat content anomalies in spring, and releasing them in autumn. Ocean heat flux variations only play a minor role. The role of clouds is further investigated. We demonstrate that there is no direct atmospheric response of clouds to spring sea-ice anomalies, but a delayed response is evident in autumn. Hence, there is no cloud-ice feedback in late spring and summer, but there is a cloud-ice feedback in autumn, which strengthens the ice-albedo feedback. Anomalies in insolation are positively correlated with sea-ice variability. This is primarily a result of reduced multiple-reflection of insolation due to an albedo decrease. This effect counteracts the sea-ice albedo effect up to 50%. ERA-Interim and ORAS4 confirm the main findings from the climate models.

  17. A New Optimization via Simulation Approach for Dynamic Facility Layout Problem with Budget Constraints

    Directory of Open Access Journals (Sweden)

    Parham Azimi

    2012-01-01

    Full Text Available A new efficient heuristic algorithm has been developed for the dynamic facility layout problem with budget constraint (DFLPB using optimization via simulation technique. The heuristic integrates integer programming and discrete event simulation to address DFLPB. In the proposed algorithm, the nonlinear model of the DFLP has been changed to a pure integer programming (PIP model. Then, the optimal solution of the PIP model has been used in a simulation model that has been designed in a similar manner as the DFLP for determining the probability of assigning a facility to a location. After a sufficient number of runs, the simulation model obtains near optimum solutions. Finally, to test the performance of the algorithm, several test problems have been taken from the literature and solved. The results show that the proposed algorithm is more efficient in terms of speed and accuracy than other heuristic algorithms presented in previous works.

  18. Budget projections - 1991 through 1996 for research in high energy physics

    Energy Technology Data Exchange (ETDEWEB)

    1991-05-01

    This research program in high energy physics is carried out under the general supervision of a committee which is composed of G.W. Brandenburg, G.J. Feldman, M.E. Franklin, R.J. Glauber, K. Kinoshita, F.M. Pipkin, K. Strauch, R. Wilson, and H. Yamamoto. Professor G.J. Feldman currently serves as chair of this committee. Dr. Brandenburg is the Director of the High Energy Physics Laboratory and administers the DOE high energy physics contract. In the fall of 1991 S. Mishra will join this committee. Harvard is planning to make one or two additional senior faculty appointments in experimental high energy physics over the next two years. The principal goals of the work described here are to carry out forefront programs in high energy physics research and to provide first rate educational opportunities for students. The experimental program supported through HEPL is carried out at the major accelerator centers in the world and addresses some of the most important questions in high energy physics. Harvard`s educational efforts are concentrated in graduate education, where they are currently supporting thirteen research students. In addition, undergraduate students work in projects at HEPL during the academic year and over summers. These budget projections cover all of the Harvard based high energy physics experimental activities. The {open_quotes}umbrella{close_quotes} nature of this contract greatly simplifies support of essential central technical and computer services and helps the group to take advantage of new physics opportunities and to respond to unexpected needs. The funding for the operation of the HEPL facility is shared proportionally by the experimental groups. Harvard financially supports this high energy physics research program in many ways.

  19. Seasonal variation in body mass and energy budget in Chinese bulbuls (pycnonotus sinensis)

    Institute of Scientific and Technical Information of China (English)

    Mengsi Wu; Yuchao Xiao; Fang Yang; Limeng Zhou; Weihong Zheng; Jinsong Liu

    2014-01-01

    Background:Seasonal adjustments in body mass and energy budget are important for the survival of small birds in temperate zones. Seasonal changes in body mass, body temperature, gross energy intake (GEI), digestible energy intake (DEI), body fat content, as well as length and mass of the digestive tract, were measured in Chinese Bulbuls (Pycnonotus sinensis) caught in the wild at Wenzhou, China. Methods:Body mass was determined with a Sartorius balance. The caloric contents of the dried food and feces were then determined using a oxygen bomb calorimeter. Total fat was extracted from the dried carcasses by ether extraction in a Soxhlet apparatus. The digestive tract of each bird was measured and weighed, and was then dried to a constant mass. Results:Body mass showed a significant seasonal variation and was higher in spring and winter than in summer and autumn. Body fat was higher in winter than in other seasons. GEI and DEI were significantly higher in winter. The length and mass of the digestive tract were greatest in winter and the magnitude of both these parameters was positively correlated with body mass, GEI and DEI. Small passerines typical y have higher daily energy expenditure in winter, necessitating increased food consumption. Conclusions:This general observation is consistent with the observed winter increase in gut volume and body mass in Chinese Bulbuls. These results suggest that Chinese Bulbuls adjust to winter conditions by increasing their body mass, body fat, GEI, DEI and digestive tract size.

  20. Seasonal variation in body mass and energy budget in Chinese bulbuls (pycnonotus sinensis)

    Institute of Scientific and Technical Information of China (English)

    Mengsi; Wu; Yuchao; Xiao; Fang; Yang; Limeng; Zhou; Weihong; Zheng; Jinsong; Liu

    2014-01-01

    Background: Seasonal adjustments in body mass and energy budget are important for the survival of small birds in temperate zones. Seasonal changes in body mass, body temperature, gross energy intake(GEI), digestible energy intake(DEI), body fat content, as well as length and mass of the digestive tract, were measured in Chinese Bulbuls(Pycnonotus sinensis) caught in the wild at Wenzhou, China.Methods: Body mass was determined with a Sartorius balance. The caloric contents of the dried food and feces were then determined using a oxygen bomb calorimeter. Total fat was extracted from the dried carcasses by ether extraction in a Soxhlet apparatus. The digestive tract of each bird was measured and weighed, and was then dried to a constant mass.Results: Body mass showed a significant seasonal variation and was higher in spring and winter than in summer and autumn. Body fat was higher in winter than in other seasons. GEI and DEI were significantly higher in winter.The length and mass of the digestive tract were greatest in winter and the magnitude of both these parameters was positively correlated with body mass, GEI and DEI. Small passerines typically have higher daily energy expenditure in winter, necessitating increased food consumption.Conclusions: This general observation is consistent with the observed winter increase in gut volume and body mass in Chinese Bulbuls. These results suggest that Chinese Bulbuls adjust to winter conditions by increasing their body mass, body fat, GEI, DEI and digestive tract size.

  1. Analysis of Water and Energy Budgets and Trends Using the NLDAS Monthly Data Sets

    Science.gov (United States)

    Vollmer, Bruce E.; Rui, Hualan; Mocko, David M.; Teng, William L.; Lei, Guang-Dih

    2012-01-01

    The North American Land Data Assimilation System (NLDAS) is a collaborative project between NASA GSFC, NOAA, Princeton University, and the University of Washington. NLDAS has created surface meteorological forcing data sets using the best-available observations and reanalyses. The forcing data sets are used to drive four separate land-surface models (LSMs), Mosaic, Noah, VIC, and SAC, to produce data sets of soil moisture, snow, runoff, and surface fluxes. NLDAS hourly data, accessible from the NASA GES DISC Hydrology Data Holdings Portal, http://disc.sci.gsfc.nasa.gov/hydrology/data-holdings, are widely used by various user communities in modeling, research, and applications, such as drought and flood monitoring, watershed and water quality management, and case studies of extreme events. More information is available at http://ldas.gsfc.nasa.gov/. To further facilitate analysis of water and energy budgets and trends, NLDAS monthly data sets have been recently released by NASA GES DISC.

  2. Energy budget closure and field scale estimation of canopy energy storage with increased and sustained turbulence

    Science.gov (United States)

    Anderson, R. G.; Wang, D.

    2012-12-01

    Eddy Covariance (EC) is widely used for direct, non-invasive observations of land-atmosphere energy and mass fluxes. However, EC observations of available energy fluxes are usually less than fluxes inferred from radiometer and soil heat flux observations; thus introducing additional uncertainty in using and interpreting EC flux measurements. We compare EC observations from two towers established over sugarcane (Saccharum officinarum L.) in Hawai'i, USA under similar cultivation, temperature, sunlight, and precipitation, but drastically different wind conditions due to orographic effects. At a daily scale, we find that energy closure for both towers occurs on days when the entire 24 hours has sufficient turbulence. At our windier site, this turbulence condition occurs over 60% of the time, which contributes to substantially better daily energy closure (~98%) than at the calmer site (~75%). At our windy site, we then invert the daily energy closure for continuously windy days to calculate canopy energy storage. At full canopy, peak daily canopy energy storage fluxes (200-400 Wm-2) are approximately an order of magnitude larger than soil heat flux (20-40 Wm-2). As a fraction of net radiation, canopy energy storage appears to vary seasonally and shows substantially greater variability than soil heat flux. The results illustrate the importance of sustained turbulence for accurate, direct measurement of land-atmosphere fluxes. As increasing number of EC towers are established in complex terrain, these results indicate the need for preliminary wind studies to optimize tower placement where orography enhances, rather than suppresses, turbulence.

  3. Energy budget closure and field scale estimation of canopy energy storage with increased and sustained turbulence

    Science.gov (United States)

    Eddy Covariance (EC) is widely used for direct, non-invasive observations of land-atmosphere energy and mass fluxes. However, EC observations of available energy fluxes are usually less than fluxes inferred from radiometer and soil heat flux observations; thus introducing additional uncertainty in u...

  4. Guide to reducing energy use. budget costs. Volume II. Local energy management program

    Energy Technology Data Exchange (ETDEWEB)

    Brooks, S O; Wood, E S; Guenther, S; Graves, T

    1979-10-01

    Information is presented to aid communities tailor an energy conservation program specifically to themselves. Existing and new buildings, procurement, employee transportation programs, street lighting systems, and energy resource recovery are discussed. Examples are given on what can and has been done in communities. (MCW)

  5. An individual-based model of zebrafish population dynamics accounting for energy dynamics.

    Directory of Open Access Journals (Sweden)

    Rémy Beaudouin

    Full Text Available Developing population dynamics models for zebrafish is crucial in order to extrapolate from toxicity data measured at the organism level to biological levels relevant to support and enhance ecological risk assessment. To achieve this, a dynamic energy budget for individual zebrafish (DEB model was coupled to an individual based model of zebrafish population dynamics (IBM model. Next, we fitted the DEB model to new experimental data on zebrafish growth and reproduction thus improving existing models. We further analysed the DEB-model and DEB-IBM using a sensitivity analysis. Finally, the predictions of the DEB-IBM were compared to existing observations on natural zebrafish populations and the predicted population dynamics are realistic. While our zebrafish DEB-IBM model can still be improved by acquiring new experimental data on the most uncertain processes (e.g. survival or feeding, it can already serve to predict the impact of compounds at the population level.

  6. Wave breaking on turbulent energy budget in the ocean surface mixed layer

    Institute of Scientific and Technical Information of China (English)

    SUN Qun; GUAN Changlong; SONG Jinbao

    2008-01-01

    As an important physical process at the air-sea interface.wave movement and breaking have a significant effect on the ocean surface mixed layer (OSML).When breaking waves occur at the ocean surface,turbulent kinetic energy (TKE) is input downwards,and a sublayer is formed near the surface and turbulence vertical mixing is intensively enhanced.A one-dimensional ocean model including the Mellor-Yamada level 2.5 turbulence closure equations was employed in our research on variations in turbulent energy budget wimin OSML.The influence of wave breaking could be introduced into the model by modifying an existing surface boundary condition of the TKE equation and specifying its input.The vertical diffusion and dissipation of TKE were effectively enhanced in the sublayer when wave breaking was considered.Turbulent energy dissipated in the sublayer was about 92.0% of the total depth-integrated dissipated TKE,which is twice higher than that of non-wave breaking.The shear production of TKE decreased bv 3.5% because the mean flow fields tended to be uniform due to wave-enhanced turbulent mixing.As a result.a new local equilibrium between diffusion and dissipation of TKE was reached in the wave-enhanced layer.Below the sublayer,the local equilibrium between shear production and dissipation of TKE agreed with the conclusion drawn from the classical law-of-the-wall (Craig and Banner,1994).

  7. Radiative Energy Budgets of Phototrophic Surface-Associated Microbial Communities and their Photosynthetic Efficiency Under Diffuse and Collimated Light

    Science.gov (United States)

    Lichtenberg, Mads; Brodersen, Kasper E.; Kühl, Michael

    2017-01-01

    We investigated the radiative energy budgets of a heterogeneous photosynthetic coral reef sediment and a compact uniform cyanobacterial biofilm on top of coastal sediment. By combining electrochemical, thermocouple and fiber-optic microsensor measurements of O2, temperature and light, we could calculate the proportion of the absorbed light energy that was either dissipated as heat or conserved by photosynthesis. We show, across a range of different incident light regimes, that such radiative energy budgets are highly dominated by heat dissipation constituting up to 99.5% of the absorbed light energy. Highest photosynthetic energy conservation efficiency was found in the coral sediment under low light conditions and amounted to 18.1% of the absorbed light energy. Additionally, the effect of light directionality, i.e., diffuse or collimated light, on energy conversion efficiency was tested on the two surface-associated systems. The effects of light directionality on the radiative energy budgets of these phototrophic communities were not unanimous but, resulted in local spatial differences in heat-transfer, gross photosynthesis, and light distribution. The light acclimation index, Ek, i.e., the irradiance at the onset of saturation of photosynthesis, was >2 times higher in the coral sediment compared to the biofilm and changed the pattern of photosynthetic energy conservation under light-limiting conditions. At moderate to high incident irradiances, the photosynthetic conservation of absorbed energy was highest in collimated light; a tendency that changed in the biofilm under sub-saturating incident irradiances, where higher photosynthetic efficiencies were observed under diffuse light. The aim was to investigate how the physical structure and light propagation affected energy budgets and light utilization efficiencies in loosely organized vs. compact phototrophic sediment under diffuse and collimated light. Our results suggest that the optical properties and the

  8. Variation in energy expenditure among black-legged kittiwakes : Effects of activity-specific metabolic rates and activity budgets

    NARCIS (Netherlands)

    Jodice, PGR; Roby, DD; Suryan, RM; Irons, DB; Kaufman, AM; Turco, KR; Visser, GH

    2003-01-01

    We sought to determine the effect of variation in time-activity budgets (TABs) and foraging behavior on energy expenditure rates of parent black-legged kittiwakes (Rissa tridactyla). We quantified TABs using direct observations of radio-tagged adults and simultaneously measured field metabolic rates

  9. Micrometeorological data for energy-budget studies near Rogers Spring, Ash Meadows National Wildlife Refuge, Nye County, Nevada, 1994

    Energy Technology Data Exchange (ETDEWEB)

    Nichols, W.D.; Rapp, T.R.

    1996-05-01

    The data were collected at two sites near Rogers Spring for use in energy-budget studies beginning in 1994. The data collected at each site included net radiation, air temperature at two heights, dew- point temperature at two heights, windspeed at two heights, soil heat flux, and soil temperature in the interval between the land surface and the buried heat-flux plates.

  10. Revisiting the global surface energy budgets with maximum-entropy-production model of surface heat fluxes

    Science.gov (United States)

    Huang, Shih-Yu; Deng, Yi; Wang, Jingfeng

    2016-10-01

    The maximum-entropy-production (MEP) model of surface heat fluxes, based on contemporary non-equilibrium thermodynamics, information theory, and atmospheric turbulence theory, is used to re-estimate the global surface heat fluxes. The MEP model predicted surface fluxes automatically balance the surface energy budgets at all time and space scales without the explicit use of near-surface temperature and moisture gradient, wind speed and surface roughness data. The new MEP-based global annual mean fluxes over the land surface, using input data of surface radiation, temperature data from National Aeronautics and Space Administration-Clouds and the Earth's Radiant Energy System (NASA CERES) supplemented by surface specific humidity data from the Modern-Era Retrospective Analysis for Research and Applications (MERRA), agree closely with previous estimates. The new estimate of ocean evaporation, not using the MERRA reanalysis data as model inputs, is lower than previous estimates, while the new estimate of ocean sensible heat flux is higher than previously reported. The MEP model also produces the first global map of ocean surface heat flux that is not available from existing global reanalysis products.

  11. Energy budget, behavior and leptin in striped hamsters subjected to food restriction and refeeding.

    Directory of Open Access Journals (Sweden)

    Zhi-Jun Zhao

    Full Text Available Food restriction induces a loss of body mass that is often followed by rapid regaining of the lost weight when the restriction ends, consequently increasing a risk of development of obesity. To determine the physiological and behavioral mechanisms underlining the regaining, striped hamsters were restricted to 85% of initial food intake for 4 weeks and refed ad libitum for another 4 weeks. Changes in body mass, energy budget, activity, body composition and serum leptin level were measured. Body mass, body fat mass and serum leptin level significantly decreased in food-restricted hamsters, and increased when the restriction ended, showing a short "compensatory growth" rather than over-weight or obesity compared with ad libitum controls. During restriction, the time spent on activity increased significantly, which was opposite to the changes in serum leptin level. Food intake increased shortly during refeeding, which perhaps contributed to the rapid regaining of body mass. No correlation was observed between serum leptin and energy intake, while negative correlations were found in hamsters that were refed for 7 and 28 days. Exogenous leptin significantly decreased the time spent on activity during food restriction and attenuated the increase in food intake during refeeding. This suggests that low leptin in restricted animals may function as a starvation signal to induce an increase in activity behavior, and high leptin likely serves as a satiety signal to prevent activity during refeeding. Leptin may play a crucial role in controlling food intake when the restriction ends, and consequently preventing overweight.

  12. Revisiting the global surface energy budgets with maximum-entropy-production model of surface heat fluxes

    Science.gov (United States)

    Huang, Shih-Yu; Deng, Yi; Wang, Jingfeng

    2017-09-01

    The maximum-entropy-production (MEP) model of surface heat fluxes, based on contemporary non-equilibrium thermodynamics, information theory, and atmospheric turbulence theory, is used to re-estimate the global surface heat fluxes. The MEP model predicted surface fluxes automatically balance the surface energy budgets at all time and space scales without the explicit use of near-surface temperature and moisture gradient, wind speed and surface roughness data. The new MEP-based global annual mean fluxes over the land surface, using input data of surface radiation, temperature data from National Aeronautics and Space Administration-Clouds and the Earth's Radiant Energy System (NASA CERES) supplemented by surface specific humidity data from the Modern-Era Retrospective Analysis for Research and Applications (MERRA), agree closely with previous estimates. The new estimate of ocean evaporation, not using the MERRA reanalysis data as model inputs, is lower than previous estimates, while the new estimate of ocean sensible heat flux is higher than previously reported. The MEP model also produces the first global map of ocean surface heat flux that is not available from existing global reanalysis products.

  13. Energy Budget, Behavior and Leptin in Striped Hamsters Subjected to Food Restriction and Refeeding

    Science.gov (United States)

    Zhao, Zhi-Jun; Zhu, Qiao-Xia; Chen, Ke-Xin; Wang, Yu-Kun; Cao, Jing

    2013-01-01

    Food restriction induces a loss of body mass that is often followed by rapid regaining of the lost weight when the restriction ends, consequently increasing a risk of development of obesity. To determine the physiological and behavioral mechanisms underlining the regaining, striped hamsters were restricted to 85% of initial food intake for 4 weeks and refed ad libitum for another 4 weeks. Changes in body mass, energy budget, activity, body composition and serum leptin level were measured. Body mass, body fat mass and serum leptin level significantly decreased in food-restricted hamsters, and increased when the restriction ended, showing a short “compensatory growth” rather than over-weight or obesity compared with ad libitum controls. During restriction, the time spent on activity increased significantly, which was opposite to the changes in serum leptin level. Food intake increased shortly during refeeding, which perhaps contributed to the rapid regaining of body mass. No correlation was observed between serum leptin and energy intake, while negative correlations were found in hamsters that were refed for 7 and 28 days. Exogenous leptin significantly decreased the time spent on activity during food restriction and attenuated the increase in food intake during refeeding. This suggests that low leptin in restricted animals may function as a starvation signal to induce an increase in activity behavior, and high leptin likely serves as a satiety signal to prevent activity during refeeding. Leptin may play a crucial role in controlling food intake when the restriction ends, and consequently preventing overweight. PMID:23372694

  14. Closing the Energy Budget: Advances in assessing heat fluxes into shallow lakes and ponds (Invited)

    Science.gov (United States)

    Tyler, S. W.; Hausner, M. B.; Suarez, F. I.; Selker, J. S.

    2009-12-01

    While soil heat flux is traditionally directly measured in any land surface energy study, measuring heat flux into and out of lakes and ponds is complicated by water column mixing processes, differing radiation adsorption coefficients, turbidity variation and heat flux through the sediment-water interface. High resolution thermal profile, to assess heat storage changes in aquatic systems is both time consuming and challenging using traditional thermister or thermocouple strings or casts. Recent advances in Raman spectra distributed temperature sensing (DTS) offer the opportunity to measure, at high spatial and temporal resolution, the thermal storage changes occurring in lakes and ponds. Measurements of thermal storage using DTS are presented from two distinct environments; a strongly density stratified solar pond and a deep cavern system (Devils Hole in Death Valley National Park), demonstrating the effectiveness of high resolution temperature measurements. In the solar pond environment, closure of the energy budget using direct measurements of evaporation and net radiation was greatly improved by incorporating transient thermal measurements, and the development of a cooling boundary layer easily shown. At Devils Hole, variations in shading of the water surface produced small but measureable horizontal gradients in water column temperature for short periods of the day, which impact both pool evaporation and the metabolism and behavior of aquatic organisms

  15. Sediment and nutrient budgets are inherently dynamic: evidence from a long-term study of two subtropical reservoirs

    Science.gov (United States)

    O'Brien, Katherine R.; Weber, Tony R.; Leigh, Catherine; Burford, Michele A.

    2016-12-01

    Accurate reservoir budgets are important for understanding regional fluxes of sediment and nutrients. Here we present a comprehensive budget of sediment (based on total suspended solids, TSS), total nitrogen (TN) and total phosphorus (TP) for two subtropical reservoirs on rivers with highly intermittent flow regimes. The budget is completed from July 1997 to June 2011 on the Somerset and Wivenhoe reservoirs in southeast Queensland, Australia, using a combination of monitoring data and catchment model predictions. A major flood in January 2011 accounted for more than half of the water entering and leaving both reservoirs in that year, and approximately 30 % of water delivered to and released from Wivenhoe over the 14-year study period. The flood accounted for an even larger proportion of total TSS and nutrient loads: in Wivenhoe more than one-third of TSS inputs and two-thirds of TSS outputs between 1997 and 2011 occurred during January 2011. During non-flood years, mean historical concentrations provided reasonable estimates of TSS and nutrient loads leaving the reservoirs. Calculating loads from historical mean TSS and TP concentrations during January 2011, however, would have substantially underestimated outputs over the entire study period, by up to a factor of 10. The results have important implications for sediment and nutrient budgets in catchments with highly episodic flow. First, quantifying inputs and outputs during major floods is essential for producing reliable long-term budgets. Second, sediment and nutrient budgets are dynamic, not static. Characterizing uncertainty and variability is therefore just as important for meaningful reservoir budgets as accurate quantification of loads.

  16. The Flare Irradiance Spectral Model (FISM) and its Contributions to Space Weather Research, the Flare Energy Budget, and Instrument Design

    Science.gov (United States)

    Chamberlin, Phillip

    2008-01-01

    The Flare Irradiance Spectral Model (FISM) is an empirical model of the solar irradiance spectrum from 0.1 to 190 nm at 1 nm spectral resolution and on a 1-minute time cadence. The goal of FISM is to provide accurate solar spectral irradiances over the vacuum ultraviolet (VUV: 0-200 nm) range as input for ionospheric and thermospheric models. The seminar will begin with a brief overview of the FISM model, and also how the Solar Dynamics Observatory (SDO) EUV Variability Experiment (EVE) will contribute to improving FISM. Some current studies will then be presented that use FISM estimations of the solar VUV irradiance to quantify the contributions of the increased irradiance from flares to Earth's increased thermospheric and ionospheric densites. Initial results will also be presented from a study looking at the electron density increases in the Martian atmosphere during a solar flare. Results will also be shown quantifying the VUV contributions to the total flare energy budget for both the impulsive and gradual phases of solar flares. Lastly, an example of how FISM can be used to simplify the design of future solar VUV irradiance instruments will be discussed, using the future NOAA GOES-R Extreme Ultraviolet and X-Ray Sensors (EXIS) space weather instrument.

  17. Large wood budget and transport dynamics on a large river using radio telemetry

    Science.gov (United States)

    Schenk, Edward R.; Moulin, Bertrand; Hupp, Cliff R.; Richte, Jean M.

    2014-01-01

    Despite the abundance of large wood (LW) river studies there is still a lack of understanding of LW transport dynamics on large low gradient rivers. This study used 290 radio frequency identification tagged (RFID) LW and 54 metal (aluminum) tagged LW, to quantify the percent of in-channel LW that moves per year and what variables play a role in LW transport dynamics. Aluminum tags were installed and monitored on LW in-transit during the rising limb of a flood, the mean distance traveled by those pieces during the week was 13.3 river kilometers (km) with a maximum distance of 72 km. RFID tagged LW moved a mean of 11.9 km/yr with a maximum observed at 101.1 km/yr. Approximately 41% of LW low on the bank moves per year. The high rate of transport and distance traveled is likely due to the lack of interaction between LW floating in the channel and the channel boundaries, caused primarily by the width of the channel relative to length of the LW. Approximately 80% of the RFID tags moved past a fixed reader during the highest 20% of river stage per year. LW transport and logjam dynamics are complicated at high flows as pieces form temporary jams that continually expand and contract. Unlike most other studies, key members that create a logjam were defined more by stability than jam size or channel/hydrologic conditions. Finally, using an existing geomorphic database for the river, and data from this study, we were able to develop a comprehensive LW budget showing that 5% of the in-channel LW population turns over each year (input from mass wasting and fluvial erosion equals burial, decomposition, and export out of system) and another 16% of the population moving within the system.

  18. KMOS3D: Dynamical Constraints on the Mass Budget in Early Star-forming Disks

    Science.gov (United States)

    Wuyts, Stijn; Förster Schreiber, Natascha M.; Wisnioski, Emily; Genzel, Reinhard; Burkert, Andreas; Bandara, Kaushala; Beifiori, Alessandra; Belli, Sirio; Bender, Ralf; Brammer, Gabriel B.; Chan, Jeffrey; Davies, Ric; Fossati, Matteo; Galametz, Audrey; Kulkarni, Sandesh K.; Lang, Philipp; Lutz, Dieter; Mendel, J. Trevor; Momcheva, Ivelina G.; Naab, Thorsten; Nelson, Erica J.; Saglia, Roberto P.; Seitz, Stella; Tacconi, Linda J.; Tadaki, Ken-ichi; Übler, Hannah; van Dokkum, Pieter G.; Wilman, David J.; Wuyts, Eva

    2016-11-01

    We exploit deep integral-field spectroscopic observations with KMOS/Very Large Telescope of 240 star-forming disks at 0.6\\lt z\\lt 2.6 to dynamically constrain their mass budget. Our sample consists of massive (≳ {10}9.8 {M}⊙ ) galaxies with sizes {R}e≳ 2 {kpc}. By contrasting the observed velocity and dispersion profiles with dynamical models, we find that on average the stellar content contributes {32}-7+8 % of the total dynamical mass, with a significant spread among galaxies (68th percentile range {f}{star}˜ 18 % {--}62 % ). Including molecular gas as inferred from CO- and dust-based scaling relations, the estimated baryonic mass adds up to {56}-12+17 % of the total for the typical galaxy in our sample, reaching ˜ 90 % at z\\gt 2. We conclude that baryons make up most of the mass within the disk regions of high-redshift star-forming disk galaxies, with typical disks at z\\gt 2 being strongly baryon-dominated within R e . Substantial object-to-object variations in both stellar and baryonic mass fractions are observed among the galaxies in our sample, larger than what can be accounted for by the formal uncertainties in their respective measurements. In both cases, the mass fractions correlate most strongly with measures of surface density. High-{{{Σ }}}{star} galaxies feature stellar mass fractions closer to unity, and systems with high inferred gas or baryonic surface densities leave less room for additional mass components other than stars and molecular gas. Our findings can be interpreted as more extended disks probing further (and more compact disks probing less far) into the dark matter halos that host them. Based on observations collected at the European Organisation for Astronomical Research in the Southern Hemisphere under ESO programs 092.A-0091, 093.A-0079, 094.A-0217, 095.A-0047, and 096.A-0025.

  19. Energy exchange analysis in droplet dynamics via the Navier–Stokes–Cahn–Hilliard model

    KAUST Repository

    Espath, L. F. R.

    2016-05-23

    We develop the energy budget equation of the coupled Navier-Stokes-Cahn-Hilliard (NSCH) system. We use the NSCH equations to model the dynamics of liquid droplets in a liquid continuum. Buoyancy effects are accounted for through the Boussinesq assumption. We physically interpret each quantity involved in the energy exchange to gain further insight into the model. Highly resolved simulations involving density-driven flows and the merging of droplets allow us to analyse these energy budgets. In particular, we focus on the energy exchanges when droplets merge, and describe flow features relevant to this phenomenon. By comparing our numerical simulations to analytical predictions and experimental results available in the literature, we conclude that modelling droplet dynamics within the framework of NSCH equations is a sensible approach worthy of further research. © 2016 Cambridge University Press.

  20. BEYOND BUDGETING

    Directory of Open Access Journals (Sweden)

    Edo Cvrkalj

    2015-12-01

    Full Text Available Traditional budgeting principles, with strictly defined business goals, have been, since 1998, slowly growing into more sophisticated and organization-adjusted alternative budgeting concepts. One of those alternative concepts is the “Beyond budgeting” model with an implemented performance effects measuring process. In order for the model to be practicable, budget planning and control has to be reoriented to the “bottom up” planning and control approach. In today’s modern business surroundings one has to take both present and future opportunities and threats into consideration, by valorizing them in a budget which would allow a company to realize a whole pallet of advantages over the traditional budgeting principles which are presented later in the article. It is essential to emphasize the importance of successfully implementing the new budgeting principles within an organization. If the implementation has been lacking and done without a higher goal in mind, it is easily possible that the process has been implemented without coordination, planning and control framework within the organization itself. Further in the article we present an overview of managerial techniques and instruments within the “Beyond budgeting” model such as balanced scorecard, rolling forecast, dashboard, KPI and other supporting instruments. Lastly we define seven steps for implementing the “Beyond budgeting” model and offer a comparison of “Beyond budgeting” model against traditional budgeting principles which lists twelve reasons why “Beyond budgeting” is better suited to modern and market-oriented organizations. Each company faces those challenges in their own characteristic way but implementing new dynamic planning models will soon become essential for surviving in the market.

  1. A global assessment of the local impacts of land cover changes on the surface energy budget

    Science.gov (United States)

    Cescatti, A.; Duveiller, G.; Hooker, J.

    2016-12-01

    Biophysical effects of land use and land cover change (LULCC) on climate have received less attention than biogeochemical effects. Yet, their impact is potentially more perceptible because the effect is almost immediate at local scales. Biophysical effects depend on the specific LULCC transition, and can change in sign and magnitude across space and time. Spatially explicit assessments are therefore required to describe these phenomena. Whilst accurately characterising these local biophysical effects using Land Surface Models (LSMs) can be problematic given the strong modelling assumptions that must be made, satellite remote sensing instruments operationally measure several of the key energy fluxes at high temporal and spatial resolution across the entire planet. We leverage this synoptic property of remote sensing to develop a methodology capable of isolating the biophysical signal of potential vegetation transitions at local scale. Because mapping LULCC accurately at global scale is notoriously challenging, and because many potential transitions may not yet have occurred in various places, the approach relies on trading space for time over a moving window as a surrogate for monitoring real change. The result is a global dataset with a spatial resolution of 1° indicating the potential change in all terms of the surface energy balance (excepting the soil heat flux) for all transitions amongst 7 different plant functional types that are widely used by the land surface modelling community. This dataset will serve three main purposes: (1) to derive a data-driven diagnostic of the local biophysical effects of LULCC on the surface energy budget and local climate; (2) to provide a benchmark to assess model performances; and (3) to develop guidelines for the monitoring, reporting and verification of climate mitigation and adaptation plans that account for land biophysical impacts on climate.

  2. Revisiting the Earth's sea-level and energy budgets from 1961 to 2008

    Science.gov (United States)

    Church, John A.; White, Neil J.; Konikow, Leonard F.; Domingues, Catia M.; Cogley, J. Graham; Rignot, Eric; Gregory, Jonathan M.; van den Broeke, Michiel R.; Monaghan, Andrew J.; Velicogna, Isabella

    2011-01-01

    We review the sea-level and energy budgets together from 1961, using recent and updated estimates of all terms. From 1972 to 2008, the observed sea-level rise (1.8 0.2 mm yr-1 from tide gauges alone and 2.1 0.2 mm yr -1 from a combination of tide gauges and altimeter observations) agrees well with the sum of contributions (1.8 0.4 mm yr-1) in magnitude and with both having similar increases in the rate of rise during the period. The largest contributions come from ocean thermal expansion (0.8 mm yr-1) and the melting of glaciers and ice caps (0.7 mm yr -1), with Greenland and Antarctica contributing about 0.4 mm yr -1. The cryospheric contributions increase through the period (particularly in the 1990s) but the thermosteric contribution increases less rapidly. We include an improved estimate of aquifer depletion (0.3 mm yr -1), partially offsetting the retention of water in dams and giving a total terrestrial storage contribution of-0.1 mm yr-1. Ocean warming (90% of the total of the Earth's energy increase) continues through to the end of the record, in agreement with continued greenhouse gas forcing. The aerosol forcing, inferred as a residual in the atmospheric energy balance, is estimated as-0.8 0.4 W m-2 for the 1980s and early 1990s. It increases in the late 1990s, as is required for consistency with little surface warming over the last decade. This increase is likely at least partially related to substantial increases in aerosol emissions from developing nations and moderate volcanic activity. Copyright 2011 by the American Geophysical Union.

  3. A Dynamic Model for Energy Structure Analysis

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    Energy structure is a complicated system concerning economic development, natural resources, technological innovation, ecological balance, social progress and many other elements. It is not easy to explain clearly the developmental mechanism of an energy system and the mutual relations between the energy system and its related environments by the traditional methods. It is necessary to develop a suitable dynamic model, which can reflect the dynamic characteristics and the mutual relations of the energy system and its related environments. In this paper, the historical development of China's energy structure was analyzed. A new quantitative analysis model was developed based on system dynamics principles through analysis of energy resources, and the production and consumption of energy in China and comparison with the world. Finally, this model was used to predict China's future energy structures under different conditions.

  4. Carbon budget estimation of a subarctic catchment using a dynamic ecosystem model at high spatial resolution

    Directory of Open Access Journals (Sweden)

    J. Tang

    2015-01-01

    Eriophorum, Sphagnum and then tundra heath during the observation periods. The catchment-level carbon fluxes from aquatic systems are dominated by CO2 emissions from streams. Integrated across the whole catchment, we estimate that the area is a carbon sink at present, and will become an even stronger carbon sink by 2080, which is mainly a result of a projected densification of birch forest and its encroachment into tundra heath. However, the magnitudes of the modelled sinks are very dependent on future atmospheric CO2 concentrations. Furthermore, comparisons of global warming potentials between two simulations with and without CO2 increase since 1960 reveal that the increased methane emission from the peatland could double the warming effects of the whole catchment by 2080 in the absence of CO2 fertilization of the vegetation. This is the first process-based model study of the temporal evolution of a catchment-level carbon budget at high spatial resolution, integrating comprehensive and diverse fluxes including both terrestrial and aquatic carbon. Though this study also highlights some limitations in modelling subarctic ecosystem responses to climate change including aquatic system flux dynamics, nutrient limitation, herbivory and other disturbances and peatland expansion, our application provides a mechanism to resolve the complexity of carbon cycling in subarctic ecosystems while simultaneously pointing out the key model developments for capturing complex subarctic processes.

  5. Cost Control Strategies for Zero Energy Buildings: High-Performance Design and Construction on a Budget (Brochure)

    Energy Technology Data Exchange (ETDEWEB)

    2014-09-01

    There is mounting evidence that zero energy can, in many cases, be achieved within typical construction budgets. To ensure that the momentum behind zero energy buildings and other low-energy buildings will continue to grow, this guide assembles recommendations for replicating specific successes of early adopters who have met their energy goals while controlling costs. Contents include: discussion of recommended cost control strategies, which are grouped by project phase (acquisition and delivery, design, and construction) and accompanied by industry examples; recommendations for balancing key decision-making factors; and quick reference tables that can help teams apply strategies to specific projects.

  6. Survey of Recipients of WAP Services Assessment of Household Budget and Energy Behaviors Pre to Post Weatherization DOE

    Energy Technology Data Exchange (ETDEWEB)

    Tonn, Bruce Edward [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Rose, Erin M. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Hawkins, Beth A. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)

    2015-10-01

    This report presents results from the national survey of weatherization recipients. This research was one component of the retrospective and Recovery Act evaluations of the U.S. Department of Energy s Weatherization Assistance Program. Survey respondents were randomly selected from a nationally representative sample of weatherization recipients. The respondents and a comparison group were surveyed just prior to receiving their energy audits and then again approximately 18 months post-weatherization. This report focuses on budget issues faced by WAP households pre- and post-weatherization, whether household energy behaviors changed from pre- to post, the effectiveness of approaches to client energy education, and use and knowledge about thermostats.

  7. Evidence for Solar Cycle Influence on the Infrared Energy Budget and Radiative Cooling of the Thermosphere

    Science.gov (United States)

    Mlynczak, Martin G.; Martin-Torres, F. Javier; Marshall, B. Thomas; Thompson, R. Earl; Williams, Joshua; Turpin, TImothy; Kratz, D. P.; Russell, James M.; Woods, Tom; Gordley, Larry L.

    2007-01-01

    We present direct observational evidence for solar cycle influence on the infrared energy budget and radiative cooling of the thermosphere. By analyzing nearly five years of data from the Sounding of the Atmosphere using Broadband Emission Radiometry (SABER) instrument, we show that the annual mean infrared power radiated by the nitric oxide (NO) molecule at 5.3 m has decreased by a factor of 2.9. This decrease is correlated (r = 0.96) with the decrease in the annual mean F10.7 solar index. Despite the sharp decrease in radiated power (which is equivalent to a decrease in the vertical integrated radiative cooling rate), the variability of the power as given in the standard deviation of the annual means remains approximately constant. A simple relationship is shown to exist between the infrared power radiated by NO and the F10.7 index, thus providing a fundamental relationship between solar activity and the thermospheric cooling rate for use in thermospheric models. The change in NO radiated power is also consistent with changes in absorbed ultraviolet radiation over the same time period.

  8. Borehole temperatures reveal a changed energy budget at Mill Island, East Antarctica over recent decades

    Directory of Open Access Journals (Sweden)

    J. L. Roberts

    2012-07-01

    Full Text Available A borehole temperature record from the Mill Island (East Antarctic icecap reveals a large surface warming signal manifested as a 0.75 K temperature difference over the approximate 100 m depth below the seasonally varying zone. The temperature profile shows a break in gradient between 49 and 69 m depth, which we model with inverse numerical simulations, indicating that surface warming started around the austral summer of 1980/1981 AD ± 5 yr. This warming of approximately 0.37 K per decade is large by Antarctic standards and is only exceeded in regions of the Antarctic Peninsula. While this warming may reflect regional scale air temperature increases, the lack of comparable trends for other East Antarctic sites suggests local influences are largely responsible for the observed trend. Alteration of the surface energy budget arising from changes in radiation balances due to local cloud, the amount of liquid deposition and local air temperatures associated with altered air/sea exchanges potentially play a key role at this location due to the proximity of the Shackleton Ice Shelf and sea-ice zone.

  9. Borehole temperatures reveal a changed energy budget at Mill Island, East Antarctica, over recent decades

    Directory of Open Access Journals (Sweden)

    J. L. Roberts

    2013-02-01

    Full Text Available A borehole temperature record from the Mill Island (East Antarctica icecap reveals a large surface warming signal manifested as a 0.75 K temperature difference over the approximate 100 m depth in the zone of zero annual amplitude below the seasonally varying zone. The temperature profile shows a break in gradient around 49 m depth, which we model with inverse numerical simulations, indicating that surface warming started around the austral summer of 1980/81 AD ±5 yr. This warming of approximately 0.37 K per decade is consistent with trends seen in both instrumental and other reconstructions for Antarctica and, therefore, suggests that regional- rather than local-scale processes are largely responsible. Alteration of the surface energy budget arising from changes in radiation balances due to local cloud, the amount of liquid deposition and local air temperatures associated with altered air/sea exchanges also potentially plays a role at this location due to the proximity of the Shackleton Ice Shelf and sea-ice zone.

  10. Carbon budget estimation of a subarctic catchment using a dynamic ecosystem model at high spatial resolution

    Science.gov (United States)

    Tang, J.; Miller, P. A.; Persson, A.; Olefeldt, D.; Pilesjo, P.; Heliasz, M.; Jackowicz-Korczynski, M.; Yang, Z.; Smith, B.; Callaghan, T. V.; Christensen, T. R.

    2015-05-01

    A large amount of organic carbon is stored in high-latitude soils. A substantial proportion of this carbon stock is vulnerable and may decompose rapidly due to temperature increases that are already greater than the global average. It is therefore crucial to quantify and understand carbon exchange between the atmosphere and subarctic/arctic ecosystems. In this paper, we combine an Arctic-enabled version of the process-based dynamic ecosystem model, LPJ-GUESS (version LPJG-WHyMe-TFM) with comprehensive observations of terrestrial and aquatic carbon fluxes to simulate long-term carbon exchange in a subarctic catchment at 50 m resolution. Integrating the observed carbon fluxes from aquatic systems with the modeled terrestrial carbon fluxes across the whole catchment, we estimate that the area is a carbon sink at present and will become an even stronger carbon sink by 2080, which is mainly a result of a projected densification of birch forest and its encroachment into tundra heath. However, the magnitudes of the modeled sinks are very dependent on future atmospheric CO2 concentrations. Furthermore, comparisons of global warming potentials between two simulations with and without CO2 increase since 1960 reveal that the increased methane emission from the peatland could double the warming effects of the whole catchment by 2080 in the absence of CO2 fertilization of the vegetation. This is the first process-based model study of the temporal evolution of a catchment-level carbon budget at high spatial resolution, including both terrestrial and aquatic carbon. Though this study also highlights some limitations in modeling subarctic ecosystem responses to climate change, such as aquatic system flux dynamics, nutrient limitation, herbivory and other disturbances, and peatland expansion, our study provides one process-based approach to resolve the complexity of carbon cycling in subarctic ecosystems while simultaneously pointing out the key model developments for capturing

  11. Climate change driven water budget dynamics of a Tibetan inland lake

    Science.gov (United States)

    Li, Binquan; Zhang, Jianyun; Yu, Zhongbo; Liang, Zhongmin; Chen, Li; Acharya, Kumud

    2017-03-01

    Understanding the hydrologic processes of inland lake basins in the Tibetan Plateau (TP) could provide insights into the responses of Tibetan lake dynamics to climate change. An efficient approach for this purpose is to represent complex hydrologic behaviors of such Tibetan lake watersheds with plausible hydrologic models. In this study, water level fluctuations of Lake Nam Co, an inland lake in the central TP, were investigated using a lumped lake-watershed model. The degree-day factor method was introduced to improve the model applicability in glacier-covered basins. The model simulated the hydrologic processes as well as the lake water budget. Remote sensing images (Landsat MSS, TM, ETM + and OLI) from 1972 to 2015 were used to identify the glacier and lake boundaries. Multisource climate data (e.g., ground point observation, 0.25o gridded APHRODITE and TRMM 3B42 v7 precipitation products) were used to drive the hydrologic model at a monthly time step. Results of trend analysis showed that basin-wide annual air temperature increased by the rate 0.04 °C/yr from 1961 to 2015. Mean annual precipitation slowly increased from 1961 to the mid-1990s, and then rapidly increased from the late-1990s to the mid-2000s, and finally obviously decreased after the mid-2000s. As a response to climate change, glaciers decreased by 62.69 km2 (29%) and lake area increased by 91.83 km2 (4.7%) from 1972 to 2015. The analysis of lake water budget suggested that, the total basin runoff and on-lake precipitation contributed 1.36 km3/yr (66%) and 0.7 km3/yr (34%), respectively, to mean annual water gain of the lake. Glacier runoff was 14% of the basin runoff and 10% of the total water gain of the lake. The percentages of lake evaporation, water seepage and water surplus were 65%, 20% and 15%, respectively. Lake level increased with the rate of 0.14 m/yr for the study period 1961-2015. It could be concluded that precipitation was the dominant controlling factor for the different

  12. Simulation of arctic surface radiation and energy budget during the summertime using the single-column model

    Institute of Scientific and Technical Information of China (English)

    LI Xiang; WANG Hui; ZHANG Zhanhai; WU Huiding

    2008-01-01

    The surface heat budget of the Arctic Ocean (SHEBA) project has shown that the study of the surface heat budget characteristics is crucial to understanding the interface process and environmental change in the polar region.An arctic single-column model (ARCSCM) of Colorado University is used to simulate the arctic surface radiation and energy budget during the summertime.The simulation results are analyzed and compared with the SHEBA measurements.Sensitivity analyses are performed to test microphys- ical and radiative parameterizations in this model.The results show that the ARCSCM model is able to simulate the surface radia- tion and energy budget in the arctic during the summertime,and the different parameterizations have a significant influence on the results.The combination of cloud microphysics and RRTM parameterizations can fairly derive the surface solar shortwave radiation and downwelling Iongwave radiation flux.But this cloud microphysics parameterization scheme deviates notably from the simula- tion of surface sensible and latent heat flux.Further improvement for the parameterization scheme applied to the Arctic Regions is necessary.

  13. The 20th Century evolution of energy budgets and meridional transports in two AMIP-like experiments

    Science.gov (United States)

    Lembo, Valerio; Folini, Doris; Wild, Martin; Lionello, Piero

    2016-04-01

    The 20th century evolution and spatial patterns of the Top-of-Atmosphere (TOA), atmospheric, and surface energy budgets (EB) are investigated in this work. These are computed as the balance between the radiative and heat fluxes at the TOA and at the surface. Total, atmospheric and oceanic meridional energy transports are computed from the EBs. Two AMIP-like ensemble simulations are considered: Integrated Forecast System (IFS) simulations of the ERA-20CM experiment, and ECHAM5-HAM model simulations. With the latter, additional sensitivity experiments are carried out by constraining either Sea-Surface Temperatures (SST) and Sea-Ice Cover (SIC) or aerosol concentrations to climatological values. The recent decades estimates of the EB are in reasonable agreement in the two models, while they are not for what concerns the global scale evolution. Particularly, in the 1970s ERA-20CM shows a fast transition from negative to positive EBs at Top of Atmosphere (TOA) that is not found in ECHAM5-HAM. The impact of aerosols, as evidenced by the sensitivity experiments with ECHAM5-HAM, is seen to set up an inter-hemispheric gradient in the TOA and surface budget after 1960. This is also reflected by an increased total poleward transport in the Northern Hemisphere and decreased in the Southern Hemisphere. This feature is not found in ERA-20CM. SST variations do not seem to induce long-term variations in the patterns of TOA budget and related total meridional transport. Nevertheless most of the surface and atmospheric budget and transport inter-annual variability is attributable to the evolution of SST, and much more agreement is observed among the two models in this respect. Reference: Lembo V, Doris F, Martin W, and Lionello P (2015) Energy budgets and transports: global evolution and spatial patterns during the 20th Century as estimated in two AMIP-like experiments, Clim. Dyn., subm.

  14. Seasonal and diurnal variation of energy budget components in coniferous forests

    Science.gov (United States)

    Lindroth, Anders

    1985-11-01

    This study was part of the large multidisciplinary ecosystem investigations undertaken in Sweden during the 70's. One of the main aims of the abiotic research was to deepen our understanding of the physical processes governing the local- and microclimate of northern coniferous forests. As part of this, the energy budget of a sparse pine forest in central Sweden was intensively studied. Analysis of Bowen ratio measurements during 1977 and 1978 showed that the fraction of net radiation ( Rn) utilized for sensible and latent heat ( LE) fluxes was not constant over the season. The ratio {LE}/{R n} increased from about 40% in May to about 60% in August and September. The mean daytime latent heat flux from a dry canopy was about 135 W m -2 in May, increasing to 150-160 W m -2 in July and August and then decreasing to 100 W m -2 in September. The sensible heat flux decreased from about 190 W m -2 in May to 55 W m -2 in September. The mean daytime energy storage rate was largest in May and September with about 23 W m -2 and smallest in July with 12 W m -2. The Bowen ratio at noon decreased from about 2 in May to 0.5-1 in August and September. During a period of six days, simultaneous measurements of evapotranspiration from the ground vegetation and the whole forest were made. Averaged over the daytime period, about 59% of the net radiation was used for latent heat flux, 32% for sensible heat flux and 9% for storage. Only 13% of the latent heat flux came from the ground vegetation while more than 50% of the sensible heat flux originated from the ground. Comparison between four European coniferous forests showed that the mean daytime latent heat flux varied relatively little. The mean rate was 135 ± 27 W m -2 and there was no correlation between density of forest and rate of latent heat flux.

  15. Climatic effects of 30 years of landscape change over the Greater Phoenix, Arizona, region: 1. Surface energy budget changes

    Science.gov (United States)

    Georgescu, M.; Miguez-Macho, G.; Steyaert, L.T.; Weaver, C.P.

    2009-01-01

    This paper is part 1 of a two-part study that evaluates the climatic effects of recent landscape change for one of the nation's most rapidly expanding metropolitan complexes, the Greater Phoenix, Arizona, region. The region's landscape evolution over an approximate 30-year period since the early 1970s is documented on the basis of analyses of Landsat images and land use/land cover (LULC) data sets derived from aerial photography (1973) and Landsat (1992 and 2001). High-resolution, Regional Atmospheric Modeling System (RAMS), simulations (2-km grid spacing) are used in conjunction with consistently defined land cover data sets and associated biophysical parameters for the circa 1973, circa 1992, and circa 2001 time periods to quantify the impacts of intensive land use changes on the July surface temperatures and the surface radiation and energy budgets for the Greater Phoenix region. The main findings are as follows: since the early 1970s the region's landscape has been altered by a significant increase in urban/suburban land area, primarily at the expense of decreasing plots of irrigated agriculture and secondarily by the conversion of seminatural shrubland. Mean regional temperatures for the circa 2001 landscape were 0.12??C warmer than the circa 1973 landscape, with maximum temperature differences, located over regions of greatest urbanization, in excess of 1??C. The significant reduction in irrigated agriculture, for the circa 2001 relative to the circa 1973 landscape, resulted in dew point temperature decreases in excess of 1??C. The effect of distinct land use conversion themes (e.g., conversion from irrigated agriculture to urban land) was also examined to evaluate how the most important conversion themes have each contributed to the region's changing climate. The two urbanization themes studied (from an initial landscape of irrigated agriculture and seminatural shrubland) have the greatest positive effect on near-surface temperature, increasing maximum daily

  16. The impact of the global budget system on dynamics of dental manpower and utilization of dental services

    Directory of Open Access Journals (Sweden)

    Laura Yueh-Guey Huang

    2016-01-01

    Conclusion: This study has demonstrated a stabilizing effect of the global budget system on dynamics of dental manpower in Taiwan. A relationship between HHI and dentists′ move-out rate has been found. The relationship between municipal socioeconomic status and the density of dentists has also been confirmed. In addition, reduced utilization of amalgam restorations was accompanied by increased utilization of tooth-colored material restorations. Further investigations are indicated.

  17. New approaches for household energy conservation - In search of personal household energy budgets and energy reduction options

    NARCIS (Netherlands)

    Benders, René M.J.; Kok, Rixt; Moll, Henri C.; Wiersma, Gerwin; Noorman, Klaas Jan

    2006-01-01

    Large-scale energy reduction campaigns focusing on households generally have two shortcomings. First, an energy reduction campaign is either personalized but time intensive or time extensive but generalized. Second, because only the direct energy requirements are addressed, only 50% of the total hou

  18. Ecological Energetics of the Kestrel : Daily Energy Expenditure throughout the Year Based on Time-Energy Budget, Food Intake and Doubly Labeled Water Methods

    NARCIS (Netherlands)

    Masman, Dirkjan; Daan, Serge; Beldhuis, Hans J.A.

    1988-01-01

    1. Three methods were employed to determine the daily energy expenditure (DEE) of free-living Kestrels, throughout the year in a study area in the northern Netherlands. - TEB (time budget analysis) - Food intake (observational method) - DLW (doubly labeled water method) 2. The TEB model used here re

  19. Scaling of brain metabolism with a fixed energy budget per neuron: implications for neuronal activity, plasticity and evolution.

    Science.gov (United States)

    Herculano-Houzel, Suzana

    2011-03-01

    It is usually considered that larger brains have larger neurons, which consume more energy individually, and are therefore accompanied by a larger number of glial cells per neuron. These notions, however, have never been tested. Based on glucose and oxygen metabolic rates in awake animals and their recently determined numbers of neurons, here I show that, contrary to the expected, the estimated glucose use per neuron is remarkably constant, varying only by 40% across the six species of rodents and primates (including humans). The estimated average glucose use per neuron does not correlate with neuronal density in any structure. This suggests that the energy budget of the whole brain per neuron is fixed across species and brain sizes, such that total glucose use by the brain as a whole, by the cerebral cortex and also by the cerebellum alone are linear functions of the number of neurons in the structures across the species (although the average glucose consumption per neuron is at least 10× higher in the cerebral cortex than in the cerebellum). These results indicate that the apparently remarkable use in humans of 20% of the whole body energy budget by a brain that represents only 2% of body mass is explained simply by its large number of neurons. Because synaptic activity is considered the major determinant of metabolic cost, a conserved energy budget per neuron has several profound implications for synaptic homeostasis and the regulation of firing rates, synaptic plasticity, brain imaging, pathologies, and for brain scaling in evolution.

  20. Evaluation of the Modern Era Retrospective-Analysis for Research and Applications (MERRA) Global Water and Energy Budgets

    Science.gov (United States)

    Bosilovich, Michael G.; Robertson, F. R.; Chen, J.

    2010-01-01

    The Modern Era Retrospective-analysis for Research and Applications (MERRA) reanalyses has completed 27 years of data) soon to be caught up to present. Here) we present an evaluation of those years currently available) including comparisons with the existing long reanalyses (ERA40) JRA25 and NCEP I and II) as well as with global data sets for the water and energy cycle. Time series shows that the MERRA budgets can change with some of the variations in observing systems, but that the magnitude of energy imbalance in the system is improved with more observations. We will present all terms of the budgets in MERRA including the time rates of change and analysis increments (tendency due to the analysis of observations).

  1. A transitioning Arctic surface energy budget: the impacts of solar zenith angle, surface albedo and cloud radiative forcing

    Energy Technology Data Exchange (ETDEWEB)

    Sedlar, Joseph; Tjernstroem, Michael; Leck, Caroline [Stockholm University, Department of Meteorology, Stockholm (Sweden); Mauritsen, Thorsten [Max-Planck-Institute for Meteorology, Hamburg (Germany); Shupe, Matthew D.; Persson, P.O.G. [University of Colorado, NOAA-ESRL-PSD, Boulder, CO (United States); Brooks, Ian M.; Birch, Cathryn E. [University of Leeds, School of Earth and Environment, Leeds (United Kingdom); Sirevaag, Anders [University of Bergen, Bjerknes Center for Climate Research, Bergen (Norway); Nicolaus, Marcel [Norwegian Polar Institute, Tromsoe (Norway); Alfred Wegener Institute for Polar and Marine Research, Bremerhaven (Germany)

    2011-10-15

    Snow surface and sea-ice energy budgets were measured near 87.5 N during the Arctic Summer Cloud Ocean Study (ASCOS), from August to early September 2008. Surface temperature indicated four distinct temperature regimes, characterized by varying cloud, thermodynamic and solar properties. An initial warm, melt-season regime was interrupted by a 3-day cold regime where temperatures dropped from near zero to -7 C. Subsequently mean energy budget residuals remained small and near zero for 1 week until once again temperatures dropped rapidly and the energy budget residuals became negative. Energy budget transitions were dominated by the net radiative fluxes, largely controlled by the cloudiness. Variable heat, moisture and cloud distributions were associated with changing air-masses. Surface cloud radiative forcing, the net radiative effect of clouds on the surface relative to clear skies, is estimated. Shortwave cloud forcing ranged between -50 W m{sup -2} and zero and varied significantly with surface albedo, solar zenith angle and cloud liquid water. Longwave cloud forcing was larger and generally ranged between 65 and 85 W m{sup -2}, except when the cloud fraction was tenuous or contained little liquid water; thus the net effect of the clouds was to warm the surface. Both cold periods occurred under tenuous, or altogether absent, low-level clouds containing little liquid water, effectively reducing the cloud greenhouse effect. Freeze-up progression was enhanced by a combination of increasing solar zenith angles and surface albedo, while inhibited by a large, positive surface cloud forcing until a new air-mass with considerably less cloudiness advected over the experiment area. (orig.)

  2. Air Quality, Energy Budget, and Offset Policy in South Africa's Low-Income Settlements

    Science.gov (United States)

    Hersey, S. P.; Piketh, S.; Burger, R.

    2014-12-01

    Urban and exurban residential populations in South Africa reside primarily in low-income settlements, including many townships remaining from Apartheid. Over 3 million free government homes have been built in the last 20 years, but the number of people living in informal settlements is the same as at the end of Apartheid in 1994 - a consequence of rapid urbanization. Despite availability of electricity to the vast majority of South Africans, ~80% of electrified homes in low-income areas also burn coal and/or wood as supplementary fuels for cooking and heating. These domestic burning activities represent 70-85% of total PM10mass during winter in South Africa's low-income settlements. Here we analyze data from observations of human-atmosphere systems in: 1) 19 ground monitoring sites in Gauteng Province (Johannesburg and Pretoria), and 2) an intensive sampling campaign in a township in Mpumalanga Province (Industrial Highveld). From ground monitoring, we quantitatively describe seasonal and diurnal trends in PM10 and PM2.5 typical in low-income settlements as compared with industrial and developed suburban areas, and demonstrate the impact of low-income settlements on regional air quality. We also explore the implications of economic development in townships (increased household income, expanded commercialization and widespread electricity usage) on local and regional air quality. Data from the intensive township sampling study provides a seasonal energy budget for domestic burning in low-income settlements and suggests that indoor and ambient air quality are independent systems requiring unique interventions. We conclude with a preview of innovative strategies being developed by industry, government, and academic stakeholders for a not-like-for-like emissions offset policy in South Africa, focused on investments directly into low-income settlements that are aimed at reducing PM exposure.

  3. Impacts of Climate Variability on Surface Energy and Water Budgets in sub-Saharan Africa

    Science.gov (United States)

    Harrison, Laura Suzanne

    According to the IPCC Fifth Assessment Report, climate change will exacerbate current climate and non-climate stressors on agricultural systems in sub-Saharan Africa. This will adversely impact food security and the wellbeing of communities. Small-scale farmers grow more than 90 percent of the food produced in the region and many households depend on productive local growing conditions to support for their families. A better understanding of recent and near future climate constraints is important for identifying future food security risks and locally-appropriate adaptation strategies. This dissertation research examines impacts of weather and climate on vegetation productivity in geographically diverse areas of east Africa and the semi-arid Sahel. The focus of this research is how surface energy and water budgets respond to variations in rainfall and temperature. It asks the following questions: Where will warmer temperature pose a hazard to rainfed agriculture in the Sahel in the next 20 years? What environment and weather conditions led to above average surface temperature during the recent decade in east Africa? How have declines in rainfall since the 1980s impacted vegetation productivity and hydrology in Tanzania? The research incorporates a variety of earth observation data, including historical records from in situ, model-derived, and satellite-observed sources and projections from global climate models. A major contribution is the identification of specific areas, mainly in semi-arid climate zones, where increases in temperature and decreases to rainfall have large negative impacts on vegetation productivity. The research also presents new methods for evaluating land-atmosphere interactions in the context of hazards to vegetation.

  4. Energy budgets and a climate space diagram for the turtle, Chrysemys scripta

    Energy Technology Data Exchange (ETDEWEB)

    Foley, R. E.

    1976-01-01

    Heat energy budgets were computed and a steady state climate space was generated for a 1000 g red-eared turtle (Chrysemys scripta). Evaporative water loss (EWL) was measured from C. scripta at three wind speeds (10-400 cm sec/sup -1/) and at four air temperatures (5 to 35/sup 0/C) in a wind tunnel. EWL increased as air temperature and wind speed increased. Smaller turtles dehydrated at a faster rate than large turtles. Heat transfer by convection was measured from aluminum castings of C. scripta at three temperature differences between casting and air (..delta..T 15/sup 0/, 10/sup 0/ and 5/sup 0/C) for three windspeeds (10 to 400 cm sec/sup -1/). Convective heat transfer coefficients increased as wind speed and ..delta..T increased. Wind speed has a large effect on the shape of the climate space. At high wind speeds, heat loss by evaporation and convection are greatly increased. In still air (10 cm sec/sup -1/), a turtle cannot remain exposed to full sunlight when air temperatures exceed 19/sup 0/C. When wind speed increases to 400 cm sec/sup -1/, the turtle can bask for long periods of time at temperatures as high as 32/sup 0/C. Basking patterns of C. scripta probably shift from a unimodal pattern in the spring to a bimodal pattern in summer and return to a unimodal pattern in fall. Terrestrial activity may be extensive in the spring and fall but is limited during the hot summer months to periods of rainfall. Nesting activities cannot occur around solar noon because increased metabolic heat loading and high solar radiation intensity could cause death.

  5. Comparison of the surface energy budget between regions of seasonally frozen ground and permafrost on the Tibetan Plateau

    Science.gov (United States)

    Gu, Lianglei; Yao, Jimin; Hu, Zeyong; Zhao, Lin

    2015-02-01

    Surface energy budgets were calculated using turbulent flux observation data and meteorological gradient data collected in 2008 from two sites: BJ, located in a seasonally frozen ground region, and Tanggula, located in a permafrost region. In 2008, the energy closure ratios for the BJ and Tanggula sites were 0.74 and 0.73, respectively, using 30-min instantaneous energy flux data but 0.87 and 0.99, respectively, using daily average energy flux data. Therefore, the energy closure status is related to the time scale that is used for the study. The variation in the surface energy budget at the two sites was similar: The sensible heat flux (Hs) was relatively high in spring and reduced in summer but gradually increased in autumn. The latent heat flux (LE) was higher in summer and autumn but lower in winter and spring. Comparably, the starting time for the significant increase in LE occurred earlier at the Tanggula site than that at the BJ site, because the freezing and thawing progress of the active layer of permafrost at Tanggula site significantly affected the Hs and LE distributions, but the freezing and thawing processes of the soil at BJ site did not significantly affect the Hs and LE distributions. The monsoon significantly affected the variation in Hs and LE at both the BJ and Tanggula sites. Regarding the diurnal variation of the energy budget at the two sites, the daily maximum of net radiation (Rn) occurred at approximately 14:00 Beijing Time, and the daily maximum of ground heat flux (G0) was earlier than those of Hs and LE. The albedo and Bowen ratio for the two sites were both low in summer but high in winter. The albedo increased significantly but the Bowen ratio became lower or even negative when the surface was covered with deep snow.

  6. Dynamics of interacting dark energy

    CERN Document Server

    Caldera-Cabral, Gabriela; Urena-Lopez, L Arturo

    2008-01-01

    Dark energy and dark matter are only indirectly measured via their gravitational effects. It is possible that there is an exchange of energy within the dark sector, and this offers an interesting alternative approach to the coincidence problem. We consider two broad classes of interacting models where the energy exchange is a linear combination of the dark sector densities. The first class has been previously investigated, but we define new variables and find a new exact solution, which allows for a more direct, transparent and comprehensive analysis. The second class has not been investigated in general form before. We give general conditions on the parameters in both classes to avoid unphysical behavior (such as negative energy densities).

  7. The Dynamics of Wave Energy

    OpenAIRE

    Ringwood, John

    2006-01-01

    This paper examines the challenges of efficiently harnessing wave energy. A variety of energy conversion device types is reviewed and a generic heaving buoy device selected for detailed examination. A number of modelling and control challenges are detailed and a hierarchical control structure is indicated. Both potable water production and electricity generation are included as possible uses of such devices and each presents separate control challenges.

  8. Energy-Performance-Based Design-Build Process: Strategies for Procuring High-Performance Buildings on Typical Construction Budgets: Preprint

    Energy Technology Data Exchange (ETDEWEB)

    Scheib, J.; Pless, S.; Torcellini, P.

    2014-08-01

    NREL experienced a significant increase in employees and facilities on our 327-acre main campus in Golden, Colorado over the past five years. To support this growth, researchers developed and demonstrated a new building acquisition method that successfully integrates energy efficiency requirements into the design-build requests for proposals and contracts. We piloted this energy performance based design-build process with our first new construction project in 2008. We have since replicated and evolved the process for large office buildings, a smart grid research laboratory, a supercomputer, a parking structure, and a cafeteria. Each project incorporated aggressive efficiency strategies using contractual energy use requirements in the design-build contracts, all on typical construction budgets. We have found that when energy efficiency is a core project requirement as defined at the beginning of a project, innovative design-build teams can integrate the most cost effective and high performance efficiency strategies on typical construction budgets. When the design-build contract includes measurable energy requirements and is set up to incentivize design-build teams to focus on achieving high performance in actual operations, owners can now expect their facilities to perform. As NREL completed the new construction in 2013, we have documented our best practices in training materials and a how-to guide so that other owners and owner's representatives can replicate our successes and learn from our experiences in attaining market viable, world-class energy performance in the built environment.

  9. Turbulent kinetic energy budget in the boundary layer developing over an urban-like rough wall using PIV

    Science.gov (United States)

    Blackman, Karin; Perret, Laurent; Calmet, Isabelle; Rivet, Cédric

    2017-08-01

    In the present work, a boundary layer developing over a rough-wall consisting of staggered cubes with a plan area packing density λp = 25% is studied within the wind tunnel using Particle Image Velocimetry (PIV) to investigate the Turbulent Kinetic Energy (TKE) budget. To access the full TKE budget, an estimation of the dissipation (ɛ) using both the transport equation of the resolved-scale kinetic energy and Large-Eddy (LE) PIV models based on the use of a subgrid-scale model following the methodology used in large-eddy simulations is employed. A low-pass filter, larger than the Taylor microscale, is applied to the data prior to the computation of the velocity gradients ensuring a clear cutoff in the inertial range where the models are valid. The presence of the cube roughness elements has a significant influence on the TKE budget due to the region of strong shear that develops over the cubes. The shear layer is shown to produce and dissipate energy, as well as transport energy through advection, turbulent transport, and pressure transport. The recirculation region that forms through the interaction of the shear layer and the canopy layer, which is the region below the height of the cube roughness, creates rapid longitudinal evolution of the mean flow thereby inducing weak production. Finally, through stochastic estimation of the conditional average, it is shown that localized regions of backscatter (energy transfer from unresolved to resolved scales) and forward scatter (energy transfer from resolved to unresolved scales) occur as a result of coherent vortical structures.

  10. The influence of main ecological and environmental factors on the energy budget of Schlegel's black rockfish Sebastes schlegeli

    Institute of Scientific and Technical Information of China (English)

    SUN Yao; ZHENG Bing; ZHANG Bo; TANG Qisheng

    2007-01-01

    In the Maidao Ecological Laboratory of the Huanghai Sea Fisheries Research Institute in 1998~2000, the continuous flow-through method was adopted to determine the energy budget components and models of Schlegel's black rockfish under different ecological and environmental factors, such as temperature, food species, body mass and feeding level, etc. The body mass of test fish ranged from 21.2 to 224.5 g. The specific growth rate tended to invert "U" change with temperature increase. The ecological conversion efficiency showed the same trend as temperature and feeding level rise. Only the specific growth rate tended to decelerate the increment with the rise of feeding level. From the above quantitative relationships, the maximum and optimal growth temperatures could be obtained as 17.5 and 16.2 ℃, and the maintenance feeding rate and optimum feeding rate as 0.8% and 4.1% of the body mass. The specific growth rate and ecological conversion coefficient showed a decelerating decrease trend with body mass increment. The small-sized fish food was more advantageous to the feeding level increase in comparison with the small-sized shrimp food, which led to the increase of growth, metabolism and excretion, but had no significant influence on the ecological conversion coefficient. All of temperature, feeding level, body mass and food species can obviously change the energy budget models. The assigning rate of growth energy tended to change along the invert "U" curve with the increase of temperature and feeding level, and decrease with the body mass increase, but the assigning rates of metabolism energy and excretion energy were quite reverse. These relationships could be quantitatively described as quadratic or power function curve. If the above relationships proved true to other marine fish, the establishment of energy budget model of the same fish under different conditions can be largely simplified.

  11. On the relationship of the earth radiation budget to the variability of atmospheric available potential and kinetic energies

    Science.gov (United States)

    Randel, David L.; Vonder Haar, Thomas H.

    1990-01-01

    The zonal and eddy kinetics energies and available potential energies are examined for both the Northern and the Southern Hemispheres, using a data set produced by 8 years of continuous simultaneous observations of the circulation parameters and measurements of the earth radiation budget (ERB) from the Nimbus-7 ERB experiment. The relationships between the seasonal cycles in ERB and those of the energetics are obtained, showing that the solar annual cycle accounts for most of the seasonal variability. It was found that the ERB midlatitude gradients of the net balance and the outgoing radiation lead the annual cycle of the energetics by 2-3 weeks.

  12. On the relationship of the earth radiation budget to the variability of atmospheric available potential and kinetic energies

    Science.gov (United States)

    Randel, David L.; Vonder Haar, Thomas H.

    1990-01-01

    The zonal and eddy kinetics energies and available potential energies are examined for both the Northern and the Southern Hemispheres, using a data set produced by 8 years of continuous simultaneous observations of the circulation parameters and measurements of the earth radiation budget (ERB) from the Nimbus-7 ERB experiment. The relationships between the seasonal cycles in ERB and those of the energetics are obtained, showing that the solar annual cycle accounts for most of the seasonal variability. It was found that the ERB midlatitude gradients of the net balance and the outgoing radiation lead the annual cycle of the energetics by 2-3 weeks.

  13. Energy Management Dynamic Control Topology In MANET

    Science.gov (United States)

    Madhusudan, G.; Kumar, TNR

    2017-08-01

    Topology management via per-node transmission power adjustment has been shown effective in extending network lifetime. The existing algorithms constructs static topologies which fail to take the residual energy of network nodes, and cannot balance energy consumption efficiently. To address this problem, a Light Weighted Distributed Topology Control algorithm EMDCT(Energy Management Dynamic Control Topology ) is proposed in this paper. Based on the link metric of the network, both the energy consumption rate level and residual energy levels at the two end nodes are considered. EMDCT generates a Dynamic Topology that changes with the variation of node energy without the aid of location information, each node determines its transmission power according to local network information, which reduces the overhead complexity of EMDCT greatly. The experiment results show that EMDCT preserves network connectivity and manitains minimum-cost property of the network also it can extend network lifetime more remarkably.

  14. Improved predictive ability of climate-human-behaviour interactions with modifications to the COMFA outdoor energy budget model

    Science.gov (United States)

    Vanos, J. K.; Warland, J. S.; Gillespie, T. J.; Kenny, N. A.

    2012-11-01

    The purpose of this paper is to implement current and novel research techniques in human energy budget estimations to give more accurate and efficient application of models by a variety of users. Using the COMFA model, the conditioning level of an individual is incorporated into overall energy budget predictions, giving more realistic estimations of the metabolism experienced at various fitness levels. Through the use of VO2 reserve estimates, errors are found when an elite athlete is modelled as an unconditioned or a conditioned individual, giving budgets underpredicted significantly by -173 and -123 W m-2, respectively. Such underprediction can result in critical errors regarding heat stress, particularly in highly motivated individuals; thus this revision is critical for athletic individuals. A further improvement in the COMFA model involves improved adaptation of clothing insulation ( I cl), as well clothing non-uniformity, with changing air temperature ( T a) and metabolic activity ( M act). Equivalent T a values (for I cl estimation) are calculated in order to lower the I cl value with increasing M act at equal T a. Furthermore, threshold T a values are calculated to predict the point at which an individual will change from a uniform I cl to a segmented I cl (full ensemble to shorts and a T-shirt). Lastly, improved relative velocity ( v r) estimates were found with a refined equation accounting for the degree angle of wind to body movement. Differences between the original and improved v r equations increased with higher wind and activity speeds, and as the wind to body angle moved away from 90°. Under moderate microclimate conditions, and wind from behind a person, the convective heat loss and skin temperature estimates were 47 W m-2 and 1.7°C higher when using the improved v r equation. These model revisions improve the applicability and usability of the COMFA energy budget model for subjects performing physical activity in outdoor environments

  15. Age, budget and dynamics of an active salt extrusion in Iran

    Science.gov (United States)

    Talbot, C. J.; Jarvis, R. J.

    The Hormuz salt of Kuh-e-Namak, Iran began rising through its Phanerozoic cover in Jurassic times and had surfaced by Cretaceous times. In Miocene times, the still-active Zagros folds began to develop and the salt is still extruding to feed a massive topographic dome and two surface flows of salt which have previously been called salt glaciers but are here called namakiers. Two crude but independent estimates for the rate of salt extrusion and loss are shown to balance the salt budget if the current salt dynamics are assumed to be in steady state. First, to replace the extrusive salt likely to be lost in solution in the annual rainfall, the salt must rise at an average velocity of about 11 cm a -1. Second, the foliation pattern shows that the extruding (and partially dissolved) salt column spreads under its own weight. The maximum height of the salt dome is consistent with a viscous fluid with a viscosity of 2.6 × 10 17 poises extruding from its orifice at a rate of almost 17 cm a -1. Both estimates are consistent in indicating that salt can extrude onto the surface 42-85 times faster than the average long term rate at which salt diapirs rise to the surface. The structure, fabrics, textures and deformation mechanisms of the impure halite all change along the path of the extrusive salt from the dome down the length of both namakiers. Such changes tend to occur when the flowing salt encounters changes in its boundary conditions, and the recognition of buried namakiers is discussed in the light of such observations. Episodes of salt flow at a rate of 0.5 m per day have been measured along the margin of the N namakier after significant rain showers. Such brief episodes of rapid flow alternate with long periods when the namakier is dry and stationary. The shape of the colour bands cropping out on the N namakier indicate that the flow over the surface of impure salt with a mylonitic texture obeys a power law with n ≈ 3. Although the reported annual rainfall has the

  16. The Net Energy Budget at the Surface Interface of the "Cold Tongue" Region

    Science.gov (United States)

    Bentamy, Abderrahim; Pinker, Rachel; Zhang, Banglin; Ma, Yingtao

    2016-04-01

    The southern tropical Pacific region also known as the "cold tongue" region is of great interest in terms of understanding the atmosphere-ocean coupling, and the observed strong seasonal cycle in sea surface temperature. The primary goal of our study is to investigate the spatial and temporal variability of air-sea interaction through the analysis of the net heat budget over the "cold tongue" region. Such analysis requires high quality heat budget estimates which are impacted by the complex and extensive low-level stratocumulus clouds in this region. The accuracy at which current satellite and numerical model methods can estimate this net heat budget is of interest. In this paper, the heat budget at the ocean-atmosphere interface in a region bound by 0o S - 30o S, 110o W - 70o W has been derived using satellite observations and compared to in situ measurements and to predictions from numerical models. The approach is based on multi-satellite sensors, buoy observations and numerical analyses. The fluxes are generated at daily and monthly time scales for a 10 year period (2002-2012) at a nominal 10 resolution (some parameters are available at higher resolution). Once the metrics on the accuracy of the satellite estimates are known, they can serve as "ground truth" for evaluating numerical models.

  17. Cloud Effects on Meridional Atmospheric Energy Budget Estimated from Clouds and the Earth's Radiant Energy System (CERES) Data

    Science.gov (United States)

    Kato, Seiji; Rose, Fred G.; Rutan, David A.; Charlock, Thomas P.

    2008-01-01

    The zonal mean atmospheric cloud radiative effect, defined as the difference of the top-of-atmosphere (TOA) and surface cloud radiative effects, is estimated from three years of Clouds and the Earth's Radiant Energy System (CERES) data. The zonal mean shortwave effect is small, though it tends to be positive (warming). This indicates that clouds increase shortwave absorption in the atmosphere, especially in midlatitudes. The zonal mean atmospheric cloud radiative effect is, however, dominated by the longwave effect. The zonal mean longwave effect is positive in the tropics and decreases with latitude to negative values (cooling) in polar regions. The meridional gradient of cloud effect between midlatitude and polar regions exists even when uncertainties in the cloud effect on the surface enthalpy flux and in the modeled irradiances are taken into account. This indicates that clouds increase the rate of generation of mean zonal available potential energy. Because the atmospheric cooling effect in polar regions is predominately caused by low level clouds, which tend to be stationary, we postulate that the meridional and vertical gradients of cloud effect increase the rate of meridional energy transport by dynamics in the atmosphere from midlatitude to polar region, especially in fall and winter. Clouds then warm the surface in polar regions except in the Arctic in summer. Clouds, therefore, contribute in increasing the rate of meridional energy transport from midlatitude to polar regions through the atmosphere.

  18. Estimating changes in heat energy stored within a column of wetland surface water and factors controlling their importance in the surface energy budget

    Science.gov (United States)

    Shoemaker, W.B.; Sumner, D.M.; Castillo, A.

    2005-01-01

    [1] Changes in heat energy stored within a column of wetland surface water can be a considerable component of the surface energy budget, an attribute that is demonstrated by comparing changes in stored heat energy to net radiation at seven sites in the wetland areas of southern Florida, including the Everglades. The magnitude of changes in stored heat energy approached the magnitude of net radiation more often during the winter dry season than during the summer wet season. Furthermore, the magnitude of changes in stored heat energy in wetland surface water generally decreased as surface energy budgets were upscaled temporally. A new method was developed to estimate changes in stored heat energy that overcomes an important data limitation, namely, the limited spatial and temporal availability of water temperature measurements. The new method is instead based on readily available air temperature measurements and relies on the convolution of air temperature changes with a regression-defined transfer function to estimate changes in water temperature. The convolution-computed water temperature changes are used with water depths and heat capacity to estimate changes in stored heat energy within the Everglades wetland areas. These results likely can be adapted to other humid subtropical wetlands characterized by open water, saw grass, and rush vegetation type communities. Copyright 2005 by the American Geophysical Union.

  19. Investigating effect of environmental controls on dynamics of CO2 budget in a subtropical estuarial marsh wetland ecosystem

    Science.gov (United States)

    Lee, Sung-Ching; Fan, Chao-Jung; Wu, Zih-Yi; Juang, Jehn-Yih

    2015-02-01

    In this study, we quantified the ecosystem-scale CO2 exchange of two different but typical low-latitude vegetation types, para grass and reed, in a subtropical wetland ecosystem by integrating flux observation with the parameterization of environmental variables. In addition, we explored how seasonal dynamics of environmental factors affected variations in CO2 budget. The results suggest that gross primary production (GPP, in the order of 1700 gC m-2 yr-1) of CO2 was higher in this site than in previous studies of northern peatlands and estuarial wetlands because of the direct effect of environmental factors. Temperature and radiation had a larger effect than water status (soil moisture content and vapor pressure deficit) on GPP for the two low-latitude ecosystems, which differ from the results for high-latitude regions. Environmental variables had a strong but different impact on the CO2 budget for para grass and reed areas. This diversity led to different potential shifts and trends of biomass accumulation and distribution of these two typical low-latitude vegetation types under different scenarios of environmental change. The findings from this study can sufficiently provide quantitative understanding of CO2 budgets in low-latitude wetlands.

  20. Surface energy budget of landfast sea ice during the transitions from winter to snowmelt and melt pond onset

    DEFF Research Database (Denmark)

    Else, B.G.T.; Papakyriakou, T.N.; Raddatz, R.

    2014-01-01

    Relatively few sea ice energy balance studies have successfully captured the transition season of warming, snowmelt, and melt pond formation. In this paper, we report a surface energy budget for landfast sea ice that captures this important period. The study was conducted in the Canadian Arctic......, but it delivered enough energy to significantly hasten melt onset had it occurred earlier in the season. Changes in the frequency, duration, and timing of synoptic-scale weather events that deliver clouds and/or strong turbulent heat fluxes may be important in explaining observed changes in sea ice melt onset......) combined with the seasonal increase in incoming shortwave radiation then triggered snowmelt onset. Melt progressed with a rapid reduction in albedo and attendant increases in shortwave energy absorption, resulting in melt pond formation 8 days later. The key role of longwave radiation in initiating melt...

  1. Interannual variability in the surface energy budget and evaporation over a large southern inland water in the United States

    Science.gov (United States)

    Zhang, Qianyu; Liu, Heping

    2013-05-01

    Understanding how the surface energy budget and evaporation over inland waters respond to climate change and variability remains limited. Here we report 2 year measurements of the surface energy budget using the eddy covariance method over Ross Barnett Reservoir, Mississippi, USA, for 2008 and 2009. Annual mean sensible (H) and latent (LE) heat fluxes in 2008 were 9.5%, and 10.0% greater than in 2009, respectively. Most of the interannual variations in the surface energy fluxes and meteorological variables primarily occurred in the cool seasons from October to March, which was enhanced by frequent large wind events associated with cold front passages. These large wind events greatly promoted H and LE exchange and produced H and LE pulses that increased variations in H and LE between these two cool seasons. In the warm seasons from April to September, H and LE pulses were also present, which largely increased variations in LE and dampened those in H between the two warm seasons. The H and LE pulses contributed to approximately 50% of the annual H and 28% of the annual LE, although they only covered about 16% of the entire year. The interannual variations in H and LE pulses contributed to about 78% of the interannual variations in H and 40% of those in LE. Our results imply that the increased interannual variability in cold front activities as a result of climate change would amplify interannual variations in the evaporation and the surface energy exchange over inland waters in this region.

  2. Schwinger's Dynamical Casimir Effect Bulk Energy Contribution

    CERN Document Server

    Carlson, C E; Pérez-Mercader, J; Visser, M; Carlson, C E; Carlson, Carl E.; Molina-Paris, Carmen; Perez-Mercader, Juan; Visser, Matt

    1997-01-01

    Schwinger's Dynamical Casimir Effect is one of several candidate explanations for sonoluminescence. Recently, several papers have claimed that Schwinger's estimate of the Casimir energy involved is grossly inaccurate. In this letter, we show that these calculations omit the crucial volume term. When the missing term is correctly included one finds full agreement with Schwinger's result for the Dynamical Casimir Effect. We have nothing new to say about sonoluminescence itself except to affirm that the Casimir effect is energetically adequate as a candidate explanation. Schwinger's Dynamical Casimir Effect is one of several candidate explanations for sonoluminescence. Recently, several papers have claimed that Schwinger's estimate of the Casimir energy involved is grossly inaccurate. In this letter, we show that these calculations omit the crucial volume term. When the missing term is correctly included one finds full agreement with Schwinger's result for the Dynamical Casimir Effect. We have nothing new to say...

  3. Constraining the dynamics of the water budget at high spatial resolution in the world's water towers using models and remote sensing data; Snake River Basin, USA

    Science.gov (United States)

    Watson, K. A.; Masarik, M. T.; Flores, A. N.

    2016-12-01

    Mountainous, snow-dominated basins are often referred to as the water towers of the world because they store precipitation in seasonal snowpacks, which gradually melt and provide water supplies to downstream communities. Yet significant uncertainties remain in terms of quantifying the stores and fluxes of water in these regions as well as the associated energy exchanges. Constraining these stores and fluxes is crucial for advancing process understanding and managing these water resources in a changing climate. Remote sensing data are particularly important to these efforts due to the remoteness of these landscapes and high spatial variability in water budget components. We have developed a high resolution regional climate dataset extending from 1986 to the present for the Snake River Basin in the northwestern USA. The Snake River Basin is the largest tributary of the Columbia River by volume and a critically important basin for regional economies and communities. The core of the dataset was developed using a regional climate model, forced by reanalysis data. Specifically the Weather Research and Forecasting (WRF) model was used to dynamically downscale the North American Regional Reanalysis (NARR) over the region at 3 km horizontal resolution for the period of interest. A suite of satellite remote sensing products provide independent, albeit uncertain, constraint on a number of components of the water and energy budgets for the region across a range of spatial and temporal scales. For example, GRACE data are used to constrain basinwide terrestrial water storage and MODIS products are used to constrain the spatial and temporal evolution of evapotranspiration and snow cover. The joint use of both models and remote sensing products allows for both better understanding of water cycle dynamics and associated hydrometeorologic processes, and identification of limitations in both the remote sensing products and regional climate simulations.

  4. The effects of divergent and nondivergent winds on the kinetic energy budget of a mid-latitude cyclone - A case study

    Science.gov (United States)

    Chen, T.-C.; Alpert, J. C.; Schlatter, T. W.

    1978-01-01

    The magnitude of the divergent component of the wind is relatively small compared to that of the nondivergent component in large-scale atmospheric flows; nevertheless, it plays an important role in the case of explosive cyclogenesis examined here. The kinetic energy budget for the life cycle of an intense, developing cyclone over North America is calculated. The principal kinetic energy source is the net horizontal transport across the boundaries of the region enclosing the cyclone. By investigating the relative importance of the divergent and nondivergent wind components in the kinetic energy budget, it was found, as expected, that neglecting the divergent wind component in calculating the magnitude of the kinetic energy is of little consequence, but that the horizontal flux convergence and generation of kinetic energy depend crucially upon the divergent component. Modification of the divergent wind component can result in significant changes in the kinetic energy budget of the synoptic system.

  5. Dynamic cache resources allocation for energy efficiency

    Institute of Scientific and Technical Information of China (English)

    CHEN Li-ming; ZOU Xue-cheng; LEI Jian-ming; LIU Zheng-lin

    2009-01-01

    This article proposes a mechanism of low overhead and less runtime, termed dynamic cache resources allocation (DCRA), which allocates each application with required cache resources. The mechanism collects cache hit-miss information at runtime and then analyzes the information and decides how many cache resources should be allocated to the current executing application. The amount of cache resources varies dynamically to reduce the total number of misses and energy consumption. The study of several applications from SPEC2000 shows that significant energy saving is achieved for the application based on the DCRA with an average of 39% savings.

  6. Impact of copper application on soil metabolism, energy budget and formation of stable aggregates by anecic earthworm in tea plantations.

    Science.gov (United States)

    Patnaik, Aliva

    2002-02-01

    The preparation of daily energy budget of earth worm Lampito mauritii showed (i) decrease in consumption by about 66%, (ii) decrease of egestion 97%, (iii) decrease in growth by 80%, and (iv) enhancement in maintenance cost by about 31.5% on exposure to 8 ppm copper in comparison to zero level exposure. The stable aggregate formations also decreased by 67.6% at 8 ppm copper as compared to zero level exposure. Two way ANOVA showed significant decrease in stable aggregate formation and biomass at 5% level of significance on exposure to 8 ppm copper. The soil metabolism also increased under the negative impact of copper.

  7. Budget spending and economic growth in Croatia - Dynamics and relathionships over the past two decades

    Directory of Open Access Journals (Sweden)

    Helena Blažić

    2011-12-01

    Full Text Available The objective of this research is to analyze the relationship between government budget spending and the effect on the growth and structure of the GDP of Croatia during the past two decades. The starting working assumption (hypothesis is that the volume of total budget expenditure (including the foreign borrowing has not been realizing appropriate effect on GDP growth. In the analysis of these relationships we primarily use the method of vector autoregressions (VAR. The main result of the analysis showed that, in accordance with theoretical assumptions, the structure of expenditures is essential for the effects of budgetary spending on economic growth. We determine the positive effects of investment spending and purchases of goods and services and the negative effects of other categories of current spending. The reduction of capital expenditures during the recession presents a particularly adverse trend, which reduces the rate of growth of the economy in the long and short term. A fundamental conclusion of the research is that the budget expenditures have not adequately affected the GDP growth. Therefore, it is possible to affect the economic growth by changing the structure of budgetary spending, as well as directing public borrowing to investment financing.

  8. Distributions of available potential and kinetic energy budget quantities associated with wintertime cyclone activity along the eastern coasts of Asia and North America

    OpenAIRE

    ZAPOTOCNY, JOHN V.

    2011-01-01

    Available potential energy and kinetic energy budget quantities are examined during a two-week period of the Global Weather Experiment (GWE) winter season (14–28 February 1979) for regions encompassing the cyclogenetically active eastern coasts of Asia and North America. Twice daily values of vertically integrated available potential energy generation, kinetic energy generation, and kinetic energy boundary flux are produced using gridded isentropic data derived from the National Meteorologica...

  9. Energy efficiency of a dynamic glazing system

    Energy Technology Data Exchange (ETDEWEB)

    Lollini, R. [Institute for Renewable Energy, EURAC Research, Viale Druso 1, I-39100 Bolzano (Italy); Danza, L.; Meroni, I. [ITC-CNR, Construction Technologies Institute - Italian National Research Council, Via Lombardia, 49 - 20098 San Giuliano Milanese (MI) (Italy)

    2010-04-15

    The reduction of air-conditioning energy consumptions is one of the main indicators to act on when improving the energy efficiency in buildings. In the case of advanced technological buildings, a meaningful contribution to the thermal loads and the energy consumptions reduction could depend on the correct configuration and management of the envelope systems. In recent years, the architectural trend toward highly transparent all-glass buildings presents a unique challenge and opportunity to advance the market for emerging, smart, dynamic window and dimmable daylighting control technologies (). A prototype dynamic glazing system was developed and tested at ITC-CNR; it is aimed at actively responding to the external environmental loads. Both an experimental campaign and analyses by theoretical models were carried out, aimed at evaluating the possible configurations depending on different weather conditions in several possible places. Therefore, the analytical models of the building-plant system were defined by using a dynamic energy simulation software (EnergyPlus). The variables that determine the system performance, also influenced by the boundary conditions, were analysed, such as U- and g-value; they concern both the morphology of the envelope system, such as dimensions, shading and glazing type, gap airflow thickness, in-gap airflow rate, and management, in terms of control algorithm parameters tuning fan and shading systems, as a function of the weather conditions. The configuration able to provide the best performances was finally identified by also assessing such performances, integrating the dynamic system in several building types and under different weather conditions. The dynamic envelope system prototype has become a commercial product with some applications in facade systems, curtain walls and windows. The paper describes the methodological approach to prototype development and the main results obtained, including simulations of possible applications on

  10. Heat and turbulent kinetic energy budgets for surface layer cooling induced by the passage of Hurricane Frances (2004)

    Science.gov (United States)

    Huang, Peisheng; Sanford, Thomas B.; Imberger, JöRg

    2009-12-01

    Heat and turbulent kinetic energy budgets of the ocean surface layer during the passage of Hurricane Frances were examined using a three-dimensional hydrodynamic model. In situ data obtained with the Electromagnetic-Autonomous Profiling Explorer (EM-APEX) floats were used to set up the initial conditions of the model simulation and to compare to the simulation results. The spatial heat budgets reveal that during the hurricane passage, not only the entrainment in the bottom of surface mixed layer but also the horizontal water advection were important factors determining the spatial pattern of sea surface temperature. At the free surface, the hurricane-brought precipitation contributed a negligible amount to the air-sea heat exchange, but the precipitation produced a negative buoyancy flux in the surface layer that overwhelmed the instability induced by the heat loss to the atmosphere. Integrated over the domain within 400 km of the hurricane eye on day 245.71 of 2004, the rate of heat anomaly in the surface water was estimated to be about 0.45 PW (1 PW = 1015 W), with about 20% (0.09 PW in total) of this was due to the heat exchange at the air-sea interface, and almost all the remainder (0.36 PW) was downward transported by oceanic vertical mixing. Shear production was the major source of turbulent kinetic energy amounting 88.5% of the source of turbulent kinetic energy, while the rest (11.5%) was attributed to the wind stirring at sea surface. The increase of ocean potential energy due to vertical mixing represented 7.3% of the energy deposited by wind stress.

  11. Integrating MODIS images in a water budget model for dynamic functioning and drought simulation of a Mediterranean forest in Tunisia

    Directory of Open Access Journals (Sweden)

    H. Chakroun

    2012-05-01

    Full Text Available The use of remote sensing at different spatio-temporal resolutions is being common during the last decades since sensors offer many inputs to water budget estimation. Various water balance models use the LAI as a parameter for accounting water interception, evapotranspiration, runoff and available ground water. The objective of the present work is to improve vegetation stress monitoring at regional scale for a natural forested ecosystem. LAI-MODIS and spatialized vegetation, soil and climatic data have been integrated in a water budget model that simulates evapotranspiration and soil water content at daily step. We first explore LAI-MODIS in the specific context of Mediterranean natural ecosystem. Results showed that despite coarse resolution of LAI-MODIS product (1 km, it was possible to discriminate evergreen and coniferous vegetation and that LAI values are influenced by underlying soil capacity of water holding. The dynamic of vegetation has been integrated into the water budget model by weekly varying LAI-MODIS. Results of simulations were analysed in terms of actual evapotranspoiration, deficit of soil water to field capacity and vegetation stress index based on actual and potential evapotranspiration. Comparing dynamic LAI variation, afforded by MODIS, to a hypothetic constant LAI all over the year correspond to 30% of fAPAR increase. A sensitivity analysis of simulation outputs to this fAPAR variation reveals that increase of both deficit of soil water to field capacity and stress index are respectively 18% and 27%, (in terms of RMSE, these variations are respectively 1258 mm yr−1 and 11 days yr−1. These results are consistent with previous studies led at local scale showing that LAI increase is accompanied by stress conditions increase in Mediterranean natural ecosystems. In this study, we also showed that spatial modelisation of drought conditions based on water budget simulations is an adequate tool for

  12. Post-common envelope binaries from SDSS - XVI. Long orbital period systems and the energy budget of CE evolution

    CERN Document Server

    Rebassa-Mansergas, A; Schreiber, M R; Gaensicke, B T; Southworth, J; Gomez-Moran, A Nebot; Tappert, C; Koester, D; Pyrzas, S; Papadaki, C; Schmidtobreick, L; Schwope, A; Toloza, O

    2012-01-01

    Virtually all close compact binary stars are formed through common-envelope (CE) evolution. It is generally accepted that during this crucial evolutionary phase a fraction of the orbital energy is used to expel the envelope. However, it is unclear whether additional sources of energy, such as the recombination energy of the envelope, play an important role. Here we report the discovery of the second and third longest orbital period post-common envelope binaries (PCEBs) containing white dwarf (WD) primaries, i.e. SDSSJ121130.94-024954.4 (Porb = 7.818 +- 0.002 days) and SDSSJ222108.45+002927.7 (Porb = 9.588 +- 0.002 days), reconstruct their evolutionary history, and discuss the implications for the energy budget of CE evolution. We find that, despite their long orbital periods, the evolution of both systems can still be understood without incorporating recombination energy, although at least small contributions of this additional energy seem to be likely. If recombination energy significantly contributes to the...

  13. Fundamentally excited flow past a surface-mounted rib. Part II: Kinetic energy budget details

    Indian Academy of Sciences (India)

    P K Panigrahi

    2001-10-01

    This paper presents the detailed turbulent kinetic energy budget and higher order statistics of flow behind a surface-mounted rib with and without superimposed acoustic excitation. Pattern recognition technique is used to determine the large-scale structure magnitude. It is observed that most of the turbulence contributions after the reattachment region are from the large-scale structures contrary to the belief that mostly random turbulent structures are present after reattachment. The dissipation is not a small-scale phenomena only. It may result due to the interaction between large-scale structures. From the results of higher order moments, the outer edge of the shear layer is observed to be non-Gaussian in nature with significant deviation from the Gaussian skewness and flatness value. The kinetic energy budget results show positive intermodal production in the outer edge of the shear layer indicating the presence of back scattering. The non-Gaussian velocity distribution, ejection motions and back-scattering present in the outer shear layer may be conjectured to be correlated with each other.

  14. A Hierarchy of Energy- and Flux-Budget (EFB) Turbulence Closure Models for Stably-Stratified Geophysical Flows

    Science.gov (United States)

    Zilitinkevich, S. S.; Elperin, T.; Kleeorin, N.; Rogachevskii, I.; Esau, I.

    2013-03-01

    Here we advance the physical background of the energy- and flux-budget turbulence closures based on the budget equations for the turbulent kinetic and potential energies and turbulent fluxes of momentum and buoyancy, and a new relaxation equation for the turbulent dissipation time scale. The closure is designed for stratified geophysical flows from neutral to very stable and accounts for the Earth's rotation. In accordance with modern experimental evidence, the closure implies the maintaining of turbulence by the velocity shear at any gradient Richardson number Ri, and distinguishes between the two principally different regimes: "strong turbulence" at {Ri ≪ 1} typical of boundary-layer flows and characterized by the practically constant turbulent Prandtl number Pr T; and "weak turbulence" at Ri > 1 typical of the free atmosphere or deep ocean, where Pr T asymptotically linearly increases with increasing Ri (which implies very strong suppression of the heat transfer compared to the momentum transfer). For use in different applications, the closure is formulated at different levels of complexity, from the local algebraic model relevant to the steady-state regime of turbulence to a hierarchy of non-local closures including simpler down-gradient models, presented in terms of the eddy viscosity and eddy conductivity, and a general non-gradient model based on prognostic equations for all the basic parameters of turbulence including turbulent fluxes.

  15. The captains of energy systems dynamics from an energy perspective

    CERN Document Server

    Prantil, Vincent C

    2015-01-01

    In teaching an introduction to transport or systems dynamics modeling at the undergraduate level, it is possible to lose pedagogical traction in a sea of abstract mathematics. What the mathematical modeling of time-dependent system behavior offers is a venue in which students can be taught that physical analogies exist between what they likely perceive as distinct areas of study in the physical sciences. We introduce a storyline whose characters are superheroes that store and dissipate energy in dynamic systems. Introducing students to the overarching conservation laws helps develop the analog

  16. Ocean warming and acidification modulate energy budget and gill ion regulatory mechanisms in Atlantic cod (Gadus morhua).

    Science.gov (United States)

    Kreiss, C M; Michael, K; Lucassen, M; Jutfelt, F; Motyka, R; Dupont, S; Pörtner, H-O

    2015-10-01

    Ocean warming and acidification are threatening marine ecosystems. In marine animals, acidification is thought to enhance ion regulatory costs and thereby baseline energy demand, while elevated temperature also increases baseline metabolic rate. Here we investigated standard metabolic rates (SMR) and plasma parameters of Atlantic cod (Gadus morhua) after 3-4 weeks of exposure to ambient and future PCO2 levels (550, 1200 and 2200 µatm) and at two temperatures (10, 18 °C). In vivo branchial ion regulatory costs were studied in isolated, perfused gill preparations. Animals reared at 18 °C responded to increasing CO2 by elevating SMR, in contrast to specimens at 10 °C. Isolated gills at 10 °C and elevated PCO2 (≥1200 µatm) displayed increased soft tissue mass, in parallel to increased gill oxygen demand, indicating an increased fraction of gill in whole animal energy budget. Altered gill size was not found at 18 °C, where a shift in the use of ion regulation mechanisms occurred towards enhanced Na(+)/H(+)-exchange and HCO3 (-) transport at high PCO2 (2200 µatm), paralleled by higher Na(+)/K(+)-ATPase activities. This shift did not affect total gill energy consumption leaving whole animal energy budget unaffected. Higher Na(+)/K(+)-ATPase activities in the warmth might have compensated for enhanced branchial permeability and led to reduced plasma Na(+) and/or Cl(-) concentrations and slightly lowered osmolalities seen at 18 °C and 550 or 2200 µatm PCO2 in vivo. Overall, the gill as a key ion regulation organ seems to be highly effective in supporting the resilience of cod to effects of ocean warming and acidification.

  17. Analysis of the climate variability on Lake Nasser evaporation based on the Bowen ratio energy budget method.

    Science.gov (United States)

    Elsawwaf, Mohamed; Willems, Patrick

    2012-04-01

    Variations in lake evaporation have a significant impact on the energy and water budgets of lakes. Understanding these variations and the role of climate is important for water resources management as well as predicting future changes in lake hydrology as a result of climate change. This study presents a comprehensive, 10-year analysis of seasonal, intraseasonal, and interannual variations in lake evaporation for Lake Nasser in South Egypt. Meteorological and lake temperature measurements were collected from an instrumented platform (Raft floating weather station) at 2 km upstream ofthe Aswan High Dam. In addition to that, radiation measurements at three locations on the lake: Allaqi, Abusembel and Arqeen (respectively at 75, 280 and 350 km upstream of the Aswan High Dam) are used. The data were analyzed over 14-day periods from 1995 to 2004 to provide bi-weekly energy budget estimates of evaporation rate. The mean evaporation rate for lake Nasser over the study period was 5.88 mm day(-1), with a coefficient of variation of 63%. Considerable variability in evaporation rates was found on a wide range of timescales, with seasonal changes having the highest coefficient of variation (32%), followed by the intraseasonal (28%) and interannual timescales (11.6%; for summer means). Intraseasonal changes in evaporation were primarily associated with synoptic weather variations, with high evaporation events tending to occur during incursions of cold, dry air (due, in part, to the thermal lag between air and lake temperatures). Seasonal variations in evaporation were largely driven by temperature and net energy advection, but are out-of-phase with changes in wind speed. On interannual timescales, changes in summer evaporation rates were strongly associated with changes in net energy advection and showed only moderate connections to variations in temperature or humidity.

  18. Simulating the carbon, water, energy budgets and greenhouse gas emissions of arctic soils with the ISBA land surface model

    Science.gov (United States)

    Morel, Xavier; Decharme, Bertrand; Delire, Christine

    2017-04-01

    Permafrost soils and boreal wetlands represent an important challenge for future climate simulations. Our aim is to be able to correctly represent the most important thermal, hydrologic and carbon cycle related processes in boreal areas with our land surface model ISBA (Masson et al, 2013). This is particularly important since ISBA is part of the CNRM-CM Climate Model (Voldoire et al, 2012), that is used for projections of future climate changes. To achieve this goal, we replaced the one layer original soil carbon module based on the CENTURY model (Parton et al, 1987) by a multi-layer soil carbon module that represents C pools and fluxes (CO2 and CH4), organic matter decomposition, gas diffusion (Khvorostyanov et al., 2008), CH4 ebullition and plant-mediated transport, and cryoturbation (Koven et al., 2009). The carbon budget of the new model is closed. The soil carbon module is tightly coupled to the ISBA energy and water budget module that solves the one-dimensional Fourier law and the mixed-form of the Richards equation explicitly to calculate the time evolution of the soil energy and water budgets (Boone et al., 2000; Decharme et al. 2011). The carbon, energy and water modules are solved using the same vertical discretization. Snowpack processes are represented by a multi-layer snow model (Decharme et al, 2016). We test this new model on a pair of monitoring sites in Greenland, one in a permafrost area (Zackenberg Ecological Research Operations, Jensen et al, 2014) and the other in a region without permafrost (Nuuk Ecological Research Operations, Jensen et al, 2013); both sites are established within the GeoBasis part of the Greenland Ecosystem Monitoring (GEM) program. The site of Chokurdakh, in a permafrost area of Siberia is is our third studied site. We test the model's ability to represent the physical variables (soil temperature and water profiles, snow height), the energy and water fluxes as well as the carbon dioxyde and methane fluxes. We also test the

  19. The impact of the global budget system on dynamics of dental manpower and utilization of dental services

    Science.gov (United States)

    Huang, Laura Yueh-Guey; Huang, Boyen

    2016-01-01

    Background: This study aimed to investigate dentists’ supply and practice patterns following the implementation of the global budget system in Taiwan. Materials and Methods: Data of reimbursement claims, municipal socioeconomic status and dental manpower were collected from the National Health Insurance administration, the Ministry of Internal Affair, and the Ministry of Health and Welfare, respectively. A multivariate linear regression method was used for data analysis. Results: A municipality that reported a higher percentage of tertiary educated population (t = 3.718, P amalgam restorations in total claims reduced from 19.82% to 17.94%, while the percentage of tooth-colored material restorations increased from 25.46% to 28.79%. Conclusion: This study has demonstrated a stabilizing effect of the global budget system on dynamics of dental manpower in Taiwan. A relationship between HHI and dentists’ move-out rate has been found. The relationship between municipal socioeconomic status and the density of dentists has also been confirmed. In addition, reduced utilization of amalgam restorations was accompanied by increased utilization of tooth-colored material restorations. Further investigations are indicated. PMID:27076827

  20. DOE FY 2010 Budget Request and Recovery Act Funding for Energy Research, Development, Demonstration, and Deployment: Analysis and Recommendations

    Energy Technology Data Exchange (ETDEWEB)

    Anadon, Laura Diaz; Gallagher, Kelly Sims; Bunn, Matthew

    2009-06-01

    The combination of the FY 2010 budget request for the Department of Energy (DOE) and the portion of the American Recovery and Reinvestment Act of 2009 (ARRA) funds likely to be available in 2010 would (assuming that they would be split evenly between FY 2010 and FY 2011) result in a doubling in funding available for energy research, development, and deployment (ERD and D) from $3.6 billion in FY 2009 to $7.2 billion in FY 2010. Without the stimulus funds, DOE ERD and D investments in FY 2010 would decrease very slightly when compared to FY 2009. Excluding the $7.5 billion for the Advanced Technology Vehicles Manufacturing Loans in FY 2009, the FY 2010 budget request for deployment represents a 33 percent decrease from the FY 2009 levels from $520 million to $350 million. This decrease is largely due to the large amounts of funds appropriated in ARRA for DOE deployment programs, or $23.6 billion, which are three times greater than those appropriated in the FY 2009 budget. These very substantial funding amounts, coupled with the broad range of institutional innovations the administration is putting in place and movement toward putting a price on carbon emissions, will help accelerate innovation for a broad range of energy technologies. DOE's Advanced Research Projects Agency-Energy (ARPA-E) and the Energy Innovation Hubs are important initiatives that could contribute to two weak points of the government's energy innovation effort, namely funding high-risk projects in transformational technologies and in companies that have not traditionally worked with the government and strengthening the integration of basic and applied research in priority areas. Increasing the funding for different types of energy storage research, providing some support for exploring opportunities in coal-to-liquids with carbon capture and storage (CCS) and coal-and-biomass-to-liquids with CCS, and reducing funding for fission RD and D are other actions that Congress could take in the

  1. Late Budgets

    DEFF Research Database (Denmark)

    Andersen, Asger Lau; Lassen, David Dreyer; Nielsen, Lasse Holbøll Westh

    The budget forms the legal basis of government spending. If a budget is not in place at the beginning of the fiscal year, planning as well as current spending are jeopardized and government shutdown may result. This paper develops a continuous-time war-of-attrition model of budgeting...... in a presidential style-democracy to explain the duration of budget negotiations. We build our model around budget baselines as reference points for loss averse negotiators. We derive three testable hypotheses: there are more late budgets, and they are more late, when fiscal circumstances change; when such changes...... are negative rather than positive; and when there is divided government. We test the hypotheses of the model using a unique data set of late budgets for US state governments, based on dates of budget approval collected from news reports and a survey of state budget o¢ cers for the period 1988...

  2. Late Budgets

    DEFF Research Database (Denmark)

    Andersen, Asger Lau; Lassen, David Dreyer; Nielsen, Lasse Holbøll Westh

    are negative rather than positive; and when there is divided government. We test the hypotheses of the model using a unique data set of late budgets for US state governments, based on dates of budget approval collected from news reports and a survey of state budget o¢ cers for the period 1988......The budget forms the legal basis of government spending. If a budget is not in place at the beginning of the fiscal year, planning as well as current spending are jeopardized and government shutdown may result. This paper develops a continuous-time war-of-attrition model of budgeting...... in a presidential style-democracy to explain the duration of budget negotiations. We build our model around budget baselines as reference points for loss averse negotiators. We derive three testable hypotheses: there are more late budgets, and they are more late, when fiscal circumstances change; when such changes...

  3. Different time and energy budgets of Lesser Snow Geese in rice-prairies and coastal marshes in southwest Louisiana

    Science.gov (United States)

    Jonsson, J.E.; Afton, A.D.

    2006-01-01

    Many bird species use human-made habitats and an important issue is whether these are equally suitable foraging habitats as are historical, natural habitats. Historically, Lesser Snow Geese (Chen caerulescens caerulescens, hereafter Snow Geese) wintered in coastal marshes in Louisiana but began using rice-prairies within the last 60 years. Time spent feeding was used as an indicator of habitat suitability and time and energy budgets of Snow Geese were compared between rice-prairies and coastal marshes in southwest Louisiana. Composite diets of Snow Geese have a lower energy density in the rice-prairies than in coastal marshes; thus, we predicted that Snow Geese would spend relatively more time feeding in rice-praires to obtain existence energy. However, time spent feeding was higher in coastal marshes and thus, not proportional to energy density of composite diets. Snow Geese in coastal marshes ingested less apparent metabolizable energy than did Snow Geese in rice-prairies. In rice-prairies, juveniles spent more time feeding than did adults; however, time spent feeding was similar between age classes in coastal marshes. Undeveloped foraging skills probably cause juvenile Snow Geese to forage less efficiently in coastal marshes than in rice-prairies. These findings are consistent with recent trends in Snow Goose numbers, which increased in rice-prairies but remained stable in coastal marshes.

  4. Validation and Benchmarking of a Practical Free Magnetic Energy and Relative Magnetic Helicity Budget Calculation in Solar Magnetic Structures

    CERN Document Server

    Moraitis, K; Georgoulis, M K; Archontis, V

    2014-01-01

    In earlier works we introduced and tested a nonlinear force-free (NLFF) method designed to self-consistently calculate the free magnetic energy and the relative magnetic helicity budgets of the corona of observed solar magnetic structures. The method requires, in principle, only a single, photospheric or low-chromospheric, vector magnetogram of a quiet-Sun patch or an active region and performs calculations in the absence of three-dimensional magnetic and velocity-field information. In this work we strictly validate this method using three-dimensional coronal magnetic fields. Benchmarking employs both synthetic, three-dimensional magnetohydrodynamic simulations and nonlinear force-free field extrapolations of the active-region solar corona. We find that our time-efficient NLFF method provides budgets that differ from those of more demanding semi-analytical methods by a factor of ~3, at most. This difference is expected from the physical concept and the construction of the method. Temporal correlations show mo...

  5. Mass and energy budgets of animals: Behavioral and ecological implications. Annual technical progress report, April 1, 1992--March 31, 1993

    Energy Technology Data Exchange (ETDEWEB)

    Porter, W.P.

    1993-07-01

    The common goal of these diverse projects is to understand the mechanisms of how animal populations respond to the continual changes in their environment in both time and space. Our models are mechanistic allowing us to explore how a wide array of environmental variables may determine individual performance. Large scale climate change and its effect on animal populations can be seen as quantitative extensions of biological responses to smaller scales of environmental variability. Changes in developmental rates or reproductive levels of individuals, extension or contraction of geographic ranges, and modification of community organization have all been documented in response to previous changes in habitats. We know from our biophysical work that some changes in function are driven by microclimate conditions directly, and some are mediated indirectly through ecological parameters such as the food supply. Our research is guided by a comprehensive conceptual scheme of the interaction of an animal with its environment. The physical and physiological properties of the organism, and the range of available microclimates, set bounds on the performance of organismal function, such as growth, reproduction, storage, and behavior. To leave the most offspring over a lifetime, animals must perform those functions in a way that maximizes the amount of resources devoted to reproduction. Maximizing the total size of the budget and minimizing those budget items not devoted to reproduction are crucial. Animals trade off among expenditures for current and future reproduction. Both water and energy are important, potentially limiting resources. Projects described here include empirical studies and theoretical models.

  6. Ultrafast Electron Dynamics in Solar Energy Conversion.

    Science.gov (United States)

    Ponseca, Carlito S; Chábera, Pavel; Uhlig, Jens; Persson, Petter; Sundström, Villy

    2017-08-23

    Electrons are the workhorses of solar energy conversion. Conversion of the energy of light to electricity in photovoltaics, or to energy-rich molecules (solar fuel) through photocatalytic processes, invariably starts with photoinduced generation of energy-rich electrons. The harvesting of these electrons in practical devices rests on a series of electron transfer processes whose dynamics and efficiencies determine the function of materials and devices. To capture the energy of a photogenerated electron-hole pair in a solar cell material, charges of opposite sign have to be separated against electrostatic attractions, prevented from recombining and being transported through the active material to electrodes where they can be extracted. In photocatalytic solar fuel production, these electron processes are coupled to chemical reactions leading to storage of the energy of light in chemical bonds. With the focus on the ultrafast time scale, we here discuss the light-induced electron processes underlying the function of several molecular and hybrid materials currently under development for solar energy applications in dye or quantum dot-sensitized solar cells, polymer-fullerene polymer solar cells, organometal halide perovskite solar cells, and finally some photocatalytic systems.

  7. ENERGY BUDGETS IN FREE-LIVING GREEN IGUANAS IN A SEASONAL ENVIRONMENT

    NARCIS (Netherlands)

    LICHTENBELT, WDV; WESSELINGH, RA; VOGEL, JT; ALBERS, KBM

    1993-01-01

    Using a variety of techniques we estimated energy expenditure and allocation of energy in free-living green iguanas (Iguana iguana) in a seasonal environment on Curacao, Netherlands Antilles. 1) Daily energy expenditure (DEE) was measured by means of the doubly labeled water (DLW) technique, using O

  8. Budget-in-brief, fiscal year 1998: Energy for today and tomorrow

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1997-09-01

    This document provides a brief overview of how the Energy Efficiency and Renewable Energy programs plan to improve: environmental quality, energy security, public health, and economic productivity. Substantial opportunities remain to improve the nation`s energy future without incurring high costs or imposing overly restrictive regulations. Current restructuring of electricity markets and international agreements on global climate change are focusing attention on some of these opportunities. With energy demand in countries such as China and India projected to grow exponentially in coming decades, US exports of clean energy technologies will be important for mitigating world environmental degradation and climate change--and for fostering strong US industries in sustainable energy products and services. Enabling developing countries to grow without the negative consequences of pollution is one of the most valuable forms of leadership the US can exercise in world affairs in the years ahead.

  9. Spacecraft Dynamic Characterization by Strain Energies Method

    Science.gov (United States)

    Bretagne, J.-M.; Fragnito, M.; Massier, S.

    2002-01-01

    In the last years the significant increase in satellite broadcasting demand, with the wide band communication dawn, has given a great impulse to the telecommunication satellite market. The big demand is translated from operators (such as SES/Astra, Eutelsat, Intelsat, Inmarsat, EuroSkyWay etc.) in an increase of orders of telecom satellite to the world industrials. The largest part of these telecom satellite orders consists of Geostationary platforms which grow more and more in mass (over 5 tons) due to an ever longer demanded lifetime (up to 20 years), and become more complex due to the need of implementing an ever larger number of repeaters, antenna reflectors and feeds, etc... In this frame, the mechanical design and verification of these large spacecraft become difficult and ambitious at the same time, driven by the dry mass limitation objective. By the Finite Element Method (FEM), and on the basis of the telecom satellite heritage of a world leader constructor such as Alcatel Space Industries it is nowadays possible to model these spacecraft in a realistic and confident way in order to identify the main global dynamic aspects such as mode shapes, mass participation and/or dynamic responses. But on the other hand, one of the main aims consists in identifying soon in a program the most critical aspects of the system behavior in the launch dynamic environment, such as possible dynamic coupling between the different subsystems and secondary structures of the spacecraft (large deployable reflectors, thrusters, etc.). To this aim a numerical method has been developed in the frame of the Alcatel SPACEBUS family program, using MSC/Nastran capabilities and it is presented in this paper. The method is based on Spacecraft sub-structuring and strain energy calculation. The method mainly consists of two steps : 1) subsystem modal strain energy ratio (with respect to the global strain energy); 2) subsystem strain energy calculation for each mode according to the base driven

  10. A hierarchy of energy- and flux-budget (EFB) turbulence closure models for stably stratified geophysical flows

    CERN Document Server

    Zilitinkevich, S S; Kleeorin, N; Rogachevskii, I; Esau, I

    2011-01-01

    In this paper we advance physical background of the EFB turbulence closure and present its comprehensive description. It is based on four budget equations for the second moments: turbulent kinetic and potential energies (TKE and TPE) and vertical turbulent fluxes of momentum and buoyancy; a new relaxation equation for the turbulent dissipation time-scale; and advanced concept of the inter-component exchange of TKE. The EFB closure is designed for stratified, rotating geophysical flows from neutral to very stable. In accordance to modern experimental evidence, it grants maintaining turbulence by the velocity shear at any gradient Richardson number Ri, and distinguishes between the two principally different regimes: "strong turbulence" at Ri 1 typical of the free atmosphere or deep ocean, where Pr_T asymptotically linearly increases with increasing Ri that implies strong suppressing of the heat transfer compared to momentum transfer. For use in different applications, the EFB turbulence closure is formulated a...

  11. Effects of water temperature and dietary carbohydrate levels on growth and energy budget of juvenile Litopenaeus vannamei

    Science.gov (United States)

    Wang, Xingqiang; Ma, Shen; Dong, Shuanglin

    2006-09-01

    A 3×3 factorial experiment was conducted to determine the effects of water temperature (22 °C, 27°C and 32°C) and dietary carbohydrate ( CBH) levels (15.47%, 29.15% and 41.00%) on growth, food consumption, feed efficiency, apparent digestibility coefficient and energy budget of juvenile Litopenaeus vannamei. The results showed that, at each dietary CBH level, specific growth rate, food consumption and apparent digestibility coefficient generally increased, while feed efficiency decreased with increasing water temperatures. Specific growth rate and food consumption were the highest in the shrimps fed with diet of 29.15% CBH, closely followed by those with 15.47% CBH, and those with 41.00% CBH had the lowest value.

  12. Effects of water temperature and dietary carbohydrate levels on growth and energy budget of juvenile Litopenaeus vannamei

    Institute of Scientific and Technical Information of China (English)

    WANG Xingqiang; MA Shen; DONG Shuanglin

    2006-01-01

    A 3×3 factorial experiment was conducted to determine the effects of water temperature (22 ℃, 27℃ and 32℃) and dietary carbohydrate (CBH) levels (15.47%, 29.15% and 41.00%) on growth, food consumption, feed efficiency, apparent digestibility coefficient and energy budget of juvenile Litopenaeus vannamei. The results showed that, at each dietary CBH level, specific growth rate, food consumption and apparent digestibility coefficient generally increased, while feed efficiency decreased with increasing water temperatures. Specific growth rate and food consumption were the highest in the shrimps fed with diet of 29.15% CBH, closely followed by those with 15.47% CBH, and those with 41.00% CBH had the lowest value.

  13. Federal Energy Management Program FY 2017 Budget At-A-Glance

    Energy Technology Data Exchange (ETDEWEB)

    None

    2016-03-01

    With more than 350,000 buildings and 600,000 vehicles, the federal government is America’s largest single energy consumer. There is a tremendous opportunity and responsibility to lead by example in cutting energy waste and advancing America’s clean energy future. The progress the federal government has made to date, through public-private partnerships and successful approaches, should be leveraged to show leadership to the nation and continue to make significant contributions to our national energy and environmental goals.

  14. Solar Energy Technologies Office FY 2017 Budget At-A-Glance

    Energy Technology Data Exchange (ETDEWEB)

    None, None

    2016-03-01

    The Solar Energy Technologies Office supports the SunShot Initiative goal to make solar energy technologies cost competitive with conventional energy sources by 2020. Reducing the total installed cost for utility-scale solar electricity by approximately 75% (2010 baseline) to roughly $0.06 per kWh without subsidies will enable rapid, large-scale adoption of solar electricity across the United States. This investment will help re-establish American technological and market leadership in solar energy, reduce environmental impacts of electricity generation, and strengthen U.S. economic competitiveness.

  15. 10 CFR 434.602 - Determination of the annual energy budget.

    Science.gov (United States)

    2010-01-01

    ... fuel (the fuel selections having been made by a life cycle cost analysis in determining the proposed... factors given in Table 602.2, Fuel Conversion Factors for Computing Design Annual Energy Uses. In lieu of... for the combinations of energy source(s) that may be considered in a set of project designs, such as...

  16. 10 CFR 434.506 - Use of the reference building to determine the energy cost budget.

    Science.gov (United States)

    2010-01-01

    ... be oriented in the same manner for the Reference Building as in the Proposed Design. The form, gross... Proposed Design. All other characteristics, such as lighting, envelope and HVAC systems and equipment... 10 Energy 3 2010-01-01 2010-01-01 false Use of the reference building to determine the energy...

  17. Putting Desire on a Budget: Dopamine and Energy Expenditure, Reconciling Reward and Resources

    Directory of Open Access Journals (Sweden)

    Jeff A Beeler

    2012-07-01

    Full Text Available Accumulating evidence indicates integration of dopamine function with metabolic signals, highlighting a potential role for dopamine in energy balance, frequently construed as modulating reward in response to homeostatic state. Though its precise role remains controversial, the reward perspective of dopamine has dominated investigation of motivational disorders, including obesity. In the hypothesis outlined here, we suggest instead that the primary role of dopamine in behavior is to modulate activity to adapt behavioral energy expenditure to the prevailing environmental energy conditions, with the role of dopamine in reward and motivated behaviors derived from its primary role in energy balance. Dopamine has long been known to modulate activity, exemplified by psychostimulants that act via dopamine. More recently, there has been nascent investigation into the role of dopamine in modulating voluntary activity, with some investigators suggesting that dopamine may serve as a final common pathway that couples energy sensing to regulated voluntary energy expenditure. We suggest that interposed between input from both the internal and external world, dopamine modulates behavioral energy expenditure along two axes: a conserve-expend axis that regulates generalized activity and an explore-exploit axes that regulates the degree to which reward value biases the distribution of activity. In this view, increased dopamine does not promote consumption of tasty food. Instead increased dopamine promotes energy expenditure and exploration while decreased dopamine favors energy conservation and exploitation. This hypothesis provides a mechanistic interpretation to an apparent paradox: the well-established role of dopamine in food seeking and the findings that low dopaminergic functions are associated with obesity. Our hypothesis provides an alternative perspective on the role of dopamine in obesity and reinterprets the ‘reward deficiency hypothesis’ as a

  18. Hexcrete Tower for Harvesting Wind Energy at Taller Hub Heights - Budget Period 2

    Energy Technology Data Exchange (ETDEWEB)

    Sritharan, Sri [Iowa State Univ., Ames, IA (United States)

    2017-05-01

    Interest in designing taller towers for wind energy production in the United States (U.S.) has been steadily growing. In May 2015, it was revealed that taller towers will make wind energy production a reality in all 50 states, including some states that have nearly zero renewables in their energy portfolio. Facilitating wind energy production feasibility in all 50 states will no doubt contribute to increasing the electricity produced by wind from 4.5% in 2013 to a targeted scenario of 35% by 2050 in the Wind Vision report. This project focuses on the Hexcrete tower concept developed for tall towers using High Strength Concrete (HSC) and/or Ultra-High Performance Concrete (UHPC). Among other benefits, the Hexcrete concept overcomes transportation and logistical challenges, thus facilitating construction of towers with hub heights of 100-m (328-ft) and higher. The goal of this project is to facilitate widespread deployment of Hexcrete towers for harvesting wind energy at 120 to 140-m (394 to 459-ft) hub heights and reduce the Levelized Cost of Energy (LCOE) of wind energy production in the U.S. The technical scope of the project includes detailed design and optimization of at least three wind turbine towers using the Hexcrete concept together with experimental validation and LCOE analyses and development of a commercialization plan.

  19. Effective Free Energy for Individual Dynamics

    CERN Document Server

    Grauwin, Sebastian; Bertin, Eric; Jensen, Pablo; 10.1142/S0219525911003128

    2011-01-01

    Physics and economics are two disciplines that share the common challenge of linking microscopic and macroscopic behaviors. However, while physics is based on collective dynamics, economics is based on individual choices. This conceptual difference is one of the main obstacles one has to overcome in order to characterize analytically economic models. In this paper, we build both on statistical mechanics and the game theory notion of Potential Function to introduce a rigorous generalization of the physicist's free energy, which includes individual dynamics. Our approach paves the way to analytical treatments of a wide range of socio-economic models and might bring new insights into them. As first examples, we derive solutions for a congestion model and a residential segregation model.

  20. The global infrared energy budget of the thermosphere from 1947 to 2016 and implications for solar variability

    Science.gov (United States)

    Mlynczak, Martin G.; Hunt, Linda A.; Russell, James M.; Marshall, B. Thomas; Mertens, Christopher J.; Thompson, R. Earl

    2016-12-01

    We present an empirical model of the global infrared energy budget of the thermosphere over the past 70 years. The F10.7, Ap, and Dst indices are used in linear regression fits to the 14.5 year time series of radiative cooling by carbon dioxide and nitric oxide measured by the Sounding of the Atmosphere using Broadband Emission Radiometry (SABER) instrument on the TIMED satellite. Databases of these indices are used to develop the radiative cooling time series from 1947. No consistent relation between the occurrence of peak sunspot number and peak infrared cooling is found over the past six solar cycles. The total infrared energy radiated by the thermosphere, integrated over a solar cycle, is nearly constant over five complete solar cycles studied. This is a direct consequence of the geoeffective solar energy also being nearly constant over the same intervals. These results provide a new metric for assessing the terrestrial context of the long-term record of solar-related indices.

  1. Energy Transferring Dynamic Equalization for Battery Packs

    Institute of Scientific and Technical Information of China (English)

    2005-01-01

    The equivalent circuit model of battery and the analytic model of series battery uniformities are setup. The analysis shows that it is the key to maintain small voltage difference between cells in order to improve uniformities. Therefore a new technique combining low voltage difference, big current charging and bi-directional charge equalizer system is put forward and designed. The test shows that the energy transferring dynamic equalization system betters the series battery uniformities and protection during charging and discharging, improves the battery performance and extends the use life of series battery.

  2. Fission dynamics at low excitation energy. 2

    CERN Document Server

    Aritomo, Y; Ivanyuk, F A

    2014-01-01

    The mass asymmetry in the fission of U-236 at low excitation energy is clarified by the analysis of the trajectories obtained by solving the Langevin equations for the shape degrees of freedom. It is demonstrated that the position of the peaks in the mass distribution of fission fragments is determined mainly by the saddle point configuration originating from the shell correction energy. The width of the peaks, on the other hand, results from the shape fluctuations close to the scission point caused by the random force in the Langevin equation. We have found out that the fluctuations between elongated and compact shapes are essential for the fission process. According to our results the fission does not occur with continuous stretching in the prolate direction, similarly to that observed in starch syrup, but is accompanied by the fluctuations between elongated and compact shapes. This picture presents a new viewpoint of fission dynamics and the splitting mechanism.

  3. Fission dynamics at low excitation energy

    CERN Document Server

    Aritomo, Y

    2013-01-01

    The origin of mass asymmetry in the fission of uranium at a low excitation energy is clarified by a trajectory analysis of the Langevin equation. The positions of the peaks in the mass distribution of fission fragments are mainly determined by fission saddle points originating from the shell correction energy. The widths of the peaks, on the other hand, result from a shape fluctuation around the scission point caused by the random force in the Langevin equation. We found that a random vibration in the oblate direction of fissioning fragments is essential for the fission process. According to this picture, fission does not occur with continuous stretching in the prolate direction, similarly to that observed in starch syrup. This is expected to lead to a new viewpoint of fission dynamics and the splitting mechanism.

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

    Indian Academy of Sciences (India)

    G S Bhat; S C Arunchandra

    2008-12-01

    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 based on the bulk method using measurements made at two levels on a micrometeorological tower of 10 m height. The bulk flux formulation is verified by comparing its fluxes with direct fluxes using sonic anemometer data sampled at 10 Hz.Soil temperature is measured at 4 depths. Data have been continuously collected for over 6 months covering pre-monsoon and monsoon periods during the year 2006. The study first addresses the issue of getting the fluxes accurately.It is shown that water vapour measurements are the most crucial. A bias of 0.25% in relative humidity,which is well above the normal accuracy assumed by the manufacturers but achievable in the field using a combination of laboratory calibration and field intercomparisons, results in about 20 W m−2 change in the latent heat flux on the seasonal time scale. When seen on the seasonal time scale,the net longwave radiation is the largest energy loss term at the experimental site. The seasonal variation in the energy sink term is small compared to that in the energy source term.

  5. Energy Budget of Forming Clumps in Numerical Simulations of Collapsing Clouds

    Science.gov (United States)

    Camacho, Vianey; Vázquez-Semadeni, Enrique; Ballesteros-Paredes, Javier; Gómez, Gilberto C.; Fall, S. Michael; Mata-Chávez, M. Dolores

    2016-12-01

    We analyze the physical properties and energy balance of density enhancements in two SPH simulations of the formation, evolution, and collapse of giant molecular clouds. In the simulations, no feedback is included, so all motions are due either to the initial decaying turbulence or to gravitational contraction. We define clumps as connected regions above a series of density thresholds. The resulting full set of clumps follows the generalized energy equipartition relation, {σ }v/{R}1/2\\propto {{{Σ }}}1/2, where {σ }v is the velocity dispersion, R is the “radius,” and Σ is the column density. We interpret this as a natural consequence of gravitational contraction at all scales rather than virial equilibrium. Nevertheless, clumps with low Σ tend to show a large scatter around equipartition. In more than half of the cases, this scatter is dominated by external turbulent compressions that assemble the clumps rather than by small-scale random motions that would disperse them. The other half does actually disperse. Moreover, clump sub-samples selected by means of different criteria exhibit different scalings. Sub-samples with narrow Σ ranges follow Larson-like relations, although characterized by their respective values of Σ. Finally, we find that (i) clumps lying in filaments tend to appear sub-virial, (ii) high-density cores (n≥slant {10}5 cm3) that exhibit moderate kinetic energy excesses often contain sink (“stellar”) particles and the excess disappears when the stellar mass is taken into account in the energy balance, and (iii) cores with kinetic energy excess but no stellar particles are truly in a state of dispersal.

  6. FY 1997 congressional budget request: Budget highlights

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1996-03-01

    This is an overview of the 1997 budget request for the US DOE. The topics of the overview include a policy overview, the budget by business line, business lines by organization, crosswalk from business line to appropriation, summary by appropriation, energy supply research and development, uranium supply and enrichment activities, uranium enrichment decontamination and decommissioning fund, general science and research, weapons activities, defense environmental restoration and waste management, defense nuclear waste disposal, departmental administration, Office of the Inspector General, power marketing administrations, Federal Energy Regulatory commission, nuclear waste disposal fund, fossil energy research and development, naval petroleum and oil shale reserves, energy conservation, economic regulation, strategic petroleum reserve, energy information administration, clean coal technology and a Department of Energy Field Facilities map.

  7. DYNAMIC FREE ENERGY HYSTERESIS MODEL IN MAGNETOSTRICTIVE ACTUATORS

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    A dynamic free energy hysteresis model in magnetostrictive actuators is presented. It is the free energy hysteresis model coupled to an ordinary different equation in an unusual way. According to its special structure, numerical implementation method of the dynamic model is provided. The resistor parameter in the dynamic model changes according to different frequency ranges. This makes numerical implementation results reasonable in the discussed operating frequency range. The validity of the dynamic free energy model is illustrated by comparison with experimental data.

  8. Suppressing breakers with polar oil films: Using an epic sea rescue to model wave energy budgets

    Science.gov (United States)

    Cox, Charles S.; Zhang, Xin; Duda, Timothy F.

    2017-02-01

    Oil has been used to still stormy seas for centuries, but the mechanisms are poorly understood. Here we examine the processes by using quantitative information from a remarkable 1883 sea rescue where oil was used to reduce large breakers during a storm. Modeling of the oil film's extent and waves under the film suggests that large breakers were suppressed by a reduction of wind energy input. Modification of surface roughness by the film is hypothesized to alter the wind profile above the sea and the energy flow. The results are central to understanding air-sea momentum exchange, including its role in such processes as cyclone growth and storm surge, although they address only one aspect of the complex problem of wind interaction with the ocean surface.

  9. Trends in Benthic macroinvertebrate community Biomass and Energy Budgets in Lake Sevan, 1928-2004

    Science.gov (United States)

    Stapanian, Martin A.; Jenderedjian, K.; Hakobyan, S.

    2012-01-01

    Water levels of Lake Sevan (Armenia) were artificially lowered by nearly 20 m between 1949 and 1997. Lowered water levels, combined with increased eutrophication, were associated with seasonally anoxic conditions (lasting 1–4 months) near the bottom of the profundal zone each year during 1976–2004. In addition, the extents of the macrophyte zone and of certain substrate types were severely reduced following drawdown. Maximal depth of occurrence decreased by 2–44 m for at least for 50 species of benthic macroinvertebrates between 1982 and 2004 compared to 1937–1961. Species richness of benthic macroinvertebrates declined from 25 to three species at depths where seasonal anoxia occurred. Total biomass increased by a factor of 10 from the period 1928–1948 to 1976–1979 then declined by a factor of 3 to 4 between 1987 and 2004. Energy flow through detritivores was more than tripled during 1976–2004 compared to 1928–1971, a result of increased plankton primary production. In contrast, energy flow through herbivorous benthic macroinvertebrates decreased by a factor of nearly 5, due to reduced areal coverage of macrophytes. Energy flow through filter feeders did not change over the time period examined, but energy flow through the entire zoobenthos community was nearly tripled. The biomasses of Oligochaeta, Chironomidae, and total zoobenthos showed a delayed response to changes in primary production of 7–9, 2, and 2–4 years, respectively. These patterns may provide a basis to predict results of restoration efforts based on the abundance of the zoobenthos in future years as the level of the lake is restored and water quality improves.

  10. The energy budget of GRBs based on updated prompt \\& afterglow observations

    CERN Document Server

    Wygoda, Nahliel; Mandich, Marc-Adrien; Waxman, Eli

    2015-01-01

    We compare the isotropic equivalent 15-2000 keV gamma-ray energy, E_gamma, emitted by a sample of 91 swift Gamma-Ray Bursts (GRBs) with known redshifts, with the isotropic equivalent fireball energy, E_fb, as estimated within the fireball model framework from X-ray afterglow observations of these bursts. The uncertainty in E_gamma, which spans the range of ~10^51 erg to ~10^53.5 erg, is approximately 25% on average, due mainly to the extrapolation from the BAT detector band to the 15-2000 keV band. The uncertainty in E_fb is approximately a factor of 2, due mainly to the X-ray measurements' scatter. We find E_gamma and E_fb to be tightly correlated. The average(std) of {\\eta}^11hr_gamma is approximately log_10(E_gamma/(3{\\epsilon} _eE^11hr_fb)) are -0.34(0.60), and the upper limit on the intrinsic spread of {\\eta}_gamma is approximately 0.5 ({\\epsilon}_e is the fraction of shocked plasma energy carried by electrons and E^x hr_fb is inferred from the X-ray flux at x hours). We also find that E_fb inferred from...

  11. Dynamic management of integrated residential energy systems

    Science.gov (United States)

    Muratori, Matteo

    dissertation presents a bottom-up highly resolved model of a generic residential energy eco-system in the United States. The model is able to capture the entire energy footprint of an individual household, to include all appliances, space conditioning systems, in-home charging of plug-in electric vehicles, and any other energy needs, viewing residential and transportation energy needs as an integrated continuum. The residential energy eco-system model is based on a novel bottom-up approach that quantifies consumer energy use behavior. The incorporation of stochastic consumer behaviors allows capturing the electricity consumption of each residential specific end-use, providing an accurate estimation of the actual amount of available controllable resources, and for a better understanding of the potential of residential demand response programs. A dynamic energy management framework is then proposed to manage electricity consumption inside each residential energy eco-system. Objective of the dynamic energy management framework is to optimize the scheduling of all the controllable appliances and in-home charging of plug-in electric vehicles to minimize cost. Such an automated energy management framework is used to simulate residential demand response programs, and evaluate their impact on the electric power infrastructure. For instance, time-varying electricity pricing might lead to synchronization of the individual residential demands, creating pronounced rebound peaks in the aggregate demand that are higher and steeper than the original demand peaks that the time-varying electricity pricing structure intended to eliminate. The modeling tools developed in this study can serve as a virtual laboratory for investigating fundamental economic and policy-related questions regarding the interplay of individual consumers with energy use. The models developed allow for evaluating the impact of different energy policies, technology adoption, and electricity price structures on the total

  12. Irreversible energy flow in forced Vlasov dynamics

    KAUST Repository

    Plunk, Gabriel G.

    2014-10-01

    © EDP Sciences, Società Italiana di Fisica, Springer-Verlag. The recent paper of Plunk [G.G. Plunk, Phys. Plasmas 20, 032304 (2013)] considered the forced linear Vlasov equation as a model for the quasi-steady state of a single stable plasma wavenumber interacting with a bath of turbulent fluctuations. This approach gives some insight into possible energy flows without solving for nonlinear dynamics. The central result of the present work is that the forced linear Vlasov equation exhibits asymptotically zero (irreversible) dissipation to all orders under a detuning of the forcing frequency and the characteristic frequency associated with particle streaming. We first prove this by direct calculation, tracking energy flow in terms of certain exact conservation laws of the linear (collisionless) Vlasov equation. Then we analyze the steady-state solutions in detail using a weakly collisional Hermite-moment formulation, and compare with numerical solution. This leads to a detailed description of the Hermite energy spectrum, and a proof of no dissipation at all orders, complementing the collisionless Vlasov result.

  13. Passivhaus: indoor comfort and energy dynamic analysis.

    Science.gov (United States)

    Guida, Antonella; Pagliuca, Antonello; Cardinale, Nicola; Rospi, Gianluca

    2013-04-01

    The research aims to verify the energy performance as well as the indoor comfort of an energy class A+ building, built so that the sum of the heat passive contributions of solar radiation, transmitted through the windows, and the heat generated inside the building, are adeguate to compensate for the envelope loss during the cold season. The building, located in Emilia Romagna (Italy), was built using a wooden structure, an envelope realized using a pinewood sandwich panels (transmittance U = 0.250 W/m2K) and, inside, a wool flax insulation layer and thermal window frame with low-emissivity glass (U = 0524 W/m2K). The building design and construction process has followed the guidelines set by "CasaClima". The building has been modeled in the code of dynamic calculation "Energy Plus" by the Design Builder application and divided it into homogenous thermal zones, characterized by winter indoor temperature set at 20 ° (+ / - 1 °) and summer indoor temperature set at 26 ° (+ / - 1 °). It has modeled: the envelope, as described above, the "free" heat contributions, the air conditioning system, the Mechanical Ventilation system as well as home automation solutions. The air conditioning system is an heat pump, able to guarantee an optimization of energy consumption (in fact, it uses the "free" heat offered by the external environment for conditioning indoor environment). As regards the air recirculation system, it has been used a mechanical ventilation system with internal heat cross-flow exchanger, with an efficiency equal to 50%. The domotic solutions, instead, regard a system for the control of windows external screening using reeds, adjustable as a function of incident solar radiation and a lighting management system adjusted automatically using a dimmer. A so realized building meets the requirement imposed from Italian standard UNI/TS 11300 1, UNI/TS 11300 2 and UNI/TS 11300 3. The analysis was performed according to two different configurations: in "spontaneous

  14. Energy budget of forming clumps in numerical simulations of collapsing clouds

    CERN Document Server

    Camacho, Vianey; Ballesteros-Paredes, Javier; Gómez, Gilberto C; Fall, S Michael; Mata-Chávez, M Dolores

    2016-01-01

    We analyze the physical properties and energy balance of density enhancements in two SPH simulations of the formation, evolution, and collapse of giant molecular clouds. In the simulations, no feedback is included, and so all motions are due either to the initial, decaying turbulence, or to gravitational contraction. We define the clumps as connected regions above a series of density thresholds.The resulting full set of clumps follow the generalized energy-equipartition relation $\\sigma_{v}/R^{1/2} \\propto \\Sigma^{1/2}$, where $\\sigma_{v}$ is the velocity dispersion, $R$ is the "radius", and $\\Sigma$ is the column density. We interpret this as a natural consequence of gravitational contraction at all scales, rather than virial equilibrium. However, clumps sub-samples selected by means of different criteria exhibit different scalings with size. Clumps selected by column density ranges follow Larson-like relations and clumps defined at lower density thresholds tend to show a larger scatter around equipartition....

  15. Simulated Effects of Land Cover Conversion on the Surface Energy Budget in the Southwest of China

    Directory of Open Access Journals (Sweden)

    Jiangbo Gao

    2014-03-01

    Full Text Available In this paper, the coupled WRF/SSiB model, accompanied by a Karst Rocky Desertification (KRD map of the Guizhou Karst Plateau (GKP of China, was applied to detect how the changed vegetation and soil characteristics over the GKP modify the energy balance at the land surface. The results indicated that land degradation led to reduced net radiation by inducing more upward shortwave and longwave radiation, which were associated with increasing surface albedo and temperature, respectively. The KRD also resulted in changed surface energy partitioning into sensible and latent heat fluxes. The latent heat flux at land surface was reduced substantially due to the higher surface albedo and stomatal resistance, the lower Leaf Area Index (LAI and roughness length in the degradation experiment, while the sensible heat flux increased, mainly because of the higher surface temperature. Furthermore, the moisture flux convergence was reduced, owing to the lower atmospheric heating and the relative subsidence. However, compared with the reduced evaporation, the decrease in moisture flux convergence contributed much less to the reduced precipitation. Precipitation strongly affects soil moisture, vegetation growth and phenology, and thus evaporation and convective latent heating, so when precipitation was changed, a feedback loop was created.

  16. Definition of Total Energy budget equation in terms of moist-air Enthalpy surface flux

    CERN Document Server

    Marquet, Pascal

    2015-01-01

    Uncertainty exists concerning the proper formulation of surface heat fluxes, namely the sum of "sensible" and "latent" heat fluxes, and in fact concerning these two fluxes if they are considered as separate fluxes. In fact, eddy flux of moist-air energy must be defined as the eddy transfer of moist-air specific enthalpy ($\\overline{w' h'}$), where the specific enthalpy ($h$) is equal to the internal energy of moist air plus the pressure divided by the density (namely $h = e_{\\rm int} + p/\\rho$). The fundamental issue is to compute this local (specific) moist-air enthalpy ($h$), and in particular to determine absolute reference value of enthalpies for dry air and water vapour $(h_d)_{\\rm ref}$ and $(h_v)_{\\rm ref}$. New results shown in Marquet (QJRMS 2015, arXiv:1401.3125) are based on the Third-law of Thermodynamics and can allow these computations. In this note, this approach is taken to show that Third-law based values of moist-air enthalpy fluxes is the sum of two terms. These two terms are similar to wha...

  17. An energy budget for the subtidal bivalve Modiolus barbatus (Mollusca) at different temperatures.

    Science.gov (United States)

    Ezgeta-Balić, D; Rinaldi, A; Peharda, M; Prusina, I; Montalto, V; Niceta, N; Sarà, G

    2011-02-01

    Clearance rates, respiration rates and food absorption efficiencies of the commercially interesting subtidal bivalve Modiolus barbatus were measured at different temperatures under laboratory conditions and scope for growth calculated. Clearance rates were highest at temperatures from 20 °C to 28 °C, whereas respiration rate was maximal at 9 °C and minimal at 26 °C. Highest mean values of absorbed energy occurred at 20 °C and 26 °C. Scope for growth trend had negative values at 9 °C, 15 °C and 28 °C and positive values at temperatures 20 °C and 26 °C. The profitable thermal window for M. barbatus to have energy sufficient for growth and reproduction corresponded to <5 months per year. Seawater temperature increases will potentially impact the eco-physiological responses of subtidal M. barbatus causing life history traits to change with important repercussions for subtidal biodiversity in the Mediterranean. © 2010 Elsevier Ltd. All rights reserved.

  18. Dynamic energy-demand models. A comparison

    Energy Technology Data Exchange (ETDEWEB)

    Yi, Feng [Department of Economics, Goeteborg University, Gothenburg (Sweden)

    2000-04-01

    This paper compares two second-generation dynamic energy demand models, a translog (TL) and a general Leontief (GL), in the study of price elasticities and factor substitutions of nine Swedish manufacturing industries: food, textiles, wood, paper, printing, chemicals, non-metallic minerals, base metals and machinery. Several model specifications are tested with likelihood ratio test. There is a disagreement on short-run adjustments; the TL model accepts putty-putty production technology of immediate adjustments, implying equal short- and long-run price elasticities of factors, while the GL model rejects immediate adjustments, giving out short-run elasticities quite different from the long-run. The two models also disagree in substitutability in many cases. 21 refs.

  19. Baryogenesis, neutrino masses, and dynamical dark energy

    Energy Technology Data Exchange (ETDEWEB)

    Eisele, M.T.

    2007-10-09

    This thesis considers several models that connect different areas of particle physics and cosmology. Our first discussion in this context concerns a baryogenesis scenario, in which the baryon asymmetry of our universe is created through the dynamics of a dark energy field, thereby illustrating that these two topics might be related. Subsequently, several neutrino mass models are analyzed, which make use of an extra-dimensional setting to overcome certain problems of their fourdimensional counterparts. The central discussion of this thesis concerns a leptogenesis model with many standard model singlets. Amongst other things, we show that the presence of these states can lower the standard bound for the necessary reheating temperature of the universe by at least one and a half orders of magnitude. To further motivate this approach, we also discuss an explicit, extradimensional leptogenesis scenario that naturally yields many of the ingredients required in this context. (orig.)

  20. The energy budget of stellar magnetic fields: comparing non-potential simulations and observations

    CERN Document Server

    Lehmann, L T; Vidotto, A A; Mackay, D H; See, V; Donati, J -F; Folsom, C P; Jeffers, S V; Marsden, S C; Morin, J; Petit, P

    2016-01-01

    The magnetic geometry of the surface magnetic fields of more than 55 cool stars have now been mapped using spectropolarimetry. In order to better understand these observations, we compare the magnetic field topology at different surface scale sizes of observed and simulated cool stars. For ease of comparison between the high-resolution non-potential magnetofrictional simulations and the relatively low-resolution observations, we filter out the small-scale field in the simulations using a spherical harmonics decomposition. We show that the large-scale field topologies of the solar-based simulations produce values of poloidal/toroidal fields and fractions of energy in axisymmetric modes that are similar to the observations. These global non-potential evolution model simulations capture key magnetic features of the observed solar-like stars through the processes of surface flux transport and magnetic flux emergence. They do not, however, reproduce the magnetic field of M-dwarfs or stars with dominantly toroidal ...

  1. Wind-farms in shallow conventionally neutral boundary layers: effects of transition and gravity waves on energy budget

    Science.gov (United States)

    Meyers, Johan; Allaerts, Dries

    2016-11-01

    Conventionally neutral boundary layers (CNBL) often arise in offshore conditions. In these situations the neutral boundary layer is capped by a strong inversion layer and a stably stratified free atmosphere aloft. We use large-eddy simulations to investigate the interaction between a CNBL and a large wind farm. Following the approach of Allaerts & Meyers (2015), a set of equilibrium CNBLs are produced in a precursor simulation, with a height of approx. 300, 500, and 1000m, respectively. These are used at the inlet of a large wind-farm with a fetch of 15 km, and 20 rows of turbines. We find that above the farm, an internal boundary layer (IBL) develops. For the two lower CNBL cases, the IBL growth is stopped by the overlying capping inversion. Moreover, the upward displacement of the CNBL excites gravity waves in the inversion layer and the free atmosphere above. For the lower CNBL cases, these waves induce significant pressure gradients in the farm. A detailed energy budget analysis of the CNBL is further presented. The authors acknowledge support from the European Research Council (FP7-Ideas, Grant No. 306471).

  2. Single-wave-number representation of nonlinear energy spectrum in elastic-wave turbulence of the Föppl-von Kármán equation: energy decomposition analysis and energy budget.

    Science.gov (United States)

    Yokoyama, Naoto; Takaoka, Masanori

    2014-12-01

    A single-wave-number representation of a nonlinear energy spectrum, i.e., a stretching-energy spectrum, is found in elastic-wave turbulence governed by the Föppl-von Kármán (FvK) equation. The representation enables energy decomposition analysis in the wave-number space and analytical expressions of detailed energy budgets in the nonlinear interactions. We numerically solved the FvK equation and observed the following facts. Kinetic energy and bending energy are comparable with each other at large wave numbers as the weak turbulence theory suggests. On the other hand, stretching energy is larger than the bending energy at small wave numbers, i.e., the nonlinearity is relatively strong. The strong correlation between a mode a(k) and its companion mode a(-k) is observed at the small wave numbers. The energy is input into the wave field through stretching-energy transfer at the small wave numbers, and dissipated through the quartic part of kinetic-energy transfer at the large wave numbers. Total-energy flux consistent with energy conservation is calculated directly by using the analytical expression of the total-energy transfer, and the forward energy cascade is observed clearly.

  3. Simulated Impacts of a change in the AMOC on the global Climate; an Energy Budget Perspective.

    Science.gov (United States)

    Codron, F.; L'Héveder, B.

    2015-12-01

    This study explores the impact of anomalous northward oceanic heat transport bythe AMOC on the global climate. We first use the LMDZ5 AGCM of theLaboratoire de Météorologie Dynamique coupled to a slab ocean, with realisticzonal asymmetries and seasonal cycle. Two anomalous surface heatingsreproducing the impact of an idealized AMOC strenghtening are imposed: (a)uniform heating over the North Atlantic basin, and (b) concentrated heating inthe Gulf Stream region; in both cases a compensating uniform cooling in the SouthernOcean is applied. The magnitude of the heating, and of the implied northwardinter-hemispheric heat transport, are within the range of current naturalvariability. Both simulations show global effects, which can be interpreted as acompensation by the atmosphere of the anomalous oceanic heat transport: theIntertropical Convergence Zone (ITCZ) shifts north toward the heatinganomalies. This shift is accompanied by a northward shift of the jets and stormtracks in both hemispheres, consistent with anomalous soutward heat transportby transient eddies in the subtropics. In the extra-tropics, the clear-sky radiative response tends to damp theprescribed anomalies, while the cloud response acts as a large positivefeedback on the oceanic forcing, mainly due to the low-cloud induced shortwaveanomalies. In the tropics, the clear-sky response is dominated instead byhumidity changes and reinforces the ITCZ movements. We then use a fully coupled GCM in glacial conditions, in which a freshwaterflux ("hosing") is added in the North Atlantic to weaken the AMOC. We stillobserve a strong compensation between the ocean and atmosphere heat transports,as well as a southward shift of the ITCZ, and of the Southern Hemisphere jetand storm tracks. There is however no warming of the Southern mid and highlatitudes. In addition to the compensation mechanisms of the slab ocean settings, newfeedbacks on the meridional energy transports by the oceanic circulationappear. The Southern

  4. System Budgets

    DEFF Research Database (Denmark)

    Jeppesen, Palle

    1996-01-01

    The lecture note is aimed at introducing system budgets for optical communication systems. It treats optical fiber communication systems (six generations), system design, bandwidth effects, other system impairments and optical amplifiers.......The lecture note is aimed at introducing system budgets for optical communication systems. It treats optical fiber communication systems (six generations), system design, bandwidth effects, other system impairments and optical amplifiers....

  5. Budget timetable

    Science.gov (United States)

    This is a timetable for congressional action under the Balanced Budget and Emergency Deficit Control Act of 1985 (Gramm-Rudman-Hollings). These deadlines apply to fiscal years (FY) 1987-1991. The Congress missed a number of these deadlines last year. The deficit reduction measures in Gramm-Rudman-Hollings would lead to a balanced budget in 1991.

  6. Seasonal adjustment of energy budget in a large wild mammal, the Przewalski horse (Equus ferus przewalskii) II. Energy expenditure.

    Science.gov (United States)

    Arnold, Walter; Ruf, Thomas; Kuntz, Regina

    2006-11-01

    Many large mammals show pronounced seasonal fluctuations of metabolic rate (MR). It has been argued, based on studies in ruminants, that this variation merely results from different levels of locomotor activity (LA), and heat increment of feeding (HI). However, a recent study in red deer (Cervus elaphus) identified a previously unknown mechanism in ungulates--nocturnal hypometabolism--that contributed significantly to reduced energy expenditure, mainly during late winter. The relative contribution of these different mechanisms to seasonal adjustments of MR is still unknown, however. Therefore, in the study presented here we quantified for the first time the independent contribution of thermoregulation, LA and HI to heart rate (f(H)) as a measure of MR in a free-roaming large ungulate, the Przewalski horse or Takhi (Equus ferus przewalskii Poljakow). f(H) varied periodically throughout the year with a twofold increase from a mean of 44 beats min(-1) during December and January to a spring peak of 89 beats min(-1) at the beginning of May. LA increased from 23% per day during December and January to a mean level of 53% per day during May, and declined again thereafter. Daily mean subcutaneous body temperature (T(s)) declined continuously during winter and reached a nadir at the beginning of April (annual range was 5.8 degrees C), well after the annual low of air temperature and LA. Lower T(s) during winter contributed considerably to the reduction in f(H). In addition to thermoregulation, f(H) was affected by reproduction, LA, HI and unexplained seasonal variation, presumably reflecting to some degree changes in organ mass. The observed phase relations of seasonal changes indicate that energy expenditure was not a consequence of energy uptake but is under endogenous control, preparing the organism well in advance of seasonal energetic demands.

  7. Amazon River dissolved load: temporal dynamics and annual budget from the Andes to the ocean.

    Science.gov (United States)

    Moquet, Jean-Sébastien; Guyot, Jean-Loup; Crave, Alain; Viers, Jérôme; Filizola, Naziano; Martinez, Jean-Michel; Oliveira, Tereza Cristina; Sánchez, Liz Stefanny Hidalgo; Lagane, Christelle; Casimiro, Waldo Sven Lavado; Noriega, Luis; Pombosa, Rodrigo

    2016-06-01

    The aim of the present study is to estimate the export fluxes of major dissolved species at the scale of the Amazon basin, to identify the main parameters controlling their spatial distribution and to identify the role of discharge variability in the variability of the total dissolved solid (TDS) flux through the hydrological cycle. Data are compiled from the monthly hydrochemistry and daily discharge database of the "Programa Climatologico y Hidrologico de la Cuenca Amazonica de Bolivia" (PHICAB) and the HYBAM observatories from 34 stations distributed over the Amazon basin (for the 1983-1992 and 2000-2012 periods, respectively). This paper consists of a first global observation of the fluxes and temporal dynamics of each geomorphological domain of the Amazon basin. Based on mean interannual monthly flux calculations, we estimated that the Amazon basin delivered approximately 272 × 10(6) t year(-1) (263-278) of TDS during the 2003-2012 period, which represents approximately 7 % of the continental inputs to the oceans. This flux is mainly made up by HCO3, Ca and SiO2, reflecting the preferential contributions of carbonate and silicate chemical weathering to the Amazon River Basin. The main tributaries contributing to the TDS flux are the Marañon and Ucayali Rivers (approximately 50 % of the TDS production over 14 % of the Amazon basin area) due to the weathering of carbonates and evaporites drained by their Andean tributaries. An Andes-sedimentary area-shield TDS flux (and specific flux) gradient is observed throughout the basin and is first explained by the TDS concentration contrast between these domains, rather than variability in runoff. This observation highlights that, under tropical context, the weathering flux repartition is primarily controlled by the geomorphological/geological setting and confirms that sedimentary areas are currently active in terms of the production of dissolved load. The log relationships of concentration vs discharge have

  8. The surface energy budget and interannual variation of the annual total evaporation over a highland lake in Southwest China

    Science.gov (United States)

    Feng, Jian Wu; Liu, Hui Zhi; Sun, Ji Hua; Wang, Lei

    2016-10-01

    The turbulence spectra and energy budget were investigated based on eddy covariance method over an open-water highland lake (Erhai Lake) in Southwest China. We estimated the annual total evaporation and CO2 emission from the lake, and the evaporation trend in the past few decades was also discussed. Due to the large thermal inertia of lake water, the surface water temperature lagged behind the air temperature. Maximum lake-air temperature difference of about 4 °C had been observed in November. Water temperature profile measurements revealed that the stratification of lake water was not evident throughout the year. The spectra and cospectra of wind speed and temperature roughly satisfied the -2/3 and -4/3 rule in inertial subrange, respectively. The w spectra were observed to have a larger contribution from higher frequencies than other variables. Obvious shifts of spectra and cospectra peaks toward higher frequencies were observed as the atmospheric stratification became more stable. The lake acted as a heat sink from March through June and quickly released heat into the atmosphere from September through December. Average energy balance closure for the lake was about 80 % in 2012. The lake majorly acted as a source of CO2 to the atmosphere, but weak sinks of CO2 were observed in the summer and early fall. The total annual emission of CO2 was estimated to be 333.28 g C m-2 year-1. The annual evaporation over the lake decreased due to the increased amount of low cloud and precipitation, with the lower annual evaporation in the 1990s compared to that in the 1980s.

  9. DCS Budget Tracking System

    Data.gov (United States)

    Social Security Administration — DCS Budget Tracking System database contains budget information for the Information Technology budget and the 'Other Objects' budget. This data allows for monitoring...

  10. Heat Loss of the Earth and Energy Budget of the Mantle

    Science.gov (United States)

    Mareschal, J.; Jaupart, C.

    2009-05-01

    Determination of the rate of Earth's energy loss is based a very large number of heat flux measurements in a variety of geological settings. Difficulties in integrating the flux over the Earth surface stem from two facts. One is that heat flux varies on a wide range of spatial scales and, in continents, is not a function of a single variable such as geological age, for example. The other difficulty is that the data exhibit large scatter. Advances in the interpretation of oceanic heat flux data are due to a thorough understanding of hydrothermal circulation through oceanic crust and sediments. In continents, the total heat loss has been constrained by sampling of old cratons is now adequate and systematic studies of heat flux and heat production have provided robust constraints on the crustal contribution to the surface heat flux. Heat loss through the ocean floor cannot be determined from the raw data because they are affected by hydrothermal circulation and irregularities in sediment cover. Predictions of the "half-space" model for the conductive cooling of oceanic lithosphere are consistent with heat flux measurements in selected "noise-free" environments as well as with the bathymetry of the sea floor. They are also consistent with values of the mantle temperature beneath oceanic ridges derived from petrology. This cooling model is also consistent with numerical calculations of mantle convection with plates. Using an accurate determination of the area extent of oceanic sea floor including marginal basins and accounting for enhanced heat flux over hot spots, we estimated the rate of heat loss through the oceans to be 32±2 TW (1012 Watts). This result is valid only for the present-day age distribution of sea floor and heat loss may have been different in the past when the distribution of sea floor ages was different from the present. For continents, bias due to the very uneven sampling of the surface heat flux is removed by area- weighting the average. The

  11. Contrasting responses of urban and rural surface energy budgets to heat waves explain synergies between urban heat islands and heat waves

    Science.gov (United States)

    Li, Dan; Sun, Ting; Liu, Maofeng; Yang, Long; Wang, Linlin; Gao, Zhiqiu

    2015-05-01

    Heat waves (HWs) are projected to become more frequent and last longer over most land areas in the late 21st century, which raises serious public health concerns. Urban residents face higher health risks due to synergies between HWs and urban heat islands (UHIs) (i.e., UHIs are higher under HW conditions). However, the responses of urban and rural surface energy budgets to HWs are still largely unknown. This study analyzes observations from two flux towers in Beijing, China and reveals significant differences between the responses of urban and rural (cropland) ecosystems to HWs. It is found that UHIs increase significantly during HWs, especially during the nighttime, implying synergies between HWs and UHIs. Results indicate that the urban site receives more incoming shortwave radiation and longwave radiation due to HWs as compared to the rural site, resulting in a larger radiative energy input into the urban surface energy budget. Changes in turbulent heat fluxes also diverge strongly for the urban site and the rural site: latent heat fluxes increase more significantly at the rural site due to abundant available water, while sensible heat fluxes and possibly heat storage increase more at the urban site. These comparisons suggest that the contrasting responses of urban and rural surface energy budgets to HWs are responsible for the synergies between HWs and UHIs. As a result, urban mitigation and adaption strategies such as the use of green roofs and white roofs are needed in order to mitigate the impact of these synergies.

  12. Who needs budgets?

    Science.gov (United States)

    Hope, Jeremy; Fraser, Robin

    2003-02-01

    Budgeting, as most corporations practice it, should be abolished. That may sound radical, but doing so would further companies' long-running efforts to transform themselves into developed networks that can nimbly adjust to market conditions. Most other building blocks are in place, but companies continue to restrict themselves by relying on inflexible budget processes and the command-and-control culture that budgeting entails. A number of companies have rejected the foregone conclusions embedded in budgets, and they've given up the self-interested wrangling over what the data indicate. In the absence of budgets, alternative goals and measures--some financial, such as cost-to-income ratios, and some nonfinancial, such as time to market-move to the foreground. Companies that have rejected budgets require employees to measure themselves against the performance of competitors and against internal peer groups. Because employees don't know whether they've succeeded until they can look back on the results of a given period, they must use every ounce of energy to ensure that they beat the competition. A key feature of many companies that have rejected budgets is the use of rolling forecasts, which are created every few months and typically cover five to eight quarters. Because the forecasts are regularly revised, they allow companies to continuously adapt to market conditions. The forecasting practices of two such companies, both based in Sweden, are examined in detail: the bank Svenska Handelsbanken and the wholesaler Ahlsell. Though the first companies to reject budgets were located in Northern Europe, organizations that have gone beyond budgeting can be found in a range of countries and industries. Their practices allow them to unleash the power of today's management tools and realize the potential of a fully decentralized organization.

  13. Effects of the Amplitude and Frequency of Salinity Fluctuation on the Body Composition and Energy Budget of Juvenile Tongue Sole (Cynoglossus semilaevis)

    Institute of Scientific and Technical Information of China (English)

    Sachin Onkar KHAIRNAR; TIAN Xiangli; FANG Ziheng; DONG Shuanglin

    2015-01-01

    Effects of the amplitude (±2, ±4, ±6, and ±8) and frequency (2, 4, and 8d) of salinity fluctuation on the body composi-tion and energy budget of juvenile tongue sole (Cynoglossus semilaevis) were investigated in a 64-d experiment. Results showed that the amplitude and frequency of salinity fluctuation had significant interaction and both substantially affected the final weight and specific growth rate of juvenile tongue sole. The tongue sole exhibited better growth in treatments with moderate amplitude and fre-quency of salinity fluctuation (amplitude ±4–6; frequency 4–8d) than in other treatments and the control. In terms of energy budget, salinity fluctuation strongly affected the proportions of energy components, including those deposited for growth and lost in respira-tion, feces, and excretion. Moderately amplitude and frequency of salinity fluctuationg that favored the growth of tongue sole parti-tioned more energy for growth and less energy for metabolism than the constant and other amplitude and frequency of salinity fluc-tuation. Average energy budget for tongue sole at moderately fluctuating salinity was determined to be 100C(food)=30.92G(growth) +10.30F(feces)+6.77U(excretion)+52.01R(respiration). Energetic advantage at moderately fluctuating salinity, including increased energy intake, high assimilation efficiency, reduced metabolism expenditure, and more energy partitioned into growth, might account for the enhancement of tongue sole growth. Commercial farmers are recommended to rear juvenile tongue sole with moderate salin-ity fluctuations for better growth performance of this species.

  14. Estimation of surface heat and moisture fluxes over a prairie grassland. I - In situ energy budget measurements incorporating a cooled mirror dew point hygrometer

    Science.gov (United States)

    Smith, Eric A.; Crosson, William L.; Tanner, Bertrand D.

    1992-01-01

    Attention is focused on in situ measurements taken during FIFE required to support the development and validation of a biosphere model. Seasonal time series of surface flux measurements obtained from two surface radiation and energy budget stations utilized to support the FIFE surface flux measurement subprogram are examined. Data collection and processing procedures are discussed along with the measurement analysis for the complete 1987 test period.

  15. Tropical Ocean Evaporation/SST Sensitivity and It's Link to Water and Energy Budget Variations During ENSO

    Science.gov (United States)

    Robertson, Franklin R.; Marshall, Susan; Oglesby, Robert; Roads, John; Sohn, Byung-Ju; Arnold, James E. (Technical Monitor)

    2001-01-01

    The continuing debate over feedback mechanisms governing tropical sea surface temperatures (SSTs) and tropical climate in general has highlighted the diversity of potential checks and balances within the climate system. Competing feedbacks due to changes in surface evaporation, water vapor, and cloud long- and shortwave radiative properties each may serve critical roles in stabilizing or destabilizing the climate system. It is also intriguing that even those climate variations having origins internal to the climate system - changes in ocean heat transport for example, apparently require complementary equilibrating effects by changes in atmospheric energy fluxes. Perhaps the best observational evidence of this is the relatively invariant nature of tropically averaged net radiation exiting the top-of-atmosphere (TOA) as measured by broadband satellite sensors over the past two decades. Thus, analyzing how these feedback mechanisms are operating within the context of current interannual variability may offer considerable insight for anticipating future climate change. In this paper we focus primarily on interannual variations of ocean evaporative fluxes and their significance for coupled water and energy cycles within the tropical climate system. In particular, we use both the da Silva estimates of surface fluxes (based on the Comprehensive Ocean Atmosphere Data Set, COADS) and numerical simulations from several global climate models to examine evaporation sensitivity to perturbations in SST associated with warm and cold ENSO events. The specific questions we address are as follows: (1) What recurring patterns of surface wind and humidity anomalies are present during ENSO and how do they combine to yield systematic evaporation anomalies?, (2) What is the resulting tropical ocean mean evaporation-SST sensitivity associated with this climate perturbation?, and (3) What role does this evaporation play in tropical heat and water balance over tropical oceanic regions? We

  16. Climate change impact assessment on mountain snow hydrology by water and energy budget-based distributed hydrological model

    Science.gov (United States)

    Bhatti, Asif M.; Koike, Toshio; Shrestha, Maheswor

    2016-12-01

    A water and energy budget-based distributed hydrological model with improved snow physics (WEB-DHM-S) was applied to elucidate the impact of climate change on mountain snow hydrology in the Shubuto River basin, Hokkaido, Japan. The simulated spatial distribution of snow cover was evaluated using the Moderate Resolution Imaging Spectroradiometer (MODIS) 8-day maximum snow-cover extent (MOD10A2) product, which revealed the model's capability for capturing the spatiotemporal variations in snow cover within the study area. Four Atmosphere Ocean General Circulation Models (AOGCMs) were selected and the SRESA1B emission scenario of the Intergovernmental Panel on Climate Change was used to describe climate predictions in the basin. All AOGCMs predict a future decrease in snowmelt contribution to total discharge 11-22% and an average decrease in SWE of 36%, with a shift in peak SWE by 4-14 days. The shift in runoff regime is broadly consistent between the AOGCMs with snowmelt-induced peak discharge expected to occur on average about two weeks earlier in the future hydrological year. The warming climate will drive a shift in runoff regime from a combined rainfall- and snowmelt-driven regime to one with a reduced contribution from snowmelt. The results of the study revealed that the model could be successfully applicable on the basin scale to simulate river discharge and snow processes and to investigate the effect of climate change on hydrological processes. This research contributes to improve the understanding of basin hydrological responses and the pace of change associated with climate variability.

  17. The 1985 Biomass Burning Season in South America: Satellite Remote Sensing of Fires, Smoke, and Regional Radiative Energy Budgets

    Science.gov (United States)

    Christopher, Sundar A.; Wang, Min; Berendes, Todd A.; Welch, Ronald M.; Yang, Shi-Keng

    1998-01-01

    Using satellite imagery, more than five million square kilometers of the forest and cerrado regions over South America are extensively studied to monitor fires and smoke during the 1985 biomass burning season. The results are characterized for four major ecosystems, namely: (1) tropical rain forest, (2) tropical broadleaf seasonal, (3) savannah/grass and seasonal woods (SGW), and (4) mild/warm/hot grass/shrub (MGS). The spatial and temporal distribution of fires are examined from two different methods using the multispectral Advanced Very High Resolution Radiometer Local Area Coverage data. Using collocated measurements from the instantaneous scanner Earth Radiation Budget Experiment data, the direct regional radiative forcing of biomass burning aerosols is computed. The results show that more than 70% of the fires occur in the MGS and SGW ecosystems due to agricultural practices. The smoke generated from biomass burning has negative instantaneous net radiative forcing values for all four major ecosystems within South America. The smoke found directly over the fires has mean net radiative forcing values ranging from -25.6 to -33.9 W m(exp -2). These results confirm that the regional net radiative impact of biomass burning is one of cooling. The spectral and broadband properties for clear-sky and smoke regions are also presented that could be used as input and/or validation for other studies attempting to model the impact of aerosols on the earth-atmosphere system. These results have important applications for future instruments from the Earth Observing System (EOS) program. Specifically, the combination of the Visible Infrared Scanner and Clouds and the Earth's Radiant Energy System (CERES) instruments from the Tropical Rainfall Measuring Mission and the combination of Moderate Resolution Imaging Spectrometer and CERES instruments from the EOS morning crossing mission could provide reliable estimates of the direct radiative forcing of aerosols on a global scale

  18. The importance of large benthic foraminifera to reef island sediment budget and dynamics at Raine Island, northern Great Barrier Reef

    Science.gov (United States)

    Dawson, John L.; Smithers, Scott G.; Hua, Quan

    2014-10-01

    Low-lying reef islands are among the most vulnerable environments on earth to anthropogenic-induced climate change and sea-level rise over the next century because they are low, composed of unconsolidated sediment that is able to be mobilised by waves and currents, and depend on sediments supplied by reef organisms that are particularly sensitive to environmental changes (e.g. ocean temperatures and chemistry). Therefore, the spatial and temporal links between active carbonate production and island formation and dynamics are fundamental to predicting future island resilience, yet remain poorly quantified. In this paper we present results of a detailed geomorphological and sedimentological study of a reef and sand cay on the northern Great Barrier Reef. We provide an empirical investigation of the temporal linkages between sediment production and reef island development using a large collection of single grain AMS 14C dates. Large benthic foraminifera (LBF) are the single most important contributor to contemporary island sand mass (47%; ranging from 36% to 63%) at Raine Island, reflecting rapid rates of sediment production and delivery. Standing stock data reveal extremely high production rates on the reef (1.8 kg m- 2 yr- 1), while AMS 14C dates of single LBF tests indicate rapid rates of sediment transferral across the reef. We also demonstrate that age is statistically related to preservation and taphonomic grade (severely abraded tests > moderately abraded tests > pristine tests). We construct a contemporary reef and island sediment budget model for Raine Island that shows that LBF (Baculogypsina, Marginopora and Amphistegina) contribute 55% of the sediment produced on the reef annually, of which a large proportion (54%) contribute to the net annual accretion of the island. The tight temporal coupling between LBF growth and island sediment supply combined with the sensitivity of LBF to bleaching and ocean acidification suggests that islands dominated by LBF are

  19. Molecular Dynamics Studies of Energy Transfer Processes in Crystal Systems.

    Science.gov (United States)

    1984-11-30

    Computer molecular dynamics studies have been carried out on the problem of attaining a fundamental understanding of shock-induced initiation of...intramolecular energy exchange in shock-loaded systems are presented. Originator-supplied keywords include: Molecular dynamics , Energy transfer, Shock front, Shock wave, Explosives, Shock structure.

  20. Energy conservation in molecular dynamics simulations of classical systems

    DEFF Research Database (Denmark)

    Toxværd, Søren; Heilmann, Ole; Dyre, J. C.

    2012-01-01

    Classical Newtonian dynamics is analytic and the energy of an isolated system is conserved. The energy of such a system, obtained by the discrete “Verlet” algorithm commonly used in molecular dynamics simulations, fluctuates but is conserved in the mean. This is explained by the existence...

  1. EXPENSES FOR ECONOMIC ACTIVITIES FROM LOCAL BUDGETS

    Directory of Open Access Journals (Sweden)

    CRISTINEL ICHIM

    2015-04-01

    Full Text Available In the present article we propose to analyze and deepen significant categories of costs funded from the local budgets, namely the expenditure for economic activities. Our scientific approach begins with determining the place occupied by such expenses in local public expenditure by specifying their content and role. The center of gravity of the study is to treat and deepen the three subgroups of expenses that we consider representative: "The expenses for production, transportation, distribution and supply of heat in a centralized system", "Transport Costs" and Expenditure for agriculture and forestry ". The reaserch is based on the quantitative analysis of the expenses for economic actions, in local budgets, based on the existing data from the Statistical Yearbook of Romania, and highlights the structure of this type of expenses as well as the place they hold in the expediture of local budgets.The study includes an analysis of the dynamics of the share held by economic costs within total expenses from local budgets. From the reaserch carried out, it is shown that the evolution and structure of the expenditures for economic actions from local budgets is determined by the action of certain economical and social factors that vary from one administrative teritorial unit to another: the ray of economical develpoment of the administrative ter itorial unit, urbanization, the number and social structure of the population. The reaserch shows that in the field of expenses for economic actions, the largest share is held by expenditures for transportation (almost 80%, far away from the expenses for fuel and energy (13,66%. During the 1999-2013 the dynamic of expenses for economical actions in the total of expenditures of local budgets, is sinusoidal due to the intervention of certain legislative changes.

  2. European Union Budget Politics

    DEFF Research Database (Denmark)

    Citi, Manuele

    2015-01-01

    The marginal involvement of the European Union (EU) in redistributive policies and its limited fiscal resources have led to a notable lack of attention by EU scholars towards the EU budget and its dynamics. Yet the nature of the budgetary data and their high usability for statistical analysis make...

  3. Device for separation of vortex gas-dynamic energy

    Science.gov (United States)

    Leontiev, A. I.; Burtsev, S. A.

    2015-10-01

    A device for separation of vortex gas-dynamic energy, which combines the mechanism of separation of vortex energy used in the Ranque-Hilsch tubes and the mechanism of separation of gas-dynamic energy, is proposed for supersonic flows. A method of calculation of this device is developed. A comparison is made that showed that, when working with natural gas, the cooling depth of half of the mass flow rate proves to be 1.3 times higher than that for the vortex tube and three times higher than that for the device for separation of the gas-dynamic energy.

  4. Evaluating the performance of land surface model ORCHIDEE-CAN v1.0 on water and energy flux estimation with a single- and multi-layer energy budget scheme

    Science.gov (United States)

    Chen, Yiying; Ryder, James; Bastrikov, Vladislav; McGrath, Matthew J.; Naudts, Kim; Otto, Juliane; Ottlé, Catherine; Peylin, Philippe; Polcher, Jan; Valade, Aude; Black, Andrew; Elbers, Jan A.; Moors, Eddy; Foken, Thomas; van Gorsel, Eva; Haverd, Vanessa; Heinesch, Bernard; Tiedemann, Frank; Knohl, Alexander; Launiainen, Samuli; Loustau, Denis; Ogée, Jérôme; Vessala, Timo; Luyssaert, Sebastiaan

    2016-09-01

    Canopy structure is one of the most important vegetation characteristics for land-atmosphere interactions, as it determines the energy and scalar exchanges between the land surface and the overlying air mass. In this study we evaluated the performance of a newly developed multi-layer energy budget in the ORCHIDEE-CAN v1.0 land surface model (Organising Carbon and Hydrology In Dynamic Ecosystems - CANopy), which simulates canopy structure and can be coupled to an atmospheric model using an implicit coupling procedure. We aim to provide a set of acceptable parameter values for a range of forest types. Top-canopy and sub-canopy flux observations from eight sites were collected in order to conduct this evaluation. The sites crossed climate zones from temperate to boreal and the vegetation types included deciduous, evergreen broad-leaved and evergreen needle-leaved forest with a maximum leaf area index (LAI; all-sided) ranging from 3.5 to 7.0. The parametrization approach proposed in this study was based on three selected physical processes - namely the diffusion, advection, and turbulent mixing within the canopy. Short-term sub-canopy observations and long-term surface fluxes were used to calibrate the parameters in the sub-canopy radiation, turbulence, and resistance modules with an automatic tuning process. The multi-layer model was found to capture the dynamics of sub-canopy turbulence, temperature, and energy fluxes. The performance of the new multi-layer model was further compared against the existing single-layer model. Although the multi-layer model simulation results showed few or no improvements to both the nighttime energy balance and energy partitioning during winter compared with a single-layer model simulation, the increased model complexity does provide a more detailed description of the canopy micrometeorology of various forest types. The multi-layer model links to potential future environmental and ecological studies such as the assessment of in

  5. Projected Impact of Climate Change on the Energy Budget of the Arctic Ocean by a Global Climate Model

    Science.gov (United States)

    Miller, James R.; Russell, Gary L.; Hansen, James E. (Technical Monitor)

    2001-01-01

    The annual energy budget of the Arctic Ocean is characterized by a net heat loss at the air-sea interface that is balanced by oceanic heat transport into the Arctic. The energy loss at the air-sea interface is due to the combined effects of radiative, sensible, and latent heat fluxes. The inflow of heat by the ocean can be divided into two components: the transport of water masses of different temperatures between the Arctic and the Atlantic and Pacific Oceans and the export of sea ice, primarily through Fram Strait. Two 150-year simulations (1950-2099) of a global climate model are used to examine how this balance might change if atmospheric greenhouse gases (GHGs) increase. One is a control simulation for the present climate with constant 1950 atmospheric composition, and the other is a transient experiment with observed GHGs from 1950 to 1990 and 0.5% annual compounded increases of CO2 after 1990. For the present climate the model agrees well with observations of radiative fluxes at the top of the atmosphere, atmospheric advective energy transport into the Arctic, and surface air temperature. It also simulates the seasonal cycle and summer increase of cloud cover and the seasonal cycle of sea-ice cover. In addition, the changes in high-latitude surface air temperature and sea-ice cover in the GHG experiment are consistent with observed changes during the last 40 and 20 years, respectively. Relative to the control, the last 50-year period of the GHG experiment indicates that even though the net annual incident solar radiation at the surface decreases by 4.6 W(per square meters) (because of greater cloud cover and increased cloud optical depth), the absorbed solar radiation increases by 2.8 W(per square meters) (because of less sea ice). Increased cloud cover and warmer air also cause increased downward thermal radiation at the surface so that the net radiation into the ocean increases by 5.0 Wm-2. The annual increase in radiation into the ocean, however, is

  6. Coherent dynamics in solar energy transduction

    NARCIS (Netherlands)

    Eisenmayer, Thomas J.

    2014-01-01

    This thesis is concerned with the transfer of energy from light to matter. Over a century ago it was established that light consists of packets of energy [1], now known as photons. Not much later the energy levels of matter at the atomic scale were found to be discrete [2]. These phenomena required

  7. El Chichón crater lake dynamic based on continuous physical data and mass-heat budget

    Science.gov (United States)

    Peiffer, L.; Taran, Y.

    2011-12-01

    The March-April 1982 Plinian eruption of El Chichón volcano destroyed the summit domes system and created a new 200 m deep crater. Since then, a shallow lake (~3 m) with acidic pH (~2.3), and temperature around 30°C appeared in the crater. This lake has never disappeared until now although its volume has suffered important variations from 40,000 m3 to 160,000 m3. Chemical composition of the lake is also highly variable (Cl/SO4 = 0-79 molar ratio), alternating between acid-sulfate and acid-chloride-sulfate composition. These variations can occur very fast within few weeks and are not directly correlated with precipitation. Due to its shallow depth and small volume, El Chichón crater lake is probably one of the most dynamic crater lake on earth. These rapid changes in chemistry and volume reflect the dynamic of one group of geyser-type springs ('Soap Pools springs, SP') located offshore and the input of hydrothermal steam underneath the crater. The SP springs discharge sporadically to the lake neutral waters with Cl content currently around 3000 mg/l, while the condensed steam feeds the lake with Cl-free and SO4-rich acid water. In this study, we present for the first time continuous physical data of the crater lake (temperature, depth, meteoric precipitation, wind velocity, solar radiation, air humidity). These data were registered by a meteorological station and two dataloggers installed inside and outside the lake. Using a mass and heat budget model constrained with these data, we were able to estimate the flux of 'hydrothermal' fluid entering the lake through the sub-lacustrian fumaroles and SP springs. Tracing the variations of the input flux in time can be help to understand the dynamic of the 'crater lake-SP springs-fumaroles' system but also can provide an efficient way of monitoring the volcanic activity. During the observation period, the mean mass flux entering the lake (Min) was respectively of 12 ± 2 kg/s, corresponding to a total heat flux (Ein) of

  8. Impacts of Boreal Forest Fires and Post-Fire Succession on Energy Budgets and Climate in the Community Earth System Model

    Science.gov (United States)

    Rogers, B. M.; Randerson, J. T.; Bonan, G. B.

    2011-12-01

    Vegetation compositions of boreal forests are determined largely by recovery patterns after large-scale disturbances, the most notable of which is wildfire. Forest compositions exert large controls on regional energy and greenhouse gas budgets by affecting surface albedo, net radiation, turbulent energy fluxes, and carbon stocks. Impacts of boreal forest fires on climate are therefore products of direct fire effects, including charred surfaces and emitted aerosols and greenhouse gasses, and post-fire vegetation succession, which affects carbon and energy exchange for many decades after the initial disturbance. Climate changes are expected to be greatest at high latitudes, leading many to project increases in boreal forest fires. While numerous studies have documented the effects of post-fire landscape on energy and gas budgets in boreal forests, to date no continental analysis using a coupled model has been performed. In this study we quantified the effects of boreal forest fires and post-fire succession on regional and global climate using model experiments in the Community Earth System Model. We used 20th century climate data and MODIS vegetation continuous fields and land cover classes to identify boreal forests across North America and Eurasia. Historical fire return intervals were derived from a regression approach utilizing the Canadian and Alaskan Large Fire Databases, the Global Fire Emissions Database v3, and land cover and climate data. Succession trajectories were derived from the literature and MODIS land cover over known fire scars. Major improvements in model-data comparisons of long-term energy budgets were observed by prescribing post-fire vegetation succession. Global simulations using historical and future burn area scenarios highlight the potential impacts on climate from changing fire regimes and provide motivation for including vegetation succession in coupled simulations.

  9. Dynamic modeling, simulation and control of energy generation

    CERN Document Server

    Vepa, Ranjan

    2013-01-01

    This book addresses the core issues involved in the dynamic modeling, simulation and control of a selection of energy systems such as gas turbines, wind turbines, fuel cells and batteries. The principles of modeling and control could be applied to other non-convention methods of energy generation such as solar energy and wave energy.A central feature of Dynamic Modeling, Simulation and Control of Energy Generation is that it brings together diverse topics in thermodynamics, fluid mechanics, heat transfer, electro-chemistry, electrical networks and electrical machines and focuses on their appli

  10. Source identification and budget analysis on elevated levels of formaldehyde within ship plumes: a photochemical/dynamic model analysis

    Science.gov (United States)

    Song, C. H.; Kim, H. S.; von Glasow, R.; Brimblecombe, P.; Kim, J.; Park, R. J.; Woo, J. H.

    2010-06-01

    Elevated levels of formaldehyde (HCHO) along the ship corridors have been observed by satellite sensors, such as ESA/ERS-2 GOME (Global Ozone Monitoring Experiment), and were also predicted by global 3-D chemistry-transport models. In this study, three likely sources of the elevated HCHO levels were investigated to identify the detailed sources and examine the contributions of the sources (budget) of the elevated levels of HCHO in the ship corridors using a newly-developed ship-plume photochemical/dynamic model: (1) primary HCHO emission from ships; (2) secondary HCHO production via the atmospheric oxidation of Non-methane volatile organic compounds (NMVOCs) emitted from ships; and (3) atmospheric oxidation of CH4 within the ship plumes. From multiple ship-plume model simulations, CH4 oxidation by elevated levels of in-plume OH radicals was found to be the main factor responsible for the elevated levels of HCHO in the ship corridors. More than ~91% of the HCHO for the base ship plume case (ITCT 2K2 ship-plume case) is produced by this atmospheric chemical process, except in the areas close to the ship stacks where the main source of the elevated HCHO levels would be primary HCHO from the ships (due to the deactivation of CH4 oxidation from the depletion of in-plume OH radicals). Because of active CH4 oxidation (chemical destruction of CH4) by OH radicals, the instantaneous chemical lifetime of CH4 (τ CH4) decreased to ~0.45 yr inside the ship plume, which is in contrast to τ CH4 of ~1.1 yr in the background (up to ~41% decrease). A variety of likely ship-plume situations at three locations at different latitudes within the global ship corridors was also studied to determine the extent of the enhancements in the HCHOlevels in the marine boundary layer (MBL) influenced by ship emissions. It was found that the ship-plume HCHO levels could be 20.5-434.9 pptv higher than the background HCHO levels depending on the latitudinal locations of the ship plumes (i

  11. Perspective: Dynamic Shadowing Growth and its Energy Applications

    Directory of Open Access Journals (Sweden)

    Yiping eZhao

    2014-09-01

    Full Text Available The unique features of dynamic shadowing growth (DSG in structural and compositional design of nanomaterials are discussed. Their recent applications in energy storage, fuel cell, and solar energy conversion have been reviewed briefly. Future directions for applying DSG nanostructures in renewable energy applications are presented.

  12. Computational Fluid Dynamics and Building Energy Performance Simulation

    DEFF Research Database (Denmark)

    Nielsen, Peter Vilhelm; Tryggvason, T.

    1998-01-01

    An interconnection between a building energy performance simulation program and a Computational Fluid Dynamics program (CFD) for room air distribution will be introduced for improvement of the predictions of both the energy consumption and the indoor environment. The building energy performance...

  13. Parton-Hadron-String Dynamics at Relativistic Collider Energies

    CERN Document Server

    Bratkovskaya, E L; Konchakovski, V P; Linnyk, O

    2011-01-01

    The novel Parton-Hadron-String Dynamics (PHSD) transport approach is applied to nucleus-nucleus collisions at RHIC energies with respect to differential hadronic spectra in comparison to available data. The PHSD approach is based on a dynamical quasiparticle model for partons (DQPM) matched to reproduce recent lattice-QCD results from the Wuppertal-Budapest group in thermodynamic equilibrium. The transition from partonic to hadronic degrees of freedom is described by covariant transition rates for the fusion of quark-antiquark pairs or three quarks (antiquarks), respectively, obeying flavor current-conservation, color neutrality as well as energy-momentum conservation. Our dynamical studies for heavy-ion collisions at relativistic collider energies are compared to earlier results from the Hadron-String Dynamics (HSD) approach - incorporating no explicit dynamical partonic phase - as well as to experimental data from the STAR, PHENIX, BRAHMS and PHOBOS collaborations for Au+Au collisions at the top RHIC energy...

  14. NVU dynamics. III. Simulating molecules at constant potential energy

    DEFF Research Database (Denmark)

    Ingebrigtsen, Trond; Dyre, J. C.

    2012-01-01

    This is the final paper in a series that introduces geodesic molecular dynamics at constant potential energy. This dynamics is entitled NVU dynamics in analogy to standard energy-conserving Newtonian NVE dynamics. In the first two papers [T. S. Ingebrigtsen, S. Toxvaerd, O. J. Heilmann, T. B....... In this paper, the NVU algorithm for atomic systems is extended to be able to simulate the geodesic motion of molecules at constant potential energy. We derive an algorithm for simulating rigid bonds and test this algorithm on three different systems: an asymmetric dumbbell model, Lewis-Wahnström o......-terphenyl (OTP) and rigid SPC/E water. The rigid bonds introduce additional constraints beyond that of constant potential energy for atomic systems. The rigid-bond NVU algorithm conserves potential energy, bond lengths, and step length for indefinitely long runs. The quantities probed in simulations give results...

  15. Energy flow theory of nonlinear dynamical systems with applications

    CERN Document Server

    Xing, Jing Tang

    2015-01-01

    This monograph develops a generalised energy flow theory to investigate non-linear dynamical systems governed by ordinary differential equations in phase space and often met in various science and engineering fields. Important nonlinear phenomena such as, stabilities, periodical orbits, bifurcations and chaos are tack-led and the corresponding energy flow behaviors are revealed using the proposed energy flow approach. As examples, the common interested nonlinear dynamical systems, such as, Duffing’s oscillator, Van der Pol’s equation, Lorenz attractor, Rössler one and SD oscillator, etc, are discussed. This monograph lights a new energy flow research direction for nonlinear dynamics. A generalised Matlab code with User Manuel is provided for readers to conduct the energy flow analysis of their nonlinear dynamical systems. Throughout the monograph the author continuously returns to some examples in each chapter to illustrate the applications of the discussed theory and approaches. The book can be used as ...

  16. Dynamic Energy Budgets and Bioaccumulation: A Model for Marine Mammals and Marine Mammal Populations

    Science.gov (United States)

    2006-06-01

    Orcinus orca : Effects of age, sex and dietary preference. Marine Pollution Bulletin 40:504 74 515. Schwacke, L. H., E. 0. Voit, L. J. Hansen, R. S...requirements for maintenance and growth of captive harbour seals, Phoca Goenlandica. Canadian Journal of Zoology 68:423-426. McCauley, E., Roger, R.M., de

  17. Molecular Dynamics of Materials Possessing High Energy Content.

    Science.gov (United States)

    1988-01-26

    I -RI90 634 MOLECULAR DYNAMICS OF MATERIALS POSSESSING HIGH ENERGY 1/1 r CONTENTCU) COLUMBIA UNIV MENd YORK N J TURRO 26 JAN GO I RFOSR-TR-88-0168...Bolling Air Force Base, D.C. 2 61102F_ 2303 I B2 11 T,TL.E (Inciuoe Security Classification) Molecular Dynamics of Materials Possessing High Energy...York 10027 (212) 280-2175 TITLE: MOLECULAR DYNAMICS OF MATERIALS POSSESSING HIGH ENERGY CONTENT .. 0 0 88 2 ... "" ’% ,i u , . .. .. ....... ŝ" ;! ,i

  18. Dynamics of Interacting Tachyonic Teleparallel Dark Energy

    Directory of Open Access Journals (Sweden)

    Ali Banijamali

    2014-01-01

    Full Text Available We consider a tachyon scalar field which is nonminimally coupled to gravity in the framework of teleparallel gravity. We analyze the phase-space of the model, known as tachyonic teleparallel dark energy, in the presence of an interaction between dark energy and background matter. We find that although there exist some late-time accelerated attractor solutions, there is no scaling attractor. So, unfortunately interacting tachyonic teleparallel dark energy cannot alleviate the coincidence problem.

  19. Hawaii energy strategy project 2: Fossil energy review. Task 1: World and regional fossil energy dynamics

    Energy Technology Data Exchange (ETDEWEB)

    Breazeale, K. [ed.; Isaak, D.T.; Yamaguchi, N.; Fridley, D.; Johnson, C.; Long, S.

    1993-12-01

    This report in the Hawaii Energy Strategy Project examines world and regional fossil energy dynamics. The topics of the report include fossil energy characteristics, the world oil industry including reserves, production, consumption, exporters, importers, refining, products and their uses, history and trends in the global oil market and the Asia-Pacific market; world gas industry including reserves, production, consumption, exporters, importers, processing, gas-based products, international gas market and the emerging Asia-Pacific gas market; the world coal industry including reserves, classification and quality, utilization, transportation, pricing, world coal market, Asia-Pacific coal outlook, trends in Europe and the Americas; and environmental trends affecting fossil fuels. 132 figs., 46 tabs.

  20. Renewable energy innovations in Europe: A dynamic panel data approach

    OpenAIRE

    Ayari, N. (Nadia); Blazsek-Ayala, S.I. (Szabolcs István); Mendi, P. (Pedro)

    2011-01-01

    Abstract We investigate the determinants of renewable energy R&D intensity and the impact of renewable energy innovations on firm performance, using several dynamic panel data models. We estimate these models using a large data set of European firms from 19 different countries, with some patenting activity in areas related with renewable energies during the 1987-2007 period. Our results confirm our priors on the determinants of the rapid development of renewable energy R&D intensit...

  1. South African energy model: a system dynamics approach

    CSIR Research Space (South Africa)

    Musango, JK

    2009-07-01

    Full Text Available & Andrea Bassi2 1 Council for Scientific and Industrial Research (CSIR), South Africa 2Millenium Institute, Arlington (VA) International Conference of System Dynamics Society Albuquerque, New Mexico July 26 - 31, 2009 South African energy model: a...

  2. Energy transfer in double plate system dynamics

    Institute of Scientific and Technical Information of China (English)

    Katica (Stevanovic) Hedrih

    2008-01-01

    The study of energy transfer between coupled subsystems in a hybrid system is very important for applications. This paper presents an analytical analysis of energy transfer between plates of a visco-elastically connected double-plate system in free transversal vibrations. The analytical analysis shows that the visco-elastic connection between plates is responsible for the appearance of two-frequency regime in the time function, which corresponds to one eigen amplitude function of one mode, and also that time functions of different vibration modes are uncoupled, but energy transfer between plates in one eigen mode appears. It was shown for each shape of vibrations. Series of the two Lyapunov exponents corresponding to the one eigen amplitude mode are expressed by using the energy of the corresponding eigen amplitude time component.

  3. Stable schemes for dissipative particle dynamics with conserved energy

    Energy Technology Data Exchange (ETDEWEB)

    Stoltz, Gabriel, E-mail: stoltz@cermics.enpc.fr

    2017-07-01

    This article presents a new numerical scheme for the discretization of dissipative particle dynamics with conserved energy. The key idea is to reduce elementary pairwise stochastic dynamics (either fluctuation/dissipation or thermal conduction) to effective single-variable dynamics, and to approximate the solution of these dynamics with one step of a Metropolis–Hastings algorithm. This ensures by construction that no negative internal energies are encountered during the simulation, and hence allows to increase the admissible timesteps to integrate the dynamics, even for systems with small heat capacities. Stability is only limited by the Hamiltonian part of the dynamics, which suggests resorting to multiple timestep strategies where the stochastic part is integrated less frequently than the Hamiltonian one.

  4. Prediction-based Dynamic Energy Management in Wireless Sensor Networks

    Directory of Open Access Journals (Sweden)

    Dao-Wei Bi

    2007-03-01

    Full Text Available Energy consumption is a critical constraint in wireless sensor networks. Focusing on the energy efficiency problem of wireless sensor networks, this paper proposes a method of prediction-based dynamic energy management. A particle filter was introduced to predict a target state, which was adopted to awaken wireless sensor nodes so that their sleep time was prolonged. With the distributed computing capability of nodes, an optimization approach of distributed genetic algorithm and simulated annealing was proposed to minimize the energy consumption of measurement. Considering the application of target tracking, we implemented target position prediction, node sleep scheduling and optimal sensing node selection. Moreover, a routing scheme of forwarding nodes was presented to achieve extra energy conservation. Experimental results of target tracking verified that energy-efficiency is enhanced by prediction-based dynamic energy management.

  5. Dynamic energy absorption characteristics of hollow microlattice structures

    Energy Technology Data Exchange (ETDEWEB)

    Liu, YL; Schaedler, TA; Chen, X

    2014-10-01

    Hollow microlattice structures are promising candidates for advanced energy absorption and their characteristics under dynamic crushing are explored. The energy absorption can be significantly enhanced by inertial stabilization, shock wave effect and strain rate hardening effect. In this paper we combine theoretical analysis and comprehensive finite element method simulation to decouple the three effects, and then obtain a simple model to predict the overall dynamic effects of hollow microlattice structures. Inertial stabilization originates from the suppression of sudden crushing of the microlattice and its contribution scales with the crushing speed, v. Shock wave effect comes from the discontinuity across the plastic shock wave front during dynamic loading and its contribution scales with e. The strain rate effect increases the effective yield strength upon dynamic deformation and increases the energy absorption density. A mechanism map is established that illustrates the dominance of these three dynamic effects at a range of crushing speeds. Compared with quasi-static loading, the energy absorption capacity a dynamic loading of 250 m/s can be enhanced by an order of magnitude. The study may shed useful insight on designing and optimizing the energy absorption performance of hollow microlattice structures under various dynamic loads. (C) 2014 Elsevier Ltd. All rights reserved.

  6. Longitudinal dynamics and energy analysis for heavy haul trains

    Institute of Scientific and Technical Information of China (English)

    Qing Wu; Shihui Luo; Colin Cole

    2014-01-01

    Whole trip longitudinal dynamics and energy analysis of heavy haul trains are required by operators and manufacturers to enable optimisation of train controls and rolling stock components. A new technology named train dynamics and energy analyser/train simulator (TDEAS) has been developed by the State Key Laboratory of Trac-tion Power in China to perform detailed whole trip longi-tudinal train dynamics and energy analyses. Facilitated by a controller user interface and a graphic user interface, the TDEAS can also be used as a train driving simulator. This paper elaborates the modelling of three primary parts in the TDEAS, namely wagon connection systems, air brake systems and train energy components. TDEAS uses advanced wedge-spring draft gear models that can simulate a wider spectrum of friction draft gear behaviour. An effective and efficient air brake model that can simulate air brake systems in various train configurations has been integrated. In addition, TDEAS simulates the train energy on the basis of a detailed longitudinal train dynamics simulation, which enables a further perspective of the train energy composition and the overall energy consumption. To demonstrate the validity of the TDEAS, a case study was carried out on a 120-km-long Chinese railway. The results show that the employment of electric locomotives with regenerative braking could bring considerable energy benefits. Nearly 40 % of the locomotive energy usage could be collected from the dynamic brake system. Most of tractive energy was dissipated by propulsion resistance that accounted for 42.48 % of the total energy. Only a small amount of tractive energy was dissipated by curving resistance, air brake and draft gear systems.

  7. Experimental estimates of the energy budget of hydrothermal eruptions; application to 2012 Upper Te Maari eruption, New Zealand

    Science.gov (United States)

    Montanaro, Cristian; Scheu, Bettina; Cronin, Shane J.; Breard, Eric C. P.; Lube, Gert; Dingwell, Donald B.

    2016-10-01

    . Further, we tested dry samples at the same pressure and temperature conditions. Results showed that host rock lithology and state of the interstitial fluid was a major influence on the fragmentation and ejection processes, as well as the energy partitioning. Clasts were ejected with velocities of up to 160 m/s as recorded by high-speed camera. In addition to rare large clasts (analogous to ballistics), a large amount of fine and very fine (steam expansion, which best explains the dynamics of the westward (and most energetic) directed blast at Te Maari. Considering the steam flashing as the primary energy source, the experiments suggested that a minimum explosive energy of 7 ×1010 to 2 ×1012 J was involved in the Te Maari blast. Experimental studies under controlled conditions, compared closely to a field example are thus highly useful in providing new insights into the energy release and hazards associated with eruptions in hydrothermal areas.

  8. Energy deposition dynamics of femtosecond pulses in water

    CERN Document Server

    Minardi, Stefano; Gopal, Amrutha; Tamošauskas, Gintaras; Milián, Carles; Couairon, Arnaud; Pertsch, Thomas; Dubietis, Audrius

    2014-01-01

    We exploit inverse Raman scattering and solvated electron absorption to perform a quantitative characterization of the energy loss and ionization dynamics in water with tightly focused near-infrared femtosecond pulses. A comparison between experimental data and numerical simulations suggests that the ionization energy of water is 8 eV, rather than the commonly used value of 6.5 eV.

  9. An energy efficient dynamic gait for a Nao robot

    NARCIS (Netherlands)

    Sun, Zhenglong; Roos, Nico

    2014-01-01

    This paper presents a framework to generate energy efficient dynamic human-like walk for a Nao humanoid robot. We first extend the inverted pendulum model with the goal of finding an energy efficient and stable walking gait. In this model, we propose a leg control policy which utilizes joint stiffne

  10. Dynamical Effects on Jet Energy Loss in QCD Medium

    CERN Document Server

    Djordjevic, Magdalena

    2009-01-01

    Computation of radiative energy loss in a finite size dynamically screened QCD medium is a key ingredient for obtaining reliable predictions for jet quenching in ultra-relativistic heavy ion collisions. We develop a theory which allows calculating, to first order in the number of scattering centers, the energy loss of a heavy quark traveling through a finite size dynamical QCD medium. We show that the result for a dynamical medium is significantly larger compared to a medium consisting of randomly distributed static scattering centers. Therefore, a quantitative description of jet suppression at RHIC and LHC experiments must correctly account for the dynamics of the medium's constituents. Furthermore, qualitative predictions that come from this energy loss formalism are also presented.

  11. Analysis of Energy Efficiency in Dynamic Optical Networks Employing Solar Energy Sources

    DEFF Research Database (Denmark)

    Wang, Jiayuan; Fagertun, Anna Manolova; Ruepp, Sarah Renée

    2013-01-01

    The paper presents energy efficient routing in dynamic optical networks, where solar energy sources are employed for the network nodes. Different parameters are evaluated, including the number of nodes that have access to solar energy sources, the different maximum solar output power, traffic type...

  12. Fiscal year 1999 budget request for the Department of Energy. Hearings before the Committee on Energy and Natural Resources, US Senate, One Hundred Fifth Congress, Second Session, March 4, 1998

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1998-12-31

    This contains statements on the US DOE budget request for fiscal year 1999 by Hon. Daniel K. Akaka, Hawaii, Hon. Jeff Bingaman, New Mexico, Hon. Ben Nighthorse Campbell, Colorado, Hon. Larry E. Craig, Idaho, Hon. Slade Gorton, Washington, Hon. Rod Grams, Minnesota, Hon. Tim Johnson, South Dakota, Hon. Frank H. Murkowski, Hon. Federicao Pena, Secretary, Department of Energy, Hon. Gordon H. Smith, Oregon, Hon. Craig Thomas, Wyoming.

  13. Dynamical analysis for a vector-like dark energy

    Energy Technology Data Exchange (ETDEWEB)

    Landim, Ricardo C.G. [Instituto de Fisica, Universidade de Sao Paulo, Departamento de Fisica-Matematica, Sao Paulo, SP (Brazil)

    2016-09-15

    In this paper we perform a dynamical analysis for a vector field as a candidate for the dark energy, in the presence of a barotropic fluid. The vector is one component of the so-called cosmic triad, which is a set of three identical copies of an abelian field pointing mutually in orthogonal directions. In order to generalize the analysis, we also assumed the interaction between dark energy and the barotropic fluid, with a phenomenological coupling. Both matter and dark energy eras can be successfully described by the critical points, indicating that the dynamical system theory is a viable tool to analyze asymptotic states of such cosmological models. (orig.)

  14. Dynamics of dark energy with a coupling to dark matter

    CERN Document Server

    Boehmer, Christian G; Lazkoz, Ruth; Maartens, Roy

    2008-01-01

    Dark energy and dark matter are the dominant sources in the evolution of the late universe. They are currently only indirectly detected via their gravitational effects, and there could be a coupling between them without violating observational constraints. We investigate the background dynamics when dark energy is modelled as exponential quintessence, and is coupled to dark matter via simple models of energy exchange. We introduce a new form of dark sector coupling, which leads to a more complicated dynamical phase space and has a better physical motivation than previous mathematically similar couplings.

  15. Fluctuations and symmetry energy in nuclear fragmentation dynamics.

    Science.gov (United States)

    Colonna, M

    2013-01-25

    Within a dynamical description of nuclear fragmentation, based on the liquid-gas phase transition scenario, we explore the relation between neutron-proton density fluctuations and nuclear symmetry energy. We show that, along the fragmentation path, isovector fluctuations follow the evolution of the local density and approach an equilibrium value connected to the local symmetry energy. Higher-density regions are characterized by smaller average asymmetry and narrower isotopic distributions. This dynamical analysis points out that fragment final state isospin fluctuations can probe the symmetry energy of the density domains from which fragments originate.

  16. Coupled dark energy: a dynamical analysis with complex scalar field

    Energy Technology Data Exchange (ETDEWEB)

    Landim, Ricardo C.G. [Universidade de Sao Paulo, Instituto de Fisica, Caixa Postal 66318, Sao Paulo, SP (Brazil)

    2016-01-15

    The dynamical analysis for coupled dark energy with dark matter is presented, where a complex scalar field is taken into account and it is considered in the presence of a barothropic fluid. We consider three dark-energy candidates: quintessence, phantom, and tachyon. The critical points are found and their stabilities analyzed, leading to the three cosmological eras (radiation, matter, and dark energy), for a generic potential. The results presented here extend the previous analyses found in the literature. (orig.)

  17. Low-energy dynamics of gravitation

    Science.gov (United States)

    Torma, Tibor

    The present status of theories of quantum gravity are reviewed from the low energy point of view. String theory relates classical black-hole type solutions of Einstein- like equations (e.g. axidilaton gravity) to the string vacuum. Several such solutions are proposed and their properties are investigated, including their behavior under supersymmetry transformations. A general feature of all possible quantum theories of gravitation is that they lead to a field theory description at low (as compared to the Planck mass) energies. The theoretical consistency, uniqueness and consequences of such an effective theory are investigated. I show that a power counting theorem allows for the momentum expansion that defines the effective theory even in the presence of large masses. I also show that graviton-graviton scattering is free of potential infrared and collinear divergencies that plague perturbative discussions of Yang-Mills theories.

  18. Impact of fire on global land surface air temperature and energy budget for the 20th century due to changes within ecosystems

    Science.gov (United States)

    Li, Fang; Lawrence, David M.; Bond-Lamberty, Ben

    2017-04-01

    Fire is a global phenomenon and tightly interacts with the biosphere and climate. This study provides the first quantitative assessment and understanding of fire’s influence on the global annual land surface air temperature and energy budget through its impact on terrestrial ecosystems. Fire impacts are quantified by comparing fire-on and fire-off simulations with the Community Earth System Model (CESM). Results show that, for the 20th century average, fire-induced changes in terrestrial ecosystems significantly increase global land annual mean surface air temperature by 0.18 °C, decrease surface net radiation and latent heat flux by 1.08 W m-2 and 0.99 W m-2, respectively, and have limited influence on sensible heat flux (-0.11 W m-2) and ground heat flux (+0.02 W m-2). Fire impacts are most clearly seen in the tropical savannas. Our analyses suggest that fire increases surface air temperature predominantly by reducing latent heat flux, mainly due to fire-induced damage to the vegetation canopy, and decreases net radiation primarily because fire-induced surface warming significantly increases upward surface longwave radiation. This study provides an integrated estimate of fire and induced changes in ecosystems, climate, and energy budget at a global scale, and emphasizes the importance of a consistent and integrated understanding of fire effects.

  19. Computational Fluid Dynamics and Building Energy Performance Simulation

    DEFF Research Database (Denmark)

    Nielsen, Peter V.; Tryggvason, Tryggvi

    An interconnection between a building energy performance simulation program and a Computational Fluid Dynamics program (CFD) for room air distribution will be introduced for improvement of the predictions of both the energy consumption and the indoor environment. The building energy performance...... simulation program requires a detailed description of the energy flow in the air movement which can be obtained by a CFD program. The paper describes an energy consumption calculation in a large building, where the building energy simulation program is modified by CFD predictions of the flow between three...... program and a building energy performance simulation program will improve both the energy consumption data and the prediction of thermal comfort and air quality in a selected area of the building....

  20. Chemical dynamics in time and energy space

    Energy Technology Data Exchange (ETDEWEB)

    Myers, James Douglas [Univ. of California, Berkeley, CA (United States)

    1993-04-01

    The development of a versatile picosecond ultraviolet/vacuum ultraviolet temporal spectrometer and its potential use for measuring internal energy redistribution in isolated molecules are described in detail. A detailed description of the double-pass Nd:YAG amplifier and the dye amplifiers is given with the pulse energies achieved in the visible, ultraviolet, and vacuum ultraviolet. The amplified visible pulses are shown to be of sub-picosecond duration and near transform limited. The instrument`s temporal response (≤10 ps) is derived from an instrument limited measurement of the dissociation lifetime of methyl iodide at 266 nm. The methyl iodide experiment is used to discuss the various sources of noise and background signals that are intrinsic to this type of experiment. Non-time-resolved experiments measuring the branching ratio and kinetic energy distributions of products from the 193 nm photodissociation of cyclopentadiene and thiophene are presented. These studies were done using the molecular beam Photofragment Translational Spectroscopy (PTS) technique. The results from the cyclopentadiene experiment confirm that H atom elimination to yield the cyclopentadienyl radical is the dominant dissociation channel. A barrier of ≥5 kcal/mol can be understood in terms of the delocalization of the radical electron of the cyclopentadienyl fragment. A concerted elimination yielding cyclopropene and acetylene was also observed and is proposed to occur via a bicyclo-[2.1.0]pent-2-ene intermediate. Two other channels, yielding acetylene plus the CH2CHCH triplet carbene, and CH2 plus 1-buten-3-yne, are postulated to occur via ring opening. The implications of the experimental results for bulk thermal oxidation and pyrolysis models are discussed. The thiophene experiment shows six competing dissociation channels. The postulated intermediates for the various thiophene dissociation channels include bicyclo, ring opened, and possibly ring contracted

  1. Chemical dynamics in time and energy space

    Energy Technology Data Exchange (ETDEWEB)

    Myers, J.D.

    1993-04-01

    The development of a versatile picosecond ultraviolet/vacuum ultraviolet temporal spectrometer and its potential use for measuring internal energy redistribution in isolated molecules are described in detail. A detailed description of the double-pass Nd:YAG amplifier and the dye amplifiers is given with the pulse energies achieved in the visible, ultraviolet, and vacuum ultraviolet. The amplified visible pulses are shown to be of sub-picosecond duration and near transform limited. The instrument`s temporal response ({le}10 ps) is derived from an instrument limited measurement of the dissociation lifetime of methyl iodide at 266 nm. The methyl iodide experiment is used to discuss the various sources of noise and background signals that are intrinsic to this type of experiment. Non-time-resolved experiments measuring the branching ratio and kinetic energy distributions of products from the 193 nm photodissociation of cyclopentadiene and thiophene are presented. These studies were done using the molecular beam Photofragment Translational Spectroscopy (PTS) technique. The results from the cyclopentadiene experiment confirm that H atom elimination to yield the cyclopentadienyl radical is the dominant dissociation channel. A barrier of {ge}5 kcal/mol can be understood in terms of the delocalization of the radical electron of the cyclopentadienyl fragment. A concerted elimination yielding cyclopropene and acetylene was also observed and is proposed to occur via a bicyclo-[2.1.0]pent-2-ene intermediate. Two other channels, yielding acetylene plus the CH{sub 2}CHCH triplet carbene, and CH{sub 2} plus 1-buten-3-yne, are postulated to occur via ring opening. The implications of the experimental results for bulk thermal oxidation and pyrolysis models are discussed. The thiophene experiment shows six competing dissociation channels. The postulated intermediates for the various thiophene dissociation channels include bicyclo, ring opened, and possibly ring contracted forms.

  2. Message Passing for Dynamic Network Energy Management

    CERN Document Server

    Kraning, Matt; Lavaei, Javad; Boyd, Stephen

    2012-01-01

    We consider a network of devices, such as generators, fixed loads, deferrable loads, and storage devices, each with its own dynamic constraints and objective, connected by lossy capacitated lines. The problem is to minimize the total network objective subject to the device and line constraints, over a given time horizon. This is a large optimization problem, with variables for consumption or generation in each time period for each device. In this paper we develop a decentralized method for solving this problem. The method is iterative: At each step, each device exchanges simple messages with its neighbors in the network and then solves its own optimization problem, minimizing its own objective function, augmented by a term determined by the messages it has received. We show that this message passing method converges to a solution when the device objective and constraints are convex. The method is completely decentralized, and needs no global coordination other than synchronizing iterations; the problems to be...

  3. Beam-dynamics driven design of the LHeC energy-recovery linac

    Science.gov (United States)

    Pellegrini, Dario; Latina, Andrea; Schulte, Daniel; Bogacz, S. Alex

    2015-12-01

    The LHeC is envisioned as a natural upgrade of the LHC that aims at delivering an electron beam for collisions with the existing hadronic beams. The current baseline design for the electron facility consists of a multipass superconducting energy-recovery linac (ERL) operating in a continuous wave mode. The unprecedently high energy of the multipass ERL combined with a stringent emittance dilution budget poses new challenges for the beam optics. Here, we investigate the performances of a novel arc architecture based on a flexible momentum compaction lattice that mitigates the effects of synchrotron radiation while containing the bunch lengthening. Extensive beam-dynamics investigations have been performed with placet2, a recently developed tracking code for recirculating machines. They include the first end-to-end tracking and a simulation of the machine operation with a continuous beam. This paper briefly describes the Conceptual Design Report lattice, with an emphasis on possible and proposed improvements that emerged from the beam-dynamics studies. The detector bypass section has been integrated in the lattice, and its design choices are presented here. The stable operation of the ERL with a current up to ˜150 mA in the linacs has been validated in the presence of single- and multibunch wakefields, synchrotron radiation, and beam-beam effects.

  4. Review of Annual Global Mean Energy Budget and Radiative Force%全球年平均能流与辐射强迫研究进展

    Institute of Scientific and Technical Information of China (English)

    高凤玲; 华泽钊; 陶乐仁; 崔国民

    2013-01-01

    The concept of greenhouse effect was introduced and the state of research on greenhouse effect and global warming from the point view of annual global mean energy budget and radiative forcing were described, which concluded that anthropogenic factors were the major cause for global wanning. The problems existing in the study of global warming were pointed out as high uncertainties existing in downward long-wave radiation, surface latent energy flux and aerosol radiation force in the annual global mean energy budget. It suggested that the observation and study of stratospheric water vapor and spectral composition of solar radiation should be enhanced and measures of energy conservation and emission reduction should be taken.%介绍了温室效应的概念;从全球年平均能流及辐射强迫的角度概述了当前温室效应及全球变暖的研究现状,说明人为因素是造成全球变暖的主因.对目前全球变暖研究中存在的问题讨论指出,全球年平均能流中大气向下的长波辐射和地表潜热通量以及气溶胶的辐射强迫仍存在着较大的不确定性,应该加强对平流层水蒸汽及太阳活动光谱分析的观测和研究:须采取一定的节能减排措施.

  5. Evaluation of the Common Land Model (CoLM from the Perspective of Water and Energy Budget Simulation: Towards Inclusion in CMIP6

    Directory of Open Access Journals (Sweden)

    Chengwei Li

    2017-07-01

    Full Text Available Land surface models (LSMs are important tools for simulating energy, water and momentum transfer across the land–atmosphere interface. Many LSMs have been developed over the past 50 years, including the Common Land Model (CoLM, a LSM that has primarily been developed and maintained by Chinese researchers. CoLM has been adopted by several Chinese Earth System Models (GCMs that will participate in the Coupled Model Intercomparison Project Phase 6 (CMIP6. In this study, we evaluate the performance of CoLM with respect to simulating the water and energy budgets. We compare simulations using the latest version of CoLM (CoLM2014, the previous version of CoLM (CoLM2005 that was used in the Beijing Normal University Earth System Model (BNU-GCM for CMIP5, and the Community Land Model version 4.5 (CLM4.5 against global diagnostic data and observations. Our results demonstrate that CLM4.5 outperforms CoLM2005 and CoLM2014 in simulating runoff (R, although all three models overestimate runoff in northern Europe and underestimate runoff in North America and East Asia. Simulations of runoff and snow depth (SNDP are substantially improved in CoLM2014 relative to CoLM2005, particularly in the Northern Hemisphere. The simulated global energy budget is also substantially improved in CoLM2014 relative to CoLM2005. Simulations of sensible heat (SH based on CoLM2014 compare favorably to those based on CLM4.5, while root-mean-square errors (RMSEs in net surface radiation indicate that CoLM2014 (RMSE = 16.02 W m−2 outperforms both CoLM2005 (17.41 W m−2 and CLM4.5 (23.73 W m−2. Comparisons at regional scales show that all three models perform poorly in the Amazon region but perform relatively well over the central United States, Siberia and the Tibetan Plateau. Overall, CoLM2014 is improved relative to CoLM2005, and is comparable to CLM4.5 with respect to many aspects of the energy and water budgets. Our evaluation confirms CoLM2014 is suitable for inclusion in

  6. Is the Dynamics of Tracking Dark Energy Detectable?

    CERN Document Server

    Bassett, Bruce A; Cardoso, Antonio; Cortês, Marina; Fantaye, Yabebal; Hlozek, Renée; Kotze, Jacques; Okouma, Patrice

    2007-01-01

    We highlight the unexpected impact of nucleosynthesis and other early universe constraints on the detectability of tracking quintessence dynamics at late times, showing that such dynamics may well be invisible until the unveiling of the Stage-IV dark energy experiments (DUNE, JDEM, LSST, SKA). Nucleosynthesis forces |w'(0)| < 0.2 for the models we consider and strongly limits potential deviations from LCDM. Surprisingly, the standard CPL parametrisation, w(z) = w_0 + w_a z/(1+z), cannot match the nucleosynthesis bound for minimally coupled tracking scalar fields. Given that such models are arguably the best-motivated alternatives to a cosmological constant these results may significantly impact future cosmological survey design and imply that dark energy may well be dynamical even if we do not detect any dynamics in the next decade.

  7. The energy distribution structure and dynamic characteristics of energy release in electrostatic discharge process

    CERN Document Server

    Liu, Qingming; Zhang, Yunming

    2015-01-01

    The detail structure of energy output and the dynamic characteristics of electric spark discharge process have been studied to calculate the energy of electric spark induced plasma under different discharge condition accurately. A series of electric spark discharge experiments were conducted with the capacitor stored energy in the range of 10J 100J and 1000J respectively. And the resistance of wire, switch and plasma between electrodes were evaluated by different methods. An optimized method for electric resistance evaluation of the full discharge circuit, three poles switch and electric spark induced plasma during the discharge process was put forward. The electric energy consumed by wire, electric switch and electric spark induced plasma between electrodes were obtained by Joules law. The structure of energy distribution and the dynamic process of energy release during the capacitor discharge process have been studied. Experiments results showed that, with the increase of capacitor released energy, the dura...

  8. 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.

  9. Parton-Hadron-String Dynamics at relativistic collider energies

    Science.gov (United States)

    Bratkovskaya, E. L.; Cassing, W.; Konchakovski, V. P.; Linnyk, O.

    2011-04-01

    The novel Parton-Hadron-String Dynamics (PHSD) transport approach is applied to nucleus-nucleus collisions at RHIC energies with respect to differential hadronic spectra in comparison to available data. The PHSD approach is based on a dynamical quasiparticle model for partons (DQPM) matched to reproduce recent lattice-QCD results from the Wuppertal-Budapest group in thermodynamic equilibrium. The transition from partonic to hadronic degrees of freedom is described by covariant transition rates for the fusion of quark-antiquark pairs or three quarks (antiquarks), respectively, obeying flavor current-conservation, color neutrality as well as energy-momentum conservation. Our dynamical studies for heavy-ion collisions at relativistic collider energies are compared to earlier results from the Hadron-String Dynamics (HSD) approach - incorporating no explicit dynamical partonic phase - as well as to experimental data from the STAR, PHENIX, BRAHMS and PHOBOS Collaborations for Au + Au collisions at the top RHIC energy of √{s}=200 GeV. We find a reasonable reproduction of hadron rapidity distributions and transverse mass spectra and also a fair description of the elliptic flow of charged hadrons as a function of the centrality of the reaction and the transverse momentum p. Furthermore, an approximate quark-number scaling of the elliptic flow v of hadrons is observed in the PHSD results, too.

  10. Parton-Hadron-String Dynamics at relativistic collider energies

    Energy Technology Data Exchange (ETDEWEB)

    Bratkovskaya, E.L., E-mail: Elena.Bratkovskaya@th.physik.uni-frankfurt.d [Institut fuer Theoretische Physik, JWG Universitaet Frankfurt, D-60438 Frankfurt am Main (Germany); Frankfurt Institut for Advanced Studies, Frankfurt University, D-60438 Frankfurt-am-Main (Germany); Cassing, W.; Konchakovski, V.P. [Institut fuer Theoretische Physik, Universitaet Giessen, Heinrich-Buff-Ring 16, D-35392 Giessen (Germany); Linnyk, O. [Frankfurt Institut for Advanced Studies, Frankfurt University, D-60438 Frankfurt-am-Main (Germany)

    2011-04-15

    The novel Parton-Hadron-String Dynamics (PHSD) transport approach is applied to nucleus-nucleus collisions at RHIC energies with respect to differential hadronic spectra in comparison to available data. The PHSD approach is based on a dynamical quasiparticle model for partons (DQPM) matched to reproduce recent lattice-QCD results from the Wuppertal-Budapest group in thermodynamic equilibrium. The transition from partonic to hadronic degrees of freedom is described by covariant transition rates for the fusion of quark-antiquark pairs or three quarks (antiquarks), respectively, obeying flavor current-conservation, color neutrality as well as energy-momentum conservation. Our dynamical studies for heavy-ion collisions at relativistic collider energies are compared to earlier results from the Hadron-String Dynamics (HSD) approach - incorporating no explicit dynamical partonic phase - as well as to experimental data from the STAR, PHENIX, BRAHMS and PHOBOS Collaborations for Au + Au collisions at the top RHIC energy of {radical}(s)=200 GeV. We find a reasonable reproduction of hadron rapidity distributions and transverse mass spectra and also a fair description of the elliptic flow of charged hadrons as a function of the centrality of the reaction and the transverse momentum p{sub T}. Furthermore, an approximate quark-number scaling of the elliptic flow v{sub 2} of hadrons is observed in the PHSD results, too.

  11. State-to-state dynamics of molecular energy transfer

    Energy Technology Data Exchange (ETDEWEB)

    Gentry, W.R.; Giese, C.F. [Univ. of Minnesota, Minneapolis (United States)

    1993-12-01

    The goal of this research program is to elucidate the elementary dynamical mechanisms of vibrational and rotational energy transfer between molecules, at a quantum-state resolved level of detail. Molecular beam techniques are used to isolate individual molecular collisions, and to control the kinetic energy of collision. Lasers are used both to prepare specific quantum states prior to collision by stimulated-emission pumping (SEP), and to measure the distribution of quantum states in the collision products by laser-induced fluorescence (LIF). The results are interpreted in terms of dynamical models, which may be cast in a classical, semiclassical or quantum mechanical framework, as appropriate.

  12. Energy Efficiency Analysis for Dynamic Routing in Optical Transport Networks

    DEFF Research Database (Denmark)

    Vizcaíno, Jorge López; Ye, Yabin; Tafur Monroy, Idelfonso

    2012-01-01

    The energy efficiency in telecommunication networks is gaining more relevance as the Internet traffic is growing. The introduction of OFDM and dynamic operation opens new horizons in the operation of optical networks, improving the network flexibility and its efficiency. In this paper, we compare...... the performance in terms of energy efficiency of a flexible-grid OFDM-based solution with a fixed-grid WDM network in a dynamic scenario with time-varying connections. We highlight the benefits that the bandwidth elasticity and the flexibility of selecting different modulation formats can offer compared...

  13. Interannual variability in the surface energy budget over a large southern inland water: an analysis of two-year eddy covariance data

    Science.gov (United States)

    Zhang, Q.; Liu, H.

    2012-12-01

    Understanding how the surface energy budget and evaporation over inland waters respond to climate variability is important in fresh water management. Here we report long-term measurements of the surface energy budget using the eddy covariance method over a large inland southern water body of the Ross Barnett Reservoir, Mississippi, U.S.A. for 2008 and 2009. The two-year averaged incoming solar radiation (K↓), net radiation (Rn), sensible heat flux (H), latent heat flux (LE), and energy balance residual (ɛ) were 178.5, 110.6, 15.7, 83.7, and 11.3 W m-2, respectively. The annual cycle of Rn was followed by LE, with maximums occurring in the summer and minimums in the winter. H was small in the summer and large in the winter. The Bowen ratio shows that a relatively large portion of Rn was used to fuel evaporation in the warm season (from April to September) and to power H in the cool season (from October to March). The annual mean H and LE were 9.5% and 10.0% larger in 2008 than 2009, respectively. Most of the interannual variations primarily occurred in the cool season, which was partly due to the H and LE pulses that associated with large wind events caused by synoptic weather activities (e.g., cold front passages). These pulses approximately contributed to 50% of the annual H and 28% of the annual LE. Their interannual variations contributed to 77.8% of the interannual variations in H and 39.8% of those in LE. Compared with higher-latitude large lakes, this southern mid-latitude water body experienced larger evaporative water loss but smaller sensible heat loss into the atmosphere.

  14. Fluid Dynamical Consequences of Current and Stress-Energy Conservation

    Science.gov (United States)

    Scofield, Dillon; Huq, Pablo

    The dynamical consequences of fluid current conservation combined with the conservation of fluid stress-energy are used to develop the geometrodynamical theory of fluid flow (GTF). In the derivation of the GTF, we highlight the fact the continuity equation, equivalently the conservation of current density, implies the existence of the fluid dynamical vortex field. The vortex field transports part of the stress-energy; the other part of the stress-energy is transported by the fluid inertia field. Two channels of energy dissipation are determined by the GTF. One is an analog of the Joule heating found in electrodynamics. This follows from the conservation of stress-energy. The other dissipation channel arises from mechanisms leading to complex-valued constitutive parameters described in the electrodynamical analogy as due to a lossy medium. The dynamical consequences of the continuity equation, combined with the conservation of total stress-energy, then lead to a causal, covariant, theory of fluid flow, consistent with thermodynamics for all physically possible flow rates.

  15. Phase change energy storage for solar dynamic power systems

    Science.gov (United States)

    Chiaramonte, F. P.; Taylor, J. D.

    1992-01-01

    This paper presents the results of a transient computer simulation that was developed to study phase change energy storage techniques for Space Station Freedom (SSF) solar dynamic (SD) power systems. Such SD systems may be used in future growth SSF configurations. Two solar dynamic options are considered in this paper: Brayton and Rankine. Model elements consist of a single node receiver and concentrator, and takes into account overall heat engine efficiency and power distribution characteristics. The simulation not only computes the energy stored in the receiver phase change material (PCM), but also the amount of the PCM required for various combinations of load demands and power system mission constraints. For a solar dynamic power system in low earth orbit, the amount of stored PCM energy is calculated by balancing the solar energy input and the energy consumed by the loads corrected by an overall system efficiency. The model assumes an average 75 kW SD power system load profile which is connected to user loads via dedicated power distribution channels. The model then calculates the stored energy in the receiver and subsequently estimates the quantity of PCM necessary to meet peaking and contingency requirements. The model can also be used to conduct trade studies on the performance of SD power systems using different storage materials.

  16. A realistic dynamic blower energy consumption model for wastewater applications.

    Science.gov (United States)

    Amerlinck, Y; De Keyser, W; Urchegui, G; Nopens, I

    2016-10-01

    At wastewater treatment plants (WWTPs) aeration is the largest energy consumer. This high energy consumption requires an accurate assessment in view of plant optimization. Despite the ever increasing detail in process models, models for energy production still lack detail to enable a global optimization of WWTPs. A new dynamic model for a more accurate prediction of aeration energy costs in activated sludge systems, equipped with submerged air distributing diffusers (producing coarse or fine bubbles) connected via piping to blowers, has been developed and demonstrated. This paper addresses the model structure, its calibration and application to the WWTP of Mekolalde (Spain). The new model proved to give an accurate prediction of the real energy consumption by the blowers and captures the trends better than the constant average power consumption models currently being used. This enhanced prediction of energy peak demand, which dominates the price setting of energy, illustrates that the dynamic model is preferably used in multi-criteria optimization exercises for minimizing the energy consumption.

  17. Dynamic Energy Management System for a Smart Microgrid.

    Science.gov (United States)

    Venayagamoorthy, Ganesh Kumar; Sharma, Ratnesh K; Gautam, Prajwal K; Ahmadi, Afshin

    2016-08-01

    This paper presents the development of an intelligent dynamic energy management system (I-DEMS) for a smart microgrid. An evolutionary adaptive dynamic programming and reinforcement learning framework is introduced for evolving the I-DEMS online. The I-DEMS is an optimal or near-optimal DEMS capable of performing grid-connected and islanded microgrid operations. The primary sources of energy are sustainable, green, and environmentally friendly renewable energy systems (RESs), e.g., wind and solar; however, these forms of energy are uncertain and nondispatchable. Backup battery energy storage and thermal generation were used to overcome these challenges. Using the I-DEMS to schedule dispatches allowed the RESs and energy storage devices to be utilized to their maximum in order to supply the critical load at all times. Based on the microgrid's system states, the I-DEMS generates energy dispatch control signals, while a forward-looking network evaluates the dispatched control signals over time. Typical results are presented for varying generation and load profiles, and the performance of I-DEMS is compared with that of a decision tree approach-based DEMS (D-DEMS). The robust performance of the I-DEMS was illustrated by examining microgrid operations under different battery energy storage conditions.

  18. Dynamic energy management employing renewable energy sources in IP over DWDM networks

    DEFF Research Database (Denmark)

    Chen, Xin; Phillips, Chris; Wang, Jiayuan

    2013-01-01

    The continued growth of energy consumption has been one of the main constraints for the development of the Internet. The increasing emissions of greenhouse gases associated with electricity generation also raise public concern for the environment. In this paper, we propose a dynamic energy...... management framework employing renewable energy sources in IP over DWDM core networks. The main concept is to combine infrastructure sleeping and virtual router migration to improve the network energy efficiency. By using the energy source information provided by the smart grid, the nodes that are powered...

  19. A proposal to the dissipated energy budget in the auroral ionosphere at the substorm recovery phase: Challenge from thermospheric wind variations in the pulsating aurora

    Science.gov (United States)

    Oyama, S. I.; Hosokawa, K.; Miyoshi, Y.; Shiokawa, K.; Kurihara, J.; Tsuda, T. T.; Watkins, B. J.

    2014-12-01

    Pulsating aurora is a typical phenomenon of the recovery phase of magnetic substorm and is frequently observed in the morning sector. The widely accepted generation mechanism of pulsations in precipitating electrons is related to wave-particle interactions around the equatorial plane in the magnetospheric tail. This mechanism is completely different from the discrete-arc case, which generates high-energy auroral electrons by the inverted-V type potential structure in the magnetospheric acceleration region. This potential structure induces the perpendicular electric field. The electric field is mapped down to the ionosphere, and enhances the Pedersen current as the ionospheric closure current. Since the perpendicular electric field directly relates to the Joule heating rate and the Lorentz force, thermal and kinetic energies in the thermosphere are locally increased in the vicinity of the arc rather than the inside, resulting in wind variations in the thermosphere. However, this scenario cannot be simply applied to the pulsating-auroral case because of the completely different mechanism of the auroral-electron generation, and we have believed that large energies are not dissipated in the pulsating aurora and there should be no obvious wind variations in the thermosphere. However, we found thermospheric-wind variations in the pulsating aurora during simultaneous observations with a Fabry-Perot Interferometer (557.7 nm), several cameras, and incoherent-scatter radars. This is a significantly important finding in evaluating our understanding of the energy budget in the substorm recovery phase. As mentioned above, the Joule heating process and the Lorentz force play important roles for thermospheric-wind variations. While the both cases need enhancements of the perpendicular electric field, we well know that a typical level of the convection electric field is too low to generate the wind variations in a same level as the observed in the pulsating aurora. Thus the

  20. Global Carbon Budget 2016

    Science.gov (United States)

    Le Quéré, Corinne; Andrew, Robbie M.; Canadell, Josep G.; Sitch, Stephen; Korsbakken, Jan Ivar; Peters, Glen P.; Manning, Andrew C.; Boden, Thomas A.; Tans, Pieter P.; Houghton, Richard A.; Keeling, Ralph F.; Alin, Simone; Andrews, Oliver D.; Anthoni, Peter; Barbero, Leticia; Bopp, Laurent; Chevallier, Frédéric; Chini, Louise P.; Ciais, Philippe; Currie, Kim; Delire, Christine; Doney, Scott C.; Friedlingstein, Pierre; Gkritzalis, Thanos; Harris, Ian; Hauck, Judith; Haverd, Vanessa; Hoppema, Mario; Klein Goldewijk, Kees; Jain, Atul K.; Kato, Etsushi; Körtzinger, Arne; Landschützer, Peter; Lefèvre, Nathalie; Lenton, Andrew; Lienert, Sebastian; Lombardozzi, Danica; Melton, Joe R.; Metzl, Nicolas; Millero, Frank; Monteiro, Pedro M. S.; Munro, David R.; Nabel, Julia E. M. S.; Nakaoka, Shin-ichiro; O'Brien, Kevin; Olsen, Are; Omar, Abdirahman M.; Ono, Tsuneo; Pierrot, Denis; Poulter, Benjamin; Rödenbeck, Christian; Salisbury, Joe; Schuster, Ute; Schwinger, Jörg; Séférian, Roland; Skjelvan, Ingunn; Stocker, Benjamin D.; Sutton, Adrienne J.; Takahashi, Taro; Tian, Hanqin; Tilbrook, Bronte; van der Laan-Luijkx, Ingrid T.; van der Werf, Guido R.; Viovy, Nicolas; Walker, Anthony P.; Wiltshire, Andrew J.; Zaehle, Sönke

    2016-11-01

    Accurate assessment of anthropogenic carbon dioxide (CO2) emissions and their redistribution among the atmosphere, ocean, and terrestrial biosphere - the "global carbon budget" - is important to better understand the global carbon cycle, support the development of climate policies, and project future climate change. Here we describe data sets and methodology to quantify all major components of the global carbon budget, including their uncertainties, based on the combination of a range of data, algorithms, statistics, and model estimates and their interpretation by a broad scientific community. We discuss changes compared to previous estimates and consistency within and among components, alongside methodology and data limitations. CO2 emissions from fossil fuels and industry (EFF) are based on energy statistics and cement production data, respectively, while emissions from land-use change (ELUC), mainly deforestation, are based on combined evidence from land-cover change data, fire activity associated with deforestation, and models. The global atmospheric CO2 concentration is measured directly and its rate of growth (GATM) is computed from the annual changes in concentration. The mean ocean CO2 sink (SOCEAN) is based on observations from the 1990s, while the annual anomalies and trends are estimated with ocean models. The variability in SOCEAN is evaluated with data products based on surveys of ocean CO2 measurements. The global residual terrestrial CO2 sink (SLAND) is estimated by the difference of the other terms of the global carbon budget and compared to results of independent dynamic global vegetation models. We compare the mean land and ocean fluxes and their variability to estimates from three atmospheric inverse methods for three broad latitude bands. All uncertainties are reported as ±1σ, reflecting the current capacity to characterise the annual estimates of each component of the global carbon budget. For the last decade available (2006-2015), EFF was 9

  1. Dynamics of CO2-exchange and C-budgets due to soil erosion: Insights from a 4 years observation period

    Science.gov (United States)

    Hoffmann, Mathias; Albiac Borraz, Elisa; Garcia Alba, Juana; Augustin, Jürgen; Sommer, Michael

    2015-04-01

    Agriculture in the hummocky ground moraine landscape of NE-Germany is characterized by an increase in energy crop cultivation, like maize or sorghum. Both enhance lateral C fluxes by erosion and induce feedbacks on C dynamics of agroecosystems as a result of reduced wintertime plant cover and vigorous crop growth during summer. However, the actual impact of these phenomena on the CO2-sink/-source function of agricultural landscapes, is still not clear. Therefore, the interdisciplinary project "CarboZALF" was established in Dedelow/Prenzlau (NE-Germany) in 2009. Within the field experiment CarboZALF-D, CO2 fluxes for the soil-plant systems were monitored, covering typical landscape relevant soil states in respect to erosion and deposition, like Calcic Cutanic Luvisol and Endogleyic Colluvic Regosol. Automated chamber systems, each consisting of four transparent chambers (2.5 m height, basal area 2.25 m2), were placed along gradients at both measurement sites. Monitored CO2 fluxes were gap-filled on a high-temporal resolution by modelling ecosystem respiration (Reco), gross primary productivity (GPP) and net ecosystem exchange (NEE) based on parallel and continuous measurements of the CO2 exchange, soil and air temperatures as well as photosynthetic active radiation (PAR). Gap-filling was e.g. needed in case of chamber malfunctions and abrupt disturbances by farming practice. The monitored crop rotation was corn-winter wheat (2 a), sorghum-winter triticale and alfalfa (1.5 a). In our presentation we would like to show insights from a 4 years observation period, with prounounced differences between the eroded and the colluvial soil: The Endogleyic Colluvic Regosol showed higher flux rates for Reco, GPP and NEE compared to the Calcic Cutanic Luvisol. Site-specific NEE and C-balances were positively related to soil C-stocks as well as biomass production, and generated a minor C-sink in case of the Calcic Cutanic Luvisol and a highly variable C-source in case of the

  2. Energetic and dynamic: how mitochondria meet neuronal energy demands.

    Directory of Open Access Journals (Sweden)

    Dzhamilja Safiulina

    2013-12-01

    Full Text Available Mitochondria are the power houses of the cell, but unlike the static structures portrayed in textbooks, they are dynamic organelles that move about the cell to deliver energy to locations in need. These organelles fuse with each other then split apart; some appear anchored and others more free to move around, and when damaged they are engulfed by autophagosomes. Together, these processes-mitochondrial trafficking, fusion and fission, and mitophagy-are best described by the term "mitochondrial dynamics". The molecular machineries behind these events are relatively well known yet the precise dynamics in neurons remains under debate. Neurons pose a peculiar logistical challenge to mitochondria; how do these energy suppliers manage to traffic down long axons to deliver the requisite energy supply to distant parts of the cell? To date, the majority of neuronal mitochondrial dynamics studies have used cultured neurons, Drosophila larvae, zebrafish embryos, with occasional experiments in resting mouse nerves. However, a new study in this issue of PLOS Biology from Marija Sajic and colleagues provides an in vivo look at mitochondrial dynamics along resting and electrically active neurons of live anaesthetized mice.

  3. Binary cluster collision dynamics and minimum energy conformations

    Energy Technology Data Exchange (ETDEWEB)

    Muñoz, Francisco [Max Planck Institute of Microstructure Physics, Weinberg 2, 06120 Halle (Germany); Departamento de Física, Facultad de Ciencias, Universidad de Chile, Santiago (Chile); Centro para el Desarrollo de la Nanociencia y Nanotecnología, CEDENNA, Avenida Ecuador 3493, Santiago (Chile); Rogan, José; Valdivia, J.A. [Departamento de Física, Facultad de Ciencias, Universidad de Chile, Santiago (Chile); Centro para el Desarrollo de la Nanociencia y Nanotecnología, CEDENNA, Avenida Ecuador 3493, Santiago (Chile); Varas, A. [Departamento de Física, Facultad de Ciencias, Universidad de Chile, Santiago (Chile); Nano-Bio Spectroscopy Group, ETSF Scientific Development Centre, Departamento de Física de Materiales, Universidad del País Vasco UPV/EHU, Av. Tolosa 72, E-20018 San Sebastián (Spain); Kiwi, Miguel, E-mail: m.kiwi.t@gmail.com [Departamento de Física, Facultad de Ciencias, Universidad de Chile, Santiago (Chile); Centro para el Desarrollo de la Nanociencia y Nanotecnología, CEDENNA, Avenida Ecuador 3493, Santiago (Chile)

    2013-10-15

    The collision dynamics of one Ag or Cu atom impinging on a Au{sub 12} cluster is investigated by means of DFT molecular dynamics. Our results show that the experimentally confirmed 2D to 3D transition of Au{sub 12}→Au{sub 13} is mostly preserved by the resulting planar Au{sub 12}Ag and Au{sub 12}Cu minimum energy clusters, which is quite remarkable in view of the excess energy, well larger than the 2D–3D potential barrier height. The process is accompanied by a large s−d hybridization and charge transfer from Au to Ag or Cu. The dynamics of the collision process mainly yields fusion of projectile and target, however scattering and cluster fragmentation also occur for large energies and large impact parameters. While Ag projectiles favor fragmentation, Cu favors scattering due to its smaller mass. The projectile size does not play a major role in favoring the fragmentation or scattering channels. By comparing our collision results with those obtained by an unbiased minimum energy search of 4483 Au{sub 12}Ag and 4483 Au{sub 12}Cu configurations obtained phenomenologically, we find that there is an extra bonus: without increase of computer time collisions yield the planar lower energy structures that are not feasible to obtain using semi-classical potentials. In fact, we conclude that phenomenological potentials do not even provide adequate seeds for the search of global energy minima for planar structures. Since the fabrication of nanoclusters is mainly achieved by synthesis or laser ablation, the set of local minima configurations we provide here, and their distribution as a function of energy, are more relevant than the global minimum to analyze experimental results obtained at finite temperatures, and is consistent with the dynamical coexistence of 2D and 3D liquid Au clusters conformations obtained previously.

  4. THE DYNAMICS AND TRACTION ENERGY METRICS LOCOMOTIVE VL40

    Directory of Open Access Journals (Sweden)

    S. V. Pylypenko

    2008-03-01

    Full Text Available In the article the results of dynamic running and traction-energy tests of the electric locomotive VL40U are presented. In accordance with the test results a conclusion about the suitability of electric locomotive of such a type for operation with trains containing up to 15 passenger coaches inclusive is made.

  5. Towards improved understanding of cloud influence on polar surface energy budgets using CloudSat and CALIPSO observations

    Science.gov (United States)

    Kay, J. E.; L'Ecuyer, T. S.; McIlhattan, E.; Chepfer, H.; Morrison, A.

    2015-12-01

    The spaceborne radar CloudSat and the spaceborne lidar platform Cloud-Aerosol Lidar and Infrared Pathfinder Satellite Observation (CALIPSO) have provided nearly a decade of groundbreaking observations of polar cloud and precipitation processes. Specifically relevant to this AGU session, the CloudSat 2B-FLXHR-LIDAR product (hereafter, 2BFLX) is an observationally constrained radiative flux and heating rate calculation that leverages constraints from A-train observations, including CloudSat+CALIPSO. The surface radiative fluxes calculated within 2BFLX represent an important advance because unlike top-of-atmosphere (TOA) fluxes, surface radiative fluxes cannot be directly measured by satellite, yet directly impact surface heating, sea ice melt, and ice sheet mass balance. In this presentation, we will highlight the influence of supercooled liquid on polar surface radiation budgets constrained within 2BFLX data. We will also use 2BFLX data in concert with the fully attenuated signal and cloud phase information from CALIPSO as an observational constraint on polar cloud-climate feedbacks in the Community Earth System Model (CESM).

  6. Surface radiation budget in the Clouds and the Earth's Radiant Energy System (CERES) effort and in the Global Energy and Water Cycle Experiment (GEWEX)

    Science.gov (United States)

    Charlock, Thomas P.; Smith, G. L.; Rose, Fred G.

    1990-01-01

    The surface radiation budget (SRB) and the atmospheric radiative flux divergence (ARD) are vital components of the weather and climate system. The importance of radiation in a complex international scientific endeavor, the GEWEX of the World Climate Research Programme is explained. The radiative transfer techniques and satellite instrumentation that will be used to retrieve the SRB and ARD later in this decade with the CERES are discussed; CERES is a component of the Earth Observing System satellite program. Examples of consistent SRB and ARD retrievals made with Nimbus-7 and International Satellite Cloud Climatology Project data from July 1983 are presented.

  7. The Atmospheric Energy Budget and Large-Scale Precipitation Efficiency of Convective Systems during TOGA COARE, GATE, SCSMEX, and ARM: Cloud-Resolving Model Simulations.

    Science.gov (United States)

    Tao, W.-K.; Johnson, D.; Shie, C.-L.; Simpson, J.

    2004-10-01

    A two-dimensional version of the Goddard Cumulus Ensemble (GCE) model is used to simulate convective systems that developed in various geographic locations (east Atlantic, west Pacific, South China Sea, and Great Plains in the United States). Observed large-scale advective tendencies for potential temperature, water vapor mixing ratio, and horizontal momentum derived from field campaigns are used as the main forcing. The atmospheric temperature and water vapor budgets from the model results show that the two largest terms are net condensation (heating/drying) and imposed large-scale forcing (cooling/moistening) for tropical oceanic cases though not for midlatitude continental cases. These two terms are opposite in sign, however, and are not the dominant terms in the moist static energy budget.The balance between net radiation, surface latent heat flux, and net condensational heating vary in these tropical cases, however. For cloud systems that developed over the South China Sea and eastern Atlantic, net radiation (cooling) is not negligible in the temperature budget; it is as large as 20% of the net condensation. However, shortwave heating and longwave cooling are in balance with each other for cloud systems over the west Pacific region such that the net radiation is very small. This is due to the thick anvil clouds simulated in the cloud systems over the Pacific region. The large-scale advection of moist static energy is negative, as a result of a larger absolute value of large-scale advection of sensible heat (cooling) compared to large-scale latent heat (moistening) advection in the Pacific and Atlantic cases. For three cloud systems that developed over a midlatitude continent, the net radiation and sensible and latent heat fluxes play a much more important role. This means that the accurate measurement of surface fluxes and radiation is crucial for simulating these midlatitude cases.The results showed that large-scale mean (multiday) precipitation efficiency

  8. Influence of sludge digestion on the energy budgets of sewage treatment plants; Einfluss der Schlammfaulung auf die Energiebilanz von Klaeranlagen

    Energy Technology Data Exchange (ETDEWEB)

    Kapp, H. [Fachhochschule Biberach an der Riss (Germany). Hochschule fuer Bauwesen

    1998-12-31

    Part of the energy potential of sewage is harnessed in anaerobic sludge digestion in such a way that the energy contained in the reduced carbon compounds is converted into methane, which is then used as a fuel or to generate power. The anaerobic process consumes hardly any energy at all, in other words, the accruing amount of waste heat is negligible, unlike the aerobic reaction. A more or less large proportion of the energy requirement for, especially, aerobic degradation processes can thus be covered using the high-grade energy obtained during sludge digestion. (orig.) [Deutsch] Das im Abwasser enthaltene Energiepotential wird (teilweise) bei der anaeroben Schlammfaulung in der Weise genutzt, dass eine Umwandlung der in den reduzierten C-Verbindungen enthaltenen Energie in Methan erfolgt, welches schliesslich fuer die Kraft- bzw. Stromerzeugung zur Verfuegung steht. Der anaerobe Prozess selbst verbraucht nur eine nahezu unbedeutende Energiemenge, d.h. die Abwaermemenge ist im Verhaeltnis zu jener bei der Aerobreaktion praktisch vernachlaessigbar. Damit ergibt sich die Moeglichkeit, einen mehr oder weniger grossen Anteil des, vor allem fuer die aeroben Abbauprozesse, erforderlichen Energieaufwandes durch die bei der Schlammfaulung gewonnene und hochwertig verwertbare Energie abzudecken. (orig.)

  9. The impact of Arctic sea ice on the Arctic energy budget and on the climate of the Northern mid-latitudes

    Energy Technology Data Exchange (ETDEWEB)

    Semmler, Tido [Alfred Wegener Institute for Polar and Marine Research, Bremerhaven (Germany); Met Eireann, Glasnevin Hill, Dublin 9 (Ireland); McGrath, Ray [Met Eireann, Glasnevin Hill, Dublin 9 (Ireland); Wang, Shiyu [Swedish Meteorological and Hydrological Institute, Norrkoeping (Sweden); Met Eireann, Glasnevin Hill, Dublin 9 (Ireland)

    2012-12-15

    The atmospheric general circulation model EC-EARTH-IFS has been applied to investigate the influence of both a reduced and a removed Arctic sea ice cover on the Arctic energy budget and on the climate of the Northern mid-latitudes. Three 40-year simulations driven by original and modified ERA-40 sea surface temperatures and sea ice concentrations have been performed at T255L62 resolution, corresponding to 79 km horizontal resolution. Simulated changes between sensitivity and reference experiments are most pronounced over the Arctic itself where the reduced or removed sea ice leads to strongly increased upward heat and longwave radiation fluxes and precipitation in winter. In summer, the most pronounced change is the stronger absorption of shortwave radiation which is enhanced by optically thinner clouds. Averaged over the year and over the area north of 70 N, the negative energy imbalance at the top of the atmosphere decreases by about 10 W/m{sup 2} in both sensitivity experiments. The energy transport across 70 N is reduced. Changes are not restricted to the Arctic. Less extreme cold events and less precipitation are simulated in sub-Arctic and Northern mid-latitude regions in winter. (orig.)

  10. A Case Study of the Impacts of Dust Aerosols on Surface Atmospheric Variables and Energy Budgets in a Semi-Arid Region of China

    Institute of Scientific and Technical Information of China (English)

    LING Xiao-Lu; GUO Wei-Dong; ZHANG Le; ZHANG Ren-Jian

    2010-01-01

    The authors present a case study investigatingthe impacts of dust aerosols on surface atmospheric variables and energy budgets in a semi-arid region of China.Enhanced observational meteorological data, radiative fluxes, near-surface heat fluxes, and concentrations of dust aerosols were collected from Tongyu station, one of the reference sites of the International Coordinated Energy and Water Cycle Observations Project (CEOP), during a typical dust storm event in June 2006. A comprehensive analysis of these data show that in this semi-arid area, higher wind velocities and a continuously reduced air pressure were identified during the dust storm period.Dust storm events are usually associated with low relative humidity weather conditions, which result in low latent heat flux values. Dust aerosols suspended in the air decrease the net radiation, mainly by reducing the direct solar radiation reaching the land surface. This reduction in net radiation results in a decrease in soil temperatures at a depth of 2 cm. The combination of increased air temperature and decreased soil temperature strengthens the energy exchange of the atmosphere-earth system, increasing the surface sensible heat flux. After the dust storm event,the atmosphere was dominated by higher pressures and was relatively wet and cold. Net radiation and latent heat flux show an evident increase, while the surface sensible heat flux shows a clear decrease.

  11. Energy budgets of the Chinese green lacewing (Neuroptera: Chrysopidae) and its potential for biological control of the cotton aphid (Homoptera: Aphididae)

    Institute of Scientific and Technical Information of China (English)

    FENG GAO; XIANG-HUI LIU; FENG GE

    2007-01-01

    Energy budgets of larval stages of the Chinese green lacewing, Chrysopa sinica (Tjeder) (Neuroptera: Chrysopidae) were determined under laboratory conditions at photoperiod of 14:10 L:D, 27±1℃ and 75%±2% RH. The energy used as ingestion,assimilation, respiration, productivity and feces was constructed for each developmental stage. In addition, under these experimental conditions, the potential of C.sinica as a biological control agent was evaluated according to the ingestion by this predator and the energy content of cotton aphid, Aphis gossypii (Glover) (Homoptera: Aphididae). The larval stage of C. sinica was able to consume 1281.4 1-day-old aphids, 1018.7 2-day-old aphids,626.9 3-day-old aphids, 393.5 4-day-old aphids, 312.1 5-day-old aphids or 203.5 9-day-old aphids, respectively. No significant difference was detected between the estimated number of aphids consumed by the lacewings using energetic methods and the actual number of aphids consumed by the lacewings in this experiment. Our results showed that C. sinica is an important natural enemy of the cotton aphid, and energetic methods are very useful to quantify biological control efficacy of natural enemies.

  12. Energy conservation in molecular dynamics simulations of classical systems.

    Science.gov (United States)

    Toxvaerd, Søren; Heilmann, Ole J; Dyre, Jeppe C

    2012-06-14

    Classical Newtonian dynamics is analytic and the energy of an isolated system is conserved. The energy of such a system, obtained by the discrete "Verlet" algorithm commonly used in molecular dynamics simulations, fluctuates but is conserved in the mean. This is explained by the existence of a "shadow Hamiltonian" H [S. Toxvaerd, Phys. Rev. E 50, 2271 (1994)], i.e., a Hamiltonian close to the original H with the property that the discrete positions of the Verlet algorithm for H lie on the analytic trajectories of H. The shadow Hamiltonian can be obtained from H by an asymptotic expansion in the time step length. Here we use the first non-trivial term in this expansion to obtain an improved estimate of the discrete values of the energy. The investigation is performed for a representative system with Lennard-Jones pair interactions. The simulations show that inclusion of this term reduces the standard deviation of the energy fluctuations by a factor of 100 for typical values of the time step length. Simulations further show that the energy is conserved for at least one hundred million time steps provided the potential and its first four derivatives are continuous at the cutoff. Finally, we show analytically as well as numerically that energy conservation is not sensitive to round-off errors.

  13. Regional Dynamic Simulation Modeling and Analysis of Integrated Energy Futures

    Energy Technology Data Exchange (ETDEWEB)

    MALCZYNSKI, LEONARD A.; BEYELER, WALTER E.; CONRAD, STEPHEN H.; HARRIS, DAVID B; REXROTH, PAUL E.; BAKER, ARNOLD B.

    2002-11-01

    The Global Energy Futures Model (GEFM) is a demand-based, gross domestic product (GDP)-driven, dynamic simulation tool that provides an integrated framework to model key aspects of energy, nuclear-materials storage and disposition, environmental effluents from fossil and non fossil energy and global nuclear-materials management. Based entirely on public source data, it links oil, natural gas, coal, nuclear and renewable energy dynamically to greenhouse-gas emissions and 12 other measures of environmental impact. It includes historical data from 1990 to 2000, is benchmarked to the DOE/EIA/IEO 2001 [5] Reference Case for 2000 to 2020, and extrapolates energy demand through the year 2050. The GEFM is globally integrated, and breaks out five regions of the world: United States of America (USA), the Peoples Republic of China (China), the former Soviet Union (FSU), the Organization for Economic Cooperation and Development (OECD) nations excluding the USA (other industrialized countries), and the rest of the world (ROW) (essentially the developing world). The GEFM allows the user to examine a very wide range of ''what if'' scenarios through 2050 and to view the potential effects across widely dispersed, but interrelated areas. The authors believe that this high-level learning tool will help to stimulate public policy debate on energy, environment, economic and national security issues.

  14. Energy prices, technological knowledge and green energy innovation. A dynamic panel analysis of patent counts

    Energy Technology Data Exchange (ETDEWEB)

    Kruse, Juergen; Wetzel, Heike [Koeln Univ. (Germany). Dept. of Economics; Koeln Univ. (Germany). Energiewirtschaftliches Inst.

    2014-07-15

    We examine the effect of energy prices and technological knowledge on innovation in green energy technologies. In doing so, we consider both demand-pull effects, which induce innovative activity by increasing the expected value of innovations, and technology-push effects, which drive innovative activity by extending the technological capability of an economy. Our analysis is conducted using patent data from the European Patent Office on a panel of 26 OECD countries over the period 1978-2009. Utilizing a dynamic count data model for panel data, we analyze 11 distinct green energy technologies. Our results indicate that the existing knowledge stock is a significant driver of green energy innovation for all technologies. Furthermore, the results suggest that energy prices have a positive impact on innovation for some but not all technologies and that the e.ect of energy prices and technological knowledge on green energy innovation becomes more pronounced after the Kyoto protocol agreement in 1997.

  15. Dynamically controlled energy dissipation for fast magnetic vortex switching

    Science.gov (United States)

    Badea, R.; Berezovsky, J.

    2017-09-01

    Manipulation of vortex states in magnetic media provides new routes towards information storage and processing technology. The typical slow relaxation times (˜100 ns) of magnetic vortex dynamics may present an obstacle to the realization of these applications. Here, we investigate how a vortex state in a ferromagnetic microdisk can be manipulated in a way that translates the vortex core while enhancing energy dissipation to rapidly damp the vortex dynamics. We use time-resolved differential magneto-optical Kerr effect microscopy to measure the motion of the vortex core in response to applied magnetic fields. We first map out how the vortex core becomes sequentially trapped by pinning sites as it translates across the disk. After applying a fast magnetic field step to translate the vortex from one pinning site to another, we observe long-lived dynamics of the vortex as it settles to the new equilibrium. We then demonstrate how the addition of a short (magnetic field pulse can induce additional energy dissipation, strongly damping the long-lived dynamics. A model of the vortex dynamics using the Thiele equation of motion explains the mechanism behind this effect.

  16. Pseudospectral Gaussian quantum dynamics: Efficient sampling of potential energy surfaces

    Science.gov (United States)

    Heaps, Charles W.; Mazziotti, David A.

    2016-04-01

    Trajectory-based Gaussian basis sets have been tremendously successful in describing high-dimensional quantum molecular dynamics. In this paper, we introduce a pseudospectral Gaussian-based method that achieves accurate quantum dynamics using efficient, real-space sampling of the time-dependent basis set. As in other Gaussian basis methods, we begin with a basis set expansion using time-dependent Gaussian basis functions guided by classical mechanics. Unlike other Gaussian methods but characteristic of the pseudospectral and collocation methods, the basis set is tested with N Dirac delta functions, where N is the number of basis functions, rather than using the basis function as test functions. As a result, the integration for matrix elements is reduced to function evaluation. Pseudospectral Gaussian dynamics only requires O ( N ) potential energy calculations, in contrast to O ( N 2 ) evaluations in a variational calculation. The classical trajectories allow small basis sets to sample high-dimensional potentials. Applications are made to diatomic oscillations in a Morse potential and a generalized version of the Henon-Heiles potential in two, four, and six dimensions. Comparisons are drawn to full analytical evaluation of potential energy integrals (variational) and the bra-ket averaged Taylor (BAT) expansion, an O ( N ) approximation used in Gaussian-based dynamics. In all cases, the pseudospectral Gaussian method is competitive with full variational calculations that require a global, analytical, and integrable potential energy surface. Additionally, the BAT breaks down when quantum mechanical coherence is particularly strong (i.e., barrier reflection in the Morse oscillator). The ability to obtain variational accuracy using only the potential energy at discrete points makes the pseudospectral Gaussian method a promising avenue for on-the-fly dynamics, where electronic structure calculations become computationally significant.

  17. Automated Budget System

    Data.gov (United States)

    Department of Transportation — The Automated Budget System (ABS) automates management and planning of the Mike Monroney Aeronautical Center (MMAC) budget by providing enhanced capability to plan,...

  18. Dynamic facades, the smart way of meeting the energy requirements

    DEFF Research Database (Denmark)

    Johnsen, Kjeld; Winther, Frederik Vilbrad

    2015-01-01

    The paper describes an innovative dynamic façade system, developed in cooperation between two industrial companies, the Danish Building Research Institute and Aalborg University, Den¬mark. The system, named Energy Frames, is a newly developed industrially produced façade system based on the exper......The paper describes an innovative dynamic façade system, developed in cooperation between two industrial companies, the Danish Building Research Institute and Aalborg University, Den¬mark. The system, named Energy Frames, is a newly developed industrially produced façade system based...... on the experiences of a number of specially designed solutions for significant individual buildings all over the world. As the demand for energy efficiency of buildings grows throughout Europe, the necessity of developing energy efficient building envelope solutions increases, whilst maintaining acceptable indoor...... climate conditions. The dynamic façades play an important role in this development as it optimizes the interaction with the external environment in close correlation with the demand from the building and the users....

  19. Bioenergetic Limitations on Slow Microbial Growth in the Subsurface: What is the Burden of Maintenance on the Overall Energy Budget?

    Science.gov (United States)

    Smeaton, C. M.; Bajracharya, B. M.; Ridenour, C.; Van Cappellen, P.

    2014-12-01

    In low energy environments such as the subsurface, the minimum energy required to maintain cellular integrity and function (maintenance energy) may represent a significant fraction of the total energy available to microbial communities. However, traditional kinetic and thermodynamic models incorporating key microbial processes are often developed using data collected in nutrient rich growth media. In this study, slow microbial growth in the subsurface was simulated using a flow through bioreactor system in experiments designed to determine the maintenance energy requirement of the model subsurface bacterium Shewanella oneidensis. An existing bioreactor system (Applikon EZ-control®, 2.4 L) was modified to include a biomass retention filtration unit (retentostat) resulting in biomass accumulation over time. An artificial low-nutrient groundwater medium was optimized for slow S. oneidensis growth and was supplied and removed from the reactor at flow rates on the order of 1 mL min-1 with a dilution rate of 0.025 h-1. The retentostat was run under electron donor limited conditions with nitrate, a common groundwater contaminant, supplied at 0.025 mM h-1 and lactate supplied in excess at 0.125 mM h-1. Respiratory ammonification of nitrate by S. oneidensis and cell growth was monitored over time (40 days) and compared to parallel incubations in batch reactors. Initial rates of ammonification were similar in the bioreactor and batch reactors, however, optical density and ATP measurements showed slow yet increasing microbial growth over time (generation time = 17 days) in the retentostat. In contrast, cells in the batch reactors did not grow significantly and died within 2 weeks of inoculation. A maintenance energy demand was estimated (2.5 kJ C-mol biomass h-1) by fitting the biomass production rates to the van Verseveld equation. The low maintenance energy demand of S. oneidensis as compared to typical maintenance energies reported in the literature (>10 kJ C-mol biomass

  20. Detecting small-scale spatial heterogeneity and temporal dynamics of soil organic carbon (SOC) stocks: a comparison between automatic chamber-derived C budgets and repeated soil inventories

    Science.gov (United States)

    Hoffmann, Mathias; Jurisch, Nicole; Garcia Alba, Juana; Albiac Borraz, Elisa; Schmidt, Marten; Huth, Vytas; Rogasik, Helmut; Rieckh, Helene; Verch, Gernot; Sommer, Michael; Augustin, Jürgen

    2017-03-01

    Carbon (C) sequestration in soils plays a key role in the global C cycle. It is therefore crucial to adequately monitor dynamics in soil organic carbon (ΔSOC) stocks when aiming to reveal underlying processes and potential drivers. However, small-scale spatial (10-30 m) and temporal changes in SOC stocks, particularly pronounced in arable lands, are hard to assess. The main reasons for this are limitations of the well-established methods. On the one hand, repeated soil inventories, often used in long-term field trials, reveal spatial patterns and trends in ΔSOC but require a longer observation period and a sufficient number of repetitions. On the other hand, eddy covariance measurements of C fluxes towards a complete C budget of the soil-plant-atmosphere system may help to obtain temporal ΔSOC patterns but lack small-scale spatial resolution. To overcome these limitations, this study presents a reliable method to detect both short-term temporal dynamics as well as small-scale spatial differences of ΔSOC using measurements of the net ecosystem carbon balance (NECB) as a proxy. To estimate the NECB, a combination of automatic chamber (AC) measurements of CO2 exchange and empirically modeled aboveground biomass development (NPPshoot) were used. To verify our method, results were compared with ΔSOC observed by soil resampling. Soil resampling and AC measurements were performed from 2010 to 2014 at a colluvial depression located in the hummocky ground moraine landscape of northeastern Germany. The measurement site is characterized by a variable groundwater level (GWL) and pronounced small-scale spatial heterogeneity regarding SOC and nitrogen (Nt) stocks. Tendencies and magnitude of ΔSOC values derived by AC measurements and repeated soil inventories corresponded well. The period of maximum plant growth was identified as being most important for the development of spatial differences in annual ΔSOC. Hence, we were able to confirm that AC-based C budgets are able

  1. Detecting small-scale spatial differences and temporal dynamics of soil organic carbon (SOC) stocks: a comparison between automatic chamber-derived C budgets and repeated soil inventories

    Science.gov (United States)

    Hoffmann, Mathias; Jurisch, Nicole; Garcia Alba, Juana; Albiac Borraz, Elisa; Schmidt, Marten; Huth, Vytas; Rogasik, Helmut; Rieckh, Helene; Verch, Gernot; Sommer, Michael; Augustin, Jürgen

    2017-04-01

    Carbon (C) sequestration in soils plays a key role in the global C cycle. It is therefore crucial to adequately monitor dynamics in soil organic carbon (ΔSOC) stocks when aiming to reveal underlying processes and potential drivers. However, small-scale spatial and temporal changes in SOC stocks, particularly pronounced on arable lands, are hard to assess. The main reasons for this are limitations of the well-established methods. On the one hand, repeated soil inventories, often used in long-term field trials, reveal spatial patterns and trends in ΔSOC but require a longer observation period and a sufficient number of repetitions. On the other hand, eddy covariance measurements of C fluxes towards a complete C budget of the soil-plant-atmosphere system may help to obtain temporal ΔSOC patterns but lack small-scale spatial resolution. To overcome these limitations, this study presents a reliable method to detect both short-term temporal as well as small-scale spatial dynamics of ΔSOC. Therefore, a combination of automatic chamber (AC) measurements of CO2 exchange and empirically modeled aboveground biomass development (NPPshoot) was used. To verify our method, results were compared with ΔSOC observed by soil resampling. AC measurements were performed from 2010 to 2014 under a silage maize/winter fodder rye/sorghum-Sudan grass hybrid/alfalfa crop rotation at a colluvial depression located in the hummocky ground moraine landscape of NE Germany. Widespread in large areas of the formerly glaciated Northern Hemisphere, this depression type is characterized by a variable groundwater level (GWL) and pronounced small-scale spatial heterogeneity in soil properties, such as SOC and nitrogen (Nt). After monitoring the initial stage during 2010, soil erosion was experimentally simulated by incorporating topsoil material from an eroded midslope soil into the plough layer of the colluvial depression. SOC stocks were quantified before and after soil manipulation and at the end

  2. Weathering a Dynamic Seascape: Influences of Wind and Rain on a Seabird's Year-Round Activity Budgets.

    Directory of Open Access Journals (Sweden)

    Pierre A Pistorius

    Full Text Available How animals respond to varying environmental conditions is fundamental to ecology and is a question that has gained impetus due to mounting evidence indicating negative effects of global change on biodiversity. Behavioural plasticity is one mechanism that enables individuals and species to deal with environmental changes, yet for many taxa information on behavioural parameters and their capacity to change are lacking or restricted to certain periods within the annual cycle. This is particularly true for seabirds where year-round behavioural information is intrinsically challenging to acquire due to their reliance on the marine environment where they are difficult to study. Using data from over 13,000 foraging trips throughout the annual cycle, acquired using new-generation automated VHF technology, we described sex-specific, year-round activity budgets in Cape gannets. Using these data we investigated the role of weather (wind and rain on foraging activity and time allocated to nest attendance. Foraging activity was clearly influenced by wind speed, wind direction and rainfall during and outside the breeding season. Generally, strong wind conditions throughout the year resulted in relatively short foraging trips. Birds spent longer periods foraging when rainfall was moderate. Nest attendance, which was sex-specific outside of the breeding season, was also influenced by meteorological conditions. Large amounts of rainfall (> 2.5 mm per hour and strong winds (> 13 m s-1 resulted in gannets spending shorter amounts of time at their nests. We discuss these findings in terms of life history strategies and implications for the use of seabirds as bio-indicators.

  3. Effects of temperature on energy budget of Sparus macrocephalus%温度对黑鲷(Sparus macrocephalus)能量收支的影响

    Institute of Scientific and Technical Information of China (English)

    孙耀; 张波; 郭学武; 王俊; 唐启升

    2001-01-01

    The energy budget of Sparus macrocephalus was determined by continous-flow-through test method in the laboratory under deferent temperature condition.Results showed that,within the range of experiment temperature,all of food consumption energy(C),excretion energy(U),total metabolism energy(R)and growth energy(G)tended to deceleration increment with temperature's rise.The energy assigning models was expressed with 4 budget formulas.   The assigning models changed remarkably with temperature.In the models,assiging rates of metabolism and excretion energy changed as “U” shape with temperature's rise,but that of growth energy turned out contrary to it.Because metabolism and growth energy of Sparus macrocephalus takes 83.25%~91.70% and 8.30%~16.75% of assimilation energy respectively,it should belong to the fish of lower growth efficency and higher metabolism consumption.%在以玉筋鱼为饵料生物和最大摄食水平条件下,采用室内流水式实验,研究了黑鲷能量收支及温度对能量分配模式的影响。结果表明,黑鲷的摄食率、生长率、总代谢率和排泄率均随温度上升而呈减速增长趋势。不同温度条件下黑鲷的能量收支式为: 11.2±1.98℃ 100C=6.09F+9.38U+77.56R+7.02G 14.7±0.45℃ 100C=6.76F+8.75U+72.77R+11.82G 19.8±0.47℃ 100C=2.75F+8.94U+73.52R+14.79G 25.0±0.50℃ 100C=1.16F+9.18U+77.30R+12.81G 黑鲷的能量收支分配模式随温度而显著变化;其中能量代谢分配率和排泄分配率随温度升高呈U形变化趋势,而生长能分配率则恰恰相反。不同温度下黑鲷的代谢能占了同化能的83.25%~91.70%,生长能仅占8.30%~16.75%,可见黑鲷基本上属于低生长效率、高代谢消耗型鱼类。

  4. Charge and Energy Transfer Dynamics in Molecular Systems

    CERN Document Server

    May, Volkhard

    2004-01-01

    This second edition is based on the successful concept of the first edition in presenting a unified perspective on molecular charge and energy transfer processes. The authors bridge the regimes of coherent and dissipative dynamics, thus establishing the connection between classic rate theories and modern treatments of ultrafast phenomena. The book serves as an introduction for graduate students and researchers. Among the new topics of this second edition are. - semiclassical and quantum-classical hybrid formulations of molecular dynamics. - the basics of femtosecond nonlinear spectroscopy. - e

  5. Dynamics of dark energy models and centre manifolds

    CERN Document Server

    Boehmer, Christian G; Lazkoz, Ruth

    2011-01-01

    We analyse dark energy models where self-interacting three-forms or phantom fields drive the accelerated expansion of the Universe. The dynamics of such models is often studied by rewriting the cosmological field equations in the form of a system of autonomous differential equations, or simply a dynamical system. Properties of these systems are usually studied via linear stability theory. In situations where this method fails, for instance due to the presence of zero eigenvalues in the Jacobian, centre manifold theory can be applied. We present a concise introduction and show explicitly how to use this theory in two concrete examples.

  6. Dynamical dark energy in light of the latest observations

    Science.gov (United States)

    Zhao, Gong-Bo; Raveri, Marco; Pogosian, Levon; Wang, Yuting; Crittenden, Robert G.; Handley, Will J.; Percival, Will J.; Beutler, Florian; Brinkmann, Jonathan; Chuang, Chia-Hsun; Cuesta, Antonio J.; Eisenstein, Daniel J.; Kitaura, Francisco-Shu; Koyama, Kazuya; L'Huillier, Benjamin; Nichol, Robert C.; Pieri, Matthew M.; Rodriguez-Torres, Sergio; Ross, Ashley J.; Rossi, Graziano; Sánchez, Ariel G.; Shafieloo, Arman; Tinker, Jeremy L.; Tojeiro, Rita; Vazquez, Jose A.; Zhang, Hanyu

    2017-09-01

    A flat Friedmann-Robertson-Walker universe dominated by a cosmological constant (Λ) and cold dark matter (CDM) has been the working model preferred by cosmologists since the discovery of cosmic acceleration1,2. However, tensions of various degrees of significance are known to be present among existing datasets within the ΛCDM framework3-11. In particular, the Lyman-α forest measurement of the baryon acoustic oscillations (BAO) by the Baryon Oscillation Spectroscopic Survey3 prefers a smaller value of the matter density fraction ΩM than that preferred by cosmic microwave background (CMB). Also, the recently measured value of the Hubble constant, H0 = 73.24 ± 1.74 km s-1 Mpc-1 (ref. 12), is 3.4σ higher than the 66.93 ± 0.62 km s-1 Mpc-1 inferred from the Planck CMB data7. In this work, we investigate whether these tensions can be interpreted as evidence for a non-constant dynamical dark energy. Using the Kullback-Leibler divergence13 to quantify the tension between datasets, we find that the tensions are relieved by an evolving dark energy, with the dynamical dark energy model preferred at a 3.5σ significance level based on the improvement in the fit alone. While, at present, the Bayesian evidence for the dynamical dark energy is insufficient to favour it over ΛCDM, we show that, if the current best-fit dark energy happened to be the true model, it would be decisively detected by the upcoming Dark Energy Spectroscopic Instrument survey14.

  7. Energy budgets of animals: behavioral and ecological implications. Progress report. [Egg laying in laboratory by desert lizards

    Energy Technology Data Exchange (ETDEWEB)

    Porter, W.P.

    1975-05-01

    Climate effects on biomass requirements for mammal and reptile maintenance, growth, and reproduction and implications for climate-influenced population dynamics were explored using computer simulations. The simulations revealing critical shortages of appropriate data have led to the design of experiments to acquire the needed information. The development of a technique to induce repeated egg laying in the laboratory for reproduction studies of some desert lizards was accomplished this year. (CH)

  8. Dynamics of anion-molecule reactions at low energy

    Energy Technology Data Exchange (ETDEWEB)

    Mikosch, J.

    2007-11-15

    Anion-molecule reactions must find their way through deeply bound entrance and exit channel complexes separated by a central barrier. This results in low reaction rates and rich dynamics since direct pathways compete with the formation of transient intermediates. In this thesis we examine the probability of proton transfer to a small anion and transient lifetimes of a thermoneutral bimolecular nucleophilic substitution (S{sub N}2) reaction at well defined variable temperature down to 8 Kelvin in a multipole trap. The observed strong inverse temperature dependence is attributed to the deficit of available quantum states in the entrance channel at decreasing temperature. Furthermore we investigate scattering dynamics of S{sub N}2 reactions at defined relative energy between 0.4 and 10 eV by crossed beam slice imaging. A weakly exothermic reaction with high central barrier proceeds via an indirect, complex-mediated mechanism at low relative energies featuring high internal product excitation in excellent quantitative agreement with a statistical model. In contrast, direct backward scattering prevails for higher energies with product velocities close to the kinematical cutoff. For a strongly exothermic reaction, competing S{sub N}2-, dihalide- and proton transfer-channels are explored which proceed by complex mediation for low energy and various rebound-, grazing- and collision induced bond rupture-mechanisms at higher energy. From our data and a collaboration with theory we identify a new indirect roundabout S{sub N}2 mechanism involving CH{sub 3}-rotation. (orig.)

  9. Nuclear Hybrid Energy System Modeling: RELAP5 Dynamic Coupling Capabilities

    Energy Technology Data Exchange (ETDEWEB)

    Piyush Sabharwall; Nolan Anderson; Haihua Zhao; Shannon Bragg-Sitton; George Mesina

    2012-09-01

    The nuclear hybrid energy systems (NHES) research team is currently developing a dynamic simulation of an integrated hybrid energy system. A detailed simulation of proposed NHES architectures will allow initial computational demonstration of a tightly coupled NHES to identify key reactor subsystem requirements, identify candidate reactor technologies for a hybrid system, and identify key challenges to operation of the coupled system. This work will provide a baseline for later coupling of design-specific reactor models through industry collaboration. The modeling capability addressed in this report focuses on the reactor subsystem simulation.

  10. Energy deposition dynamics of femtosecond pulses in water

    Energy Technology Data Exchange (ETDEWEB)

    Minardi, Stefano, E-mail: stefano@stefanominardi.eu; Pertsch, Thomas [Institute of Applied Physics, Friedrich-Schiller-Universität Jena, Max-Wien-Platz 1, 07743 Jena (Germany); Milián, Carles; Couairon, Arnaud [Centre de Physique Théorique, CNRS, École Polytechnique, F-91128 Palaiseau (France); Majus, Donatas; Tamošauskas, Gintaras; Dubietis, Audrius [Department of Quantum Electronics, Vilnius University, Sauletekio 9, bldg. 3, LT-10222 Vilnius (Lithuania); Gopal, Amrutha [Institute of Optics and Quantum Electronics, Friedrich-Schiller-Universität Jena, Max-Wien-Platz 1, 07743 Jena (Germany)

    2014-12-01

    We exploit inverse Raman scattering and solvated electron absorption to perform a quantitative characterization of the energy loss and ionization dynamics in water with tightly focused near-infrared femtosecond pulses. A comparison between experimental data and numerical simulations suggests that the ionization energy of water is 8 eV, rather than the commonly used value of 6.5 eV. We also introduce an equation for the Raman gain valid for ultra-short pulses that validates our experimental procedure.

  11. Global Carbon Budget 2015

    Science.gov (United States)

    Le Quéré, C.; Moriarty, R.; Andrew, R. M.; Canadell, J. G.; Sitch, S.; Korsbakken, J. I.; Friedlingstein, P.; Peters, G. P.; Andres, R. J.; Boden, T. A.; Houghton, R. A.; House, J. I.; Keeling, R. F.; Tans, P.; Arneth, A.; Bakker, D. C. E.; Barbero, L.; Bopp, L.; Chang, J.; Chevallier, F.; Chini, L. P.; Ciais, P.; Fader, M.; Feely, R. A.; Gkritzalis, T.; Harris, I.; Hauck, J.; Ilyina, T.; Jain, A. K.; Kato, E.; Kitidis, V.; Klein Goldewijk, K.; Koven, C.; Landschützer, P.; Lauvset, S. K.; Lefèvre, N.; Lenton, A.; Lima, I. D.; Metzl, N.; Millero, F.; Munro, D. R.; Murata, A.; Nabel, J. E. M. S.; Nakaoka, S.; Nojiri, Y.; O'Brien, K.; Olsen, A.; Ono, T.; Pérez, F. F.; Pfeil, B.; Pierrot, D.; Poulter, B.; Rehder, G.; Rödenbeck, C.; Saito, S.; Schuster, U.; Schwinger, J.; Séférian, R.; Steinhoff, T.; Stocker, B. D.; Sutton, A. J.; Takahashi, T.; Tilbrook, B.; van der Laan-Luijkx, I. T.; van der Werf, G. R.; van Heuven, S.; Vandemark, D.; Viovy, N.; Wiltshire, A.; Zaehle, S.; Zeng, N.

    2015-12-01

    Accurate assessment of anthropogenic carbon dioxide (CO2) emissions and their redistribution among the atmosphere, ocean, and terrestrial biosphere is important to better understand the global carbon cycle, support the development of climate policies, and project future climate change. Here we describe data sets and a methodology to quantify all major components of the global carbon budget, including their uncertainties, based on the combination of a range of data, algorithms, statistics, and model estimates and their interpretation by a broad scientific community. We discuss changes compared to previous estimates as well as consistency within and among components, alongside methodology and data limitations. CO2 emissions from fossil fuels and industry (EFF) are based on energy statistics and cement production data, while emissions from land-use change (ELUC), mainly deforestation, are based on combined evidence from land-cover-change data, fire activity associated with deforestation, and models. The global atmospheric CO2 concentration is measured directly and its rate of growth (GATM) is computed from the annual changes in concentration. The mean ocean CO2 sink (SOCEAN) is based on observations from the 1990s, while the annual anomalies and trends are estimated with ocean models. The variability in SOCEAN is evaluated with data products based on surveys of ocean CO2 measurements. The global residual terrestrial CO2 sink (SLAND) is estimated by the difference of the other terms of the global carbon budget and compared to results of independent dynamic global vegetation models forced by observed climate, CO2, and land-cover change (some including nitrogen-carbon interactions). We compare the mean land and ocean fluxes and their variability to estimates from three atmospheric inverse methods for three broad latitude bands. All uncertainties are reported as ±1σ, reflecting the current capacity to characterise the annual estimates of each component of the global

  12. Effective Field Theory of Dark Energy: a Dynamical Analysis

    CERN Document Server

    Frusciante, Noemi; Silvestri, Alessandra

    2013-01-01

    The effective field theory (EFT) of dark energy relies on three functions of time to describe the background dynamics. The viability of these functions is investigated here by means of a thorough dynamical analysis. While the system is underdetermined, and one can always find a set of functions reproducing any expansion history, we are able to determine general compatibility conditions for these functions by requiring a viable background cosmology. In particular, we identify a set of variables that allows us to transform the non-autonomous system of equations into an infinite-dimensional one characterized by a significant recursive structure. We then analyze several autonomous sub-systems, obtained truncating the original one at increasingly higher dimension, that correspond to increasingly general models of dark energy and modified gravity. Furthermore, we exploit the recursive nature of the system to draw some general conclusions on the different cosmologies that can be recovered within the EFT formalism an...

  13. The Radiated Energy Budget of Chromospheric Plasma in a Major Solar Flare Deduced From Multi-Wavelength Observations

    CERN Document Server

    Milligan, Ryan O; Dennis, Brian R; Hudson, Hugh S; Fletcher, Lyndsay; Allred, Joel C; Chamberlin, Phillip C; Ireland, Jack; Mathioudakis, Mihalis; Keenan, Francis P

    2014-01-01

    This paper presents measurements of the energy radiated by the lower solar atmosphere, at optical, UV, and EUV wavelengths, during an X-class solar flare (SOL2011-02-15T01:56) in response to an injection of energy assumed to be in the form of nonthermal electrons. Hard X-ray observations from RHESSI were used to track the evolution of the parameters of the nonthermal electron distribution to reveal the total power contained in flare accelerated electrons. By integrating over the duration of the impulsive phase, the total energy contained in the nonthermal electrons was found to be $>2\\times10^{31}$ erg. The response of the lower solar atmosphere was measured in the free-bound EUV continua of H I (Lyman), He I, and He II, plus the emission lines of He II at 304\\AA\\ and H I (Ly$\\alpha$) at 1216\\AA\\ by SDO/EVE, the UV continua at 1600\\AA\\ and 1700\\AA\\ by SDO/AIA, and the WL continuum at 4504\\AA, 5550\\AA, and 6684\\AA, along with the Ca II H line at 3968\\AA\\ using Hinode/SOT. The summed energy detected by these in...

  14. Coarse Molecular Dynamics of a Peptide Fragment Free Energy, Kinetics, and Long-Time Dynamics Computations

    CERN Document Server

    Hummer, G; Hummer, Gerhard; Kevrekidis, Ioannis G.

    2002-01-01

    We present a ``coarse molecular dynamics'' approach and apply it to studying the kinetics and thermodynamics of a peptide fragment dissolved in water. Short bursts of appropriately initialized simulations are used to infer the deterministic and stochastic components of the peptide motion parametrized by an appropriate set of coarse variables. Techniques from traditional numerical analysis (Newton-Raphson, coarse projective integration) are thus enabled; these techniques help analyze important features of the free-energy landscape (coarse transition states, eigenvalues and eigenvectors, transition rates, etc.). Reverse integration of (irreversible) expected coarse variables backward in time can assist escape from free energy minima and trace low-dimensional free energy surfaces. To illustrate the ``coarse molecular dynamics'' approach, we combine multiple short (0.5-ps) replica simulations to map the free energy surface of the ``alanine dipeptide'' in water, and to determine the ~ 1/(1000 ps) rate of interconv...

  15. Energy budgets, growth rates, and thermal constraints: toward an integrative approach to the study of life-history variation.

    Science.gov (United States)

    Niewiarowski, P H

    2001-04-01

    Variation in thermal constraints on activity has been hypothesized to be an important ecological source of geographic variation in growth rates of juvenile eastern fence lizards Sceloporus undulatus. However, most of the evidence to support this hypothesis is either inferential or indirect. In this study, I quantitatively compared thermal constraints on activity and their relationship to growth rates of free-ranging juvenile fence lizards from two extremes of the range of variation in growth rate (Nebraska and New Jersey) used in a reciprocal transplant experiment. I also examined energy allocation made to growth and storage by yearling lizards. Reduced growth rates in New Jersey of normally fast-growing hatchlings from Nebraska were associated with a more stringent thermal constraint on activity corresponding to a 2-3-h shorter predicted daily activity period in New Jersey compared to Nebraska. The thermal constraint on activity was particularly strong (24% less time available in New Jersey compared to Nebraska) during the period when hatchling lizards emerge (August-October). An 8% reduction in total activity time available over the course of a single year was associated with a 7% reduction in the total amount of energy accumulated by lizards in New Jersey. Differences in the total amount of energy available for allocation were also accompanied by differences in how energy was allocated. Lizards from New Jersey had an allocatable energy pool of approximately 40.34 kJ (88% to growth, 12% to storage, and 0% to reproduction). Lizards from Nebraska had an allocatable pool of 43.44 kJ (22% to growth, 18% to storage, and 60% to reproduction). This study joins others in advocating and illustrating an integrative approach to determining the causes and consequences of life-history variation by combining experimental, comparative, and phylogenetic methods in a single system.

  16. Modeling the dynamic modulation of light energy in photosynthetic algae.

    Science.gov (United States)

    Papadakis, Ioannis A; Kotzabasis, Kiriakos; Lika, Konstadia

    2012-05-01

    An integrated cell-based dynamic mathematical model that take into account the role of the photon absorbing process, the partition of excitation energy, and the photoinactivation and repair of photosynthetic units, under variable light and dissolved inorganic carbon (DIC) availability is proposed. The modeling of the photon energy absorption and the energy dissipation is based on the photoadaptive changes of the underlying mechanisms. The partition of the excitation energy is based on the relative availability of light and DIC to the cell. The modeling of the photoinactivation process is based on the common aspect that it occurs under any light intensity and the modeling of the repair process is based on the evidence that it is controlled by chloroplast and nuclear-encoded enzymes. The present model links the absorption of photons and the partitioning of excitation energy to the linear electron flow and other quenchers with chlorophyll fluorescence emission parameters, and the number of the functional photosynthetic units with the photosynthetic oxygen production rate. The energy allocation to the LEF increases as DIC availability increases and/or light intensity decreases. The rate of rejected energy increases with light intensity and with DIC availability. The resulting rate coefficient of photoinactivation increases as light intensity and/or as DIC concentration increases. We test the model against chlorophyll fluorescence induction and photosynthetic oxygen production rate measurements, obtained from cultures of the unicellular green alga Scenedesmus obliquus, and find a very close quantitative and qualitative correspondence between predictions and data.

  17. A Dynamic Dark Information Energy Consistent with Planck Data

    Directory of Open Access Journals (Sweden)

    Michael Paul Gough

    2014-03-01

    Full Text Available The 2013 cosmology results from the European Space Agency Planck spacecraft provide new limits to the dark energy equation of state parameter. Here we show that Holographic Dark Information Energy (HDIE, a dynamic dark energy model, achieves an optimal fit to the published datasets where Planck data is combined with other astrophysical measurements. HDIE uses Landauer’s principle to account for dark energy by the energy equivalent of information, or entropy, of stellar heated gas and dust. Combining Landauer’s principle with the Holographic principle yields an equation of state parameter determined solely by star formation history, effectively solving the “cosmic coincidence problem”. While HDIE mimics a cosmological constant at low red-shifts, z < 1, the small difference from a cosmological constant expected at higher red-shifts will only be resolved by the next generation of dark energy instrumentation. The HDIE model is shown to provide a viable alternative to the main cosmological constant/vacuum energy and scalar field/ quintessence explanations.

  18. The impacts of a plume-rise scheme on earth system modeling: climatological effects of biomass aerosols on the surface temperature and energy budget of South America

    Science.gov (United States)

    de Menezes Neto, Otacilio L.; Coutinho, Mariane M.; Marengo, José A.; Capistrano, Vinícius B.

    2017-08-01

    Seasonal forest fires in the Amazon are the largest source of pollutants in South America. The impacts of aerosols due to biomass burning on the temperature and energy balance in South America are investigated using climate simulations from 1979 to 2005 using HadGEM2-ES, which includes the hot plume-rise scheme (HPR) developed by Freitas et al. (Estudos Avançados 19:167-185, 2005, Atmos Chem Phys 7:3385-3398, 2007, Atmos Chem Phys 10:585-594, 2010). The HPR scheme is used to estimate the vertical heights of biomass-burning aerosols based on the thermodynamic characteristics of the underlying model. Three experiments are performed. The first experiment includes the HPR scheme, the second experiment turns off the HPR scheme and the effects of biomass aerosols (BIOMASS OFF), and the final experiment assumes that all biomass aerosols are released at the surface (HPR OFF). Relative to the BIOMASS OFF experiment, the temperature decreased in the HPR experiment as the net shortwave radiation at the surface decreased in a region with a large amount of biomass aerosols. When comparing the HPR and HPR OFF experiments, the release of biomass aerosols higher on the atmosphere impacts on temperature and the energy budget because the aerosols were transported by strong winds in the upper atmospheric levels.

  19. Vibrational energy transfer dynamics in ruthenium polypyridine transition metal complexes.

    Science.gov (United States)

    Fedoseeva, Marina; Delor, Milan; Parker, Simon C; Sazanovich, Igor V; Towrie, Michael; Parker, Anthony W; Weinstein, Julia A

    2015-01-21

    Understanding the dynamics of the initial stages of vibrational energy transfer in transition metal complexes is a challenging fundamental question which is also of crucial importance for many applications, such as improving the performance of solar devices or photocatalysis. The present study investigates vibrational energy transport in the ground and the electronic excited state of Ru(4,4'-(COOEt)2-2,2-bpy)2(NCS)2, a close relative of the efficient "N3" dye used in dye-sensitized solar cells. Using the emerging technique of ultrafast two-dimensional infrared spectroscopy, we show that, similarly to other transition-metal complexes, the central Ru heavy atom acts as a "bottleneck" making the energy transfer from small ligands with high energy vibrational stretching frequencies less favorable and thereby affecting the efficiency of vibrational energy flow in the complex. Comparison of the vibrational relaxation times in the electronic ground and excited state of Ru(4,4'-(COOEt)2-2,2-bpy)2(NCS)2 shows that it is dramatically faster in the latter. We propose to explain this observation by the intramolecular electrostatic interactions between the thiocyanate group and partially oxidised Ru metal center, which increase the degree of vibrational coupling between CN and Ru-N modes in the excited state thus reducing structural and thermodynamic barriers that slow down vibrational relaxation and energy transport in the electronic ground state. As a very similar behavior was earlier observed in another transition-metal complex, Re(4,4'-(COOEt)2-2,2'-bpy)(CO)3Cl, we suggest that this effect in vibrational energy dynamics might be common for transition-metal complexes with heavy central atoms.

  20. Approaches to the Organization of the Energy Efficient Activity at the Regional Level in the Context of Limited Budget Resources during the Transformation of Energy Market Paradigm

    Science.gov (United States)

    Vakulenko, Ihor; Myroshnychenko, Iuliia

    2015-12-01

    The research is devoted to the problem of the assessment of the integrated projects investment efficiency, energy saving and energy efficiency measures for social and municipal buildings within the course aimed at the reduction of the natural gas consumption and its replacement by alternative fuel types, that is important for a number of European countries, and Ukraine in particular. The objectives of the research are as follows: comparative assessment of the quality of integrated and element-by-element approaches to energy saving encompassing investment, environmental, social and organizational aspects; the formulation of practical recommendations to improve the efficiency of development and implementation of integrated programs in the field of energy saving and energy efficiency. It is proposed to use the methodology of system analysis with the elements of deduction that is practical and that allows to set key factors that influence the processes of energy replacement and energy efficiency increase, as well as factors that constrain them.

  1. Exploiting Dynamic Workload Variation in Low Energy Preemptive Task Scheduling

    CERN Document Server

    Leung, Lap-Fai; Hu, Xiaobo Sharon

    2011-01-01

    A novel energy reduction strategy to maximally exploit the dynamic workload variation is proposed for the offline voltage scheduling of preemptive systems. The idea is to construct a fully-preemptive schedule that leads to minimum energy consumption when the tasks take on approximately the average execution cycles yet still guarantees no deadline violation during the worst-case scenario. End-time for each sub-instance of the tasks obtained from the schedule is used for the on-line dynamic voltage scaling (DVS) of the tasks. For the tasks that normally require a small number of cycles but occasionally a large number of cycles to complete, such a schedule provides more opportunities for slack utilization and hence results in larger energy saving. The concept is realized by formulating the problem as a Non-Linear Programming (NLP) optimization problem. Experimental results show that, by using the proposed scheme, the total energy consumption at runtime is reduced by as high as 60% for randomly generated task set...

  2. Measurements of radiated elastic wave energy from dynamic tensile cracks

    Science.gov (United States)

    Boler, Frances M.

    1990-01-01

    The role of fracture-velocity, microstructure, and fracture-energy barriers in elastic wave radiation during a dynamic fracture was investigated in experiments in which dynamic tensile cracks of two fracture cofigurations of double cantilever beam geometry were propagating in glass samples. The first, referred to as primary fracture, consisted of fractures of intact glass specimens; the second configuration, referred to as secondary fracture, consisted of a refracture of primary fracture specimens which were rebonded with an intermittent pattern of adhesive to produce variations in fracture surface energy along the crack path. For primary fracture cases, measurable elastic waves were generated in 31 percent of the 16 fracture events observed; the condition for radiation of measurable waves appears to be a local abrupt change in the fracture path direction, such as occurs when the fracture intersects a surface flaw. For secondary fractures, 100 percent of events showed measurable elastic waves; in these fractures, the ratio of radiated elastic wave energy in the measured component to fracture surface energy was 10 times greater than for primary fracture.

  3. Grid Integration and Dynamic Impact of Wind Energy

    CERN Document Server

    Vittal, Vijay

    2013-01-01

    Grid Integration and Dynamic Impact of Wind Energy details the integration of wind energy resources to the electric grid worldwide. Authors Vijay Vittal and Raja Ayyanar include detailed coverage of the power converters and control used in interfacing electric machines and power converters used in wind generators, and extensive descriptions of power systems operation and control to accommodate large penetration of wind resources. Key concepts will be illustrated through extensive power electronics and power systems simulations using software like MATLAB, Simulink and PLECS. The book addresses real world problems and solutions in the area of grid integration of wind resources, and will be a valuable resource for engineers and researchers working in renewable energy and power.

  4. Glassy protein dynamics and gigantic solvent reorganization energy of plastocyanin

    CERN Document Server

    LeBard, David N

    2007-01-01

    We report the results of Molecular Dynamics simulations of electron transfer activation parameters of plastocyanin metalloprotein involved as electron carrier in natural photosynthesis. We have discovered that slow, non-ergodic conformational fluctuations of the protein, coupled to hydrating water, result in a very broad distribution of donor-acceptor energy gaps far exceeding that observed for commonly studied inorganic and organic donor-acceptor complexes. The Stokes shift is not affected by these fluctuations and can be calculated from solvation models in terms of the response of the solvent dipolar polarization. The non-ergodic character of large-amplitude protein/water mobility breaks the strong link between the Stokes shift and reorganization energy characteristic of equilibrium (ergodic) theories of electron transfer. This mechanism might be responsible for low activation barriers in natural electron transfer proteins characterized by low reaction free energy.

  5. Interacting Ghost Dark Energy Model: Dynamical System Analysis

    CERN Document Server

    Golchin, Hanif; Ebrahimi, Esmaeil

    2016-01-01

    We study the impacts of interaction between dark matter and dark energy in the context of ghost dark energy model. Using the dynamical system analysis, we obtain the fixed points of the system for different types of interactions while the universe is filled with radiation, matter (including dark matter and luminous matter) and dark energy components. We consider the stability of the fixed points in details for different cases. In all cases there is an unstable matter dominated epoch and a stable late time dark energy dominated phase. However, we find that adding the linear interaction, the evolution of ghost dark energy model does not contain the radiation dominated epoch in the early times which is a necessary point in any cosmic model. This failure resolved when we add the non-linear interaction to the model. We also find an upper bound for the value of the coupling constant of the interaction between dark matter and dark energy as b < 0.57 . This bound is necessary to have a decelerating and unstable ma...

  6. A Defense Budget Primer

    Science.gov (United States)

    1998-12-09

    budget practices. See Appendix D for the actual timetable of congressional action on the FY1999 budget.65 See James V. Saturno , The Appropriations...details, see James V. Saturno , The Appropriations Process and the Congressional69 Budget Act, CRS Report 97-947. Table 6. Milestone Votes on the Defense...James V. Saturno , The74 Appropriations Process and the Congressional Budget Act, CRS Report 97-947. The Budget Enforcement Act of 1990 and subsequent

  7. The Effect of de-Sitter Like Background on Increasing the Zero Point Budget of Dark Energy

    Directory of Open Access Journals (Sweden)

    Haidar Sheikhahmadi

    2016-01-01

    Full Text Available During this work, using subtraction renormalization mechanism, zero point quantum fluctuations for bosonic scalar fields in a de-Sitter like background are investigated. By virtue of the observed value for spectral index, ns(k, for massive scalar field the best value for the first slow roll parameter, ϵ, is achieved. In addition, the energy density of vacuum quantum fluctuations for massless scalar field is obtained. The effects of these fluctuations on other components of the universe are studied. By solving the conservation equation, for some different examples, the energy density for different components of the universe is obtained. In the case which all components of the universe are in an interaction, the different dissipation functions, Q~i, are considered. The time evolution of ρDE(z/ρcri(z shows that Q~=3γH(tρm has the best agreement in comparison to observational data including CMB, BAO, and SNeIa data set.

  8. GEM/POPs: a global 3-D dynamic model for semi-volatile persistent organic pollutants – Part 2: Global transports and budgets of PCBs

    Directory of Open Access Journals (Sweden)

    L. A. Barrie

    2007-03-01

    Full Text Available Global transports and budgets of three PCBs were investigated with a 3-D dynamic model for semi-volatile persistent organic pollutants – GEM/POPs. Dominant pathways were identified for PCB transports in the atmosphere with a peak transport flux below 8 km and 14 km for gaseous and particulate PCB28, 4 km and 6 km for gaseous and particulate PCB180. The inter-continental transports of PCBs in the Northern Hemisphere (NH are dominated in the zonal direction with their route changes seasonally regulated by the variation of westerly jet. The transport pathways from Europe and North Atlantic to the Arctic contributed the most PCBs over there. Inter-hemispheric transports of PCBs originated from the regions of Europe, Asia and North America in three different flow-paths, accompanying with easterly jet, Asian monsoon winds and trade winds. PCBs from the Southern Hemisphere (SH could export into the NH. According to the PCB emissions of year 2000, Europe, North America and Asia are the three largest sources of the three PCBs, contributing to the global background concentrations in the atmosphere and soil and water. Globally, PCB28 in soil and water has become a comparable source to the anthropogenic emissions while heavier PCBs such as PCB153 and 180 are still transporting into soil and water. It is found that lighter PCBs have more long range transport potentials than their heavier counter-parts in the atmosphere.

  9. Development of response models for the Earth Radiation Budget Experiment (ERBE) sensors. Part 1: Dynamic models and computer simulations for the ERBE nonscanner, scanner and solar monitor sensors

    Science.gov (United States)

    Halyo, Nesim; Choi, Sang H.; Chrisman, Dan A., Jr.; Samms, Richard W.

    1987-01-01

    Dynamic models and computer simulations were developed for the radiometric sensors utilized in the Earth Radiation Budget Experiment (ERBE). The models were developed to understand performance, improve measurement accuracy by updating model parameters and provide the constants needed for the count conversion algorithms. Model simulations were compared with the sensor's actual responses demonstrated in the ground and inflight calibrations. The models consider thermal and radiative exchange effects, surface specularity, spectral dependence of a filter, radiative interactions among an enclosure's nodes, partial specular and diffuse enclosure surface characteristics and steady-state and transient sensor responses. Relatively few sensor nodes were chosen for the models since there is an accuracy tradeoff between increasing the number of nodes and approximating parameters such as the sensor's size, material properties, geometry, and enclosure surface characteristics. Given that the temperature gradients within a node and between nodes are small enough, approximating with only a few nodes does not jeopardize the accuracy required to perform the parameter estimates and error analyses.

  10. IMPLEMENTATION APPROACHES DURING SIMULATION OF ENERGY PROCESSES FOR A DYNAMICALLY POSITIONED SHIP

    Directory of Open Access Journals (Sweden)

    V.V. Budashko

    2015-12-01

    Full Text Available Purpose. Creation of a mathematical model of the ship's power plant (SPP combined propulsion complexes (CPC that takes into account the behavior of all objects, including the ship itself, the transfer of power from the medium speed diesel generators on the propellers, which will allow to take into account the hydrodynamic properties of the vessel and their impact on the energy processes in SPP CPC. Methodology. The analysis of energy processes in the SPP CPC in different operating conditions resulted in creation of a strategy for constructing mathematical models of SPP CPC. This strategy is based on the implementation on the vector plane resulting power characteristics of SPP vectors disturbances, leading to the deviation of the hydrodynamic characteristics of the ship during operation dynamic positioning. The result allowed to consider not only the features of setting PID-governors of frequency converters of electric thrusters but the automatic voltage regulators of medium speed diesel generators as well. Results. Within the research work a software package Ships_CPC in MatLab/Simulink was developed under the state budget project «Concepts, technologies and ways of improving ship power plants combined propulsion complexes» at the Department of Electromechanics and Electrical Engineering of Odessa National Maritime Academy. Originality. This complex represents a set of functional blocks of the components SPP CPC, built on the principle of «input-output». The simulation results demonstrate the ability to use software package Ships_CPC to study the effect of various settings on the energy regulators of processes SPP CPC, which can develop and integrate the different strategies of automatic voltage regulators. Practical value. Since software complex Ships_CPC was developed under Open system technology, it can reorganize, re-tune and integrate in processes of any difficulties with further completion in the form of a universal structure.

  11. FY 1996 Congressional budget request: Budget highlights

    Energy Technology Data Exchange (ETDEWEB)

    1995-02-01

    The FY 1996 budget presentation is organized by the Department`s major business lines. An accompanying chart displays the request for new budget authority. The report compares the budget request for FY 1996 with the appropriated FY 1995 funding levels displayed on a comparable basis. The FY 1996 budget represents the first year of a five year plan in which the Department will reduce its spending by $15.8 billion in budget authority and by $14.1 billion in outlays. FY 1996 is a transition year as the Department embarks on its multiyear effort to do more with less. The Budget Highlights are presented by business line; however, the fifth business line, Economic Productivity, which is described in the Policy Overview section, cuts across multiple organizational missions, funding levels and activities and is therefore included in the discussion of the other four business lines.

  12. Examining fine potential energy effects in high-energy fission dynamics

    Science.gov (United States)

    Mazurek, K.; Schmitt, C.; Nadtochy, P. N.; Kmiecik, M.; Maj, A.; Wasiak, P.; Wieleczko, J. P.

    2013-11-01

    The potential energy surface plays a decisive role in nuclear fission. Together with inertia and viscosity, it influences the trajectory of the system, and the properties of the fission fragments result from the puzzling interplay between static and dynamical effects. A careful study on the influence of the parametrization of the potential energy landscape in heavy-ion-induced fission is performed. Dynamical calculations are done within the stochastic Langevin approach in a three-dimensional deformation space. Various prescriptions of the potential energy surface are considered, probing two different Liquid Drop models and the deformation dependence of the Wigner/congruence energy. A wide set of observables, including cross sections, particle multiplicities, and integral, as well as isotopic and isobaric, distributions of fission and evaporation products, is analyzed. Nuclei close to the Businaro-Gallone point are confirmed to be well suited for investigating the Liquid Drop parametrization, while the influence of the deformation-dependent Wigner/congruence energy is difficult to demonstrate unambiguously in fission at high excitation energies.

  13. Historical analysis and modeling of the forest carbon dynamics using the Carbon Budget Model: an example for the Trento Province (NE, Italy

    Directory of Open Access Journals (Sweden)

    Pilli R

    2014-02-01

    Full Text Available Historical analysis and modeling of the forest carbon dynamics using the Carbon Budget Model: an example for the Trento Province (NE, Italy. The Carbon Budget Model (CBM-CFS3 developed by the Canadian Forest Service was applied to data collected by the last Italian National Forest Inventory (INFC for the Trento Province (NE, Italy. CBM was modified and adapted to the different management types (i.e., even-aged high forests, uneven-aged high forests and coppices and silvicultural systems (including clear cuts, single tree selection systems and thinning applied in this province. The aim of this study was to provide an example of down-scaling of this model from a national to a regional scale, providing (i an historical analysis, from 1995 to 2011, and (ii a projection, from 2012 to 2020, of the forest biomass and the carbon stock evolution. The analysis was based on the harvest rate reported by the Italian National Institute of Statistics (from 1995 to 2011, corrected according to the last INFC data and distinguished between timber and fuel woods and between conifers and broadleaves. Since 2012, we applied a constant harvest rate, equal to about 1300 Mm3 yr-1, estimated from the average harvest rate for the period 2006-2011. Model results were consistent with similar data reported in the literature. The average biomass C stock was 90 Mg C ha-1 and the biomass C stock change was 0.97 Mg C ha-1 yr-1 and 0.87 Mg C ha-1 yr-1, for the period 1995 -2011 and 2012-2020, respectively. The C stock cumulated by the timber products since 1995 was 96 Gg C yr-1, i.e., about 28% of the average annual C stock change of the forests, equal to 345 Gg C yr-1. CBM also provided estimates on the evolution of the age class distribution of the even-aged forests and on the C stock of the DOM forest pools (litter, dead wood and soil. This study demonstrates the utility of CBM to provide estimates at a regional or local scale, using not only the data provided by the forest

  14. Toward an Improved Understanding of the Tropical Energy Budget Using TRMM-based Atmospheric Radiative Heating Products

    Science.gov (United States)

    L'Ecuyer, T.; McGarragh, G.; Ellis, T.; Stephens, G.; Olson, W.; Grecu, M.; Shie, C.; Jiang, X.; Waliser, D.; Li, J.; Tian, B.

    2008-05-01

    It is widely recognized that clouds and precipitation exert a profound influence on the propagation of radiation through the Earth's atmosphere. In fact, feedbacks between clouds, radiation, and precipitation represent one of the most important unresolved factors inhibiting our ability to predict the consequences of global climate change. Since its launch in late 1997, the Tropical Rainfall Measuring Mission (TRMM) has collected more than a decade of rainfall measurements that now form the gold standard of satellite-based precipitation estimates. Although not as widely advertised, the instruments aboard TRMM are also well-suited to the problem of characterizing the distribution of atmospheric heating in the tropics and a series of algorithms have recently been developed for estimating profiles of radiative and latent heating from these measurements. This presentation will describe a new multi-sensor tropical radiative heating product derived primarily from TRMM observations. Extensive evaluation of the products using a combination of ground and satellite-based observations is used to place the dataset in the context of existing techniques for quantifying atmospheric radiative heating. Highlights of several recent applications of the dataset will be presented that illustrate its utility for observation-based analysis of energy and water cycle variability on seasonal to inter-annual timescales and evaluating the representation of these processes in numerical models. Emphasis will be placed on the problem of understanding the impacts of clouds and precipitation on atmospheric heating on large spatial scales, one of the primary benefits of satellite observations like those provided by TRMM.

  15. Muscle fibre size optimisation provides flexibility for energy budgeting in calorie-restricted coho salmon transgenic for growth hormone.

    Science.gov (United States)

    Johnston, Ian A; de la Serrana, Daniel Garcia; Devlin, Robert H

    2014-10-01

    Coho salmon (Oncorhynchus kisutch) transgenic for growth hormone (GH) show substantially faster growth than wild-type (WT) fish. We fed GH-transgenic salmon either to satiation (1 year; TF) or the same smaller ration of wild-type fish (2 years; TR), resulting in groups matched for body size to WT salmon. The myotomes of TF and WT fish had the same number and size distribution of muscle fibres, indicating a twofold higher rate of fibre recruitment in the GH transgenics. Unexpectedly, calorie restriction was found to decrease the rate of fibre production in transgenics, resulting in a 20% increase in average fibre size and reduced costs of ionic homeostasis. Genes for myotube formation were downregulated in TR relative to TF and WT fish. We suggest that muscle fibre size optimisation allows the reallocation of energy from maintenance to locomotion, explaining the observation that calorie-restricted transgenics grow at the same rate as WT fish whilst exhibiting markedly higher foraging activity.

  16. Budget impact analysis of a pneumococcal vaccination programme in the 65-year-old Spanish cohort using a dynamic model

    Science.gov (United States)

    2013-01-01

    Background This study aimed to assess the costs and clinical benefits of the 13-valent pneumococcal conjugate vaccine (PCV13) administered annually to the 65-year-old cohort in Spain versus the alternative of not vaccinating patients and treating them only when infected. Methods Cases of pneumococcal disease avoided were calculated through a dynamic model based on the work of Anderson and May (1999). Sixty-six percent of the 65-year-old cohort was assumed to have been vaccinated with one PCV13 dose (304,492 subjects). Base-case estimated vaccine effectiveness and serotype coverage were 58% and 60%, respectively. Disease-related costs were calculated based on published data. Results Over the 5-year period, a total of 125,906 cases of pneumococcal disease would be avoided. Net savings of €102 million would be obtained. The cost-saving distribution was not homogeneous, starting in the 2nd year and increasing through the 5th. To demonstrate model robustness, an additional scenario analysis was performed using extreme values of model parameters (vaccination programme coverage, vaccine effectiveness, discount rate and disease costs). Under those scenarios, net savings were always achieved. Conclusions Based on the assumptions of the model, the 65-year-cohort pneumococcal vaccination campaign appears to be a cost-saving intervention in the Spanish population under different scenarios. PMID:23578307

  17. Potential energy surfaces and reaction dynamics of polyatomic molecules

    Energy Technology Data Exchange (ETDEWEB)

    Chang, Yan-Tyng.

    1991-11-01

    A simple empirical valence bond (EVB) model approach is suggested for constructing global potential energy surfaces for reactions of polyatomic molecular systems. This approach produces smooth and continuous potential surfaces which can be directly utilized in a dynamical study. Two types of reactions are of special interest, the unimolecular dissociation and the unimolecular isomerization. For the first type, the molecular dissociation dynamics of formaldehyde on the ground electronic surface is investigated through classical trajectory calculations on EVB surfaces. The product state distributions and vector correlations obtained from this study suggest very similar behaviors seen in the experiments. The intramolecular hydrogen atom transfer in the formic acid dimer is an example of the isomerization reaction. High level ab initio quantum chemistry calculations are performed to obtain optimized equilibrium and transition state dimer geometries and also the harmonic frequencies.

  18. An Optimization Framework for Dynamic Hybrid Energy Systems

    Energy Technology Data Exchange (ETDEWEB)

    Wenbo Du; Humberto E Garcia; Christiaan J.J. Paredis

    2014-03-01

    A computational framework for the efficient analysis and optimization of dynamic hybrid energy systems (HES) is developed. A microgrid system with multiple inputs and multiple outputs (MIMO) is modeled using the Modelica language in the Dymola environment. The optimization loop is implemented in MATLAB, with the FMI Toolbox serving as the interface between the computational platforms. Two characteristic optimization problems are selected to demonstrate the methodology and gain insight into the system performance. The first is an unconstrained optimization problem that optimizes the dynamic properties of the battery, reactor and generator to minimize variability in the HES. The second problem takes operating and capital costs into consideration by imposing linear and nonlinear constraints on the design variables. The preliminary optimization results obtained in this study provide an essential step towards the development of a comprehensive framework for designing HES.

  19. Consumption dynamics of primary-energy sources: The century of alternative energies

    Energy Technology Data Exchange (ETDEWEB)

    Oliveira Matias, Joao Carlos de; Devezas, Tessaleno Campos [Department of Electromechanical Engineering, University of Beira Interior, P-6201-001 Covilha (Portugal)

    2007-07-15

    The present article characterizes economically and socially the two past centuries, focusing the consumption development of several primary-energy sources, linking it with this century's reality. The main objective is to demonstrate the relationship between the substitution process of primary-energy sources and the socio-economic development. Our analysis focuses on four technological transformations that have already occurred, emphasizing some aspects of present technological transformations. Thus, the role of primary-energy sources in the development of each long economic wave is analysed, as well as its geopolitical, commercial and social importance. Finally, bearing in mind the past dynamics associated with long structural waves, and making use of technological forecasting tools (Logistic Substitution and Delphi Technique), a future perspective is presented in which the substitution process points toward alternative-energy sources. (author)

  20. Consumption dynamics of the primary energy sources. The Century of the alternative energies

    Energy Technology Data Exchange (ETDEWEB)

    Matias, Joao Carlos de Oliveira; Devezas, Tessaleno Campos [Dept. of Electromechanical Engineering, University of Beira Interior, Covilha (Portugal)

    2002-07-01

    The present article characterizes the two past centuries economically and socially, focusing on the development of the several energy sources' consumption and linking it with this century's reality. The central aim is to demonstrate the relation between substitution of primary energy sources and socio-economic development. Our analysis focuses four technological transformations already occurred in the past, emphasising some aspects of the present technological transformation. Thus, the role of primary energy sources on the development of each long wave is emphasized as well as their geopolitical, commercial and social importance. Finally, and keeping in mind this past dynamics associated with long structural waves, and making use of technological forecasting tools (Logistic Substitution and Delphi Technique), it is presented a future perspective in which the substitution process points towards alternative energy sources.

  1. Dynamics of energy systems: Methods of analysing technology change

    Energy Technology Data Exchange (ETDEWEB)

    Neij, Lena

    1999-05-01

    Technology change will have a central role in achieving a sustainable energy system. This calls for methods of analysing the dynamics of energy systems in view of technology change and policy instruments for effecting and accelerating technology change. In this thesis, such methods have been developed, applied, and assessed. Two types of methods have been considered, methods of analysing and projecting the dynamics of future technology change and methods of evaluating policy instruments effecting technology change, i.e. market transformation programmes. Two methods are focused on analysing the dynamics of future technology change; vintage models and experience curves. Vintage models, which allow for complex analysis of annual streams of energy and technological investments, are applied to the analysis of the time dynamics of electricity demand for lighting and air-distribution in Sweden. The results of the analyses show that the Swedish electricity demand for these purposes could decrease over time, relative to a reference scenario, if policy instruments are used. Experience curves are used to provide insight into the prospects of diffusion of wind turbines and photo voltaic (PV) modules due to cost reduction. The results show potential for considerable cost reduction for wind-generated electricity, which, in turn, could lead to major diffusion of wind turbines. The results also show that major diffusion of PV modules, and a reduction of PV generated electricity down to the level of conventional base-load electricity, will depend on large investments in bringing the costs down (through R D and D, market incentives and investments in niche markets) or the introduction of new generations of PV modules (e.g. high-efficiency mass-produced thin-film cells). Moreover, a model has been developed for the evaluation of market transformation programmes, i.e. policy instruments that effect technology change and the introduction and commercialisation of energy

  2. Secretary's annual report to Congress. Volume II. Budget highlights, 1982

    Energy Technology Data Exchange (ETDEWEB)

    None

    1981-01-01

    DOE budget requests for FY 1982 is summarized and then detailed. Budget highlights of the energy programs include: conservation; research, development, and applications (fossil energy, solar, electric energy and energy storage systems, magnetic fusion, nuclear fission, environment); regulation and energy information; direct energy production, and strategic petroleum reserves. Additional programs and their budget requests are given for: general science, defense activities, and departmental administration. The FY 1981 supplemental and recission request is indicated. Special budget analyses are given for Federal fossil, Federal solar, nuclear waste, conservation, and alternative fuels activities programs. The organizational table is presented. Extensive statistics are presented in the appendix. (MCW)

  3. Energy Dynamics of an Infinitely Large Offshore Wind Farm

    DEFF Research Database (Denmark)

    Frandsen, Sten Tronæs; Barthelmie, R.J.; Pryor, S.C.

    , particularly in the near-term, can be expected in the higher resource, moderate water depths of the North Sea rather than the Mediterranean. There should therefore be significant interest in understanding the energy dynamics of the infinitely large wind farm – how wakes behave and whether the extraction...... of energy by wind turbines over a large area has a significant and lasting impact on the atmospheric boundary layer. Here we focus on developing understanding of the infinite wind farm through a combination of theoretical considerations, data analysis and modeling. Initial evaluation of power losses due...... to wakes in the large Danish offshore wind farms at Horns Rev and Nysted indicated that losses were larger than expected. Temporary solutions have been found to account for this in wind farm models including use of an ‘added roughness’ block around the offshore wind farm. In the long-term however physical...

  4. Dynamics of energy harvesting backpack with human being interaction

    Science.gov (United States)

    Yuan, Yue; Zuo, Lei

    2016-04-01

    In last ten years, a lot of researchers have begun to look into obtaining electricity from the movement between human and their backpack that occurs during walking. In this paper, an innovative, elastically-suspended backpack with mechanical motion rectifier (MMR) based energy harvester is developed to generate electricity with high efficiency and reliability. Up to 28 Watts peak electrical power can be produced by the MMR based backpack energy harvester. A dynamic model for the system is presented along with experimental results. Three dual mass models for different distinct harvesters: pure viscous, non MMR, and MMR, are proposed, and a comparison in the output power and human comfort between the three models is discussed.

  5. Thermal energy storage for a space solar dynamic power system

    Science.gov (United States)

    Faget, N. M.; Fraser, W. M., Jr.; Simon, W. E.

    1985-01-01

    In the past, NASA has employed solar photovoltaic devices for long-duration missions. Thus, the Skylab system has operated with a silicon photovoltaic array and a nickel-cadmium electrochemical system energy storage system. Difficulties regarding the employment of such a system for the larger power requirements of the Space Station are related to a low orbit system efficiency and the large weight of the battery. For this reason the employment of a solar dynamic power system (SDPS) has been considered. The primary components of an SDPS include a concentrating mirror, a heat receiver, a thermal energy storage (TES) system, a thermodynamic heat engine, an alternator, and a heat rejection system. The heat-engine types under consideration are a Brayton cycle engine, an organic Rankine cycle engine, and a free-piston/linear-alternator Stirling cycle engine. Attention is given to a system description, TES integration concepts, and a TES technology assessment.

  6. Computing Equilibrium Free Energies Using Non-Equilibrium Molecular Dynamics

    Directory of Open Access Journals (Sweden)

    Christoph Dellago

    2013-12-01

    Full Text Available As shown by Jarzynski, free energy differences between equilibrium states can be expressed in terms of the statistics of work carried out on a system during non-equilibrium transformations. This exact result, as well as the related Crooks fluctuation theorem, provide the basis for the computation of free energy differences from fast switching molecular dynamics simulations, in which an external parameter is changed at a finite rate, driving the system away from equilibrium. In this article, we first briefly review the Jarzynski identity and the Crooks fluctuation theorem and then survey various algorithms building on these relations. We pay particular attention to the statistical efficiency of these methods and discuss practical issues arising in their implementation and the analysis of the results.

  7. The Trace Anomaly and Dynamical Vacuum Energy in Cosmology

    CERN Document Server

    Mottola, Emil

    2010-01-01

    The trace anomaly of conformal matter implies the existence of massless scalar poles in physical amplitudes involving the stress-energy tensor. These poles may be described by a local effective action with massless scalar fields, which couple to classical sources, contribute to gravitational scattering processes, and can have long range gravitational effects at macroscopic scales. In an effective field theory approach, the effective action of the anomaly is an infrared relevant term that should be added to the Einstein-Hilbert action of classical General Relativity to take account of macroscopic quantum effects. The additional scalar degrees of freedom contained in this effective action may be understood as responsible for both the Casimir effect in flat spacetime and large quantum backreaction effects at the horizon scale of cosmological spacetimes. These effects of the trace anomaly imply that the cosmological vacuum energy is dynamical, and its value depends on macroscopic boundary conditions at the cosmol...

  8. Using energetic budgets to assess the effects of environmental stress on corals: are we measuring the right things?

    Science.gov (United States)

    Lesser, M. P.

    2013-03-01

    Historically, the response of marine invertebrates to their environment, and environmentally induced stress, has included some measurement of their physiology or metabolism. Eventually, this approach developed into comparative energetics and the construction of energetic budgets. More recently, coral reefs, and scleractinian corals in particular, have suffered significant declines due to climate change-related environmental stress. In addition to a number of physiological, biophysical and molecular measurements to assess "coral health," there has been increased use of energetic approaches that have included the measurement of specific biochemical constituents (i.e., lipid concentrations) as a proxy for energy available to assess the potential outcomes of environmental stress on corals. In reading these studies, there appears to be some confusion between energy budgets and carbon budgets. Additionally, many assumptions regarding proximate biochemical composition, metabolic fuel preferences and metabolic quotients have been made, all of which are essential to construct accurate energy budgets and to convert elemental composition (i.e., carbon) to energy equivalents. Additionally, models of energetics such as the metabolic theory of ecology or dynamic energy budgets are being applied to coral physiology and include several assumptions that are not appropriate for scleractinian corals. As we assess the independent and interactive effects of multiple stressors on corals, efforts to construct quantitative energetic budgets should be a priority component of realistic multifactor experiments that would then improve the use of models as predictors of outcomes related to the effects of environmental change on corals.

  9. Building a field- and model-based climatology of local water and energy cycles in the cultivated Sahel - annual budgets and seasonality

    Science.gov (United States)

    Velluet, C.; Demarty, J.; Cappelaere, B.; Braud, I.; Issoufou, H. B.-A.; Boulain, N.; Ramier, D.; Mainassara, I.; Charvet, G.; Boucher, M.; Chazarin, J.-P.; Oï, M.; Yahou, H.; Maidaji, B.; Arpin-Pont, F.; Benarrosh, N.; Mahamane, A.; Nazoumou, Y.; Favreau, G.; Seghieri, J.

    2014-12-01

    In the sub-Saharan Sahel, energy and water cycling at the land surface is pivotal for the regional climate, water resources and land productivity, yet it is still very poorly documented. As a step towards a comprehensive climatological description of surface fluxes in this area, this study provides estimates of long-term average annual budgets and seasonal cycles for two main land use types of the cultivated Sahelian belt: rainfed millet crop and fallow bush. These estimates build on the combination of a 7-year field data set from two typical plots in southwestern Niger with detailed physically based soil-plant-atmosphere modeling, yielding a continuous, comprehensive set of water and energy flux and storage variables over this multiyear period. In the present case in particular, blending field data with mechanistic modeling makes the best use of available data and knowledge for the construction of the multivariate time series. Rather than using the model only to gap-fill observations into a composite series, model-data integration is generalized homogeneously over time by generating the whole series with the entire data-constrained model simulation. Climatological averages of all water and energy variables, with associated sampling uncertainty, are derived at annual to sub-seasonal scales from the time series produced. Similarities and differences in the two ecosystem behaviors are highlighted. Mean annual evapotranspiration is found to represent ~82-85% of rainfall for both systems, but with different soil evaporation/plant transpiration partitioning and different seasonal distribution. The remainder consists entirely of runoff for the fallow, whereas drainage and runoff stand in a 40-60% proportion for the millet field. These results should provide a robust reference for the surface energy- and water-related studies needed in this region. Their significance and the benefits they gain from the innovative data-model integration approach are thoroughly discussed

  10. Evolution of the Granular Dynamics and Energy Transport

    Science.gov (United States)

    Nesis, A.; Hammer, R.; Schleicher, H.

    2003-05-01

    Based on series of excellent spectrograms taken at the German Vacuum Tower Telescope (VTT) at the Observatorio del Teide (Tenerife), we study the temporal evolution of the granular dynamics and the energy transport in the photospheric layers. We consider the ensemble of the granules cut by the spectrograph slit as a complex system. We describe this ensemble by the rms of the fluctuations of the granular observables along the slit: continuum intensity I, Doppler velocity v, and line width w. The history of the rms of the observables v and w reflects the dynamical change of the system over the 20 minutes observation time. We find for both observables a quasi-periodical change. However, the history of the cross-correlation between I and v remains virtually constant, with the exception of two gaps. We measure the rms of v in the deep photospheric layers for six lines of different strength included in the spectrograms. Using a model velocity variation based on our previous publications, we assign photospheric heights to the velocity measurements. These heights agree with those calculated by other means. On the basis of this v variation we calculate the kinetic energy flux as a function of the height in the photosphere for different times during the observation. The form of the variation with height turns out to be constant in time. The convective energy flux, finally, is calculated from the measured velocity and the temperature variations of our earlier models. Again we find practically the same variation form over the time of the observation. Taken together, these results quantify the different roles that the lower and higher photospheric layers play for the energetics of the convective overshoot at the upper boundary of the superadiabatic region of the Sun. A.N. acknowledges travel support from the German science foundation DFG.

  11. Mean kinetic energy transport and event classification in a model wind turbine array versus an array of porous disks: Energy budget and octant analysis

    Science.gov (United States)

    Camp, Elizabeth H.; Cal, Raúl Bayoán

    2016-08-01

    An array of model rotating wind turbines is compared experimentally to an array of static porous disks in order to quantify the similarities and differences in the mean kinetic energy transport within the wakes produced in these two cases. Stereo particle image velocimetry measurements are done in a wind tunnel bracketing the center turbine in the fourth row of a 4 ×3 array of model turbines. Equivalent sets of rotors and porous disks are created by matching their respective induction factors. The primary difference in the mean velocity components is found in the spanwise mean velocity component, which is as much as 190% different between the rotor and disk case. Horizontal averages of mean kinetic energy transport terms in the region where rotation is most important show percent differences in the range 3%-41%, which decrease to 1%-6% at streamwise coordinates where rotation is less important. Octant analysis is performed on the most significant term related to vertical mean kinetic energy flux u'v' ¯U . The average percent difference between corresponding octants is as much as 68% different in the near wake and as much as 17% different in the far wake. Furthermore, octant analysis elucidates the three-dimensional nature of sweeps and ejections in the near wake of the rotor case. Together, these results imply that a stationary porous disk adequately represents the mean kinetic energy transport of a rotor in the far wake where rotation is less important, while significant discrepancies exist at streamwise locations where rotation is a key phenomenon. This comparison has implications in the use of an actuator disk to model the wind turbine rotor in computational simulations specifically for studies where Reynolds stresses, turbulence intensity, or interactions with the atmosphere are of interest.

  12. Verification of uncertainty budgets

    DEFF Research Database (Denmark)

    Heydorn, Kaj; Madsen, B.S.

    2005-01-01

    The quality of analytical results is expressed by their uncertainty, as it is estimated on the basis of an uncertainty budget; little effort is, however, often spent on ascertaining the quality of the uncertainty budget. The uncertainty budget is based on circumstantial or historical data, and th...

  13. Federal budget timetable

    Science.gov (United States)

    This is the federal budget timetable under the Balanced Budget and Emergency Deficit Control Act of 1985 (Gramm-Rudman-Hollings). These deadlines apply to fiscal years (FY) 1987-1991. The deficit reduction measures in Gramm-Rudman-Hollings would lead to a balanced budget in 1991.

  14. Energy budgets and transports: global evolution and spatial patterns during the twentieth century as estimated in two AMIP-like experiments

    Science.gov (United States)

    Lembo, Valerio; Folini, Doris; Wild, Martin; Lionello, Piero

    2017-03-01

    This study describes characteristics and evolution of the residual of the Earth energy budget (EB) individual components and the implied meridional transports during the twentieth century. This analysis considers two ensembles of AMIP-like experiments (Atmospheric Model Intercomparison Project) with prescribed evolution of sea surface temperature and sea ice concentration (SST-SIC), greenhouse gases (GHG), anthropogenic and volcanic aerosols over the entire twentieth century: ERA-20CM and ECHAM5-HAM model simulations. With the latter, additional sensitivity experiments are carried out by constraining either SST-SIC or aerosols to climatological values. The two models provide compatible estimates of the EBs and implied transport absolute values in recent decades. They are not in agreement in terms of global scale evolution: in the 1970s ERA-20CM shows a fast transition from negative to positive EBs at top of atmosphere (TOA) that is not found in ECHAM5-HAM. Climatological SST-SIC sensitivity experiments evidence that the aerosol forcing affects TOA and surface EBs by setting up an inter-hemispheric gradient after 1960. This is also reflected by an increased total transport in the Northern Hemisphere, while decreased in the Southern Hemisphere. ERA-20CM shows no evidence of a similar aerosol forcing. Sensitivity experiments with fixed pre-industrial aerosols show that transient SST are responsible for irregular spatio-temporal anomalies of surface and atmospheric EBs and transports. Surface and atmospheric anomalies oppose each other, and transient SSTs do not influence the EB changes at TOA. Impact of transient SST and GHG forcing on EBs and implied transports are robust across the two models.

  15. Evaluating the effects of historical land cover change on summertime weather and climate in New Jersey: Land cover and surface energy budget changes

    Science.gov (United States)

    Wichansky, P.S.; Steyaert, L.T.; Walko, R.L.; Waever, C.P.

    2008-01-01

    The 19th-century agrarian landscape of New Jersey (NJ) and the surrounding region has been extensively transformed to the present-day land cover by urbanization, reforestation, and localized areas of deforestation. This study used a mesoscale atmospheric numerical model to investigate the sensitivity of the warm season climate of NJ to these land cover changes. Reconstructed 1880s-era and present-day land cover data sets were used as surface boundary conditions for a set of simulations performed with the Regional Atmospheric Modeling System (RAMS). Three-member ensembles with historical and present-day land cover were compared to examine the sensitivity of surface air and dew point temperatures, rainfall, and the individual components of the surface energy budget to these land cover changes. Mean temperatures for the present-day landscape were 0.3-0.6??C warmer than for the historical landscape over a considerable portion of NJ and the surrounding region, with daily maximum temperatures at least 1.0??C warmer over some of the highly urbanized locations. Reforested regions, however, were slightly cooler. Dew point temperatures decreased by 0.3-0.6??C, suggesting drier, less humid near-surface air for the present-day landscape. Surface warming was generally associated with repartitioning of net radiation from latent to sensible heat flux, and conversely for cooling. While urbanization was accompanied by strong surface albedo decreases and increases in net shortwave radiation, reforestation and potential changes in forest composition have generally increased albedos and also enhanced landscape heterogeneity. The increased deciduousness of forests may have further reduced net downward longwave radiation. Copyright 2008 by the American Geophysical Union.

  16. Energy budgets and transports: global evolution and spatial patterns during the twentieth century as estimated in two AMIP-like experiments

    Science.gov (United States)

    Lembo, Valerio; Folini, Doris; Wild, Martin; Lionello, Piero

    2016-05-01

    This study describes characteristics and evolution of the residual of the Earth energy budget (EB) individual components and the implied meridional transports during the twentieth century. This analysis considers two ensembles of AMIP-like experiments (Atmospheric Model Intercomparison Project) with prescribed evolution of sea surface temperature and sea ice concentration (SST-SIC), greenhouse gases (GHG), anthropogenic and volcanic aerosols over the entire twentieth century: ERA-20CM and ECHAM5-HAM model simulations. With the latter, additional sensitivity experiments are carried out by constraining either SST-SIC or aerosols to climatological values. The two models provide compatible estimates of the EBs and implied transport absolute values in recent decades. They are not in agreement in terms of global scale evolution: in the 1970s ERA-20CM shows a fast transition from negative to positive EBs at top of atmosphere (TOA) that is not found in ECHAM5-HAM. Climatological SST-SIC sensitivity experiments evidence that the aerosol forcing affects TOA and surface EBs by setting up an inter-hemispheric gradient after 1960. This is also reflected by an increased total transport in the Northern Hemisphere, while decreased in the Southern Hemisphere. ERA-20CM shows no evidence of a similar aerosol forcing. Sensitivity experiments with fixed pre-industrial aerosols show that transient SST are responsible for irregular spatio-temporal anomalies of surface and atmospheric EBs and transports. Surface and atmospheric anomalies oppose each other, and transient SSTs do not influence the EB changes at TOA. Impact of transient SST and GHG forcing on EBs and implied transports are robust across the two models.

  17. Using energy budget data to assess the most damaging life-stage of an agricultural pest Mocis latipes (Guenèe, 1982 (Lepidoptera - Noctuidae

    Directory of Open Access Journals (Sweden)

    MJT. Assunção-Albuquerque

    Full Text Available There is much evidence to support that Mocis latipes larvae (Guenèe, 1852 are the most dangerous pasture pest and usually cause large environmental losses. However, no studies have been carried out to identify the instars during which this moth causes the most damage to the environment. Here we calculate M. latipes larval energy budget to assess its consumption across all instars and estimate the consumption/amount of plant biomass required to complete its larval development. Assimilation, respiration, consumption, excretion, gross growth efficiency and net growth efficiency were calculated. Pearson correlations were used to identify the best predictors that influenced larval growth and weight. Across all instars consumption increased exponentially, especially during the last phase. M. latipes larvae consumed ca 13.8% of total food from the first to the fifth instar, whereas during the sixth instars these larvae consumed ca 72.6%. Results also show that the best gross growth and net growth efficiency were obtained when larvae reached the fifth instar. The results also show that one larva of Mocis latipes consumes 1.02 g (dry weight of Paspalum maritimum (Trin in 19 days. Overall, our results indentified the sixth instar as the most destructive instar of this insect. Thus, once we know the most destructive instars of this pest, measures can be taken to disable M. latipes larval development and consequently stop their increase in plant consumption, reducing ecological and economic damage. This knowledge may eventually lead to reduced agricultural damage and contribute to sustainable farming strategies.

  18. Assessing Numerical Error in Structural Dynamics Using Energy Balance

    Directory of Open Access Journals (Sweden)

    Rabindranath Andujar

    2013-01-01

    Full Text Available This work applies the variational principles of Lagrange and Hamilton to the assessment of numerical methods of linear structural analysis. Different numerical methods are used to simulate the behaviour of three structural configurations and benchmarked in their computation of the Lagrangian action integral over time. According to the principle of energy conservation, the difference at each time step between the kinetic and the strain energies must equal the work done by the external forces. By computing this difference, the degree of accuracy of each combination of numerical methods can be assessed. Moreover, it is often difficult to perceive numerical instabilities due to the inherent complexities of the modelled structures. By means of the proposed procedure, these complexities can be globally controlled and visualized in a straightforward way. The paper presents the variational principles to be considered for the collection and computation of the energy-related parameters (kinetic, strain, dissipative, and external work. It then introduces a systematic framework within which the numerical methods can be compared in a qualitative as well as in a quantitative manner. Finally, a series of numerical experiments is conducted using three simple 2D models subjected to the effect of four different dynamic loadings.

  19. Political Budget Cycles in the European Union

    Directory of Open Access Journals (Sweden)

    Jiří Gregor

    2016-01-01

    Full Text Available This paper provides research on the theme of the political budget cycles. The goal is to find out whether or not the government tries to manipulate the state budget and its components for the purpose of re-election across the countries of the European Union. In order to verify this theory a dynamic panel data model was used. The results were significant, but only if predetermined elections were not counted into the estimations. In that case, the theory of the political budget cycles could be accepted as valid for the EU countries. The main driving force of the political budget cycles across the countries of the European Union is fluctuation of the government expenditures. During the election year, the government expenditures are higher, and a year after the election, government expenditures are lower. This is reflected into the state budget balance.

  20. Nonlinear analysis and dynamic structure in the energy market

    Science.gov (United States)

    Aghababa, Hajar

    This research assesses the dynamic structure of the energy sector of the aggregate economy in the context of nonlinear mechanisms. Earlier studies have focused mainly on the price of the energy products when detecting nonlinearities in time series data of the energy market, and there is little mention of the production side of the market. Moreover, there is a lack of exploration about the implication of high dimensionality and time aggregation when analyzing the market's fundamentals. This research will address these gaps by including the quantity side of the market in addition to the price and by systematically incorporating various frequencies for sample sizes in three essays. The goal of this research is to provide an inclusive and exhaustive examination of the dynamics in the energy markets. The first essay begins with the application of statistical techniques, and it incorporates the most well-known univariate tests for nonlinearity with distinct power functions over alternatives and tests different null hypotheses. It utilizes the daily spot price observations on five major products in the energy market. The results suggest that the time series daily spot prices of the energy products are highly nonlinear in their nature. They demonstrate apparent evidence of general nonlinear serial dependence in each individual series, as well as nonlinearity in the first, second, and third moments of the series. The second essay examines the underlying mechanism of crude oil production and identifies the nonlinear structure of the production market by utilizing various monthly time series observations of crude oil production: the U.S. field, Organization of the Petroleum Exporting Countries (OPEC), non-OPEC, and the world production of crude oil. The finding implies that the time series data of the U.S. field, OPEC, and the world production of crude oil exhibit deep nonlinearity in their structure and are generated by nonlinear mechanisms. However, the dynamics of the non

  1. Modeling energy market dynamics using discrete event system simulation

    Energy Technology Data Exchange (ETDEWEB)

    Gutierrez-Alcaraz, G. [Department of Electrical and Electronics Engineering, Instituto Tecnologico de Morelia, Av. Tecnologico 1500, Col. Lomas de Santiaguito 58120, Morelia Michoacan (Mexico); Sheble, G.B. [Department of Electrical and Computer Engineering, Portland State University, Portland, OR 97207-0751 (United States)

    2009-10-15

    This paper proposes the use of Discrete Event System Simulation to study the interactions among fuel and electricity markets and consumers, and the decision-making processes of fuel companies (FUELCOs), generation companies (GENCOs), and consumers in a simple artificial energy market. In reality, since markets can reach a stable equilibrium or fail, it is important to observe how they behave in a dynamic framework. We consider a Nash-Cournot model in which marketers are depicted as Nash-Cournot players that determine supply to meet end-use consumption. Detailed engineering considerations such as transportation network flows are omitted, because the focus is upon the selection and use of appropriate market models to provide answers to policy questions. (author)

  2. Dynamical dark energy: scalar fields and running vacuum

    CERN Document Server

    Sola, Joan; Perez, Javier de Cruz

    2016-01-01

    Recent analyses in the literature suggest that the concordance $\\Lambda$CDM model with rigid cosmological term, $\\Lambda=$const., may not be the best description of the cosmic acceleration. The class of "running vacuum models", in which $\\Lambda=\\Lambda(H)$ evolves with the Hubble rate, has been shown to fit the string of $SNIa+BAO+H(z)+LSS+CMB$ data significantly better than the $\\Lambda$CDM. Here we provide further evidence on the time-evolving nature of the dark energy (DE) by fitting the same cosmological data in terms of scalar fields. As a representative model we use the original Peebles & Ratra potential, $V\\propto\\Phi^{-\\alpha}$. We find clear signs of dynamical DE at $\\sim 4\\sigma$ c.l., thus reconfirming through a nontrivial scalar field approach the strong hints formerly found with other models and parametrizations.

  3. Dynamics of secondary ion emission: Novel energy and angular spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    Jalowy, T. E-mail: jalowy@hsb.uni-frankfurt.de; Neugebauer, R.; Hattass, M.; Fiol, J.; Afaneh, F.; Pereira, J.A.M.; Collado, V.; Silveira, E.F. da; Schmidt-Boecking, H.; Groeneveld, K.O

    2002-06-01

    A new spectrometer has been developed based on the combination of standard time-of-flight technique and position sensitive delay line detectors. The basic features of the spectrometer, particularly of the multi-hit capable detector, are described. To demonstrate the performance of this new system, the dynamic emission characteristics, i.e. the three-dimensional velocity distribution, of desorbed H{sub 2}{sup +} from Al target by Ar{sup 0} impact (570 keV) is presented. It is found that the desorption yield is maximum for radial and axial emission velocities at 1.2 and 12 km/s respectively, corresponding to 1.5 eV ions emitted at 57 deg. to normal (following the projectile radial direction). The initial energy distribution spreads out over 16 eV.

  4. Particle physics and dark energy. Beyond classical dynamics

    Energy Technology Data Exchange (ETDEWEB)

    Garny, Mathias

    2008-10-24

    In this work, quantum corrections to classical equations of motion are investigated for dynamical models of dark energy featuring a time-evolving quintessence scalar field. Employing effective quantum field theory, the robustness of tracker quintessence potentials against quantum corrections as well as their impact on cosmological observables are discussed. Furthermore, it is demonstrated that a rolling quintessence field can also play an important role for baryogenesis in the early universe. The macroscopic time-evolution of scalar quantum fields can be described from first principles within nonequilibrium quantum field theory based on Kadanoff-Baym equations derived from the 2PI effective action. A framework for the nonperturbative renormalization of Kadanoff-Baym equations is provided. Renormalized Kadanoff-Baym equations are proposed and their finiteness is shown for a special case. (orig.)

  5. Dynamics of secondary ion emission Novel energy and angular spectrometry

    CERN Document Server

    Jalowy, T; Hattass, M; Fiol, J; Afaneh, F; Pereira, J A M; Collado, V; Silveira, E F D; Schmidt-Böcking, H; Groeneveld, K O

    2002-01-01

    A new spectrometer has been developed based on the combination of standard time-of-flight technique and position sensitive delay line detectors. The basic features of the spectrometer, particularly of the multi-hit capable detector, are described. To demonstrate the performance of this new system, the dynamic emission characteristics, i.e. the three-dimensional velocity distribution, of desorbed H sub 2 sup + from Al target by Ar sup 0 impact (570 keV) is presented. It is found that the desorption yield is maximum for radial and axial emission velocities at 1.2 and 12 km/s respectively, corresponding to 1.5 eV ions emitted at 57 deg. to normal (following the projectile radial direction). The initial energy distribution spreads out over 16 eV.

  6. Composite charged particle detectors with logarithmic energy response for large dynamic range energy measurements

    Energy Technology Data Exchange (ETDEWEB)

    Fowler, M.M.; Begemann-Blaich, M.L.; Blaich, T.; Boissevain, J.A.; Gavron, A.; Jacak, B.V.; Lysaght, P.S.; Wilhelmy, J.B. (Los Alamos National Lab., NM (USA)); Sangster, T.C.; Britt, H.C.; Fields, D.J.; Lanier, R.G.; Massoletti, D.J.; Namboodiri, M.N. (Lawrence Livermore National Lab., CA (USA)); Chan, Y.D.; Harmon, A.; Pouliot, J.; Stokstad, R.G. (Lawrence Berkeley Lab., CA (USA)); Dacal, A. (Universidad Nacional Autonoma de Mexico, Mexico City. Inst. de Fisica); Fraenkel, Z.; Mamane, G. (Weizmann Inst. of Science, Rehovoth (Israel)); Webb, M.L. (Dynamics Technology, Inc., Torrance, CA (USA))

    1989-09-15

    We have developed an array of detectors to identify charged particles produced in heavy ion reactions. The array, which consists of eight individual detector modules and a forward hodoscope, subtends a solid angle of 0.58{pi} and covers 62% of the reaction plane in laboratory coordinates. Each of the eight identical modules has an active area which extends 13{sup 0} above and below the array plane with additional limited coverage between 13{sup 0} and 26{sup 0}. Each module measures the position, energy and velocity of charged particles over a dynamic range which extends from minium ionizing protons with energies up to 200 MeV to highly ionizing fission fragments with Coulomb-like energies. Position and time-of-flight are measured with low pressure multiwire proprotional counters (MWPC). Total energies for heavier ions are obtained from large ion chambers. Energy and position measurements for more energetic lighter ions which pass through the ion chambers are made with segmented phoswich arrays. The forward angle hodoscope is a 34-element array of phoswich detectors mounted symmetrically around the beam axis. These detectors are sensitive to beam velocity particles (E/A > 10-40 MeV/A) and capable of elemental resolution from protons to Z = 23. (orig.).

  7. The impact of wind energy turbine piles on ocean dynamics

    Science.gov (United States)

    Grashorn, Sebastian; Stanev, Emil V.

    2016-04-01

    The small- and meso-scale ocean response to wind parks has not been investigated in the southern North Sea until now with the help of high-resolution numerical modelling. Obstacles such as e.g. wind turbine piles may influence the ocean current system and produce turbulent kinetic energy which could affect sediment dynamics in the surrounding area. Two setups of the unstructured-grid model SCHISM (Semi-implicit Cross-scale Hydroscience Integrated System Model) have been developed for an idealized channel including a surface piercing cylindrical obstacle representing the pile and a more realistic test case including four exemplary piles. Experiments using a constant flow around the obstacles and a rotating M2 tidal wave are carried out. The resulting current and turbulence patterns are investigated to estimate the influence of the obstacles on the surrounding ocean dynamics. We demonstrate that using an unstructured ocean model provides the opportunity to embed a high-resolution representation of a wind park turbine pile system into a coarser North Sea setup, which is needed in order to perform a seamless investigation of the resulting geophysical processes.

  8. Elucidating energy and electron transfer dynamics within molecular assemblies for solar energy conversion

    Science.gov (United States)

    Morseth, Zachary Aaron

    The use of sunlight to make chemical fuels (i.e. solar fuels) is an attractive approach in the quest to develop sustainable energy sources. Using nature as a guide, assemblies for artificial photosynthesis will need to perform multiple functions. They will need to be able to harvest light across a broad region of the solar spectrum, transport excited-state energy to charge-separation sites, and then transport and store redox equivalents for use in the catalytic reactions that produce chemical fuels. This multifunctional behavior will require the assimilation of multiple components into a single macromolecular system. A wide variety of different architectures including porphyrin arrays, peptides, dendrimers, and polymers have been explored, with each design posing unique challenges. Polymer assemblies are attractive due to their relative ease of production and facile synthetic modification. However, their disordered nature gives rise to stochastic dynamics not present in more ordered assemblies. The rational design of assemblies requires a detailed understanding of the energy and electron transfer events that follow light absorption, which can occur on timescales ranging from femtoseconds to hundreds of microseconds, necessitating the use of sophisticated techniques. We have used a combination of time-resolved absorption and emission spectroscopies with observation times that span nine orders of magnitude to follow the excited-state evolution within single-site and polymer-based molecular assemblies. We complement experimental observations with electronic structure calculations, molecular dynamics simulations, and kinetic modeling to develop a microscopic view of these dynamics. This thesis provides an overview of work on single-site molecular assemblies and polymers decorated with pendant chromophores, both in solution and on surfaces. This work was made possible through extensive collaboration with Dr. Kirk Schanze's and Dr. John Reynolds' research groups who

  9. The trace anomaly and dynamical vacuum energy in cosmology

    Energy Technology Data Exchange (ETDEWEB)

    Mottola, Emil [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2010-04-30

    The trace anomaly of conformal matter implies the existence of massless scalar poles in physical amplitudes involving the stress-energy tensor. These poles may be described by a local effective action with massless scalar fields, which couple to classical sources, contribute to gravitational scattering processes, and can have long range gravitational effects at macroscopic scales. In an effective field theory approach, the effective action of the anomaly is an infrared relevant term that should be added to the Einstein-Hilbert action of classical General Relativity to take account of macroscopic quantum effects. The additional scalar degrees of freedom contained in this effective action may be understood as responsible for both the Casimir effect in flat spacetime and large quantum backreaction effects at the horizon scale of cosmological spacetimes. These effects of the trace anomaly imply that the cosmological vacuum energy is dynamical, and its value depends on macroscopic boundary conditions at the cosmological horizon scale, rather than sensitivity to the extreme ultraviolet Planck scale.

  10. Pion dynamics in nuclear collisions at SIS Energies

    Energy Technology Data Exchange (ETDEWEB)

    Senger, P. (Gesellschaft fuer Schwerionenforschung mbH, Darmstadt (Germany) Frankfurt Univ. (Germany) Marburg Univ. (Germany) Cracow Univ. (Poland)); KaoS Collaboration

    1993-01-01

    Heavy ion collisions at intermediate energies provide the unique possibility of investigating the properties of hot and compressed nuclear matter in the laboratory. According to microscopic transport calculations a baryon density of 2-3 [rho][sub o] can be reached for about 5 x 10[sup -23]s in a volume of approximately 100 fm[sup 3]. In order to extract information on nuclear matter properties from such a collision, the effects of the reaction dynamics on the experimental observables has to be understood. The most important dissipative process in a nuclear reaction around 1.0 GeV/u bombarding energy is the resonance excitation of nucleons, such as N N [yields] N [Delta] and N N [yields] N N*. The abundant baryonic resonances play a key role in the subthreshold production of particles like kaons, etas and antiprotons. With high probability these resonances decay by emitting pions as a reminder of a transient stage of hadronic matter. Therefore, pion production is a crucial test for theoretical models aiming to describe the reaction mechanism and subthreshold particle production. The high pion abundancy permits exploration of the space-time evolution of a nuclear collision. (author).

  11. Integrated inertial fusion energy chamber dynamics and response

    Energy Technology Data Exchange (ETDEWEB)

    Uddin, Hasib, E-mail: uddin3@illinois.edu [Department of Mechanical Science and Engineering, University of Illinois at Urbana–Champaign, Urbana, IL 61801 (United States); Kramer, Richard; Pantano, Carlos [Department of Mechanical Science and Engineering, University of Illinois at Urbana–Champaign, Urbana, IL 61801 (United States); Kramer, Kevin; Tang, Vincent [Lawrence Livermore National Laboratory, Livermore, CA 94550 (United States); Sacks, Ryan; Moses, Gregory [Fusion Technology Institute, University of Wisconsin Madison, Madison, WI 53706 (United States); Hunt, Ryan; DeMuth, James; Scott, Howard; Dunne, A. Mike [Lawrence Livermore National Laboratory, Livermore, CA 94550 (United States)

    2014-12-15

    Highlights: • LES with embedded geometry. • Repetitive IFE chamber state. • Sensitivity to blast modeling. - Abstract: This paper presents results of three-dimensional hydrodynamics simulations of the flow inside a model inertial fusion energy (IFE) fusion chamber. Turbulence modeling employing the large-eddy simulation approach is used to estimate the gas dynamics, state, and mixing after a sufficiently large number of target ignitions. The rich radiation-flow physics that takes place immediately after the lasers hit the hohlraum is modeled separately using a high-fidelity one-dimensional model, which provides reference conditions for the complex geometry three-dimensional turbulence simulations. The IFE geometry includes optical ports and recirculation openings as well as a duct to evacuate the debris produced after each energy deposition (as a model of a laser shot). Furthermore, a selected set of sensitivity studies are conducted to estimate the effect of uncertainty in radiative properties of the Xenon gas at the prevalent conditions in the chamber. The results provide guidance regarding the turbulence conditions in the chamber, which seem to have entered a decay state immediately before a new shot takes place. Computational estimates of the density variability within the chamber as well as pressure history at the approximate location of the laser optical ports is presented among other turbulence statistics.

  12. Self-balancing dynamic scheduling of electrical energy for energy-intensive enterprises

    Science.gov (United States)

    Gao, Yunlong; Gao, Feng; Zhai, Qiaozhu; Guan, Xiaohong

    2013-06-01

    Balancing production and consumption with self-generation capacity in energy-intensive enterprises has huge economic and environmental benefits. However, balancing production and consumption with self-generation capacity is a challenging task since the energy production and consumption must be balanced in real time with the criteria specified by power grid. In this article, a mathematical model for minimising the production cost with exactly realisable energy delivery schedule is formulated. And a dynamic programming (DP)-based self-balancing dynamic scheduling algorithm is developed to obtain the complete solution set for such a multiple optimal solutions problem. For each stage, a set of conditions are established to determine whether a feasible control trajectory exists. The state space under these conditions is partitioned into subsets and each subset is viewed as an aggregate state, the cost-to-go function is then expressed as a function of initial and terminal generation levels of each stage and is proved to be a staircase function with finite steps. This avoids the calculation of the cost-to-go of every state to resolve the issue of dimensionality in DP algorithm. In the backward sweep process of the algorithm, an optimal policy is determined to maximise the realisability of energy delivery schedule across the entire time horizon. And then in the forward sweep process, the feasible region of the optimal policy with the initial and terminal state at each stage is identified. Different feasible control trajectories can be identified based on the region; therefore, optimising for the feasible control trajectory is performed based on the region with economic and reliability objectives taken into account.

  13. Energy and thermal analysis of glazed office buildings using a dynamic energy simulation tool

    Energy Technology Data Exchange (ETDEWEB)

    Poirazis, H.; Blomsterberg, A. [Lund Inst. of Technology, Lund (Sweden). Div. of Energy and Building Design

    2005-07-01

    Although highly glazed buildings have more access to daylight than traditional buildings their energy efficiency is sometimes questionable. This paper presented energy and indoor climate simulations of single skin office buildings in Sweden with the use of a dynamic energy simulation tool. An analysis of building alternatives with 30, 60 and 100 per cent window areas were investigated. Parameters concerning the buildings' orientation, plan type, control set points and facade type were varied in the simulations. A virtual reference building was created as representative of Swedish office buildings constructed in the late 1990s. The design was determined by various Swedish agencies. Detailed performance specifications for energy and indoor climate were established and typical construction methods were determined. System descriptions and drawings were prepared. A validation of the simulated performance of the building showed that the performance specifications were accurate. A parametric study of energy use and indoor climate was conducted. Heating, ventilation and air conditioning (HVAC) systems and control systems were described in detail. Orientation, plan type, control set points, and facade elements were changed while other parameters such as the shape of the building and occupant activity levels remained the same. A sensitivity analysis was conducted regarding occupant comfort levels and the energy used for operating the building. It was concluded that the energy efficiency of a building depends on facade construction. It was suggested that highly glazed buildings will benefit through the use of advanced simulation tools during the design stage. It was also noted that the main aim when designing glazed buildings should be to avoid a high cooling demand. The impact of control set points on heating and cooling is also crucial for energy use, as well as the orientation of rooms. It was suggested that an increase in glazing area does not necessarily mean higher

  14. Water-budget methods

    Science.gov (United States)

    Healy, Richard W.; Scanlon, Bridget R.

    2010-01-01

    A water budget is an accounting of water movement into and out of, and storage change within, some control volume. Universal and adaptable are adjectives that reflect key features of water-budget methods for estimating recharge. The universal concept of mass conservation of water implies that water-budget methods are applicable over any space and time scales (Healy et al., 2007). The water budget of a soil column in a laboratory can be studied at scales of millimeters and seconds. A water-budget equation is also an integral component of atmospheric general circulation models used to predict global climates over periods of decades or more. Water-budget equations can be easily customized by adding or removing terms to accurately portray the peculiarities of any hydrologic system. The equations are generally not bound by assumptions on mechanisms by which water moves into, through, and out of the control volume of interest. So water-budget methods can be used to estimate both diffuse and focused recharge, and recharge estimates are unaffected by phenomena such as preferential flow paths within the unsaturated zone. Water-budget methods represent the largest class of techniques for estimating recharge. Most hydrologic models are derived from a water-budget equation and can therefore be classified as water-budget models. It is not feasible to address all water-budget methods in a single chapter. This chapter is limited to discussion of the “residual” water-budget approach, whereby all variables in a water-budget equation, except for recharge, are independently measured or estimated and recharge is set equal to the residual. This chapter is closely linked with Chapter 3, on modeling methods, because the equations presented here form the basis of many models and because models are often used to estimate individual components in water-budget studies. Water budgets for streams and other surface-water bodies are addressed in Chapter 4. The use of soil-water budgets and

  15. Energy of Long-Lifetime Configurations in Zero-Temperature Dynamics

    Institute of Scientific and Technical Information of China (English)

    RONG Yong-Hui; KONG Xiang-Mu

    2009-01-01

    Using Monte Carlo method with zero-temperature dynamics, we investigate energy evolution of Ising spin configuration on a square lattice.The energies of some configurations exhibit long duration before those configurations reach the final state -- ground state or frozen stripe state.For ground-state dynamical realization, the duration occurs when the energy per spin is 4/L, where L is the lattice size.For stripe-state dynamical realization, the energy is slightly higher than 2/ L when the duration appears in the last evolution stage.In addition, it is found that the average energy per spin in final state is approximately 2/3L.

  16. Demonstration Program for Low-Cost, High-Energy-Saving Dynamic Windows

    Science.gov (United States)

    2014-09-01

    Design The scope of this project was to demonstrate the impact of dynamic windows via energy savings and HVAC peak-load reduction; to validate the...dominated by the internal thermal loads of office equipment (example AC 7) so the HVAC energy savings are lower in those zones. Figure 8. Plot...of daily HVAC energy consumption in four representative zones, before and after dynamic windows retrofit. Overall, energy savings in all eastern

  17. Budget Summary of Changes

    Data.gov (United States)

    Pension Benefit Guaranty Corporation — The Summary of Changes dataset extracted from PBGC's congressional budget justification. It contains all administrative and program increases and decreases including...

  18. 7 CFR 3402.14 - Budget and budget narrative.

    Science.gov (United States)

    2010-01-01

    ... 7 Agriculture 15 2010-01-01 2010-01-01 false Budget and budget narrative. 3402.14 Section 3402.14 Agriculture Regulations of the Department of Agriculture (Continued) COOPERATIVE STATE RESEARCH, EDUCATION... budget narrative. Applicants must prepare the Budget, Form CSREES-2004, and a budget...

  19. Hydro-Gravitational Dynamics of Planets and Dark Energy

    Directory of Open Access Journals (Sweden)

    Carl H. Gibson

    2009-01-01

    Full Text Available Self gravitational fluid mechanical methods termed hydro-gravitational-dynamics (HGD predict plasma fragmentation 0.03 Myr after the turbulent big bang to form protosuperclustervoids, turbulent protosuperclusters, and protogalaxies at the 0.3 Myr transition from plasma to gas. Linear protogalaxyclusters fragment at 0.003 Mpc viscous-inertial scales along turbulent vortex lines or in spirals, as observed. The plasma protogalaxies fragment on transition into white-hot planet-mass gas clouds (PFPs in million-solar-mass clumps (PGCs that become globular-star-clusters (GCs from tidal forces or dark matter (PGCs by freezing and diffusion into 0.3 Mpc halos with 97% of the galaxy mass. The weakly collisional non-baryonic dark matter diffuses to > Mpc scales and fragments to form galaxy cluster halos. Stars and larger planets form by binary mergers of the trillion PFPs per PGC, mostly on 0.03 Mpc galaxy accretion disks. Stars deaths depend on rates of planet accretion and internal star mixing. Moderate accretion rates pro-duce white dwarfs that evaporate surrounding gas planets by spin-radiation to form planetary nebulae before Supernova Ia events, dimming some events to give systematic distance errors, the dark energy hypothesis, and overestimates of the universe age.

  20. Exploring the free energy surface using ab initio molecular dynamics

    Science.gov (United States)

    Samanta, Amit; Morales, Miguel A.; Schwegler, Eric

    2016-04-01

    Efficient exploration of configuration space and identification of metastable structures in condensed phase systems are challenging from both computational and algorithmic perspectives. In this regard, schemes that utilize a set of pre-defined order parameters to sample the relevant parts of the configuration space [L. Maragliano and E. Vanden-Eijnden, Chem. Phys. Lett. 426, 168 (2006); J. B. Abrams and M. E. Tuckerman, J. Phys. Chem. B 112, 15742 (2008)] have proved useful. Here, we demonstrate how these order-parameter aided temperature accelerated sampling schemes can be used within the Born-Oppenheimer and the Car-Parrinello frameworks of ab initio molecular dynamics to efficiently and systematically explore free energy surfaces, and search for metastable states and reaction pathways. We have used these methods to identify the metastable structures and reaction pathways in SiO2 and Ti. In addition, we have used the string method [W. E, W. Ren, and E. Vanden-Eijnden, Phys. Rev. B 66, 052301 (2002); L. Maragliano et al., J. Chem. Phys. 125, 024106 (2006)] within the density functional theory to study the melting pathways in the high pressure cotunnite phase of SiO2 and the hexagonal closed packed to face centered cubic phase transition in Ti.

  1. Energy Conservation Using Dynamic Voltage Frequency Scaling for Computational Cloud

    Directory of Open Access Journals (Sweden)

    A. Paulin Florence

    2016-01-01

    Full Text Available Cloud computing is a new technology which supports resource sharing on a “Pay as you go” basis around the world. It provides various services such as SaaS, IaaS, and PaaS. Computation is a part of IaaS and the entire computational requests are to be served efficiently with optimal power utilization in the cloud. Recently, various algorithms are developed to reduce power consumption and even Dynamic Voltage and Frequency Scaling (DVFS scheme is also used in this perspective. In this paper we have devised methodology which analyzes the behavior of the given cloud request and identifies the associated type of algorithm. Once the type of algorithm is identified, using their asymptotic notations, its time complexity is calculated. Using best fit strategy the appropriate host is identified and the incoming job is allocated to the victimized host. Using the measured time complexity the required clock frequency of the host is measured. According to that CPU frequency is scaled up or down using DVFS scheme, enabling energy to be saved up to 55% of total Watts consumption.

  2. Energy Conservation Using Dynamic Voltage Frequency Scaling for Computational Cloud.

    Science.gov (United States)

    Florence, A Paulin; Shanthi, V; Simon, C B Sunil

    2016-01-01

    Cloud computing is a new technology which supports resource sharing on a "Pay as you go" basis around the world. It provides various services such as SaaS, IaaS, and PaaS. Computation is a part of IaaS and the entire computational requests are to be served efficiently with optimal power utilization in the cloud. Recently, various algorithms are developed to reduce power consumption and even Dynamic Voltage and Frequency Scaling (DVFS) scheme is also used in this perspective. In this paper we have devised methodology which analyzes the behavior of the given cloud request and identifies the associated type of algorithm. Once the type of algorithm is identified, using their asymptotic notations, its time complexity is calculated. Using best fit strategy the appropriate host is identified and the incoming job is allocated to the victimized host. Using the measured time complexity the required clock frequency of the host is measured. According to that CPU frequency is scaled up or down using DVFS scheme, enabling energy to be saved up to 55% of total Watts consumption.

  3. The Analysis of the Development Dynamics and Structural Balance of Solar Energy in the World

    Science.gov (United States)

    Brand, A. E.; Chekardovskiy, S. M.; Akulov, K. A.

    2017-01-01

    The paper presents data the analysis of the development dynamics and structural balance of solar energy in the world. In the article presents information about total installed production capacity of solar energy, the world solar energy production capacity distribution and the European Union energy market structure in 2000 and 2015 years.

  4. Kinetic Energy-Based Temperature Computation in Non-Equilibrium Molecular Dynamics Simulation

    OpenAIRE

    Liu, Bin; Xu, Ran; He, Xiaoqiao

    2009-01-01

    The average kinetic energy is widely used to characterize temperature in molecular dynamics (MD) simulation. In this letter, the applicability of three types of average kinetic energy as measures of temperature is investigated, i.e., the total kinetic energy, kinetic energy without the centroid translation part, and thermal disturbance kinetic energy. Our MD simulations indicate that definitions of temperature based on the kinetic energy including rigid translational or rotational motion may ...

  5. Dynamic Voltage-Frequency and Workload Joint Scaling Power Management for Energy Harvesting Multi-Core WSN Node SoC

    Science.gov (United States)

    Li, Xiangyu; Xie, Nijie; Tian, Xinyue

    2017-01-01

    This paper proposes a scheduling and power management solution for energy harvesting heterogeneous multi-core WSN node SoC such that the system continues to operate perennially and uses the harvested energy efficiently. The solution consists of a heterogeneous multi-core system oriented task scheduling algorithm and a low-complexity dynamic workload scaling and configuration optimization algorithm suitable for light-weight platforms. Moreover, considering the power consumption of most WSN applications have the characteristic of data dependent behavior, we introduce branches handling mechanism into the solution as well. The experimental result shows that the proposed algorithm can operate in real-time on a lightweight embedded processor (MSP430), and that it can make a system do more valuable works and make more than 99.9% use of the power budget. PMID:28208730

  6. Dynamic Voltage-Frequency and Workload Joint Scaling Power Management for Energy Harvesting Multi-Core WSN Node SoC

    Directory of Open Access Journals (Sweden)

    Xiangyu Li

    2017-02-01

    Full Text Available This paper proposes a scheduling and power management solution for energy harvesting heterogeneous multi-core WSN node SoC such that the system continues to operate perennially and uses the harvested energy efficiently. The solution consists of a heterogeneous multi-core system oriented task scheduling algorithm and a low-complexity dynamic workload scaling and configuration optimization algorithm suitable for light-weight platforms. Moreover, considering the power consumption of most WSN applications have the characteristic of data dependent behavior, we introduce branches handling mechanism into the solution as well. The experimental result shows that the proposed algorithm can operate in real-time on a lightweight embedded processor (MSP430, and that it can make a system do more valuable works and make more than 99.9% use of the power budget.

  7. Dynamic Voltage-Frequency and Workload Joint Scaling Power Management for Energy Harvesting Multi-Core WSN Node SoC.

    Science.gov (United States)

    Li, Xiangyu; Xie, Nijie; Tian, Xinyue

    2017-02-08

    This paper proposes a scheduling and power management solution for energy harvesting heterogeneous multi-core WSN node SoC such that the system continues to operate perennially and uses the harvested energy efficiently. The solution consists of a heterogeneous multi-core system oriented task scheduling algorithm and a low-complexity dynamic workload scaling and configuration optimization algorithm suitable for light-weight platforms. Moreover, considering the power consumption of most WSN applications have the characteristic of data dependent behavior, we introduce branches handling mechanism into the solution as well. The experimental result shows that the proposed algorithm can operate in real-time on a lightweight embedded processor (MSP430), and that it can make a system do more valuable works and make more than 99.9% use of the power budget.

  8. Dynamic Behavior and Quasi-energy Spectrum of Multiband Superlattice Bloch Electrons in Quantum Kicked Potential

    Institute of Scientific and Technical Information of China (English)

    OUYANG BiYao; ZHAO XianGeng; CHEN ShiGang; LIU Jie

    2001-01-01

    In this paper, we study the dynamic behavior and quasi-energy spectrum of multiband superlattice Bloch electrons in quantum kicked potential. We show analytically and numerically the avoided crossing and band suppression about the quasi-energy spectrum, the dynamic nonlocalization, and the electron oscillation behavior between two bands.

  9. Budgeting for PACS.

    Science.gov (United States)

    Sim, Lh

    2008-10-01

    There are a number of models for the acquisition of digital image management systems. The specific details for development of a budget for a PACS/RIS acquisition will depend upon the acquisition model - although there are similarities in the overarching principles and general information, particularly concerning the radiology service requirements that will drive budget considerations.While budgeting for PACS/RIS should follow the same principles as budgeting for any new technology, it is important to understand how far the implementation of digital image management systems can reach in a healthcare setting. Accurate identification of those elements of the healthcare service that will be affected by a PACS/RIS implementation is a critical component of successful budget formation and of the success of any business case and subsequent project that relies on those budget estimates.A budget for a PACS/RIS capital acquisition project should contain capital and recurrent elements. The capital is associated with the acquisition of the system in a purchase model and capital budget may also be required for upgrade - depending upon a facility's financial management processes.The recurrent (or operational) cost component for the PACS/RIS is associated with maintaining the system(s) in a sustainable operational state.It is also important to consider the service efficiencies, cost savings and service quality improvements that PACS/RIS can generate and include these factors into the economic analysis of any proposal for a PACS/RIS project.

  10. Budgeting Based on Results

    Science.gov (United States)

    Cooper, Kelt L.

    2011-01-01

    Every program in a school or school district has, or once had, a purpose. The purpose was most likely promoted, argued and debated among school constituencies--parents, teachers, administrators and school board members--before it was eventually approved. This process occurs year after year, budget after budget. In itself, this is not necessarily a…

  11. Managing the Student Budget.

    Science.gov (United States)

    Faller, Martha Lewkus

    1984-01-01

    Looks at the factors complicating the management of student worker budgets in libraries (e.g., the number of separate but interrelated budgets involved). Proposes a budgetary system incorporating double-entry bookkeeping, continuous proving, and combination receipts and disbursements. Considers the advantages of the system and details procedures.…

  12. Learning From Low Budgets

    Institute of Scientific and Technical Information of China (English)

    2011-01-01

    Chinese filmmakers turn small-budget productions into box-office successes Organizers of China’s upcoming film festivals are finally giving recognition to the little guys—low budget films—to encourage a generation of young,talented directors.

  13. Effects of flooding-induced N2O production, consumption and emission dynamics on the annual N2O emission budget in wetland soil

    DEFF Research Database (Denmark)

    Jørgensen, Christian Juncher; Elberling, Bo

    2012-01-01

    during mid-summer when the WL was at its seasonally lowest counterbalancing ~6.4% of the total annual net N2O emission budget. Main surface emission periods of N2O were observed when the water level and associated peaks in subsurface N2O concentrations were gradually decreasing to soil depths down to 40...... production and consumption capacities where >500 nmol N2O cm-3 were sequentially produced and consumed in less than 24 hrs. It is concluded that a higher future frequency of flooding induced N2O emissions will have a very limited effect on the net annual N2O emission budget as long as NO3- availability...

  14. Relationship between dynamical entropy and energy dissipation far from thermodynamic equilibrium.

    Science.gov (United States)

    Green, Jason R; Costa, Anthony B; Grzybowski, Bartosz A; Szleifer, Igal

    2013-10-08

    Connections between microscopic dynamical observables and macroscopic nonequilibrium (NE) properties have been pursued in statistical physics since Boltzmann, Gibbs, and Maxwell. The simulations we describe here establish a relationship between the Kolmogorov-Sinai entropy and the energy dissipated as heat from a NE system to its environment. First, we show that the Kolmogorov-Sinai or dynamical entropy can be separated into system and bath components and that the entropy of the system characterizes the dynamics of energy dissipation. Second, we find that the average change in the system dynamical entropy is linearly related to the average change in the energy dissipated to the bath. The constant energy and time scales of the bath fix the dynamical relationship between these two quantities. These results provide a link between microscopic dynamical variables and the macroscopic energetics of NE processes.

  15. Farm-gate budget of energy crops: an experiment to assess changes in GHGs balance due to a land use change from grassland to short rotation coppice of poplar

    Science.gov (United States)

    Sabbatini, S.; Arriga, N.; Baiocco, A.; Boschi, A.; Castaldi, S.; Consalvo, C.; Gioli, B.; Matteucci, G.; Tomassucci, M.; Zaldei, A.; Papale, D.

    2012-04-01

    Over the last decades the rising in the prices of oil pushed many farmers all over the Europe to exploit part of their fields to produce biomass for energy. Government funding promoted this trend in order to contrast global warming and Green-House Gases (GHG) emissions. Nevertheless energy crops entail, in addition to a land use change, a sum of treatments that leads again to emissions of GHG. In the context of the GHG-Europe FP7 project we set-up an experiment to study a case of land use change from grassland to Short Rotation Coppice (SRC) of poplar clones in central Italy. Through the Eddy Covariance (EC) technique, we measure carbon and energy fluxes over two different poplar SRC with different ages, and over a reference site (grassland) representing the original land use. Furthermore, we measured additional fluxes such as soil respiration, CH4 and N2O fluxes using chambers. To compute the Farm-Gate Budget (FGB) of both the grassland and the poplar plantations, we collect also additional data that contribute to GHG budget such as management (tillage, fertilizations, irrigations, harvesting) and disturbances. In this poster we present the experiment set-up and the first results resulting from the measurements.

  16. Thermodynamic modeling, energy equipartition, and nonconservation of entropy for discrete-time dynamical systems

    Directory of Open Access Journals (Sweden)

    Chellaboina Vijaysekhar

    2005-01-01

    Full Text Available We develop thermodynamic models for discrete-time large-scale dynamical systems. Specifically, using compartmental dynamical system theory, we develop energy flow models possessing energy conservation, energy equipartition, temperature equipartition, and entropy nonconservation principles for discrete-time, large-scale dynamical systems. Furthermore, we introduce a new and dual notion to entropy; namely, ectropy, as a measure of the tendency of a dynamical system to do useful work and grow more organized, and show that conservation of energy in an isolated thermodynamic system necessarily leads to nonconservation of ectropy and entropy. In addition, using the system ectropy as a Lyapunov function candidate, we show that our discrete-time, large-scale thermodynamic energy flow model has convergent trajectories to Lyapunov stable equilibria determined by the system initial subsystem energies.

  17. Wind energy conversion. Volume IV. Drive system dynamics

    Energy Technology Data Exchange (ETDEWEB)

    Martinez-Sanchez, M.; Labuszewski, T.

    1978-09-01

    The dynamics of the drive system and various approaches to power transmission are described. The effects on performance of using a constant rotor speed as opposed to a rotor speed varying with the wind speed are discussed for various rotor operating schedules and typical wind distributions. The dynamics of the combined rotor, alternator, and drive system are analyzed. Conditions which could lead to electro-dynamic instabilities and desynchronization are discussed as well as means for stabilizing the system. The dynamics of the drive system and important design conditions for various drive systems are discussed, such as location of the alternators, use of hydraulic drive systems and smoothing techniques.

  18. Dynamic Spectrum Access in Cognitive Radio Networks with RF Energy Harvesting

    OpenAIRE

    Lu, Xiao; Wang,Ping; Dusit, Niyato; Ekram, Hossain

    2014-01-01

    Spectrum efficiency and energy efficiency are two critical issues in designing wireless networks. Through dynamic spectrum access, cognitive radios can improve the spectrum efficiency and capacity of wireless networks. On the other hand, radio frequency (RF) energy harvesting has emerged as a promising technique to supply energy to wireless networks and thereby increase their energy efficiency. Therefore, to achieve both spectrum and energy efficiencies, the secondary users in a cognitive rad...

  19. Realistic cosmological model with dynamical cancellation of vacuum energy

    CERN Document Server

    Dolgov, A D

    2003-01-01

    We propose a model with a compensating scalar field whose back reaction to the cosmological curvature cancels possible vacuum energy density down to the terms of the order of the time dependent critical energy density. Thus the model simultaneously solves the mystery of the compensation of vacuum energy with the accuracy of 120 orders of magnitude and explains existence of the observed dark energy. At an early stage the suggested cosmological model might experience exponential expansion without an additional inflaton field.

  20. Plug-in hybrid electric vehicles in dynamical energy markets

    NARCIS (Netherlands)

    Kessels, J.T.B.A.; Bosch, P.P.J. van den

    2008-01-01

    The plug-in hybrid electric vehicle allows vehicle propulsion from multiple internal power sources. Electric energy from the grid can be utilized by means of the plug-in connection. An on-line energy management (EM) strategy is proposed to minimize the costs for taking energy from each power source.

  1. Plug-in hybrid electric vehicles in dynamical energy markets

    NARCIS (Netherlands)

    Kessels, J.T.B.A.; Bosch, P.P.J. van den

    2008-01-01

    The plug-in hybrid electric vehicle allows vehicle propulsion from multiple internal power sources. Electric energy from the grid can be utilized by means of the plug-in connection. An on-line energy management (EM) strategy is proposed to minimize the costs for taking energy from each power source.

  2. Applying Fractal Dimensions and Energy-Budget Analysis to Characterize Fracturing Processes During Magma Migration and Eruption: 2011-2012 El Hierro (Canary Islands) Submarine Eruption

    Science.gov (United States)

    López, Carmen; Martí, Joan; Abella, Rafael; Tarraga, Marta

    2014-07-01

    The impossibility of observing magma migration inside the crust obliges us to rely on geophysical data and mathematical modelling to interpret precursors and to forecast volcanic eruptions. Of the geophysical signals that may be recorded before and during an eruption, deformation and seismicity are two of the most relevant as they are directly related to its dynamic. The final phase of the unrest episode that preceded the 2011-2012 eruption on El Hierro (Canary Islands) was characterized by local and accelerated deformation and seismic energy release indicating an increasing fracturing and a migration of the magma. Application of time varying fractal analysis to the seismic data and the characterization of the seismicity pattern and the strain and the stress rates allow us to identify different stages in the source mechanism and to infer the geometry of the path used by the magma and associated fluids to reach the Earth's surface. The results obtained illustrate the relevance of such studies to understanding volcanic unrest and the causes that govern the initiation of volcanic eruptions.

  3. Excitation-energy sorting in superfluid fission dynamics

    Directory of Open Access Journals (Sweden)

    Schmidt K.-H.

    2010-10-01

    Full Text Available It is now well established that at moderate excitation energies the nucleus temperature does not vary with increasing excitation energy. We show that, as a consequence, two nuclei with different temperatures brought into contact show a rather surprising energy-sorting mechanism where the hotter nucleus transfers all its excitation energy to the colder one. The scission configuration of the fission process offers a unique possibility to observe this phenomenon. The energy-sorting mechanism is clearly reflected by the mean number of prompt neutrons as a function of the fragment mass and by the dependence of the local even-odd effect with mass asymmetry.

  4. Dynamical aspects of intermediate-energy heavy-ion collisons

    Science.gov (United States)

    Dempsey, James Francis

    1997-10-01

    The production of neutrons, light charged particles (LCPs), and intermediate-mass fragments (IMFs), from the four reactions 55 MeV/A [124,136Xe] + [112,124Sn], is studied with an experimental apparatus which is highly efficient for the detection of both charged particles and neutrons. The IMFs are found more localized in the mid-velocity region (parallel velocity close to center of mass) than are the LPCs, and the detected multiplicity of IMFs depends linearly on the charge lost from the projectile. IMF multiplicity is found to be largely independent of the neutron excess of the system, aside from a slight increase with increasing neutron excess that is expected from statistical-model simulations. Remnants of the projectile, with very little velocity reduction, are found for most of the reaction cross section. Isotopic and isobaric fragment yields in the projectile-velocity region indicate that charge-to- mass ratio neutralization is generally not achieved but is approached when little remains of the projectile. For all systems, the fragments found in the mid-velocity region are substantially more neutron rich than those found in the velocity region dominated by the emission from the projectile. This observation can be qualitatively accounted for if the mid-velocity source (or sources) is either more neutron rich or smaller, with the same neutron-to-proton ratio, than the source with the velocity of the projectile. The observations of this work suggest that the intermediate mass fragments are, to a large extent, formed dynamically by a multiple neck rupture or a proximity-fission type mechanism. Though it remains unexplained, this process enhances the neutron- to-proton ratio of the emitted fragments. This scenario is reminiscent of low-energy ternary fission and one predicted by Boltzmann-Uehling-Uhlenbeck (BUU) calculations. However, these calculations predict too much velocity damping of the projectile remnant and do not produce a mid-velocity neutron

  5. Analysis of the US FY 2014 R & D budget on Energy and Climate Change%2014财年美国能源与气候变化研发预算解读

    Institute of Scientific and Technical Information of China (English)

    仲平; 禹庚

    2014-01-01

    The US federal government released its FY 2014 budget request in April, 2013. White House’s Ofifce of Science and Technology Policy (OSTP) then released the FY 2014 Federal R&D budget, and other R&D related federal agencies including Department of Energy (DOE) later released their respective agency budget details. Among the federal R&D request, budgets in the ifeld of energy and climate change increase remarkably, which relfects the determination of President Obama on developing clean energy economy, promoting US energy dependence and addressing the climate change. The R&D priorities in the area of energy and climate change include renewable energy, new-energy vehicle, clean coal, advanced manufacturing, green building and climate change. The paper also discussed the R&D trends in area of energy and climate change in the U.S.: setting mid-to long-term target of technology development to guide and mobilize resources to accelerate innovation;exploring the innovative funding and management model;establishing favorable market environment to foster the application and commercialization for new technologies including renewable energy technology.%2013年4月,奥巴马政府向美国国会正式提交了2014财年整体预算建议,白宫科技政策办公室(OSTP)、能源部(DOE)等联邦各部门随后也分别发布了2014财年联邦研发以及各自领域的预算明细。对研发预算的构成和分配的分析显示,美国在能源与气候变化领域研发预算增幅相对突出,体现了奥巴马在其第二任期内继续发展清洁能源产业、推动能源独立和应对气候变化的决心和努力。美国近期能源与气候变化的研发重点包括:可再生能源、新能源汽车、清洁煤技术、先进制造、建筑节能及气候变化等等。美国近年在能源和气候变化研发上的主要特点有:设定技术发展和应用的中长期目标,引导和调动各方面资源加速推动技术创新;不

  6. Pseudo Slice Energy Spread in Dynamics of Electron Beams Moving through Magnetic Bends

    CERN Document Server

    Li, Rui

    2014-01-01

    In the previous canonical formulation of beam dynamics for an electron bunch moving ultrarelativistically through magnetic bending systems, we have shown that the transverse dynamics equation for a particle in the bunch has a driving term which behaves as the centrifugal force caused by the particle's initial potential energy due to collective particle interactions within the bunch. As a result, the initial potential energy at the entrance of a bending system, which we call pseudo (kinetic) energy, is indistinguishable from the usual kinetic energy offset from the design energy in its perturbation to particle optics through dispersion and momentum compaction. In this paper, in identifying this centrifugal force on particles as the remnant of the CSR cancellation effect in transverse particle dynamics, we show how the dynamics equation in terms of the canonical momentum for beam motion on a curved orbit is related to the Panofsky-Wenzel theorem for wakefields for beam motion on a straight path. It is shown tha...

  7. Structural basis for catalytically restrictive dynamics of a high-energy enzyme state

    Science.gov (United States)

    Kovermann, Michael; Ådén, Jörgen; Grundström, Christin; Elisabeth Sauer-Eriksson, A.; Sauer, Uwe H.; Wolf-Watz, Magnus

    2015-07-01

    An emerging paradigm in enzymology is that transient high-energy structural states play crucial roles in enzymatic reaction cycles. Generally, these high-energy or `invisible' states cannot be studied directly at atomic resolution using existing structural and spectroscopic techniques owing to their low populations or short residence times. Here we report the direct NMR-based detection of the molecular topology and conformational dynamics of a catalytically indispensable high-energy state of an adenylate kinase variant. On the basis of matching energy barriers for conformational dynamics and catalytic turnover, it was found that the enzyme's catalytic activity is governed by its dynamic interconversion between the high-energy state and a ground state structure that was determined by X-ray crystallography. Our results show that it is possible to rationally tune enzymes' conformational dynamics and hence their catalytic power--a key aspect in rational design of enzymes catalysing novel reactions.

  8. Food restriction alters energy allocation strategy during growth in tobacco hornworms (Manduca sexta larvae).

    Science.gov (United States)

    Jiao, Lihong; Amunugama, Kaushalya; Hayes, Matthew B; Jennings, Michael; Domingo, Azriel; Hou, Chen

    2015-08-01

    Growing animals must alter their energy budget in the face of environmental changes and prioritize the energy allocation to metabolism for life-sustaining requirements and energy deposition in new biomass growth. We hypothesize that when food availability is low, larvae of holometabolic insects with a short development stage (relative to the low food availability period) prioritize biomass growth at the expense of metabolism. Driven by this hypothesis, we develop a simple theoretical model, based on conservation of energy and allometric scaling laws, for understanding the dynamic energy budget of growing larvae under food restriction. We test the hypothesis by manipulative experiments on fifth instar hornworms at three temperatures. At each temperature, food restriction increases the scaling power of growth rate but decreases that of metabolic rate, as predicted by the hypothesis. During the fifth instar, the energy budgets of larvae change dynamically. The free-feeding larvae slightly decrease the energy