WorldWideScience

Sample records for climate numerical analyses

  1. Numeric tools for tachogram analyse

    Directory of Open Access Journals (Sweden)

    Artur RYGUŁA

    2007-01-01

    Full Text Available Paper describes numeric application supporting driving analysis process on attitude of tachogram data. Actual accessible units recording road and speed in function of the time were used. Also potential optimisation areas of driving were shown. Additionally in the paper are presented road safety level in Poland in the context of dangerous driver’s behaviour.

  2. Numeric tools for tachogram analyse

    OpenAIRE

    Artur RYGUŁA; Andrzej MITAS

    2007-01-01

    Paper describes numeric application supporting driving analysis process on attitude of tachogram data. Actual accessible units recording road and speed in function of the time were used. Also potential optimisation areas of driving were shown. Additionally in the paper are presented road safety level in Poland in the context of dangerous driver’s behaviour.

  3. Impact of wind-driven rain on historic brick wall buildings in a moderately cold and humid climate: Numerical analyses of mould growth risk, indoor climate and energy consumption

    DEFF Research Database (Denmark)

    Masaru, Abuku; Janssen, Hans; Roels, Staf

    2009-01-01

    This paper gives an onset to whole building hygrothermal modelling in which the interaction between interior and exterior climates via building enclosures is simulated under a moderately cold and humid climate. The focus is particularly on the impact of wind-driven rain (WDR) oil the hygrothermal...... that WDR loads can have a significant impact on mould growth especially at the edges of the walls. Finally, for the case analysed, the WDR load Causes a significant increase of indoor relative humidity and energy consumption for heating. (C) 2008 Elsevier B.V. All rights reserved....

  4. A Climate System Model, Numerical Simulation and Climate Predictability

    Institute of Scientific and Technical Information of China (English)

    ZENG Qingcun; WANG Huijun; LIN Zhaohui; ZHOU Guangqing; YU Yongqiang

    2007-01-01

    @@ The implementation of the project has lasted for more than 20 years. As a result, the following key innovative achievements have been obtained, ranging from the basic theory of climate dynamics, numerical model development and its related computational theory to the dynamical climate prediction using the climate system models:

  5. Constructing a framework for risk analyses of climate change effects on the water budget of differently sloped vineyards with a numeric simulation using the Monte Carlo method coupled to a water balance model

    Directory of Open Access Journals (Sweden)

    Marco eHofmann

    2014-12-01

    Full Text Available Grapes for wine production are a highly climate sensitive crop and vineyard water budget is a decisive factor in quality formation. In order to conduct risk assessments for climate change effects in viticulture models are needed which can be applied to complete growing regions. We first modified an existing simplified geometric vineyard model of radiation interception and resulting water use to incorporate numerical Monte Carlo simulations and the physical aspects of radiation interactions between canopy and vineyard slope and azimuth. We then used four regional climate models to assess for possible effects on the water budget of selected vineyard sites up 2100. The model was developed to describe the partitioning of short-wave radiation between grapevine canopy and soil surface, respectively green cover, necessary to calculate vineyard evapotranspiration. Soil water storage was allocated to two sub reservoirs. The model was adopted for steep slope vineyards based on coordinate transformation and validated against measurements of grapevine sap flow and soil water content determined down to 1.6 m depth at three different sites over two years. The results showed good agreement of modelled and observed soil water dynamics of vineyards with large variations in site specific soil water holding capacity and viticultural management. Simulated sap flow was in overall good agreement with measured sap flow but site-specific responses of sap flow to potential evapotranspiration were observed. The analyses of climate change impacts on vineyard water budget demonstrated the importance of site-specific assessment due to natural variations in soil water holding capacity. The improved model was capable of describing seasonal and site-specific dynamics in soil water content and could be used in an amended version to estimate changes in the water budget of entire grape growing areas due to evolving climatic changes.

  6. Constructing a framework for risk analyses of climate change effects on the water budget of differently sloped vineyards with a numeric simulation using the Monte Carlo method coupled to a water balance model.

    Science.gov (United States)

    Hofmann, Marco; Lux, Robert; Schultz, Hans R

    2014-01-01

    Grapes for wine production are a highly climate sensitive crop and vineyard water budget is a decisive factor in quality formation. In order to conduct risk assessments for climate change effects in viticulture models are needed which can be applied to complete growing regions. We first modified an existing simplified geometric vineyard model of radiation interception and resulting water use to incorporate numerical Monte Carlo simulations and the physical aspects of radiation interactions between canopy and vineyard slope and azimuth. We then used four regional climate models to assess for possible effects on the water budget of selected vineyard sites up 2100. The model was developed to describe the partitioning of short-wave radiation between grapevine canopy and soil surface, respectively, green cover, necessary to calculate vineyard evapotranspiration. Soil water storage was allocated to two sub reservoirs. The model was adopted for steep slope vineyards based on coordinate transformation and validated against measurements of grapevine sap flow and soil water content determined down to 1.6 m depth at three different sites over 2 years. The results showed good agreement of modeled and observed soil water dynamics of vineyards with large variations in site specific soil water holding capacity (SWC) and viticultural management. Simulated sap flow was in overall good agreement with measured sap flow but site-specific responses of sap flow to potential evapotranspiration were observed. The analyses of climate change impacts on vineyard water budget demonstrated the importance of site-specific assessment due to natural variations in SWC. The improved model was capable of describing seasonal and site-specific dynamics in soil water content and could be used in an amended version to estimate changes in the water budget of entire grape growing areas due to evolving climatic changes. PMID:25540646

  7. Climate system model, numerical simulation and climate predictability

    Institute of Scientific and Technical Information of China (English)

    2010-01-01

    @@ Thanks to its work of past more than 20 years,a research team led by Prof.ZENG Qingcun and Prof.WANG Huijun from the CAS Institute of Atmospheric Physics (IAP) has scored innovative achievements in their studies of basic theory of climate dynamics,numerical model development,its related computational theory,and the dynamical climate prediction using the climate system models.Their work received a second prize of the National Award for Natural Sciences in 2005.

  8. Use of EBSD Data in Numerical Analyses

    Energy Technology Data Exchange (ETDEWEB)

    Becker, R; Wiland, H

    2000-01-14

    Experimentation, theory and modeling have all played vital roles in defining what is known about microstructural evolution and the effects of microstructure on material properties. Recently, technology has become an enabling factor, allowing significant advances to be made on several fronts. Experimental evidence of crystallographic slip and the basic theory of crystal plasticity were established in the early 20th Century, and the theory and models evolved incrementally over the next 60 years. (Asaro provides a comprehensive review of the mechanisms and basic plasticity models.) During this time modeling was primarily concerned with the average response of polycrystalline aggregates. While some detailed finite element modeling (FEM) with crystal plasticity constitutive relations was done in the early 1980s, such simulations over taxed the capabilities of the available computer hardware. Advances in computer capability led to a flurry of activity in finite element modeling in the next 10 years, increasing understanding of microstructure evolution and pushing the limits of theories and material characterization. Automated Electron Back Scatter Diffraction (EBSD) has produced a similar revolution in material characterization. The data collected is extensive and many questions about the evolution of microstructure and its role in determining mechanic properties can now be addressed. It is also now possible to obtain sufficient information about lattice orientations on a fine enough scale to allow detailed quantitative comparisons of experiments and newly emerging large scale numerical simulations. The insight gained from the coupling of EBSD and FEM studies will provide impetus for further development of microstructure models and theories of microstructure evolution. Early studies connecting EBSD data to finite element models used manual measurements to define initial orientations for the simulation. In one study, manual measurements of the deformed structure were also

  9. Advancement and prospect of short-term numerical climate prediction

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    The defects of present methods of short-term numerical climate prediction are discussed in this paper, and four challenging problems are put forward. Considering our under developed computer conditions, we should innovate in the approcuch of numerical climate prediction on the basis of our own achievements and experiences in the field of short-term numerical climate prediction. It is possibly an effective way to settle the present defects of short-term numerical climate prediction.``

  10. The FORBIO Climate data set for climate analyses

    OpenAIRE

    Delvaux, C.; M. Journée; Bertrand, C.

    2015-01-01

    In the framework of the interdisciplinary FORBIO Climate research project, the Royal Meteorological Institute of Belgium is in charge of providing high resolution gridded past climate data (i.e. temperature and precipitation). This climate data set will be linked to the measurements on seedlings, saplings and mature trees to assess the effects of climate variation on tree performance. This paper explains how the gridded daily temperature (minimum and maximum) data set was ge...

  11. Seafloor weathering buffering climate: numerical experiments

    Science.gov (United States)

    Farahat, N. X.; Archer, D. E.; Abbot, D. S.

    2013-12-01

    Continental silicate weathering is widely held to consume atmospheric CO2 at a rate controlled in part by temperature, resulting in a climate-weathering feedback [Walker et al., 1981]. It has been suggested that weathering of oceanic crust of warm mid-ocean ridge flanks also has a CO2 uptake rate that is controlled by climate [Sleep and Zahnle, 2001; Brady and Gislason, 1997]. Although this effect might not be significant on present-day Earth [Caldeira, 1995], seafloor weathering may be more pronounced during snowball states [Le Hir et al., 2008], during the Archean when seafloor spreading rates were faster [Sleep and Zahnle, 2001], and on waterworld planets [Abbot et al., 2012]. Previous studies of seafloor weathering have made significant contributions using qualitative, generally one-box, models, and the logical next step is to extend this work using a spatially resolved model. For example, experiments demonstrate that seafloor weathering reactions are temperature dependent, but it is not clear whether the deep ocean temperature affects the temperature at which the reactions occur, or if instead this temperature is set only by geothermal processes. Our goal is to develop a 2-D numerical model that can simulate hydrothermal circulation and resulting alteration of oceanic basalts, and can therefore address such questions. A model of diffusive and convective heat transfer in fluid-saturated porous media simulates hydrothermal circulation through porous oceanic basalt. Unsteady natural convection is solved for using a Darcy model of porous media flow that has been extensively benchmarked. Background hydrothermal circulation is coupled to mineral reaction kinetics of basaltic alteration and hydrothermal mineral precipitation. In order to quantify seafloor weathering as a climate-weathering feedback process, this model focuses on hydrothermal reactions that influence carbon uptake as well as ocean alkalinity: silicate rock dissolution, calcium and magnesium leaching

  12. Scenario evolution: Interaction between event tree construction and numerical analyses

    International Nuclear Information System (INIS)

    Construction of well-posed scenarios for the range of conditions possible at any proposed repository site is a critical first step to assessing total system performance. Even tree construction is the method that is being used to develop potential failure scenarios for the proposed nuclear waste repository at Yucca Mountain. An event tree begins with an initial event or condition. Subsequent events are listed in a sequence, leading eventually to release of radionuclides to the accessible environment. Ensuring the validity of the scenarios requires iteration between problems constructed using scenarios contained in the event tree sequence, experimental results, and numerical analyses. Details not adequately captured within the tree initially may become more apparent as a result of analyses. To illustrate this process, we discuss the iterations used to develop numerical analyses for PACE-90 using basaltic igneous activity and human-intrusion event trees

  13. Scenario evolution: Interaction between event tree construction and numerical analyses

    International Nuclear Information System (INIS)

    Construction of well-posed scenarios for the range of conditions possible at any proposed repository site is a critical first step to assessing total system performance. Event tree construction is the method that is being used to develop potential failure scenarios for the proposed nuclear waste repository at Yucca Mountain. An event tree begins with an initial event or condition. Subsequent events are listed in a sequence, leading eventually to release of radionuclides to the accessible environment. Ensuring the validity of the scenarios requires iteration between problems constructed using scenarios contained in the event tree sequence, experimental results, and numerical analyses. Details not adequately captured within the tree initially may become more apparent as a result of analyses. To illustrate this process, the authors discuss the iterations used to develop numerical analyses for PACE-90 (Performance Assessment Calculational Exercises) using basaltic igneous activity and human-intrusion event trees

  14. The FORBIO Climate data set for climate analyses

    Science.gov (United States)

    Delvaux, C.; Journée, M.; Bertrand, C.

    2015-06-01

    In the framework of the interdisciplinary FORBIO Climate research project, the Royal Meteorological Institute of Belgium is in charge of providing high resolution gridded past climate data (i.e. temperature and precipitation). This climate data set will be linked to the measurements on seedlings, saplings and mature trees to assess the effects of climate variation on tree performance. This paper explains how the gridded daily temperature (minimum and maximum) data set was generated from a consistent station network between 1980 and 2013. After station selection, data quality control procedures were developed and applied to the station records to ensure that only valid measurements will be involved in the gridding process. Thereafter, the set of unevenly distributed validated temperature data was interpolated on a 4 km × 4 km regular grid over Belgium. The performance of different interpolation methods has been assessed. The method of kriging with external drift using correlation between temperature and altitude gave the most relevant results.

  15. Climate protection: The importance of cost-benefit analyses

    International Nuclear Information System (INIS)

    Cost-benefit analyses are an important decision tool in global environmental and energy policy. But are they also useful within the framework of global climate protection policy? The Wuppertal Institute, the Potsdam Institute and the federal ministry of science and technology held a workshop on this subject. This event was the first to bring together leading representatives of climate model research, climate research and climate policy in a joint discussion on the ''economy of climate protection''. This 'Wuppertal Text' contains the revised and updated contributions to the workshop (orig.)

  16. Dynamic behaviour of a rolling tyre: Experimental and numerical analyses

    Science.gov (United States)

    Gonzalez Diaz, Cristobal; Kindt, Peter; Middelberg, Jason; Vercammen, Stijn; Thiry, Christophe; Close, Roland; Leyssens, Jan

    2016-03-01

    Based on the results of experimental and numerical analyses, the effect of rotation on the tyre dynamic behaviour is investigated. Better understanding of these effects will further improve the ability to control and optimize the noise and vibrations that result from the interaction between the road surface and the rolling tyre. Therefore, more understanding in the complex tyre dynamic properties will contribute to develop tyre design strategies to lower the tyre/road noise while less affecting other tyre performances. The presented work is performed in the framework of the European industry-academia project TIRE-DYN, with partners Goodyear, Katholieke Universiteit Leuven and LMS International. The effect of rotation on the tyre dynamic behaviour is quantified for different operating conditions of the tyre, such as load, air pressure and rotation speed. By means of experimental and numerical analyses, the effects of rotation on the tyre dynamic behaviour are studied.

  17. Analysing climate impact on energy demand using the MOLAND model

    OpenAIRE

    Liu, Xiaochen; Twumasi, Bright Osei

    2008-01-01

    The importance and contribution of climate to energy demand are discussed. A linear regression model is developed to analyse future energy demand corresponding to climate change. The methodology for spatial analysis and integration to MOLAND are also provided in order to investigate possible consequences of different urban development paths on energy consumption patterns.

  18. NUMERICAL ANALYSES OF THE UNDERGROUND EXPLOITATION OF DIMENSION STONE

    Directory of Open Access Journals (Sweden)

    Biljana Kovačević-Zelić

    1996-12-01

    Full Text Available Underground exploitation of dimension stone is spreading lately for three main reasons; economy, organisation and environment. Moreover, underground openings can be used for many purposes. Underground exploitation is different from surface quarrying only in the first stage, the removal of top slice, descending slices are worked as in conventional quarries. In underground stone quarries, stability problems require adequate studies in order to avoid expensive artificial support measures, The article presents numerical analyses of an underground stone quarry made using of the finite difference code FLAC (the paper is published in Croatian.

  19. Regional Scale Analyses of Climate Change Impacts on Agriculture

    Science.gov (United States)

    Wolfe, D. W.; Hayhoe, K.

    2006-12-01

    New statistically downscaled climate modeling techniques provide an opportunity for improved regional analysis of climate change impacts on agriculture. Climate modeling outputs can often simultaneously meet the needs of those studying impacts on natural as well as managed ecosystems. Climate outputs can be used to drive existing forest or crop models, or livestock models (e.g., temperature-humidity index model predicting dairy milk production) for improved information on regional impact. High spatial resolution climate forecasts, combined with knowledge of seasonal temperatures or rainfall constraining species ranges, can be used to predict shifts in suitable habitat for invasive weeds, insects, and pathogens, as well as cash crops. Examples of climate thresholds affecting species range and species composition include: minimum winter temperature, duration of winter chilling (vernalization) hours (e.g., hours below 7.2 C), frost-free period, and frequency of high temperature stress days in summer. High resolution climate outputs can also be used to drive existing integrated pest management models predicting crop insect and disease pressure. Collectively, these analyses can be used to test hypotheses or provide insight into the impact of future climate change scenarios on species range shifts and threat from invasives, shifts in crop production zones, and timing and regional variation in economic impacts.

  20. NASA Earth Exchange (NEX) Supporting Analyses for National Climate Assessments

    Science.gov (United States)

    Nemani, R. R.; Thrasher, B. L.; Wang, W.; Lee, T. J.; Melton, F. S.; Dungan, J. L.; Michaelis, A.

    2015-12-01

    The NASA Earth Exchange (NEX) is a collaborative computing platform that has been developed with the objective of bringing scientists together with the software tools, massive global datasets, and supercomputing resources necessary to accelerate research in Earth systems science and global change. NEX supports several research projects that are closely related with the National Climate Assessment including the generation of high-resolution climate projections, identification of trends and extremes in climate variables and the evaluation of their impacts on regional carbon/water cycles and biodiversity, the development of land-use management and adaptation strategies for climate-change scenarios, and even the exploration of climate mitigation through geo-engineering. Scientists also use the large collection of satellite data on NEX to conduct research on quantifying spatial and temporal changes in land surface processes in response to climate and land-cover-land-use changes. Researchers, leveraging NEX's massive compute/storage resources, have used statistical techniques to downscale the coarse-resolution CMIP5 projections to fulfill the demands of the community for a wide range of climate change impact analyses. The DCP-30 (Downscaled Climate Projections at 30 arcsecond) for the conterminous US at monthly, ~1km resolution and the GDDP (Global Daily Downscaled Projections) for the entire world at daily, 25km resolution are now widely used in climate research and applications, as well as for communicating climate change. In order to serve a broader community, the NEX team in collaboration with Amazon, Inc, created the OpenNEX platform. OpenNEX provides ready access to NEX data holdings, including the NEX-DCP30 and GDDP datasets along with a number of pertinent analysis tools and workflows on the AWS infrastructure in the form of publicly available, self contained, fully functional Amazon Machine Images (AMI's) for anyone interested in global climate change.

  1. Improving Climate Communication through Comprehensive Linguistic Analyses Using Computational Tools

    Science.gov (United States)

    Gann, T. M.; Matlock, T.

    2014-12-01

    An important lesson on climate communication research is that there is no single way to reach out and inform the public. Different groups conceptualize climate issues in different ways and different groups have different values and assumptions. This variability makes it extremely difficult to effectively and objectively communicate climate information. One of the main challenges is the following: How do we acquire a better understanding of how values and assumptions vary across groups, including political groups? A necessary starting point is to pay close attention to the linguistic content of messages used across current popular media sources. Careful analyses of that information—including how it is realized in language for conservative and progressive media—may ultimately help climate scientists, government agency officials, journalists and others develop more effective messages. Past research has looked at partisan media coverage of climate change, but little attention has been given to the fine-grained linguistic content of such media. And when researchers have done detailed linguistic analyses, they have relied primarily on hand-coding, an approach that is costly, labor intensive, and time-consuming. Our project, building on recent work on partisan news media (Gann & Matlock, 2014; under review) uses high dimensional semantic analyses and other methods of automated classification techniques from the field of natural language processing to quantify how climate issues are characterized in media sources that differ according to political orientation. In addition to discussing varied linguistic patterns, we share new methods for improving climate communication for varied stakeholders, and for developing better assessments of their effectiveness.

  2. Mathematical and Numerical Analyses of Peridynamics for Multiscale Materials Modeling

    Energy Technology Data Exchange (ETDEWEB)

    Du, Qiang [Pennsylvania State Univ., State College, PA (United States)

    2014-11-12

    The rational design of materials, the development of accurate and efficient material simulation algorithms, and the determination of the response of materials to environments and loads occurring in practice all require an understanding of mechanics at disparate spatial and temporal scales. The project addresses mathematical and numerical analyses for material problems for which relevant scales range from those usually treated by molecular dynamics all the way up to those most often treated by classical elasticity. The prevalent approach towards developing a multiscale material model couples two or more well known models, e.g., molecular dynamics and classical elasticity, each of which is useful at a different scale, creating a multiscale multi-model. However, the challenges behind such a coupling are formidable and largely arise because the atomistic and continuum models employ nonlocal and local models of force, respectively. The project focuses on a multiscale analysis of the peridynamics materials model. Peridynamics can be used as a transition between molecular dynamics and classical elasticity so that the difficulties encountered when directly coupling those two models are mitigated. In addition, in some situations, peridynamics can be used all by itself as a material model that accurately and efficiently captures the behavior of materials over a wide range of spatial and temporal scales. Peridynamics is well suited to these purposes because it employs a nonlocal model of force, analogous to that of molecular dynamics; furthermore, at sufficiently large length scales and assuming smooth deformation, peridynamics can be approximated by classical elasticity. The project will extend the emerging mathematical and numerical analysis of peridynamics. One goal is to develop a peridynamics-enabled multiscale multi-model that potentially provides a new and more extensive mathematical basis for coupling classical elasticity and molecular dynamics, thus enabling next

  3. Using Weather Data and Climate Model Output in Economic Analyses of Climate Change

    Energy Technology Data Exchange (ETDEWEB)

    Auffhammer, Maximilian [University of California at Berkeley; Hsiang, Solomon M. [Princeton University; Schlenker, Wolfram [Columbia University; Sobel, Adam H. [Columbia University

    2013-06-28

    Economists are increasingly using weather data and climate model output in analyses of the economic impacts of climate change. This article introduces a set of weather data sets and climate models that are frequently used, discusses the most common mistakes economists make in using these products, and identifies ways to avoid these pitfalls. We first provide an introduction to weather data, including a summary of the types of datasets available, and then discuss five common pitfalls that empirical researchers should be aware of when using historical weather data as explanatory variables in econometric applications. We then provide a brief overview of climate models and discuss two common and significant errors often made by economists when climate model output is used to simulate the future impacts of climate change on an economic outcome of interest.

  4. Numerical FEM Analyses of primary coolant system at NPP Temelin

    International Nuclear Information System (INIS)

    The main goal of this paper is to inform about the beginning and first steps of implementation of an aging management system at the Temelin NPP. The aging management system is important not only for achieving the current safety level but also for reaching operational reliability of a production unit equipment above the life time assumed by the original design, typically over 40 years. A method to locate the most prominent degradation regions is described. A global shell model of the primary coolant system including all loops and their components - reactor pressure vessel (RPV), steam generator (SG), main coolant pump (MCP), pressurizer, feed water and steam pipelines system is presented. The results of stress-strain analysis on the measured service parameters base are given. Validation of the results is very important and the method to compare the service measurement data with the numerical results is described. The global/local approach is mentioned and discussed. The effects of the complete global system on the individual components under monitoring are transformed into more accurate local spatial models. The local spatial models are used to analyze the gradual lifetime exhaustion of a facility during its service operation. Two spatial local models are presented, viz. feed water nozzle of SG and main coolant piping system T-brunch. The results of analysis of the local spatial models are processed by the neural network computing method, which is also described. The actual gradual damage of the material of the components under monitoring can be obtained based on the analyses performed and on the results from the neural network in combination with the knowledge of the real material characteristics. The procedures applied are included in the DIALIFE diagnostic system

  5. Seasonal cycle of Martian climate : Experimental data and numerical simulation

    NARCIS (Netherlands)

    Rodin, A. V.; Willson, R. J.

    2006-01-01

    The most adequate theoretical method of investigating the present-day Martian climate is numerical simulation based on a model of general circulation of the atmosphere. First and foremost, such models encounter the greatest difficulties in description of aerosols and clouds, which in turn essentiall

  6. ANALYSES OF LANDSCAPE GEOGRAPHIC IMPACTS OF POTENTIAL CLIMATE CHANGE IN HUNGARY

    Directory of Open Access Journals (Sweden)

    PÉTER CSORBA

    2012-06-01

    Full Text Available Change of climate can be a remarkable turning point in the 21st century history of mankind. An important task of landscape geographic research is forecasting environmental, nature protection, land use demands and helping mitigation of disadvantageous processes from the aspect of society. ALADIN and REMO numeric climate models predict strong warming and lack of summer precipitation for the area of Hungary for the period between 2021 and 2100. There is a predictedgrowth in frequency of extreme weather events (heat waves, droughts hailstorms. Changes have been forecasted using data presented in table 1. For analyses of complex landscape geographic impacts ofclimate change the area of Hungary have been divided into 18 mesoregions with 5.000-10.000 km2 area each (figure 1. The main aspect of choosing the regions was that they should have homogeneousphysical, geographic and land use endowments and, for this reason, they should react to climate change the same way. Relationships between landscape forming factors and meteorological elementsexamined by us have been taken into consideration. Results of analyses of impacts of the meteorological factors on the changes of relief through the mass movements are presented in this paper. Changes of landscape sensibility of mesoregions to mass movements have been presented in the last chapter for the periods between 2021-2050 and 2071-2100 according to numeric climate models.

  7. Numerical tables on physical and chemical analyses of Rhine water

    International Nuclear Information System (INIS)

    Tables on the places of measurement, the sampling methods and the methods of analysis used. The numerical tables of the measurement results are broken down in general parameters, organic, entrophicating and anorganic substances, orgnic micro-pollutants and radioactivity. (GG)

  8. Mathematical and Numerical Analyses of Peridynamics for Multiscale Materials Modeling

    Energy Technology Data Exchange (ETDEWEB)

    Gunzburger, Max [Florida State Univ., Tallahassee, FL (United States)

    2015-02-17

    We have treated the modeling, analysis, numerical analysis, and algorithmic development for nonlocal models of diffusion and mechanics. Variational formulations were developed and finite element methods were developed based on those formulations for both steady state and time dependent problems. Obstacle problems and optimization problems for the nonlocal models were also treated and connections made with fractional derivative models.

  9. Analytical and numerical analyses of hydrologic well-bore experiments

    International Nuclear Information System (INIS)

    An analytical approximate method and a finite-difference numerical model (based on the rate at which a borehole fills with water) were developed to estimate permeability of the Magenta Formation in southeastern New Mexico near the proposed Waste Isolation Pilot Project (WIPP) site. The analytical treatment applies to certain simple geometries with idealized boundary conditions (constant properties, ground water compressibility negligible). Permissible geometries include water-collecting cylinders with large needle-like aspect ratios located beneath the water table. The analytical treatment clearly shows the sensitivity of inferences and conclusions to material properties and geometries. Much of the existing well-bore fill-rate data fall within the range of validity of this simplified analysis. Admission of compressibility effects into the generalized Darcy law, and a nondimensionalization of the equations identify the range of experimental conditions and material properties for which the approximations are invalid. In the numerical capability to complement this analytical treatment, numerous restrictions have been removed so that the code can treat complex geometries for a variety of boundary conditions and variable properties. The compressibility term that is excluded in the analytical treatment is maintained in these numerical solutions. The resulting equations are formally parabolicand can be solved by an implicit integrator with guaranteed stability. The two methods, applied to several different experimental situations, agree with each other. 9 figures, 3 tables

  10. Application of climatic indices to analyse viticultural suitability in Extremadura, south-western Spain

    Science.gov (United States)

    Moral, Francisco J.; Rebollo, Francisco J.; Paniagua, Luis L.; García, Abelardo; de Salazar, Enrique Martínez

    2016-01-01

    Although climate is recognised as one of the main drivers of viticulture success, its main features have not been sufficiently described in many viticultural regions, including Extremadura, which contains one of the largest grapevine-growing areas in Europe. Using climatic data from 80 weather stations located throughout Extremadura, seven bioclimatic indices were calculated to estimate heat accumulation and potential water balance during the growing season and the thermal regime during the ripening of grapes. Differences in some climatic indices were found, and after a multivariate geographic analysis, four groups were delimited containing weather stations with similar climatic features, with variability between groups explained by heat accumulation and tempearture and thermal amplitude during the ripening season. Suitability for cultivation of grapevines without thermal restriction and temperate nights during the ripening period are the main characteristics of the weather stations studied, but spatial variability found in climatic potential denotes the importance of differentiating locations to properly relate the viticultural climate to grape quality factors and the style of wines produced. The climatic features of the four groups are very similar to those described in other viticultural regions, including those in close proximity to Extremadura and others worldwide, but few studies have used broad and updated temporal climate data for computing bioclimatic indices as in this case study. Finally, trends in climate indices were analysed. Results revealed that all groups have experienced warmer growing seasons, driven mainly by changes in minimum temperatures. This fact has numerous potential impacts, including changes in grapevine phenological timing, disruption of balanced composition in grapes (ultimately affecting wine characteristics), alterations in varieties grown and spatial changes in viable winegrape-growing zones.

  11. Numerical and Experimental Analyses of Residual Stresses in

    DEFF Research Database (Denmark)

    Hansen, Jan Langkjær; Hattel, Jesper; Lorentzen, Torben

    1999-01-01

    Butt-welding in one pass with SMAW of two 10mm mild steel plates is investigated. In order to predict the residual stress fields associated with the welding procedure, a finite element model in 3D has been developed in ABAQUS. This model applies a sequential thermal and mechanical numerical...... analysis. In order to evaluate and refine the model parameters for the thermal analysis, the numerical results from this analysis are compared with experimental measurements of the temperature. To evaluate the predicted stress/strain fields, the mechanical model has been validated experimentally. This has...... been done using the novel non-destructive technique of neutron diffraction.The thermal model takes into account the moving heat source in the V-shaped weld. The heat source is modelled by filler material being added continuously in connection with a body flux. In order to obtain a more realistic weld...

  12. Experimental and numerical analyses of micro rotary shaft pumps

    International Nuclear Information System (INIS)

    This paper presents experimental and numerical results obtained with micro rotary shaft pumps (RSP). Impellers with a diameter of 2.5 mm, different outlet widths and blade number were coupled with semicircular volutes with different eccentricities. Experimental data for every impeller–volute couple were reported and include the flow rate, head and overall efficiency. Different rotational speeds were tested up to 24 000 rpm, obtaining pressure increases up to 5.7 kPa and flow rates up to 80 ml min−1. The non-dimensional performance was also computed obtaining the maximum head coefficient of 0.49 and the maximum flow coefficient of 0.138. Furthermore, experimental data were compared with 3D time-dependent CFD simulations. The focus of the simulation was to study the flow field structure inside the impeller and in the volute. Moreover, CFD data allowed for the calculation of the hydraulic efficiency of the pump and for the impeller to highlight the stator rotor interference influence on the pump characteristics, as well as to show the distribution of losses inside the volute

  13. Analysis on the Characteristics of Fluvial Evolution with Climate Changes from Numerical Simulation

    Science.gov (United States)

    Yan, Zhenzhen

    2014-05-01

    Landform evolution is one part of the Earth system behaviors. Products from the landform evolution are faithful records for the global change. They are created by complex interaction between geomorphic processes and environmental factors, and be able to provide the most important and intuitive evidences for investigating the interaction between the Earth's tectonic processes and climate changes. Because of very limited geodetic and geological data, we need a profound understanding of how landscapes respond and erode in response to changes in tectonic or climate boundary conditions. Quantitative study on landform evolution in different spatial and temporal scales using numerical simulation has important scientific interest and practical significance for investigating the nonlinear coupling relationship and response mechanism between tectonic activity, climate change, and surface processes. Under background of the global climate change, rivers have been a major focus of research in landform evolution because they are patently sensitive to tectonic and climate forcing via their channel characteristics. According to the existing research on the channel profiles, in this study, we employ numerical method incorporated with remote sensing techniques to investigate the surface process response to climate-tectonic-landscape through analysis and verification exploration. We build a numerical model based on the theory of geomorphic evolution, and take study on dynamical processes of the channel profile evolution with tectonic and climate boundary. Primary simulation results show that the linear diffusion is not enough to demonstrate the whole evolution. The analyses show that erosion plays a major role in fluvial evolution. Analysis on the dynamic processes of fluvial evolution, clarification its morphological characteristics, and exploration its formation and evolution is helpful for thorough study and understanding the relationship between the various factors of fluvial

  14. Analyses on Climate Characteristics in Xingtai City during 1954 - 2010

    Institute of Scientific and Technical Information of China (English)

    2011-01-01

    [Objective]The research aimed to analyze climate characteristics in Xingtai City during 1954-2010.[Method] Based on climate data in Xingtai City during 1954-2010,by using line chart,trend chart,climatic variability and statistical diagram,the climate characteristics in Xingtai City in 57 years were analyzed.[Result] The annual average temperature,annual average maximum and minimum temperatures in Xingtai City during 1954-2010 all presented gradual rise trend.The rise velocity of annual average maximum tempe...

  15. Comparison of Numerical Analyses with a Static Load Test of a Continuous Flight Auger Pile

    Directory of Open Access Journals (Sweden)

    Hoľko Michal

    2014-12-01

    Full Text Available The article deals with numerical analyses of a Continuous Flight Auger (CFA pile. The analyses include a comparison of calculated and measured load-settlement curves as well as a comparison of the load distribution over a pile's length. The numerical analyses were executed using two types of software, i.e., Ansys and Plaxis, which are based on FEM calculations. Both types of software are different from each other in the way they create numerical models, model the interface between the pile and soil, and use constitutive material models. The analyses have been prepared in the form of a parametric study, where the method of modelling the interface and the material models of the soil are compared and analysed.

  16. Climate analyses in Emad-deh, Larestan, Fars Province, Iran

    Science.gov (United States)

    Bahrami, M.

    2009-04-01

    Different meteorological parameters like precipitation, temperature, sunny hours, relative humidity, wind, number of freezing days, evaporation and transpiration are used to analyze and evaluate the climate of a region for presenting various development and agricultural projects. The aim of this paper is to study these parameters in order to present flood control and artificial recharge project in the Emad-deh Watershed Basin. The quantitative and qualitative determination of existing data has important role in data analyses. There are different methods for being assure of data homogeneity, and in this paper run test has been used. Since there is no any meteorological in the Emad-deh Watershed Basin, the data of surrounding stations have been used. Amongst these stations, the Larestan Station, with 46 years of precipitation data, and lesser time for other meteorological parameters, regarding to its long period of data collection, proximity to the study basin and suitable attention in data recording has been chosen as base station. According to the existing data from 1960 to 2006 (46 years), the maximum, the average and the minimum amount of precipitation in Larestan Station have been 746.5, 247.6 and 40.5 mm, respectively. These parameters for Emad-deh Basin were 663.3, 220 and 36 mm, respectively. The temperature indicators consisting absolute maximum, maximum average, daily average, minimum average and absolute minimum that in Larestan Station with a duration of 37 years from 1964 to 2001 have been reported annually 74˚c, 31.5˚c, 23.9˚c, 16.1˚c and -3˚c , respectively. These indicators for Emad-deh Basin have been calculated 44.1˚c, 28.3˚c, 21.5˚c, 14.5˚c and -3.3˚c , respectively. Daily sunny hours in each month from 1992 to 2003 showed in Larestan Station, in that the minimum was 7.5 hours in February and the maximum was 11.4 hours in June. The monthly maximum average of the relative humidity was reported 62.4% in January and the annual average 44

  17. An abrupt stochastic damage function to analyse climate policy benefits

    OpenAIRE

    Ha-Duong, Minh; Dumas, Patrice

    2004-01-01

    Chapter in Alain Haurie and Laurent Viguier (eds.) 2005, The coupling of climate and economic dynamics, Essays on Integrated Assessment. Series: Advances in Global Change Research, Vol. 22 , Kluwerhttp://www.centre-cired.fr/perso/haduong/files/Dumas.ea-2004-AbruptStochasticDamage.pdf This paper studies uncertainty about the non-linearity of climate change impact. The DIAM 2.3 model is used to compute the sensitivity of optimal CO2 emissions paths with respect to damage function parameters....

  18. Bearing Capacity of Spatially Random Cohesive Soil Using Numerical Limit Analyses

    OpenAIRE

    Kasama, Kiyonobu; Whittle, Andrew

    2007-01-01

    This paper describes a probabilistic study of the two dimensional bearing capacity of a vertically loaded strip footing on spatially random, cohesive soil using Numerical Limit Analyses (NLA‐CD). The analyses uses a Cholesky Decomposition (CD) technique with mid‐point discretization to represent the spatial variation in undrained shear strength within finite element meshes for both upper and lower bound analyses, and assumes an isotropic correlation length. Monte Carlo simulations are then us...

  19. How scaling fluctuation analyses can transform our view of the climate

    Science.gov (United States)

    Lovejoy, Shaun; Schertzer, Daniel

    2013-04-01

    There exist a bewildering diversity of proxy climate data including tree rings, ice cores, lake varves, boreholes, ice cores, pollen, foraminifera, corals and speleothems. Their quantitative use raises numerous questions of interpretation and calibration. Even in classical cases - such as the isotope signal in ice cores - the usual assumption of linear dependence on ambient temperature is only a first approximation. In other cases - such as speleothems - the isotope signals arise from multiple causes (which are not always understood) and this hinders their widespread use. We argue that traditional interpretations and calibrations - based on essentially deterministic comparisons between instrumental data, model outputs and proxies (albeit with the help of uncertainty analyses) - have been both overly ambitious while simultaneously underexploiting the data. The former since comparisons typically involve series at different temporal resolutions and from different geographical locations - one does not expect agreement in a deterministic sense, while with respect to climate models, one only expects statistical correspondences. The proxies are underexploited since comparisons are done at unique temporal and / or spatial resolutions whereas the fluctuations they describe provide information over wide ranges of scale. A convenient method of overcoming these difficulties is the use of fluctuation analysis systematically applied over the full range of available scales to determine the scaling proeprties. The new transformative element presented here, is to define fluctuations ΔT in a series T(t) at scale Δt not by differences (ΔT(Δt) = T(t+Δt) - T(t)) but rather by the difference in the means over the first and second halves of the lag Δt . This seemingly minor change - technically from "poor man's" to "Haar" wavelets - turns out to make a huge difference since for example, it is adequate for analysing temperatures from seconds to hundreds of millions of years yet

  20. Numerical techniques in linear duct acoustics. [finite difference and finite element analyses

    Science.gov (United States)

    Baumeister, K. J.

    1980-01-01

    Both finite difference and finite element analyses of small amplitude (linear) sound propagation in straight and variable area ducts with flow, as might be found in a typical turboject engine duct, muffler, or industrial ventilation system, are reviewed. Both steady state and transient theories are discussed. Emphasis is placed on the advantages and limitations associated with the various numerical techniques. Examples of practical problems are given for which the numerical techniques have been applied.

  1. Climate Prediction Center (CPC) US daily temperature analyses

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The U.S. daily temperature analyses are maps depicting various temperature quantities utilizing daily maximum and minimum temperature data across the US. Maps are...

  2. X-ray CT analyses, models and numerical simulations: a comparison with petrophysical analyses in an experimental CO2 study

    Science.gov (United States)

    Henkel, Steven; Pudlo, Dieter; Enzmann, Frieder; Reitenbach, Viktor; Albrecht, Daniel; Ganzer, Leonhard; Gaupp, Reinhard

    2016-06-01

    An essential part of the collaborative research project H2STORE (hydrogen to store), which is funded by the German government, was a comparison of various analytical methods for characterizing reservoir sandstones from different stratigraphic units. In this context Permian, Triassic and Tertiary reservoir sandstones were analysed. Rock core materials, provided by RWE Gasspeicher GmbH (Dortmund, Germany), GDF Suez E&P Deutschland GmbH (Lingen, Germany), E.ON Gas Storage GmbH (Essen, Germany) and RAG Rohöl-Aufsuchungs Aktiengesellschaft (Vienna, Austria), were processed by different laboratory techniques; thin sections were prepared, rock fragments were crushed and cubes of 1 cm edge length and plugs 3 to 5 cm in length with a diameter of about 2.5 cm were sawn from macroscopic homogeneous cores. With this prepared sample material, polarized light microscopy and scanning electron microscopy, coupled with image analyses, specific surface area measurements (after Brunauer, Emmet and Teller, 1938; BET), He-porosity and N2-permeability measurements and high-resolution microcomputer tomography (μ-CT), which were used for numerical simulations, were applied. All these methods were practised on most of the same sample material, before and on selected Permian sandstones also after static CO2 experiments under reservoir conditions. A major concern in comparing the results of these methods is an appraisal of the reliability of the given porosity, permeability and mineral-specific reactive (inner) surface area data. The CO2 experiments modified the petrophysical as well as the mineralogical/geochemical rock properties. These changes are detectable by all applied analytical methods. Nevertheless, a major outcome of the high-resolution μ-CT analyses and following numerical data simulations was that quite similar data sets and data interpretations were maintained by the different petrophysical standard methods. Moreover, the μ-CT analyses are not only time saving, but also non

  3. Arctic Climate Change Analysed By Two 30-year Scenario Regional Climate Model Runs

    Science.gov (United States)

    Kiilsholm, S.; Christensen, J. H.

    High-resolution climate change simulations for an area covering the entire Arctic have been conducted with the regional climate model (RCM) HIRHAM. The emission sce- narios used were the IPCC SRES1 marker scenarios A2 and B2. Three 30-year time slice experiments were conducted with HIRHAM for periods representing present-day (1961-1990) and the future (2071-2100) in the two scenarios. Changes of the climate between these two periods will be presented with special emphasize on the climate of Greenland.

  4. Numerical code 'AEOLUS-E1' for analysing free-boundary resistive MHD mode

    International Nuclear Information System (INIS)

    Numerical code 'AEOLUS-E1' for analysing a free-boundary resistive MHD mode in a tokamak is developed. Reduced set of the resistive MHD equation is solved as a single-helicity free-boundary problem based on 'pseudo-vacuum' model in a cylindrical geometry. The code can solve problems including effects of coupling to external circuit and interaction between plasma and limiter. (author)

  5. Effect of spatial variability on the slope stability using Random Field Numerical Limit Analyses

    OpenAIRE

    Kasama, Kiyonobu; Whittle, Andrew

    2015-01-01

    This paper presents a probabilistic approach to evaluating the geotechnical stability problem by incorporating the stochastic spatial variability of soil property within the numerical limit analyses (NLAs). The undrained shear strength and unit weight of soil are treated as a random field which is characterized by a log-normal distribution and a spatial correlation length. The current calculations use a Cholesky Decomposition technique to incorporate these random properties in NLAs. The Rando...

  6. From Global Climate Model Projections to Local Impacts Assessments: Analyses in Support of Planning for Climate Change

    Science.gov (United States)

    Snover, A. K.; Littell, J. S.; Mantua, N. J.; Salathe, E. P.; Hamlet, A. F.; McGuire Elsner, M.; Tohver, I.; Lee, S.

    2010-12-01

    Assessing and planning for the impacts of climate change require regionally-specific information. Information is required not only about projected changes in climate but also the resultant changes in natural and human systems at the temporal and spatial scales of management and decision making. Therefore, climate impacts assessment typically results in a series of analyses, in which relatively coarse-resolution global climate model projections of changes in regional climate are downscaled to provide appropriate input to local impacts models. This talk will describe recent examples in which coarse-resolution (~150 to 300km) GCM output was “translated” into information requested by decision makers at relatively small (watershed) and large (multi-state) scales using regional climate modeling, statistical downscaling, hydrologic modeling, and sector-specific impacts modeling. Projected changes in local air temperature, precipitation, streamflow, and stream temperature were developed to support Seattle City Light’s assessment of climate change impacts on hydroelectric operations, future electricity load, and resident fish populations. A state-wide assessment of climate impacts on eight sectors (agriculture, coasts, energy, forests, human health, hydrology and water resources, salmon, and urban stormwater infrastructure) was developed for Washington State to aid adaptation planning. Hydro-climate change scenarios for approximately 300 streamflow locations in the Columbia River basin and selected coastal drainages west of the Cascades were developed in partnership with major water management agencies in the Pacific Northwest to allow planners to consider how hydrologic changes may affect management objectives. Treatment of uncertainty in these assessments included: using “bracketing” scenarios to describe a range of impacts, using ensemble averages to characterize the central estimate of future conditions (given an emissions scenario), and explicitly assessing

  7. Numerical modeling of shoreline undulations part 1: Constant wave climate

    DEFF Research Database (Denmark)

    Kærgaard, Kasper Hauberg; Fredsøe, Jørgen

    2013-01-01

    This paper presents a numerical study of the non-linear development of alongshore undulations up to fully developed quasi-steady equilibrium. A numerical model which describes the longshore sediment transport along arbitrarily shaped shorelines is applied, based on a spectral wave model, a depth...... integrated flow model, a wave-phase resolving sediment transport description and a one-line shoreline model.First the length of the shoreline undulations is determined in the linear regime using a stability analysis. Next the further evolution from the linear to the fully non-linear regime is described. In...

  8. Evaluation of fracture toughness of copper thin films by combining numerical analyses and experimental tests

    International Nuclear Information System (INIS)

    In this paper, a method of combining numerical analyses and experimental tests is used to evaluate fracture toughness of copper thin films of 15μm thickness. Far field loadings of a global local finite element model are inversely estimated by matching crack opening profiles in experiments with numerical results. The fracture toughness is then evaluated using the J integral for cracks in thin films under far field loadings. In experiments, Cu thin films attached to Aluminum sheets are loaded indirectly, and crack opening profiles are observed by microscope camera. Stress versus strain curves of Cu thin films are obtained through micro tensile tests, and the grain size of Cu thin films is observed by TEM analysis. The results show that the fracture toughness of Cu thin films with 500nm∼1μm sized grains is 6,962J/m'2'

  9. Climatic trends in the Amazonian area of Ecuador: Classical and multifractal analyses

    Science.gov (United States)

    Millán, H.; Kalauzi, A.; Llerena, G.; Sucoshañay, J.; Piedra, D.

    The climate evolution and change in the Amazonian area is very important at least at a continental scale involving Latin America where more than 550 million people live. The objective of the present study was to investigate, from an environmental perspective, the climatic trends in the Amazonian area of continental Ecuador. We performed both classical and multifractal analyses of these trends on four climatic variables (maximum and minimum temperature, evaporation and evaporation/precipitation ratio). Data were collected from Puyo meteorological station, Pastaza Province, Ecuador. Data sets covered 31 years (from January 1974 to September 2005). Each time series consisted of 380 months. Piecewise regression analyses with breaking point showed two regimes with a cutoff ranging from t = 80 months (maximum and minimum temperature) to t = 133 months for the evaporation pattern (determination coefficient ≥ 0.979) while the multifractal analyses showed an increasing complexity within each climatic variable. All the considered climatic variables showed an increase since 1974 to approximately 1985. After that some type of smoother increase was observed.

  10. PROGRESS IN THE STUDY OF RETROSPECTIVE NUMERICAL SCHEME AND THE CLIMATE PREDICTION

    Institute of Scientific and Technical Information of China (English)

    DONG Wenjie; CHOU Jieming; FENG Guolin

    2004-01-01

    The retrospective numerical scheme (RNS) is a numerical computation scheme designed for multiple past value problems of the initial value in mathematics and considering the selfmemory property of the system in physics. This paper briefly presents the historical background of RNS, elaborates the relation of the scheme with other difference schemes and other meteorological prediction methods, and introduces the application of RNS to the regional climatic self-memory model,simplified climate model, barotropic model, spectral model, and mesoscale model. At last, the paper sums up and points out the application perspective of the scheme and the direction for the future study.

  11. A new look at numerical analyses of free-edge stresses in composite laminates

    Science.gov (United States)

    Raju, I. S.; Whitcomb, J. D.; Goree, J. G.

    1980-01-01

    The edge stress problem for a + or - 45 deg graphite/epoxy laminate was examined. The reliability of the displacement formulated finite element method in analyzing the edge stress problem was investigated. Analyses of two well known elasticity problems, one involving a stress discontinuity and one a singularity, showed that the finite element analysis yields accurate stress distributions everywhere except in two elements closest to the stress discontinuity of singularity. Stress distributions for a + or - 45 deg laminate showed the same behavior near the singularity found in the well known problems with exact solutions. The displacement formulated finite element method appears to be a highly accurate technique for calculating interlaminar stress in composite laminates. The disagreement among the numerical methods was attributed to the unsymmetric stress tensor at the singularity.

  12. Analytical and numerical analyses of an unconfined aquifer test considering unsaturated zone characteristics

    Science.gov (United States)

    Moench, A.F.

    2008-01-01

    A 7-d, constant rate aquifer test conducted by University of Waterloo researchers at Canadian Forces Base Borden in Ontario, Canada, is useful for advancing understanding of fluid flow processes in response to pumping from an unconfined aquifer. Measured data include not only drawdown in the saturated zone but also volumetric soil moisture measured at various times and distances from the pumped well. Analytical analyses were conducted with the model published in 2001 by Moench and colleagues, which allows for gradual drainage but does not include unsaturated zone characteristics, and the model published in 2006 by Mathias and Butler, which assumes that moisture retention and relative hydraulic conductivity (RHC) in the unsaturated zone are exponential functions of pressure head. Parameters estimated with either model yield good matches between measured and simulated drawdowns in piezometers. Numerical analyses were conducted with two versions of VS2DT: one that uses traditional Brooks and Corey functional relations and one that uses a RHC function introduced in 2001 by Assouline that includes an additional parameter that accounts for soil structure and texture. The analytical model of Mathias and Butler and numerical model of VS2DT with the Assouline model both show that the RHC function must contain a fitting parameter that is different from that used in the moisture retention function. Results show the influence of field-scale heterogeneity and suggest that the RHC at the Borden site declines more rapidly with elevation above the top of the capillary fringe than would be expected if the parameters were to reflect local- or core-scale soil structure and texture.

  13. Stable carbon isotope analyses in sediments and its implications for reconstructing climatic and environmental changes

    International Nuclear Information System (INIS)

    The relative significance of the 20th-century climatic and environmental changes must be assessed form the long-term global-scale perspective available from a spectrum of proxy histories. In many cases geochemical proxies in sediments are needed to supplement the established use of the stable isotope analyses for paleotemperature and paleo-hydrological modeling so as to understand the past environment conditions and evaluate predictive models of climate. The stable carbon isotope fractionation during photosynthesis and the system CO2 (gas)-CO2-(aqueous)-HCO3- (aqueous) are reviewed; and application of the stable carbon isotope to reconstruction of palaeo-climatic and palaeo-environmental changes, especially CO2 levels during the late Quaternary are discussed

  14. Numerical Modeling for Flood Mapping under Climate Change Impacts: Transboundary Dniester River Study

    Science.gov (United States)

    Zheleznyak, Mark; Kolomiets, Pavlo; Dzjuba, Natalia; Ievgen, Ievgen; Sorokin, Maxim; Denisov, Nickolai; Ischuk, Oleksiy; Koeppel, Sonja

    2015-04-01

    The Dniester river is shared by Ukraine and Moldova. Ukraine being both upstream and downstream of Moldova. The basin is especially suffering from heavy floods, often with transboundary impacts: in Ukraine, disastrous floods in July 2008, which were possibly partly caused or exacerbated by climate change. Within the UNECE | ENVSEC project "Reducing vulnerability to extreme floods and climate change in the Dniester river basin" the numerical flood risks mapping for several "hot spots" along the Dniester river was initiated Two transboundary sites: "Mohyliv Podylskiy- Ataki" and "Dubossary HPP-, Mayaki" (in the delta zone) were chosen for flood risk modelling/mapping. . Floodplain inundation at Mohyliv Podylskiy- Ataki during historical and projected extreme floods scenarios is simulated by 2D model COASTOX -UN based on the numerical solution of shallow water equations on unstructured grid. The scenario of extreme flood, July 2008 that caused hazardous flooding of the riverside areas of Mohyliv Podylskiy has been used for model verification and calibration. The floodmarks of the inundated in 2008 streets have been collected and GIS processed to be used together with the data from the city's water gage station for model testing. The comparison of the simulated dynamics of floodplain inundation during 2008 flood with the observed data show good accuracy of the model. The technologies of the flood modeling and GIS based risk assessments verified for this site are implemented for analyses of the vulnerability to extreme floods for Q=7600 m3 / sec inflow to Dniester reservoir ( 1% flood for contemporary climate assessment) and for Q=8700 m3 / sec. that is considered as projection of 1% flood maximum for XXI century The detailed flood mapping was provided for all cases and was shown that 13% increase in water elevation for future extreme flood scenario will provide at 20% increasing of flooded areas in Mohilev Podolsky. For the site Dubossary NPP in Moldova downstream till

  15. Influence of external climate forcing on coastal upwelling systems analysed in ensemble of past millennium climate simulations

    Science.gov (United States)

    Tim, Nele; Zorita, Eduardo; Hünicke, Birgit; Yi, Xin; Emeis, Kay

    2016-04-01

    Eastern Boundary Upwelling Systems are highly productive coastal ocean areas where nutrient rich, cold water upwells by the action of favorable winds. Observations over the 20th century and ocean sediment records, which may be indicative of upwelling, display an intensification due to stronger external climate forcing, such as increasing greenhouse gas concentrations or changes in solar irradiance. This intensification is compatible with the hypothesis put forward by Bakun (1990) that a stronger external radiative forcing should lead to a more intense coastal upwelling. Here, we analyze ensemble of simulations covering the past millennium with the aim of identifying and quantifying the role of external climate forcing on upwelling in the major Eastern Boundary Upwelling System. We analyse the decadal variability and centennial trends of upwelling in ensemble of simulations with the global climate model MPI-ESM covering the past millennium, the last 150 years and the next 100 years. The future simulations were driven by three IPCC scenarios of concentrations of anthropogenic greenhouse gases, RCP2.5, RCP4.5 and RCP 8.5. For the past millennium and the last 150 years, coastal upwelling does not show any imprint of external forcing. This result indicates that chaotic internal variability has dominated upwelling intensity in major upwelling regions over the last thousand years and even since industrialisation up to present. For the 21st century, all ensemble members show a consistent and significant intensification of upwelling in the strongest scenario RCP8.5 for the Benguela upwelling region, consistent and significant weakening for Morocco and California, and no significant change for the Peruvian upwelling. Weaker scenarios do not produce consistent long-term trends that are replicated in all ensemble members. The results are confirmed by analysing another ensemble of past millennium simulations with the model CESM-CAM5 (Community Earth System Model

  16. Estimation of the mean depth of boreal lakes for use in numerical weather prediction and climate modelling

    Directory of Open Access Journals (Sweden)

    Margarita Choulga

    2014-03-01

    Full Text Available Lakes influence the structure of the atmospheric boundary layer and, consequently, the local weather and local climate. Their influence should be taken into account in the numerical weather prediction (NWP and climate models through parameterisation. For parameterisation, data on lake characteristics external to the model are also needed. The most important parameter is the lake depth. Global database of lake depth GLDB (Global Lake Database is developed to parameterise lakes in NWP and climate modelling. The main purpose of the study is to upgrade GLDB by use of indirect estimates of the mean depth for lakes in boreal zone, depending on their geological origin. For this, Tectonic Plates Map, geological, geomorphologic maps and the map of Quaternary deposits were used. Data from maps were processed by an innovative algorithm, resulting in 141 geological regions where lakes were considered to be of kindred origin. To obtain a typical mean lake depth for each of the selected regions, statistics from GLDB were gained and analysed. The main result of the study is a new version of GLDB with estimations of the typical mean lake depth included. Potential users of the product are NWP and climate models.

  17. Thermal-hydraulics numerical analyses of Pebble Bed Advanced High Temperature Reactor hot channel

    International Nuclear Information System (INIS)

    Background: The thermal hydraulics behavior of the Pebble Bed Advanced High Temperature Reactor (PB-AHTR) hot channel was studied. Purpose: We aim to analyze the thermal-hydraulics behavior of the PB-AHTR, such as pressure drop, temperature distribution of coolant and pebble bed as well as thermal removal capacity in the condition of loss of partial coolant. Methods: We used a modified FLUENT code which was coupled with a local non-equilibrium porous media model by introducing a User Defined Scalar (UDS) in the calculation domain of the reactor core and subjoining different resistance terms (Ergun and KTA) to calculate the temperature of coolant, solid phase of pebble bed and pebble center in the core. Results: Computational results showed that the resistance factor has great influence on pressure drop and velocity distribution, but less impact on the temperature of coolant, solid phase of pebble bed and pebble center. We also confirmed the heat removal capacity of the PB-AHTR in the condition of nominal and loss of partial coolant conditions. Conclusion: The numerical analyses results can provide a useful proposal to optimize the design of PB-AHTR. (authors)

  18. Interaction Between Typhoon and Western Pacific Subtropical Anticyclone:Data Analyses and Numerical Experiments

    Institute of Scientific and Technical Information of China (English)

    Ren Suling; LIU Yimin; WU Guoxiong

    2008-01-01

    Three kinds of typhoons with distinct tracks are sorted based on a set of typhoon data from 1958 to 1998.The results of composite analyses confirln that difierent typhoon tracks correspond to ditierent patterns of the subtropical anticyclone over the western Pacific(SAWP).When the tracks are westward,the SAWP is strong,with a zonal form,and stretches westward;when the tracks are recurring,the main body of the SAWP shifts eastward and breaks near 160°E;and When the tracks are northward,the SAWP is located far east of its normal position.Based on the above result,two different initial fields are configured,one has a zonal and strong SAWP,and the other has a meridional and weak SAWP.By using the GOALS R42L9 climate model,a temperature disturbance is added into these two difierent initial fields to force the formation of a typhoon.Westward and northward tracked typhoons are well simulated,thus verifying that different patterns of the SAWP have different effects on typhoon tracks.Results also show that typhoons can induce barotropic Rossby waves propagating to the mid and high latitudes.Under different background zonal flows,the wave trains triggered by the typhoons of westward and northward tracks are also different,and their effects on the mid and high latitude circulations and the SAWP are difierent.Compared to a northward tracked typhoon,a westward tracked typhoon is able to induce positive geopotential height anomaly to its north and northwest,resulting in the SAWP strengthening and developing westward.

  19. Simulating infectious disease risk based on climatic drivers: from numerical weather prediction to long term climate change scenario

    Science.gov (United States)

    Caminade, C.; Ndione, J. A.; Diallo, M.; MacLeod, D.; Faye, O.; Ba, Y.; Dia, I.; Medlock, J. M.; Leach, S.; McIntyre, K. M.; Baylis, M.; Morse, A. P.

    2012-04-01

    Climate variability is an important component in determining the incidence of a number of diseases with significant health and socioeconomic impacts. In particular, vector born diseases are the most likely to be affected by climate; directly via the development rates and survival of both the pathogen and the vector, and indirectly through changes in the surrounding environmental conditions. Disease risk models of various complexities using different streams of climate forecasts as inputs have been developed within the QWeCI EU and ENHanCE ERA-NET project frameworks. This work will present two application examples, one for Africa and one for Europe. First, we focus on Rift Valley fever over sub-Saharan Africa, a zoonosis that affects domestic animals and humans by causing an acute fever. We show that the Rift Valley fever outbreak that occurred in late 2010 in the northern Sahelian region of Mauritania might have been anticipated ten days in advance using the GFS numerical weather prediction system. Then, an ensemble of regional climate projections is employed to model the climatic suitability of the Asian tiger mosquito for the future over Europe. The Asian tiger mosquito is an invasive species originally from Asia which is able to transmit West Nile and Chikungunya Fever among others. This species has spread worldwide during the last decades, mainly through the shipments of goods from Asia. Different disease models are employed and inter-compared to achieve such a task. Results show that the climatic conditions over southern England, central Western Europe and the Balkans might become more suitable for the mosquito (including the proviso that the mosquito has already been introduced) to establish itself in the future.

  20. Experimental and numerical evaluation of a solar passive cooling system under hot and humid climatic conditions

    Energy Technology Data Exchange (ETDEWEB)

    Rincon, Jose; Almao, Nastia [Universidad del Zulia, Lab. de Simulacion Computacional, Zulia (Venezuela); Gonzalez, Eduardo [Universidad del Zulia, Inst. de Investigaciones de la Facultad de Arquitectura, Zulia (Venezuela)

    2001-07-01

    The thermal performance of a solar passive cooling system (SPCS) under a hot and humid climate is experimentally and numerically evaluated. The experimental data were obtained from two full scale cells, with identical walls, but different roof configurations. One cell has a highly-insulated roof and the other has an SPCS incorporated consisting of a thermal mass (water), which is cooled by evaporation and long wave nocturnal radiation. The study was conducted taking into account the local climatic conditions of Maracaibo, a tropical city located in Venezuela. The numerical evaluation was accomplished using the computational code 'EVITA' which is based on the finite volume approach with high order bounded treatment of the convective terms. A PISO-like solution algorithm is used to solve the transient form of the continuity, momentum and energy equations. It has been demonstrated experimentally and numerically that under a hot and humid climate, it is possible to keep the indoor temperature below the outdoor temperature, using a passive cooling technique of a roof pond. The numerical results obtained using the model have demonstrated that the computational code used is a suitable cost-efficient alternative for the thermal performance evaluation of SPCS. (Author)

  1. Constraint envelope analyses of macroecological patterns reveal climatic effects on Pleistocene mammal extinctions

    Science.gov (United States)

    Lima-Ribeiro, Matheus S.; Hortal, Joaquín; Varela, Sara; Diniz-Filho, José Alexandre F.

    2014-07-01

    Quantitative analysis of macroecological patterns for late Pleistocene assemblages can be useful for disentangling the causes of late Quaternary extinctions (LQE). However, previous analyses have usually assumed linear relationships between macroecological traits, such as body size and range size/range shift, that may have led to erroneous interpretations. Here, we analyzed mammalian datasets to show how macroecological patterns support climate change as an important driver of the LQE, which is contrary to previous analyses that did not account for more complex relationships among traits. We employed quantile regression methods that allow a detailed and fine-tuned quantitative analysis of complex macroecological patterns revealed as polygonal relationships (i.e., constraint envelopes). We showed that these triangular-shaped envelopes that describe the macroecological relationship between body size and geographical range shift reflect nonrandom extinction processes under which the large-bodied species are more prone to extinction during events of severe habitat loss, such as glacial/interglacial transitions. Hence, we provide both a theoretical background and methodological framework to better understand how climate change induces body size-biased species sorting and shapes complex macroecological patterns.

  2. Atmospheric gradients from GNSS, VLBI, and DORIS analyses and from Numerical Weather Models during CONT14

    Science.gov (United States)

    Heinkelmann, Robert; Dick, Galina; Nilsson, Tobias; Soja, Benedikt; Wickert, Jens; Zus, Florian; Schuh, Harald

    2015-04-01

    Observations from space-geodetic techniques are nowadays increasingly used to derive atmospheric information for various commercial and scientific applications. A prominent example is the operational use of GNSS data to improve global and regional weather forecasts, which was started in 2006. Atmosphere gradients describe the azimuthal asymmetry of zenith delays. Estimates of geodetic and other parameters significantly improve when atmosphere gradients are determined in addition. Here we assess the capability of several space geodetic techniques (GNSS, VLBI, DORIS) to determine atmosphere gradients of refractivity. For this purpose we implement and compare various strategies for gradient estimation, such as different values for the temporal resolution and the corresponding parameter constraints. Applying least squares estimation the gradients are usually deterministically modelled as constants or piece-wise linear functions. In our study we compare this approach with a stochastic approach modelling atmosphere gradients as random walk processes and applying a Kalman Filter for parameter estimation. The gradients, derived from space geodetic techniques are verified by comparison with those derived from Numerical Weather Models (NWM). These model data were generated using raytracing calculations based on European Centre for Medium-Range Weather Forecast (ECMWF) and National Centers for Environmental Prediction (NCEP) analyses with different spatial resolutions. The investigation of the differences between the ECMWF and NCEP gradients hereby in addition allow for an empirical assessment of the quality of model gradients and how suitable the NWM data are for verification. CONT14 (2014-05-06 until 2014-05-20) is the youngest two week long continuous VLBI campaign carried out by IVS (International VLBI Service for Geodesy and Astrometry). It presents the state-of-the-art VLBI performance in terms of number of stations and number of observations and presents thus an

  3. Combined analytical and numerical approaches in Dynamic Stability analyses of engineering systems

    Science.gov (United States)

    Náprstek, Jiří

    2015-03-01

    Dynamic Stability is a widely studied area that has attracted many researchers from various disciplines. Although Dynamic Stability is usually associated with mechanics, theoretical physics or other natural and technical disciplines, it is also relevant to social, economic, and philosophical areas of our lives. Therefore, it is useful to occasionally highlight the general aspects of this amazing area, to present some relevant examples and to evaluate its position among the various branches of Rational Mechanics. From this perspective, the aim of this study is to present a brief review concerning the Dynamic Stability problem, its basic definitions and principles, important phenomena, research motivations and applications in engineering. The relationships with relevant systems that are prone to stability loss (encountered in other areas such as physics, other natural sciences and engineering) are also noted. The theoretical background, which is applicable to many disciplines, is presented. In this paper, the most frequently used Dynamic Stability analysis methods are presented in relation to individual dynamic systems that are widely discussed in various engineering branches. In particular, the Lyapunov function and exponent procedures, Routh-Hurwitz, Liénard, and other theorems are outlined together with demonstrations. The possibilities for analytical and numerical procedures are mentioned together with possible feedback from experimental research and testing. The strengths and shortcomings of these approaches are evaluated together with examples of their effective complementing of each other. The systems that are widely encountered in engineering are presented in the form of mathematical models. The analyses of their Dynamic Stability and post-critical behaviour are also presented. The stability limits, bifurcation points, quasi-periodic response processes and chaotic regimes are discussed. The limit cycle existence and stability are examined together with their

  4. Global terrestrial water storage connectivity revealed using complex climate network analyses

    Directory of Open Access Journals (Sweden)

    A. Y. Sun

    2015-04-01

    Full Text Available Terrestrial water storage (TWS exerts a key control in global water, energy, and biogeochemical cycles. Although certain causal relationships exist between precipitation and TWS, the latter also reflects impacts of anthropogenic activities. Thus, quantification of the spatial patterns of TWS will not only help to understand feedbacks between climate dynamics and hydrologic cycle, but also provide new model calibration constraints for improving the current land surface models. In this work, the connectivity of TWS is quantified using the climate network theory, which has received broad attention in the climate modeling community in recent years. Complex networks of TWS anomalies are built using two global TWS datasets, a remote-sensing product that is obtained from the Gravity Recovery and Climate Experiment (GRACE satellite mission, and a model-generated dataset from the global land data assimilation system's NOAH model (GLDAS-NOAH. Both datasets have 1 ° × 1 ° resolutions and cover most global land areas except for permafrost regions. TWS networks are built by first quantifying pairwise correlation among all valid TWS anomaly time series, and then applying a statistical cutoff threshold to retain only the most important features in the network. Basinwise network connectivity maps are used to illuminate connectivity of individual river basins with other regions. The constructed network degree centrality maps show TWS hotspots around the globe and the patterns are consistent with recent GRACE studies. Parallel analyses of networks constructed using the two datasets indicate that the GLDAS-NOAH model captures many of the spatial patterns shown by GRACE, although significant discrepancies exist in some regions. Thus, our results provide important insights for constraining land surface models, especially in data sparse regions.

  5. Analysing bifurcations encountered in numerical modelling of current transfer to cathodes of dc glow and arc discharges

    Energy Technology Data Exchange (ETDEWEB)

    Almeida, P G C; Benilov, M S; Cunha, M D; Faria, M J [Departamento de Fisica, Universidade da Madeira, Largo do Municipio, 9000 Funchal (Portugal)

    2009-10-07

    Bifurcations and/or their consequences are frequently encountered in numerical modelling of current transfer to cathodes of gas discharges, also in apparently simple situations, and a failure to recognize and properly analyse a bifurcation may create difficulties in the modelling and hinder the understanding of numerical results and the underlying physics. This work is concerned with analysis of bifurcations that have been encountered in the modelling of steady-state current transfer to cathodes of glow and arc discharges. All basic types of steady-state bifurcations (fold, transcritical, pitchfork) have been identified and analysed. The analysis provides explanations to many results obtained in numerical modelling. In particular, it is shown that dramatic changes in patterns of current transfer to cathodes of both glow and arc discharges, described by numerical modelling, occur through perturbed transcritical bifurcations of first- and second-order contact. The analysis elucidates the reason why the mode of glow discharge associated with the falling section of the current-voltage characteristic in the solution of von Engel and Steenbeck seems not to appear in 2D numerical modelling and the subnormal and normal modes appear instead. A similar effect has been identified in numerical modelling of arc cathodes and explained.

  6. Numerical and experimental analyses of resin infusion manufacturing processes of composite materials

    CERN Document Server

    Wang, Peng; Molimard, Jérôme; Vautrin, Alain; Minni, Jean-Christophe; 10.1177/0021998311421990

    2012-01-01

    Liquid resin infusion (LRI) processes are promising manufacturing routes to produce large, thick, or complex structural parts. They are based on the resin flow induced, across its thickness, by a pressure applied onto a preform/resin stacking. However, both thickness and fiber volume fraction of the final piece are not well controlled since they result from complex mechanisms which drive the transient mechanical equilibrium leading to the final geometrical configuration. In order to optimize both design and manufacturing parameters, but also to monitor the LRI process, an isothermal numerical model has been developed which describes the mechanical interaction between the deformations of the porous medium and the resin flow during infusion.1, 2 With this numerical model, it is possible to investigate the LRI process of classical industrial part shapes. To validate the numerical model, first in 2D, and to improve the knowledge of the LRI process, this study details a comparison between numerical simulations and...

  7. A numerical model to analyse the impact between piping and gapped restraints

    International Nuclear Information System (INIS)

    An algorithm to solve the impact between deformable bodies and rigid gapped restrains is presented. This kind of problem occurs in structures of nuclear power plants. This algorithm combines the Newmark method with an impact model which simulates the impulsive force as a retangular pulse. When several restraints are presented the equilibrium and the unilateral conditions are simultaneously attained by means of an iterative scheme which deals with a reduced flexibility matrix, of the order of the number of unilateral restraints, to avoid the use of the whole matrix of the system. Some numerical examples solved with the proposed algorithm show that no numerical instabilities occur. (author)

  8. Retrieval of temperature profiles from CHAMP for climate monitoring: intercomparison with Envisat MIPAS and GOMOS and different atmospheric analyses

    Directory of Open Access Journals (Sweden)

    A. Gobiet

    2007-02-01

    temperature or pressure value derived from meteorological analyses is prone to introduce biases from the initialisation data to the retrieved temperatures down to below 25 km. Above 30 to 35 km, GNSS RO delivers a considerable amount of observed information up to around 40 km, which is particularly interesting for numerical weather prediction (NWP systems, where direct assimilation of non-initialized (a priori-free observed RO bending angles is thus the method of choice. The results underline the value of RO for climate applications.

  9. NUMERICAL SIMULATION ANALYSES ON REINFORCEMENT FUNCTION OF THE TENSIONED AND GROUTED BOLTS

    Institute of Scientific and Technical Information of China (English)

    邹喜正; 李华祥

    1998-01-01

    The purpose of the paper is to calculate the equivalent mechanics parameters of reinforced surroundings, which is based on the assume that the reinforcement of bolts is equivalent to the improvement of mechanics parameters of surroundings and combines with site engineering practice. Use numerical simulation analysis to study the reinforcement mechanism of full length bolts, thus to provide theoretical bases for bolting design.

  10. The Virtual Institute of Integrated Climate and Landscape Evolution Analyses - ICLEA

    Science.gov (United States)

    Schwab, Markus; Brauer, Achim; Błaszkiewicz, Mirosław; Raab, Thomas; Wilmking, Martin; Blume, Theresa; Iclea Team

    2014-05-01

    The GFZ, Greifswald University and the Brandenburg University of Technology together with their partner the Polish Academy of Sciences strive for focusing their research capacities and expertise in a Helmholtz Virtual Institute for Integrated Climate and Landscape Evolution Analyses (ICLEA). The Coordination Team is based at the GFZ in Potsdam and consists of a permanent scientific manager and administrative personnel. ICLEA offers young researchers an interdisciplinary and structured education and promote their early independence through coaching and mentoring. Postdoctoral rotation positions at the ICLEA partner institutions ensure mobility of young researchers and promote dissemination of information and expertise between disciplines. Training, Research and Analytical workshops between research partners of the ICLEA virtual institute are another important measure to qualify young researchers. The long-term mission of the Virtual Institute is to provide a substantiated data basis for sustained environmental maintenance based on a profound process understanding at all relevant time scales. Aim is to explore processes of climate and landscape evolution in an historical cultural landscape extending from northeastern Germany into northwestern Poland. The northern-central European lowlands will be facilitated as a natural laboratory providing an ideal case for utilizing a systematic and holistic approach. In ICLEA five complementary work packages (WP) are established according to the key research aspects. WP 1 focus on monitoring mainly hydrology and soil moisture as well as meteorological parameters. WP 2 is linking present day and future monitoring data with the most recent past through analysing satellite images. This WP will further provide larger spatial scales. WP 3-5 focus on different natural archives to obtain a broad variety of high quality proxy data. Tree rings provide sub-seasonal data for the last centuries up to few millennia, varved lake sediments

  11. Numerical Experiments on the Spin-up Time for Seasonal-Scale Regional Climate Modeling

    Institute of Scientific and Technical Information of China (English)

    ZHONG Zhong; HU Yijia; MIN Jinzhong; XU Honglei

    2007-01-01

    In this paper, the numerical experiments on the issue of spin-up time for seasonal-scale regional climate modeling were conducted with the newly Regional Climate Model (RegCM3), in the case of the abnormal climate event during the summer of 1998 in China. To test the effect of spin-up time on the regional climate simulation results for such abnormal climate event, a total of 11 experiments were performed with different spin-up time from 10 days to 6 months, respectively. The simulation results show that, for the meteorological variables in the atmosphere, the model would be running in "climate mode" after 4-8-day spin-up time, then,it is independent of the spin-up time basically, and the simulation errors are mainly caused by the model's failure in describing the atmospheric processes over the model domain. This verifies again that the regional climate modeling is indeed a lateral boundary condition problem as demonstrated by earlier research work.The simulated mean precipitation rate over each subregion is not sensitive to the spin-up time, but the precipitation scenario is somewhat different for the experiment with different spin-up time, which shows that there exists the uncertainty in the simulation to precipitation scenario, and such a uncertainty exhibits more over the areas where heavy rainfall happened. Generally, for monthly-scale precipitation simulation, aspin-up time of 1 month is enough, whereas a spin-up time of 2 months is better for seasonal-scale one.Furthermore, the relationship between the precipitation simulation error and the advancement/withdrawal of East Asian summer monsoon was analyzed. It is found that the variability of correlation coefficient for precipitation is more significant over the areas where the summer monsoon is predominant. Therefore, the model's capability in reproducing precipitation features is related to the heavy rainfall processes associated with the advancement/withdrawal of East Asian summer monsoon, which suggests

  12. Numerical andexperimental analyses of hydrodynamic performance of a cha- nnel type planing trimaran

    Institute of Scientific and Technical Information of China (English)

    SU Yu-min; WANG Shuo; SHEN Hai-long; DUXin

    2014-01-01

    This paper studies the hydrodynamic performance of a channel type planing trimaran. A numerical simulation is carried out based on a RANS-VOF solver to analyze the hydrodynamic performance of the channel type planing trimaran. A series of hydrodynamic experiments in towing tank were carried out, in which both the running attitude and the resistance performance of the trimaran model were recorded. Some hydrodynamic characteristics of the channel type planning trimaran are shown by the results. Firstly, the resistance declines significantly, with the forward speed across the high-speed resistance peak due to the combined effects of the aerodynamic and hydrodynamic lifts. Secondly, the resistance performance is influenced markedly by the longitudinal positio- ns of centre of the gravity and the displacements. Besides, the pressure distribution on the hull and the two-phase flow in the channel are discussed in the numerical simulations.

  13. Experimental and Numerical Analyses of New Massive Wooden Shear-Wall Systems

    Directory of Open Access Journals (Sweden)

    Luca Pozza

    2014-07-01

    Full Text Available Three innovative massive wooden shear-wall systems (Cross-Laminated-Glued Wall, Cross-Laminated-Stapled Wall, Layered Wall with dovetail inserts were tested and their structural behaviour under seismic action was assessed with numerical simulations. The wall specimens differ mainly in the method used to assemble the layers of timber boards composing them. Quasi-static cyclic loading tests were carried out and then reproduced with a non-linear numerical model calibrated on the test results to estimate the most appropriate behaviour factor for each system. Non-linear dynamic simulations of 15 artificially generated seismic shocks showed that these systems have good dissipative capacity when correctly designed and that they can be assigned to the medium ductility class of Eurocode 8. This work also shows the influence of deformations in wooden panels and base connectors on the behaviour factor and dissipative capacity of the system.

  14. Physical mechanisms involved in grooved flat heat pipes: experimental and numerical analyses

    OpenAIRE

    Lips, S.; Lefevre, F.; Bonjour, J.

    2011-01-01

    An experimental database, obtained with flat plate heat pipes (FPHP) with longitudinal grooves is presented. The capillary pressure measured by confocal microscopy and the temperature field in the wall are presented in various experimental conditions (vapour space thickness, filing ratio, heat transfer rate, tilt angle, fluid). Coupled hydrodynamic and thermal models are developed. Experimental results are compared to results of numerical models. Physical mechanisms involved in grooved heat p...

  15. Numerical Analyses of Electromagnetic Forces on the ITER Blanket Module Shield Block During Major Disruptions

    International Nuclear Information System (INIS)

    Electromagnetic (EM) load is one of the key design drivers for the blanket shield block (SB) and other in-vessel components. In this article, an EM analysis method was developed to address the EM force on the SB. The plasma currents, which vary spatially and temporally, are loaded as a filament at each time point. The standard blanket module No.04 (BM04) under major disruption (MD) is selected to perform the analyses. The analyses results are validated by comparing currents on the passive structure. To better understand the effects of cooling channels and slits on the EM force, the case of SB without cooling channel and the case without slits are calculated to make comparisons. The results show that the slits play an important role in controlling the EM load on SB. (fusion engineering)

  16. Numerical analyses of flow distributions in nuclear fuel assemblies affected by grid deformations

    International Nuclear Information System (INIS)

    Highlights: • Deformed spacer grid of a fuel assembly restricts coolant flow. • CFD analyses are conducted to assess flow redistribution and recovery. • Flow field is analyzed for normal operation, blowdown and reflood phases. • Forty-five times hydraulic diameter is required to recover 95% of flow rate. - Abstract: In the event of a safety shutdown earthquake (SSE) in a nuclear power plant, the spacer grid of the fuel assembly will be deformed as a result of the vibrations. If the flow area in a subchannel is reduced due to the grid deformation, the coolant flow will be restricted and consequently a loss of flow occurs in the affected fuel assembly during the accident. In this study, computational fluid dynamics (CFD) analyses are conducted in order to assess the flow redistribution and flow recovery in fuel assemblies. The real geometries of an outer grid and mixing vane are used in the simulation, and the region including the inner grid is modeled as a porous media zone. The resistance coefficients of the porous media model are determined using CFD analyses. The Reynolds-averaged Navier–Stokes equation with a non-linear turbulence model was used to solve the three-dimensional anisotropic turbulence flow in the rod bundles during normal operation, blowdown, and reflood phases following a loss-of-coolant accident (LOCA). In these analyses, it is assumed that forty percent of the flow area is blocked by grid deformations. The results demonstrate that a downstream distance of 45 times the hydraulic diameter is required for the coolant flow to recover to 95% of the original flow rate in the affected fuel assembly

  17. Responsible Climate Change Adaptation : Exploring, analysing and evaluating public and private responsibilities for urban adaptation to climate change

    NARCIS (Netherlands)

    Mees, Heleen

    2014-01-01

    Cities are vulnerable to climate change. To deal with climate change, city governments and private actors such as businesses and citizens need to adapt to its effects, such as sea level rise, storm surges, intense rainfall and heatwaves. However, adaptation planning and action is often hampered when

  18. Influence of Impeller Geometry on the Unsteady Flow in a Centrifugal Fan: Numerical and Experimental Analyses

    Directory of Open Access Journals (Sweden)

    M. Younsi

    2007-01-01

    Full Text Available The aim of this study is to evaluate the influence of design parameters on the unsteady flow in a forward-curved centrifugal fan and their impact on the aeroacoustic behavior. To do so, numerical and experimental studies have been carried out on four centrifugal impellers designed with various geometrical parameters. The same volute casing has been used to study these impellers. The effects on the unsteady flow behavior related to irregular blade spacing, blade count and radial distance between the impeller periphery and the volute tongue have been studied. The numerical simulations of the unsteady flow have been carried out using computational fluid dynamics (CFD tools based on the unsteady Reynolds averaged Navier Stokes (URANS approach. The study is focused on the unsteadiness induced by the aerodynamic interaction between the volute and the rotating impeller blades. In order to predict the acoustic pressure at far field, the unsteady flow variables provided by the CFD calculations have been used as inputs in the Ffowcs Williams-Hawkings equations (FW-H. The experimental part of this work concerns measurement of aerodynamic performance of the fans using a test bench built according to ISO 5801 (1997 standard. In addition to this, pressure microphones have been flush mounted on the volute tongue surface in order to measure the wall pressure fluctuations. The sound pressure level (SPL measurements have been carried out in an anechoic room in order to remove undesired noise reflections. Finally, the numerical results have been compared with the experimental measurements and a correlation between the wall pressure fluctuations and the far field noise signals has been found.

  19. Numerical analyses of boiling two-phase bubbly flows in pipes with particle tracking method

    International Nuclear Information System (INIS)

    The present study deals with the numerical modeling of two-phase bubbly flows with subcooled boiling in a flow channel using Particle Tracking Method. It is an on-going project whose final aim is to develop a computer code to more accurately predict, and better understand, the Departure from Nuclear Boiling (DNB) under PWR accidental conditions. At the first stage of the present study, this presentation reports the development of bubble dynamics models such as the bubble coalesces/break models and bubble heat transfer models. The validation of the models by comparing simulation results with experimental data in literature is also reported. (author)

  20. Numerical analyses of the effect of SG‐interlayer shear stiffness on the structural performance of reinforced glass beams

    DEFF Research Database (Denmark)

    Louter, C.; Nielsen, Jens Henrik

    2013-01-01

    SentryGlas (SG) interlayer sheets. The current contribution numerically investigates the effect of the SG-interlayer shear stiffness on the overall structural response of the beams. This is done by means of a 3D finite element model in which the individual glass layers, the SG-interlayers and the...... reinforcement are incorporated. In the model, the glass parts are allowed to crack, but all other parts are assumed linear elastic throughout the analyses. By changing the shear modulus of the SG-interlayer in multiple analyses, its contribution to the overall structural performance of the beams – especially at...... the post-breakage stage –is investigated. From the results of the analyses it is observed that the residual load-bearing capacity, i.e. the load-bearing capacity after glass fracture, increases with an increasing shear modulus of the SG-interlayer. Furthermore, the load-displacement response from the...

  1. Numerical analyses of influence of overlying pit excavation on existing tunnels

    Institute of Scientific and Technical Information of China (English)

    郑刚; 魏少伟

    2008-01-01

    The response of existing tunnel due to overlying excavation was studied using 2D FEM (Finite element method). Three typical locations of tunnel with respect to excavation, namely at the central line under the excavation bottom, directly under the base of diaphragm wall and outside of diaphragm, were considered. The variation of tunnel response with the change of location of tunnel was analyzed. The stress path of soil surrounding tunnel during the process of excavation was compared. Numerical analysis results indicate that the underlying tunnels at different locations under the excavation will experience convergence and divergence due to overlying excavation. Moreover, the tunnel located below base of diaphragm wall will experience distortion. The deformation is mainly due to the uneven changes of ground contact pressure on tunnel linings. Both the vertical and horizontal displacement of the tunnel decrease with the increase of the tunnel embedded depth beneath the formation of excavation.

  2. Numerical analyses on cooling process of superconducting insertion quadrupole magnets for BEPC II

    International Nuclear Information System (INIS)

    A pair of superconducting insertion quadrupole magnets (SCQ), and a superconducting solenoid magnets (SSM) were used in the Beijing Electron-Positron Collider Upgrade (BEPC II) in order to reduce the length of the beam, and to increase distinguish and identification ability of the particle. A cryogenic plant of 500 W at 4.5 K was to be built for the operation of the superconducting magnets. The paper described the cooling process for the SCQ and SSM magnets. Two kinds of cooling schemes for SCQ magnets, supercritical helium cooling and subcooled liquid helium cooling, were compared by numerical method. Thermal parameters of two kinds of cooling process were provided. Finally, the design of the subcooler, one of key components was presented. (authors)

  3. A mm-Wave Polarisation Analyser Using LEKIDs: Strategy and Preliminary Numerical Results

    Science.gov (United States)

    Tartari, A.; Belier, B.; Calvo, M.; Cammilleri, V. D.; Monfardini, A.; Piat, M.; Prêle, D.; Smoot, G. F.

    2014-08-01

    The context of this study is the development of polarisation sensitive detectors in view of future Cosmic Microwave Background experiments. Our goal is to demonstrate the possibility to make a mm-wave polarisation analyser at 150 GHz using Lumped Element Kinetic Inductance Detectors (LEKIDs). Although LEKIDs are very attractive for the relative ease of fabrication, they have an intrinsic optical response which is weakly polarisation-senstive, i.e. orthogonal linear polarisations are absorbed with comparable efficiencies (with a separation typically not exceeding few dB). To overcome this difficulty, we achieve a polarised response by means of small () superconducting Nb wire-grids. Each grid is deposited on the rear side of the 300 micron Si substrate, on which 20 nm Al resonators are patterned, so that each pixel may in principle respond as an independent polarisation analyser. Simulations show encouraging results, with a deep (-20 dB) rejection of the unwanted polarisation. Although what we present here is not yet a polarimeter, this pilot study allows us to address some relevant questions that may be crucial in view of a full polarimetric architecture development. In particular, our first prototypes will allow to assess the behaviour of small grids, the interaction between adjacent polarised pixels, and to choose the most suitable resonator geometry. What we present here are preliminary design results about devices which are currently being realised, and soon ready for optical response characterisation.

  4. Numerical analyses of a water pool under loadings caused by a condensation induced water hammer

    International Nuclear Information System (INIS)

    Three-dimensional simulations of a rapidly condensing steam bubble in a water pool have been performed by using the commercial computational fluid dynamics (CFD) code Star-CD. The condensing bubble was modelled by using a mass sink in a single-phase calculation. The pressure load on the wall of the pool was determined and transferred to the structural analyses code ABAQUS. The analyses were done for a test pool at Lappeenranta University of Technology. The structural integrity of the pool during steam experiments was investigated by assuming as a test load the rapid condensation of a steam bubble with a diameter of 20 cm. The mass sink for modelling the collapse of the bubble was deter-mined from the potential theory of incompressible fluid. The rapid condensation of the bubble within 25 ms initiated a strong condensation water hammer. The maximum amplitude of the pressure load on the pool wall was approximately 300 kPa. The loads caused by the high compression waves lasted only about 0.4 ms. The loadings caused by larger bubbles or more rapid collapse could not be calculated with the present method. (au)

  5. Numerical analyses of a water pool under loadings caused by a condensation induced water hammer

    Energy Technology Data Exchange (ETDEWEB)

    Timperi, A.; Paettikangas, T.; Calonius, K.; Tuunanen, J.; Poikolainen, J.; Saarenheimo, A. [VTT Industrial Systems (Finland)

    2004-03-01

    Three-dimensional simulations of a rapidly condensing steam bubble in a water pool have been performed by using the commercial computational fluid dynamics (CFD) code Star-CD. The condensing bubble was modelled by using a mass sink in a single-phase calculation. The pressure load on the wall of the pool was determined and transferred to the structural analyses code ABAQUS. The analyses were done for a test pool at Lappeenranta University of Technology. The structural integrity of the pool during steam experiments was investigated by assuming as a test load the rapid condensation of a steam bubble with a diameter of 20 cm. The mass sink for modelling the collapse of the bubble was deter-mined from the potential theory of incompressible fluid. The rapid condensation of the bubble within 25 ms initiated a strong condensation water hammer. The maximum amplitude of the pressure load on the pool wall was approximately 300 kPa. The loads caused by the high compression waves lasted only about 0.4 ms. The loadings caused by larger bubbles or more rapid collapse could not be calculated with the present method. (au)

  6. Understanding the Flow Physics of Shock Boundary-Layer Interactions Using CFD and Numerical Analyses

    Science.gov (United States)

    Friedlander, David J.

    2013-01-01

    Computational fluid dynamic (CFD) analyses of the University of Michigan (UM) Shock/Boundary-Layer Interaction (SBLI) experiments were performed as an extension of the CFD SBLI Workshop held at the 48th AIAA Aerospace Sciences Meeting in 2010. In particular, the UM Mach 2.75 Glass Tunnel with a semi-spanning 7.75deg wedge was analyzed in attempts to explore key physics pertinent to SBLI's, including thermodynamic and viscous boundary conditions as well as turbulence modeling. Most of the analyses were 3D CFD simulations using the OVERFLOW flow solver, with additional quasi-1D simulations performed with an in house MATLAB code interfacing with the NIST REFPROP code to explore perfect verses non-ideal air. A fundamental exploration pertaining to the effects of particle image velocimetry (PIV) on post-processing data is also shown. Results from the CFD simulations showed an improvement in agreement with experimental data with key contributions including adding a laminar zone upstream of the wedge and the necessity of mimicking PIV particle lag for comparisons. Results from the quasi-1D simulation showed that there was little difference between perfect and non-ideal air for the configuration presented.

  7. Responsible Climate Change Adaptation : Exploring, analysing and evaluating public and private responsibilities for urban adaptation to climate change

    OpenAIRE

    Mees, Heleen

    2014-01-01

    Cities are vulnerable to climate change. To deal with climate change, city governments and private actors such as businesses and citizens need to adapt to its effects, such as sea level rise, storm surges, intense rainfall and heatwaves. However, adaptation planning and action is often hampered when the relevant public and private actors have only vague and ambiguous responsibilities. Some exploration on the issue of public and private responsibilities has been undertaken in the literature, b...

  8. NUMERICAL ANALYSES FOR TREATING DIFFUSION IN SINGLE-, TWO-, AND THREE-PHASE BINARY ALLOY SYSTEMS

    Science.gov (United States)

    Tenney, D. R.

    1994-01-01

    This package consists of a series of three computer programs for treating one-dimensional transient diffusion problems in single and multiple phase binary alloy systems. An accurate understanding of the diffusion process is important in the development and production of binary alloys. Previous solutions of the diffusion equations were highly restricted in their scope and application. The finite-difference solutions developed for this package are applicable for planar, cylindrical, and spherical geometries with any diffusion-zone size and any continuous variation of the diffusion coefficient with concentration. Special techniques were included to account for differences in modal volumes, initiation and growth of an intermediate phase, disappearance of a phase, and the presence of an initial composition profile in the specimen. In each analysis, an effort was made to achieve good accuracy while minimizing computation time. The solutions to the diffusion equations for single-, two-, and threephase binary alloy systems are numerically calculated by the three programs NAD1, NAD2, and NAD3. NAD1 treats the diffusion between pure metals which belong to a single-phase system. Diffusion in this system is described by a one-dimensional Fick's second law and will result in a continuous composition variation. For computational purposes, Fick's second law is expressed as an explicit second-order finite difference equation. Finite difference calculations are made by choosing the grid spacing small enough to give convergent solutions of acceptable accuracy. NAD2 treats diffusion between pure metals which form a two-phase system. Diffusion in the twophase system is described by two partial differential equations (a Fick's second law for each phase) and an interface-flux-balance equation which describes the location of the interface. Actual interface motion is obtained by a mass conservation procedure. To account for changes in the thicknesses of the two phases as diffusion

  9. An anisotropic numerical model for thermal hydraulic analyses: application to liquid metal flow in fuel assemblies

    Science.gov (United States)

    Vitillo, F.; Vitale Di Maio, D.; Galati, C.; Caruso, G.

    2015-11-01

    A CFD analysis has been carried out to study the thermal-hydraulic behavior of liquid metal coolant in a fuel assembly of triangular lattice. In order to obtain fast and accurate results, the isotropic two-equation RANS approach is often used in nuclear engineering applications. A different approach is provided by Non-Linear Eddy Viscosity Models (NLEVM), which try to take into account anisotropic effects by a nonlinear formulation of the Reynolds stress tensor. This approach is very promising, as it results in a very good numerical behavior and in a potentially better fluid flow description than classical isotropic models. An Anisotropic Shear Stress Transport (ASST) model, implemented into a commercial software, has been applied in previous studies, showing very trustful results for a large variety of flows and applications. In the paper, the ASST model has been used to perform an analysis of the fluid flow inside the fuel assembly of the ALFRED lead cooled fast reactor. Then, a comparison between the results of wall-resolved conjugated heat transfer computations and the results of a decoupled analysis using a suitable thermal wall-function previously implemented into the solver has been performed and presented.

  10. Numerical analyses on optical limiting performances of chloroindium phthalocyanines with different substituent positions

    Science.gov (United States)

    Yu-Jin, Zhang; Xing-Zhe, Li; Ji-Cai, Liu; Chuan-Kui, Wang

    2016-01-01

    Optical limiting properties of two soluble chloroindium phthalocyanines with α- and β-alkoxyl substituents in nanosecond laser field have been studied by solving numerically the coupled singlet-triplet rate equation together with the paraxial wave field equation under the Crank-Nicholson scheme. Both transverse and longitudinal effects of the laser field on photophysical properties of the compounds are considered. Effective transfer time between the ground state and the lowest triplet state is defined in reformulated rate equations to characterize dynamics of singlet-triplet state population transfer. It is found that both phthalocyanines exhibit good nonlinear optical absorption abilities, while the compound with α-substituent shows enhanced optical limiting performance. Our ab-initio calculations reveal that the phthalocyanine with α-substituent has more obvious electron delocalization and lower frontier orbital transfer energies, which are responsible for its preferable photophysical properties. Project supported by the National Basic Research Program of China (Grant No. 2011CB808100), the National Natural Science Foundation of China (Grant Nos. 11204078 and 11574082), and the Fundamental Research Funds for the Central Universities of China (Grant No. 2015MS54).

  11. Experimental and numerical analyses of a hydrogen and deuterium storage system

    International Nuclear Information System (INIS)

    Highlights: • Experimental data to develop a real-time tritium storage control system. • Simulation (3D modeling) of real working conditions for long term tritium storage on titanium. • No major differences between the reaction of hydrogen and deuterium on titanium sponge were revealed. -- Abstract: This paper conducts an experiment and a three-dimensional (3D) modeling study for the absorption of hydrogen and deuterium on a storage tank with titanium sponge bed in order to simulate the real working conditions of a tritium storage system prior to tritium service. The 3D model is further numerically implemented and experimentally validated. The model is composed of an energy balance, mass balance and momentum balance and hydriding reaction kinetics. These differential equations are solved using finite element method. The experimental consisting in absorption of hydrogen and deuterium gas was made in batch made, under vacuum condition. Before absorption, an activation of the titanium bed was performed. A number of loading and releasing operations typically required in tritium handling loops were conducted using one bed containing a well determined quantity of titanium sponge. A comparison between theoretical results and experimental data has found that the gas was not uniformly absorbed on the metal bed volume. This work provides an important platform to understand the phenomena during tritium absorption on a titanium storage bed and the development of a real-time tritium storage control system

  12. Numerical analyses of the effect of SG‐interlayer shear stiffness on the structural performance of reinforced glass beams

    DEFF Research Database (Denmark)

    Louter, C.; Nielsen, Jens Henrik

    2013-01-01

    This paper focuses on the numerical modelling of SentryGlas-laminated reinforced glass beams. In these beams, which have been experimentally investigated in preceding research, a stainless steel reinforcement section is laminated at the inner recessed edge of a triple-layer glass beam by means of...... SentryGlas (SG) interlayer sheets. The current contribution numerically investigates the effect of the SG-interlayer shear stiffness on the overall structural response of the beams. This is done by means of a 3D finite element model in which the individual glass layers, the SG-interlayers and the...... the post-breakage stage –is investigated. From the results of the analyses it is observed that the residual load-bearing capacity, i.e. the load-bearing capacity after glass fracture, increases with an increasing shear modulus of the SG-interlayer. Furthermore, the load-displacement response from the...

  13. Theoretical and numerical analyses of a slit-masked chicane for modulated bunch generation

    Science.gov (United States)

    Zhu, X.; Broemmelsiek, D. R.; Shin, Y.-M.

    2015-10-01

    Density modulations on electron beams can improve machine performance of beam-driven accelerators and FELs with resonance beam-wave coupling. The beam modulation is studied with a masked chicane by the analytic model and simulations with the beam parameters of the Fermilab Accelerator Science and Technology (FAST) facility. With the chicane design parameters (bending angle of 18o, bending radius of 0.95 m and R56 ~ -0.19 m) and a nominal beam of 3 ps bunch length, the analytic model showed that a slit-mask with slit period 900 μ m and aperture width 300 μ m induces a modulation of bunch-to-bunch spacing ~ 100 μ m to the bunch with 2.4% correlated energy spread. With the designed slit mask and a 3 ps bunch, particle-in-cell (PIC) simulations, including nonlinear energy distributions, space charge force, and coherent synchrotron radiation (CSR) effect, also result in beam modulation with bunch-to-bunch distance around 100 μ m and a corresponding modulation frequency of 3 THz. The beam modulation has been extensively examined with three different beam conditions, 2.25 ps (0.25 nC), 3.25 ps (1 nC), and 4.75 ps (3.2 nC), by tracking code Elegant. The simulation analysis indicates that the sliced beam by the slit-mask with 3 ~ 6% correlated energy spread has modulation lengths about 187 μ m (0.25 nC), 270 μ m (1 nC) and 325 μ m (3.2 nC). The theoretical and numerical data proved the capability of the designed masked chicane in producing modulated bunch train with micro-bunch length around 100 fs.

  14. Numerical Simulation on Climate Effects of Freezing-Thawing Processes Using CCM3

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    A parameterization of soil freezing-thawing physics for use in the land-surface model of the National Center for Atmospheric Research(NCAR) Community Climate Model(CCM3) is developed and evaluated.The new parameterization scheme has improved the representation of physical processes in the existing land surface model.Numerical simulations using CCM3 with improved land-surface processes and with the original land-surface processes are compared against the NCEP reanalysis.It is found that the CCM3 version using the improved land surface model shows significant improvements in simulating precipitation in China during the summer season,the general circulation over East Asia,and wind fields over the Tibet Plateau.For the summer season,the improved model was able to better simulate the Indian summer monsoon components,including the mean northerly wind in the upper troposphere and mean southerly wind in the lower troposphere.

  15. Introduction and systematic assessment for IAP numerical annual climate prediction system

    Institute of Scientific and Technical Information of China (English)

    CHEN Hong; LIN Zhaohui; ZENG Qingcun

    2003-01-01

    The IAP numerical annual climate prediction system has been presented in this paper. In order to evaluate this annual prediction system, annual ensemble hindcast experiments over a 21-year period from 1980 to 2000 have been done. Systematic assessment shows that this annual prediction system has higher predictability for summer climate in tropic than in extra-tropic area, and higher predictabilities over ocean than over land for the fields of precipitation, sea level pressure and surface air temperature; for 500 hPa geopotential height field, the predictability assuming a zonal distribution decreases from tropic to middle-high latitudes, and in China it is the highest among those of all fields. Correlation analysis shows that the prediction ability of IAP annual prediction system to summer temperature is higher than that to precipitation, and the prediction skill can be remarkably improved by the correction system. Furthermore, the comparison between annual and extraseasonal hindcasts indicates that precipitation hindcasted extraseasonally is better than that done annually, and the major discrepancy exists in middle-high latitudes.

  16. Numerical Model Predictions of Intrinsically Generated Fluvial Terraces and Comparison to Climate-Change Expectations

    Science.gov (United States)

    Limaye, A. B. S.; Lamb, M. P.

    2014-12-01

    Terraces eroded into sediment (cut-fill) and bedrock (strath) preserve a geomorphic record of river activity. River terraces are often thought to form when a river switches from a period of low vertical incision rates and valley widening to high vertical incision rates and terrace abandonment. Consequently, terraces are frequently interpreted to reflect landscape response to changing external drivers, including tectonics, sea-level, and most commonly, climate. In contrast, unsteady lateral migration in meandering rivers may generate river terraces even under constant vertical incision and without changes in external forcing. To explore this latter mechanism, we use a numerical model and an automated terrace detection algorithm to simulate landscape evolution by a vertically incising, meandering river and isolate the age and geometric fingerprints of intrinsically generated river terraces. Simulations indicate that terraces form for a wide range of lateral and vertical incision rates, and the time interval between unique terrace levels is limited by a characteristic timescale for relief generation. Surprisingly, intrinsically generated terraces are commonly paired, an attribute that is thought to be diagnostic of climate change. For low ratios of vertical-to-lateral erosion rates, modeled terraces are longitudinally extensive and typically dip toward the valley center, and terrace slope is proportional to the ratio of vertical to lateral erosion. Evolving, spatial differences in bank strength between bedrock and sediment reduce terrace formation frequency and length, and can explain sub-linear terrace margins at valley boundaries. Comparison of model predictions to natural river terraces indicates that terrace length is the most reliable indicator of terrace formation by pulses of vertical incision, and may contain the imprint of past climate change on landscapes.

  17. Building world narratives for climate change impact, adaptation and vulnerability analyses

    OpenAIRE

    Hallegatte, Stéphane; Valentin, Przyluski; Vogt-Schilb, Adrien

    2011-01-01

    International audience The impacts of climate change on human systems depend not only on the level of emissions but also on how inherently vulnerable these systems are to the changing climate. The large uncertainties over future development and structure of societies and economies mean that the assessment of climate change efects is complex. One way to deal with this complexity is by using scenario analysis that takes account of these socio-economic diferences. The challenge is to identify...

  18. Numerical investigation of climate factors impact on carbon cycle in the East Asian terrestrial ecosystem

    Energy Technology Data Exchange (ETDEWEB)

    Mabuchi, K. [Meteorological Research Institute, Tsukuba (Japan); Takahashi, K. [Japan Meteorological Agency, Tokyo (Japan); Nasahara, K.N. [Univ. of Tsukuba (Japan). Inst. of Agricultural and Forest Engineering

    2009-07-01

    The present state of environmental problems due to global warming resulting from increases of greenhouse gases has reached new levels. The international treaty known as the United Nations Framework Convention on Climate Change (UNFCCC) was adopted in 1992 to begin to consider what can be done to reduce global warming. The Kyoto Protocol, adopted in 1997 at the third Conference of the Parties to the UNFCCC (COP 3), proposed a worldwide reduction of greenhouse gas emission. Under these conditions, it became necessary to monitor the increases of greenhouse gases, especially carbon dioxide, and to conduct research to further understand the mechanisms of interactions between environmental changes and the carbon balance. Estimations of the carbon dioxide budget are of great importance in taking the proper steps to deal with increased concentrations due to anthropogenic emissions, and in predictions of future concentration levels. The main components of the carbon dioxide budget are anthropogenic emissions, atmospheric concentration, the exchange between the atmosphere and ocean, and the exchange between the atmosphere and terrestrial ecosystems. Among these components, the role of the terrestrial ecosystem is still uncertain, due to the heterogeneity of that system. Using a regional climate model that includes a terrestrial biosphere model, numerical simulations were performed to clarify the mechanism of the carbon cycle between the terrestrial ecosystem and the atmosphere and to investigate the climate factors impact on the carbon cycle in the East Asian terrestrial ecosystem. Model verifications were performed with regard to the principal elements: precipitation and vegetation phenology. The variations of the atmospheric carbon dioxide concentration simulated by the model were validated using the data at six in situ observatories. After the confirmations of the model performance, regional features of the impact of climate factors on the gross primary production (GPP

  19. A novel approach for modelling vegetation distributions and analysing vegetation sensitivity through trait-climate relationships in China

    Science.gov (United States)

    Yang, Yanzheng; Zhu, Qiuan; Peng, Changhui; Wang, Han; Xue, Wei; Lin, Guanghui; Wen, Zhongming; Chang, Jie; Wang, Meng; Liu, Guobin; Li, Shiqing

    2016-04-01

    Increasing evidence indicates that current dynamic global vegetation models (DGVMs) have suffered from insufficient realism and are difficult to improve, particularly because they are built on plant functional type (PFT) schemes. Therefore, new approaches, such as plant trait-based methods, are urgently needed to replace PFT schemes when predicting the distribution of vegetation and investigating vegetation sensitivity. As an important direction towards constructing next-generation DGVMs based on plant functional traits, we propose a novel approach for modelling vegetation distributions and analysing vegetation sensitivity through trait-climate relationships in China. The results demonstrated that a Gaussian mixture model (GMM) trained with a LMA-Nmass-LAI data combination yielded an accuracy of 72.82% in simulating vegetation distribution, providing more detailed parameter information regarding community structures and ecosystem functions. The new approach also performed well in analyses of vegetation sensitivity to different climatic scenarios. Although the trait-climate relationship is not the only candidate useful for predicting vegetation distributions and analysing climatic sensitivity, it sheds new light on the development of next-generation trait-based DGVMs.

  20. Meta-analyses of the determinants and outcomes of belief in climate change

    Science.gov (United States)

    Hornsey, Matthew J.; Harris, Emily A.; Bain, Paul G.; Fielding, Kelly S.

    2016-06-01

    Recent growth in the number of studies examining belief in climate change is a positive development, but presents an ironic challenge in that it can be difficult for academics, practitioners and policy makers to keep pace. As a response to this challenge, we report on a meta-analysis of the correlates of belief in climate change. Twenty-seven variables were examined by synthesizing 25 polls and 171 academic studies across 56 nations. Two broad conclusions emerged. First, many intuitively appealing variables (such as education, sex, subjective knowledge, and experience of extreme weather events) were overshadowed in predictive power by values, ideologies, worldviews and political orientation. Second, climate change beliefs have only a small to moderate effect on the extent to which people are willing to act in climate-friendly ways. Implications for converting sceptics to the climate change cause--and for converting believers’ intentions into action--are discussed.

  1. A new numerical framework for simulating the control of weather and climate on the evolution of soil-mantled hillslopes

    Science.gov (United States)

    Bovy, Benoît; Braun, Jean; Demoulin, Alain

    2016-06-01

    We present a new numerical framework for simulating short to long-term hillslope evolution. This modeling framework, to which we have given the name CLICHE (CLImate Control on Hillslope Evolution), aims to better capture the control of climate on soil dynamics. It allows the use of realistic forcing that involves, through a specific time discretization scheme, the variability of both the temperature and precipitation at time scales ranging from the daily rainfall events to the climatic oscillations of the Quaternary, also including seasonal variability. Two simple models of soil temperature and soil water balance permit the link between the climatic inputs and derived quantities that take part in the computation of the soil flux, such as the surface water discharge and the depth of the non-frozen soil layer. Using this framework together with a multi-process parameterization of soil transport, we apply an original method to calculate hillslope effective diffusivity as a function of climate. This allows us to demonstrate the ability of the model to simulate observed rates of hillslope erosion under different climates (cold and temperate) with a single set of parameter values. Numerical experiments furthermore suggest a potential high peak of sediment transport on hillslopes during the glacial-interglacial transitions of the Quaternary. We finally discuss the need to improve the parameterization of the soil production and transport processes in order to explicitly account for other key controlling factors that are also climate-sensitive, such as biological activity.

  2. Application of Microneedle Arrays for Enhancement of Transdermal Permeation of Insulin: In Vitro Experiments, Scaling Analyses and Numerical Simulations.

    Science.gov (United States)

    Leeladurga, V; Teja, U Chandra; Sultana, S K Ashraf; Sudeep, K; Anusha, V Sai Sri; Han, Tao; Nalluri, Buchi N; Das, Diganta B

    2016-08-01

    The aim of this investigation is to study the effect of donor concentration and microneedle (MN) length on permeation of insulin and further evaluating the data using scaling analyses and numerical simulations. Histological evaluation of skin sections was carried to evaluate the skin disruption and depth of penetration by MNs. Scaling analyses were done using dimensionless parameters like concentration of drug (C t/C s), thickness (h/L) and surface area of the skin (S a/L (2)). Simulation studies were carried out using MATLAB and COMSOL software to simulate the insulin permeation using histological sections of MN-treated skin and experimental parameters like passive diffusion coefficient. A 1.6-fold increase in transdermal flux and 1.9-fold decrease in lag time values were observed with 1.5 mm MN when compared with passive studies. Good correlation (R (2) > 0.99) was observed between different parameters using scaling analyses. Also, the in vitro and simulated permeations profiles were found to be similar (f 2 ≥ 50). Insulin permeation significantly increased with increase in donor concentration and MN length (p insulin with new dimensions of MN in optimizing insulin delivery. Overall, it can be inferred that the application of MNs can significantly enhance insulin permeation and may be an efficient alternative for injectable insulin therapy in humans. PMID:26729523

  3. A numerical model of continental topographic evolution integrating thin sheet tectonics, river transport, and climate

    Science.gov (United States)

    Garcia-Castellanos, D.; Jimenez-Munt, I.

    2013-12-01

    How much does the erosion and sedimentation at the crust's surface influence on the patterns and distribution of tectonic deformation? This question has been mostly addressed from a numerical modelling perspective, at scales ranging from local to orogenic. Here we present a model that aims at constraining this phenomenon at the continental scale. With this purpose, we couple a thin-sheet viscous model of continental deformation with a stream-power surface transport model. The model also incorporates flexural isostatic compensation that permits the formation of large sedimentary foreland basins and a precipitation model that reproduces basic climatic effects such as continentality and orographic rainfall and rain shadow. We quantify the feedbacks between these 4 processes in a synthetic scenario inspired by the India-Asia collision. The model reproduces first-order characteristics of the growth of the Tibetan Plateau as a result of the Indian indentation. A large intramountain basin (comparable to the Tarim Basin) develops when predefining a hard inherited area in the undeformed foreland (Asia). The amount of sediment trapped in it is very sensitive to climatic parameters, particularly to evaporation, because it crucially determines its endorheic/exorheic drainage. We identify some degree of feedback between the deep and the surface processes occurs, leading locally to a <20% increase in deformation rates if orographic precipitation is account for (relative to a reference model with evenly-distributed precipitation). These enhanced thickening of the crust takes place particularly in areas of concentrated precipitation and steep slope, i.e., at the upwind flank of the growing plateau. This effect is particularly enhanced at the corners of the indenter (syntaxes). We hypothesize that this may provide clues for better understanding the mechanisms underlying the intriguing tectonic aneurisms documented in the syntaxes of the Himalayas.

  4. Analysing the Scalability of Climate Codes Using New Features of Scalasca

    OpenAIRE

    Harlacher, M.; Calotoiu, A.; Dennis, J; de Wolf, F

    2016-01-01

    This paper shows how recently developed features of the performance analysis tool Scalasca helped gain important insights into the performance behaviour of state-of-the-art climate codes in the CESM (Community Earth System Model) ensemble. Particular emphasis is given to the load balance of the sea-ice model and the scaling behaviour of the atmospheric model. The presented work is a result of the project Enabling Climate Simulation at Extreme Scale, which has been funded through the G8 Resear...

  5. Alluvial fan response to climatic change: Insights from numerical modeling (Invited)

    Science.gov (United States)

    Pelletier, J. D.

    2009-12-01

    Alluvial fans in the western U.S. exhibit a regionally correlative sequence of Plio-Quaternary deposits. Cosmogenic and U-series dating has greatly improved the age control on these deposits and their associated terraces and generally strengthened the case for aggradation during humid-to-arid transitions. Still, the linkages between climate change, upland basin response, and alluvial fan response are not well constrained. Fans may fill and cut as a result of autogenetic processes/internal adjustments, changes in regional temperature (which controls snowmelt-induced flooding), changes in the frequency-size distribution of rainfall events, and/or changes in upslope vegetation. Here I describe the results of a numerical modeling study designed to better constrain the relationships between different end-member forcing mechanisms and the geologic record of alluvial fan deposits and terraces. The model solves the evolution of the fan topography using Exner's equation (conservation of mass) coupled with a nonlinear, threshold-controlled transport relation for sand and gravel. Bank retreat is modeled using an advection equation with a rate proportional to bank shear stress. I begin by considering the building of a fan under conditions of constant water and sediment supply. This simple system exhibits all of the complexity of fans developed under experimental conditions, and it provides insights into the mechanisms that control avulsions and it provides a baseline estimate for the within-fan relief that can result from autogenetic processes. Relationships between the magnitude and period of variations in the sediment-to-water ratio and the geomorphic response of fans are then discussed. I also consider the response of a coupled drainage basin-fan system to changes in climate, including the hydrologic and vegetation response of upland hillslopes. Fans can aggrade or incise in response to the same climatic event depending on the relief of the upstream drainage basin, which

  6. A numerical investigation on exergy analyses of a pyroelectric tryglycine sulfate (TGS)-based solar energy harvesting system

    Science.gov (United States)

    Sharma, Manish; Vaish, Rahul; Singh Chauhan, Vishal

    2016-02-01

    This study is based on a numerical demonstration of energy and exergy analyses of a solar energy harvesting system based on the pyroelectric effect. The performance of a tryglycine sulfate (TGS) single crystal was investigated mathematically in the present study. The power output was optimized for different load resistances and load capacitances. The maximum power output was obtained as 0.95 μW across a load resistance of 40 MΩ and a 4.7 μF load capacitor. Further exergy analysis was performed for a pyroelectric energy harvesting system. Maximum values for electrical and thermal exergies obtained are 0.12 μW and 12 mW, respectively. Furthermore the maximum obtained electrical and thermal exergy efficiencies are 0.000 037% and 3.6%, respectively. The average thermal exergy efficiency is 2.15% for a cycle frequency of 0.014 Hz.

  7. Numerical analyses of the electromagnetic force acting on high-temperature superconducting power cables due to fault current

    International Nuclear Information System (INIS)

    In Japan, the development of the 66 kV class REB2C3O7−x (RE123; RE stands for rare earth) high-temperature superconducting (HTS) power cable was begun in 2008 as a national project. 66 kV class RE123 HTS power cables may be subjected to a fault current of 31.5 kArms for 2 s. Therefore, the electromagnetic and thermal characteristics of HTS power cables have to be determined under fault conditions to ensure stability and feasibility. In this study, numerical analyses were performed using a computer program on the basis of the finite element method and an equivalent circuit model to evaluate the electromagnetic and thermal behaviors of a 66 kV class HTS model cable resulting from the fault current. The electromagnetic forces acting on coated conductors that are assembled in the HTS model cable were also numerically simulated under the fault condition. The result found was that the maximum electromagnetic force acting on the coated conductor in the peeling and compression direction was less than 20 kPa. However, the irreversible Ic degradations caused by the peeling and compression stress were above several MPa in previous studies. Thus, the results of this study indicate a low probability of Ic degradation of the 66 kV class HTS power cable being caused by the electromagnetic force due to the fault current. (paper)

  8. Predictability of Regional Climate: A Bayesian Approach to Analysing a WRF Model Ensemble

    Science.gov (United States)

    Bruyere, C. L.; Mesquita, M. D. S.; Paimazumder, D.

    2013-12-01

    This study investigates aspects of climate predictability with a focus on climatic variables and different characteristics of extremes over nine North American climatic regions and two selected Atlantic sectors. An ensemble of state-of-the-art Weather Research and Forecasting Model (WRF) simulations is used for the analysis. The ensemble is comprised of a combination of various physics schemes, initial conditions, domain sizes, boundary conditions and breeding techniques. The main objectives of this research are: 1) to increase our understanding of the ability of WRF to capture regional climate information - both at the individual and collective ensemble members, 2) to investigate the role of different members and their synergy in reproducing regional climate 3) to estimate the associated uncertainty. In this study, we propose a Bayesian framework to study the predictability of extremes and associated uncertainties in order to provide a wealth of knowledge about WRF reliability and provide further clarity and understanding of the sensitivities and optimal combinations. The choice of the Bayesian model, as opposed to standard methods, is made because: a) this method has a mean square error that is less than standard statistics, which makes it a more robust method; b) it allows for the use of small sample sizes, which are typical in high-resolution modeling; c) it provides a probabilistic view of uncertainty, which is useful when making decisions concerning ensemble members.

  9. A new hierarchical Bayesian approach to analyse environmental and climatic influences on debris flow occurrence

    Science.gov (United States)

    Jomelli, Vincent; Pavlova, Irina; Eckert, Nicolas; Grancher, Delphine; Brunstein, Daniel

    2015-12-01

    How can debris flow occurrences be modelled at regional scale and take both environmental and climatic conditions into account? And, of the two, which has the most influence on debris flow activity? In this paper, we try to answer these questions with an innovative Bayesian hierarchical probabilistic model that simultaneously accounts for how debris flows respond to environmental and climatic variables. In it, full decomposition of space and time effects in occurrence probabilities is assumed, revealing an environmental and a climatic trend shared by all years/catchments, respectively, clearly distinguished from residual "random" effects. The resulting regional and annual occurrence probabilities evaluated as functions of the covariates make it possible to weight the respective contribution of the different terms and, more generally, to check the model performances at different spatio-temporal scales. After suitable validation, the model can be used to make predictions at undocumented sites and could be used in further studies for predictions under future climate conditions. Also, the Bayesian paradigm easily copes with missing data, thus making it possible to account for events that may have been missed during surveys. As a case study, we extract 124 debris flow event triggered between 1970 and 2005 in 27 catchments located in the French Alps from the French national natural hazard survey and model their variability of occurrence considering environmental and climatic predictors at the same time. We document the environmental characteristics of each debris flow catchment (morphometry, lithology, land cover, and the presence of permafrost). We also compute 15 climate variables including mean temperature and precipitation between May and October and the number of rainy days with daily cumulative rainfall greater than 10/15/20/25/30/40 mm day- 1. Application of our model shows that the combination of environmental and climatic predictors explained 77% of the overall

  10. Final Progress Report: Collaborative Research: Decadal-to-Centennial Climate & Climate Change Studies with Enhanced Variable and Uniform Resolution GCMs Using Advanced Numerical Techniques

    Energy Technology Data Exchange (ETDEWEB)

    Fox-Rabinovitz, M; Cote, J

    2009-06-05

    The joint U.S-Canadian project has been devoted to: (a) decadal climate studies using developed state-of-the-art GCMs (General Circulation Models) with enhanced variable and uniform resolution; (b) development and implementation of advanced numerical techniques; (c) research in parallel computing and associated numerical methods; (d) atmospheric chemistry experiments related to climate issues; (e) validation of regional climate modeling strategies for nested- and stretched-grid models. The variable-resolution stretched-grid (SG) GCMs produce accurate and cost-efficient regional climate simulations with mesoscale resolution. The advantage of the stretched grid approach is that it allows us to preserve the high quality of both global and regional circulations while providing consistent interactions between global and regional scales and phenomena. The major accomplishment for the project has been the successful international SGMIP-1 and SGMIP-2 (Stretched-Grid Model Intercomparison Project, phase-1 and phase-2) based on this research developments and activities. The SGMIP provides unique high-resolution regional and global multi-model ensembles beneficial for regional climate modeling and broader modeling community. The U.S SGMIP simulations have been produced using SciDAC ORNL supercomputers. Collaborations with other international participants M. Deque (Meteo-France) and J. McGregor (CSIRO, Australia) and their centers and groups have been beneficial for the strong joint effort, especially for the SGMIP activities. The WMO/WCRP/WGNE endorsed the SGMIP activities in 2004-2008. This project reflects a trend in the modeling and broader communities to move towards regional and sub-regional assessments and applications important for the U.S. and Canadian public, business and policy decision makers, as well as for international collaborations on regional, and especially climate related issues.

  11. Impact of climate change on the distribution of Aedes albopictus (Diptera: Culicidae) in northern Japan: retrospective analyses.

    Science.gov (United States)

    Mogi, Motoyoshi; Tuno, Nobuko

    2014-05-01

    The impact of climate change on the distribution of Aedes albopictus (Skuse) was analyzed in northern Japan, where chronological distribution records are incomplete. We analyzed local climate data using linear regression of the thermal suitability index (TSI) for the mosquito and mean annual temperature as functions of time. In northern Japan, thermal conditions since the early 20th century have become increasingly suitable for Ae. albopictus, more as a result of decreasing coldness in the overwintering season than increasing warmth in the reproductive season. Based on recent discovery records of Ae. albopictus in the northern border range, we determined thermal criteria for estimating when its persistent establishment became thermally possible. Retrospective analyses indicated that those criteria were reached in most coastal lowlands of northern Honshu before the accelerated temperature increase after the mid-1980s and the first records of this species after 1990; at some sites, temperature criteria were reached during or before the early 20th century. Expansion of the thermally suitable range after 1990 was supported only for inland areas and the northernmost Pacific coast. The estimated expansion rate was approximately 26 km per decade. Our analyses also demonstrated the importance of local climate heterogeneity (apart from north-south or altitudinal temperature gradients) in determining the expansion pattern. PMID:24897849

  12. A numerical modelling tool for assessing the impact of climate change and management options on water supply systems

    Science.gov (United States)

    Romano, Emanuele; Guyennon, Nicolas; Mariani, Davide; Bruna Petrangeli, Anna; Portoghese, Ivan

    2014-05-01

    Conditions of scarcity for a water supply system occur when the available resource are not able to satisfy the connected demands. They can arise both from a decreasing of the inflow to the exploited resources and/or from a increasing of the demand. Such conditions can be assessed by a water balance model able to simulate both the hydrological processes describing the relationships between the meteorological forcing (precipitation) and the inflows to the exploited reservoir, and the intra- and inter-annual time distribution of the connected demand and the reservoir management policies. We present a numerical modelling tool, developed for the management of the Maggiore Lake, that computes at daily scale the water budget of such reservoir taking into account 1) the monthly precipitation over the watershed basin and the related inflow; 2) the seasonal demand for irrigation and 3) the operative hydrometric levels constraints to the lake water withdrawal. The model represents precipitation over the basin through the space mean of the standardized precipitation indices computed at different aggregation scales using observed time series. The relationship between the precipitation regime and the inflow to the reservoir is obtained through a simple multilinear regression model, considering the SPI computed at 1, 3 and 6 months as independent variables: this allows to take hydrological processes into account featuring different characteristic times and to simulate both the historic inflow regime and the possible conditions forecast by climate scenarios. The regression model is validated on the precipitation and lake inflow observations in the period 1996-2013 using a leave-one-out cross validation. The seasonal irrigation demand is assigned based on the extensions of crops fed by the lake water and regardless of the climate conditions; the actual supply is limited by the operative hydrometric range of allowable water levels, which stop water distribution when the lake level

  13. Energetic and exergetic analyses of carbon dioxide transcritical refrigeration systems for hot climates

    Directory of Open Access Journals (Sweden)

    Fazelpour Farivar

    2015-01-01

    Full Text Available In the last two decades many scientific papers and reports have been published in the field of the application of the carbon dioxide as a refrigerant for refrigeration systems and heat pumps. Special attention has been paid to the transcritical cycle. However, almost no papers discussed such cycles for hot climates, i.e., when the temperature of the environment is higher than 40ºС during a long period of time. This paper deals with the energetic and exergetic evaluation of a CO2 refrigeration system operating in a transcritical cycle under hot climatic conditions. The performance and exergy efficiency of the CO2 refrigeration system depend on the operation conditions. The effect of varying these conditions is also investigated as well as the limitations associated with these conditions.

  14. Late Holocene climatic changes in Tierra del Fuego based on multiproxy analyses of peat deposits

    OpenAIRE

    Mauquoy, D.; Blaauw, Maarten; van Geel, B; Borromei, A.; M. Quattrocchio; Chambers, F.M.; Possnert, G.

    2004-01-01

    A ca. 1400-yr record from a raised bog in Isla Grande, Tierra del Fuego, Argentina, registers climate fluctuations, including a Medieval Warm Period, although evidence for the 'Little Ice Age' is less clear. Changes in temperature and/or precipitation were inferred from plant macrofossils, pollen, fungal spores, testate amebae, and peat humification. The chronology was established using a C-14 wiggle-matching technique that provides improved age control for at least part of the record compare...

  15. Energetic and exergetic analyses of carbon dioxide transcritical refrigeration systems for hot climates

    OpenAIRE

    Fazelpour Farivar

    2015-01-01

    In the last two decades many scientific papers and reports have been published in the field of the application of the carbon dioxide as a refrigerant for refrigeration systems and heat pumps. Special attention has been paid to the transcritical cycle. However, almost no papers discussed such cycles for hot climates, i.e., when the temperature of the environment is higher than 40ºС during a long period of time. This paper deals with the energetic and exerget...

  16. Recent Regional Climate State and Change - Derived through Downscaling Homogeneous Large-scale Components of Re-analyses

    Science.gov (United States)

    Von Storch, H.; Klehmet, K.; Geyer, B.; Li, D.; Schubert-Frisius, M.; Tim, N.; Zorita, E.

    2015-12-01

    Global re-analyses suffer from inhomogeneities, as they process data from networks under development. However, the large-scale component of such re-analyses is mostly homogeneous; additional observational data add in most cases to a better description of regional details and less so on large-scale states. Therefore, the concept of downscaling may be applied to homogeneously complementing the large-scale state of the re-analyses with regional detail - wherever the condition of homogeneity of the large-scales is fulfilled. Technically this can be done by using a regional climate model, or a global climate model, which is constrained on the large scale by spectral nudging. This approach has been developed and tested for the region of Europe, and a skillful representation of regional risks - in particular marine risks - was identified. While the data density in Europe is considerably better than in most other regions of the world, even here insufficient spatial and temporal coverage is limiting risk assessments. Therefore, downscaled data-sets are frequently used by off-shore industries. We have run this system also in regions with reduced or absent data coverage, such as the Lena catchment in Siberia, in the Yellow Sea/Bo Hai region in East Asia, in Namibia and the adjacent Atlantic Ocean. Also a global (large scale constrained) simulation has been. It turns out that spatially detailed reconstruction of the state and change of climate in the three to six decades is doable for any region of the world.The different data sets are archived and may freely by used for scientific purposes. Of course, before application, a careful analysis of the quality for the intended application is needed, as sometimes unexpected changes in the quality of the description of large-scale driving states prevail.

  17. Southern African continental climate since the late Pleistocene: Insights from biomarker analyses of Kalahari salt pan sediments

    Science.gov (United States)

    Belz, Lukas; Schüller, Irka; Wehrmann, Achim; Wilkes, Heinz

    2016-04-01

    The climate system of sub-tropical southern Africa is mainly controlled by large scale atmospheric and marine circulation processes and, therefore, very sensitive to global climate change. This underlines the importance of paleoenvironmental reconstructions in order to estimate regional implications of current global changes. However, the majority of studies on southern African paleoclimate are based on the investigation of marine sedimentary archives and past climate development especially in continental areas is still poorly understood. This emphasizes the necessity of continental proxy-data from this area. Proxy datasets from local geoarchives especially of the southwestern Kalahari region are still scarce. A main problem is the absence of conventional continental climatic archives, due to the lack of lacustrine systems. In this study we are exploring the utility of sediments from western Kalahari salt pans, i.e. local depressions which are flooded temporarily during rainfall events. An age model based on 14C dating of total organic carbon (TOC) shows evidence that sedimentation predominates over erosional processes with respect to pan formation. Besides the analyses of basic geochemical bulk parameters including TOC, δ13CTOC, total inorganic carbon, δ13CTIC, δ18OTIC, total nitrogen and δ15N, our paleo-climatic approach focuses on reconstruction of local vegetation assemblages to identify changes in the ecosystem. This is pursued using plant biomarkers, particularly leaf wax n-alkanes and n-alcohols and their stable carbon and hydrogen isotopic signatures. Results show prominent shifts in n-alkane and n-alkanol distributions and compound specific carbon isotope values, pointing to changes to a more grass dominated environment during Heinrich Stadial 1 (18.5-14.6 ka BP), while hydrogen isotope values suggest wetter phases during Holocene and LGM. This high variability indicates the local vulnerability to global change.

  18. The climate change law of the federal government. Analyses and proposals to its further development; Das Klimaschutzrecht des Bundes. Analyse und Vorschlaege zu seiner Weiterentwicklung

    Energy Technology Data Exchange (ETDEWEB)

    Sina, Stephan; Garstetter, Christiane; Bausch, Camilla; Goerlach, Benjamin; Neubauer, Alexander [Ecologic gGmbH Institut fuer Internationale und Europaeische Umweltpolitik, Berlin (Germany); Rodi, Michael [Greifswald Univ. (Germany). Lehrstuhl fuer oeffentliches Recht, Finanz- und Steuerrecht

    2011-09-15

    The present report provides an analysis of the current German federal climate change law. Due to the crosssectoral character of this law, the study comprises regulations from different sectors and areas of law such as emissions trading, the energy sector and agriculture. Based on this analysis, proposals for the advancement of the German federal law of climate change are developed in five particular areas: a potential outline for a general climate protection act serving as the central legal act for climate change law, further considerations on the structure of climate change law, development proposals related to energy grids, federal requirements for municipal climate protection as well as agricultural land use. (orig.)

  19. The effect of climate forcing on numerical simulations of the Cordilleran ice sheet at the Last Glacial Maximum

    OpenAIRE

    Seguinot, J.; C. Khroulev; I. Rogozhina; A. P. Stroeven; Q. Zhang

    2013-01-01

    We present an ensemble of numerical simulations of the Cordilleran ice sheet during the Last Glacial Maximum performed with the Parallel Ice Sheet Model (PISM), applying temperature offsets to the present-day climatologies from five different datasets. Monthly mean surface air temperature and precipitation from WorldClim, the NCEP/NCAR reanalysis, the ERA-Interim reanalysis, the Climate Forecast System Reanalysis and the North American Regional Reanalysis ar...

  20. The effect of climate forcing on numerical simulations of the Cordilleran ice sheet at the Last Glacial Maximum

    OpenAIRE

    Seguinot, J.; C. Khroulev; I. Rogozhina; A. P. Stroeven; Q. Zhang

    2014-01-01

    We present an ensemble of numerical simulations of the Cordilleran ice sheet during the Last Glacial Maximum performed with the Parallel Ice Sheet Model (PISM), applying temperature offsets to the present-day climatologies from five different data sets. Monthly mean surface air temperature and precipitation from WorldClim, the NCEP/NCAR reanalysis, the ERA-Interim reanalysis, the Climate Forecast System Reanalysis and the North American Regional Reanalysis are used to compute surface mass bal...

  1. ICLEA - The Virtual Institute of Integrated Climate and Landscape Evolution Analyses

    Science.gov (United States)

    Schwab, Markus J.; Brauer, Achim; Błaszkiewicz, Mirosław; Blume, Theresa; Itzerott, Sibylle; Raab, Thomas; Wilmking, Martin; Iclea Team

    2016-04-01

    In the Virtual Institute ICLEA we view on past changes as natural experiments as a guidebook for better anticipation of future changes and their impacts. Since the natural evolution became increasingly superimposed by human impacts since the Neolithic we include an in-depth discussion of impacts of climate and environment change on societies and vice versa. The partner focusing their research capacities and expertise in ICLEA and offers young researchers an interdisciplinary and structured education and promote their early independence through coaching and mentoring. Training, Research and Analytical workshops between research partners of ICLEA are an important measure to qualify young researchers. Understanding causes and effects of present-day climate change on landscapes and the human habitat faces two main challenges, (I) too short time series of instrumental observation that do not cover the full range of variability since mechanisms of climate change and landscape evolution work on different time scales, which often not susceptible to human perception, and, (II) distinct regional differences due to the location with respect to oceanic/continental climatic influences, the geological underground, and the history and intensity of anthropogenic land-use. Both challenges are central for the ICLEA research strategy and demand a high degree of interdisciplinary. In particular, the need to link observations and measurements of ongoing changes with information from the past taken from natural archives requires joint work of scientists with very different time perspectives. On the one hand, scientists that work at geological time scales of thousands and more years and, on the other hand, those observing and investigating recent processes at short time scales. The long-term mission of the Virtual Institute is to provide a substantiated data basis for sustained environmental maintenance based on a profound process understanding at all relevant time scales. Aim is to

  2. Analysing present, past and future tropical cyclone activity as inferred from an ensemble of Coupled Global Climate Models

    OpenAIRE

    Caron, Louis-Philippe; Jones, Colin G.

    2008-01-01

    Using the Yearly Genesis Parameter (YGP) and the Convective-YGP (CYGP), the main large-scale climatic fields controlling tropical cyclone (TC) formation are analysed and used to infer the number of TCs in a given basin using ERA40 reanalyses for the period 1983–2002. Both indices show a reasonable global number and spatial distribution of implied TCs compared to observations. Using the same approach, we evaluate TC activity in the last 20-yr period of the 20th century in an ensemble of nine C...

  3. Analyses of Observed and Anticipated Changes in Extreme Climate Events in the Northwest Himalaya

    Directory of Open Access Journals (Sweden)

    Dharmaveer Singh

    2016-02-01

    Full Text Available In this study, past (1970-2005 as well as future long term (2011-2099 trends in various extreme events of temperature and precipitation have been investigated over selected hydro-meteorological stations in the Sutlej river basin. The ensembles of two Coupled Model Intercomparison Project (CMIP3 models: third generation Canadian Coupled Global Climate Model and Hadley Centre Coupled Model have been used for simulation of future daily time series of temperature (maximum and minimum and precipitation under A2 emission scenario. Large scale atmospheric variables of both models and National Centre for Environmental Prediction/National Centre for Atmospheric Research reanalysis data sets have been downscaled using statistical downscaling technique at individual stations. A total number of 25 extreme indices of temperature (14 and precipitation (11 as specified by the Expert Team of the World Meteorological Organization and Climate Variability and Predictability are derived for the past and future periods. Trends in extreme indices are detected over time using the modified Mann-Kendall test method. The stations which have shown either decrease or no change in hot extreme events (i.e., maximum TMax, warm days, warm nights, maximum TMin, tropical nights, summer days and warm spell duration indicators for 1970–2005 and increase in cold extreme events (cool days, cool nights, frost days and cold spell duration indicators are predicted to increase and decrease respectively in the future. In addition, an increase in frequency and intensity of extreme precipitation events is also predicted.

  4. Analysing present, past and future tropical cyclone activity as inferred from an ensemble of Coupled Global Climate Models

    Energy Technology Data Exchange (ETDEWEB)

    Caron, Louis-Philippe; Jones, Colin G. (Univ. du Quebec, CRCMD Network, Montreal (Canada)). e-mail: lpcaron@sca.uQ_am.ca

    2008-01-15

    Using the Yearly Genesis Parameter (YGP) and the Convective-YGP (CYGP), the main large-scale climatic fields controlling tropical cyclone (TC) formation are analysed and used to infer the number of TCs in a given basin using ERA40 reanalyses for the period 1983-2002. Both indices show a reasonable global number and spatial distribution of implied TCs compared to observations. Using the same approach, we evaluate TC activity in the last 20-yr period of the 20th century in an ensemble of nine Coupled Global Climate Model simulations submitted to the IPCC AR4. We extend this analysis backwards in time, through the 20th century, and find the ensemble derived CYGP suggests no trend in inferred TC numbers while the YGP, after applying a correction to compensate for its oversensitivity to sea surface temperature, suggests a small upward trend. Both indices give a fair geographical distribution of cyclogenesis. Finally, we assess future TC trends using three emission scenarios. Using the CYGP, which appears the most robust index for application to climate change, a small increase is predicted in the northwestern Pacific in the A1B and A2 scenarios

  5. New insights on Arctic Quaternary climate variability from palaeo-records and numerical modelling

    OpenAIRE

    Jakobsson, Martin; Long, A; Ingólfsson, Ó.; Kjaer, K. H.; Spielhagen, R. F.

    2010-01-01

    Terrestrial and marine geological archives in the Arctic contain information on environmental change through Quaternary interglacial–glacial cycles. The Arctic Palaeoclimate and its Extremes (APEX) scientific network aims to better understand the magnitude and frequency of past Arctic climate variability, with focus on the “extreme” versus the “normal” conditions of the climate system. One important motivation for studying the amplitude of past natural environmental changes in the Arctic is t...

  6. Climate change in the Iberian Upwelling System: a numerical study using GCM downscaling

    Science.gov (United States)

    Cordeiro Pires, Ana; Nolasco, Rita; Rocha, Alfredo; Ramos, Alexandre M.; Dubert, Jesus

    2016-07-01

    The present work aims at evaluating the impacts of a climate change scenario on the hydrography and dynamics of the Iberian Upwelling System. Using regional ocean model configurations, the study domain is forced with three different sets of surface fields: a climatological dataset to provide the control run; a dataset obtained from averaging several global climate models (GCM) that integrate the Intergovernmental Panel for Climate Change (IPCC) models used in climate scenarios, for the same period as the climatological dataset; and this same dataset but for a future period, retrieved from the IPCC A2 climate scenario. After ascertaining that the ocean run forced with the GCM dataset for the present compared reasonably well with the climatologically forced run, the results for the future run (relative to the respective present run) show a general temperature increase (from +0.5 to +3 °C) and salinity decrease (from -0.1 to -0.3), particularly in the upper 100-200 m, although these differences depend strongly on season and distance to the coast. There is also strengthening of the SST cross-shore gradient associated to upwelling, which causes narrowing and shallowing of the upwelling jet. This effect is contrary to the meridional wind stress intensification that is also observed, which would tend to strengthen the upwelling jet.

  7. Climate change in the Iberian Upwelling System: a numerical study using GCM downscaling

    Science.gov (United States)

    Cordeiro Pires, Ana; Nolasco, Rita; Rocha, Alfredo; Ramos, Alexandre M.; Dubert, Jesus

    2015-10-01

    The present work aims at evaluating the impacts of a climate change scenario on the hydrography and dynamics of the Iberian Upwelling System. Using regional ocean model configurations, the study domain is forced with three different sets of surface fields: a climatological dataset to provide the control run; a dataset obtained from averaging several global climate models (GCM) that integrate the Intergovernmental Panel for Climate Change (IPCC) models used in climate scenarios, for the same period as the climatological dataset; and this same dataset but for a future period, retrieved from the IPCC A2 climate scenario. After ascertaining that the ocean run forced with the GCM dataset for the present compared reasonably well with the climatologically forced run, the results for the future run (relative to the respective present run) show a general temperature increase (from +0.5 to +3 °C) and salinity decrease (from -0.1 to -0.3), particularly in the upper 100-200 m, although these differences depend strongly on season and distance to the coast. There is also strengthening of the SST cross-shore gradient associated to upwelling, which causes narrowing and shallowing of the upwelling jet. This effect is contrary to the meridional wind stress intensification that is also observed, which would tend to strengthen the upwelling jet.

  8. A NUMERICAL SIMULATION OF THE EFFECT ON CHINESE REGIONAL CLIMATE DUE TO SEASONAL VARIATION OF LAND SURFACE PARAMETERS (PART II)

    Institute of Scientific and Technical Information of China (English)

    孙健; 李维亮; 周秀骥

    2001-01-01

    The effect on climate due to seasonal variation of vegetation and roughness length was simulated in Part I of this essay. In Part II, the individual effect of albedo and the joint effect of all those factors (vegetation, roughness length and albedo) were calculated by numerical sensitivity experiments. The results showed that: (1) There is no significant effect on precipitation if the albedo of 4 seasons is used to replace the CRCM's climate average data, but the effect on land surface temperature can be seen clearly. And the effect also can be seen in adjacent regions. (2) If all these three factors are used to replace the CRCM's climate average data at the same time, the effect on precipitation is significant, the most variation value is 300 mm. And the effect on temperature is similar to what we can see if only one of these factors in CRCM is replaced by monthly or seasonal data. (3) Seasonal variation of land surface parameters has important effect not only on regional climate, but also on global environment.

  9. Numerical modeling of shoreline undulations part 2: Varying wave climate and comparison with observations

    DEFF Research Database (Denmark)

    Kærgaard, Kasper Hauberg; Fredsøe, Jørgen

    2013-01-01

    waves with a directional spreading. In this paper, these findings are extended to firstly include the effect of a varying wave climate on the shoreline morphology and secondly, to tune the model to two naturally occurring shorelines. It is found that the effect of a variable wave climate is to slow down...... the development of the morphology and in some cases to inhibit the formation of shore-parallel spits at the crest of the undulations. On one of the natural shorelines, the west coast of Namibia, the shore is exposed to very obliquely waves from one main direction. Here, the shoreline model is able to...

  10. Self-consistent numerical analyses for scrape-off plasmas and neutral particles in a fer divertor chamber

    International Nuclear Information System (INIS)

    The present report deals with a numerical analysis of characteristics of poloidal divertors in the Fusion Experimental Reactor (abbreviated FER) now under the design study in JAERI. Diverted scrape-off plasmas are formulated and analyzed based on a fluid model including the interaction of the plasma with neutral particles through ionization and charge exchange reactions. The neutral particle behavior is calculated using Monte Carlo methods. The possibility of high density operation of the FER divertor is examined numerically and the pumping requirement for the helium ash exhaust is discussed. It is also shown that the same numerical model gives the results qualitatively consistent with the DIII divertor experiments. (orig.)

  11. How different sources of climate databases influence assessment of growth response in dendroclimatic analyses - case study from Lapland

    Science.gov (United States)

    Sitko, R.; Vido, J.; Škvarenina, J.; Pichler, V.; Scheer, L.; Škvareninová, J.; Nalevanková, P.

    2015-08-01

    The paper deals with the comparison of the time series from different climate databases. We compared the measured data with the modelled data of monthly and seasonal temperature means and precipitation totals. Reliable and as long as possible time series of such data represent the basic starting point of dendroclimatic analyses. We evaluated the differences in the growth response of spruce derived using different databases of the stated climatic characteristics. The stem cores used to derive the cross-correlation function were taken from Hårås locality situated in the boreal zone of the Swedish part of Lapland. We compared the measured records from the nearest meteorological stations situated 18 and 40 km away from the locality with the interpolated values from CRU TS 3.21 climate database and with the reconstructed 502-year-long database. The spatial resolution of the modelled databases was 0.5° × 0.5° of latitude and longitude. We found a systematic error of different magnitudes in the modelled values, and we also quantified a random error and the overall accuracy of the data. The temperature model underestimated the data in comparison with the measured values, while the precipitation model overestimated the data. We also found that the radial increments of spruce correlated more strongly with the temperature than with the precipitation. Hence, in the conditions of the boreal zone, temperature is a more important factor affecting tree-ring formation. We found significantly higher correlations between the radial increment and the modelled precipitation data than with the data measured at the precipitation station situated 18 km from the locality of interest.

  12. NUMERICAL SIMULATION OF INFLUENCE OF INDIAN OCEAN SSTA ON WEATHER AND CLIMATE IN ASIAN MONSOON REGION

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    Sea surface temperature anomaly (SSTA) exerts great influence on the generation of global weather and climate. Much progress has been made with respect to SSTA in the Pacific Ocean region in contrast to the Indian Ocean. The IAP9L model, which is developed at the Institute of Atmospheric Physics of the Chinese Academy of Science, is used to simulate the influence of the Indian Ocean SSTA on the general circulation and weather/climate anomalies in the monsoon region of Asia. It is found that the warm (cool) SSTA in the equatorial low latitudes of the Indian Ocean triggers winter (summer) teleconnection patterns in middle and higher latitudes of the Northern Hemisphere that are similar to PNA or EAP. They play a very important role in the anomaly of circulation or weather and climate in the middle and lower latitudes of the Asian summer monsoon region. With the warm (cool) SSTA forcing in the Indian Ocean, the Asian summer monsoon sets up at a late (early) date and withdraws at a early (late) date, lasting for a short (long) duration at a weak (strong) intensity. The Indian Ocean SSTA is shown to be an indicator for precipitation variation in China.

  13. Statistical analysis of climate variability and anthropogenic climate signals in a global and regional consideration; Statistische Analyse der Klimavariabilitaet und anthropogenen Klimasignale in globaler und regionaler Betrachtung

    Energy Technology Data Exchange (ETDEWEB)

    Schoenwiese, C.D.; Rapp, J.; Walter, A.; Meyhoefer, S.; Denhard, M.

    1998-06-30

    Aim of this project performed in 1994--1997 was the description of observed climate variability on a global, European and German scale and within, the recent 30, 100 and 400 yr period. Furthermore, a causal interpretation in a multiple way was intended. The most important result of observational statistics is the publication (Kluwer, Dordrecht 1997; in English) of the `European Climate Trend Atlas` providing for the 1891--1990 or 1961--1990 periods, respectively, the trends of surface air temperature, precipitation, humidity (1961--1990) and pressure (MSL) for all months and seasons of the year in 316 regionally differentiated trend charts. This is supplemented by a corresponding German Trend Atlas (temperature and precipitation) and a 1961--1990 analysis of temperature and pressure within the troposphere (selected altitudes) and stratosphere. The interpretation, by means of statistical techniques (regression, neural networks), is focussed on the question to which extent trends and interannual variations of temperature may be explained by natural (vulcanism, solar activity, El Nino) or anthropogenic (greenhouse gases, tropospheric sulfate aerosols) forcing. It arises that on a global or hemispheric average the anthropogenic greenhouse effect is already dominating whereas natural forcing - also on a 400 yr mean northern hemisphere scale -- plays a minor role. The spatial signal structures due to anthropogenic forcing found in this statistical way are very similar to those simulated by more sophisticated model computations (GCM). [Deutsch] Ziel des in den Jahren 1994--1997 durchgefuehrten Projektes war es, in den raeumlichen Skalen `global, Europa und Deutschland` sowie den zeitlichen Skalen letzte ca. `30, 100 und 400 Jahre` die beobachtete Klimavariabilitaet zu beschreiben und in multipler Weise ursaechlich zu interpretieren. Das zentrale Ergebnis des deskriptiven Projektteils ist die Publikation (Kluwer, Dordrecht 1997; englisch) eines Europaeischen

  14. Numerical analyses of the effect of SG-interlayer shear stiffness on the structural performance of reinforced glass beams

    DEFF Research Database (Denmark)

    Louter, C.; Nielsen, Jens Henrik

    2013-01-01

    This paper focuses on the numerical modelling of SentryGlas-laminated reinforced glass beams. In these beams, which have been experimentally investigated in preceding research, a stainless steel reinforcement section is laminated at the inner recessed edge of a triple-layer glass beam by means of...

  15. Numerical simulations of a full-scale polymer electrolyte fuel cell with analysing systematic performance in an automotive application

    International Nuclear Information System (INIS)

    Highlights: • A 3-D full-scale fuel cell performance is numerically simulated. • Generated and consumed power in the system is affected by operating condition. • Systematic analysis predicts the net power of conceptual PEFC stack. - Abstract: In fuel cell powered electric vehicles, the net power efficiency is a critical factor in terms of fuel economy and commercialization. Although the fuel cell stack produces enough power to drive the vehicles, the transferred power to the power train could be significantly reduced due to the power consumption to operate the system components of air blower and cooling module. Thus the systematic analysis on the operating condition of the fuel cell stack is essential to predict the net power generation. In this paper numerical simulation is conducted to characterize the fuel cell performance under various operating conditions. Three dimensional and full-scale fuel cell of the active area of 355 cm2 is numerically modelled with 47.3 million grids to capture the complexities of the fluid dynamics, heat transfer and electrochemical reactions. The proposed numerical model requires large computational time and cost, however, it can be powerful to reasonably predict the fuel cell system performance at the early stage of conceptual design without requiring prototypes. Based on the model, it has been shown that the net power is reduced down to 90% of the gross power due to the power consumption of air blower and cooling module

  16. Impact of the closure of Indonesian seaway on climate: A numerical modeling study

    Institute of Scientific and Technical Information of China (English)

    YU Yongqiang; ZHOU Zuyi; ZHANG Xuehong

    2003-01-01

    Using a global OGCM and its relevant coupled ocean-atmosphere GCM with the contemporary, 6 MaBP and 14 MaBP oceanic topography, respectively, a series of numerical experiments are implemented in order to investigate the effect of the north shift of Australian continent on the tropical oceanic circulation, especially the formation of the western Pacific warm pool. The numerical experiments of the individual OGCM forced by the modern atmospheric circulation indicate that the closure of Indonesian passage results in warming in the tropical Pacific Ocean and cooling in the tropical Indian Ocean; furthermore, it also results in change in source of the Indonesian Through Flow (ITF) water, e.g. ITF mainly originates from the south Pacific at 14 MaBP, but it mainly originates from the north Pacific now. The coupled model shows similar results as the individual OGCM qualitatively.

  17. 3-D Numerical Modeling of Heat Transport Phenomena in Soil under Climatic Conditions of Southern Thailand

    Directory of Open Access Journals (Sweden)

    Jompob WAEWSAK

    2014-12-01

    Full Text Available This paper presents a 3-D numerical modeling of heat transport phenomena in soil due to a change of sensible and latent heat, under the ambient conditions of southern Thailand. The vertical soil temperature profile within 3 m was predicted based on energy balance and 3 modes of heat transfer mechanisms, i.e., conduction, convection, and radiation. Mathematical models for estimation of solar radiation intensity, ambient and sky temperatures, relative humidity, and surface wind velocity were used as model inputs. 3-D numerical implicit finite difference schemes, i.e., forward time, and forward, center, and backward spaces were used for discretizing the set of governing, initial, and boundary condition equations. The set of pseudo-linear equations were then solved using the single step Gauss-Seidel iteration method. Computer code was developed by using MATLAB computer software. The soil physical effects; density, thermal conductivity, emissivity, absorptivity, and latent heat on amplitude of soil temperature variation were investigated. Numerical results were validated in comparison to the experimental results. It was found that 3-D numerical modeling could predict the soil temperature to almost the same degree as results that were obtained by experimentation, especially at a depth of 1 m. The root mean square error at ground surface and at depths of 0.5, 1, 1.5, 2, 2.5 and 3 m were 0.169, 0.153, 0.097, 0.116, 0.120, 0.115, and 0.098, respectively. Furthermore, it was found that variation of soil temperature occurred within 0.75 m only.

  18. Numerical model predictions of autogenic fluvial terraces and comparison to climate change expectations

    Science.gov (United States)

    Limaye, Ajay B. S.; Lamb, Michael P.

    2016-03-01

    Terraces eroded into sediment (alluvial) and bedrock (strath) preserve an important history of river activity. River terraces are thought to form when a river switches from a period of slow vertical incision and valley widening to fast vertical incision and terrace abandonment. Consequently, terraces are often interpreted to reflect changing external drivers including tectonics, sea level, and climate. In contrast, the intrinsic unsteadiness of lateral migration in rivers may generate terraces even under constant rates of vertical incision without external forcing. To explore this mechanism, we simulate landscape evolution by a vertically incising, meandering river and isolate the age and geometry of autogenic river terraces. Modeled autogenic terraces form for a wide range of lateral and vertical incision rates and are often paired and longitudinally extensive for intermediate ratios of vertical-to-lateral erosion rate. Autogenic terraces have a characteristic reoccurrence time that scales with the time for relief generation. There is a preservation bias against older terraces due to reworking of previously visited parts of the valley. Evolving, spatial differences in bank strength between bedrock and sediment reduce terrace formation frequency and length, favor pairing, and can explain sublinear terrace margins at valley boundaries. Age differences and geometries for modeled autogenic terraces are consistent, in cases, with natural terraces and overlap with metrics commonly attributed to terrace formation due to climate change. We suggest a new phase space of terrace properties that may allow differentiation of autogenic terraces from terraces formed by external drivers.

  19. Numerical analysis of DNA microarray data of Campylobacter jejuni strains correlated with survival, cytolethal distending toxin and haemolysin analyses

    DEFF Research Database (Denmark)

    On, Stephen L.W.; Dorrell, N.; Petersen, L.;

    2006-01-01

    Molecular epidemiological studies of the enteric pathogen Campylobacter jejuni have suggested that not all animal isolates are equally pathogenic to humans. We examined the use of numerical analysis of whole-genomotype data as a potential tool for evaluating C. jejuni virulence potential. Whole......-genome microarray analysis was used to determine the gene-level complementarity of 12 Danish strains to the pathogenic, genome-sequenced strain NCTC 11168. Cytolethal distending toxin (CDT) and haemolysin activities, and survival characteristics under aerobic conditions at room temperature were also determined....... Among the strains examined, 439 genes were polymorphic. Numerical analysis of these data by use of the squared Euclidean distance coefficient and Ward's clustering method clearly delineated strains into two clusters. CDT and haemolysin activities of cluster 1 strains were not statistically significantly...

  20. Numerical analyses on optimizing a heat pipe thermal management system for lithium-ion batteries during fast charging

    International Nuclear Information System (INIS)

    Thermal management is crucial for the operation of electric vehicles because lithium ion batteries are vulnerable to excessive heat generation during fast charging or other severe scenarios. In this work, an optimized heat pipe thermal management system (HPTMS) is proposed for fast charging lithium ion battery cell/pack. A numerical model is developed and comprehensively validated with experimental results. This model is then employed to investigate the thermal performance of the HPTMS under steady state and transient conditions. It is found that a cylinder vortex generator placed in front of the heat pipe condensers in the coolant stream improves the temperature uniformity. The uses of cooper heat spreaders and cooling fins greatly improve the performance of the thermal management system. Experiments and transient simulations of heat pipe thermal management system integrated with batteries prove that the improved HPTMS is capable for thermal management of batteries during fast charging. The air-cooled HPTMS is infeasible for thermal management of batteries during fast charging at the pack level due to the limitation of low specific heat capacity. - Highlights: • We develop a numerical model for optimizing a heat pipe thermal management system for fast charging batteries. • The numerical model is comprehensively validated with experimental data. • A cylinder vortex generator is placed at the inlet of the cooling stream to improve the temperature uniformity. • We validate the effectiveness of the optimized system with integration of prismatic batteries

  1. GIS-Mapping and Statistical Analyses to Identify Climate-Vulnerable Communities and Populations Exposed to Superfund Sites

    Science.gov (United States)

    Climate change-related cumulative health risks are expected to be disproportionately greater for overburdened communities, due to differential proximity and exposures to chemical sources and flood zones. Communities and populations vulnerable to climate change-associated impacts ...

  2. Creep in Wood Under Variable Climate Conditions: Numerical Modeling and Experimental Validation

    Science.gov (United States)

    Dubois, F.; Randriambololona, H.; Petit, C.

    2005-09-01

    This paper deals with the modeling of linear viscoelastic behavior and strain accumulation (accelerated creep) during moisture content changes in timber. A generalized Kelvin-Voigt model is used and associated in series with a shrinkage-swelling element depending on the mechanical and moisture content states of materials. The hygrothermal aging due to climatic variations implies an evolution of rheological parameters depending upon moisture content and temperature. Two distinct viscoelastic laws, one for drying and the other for moistening, are coupled according to the thermodynamic principles when wood is subjected to nonmonotonous moisture variations. An incremental formulation of behavior is established in the finite element program CAST3M (Software developed by C.E.A. (Commissariat á l'Energi Atomique) and an experimental validation from tension creep-recovery tests is presented.

  3. Gliese 581d Habitable with a CO2-rich atmosphere: Results from Numerical Climate Simulations.

    Science.gov (United States)

    Wordsworth, Robin; Forget, F.; Selsis, F.; Madeleine, J. B.; Millour, E.; Eymet, V.

    2010-10-01

    The exoplanet Gl581d (discovered in 2007) is relatively low mass and near to the outer edge of its system's habitable zone, which has led to much speculation on its possible climate. To help understand the possible conditions on this planet, we have developed a new universal 3D global climate model (GCM). It is derived from the LMD GCMs already used to simulate the Earth, Mars and other terrestrial atmospheres in the solar system, and hence has already been validated over a wide range of physical conditions. We have performed a range of simulations to assess whether, given simple combinations of chemically stable gases (CO2, H2O and N2), Gl581d could sustain liquid water on its surface. Compared to a Sun-like star, the red dwarf Gliese 581 allows higher planetary temperatures, because Rayleigh scattering is reduced. Taking into account the scattering greenhouse effect of both CO2 and H2O clouds, we find that several tens of bars of CO2 are sufficient to maintain global mean temperatures above the melting point of water. As Gl581d is probably in a tidally resonant orbit, condensables such as water and CO2 may be trapped on its dark sides or poles. However, we find that even with conservative assumptions, redistribution of heat by the atmosphere is enough to allow stable conditions with surface liquid water. A dense atmosphere of this kind is quite possible for such a large planet, and could be distinguished from other cases using future observations.

  4. Theoretical analyses and numerical experiments of variational assimilation for one-dimensional ocean temperature model with techniques in inverse problems

    Institute of Scientific and Technical Information of China (English)

    HUANG; Sixun; HAN; Wei; WU; Rongsheng

    2004-01-01

    In the present work, the data assimilation problem in meteorology and physical oceanography is re-examined using the variational optimal control approaches in combination with regularization techniques in inverse problem. Here the estimations of the initial condition,boundary condition and model parameters are performed simultaneously in the framework of variational data assimilation. To overcome the difficulty of ill-posedness, especially for the model parameters distributed in space and time, an additional term is added into the cost functional as a stabilized functional. Numerical experiments show that even with noisy observations the initial conditions and model parameters are recovered to an acceptable degree of accuracy.

  5. Experimental and numerical analyses of pure copper during ECFE process as a novel severe plastic deformation method

    Directory of Open Access Journals (Sweden)

    M. Ebrahimi

    2014-02-01

    Full Text Available In this paper, a new severe plastic deformation method called equal channel forward extrusion (ECFE process has been proposed and investigated by experimental and numerical approaches on the commercial pure copper billets. The experimental results indicated that the magnitudes of yield strength, ultimate tensile strength and Vickers micro-hardness have been markedly improved from 114 MPa, 204 MPa and 68 HV as the annealed condition to 269 MPa, 285 MPa and 126 HV after the fourth pass of ECFE process, respectively. In addition, scanning electron microscopy observation of the samples showed that the average grain size of the as-received state which is about 22 μm has been reduced to 1.4 μm after the final pass. The numerical investigation suggested that although one pass ECFE process fabricates material with the mean effective strain magnitude of about 1, the level of imposed effective plastic strain gradually diminishes from the circumference to the center of the deformed billet.

  6. Numerical Analyses of Bearing Capacity of Deep-Embedded Large-Diameter Cylindrical Structure on Soft Ground Against Lateral Loads

    Institute of Scientific and Technical Information of China (English)

    LUAN Mao-tian; FAN Qing-lai

    2006-01-01

    Presented in this paper is a three-dimensional plastic limit analysis method of bearing capacity of the deeply-embedded large-diameter cylindrical structure in the cross-anisotropic soft ground. The most likely failure mechanism is assumed to be of a composite rupture surface which is composed of an individual wedge in the passive zone or two wedges in both active and passive zones near the mudline, depending on the separation or bonding state at the interface between the cylindrical structure and neighboring soils in the active wedge, and a truncated spherical slip surface at the base of the cylinder when the structure tends to overturn around a point located on the symmetry axis of the structure. The cylindrical structure and soil interaction system under consideration is also numerically analyzed by the finite element method by virtue of the general-purpose FEM software ABAQUS, in which the soil is assumed to obey tie Hill's criterion of yield. Both the failure mechanism assumed and the plastic limit analysis predictions are validated by numerical computations based on FEM. For the K0-consolidated ground of clays typically with anisotropic undrained strength property, it is indicated through a parametric study that limit analysis without consideration of anisotropy of soil overestimates the lateral ultimate bearing capacity of a deeply-embedded cylindrical structure in soft ground in a certain condition.

  7. Safety of existing installations under dynamic loads: observations on nonlinear response of piping systems - experiments, numerical analyses

    International Nuclear Information System (INIS)

    The nonlinear response of piping systems under base excitation or due to pressure waves caused by simulated breaks and valve closure has been investigated experimentally at the HDR reactor. Structural analysis of ruptured piping and the related design of pipe whips restraints are usually performed on the basis of nonlinear material behavior, with powerful computational techniques being used increasingly. Some aspects of these developments (high-level earthquake tests, high-level pressure wave tests, pipe rupture nonlinear analyses) are summarized with implications for qualification and optimal backfitting of operating nuclear power plants. (Z.S.) 7 refs

  8. Integrated numerical modeling of a landslide early warning system in a context of adaptation to future climatic pressures

    Science.gov (United States)

    Khabarov, Nikolay; Huggel, Christian; Obersteiner, Michael; Ramírez, Juan Manuel

    2010-05-01

    Mountain regions are typically characterized by rugged terrain which is susceptible to different types of landslides during high-intensity precipitation. Landslides account for billions of dollars of damage and many casualties, and are expected to increase in frequency in the future due to a projected increase of precipitation intensity. Early warning systems (EWS) are thought to be a primary tool for related disaster risk reduction and climate change adaptation to extreme climatic events and hydro-meteorological hazards, including landslides. An EWS for hazards such as landslides consist of different components, including environmental monitoring instruments (e.g. rainfall or flow sensors), physical or empirical process models to support decision-making (warnings, evacuation), data and voice communication, organization and logistics-related procedures, and population response. Considering this broad range, EWS are highly complex systems, and it is therefore difficult to understand the effect of the different components and changing conditions on the overall performance, ultimately being expressed as human lives saved or structural damage reduced. In this contribution we present a further development of our approach to assess a landslide EWS in an integral way, both at the system and component level. We utilize a numerical model using 6 hour rainfall data as basic input. A threshold function based on a rainfall-intensity/duration relation was applied as a decision criterion for evacuation. Damage to infrastructure and human lives was defined as a linear function of landslide magnitude, with the magnitude modelled using a power function of landslide frequency. Correct evacuation was assessed with a ‘true' reference rainfall dataset versus a dataset of artificially reduced quality imitating the observation system component. Performance of the EWS using these rainfall datasets was expressed in monetary terms (i.e. damage related to false and correct evacuation). We

  9. Numerical analyses and experiment investigations of an annular micro gas turbine power system using fuels with low heating values

    Institute of Scientific and Technical Information of China (English)

    YANG; ChunHsiang; LEE; ChengChia; HSIAO; JenHao; CHEN; ChiunHsun

    2009-01-01

    This study investigates the effects of using fuels with low heating values on the performance of an annular micro gas turbine(MGT)experimentally and numerically.The MGT used in this study is MW-54, whose original fuel is liquid(Jet A1).Its fuel supply system is re-designed to use biogas fuel with low heating value(LHV).The purpose is to reduce the size of a biogas distributed power supply system and to enhance its popularization.This study assesses the practicability of using fuels with LHVs by using various mixing ratios of methane(CH4)and carbon dioxide(CO2).Prior to experiments,the corresponding simulations,aided by the commercial code CFD-ACE+,were carried out to investigate the cooling effect in a perforated combustion chamber and combustion behavior in an annular MGT when LHV gas was used.The main purposes are to confirm that there are no hot spots occurring in the liners and the exhaust temperatures of combustor are lower than 700°C when MGT is operated under different conditions.In experiments,fuel pressure and mass flow rate,turbine rotational speed,generator power output,and temperature distribution were measured to analyze MGT performance.Experimental results indicate that the presented MGT system operates successfully under each tested condition when the minimum heating value of the simulated fuel is approximately 50%of pure methane.The power output is around 170 W at 85000 r/min as 90%CH4 with 10%CO2 is used and 70 W at 60000 r/min as 70%CH4 with 30%CO2 is used.When a critical limit of 60%CH4 is used,the power output is extremely low. Furthermore,the best theoretical Brayton cycle efficiency for such MGT is calculated as 23%according to the experimental data while LHV fuel is used.Finally,the numerical results and experiment results reveal that MGT performance can be improved further and the possible solutions for performance im- provement are suggested for the future studies.

  10. Numerical analyses and experiment investigations of an annular micro gas turbine power system using fuels with low heating values

    Institute of Scientific and Technical Information of China (English)

    YANG ChunHsiang; LEE ChengChia; HSIAO JenHao; CHEN ChiunHsun

    2009-01-01

    This study investigates the effects of using fuels with low heating values on the performance of an annular micro gas turbine(MGT)experimentally and numerically.The MGT used in this study is MW-54,whose original fuel is liquid(Jet al).Its fuel supply system is re-designed to use biogas fuel with low heating value(LHV).The purpose is to reduce the size of a biogas distributed power supply system and to enhance its popularization.This study assesses the practicability of using fuels with LHVs by using various mixing ratios of methane(CH_4)and carbon dioxide(CO_2).Prior to experiments,the corresponding simulations,aided by the commercial code CFD-ACE+,were carried out to investigate the cooling effect in a perforated combustion chamber and combustion behavior in an annular MGT when LHV gas was used.The main purposes are to confirm that there are no hot spots occurring in the liners and the exhaust temperatures of combustor are lower than 700℃ when MGT is operated under different conditions,in experiments,fuel pressure and mass flow rate,turbine rotational speed,generator power output,and temperature distribution were measured to analyze MGT performance.Experimental results indicate that the presented MGT system operates successfully under each tested condition when the minimum heating value of the simulated fuel is approximately 50%of pure methane.The power output is around 170 W at 85000 r/min as 90%CH_4 with 10%CO_2 is used and 70 W at 60000 r/min as 70%CH_4 with 30%CO_2 is used.When a critical limit of 60%CH_4 is used,the power output is extremely low.Furthermore,the best theoretical Brayton cycle efficiency for such MGT is calculated as 23%according to the experimental data while LHV fuel is used.Finally,the numerical results and experiment results reveal that MGT performance can be improved further and the possible solutions for performance improvement are suggested for the future studies.

  11. Analyses of possible changes in intense and extreme wind speeds over northern Europe under climate change scenarios

    DEFF Research Database (Denmark)

    Pryor, Sara; Barthelmie, Rebecca Jane; Clausen, Niels-Erik; Drews, Martin; MacKellar, N.; Kjellström, E.

    Regional Climate Models. Additionally, internal (inherent) variability and initial conditions exert a strong impact on projected wind climates throughout the twenty-first century. Simulations of wind gusts by one of the RCMs (RCA3) indicate some evidence for increased magnitudes (of up to +10%) in the...... be used in interpreting this inference given the high degree of wind climate projection spread that derives from the specific AOGCM and RCM used in the downscaling....

  12. Analyses of Numerical Responses and Main Life Parameters for Determining the Suppression of Amblyseius cucumeris on Panonychus citri

    Institute of Scientific and Technical Information of China (English)

    ZHANG Yan-xuan; LIN Jian-zhen; JI Jie; CHEN Xie; KANG Yu-mei

    2005-01-01

    In this paper, the numeral response and main parameters of experimental population life table were analyzed for determiningthe suppressing ability of Amblyseius cucumeris on Panonychus citri. The result showed that: (1) Under 21-31 ℃ and 1-9 prey densities/leaf fragment condition, the prey consumptions ofA. cucumeris increased with the temperature or prey density; (2) In 1:3 predator-prey ratio treatment, the suppression ofP. citri (Ro=34.0053; T=19.4369; t=3.8204) was rather weak, it was enhanced as the ratio over 5:30, and the populations ofP. citri in these treatments can be fully controlled within 4-5 days; (3) Under 25±1℃, 80-85% RH and 15L: 9D illumination conditions, the net reproductive rate, mean generation duration and the time for population double increase ofP. citri (Ro=34.0053; T=19.4369; t=3.8204) were higher than those ofA. cucumeris (Ro=21.8750; T=16.8943; t=3.7954). While the intrinsic rate of increase and finite rate of increase of the former (rm=0.1814; λ= 1.1989) were lower than those of the latter (rm=0.1826; λ= 1.2004). These results indicated that A. cucumeris is a desirable bio-control agent to suppress P. citri at lower population stage in citrus orchard.

  13. Failure assessments of corroded pipelines with axial defects using stress-based criteria: Numerical studies and verification analyses

    International Nuclear Information System (INIS)

    Conventional procedures used to assess the integrity of corroded piping systems with axial defects generally employ simplified failure criteria based upon a plastic collapse failure mechanism incorporating the tensile properties of the pipe material. These methods establish acceptance criteria for defects based on limited experimental data for low strength structural steels which do not necessarily address specific requirements for the high grade steels currently used. For these cases, failure assessments may be overly conservative or provide significant scatter in their predictions, which lead to unnecessary repair or replacement of in-service pipelines. Motivated by these observations, this study examines the applicability of a stress-based criterion based upon plastic instability analysis to predict the failure pressure of corroded pipelines with axial defects. A central focus is to gain additional insight into effects of defect geometry and material properties on the attainment of a local limit load to support the development of stress-based burst strength criteria. The work provides an extensive body of results which lend further support to adopt failure criteria for corroded pipelines based upon ligament instability analyses. A verification study conducted on burst testing of large-diameter pipe specimens with different defect length shows the effectiveness of a stress-based criterion using local ligament instability in burst pressure predictions, even though the adopted burst criterion exhibits a potential dependence on defect geometry and possibly on material's strain hardening capacity. Overall, the results presented here suggests that use of stress-based criteria based upon plastic instability analysis of the defect ligament is a valid engineering tool for integrity assessments of pipelines with axial corroded defects

  14. Observational analyses and numerical simulations of the transition of a tropical wave critical layer to a tropical depression

    Science.gov (United States)

    Montgomery, M. T.

    2009-04-01

    In recent research my collaborators and I have hypothesized that tropical cyclones in the deep Atlantic and eastern Pacific basins develop from the cyclonic Kelvin Cat's eye of a tropical easterly wave critical layer located equatorward of the easterly jet axis that typifies the trade wind belt. The genesis sequence is likened to the development of a marsupial infant in its mother's pouch, and for this reason has been dubbed the "Marsupial Paradigm". In this talk I will summarize our previous observational findings using the ERA-40, TRMM and best-track data sets and then report on our first multi-scale numerical test of the Marsupial Paradigm that revisits the enigmatic problem of the transformation of an idealized African easterly wave-like disturbance into a tropical storm vortex. The results are found to support key elements of the Marsupial Paradigm by demonstrating the existence of a vorticity dominant region with minimal strain within the critical layer pouch that contains strong cyclonic vorticity and high saturation fraction. This localized region within the pouch serves as the "attractor" for an upscale "bottom up" development process while the wave and pouch move together. As part of the research, I will also report on our findings concerning the evolution of stratiform vs. convective precipitation within the Cat's eye. It is shown that moist deep convection is sustained near the center of the Cat's eye. The convergence profile within the Cat's eye is found to become dominantly convective with persistent convection. Low-level convergence plays a key role in establishing and intensifying the near-surface circulation, while the non-advective vorticity flux and the mid-level convergence associated with stratiform precipitation help to increase the mid-level circulation and build a tropospheric-deep vortex. Implications of these findings are discussed in relation to a newly proposed field experiment for the most active period of the Atlantic hurricane season

  15. Design and analysis of high-numerical-aperture beam shaping systems; Design und Analyse von Strahlformungssystemen hoher numerischer Apertur

    Energy Technology Data Exchange (ETDEWEB)

    Schweitzer, Hagen

    2009-11-24

    The generation of light tailored to measure stands today in the center of many innovative applications. A possibility of the flexible manipulation of light is the laser-beam shaping.Aim is thereby to transform the intensity profile of a laser beam to a wanted profile. The main topic of this thesis is the modeling and propagation of laser light in paraxial and non-paraxial beam-shaping systems as well as the optimization of these systems by means of a generalized projection algorithm. This algorithm is applied for the optimization by means of aspherical formula or polynomials point-by-point parametrized beam shaping surfaces. It is shown that during the optimization a regardment of diffraction, interference, and abberations is possible. The latter can not only be regarded, but directly used for the beam shaping. Finally it is shown that the aberrations of spherical catalogue lenses are already sufficient for some beam-shaping applications. The efficiency of the developed optimization algorithms is demonstrated both on paraxial and on non-paraxial beam-shaping examples with a numerical aperture of up to 0.62. Finally in the present thesis concepts for the achromatization and for the wave-length multiplexing are introduced, which are based on the application of diverse surfaces and materials with different dispersion. While the achromatization aims to make the optical function of a beam-shaping system wave-length independent, the wavelength multiplexing tries directly to realize different optical functions for diverse design wavelengths. [German] Die Erzeugung massgeschneiderten Lichts steht heute im Mittelpunkt vieler innovativer Anwendungen. Eine Moeglichkeit der flexiblen Manipulation von Licht ist die Laserstrahlformung. Ziel ist es dabei, das Intensitaetsprofil eines Laserstrahls in ein gewuenschtes Profil umzuformen. Schwerpunkt dieser Arbeit ist die Modellierung und Ausbreitung von Laserlicht in paraxialen und nicht-paraxialen Strahlformungssystemen sowie die

  16. Magnetic and Sedimentological Analyses of Sediment Cores from Otsego Lake Reveal Climate and Possible Delta Dynamics Throughout the Holocene

    Science.gov (United States)

    Geiss, C. E.; Hasbargen, L. E.

    2015-12-01

    Otsego Lake (42°43'N, -74°54'W) is a large oligotrophic, monomictic lake in upstate New York that occupies a narrow, N-S trending basin (approx. 13 km length, 2 km width) and has a maximum water depth of approx. 50 m. We collected two sediment cores from a shallow (4 m water depth) bench near the SW shore of the lake. The cores were collected approximately 200 m off-shore from a small stream delta. Age control was established through five 14C AMS-dates obtained from terrestrial plant macrofossils. We analyzed sediments for their magnetic properties (magnetic susceptibility, anhysteretic- and isothermal remanent magnetization, hysteresis properties and coercivity distributions) and performed loss-on-ignition and X-ray analyses to determine the relative abundance of organic matter, quartz and calcite. The watershed of Otsego Lake rests in glacial debris and Devonian shale and limestone. The base of the core (> 9 ka) consists mostly of silt-sized, massive to weakly laminated siliceous and strongly magnetic sediments. Between 8-9 ka the climate warmed sufficiently to allow for the formation of calcareous sediments. Between 8 - 6 ka magnetic minerals are characterized by low abundance and small grainsize, while organic and inorganic carbon increase. Sedimentation rates decrease significantly between 6-2 ka (from ~100 cm/ka to 12-15 cm/ka). During this time interval the relative abundance of quartz increases, sediment becomes slightly more magnetic, and the magnetic grain-size increases as well. We interpret this time period as a low-stand, when lower lake levels allow for the redeposition and possible loss of sediment into the deeper part of the lake, as well as increased terrigenous input from the nearby lakeshore. This lowstand is clearly identified as a strong, continuous reflector in GPR profiles. Sediments younger than 2 ka are characterized by variable abundances of magnetic minerals, with magnetic remanence peaks appearing semi-periodically approximately every

  17. Physical and numerical modelling of permafrost dynamic during a climatic cycle: implications for Meuse - Haute-Marne site

    International Nuclear Information System (INIS)

    This manuscript deals about works realized on the permafrost modelling in porous media and its impact on the hydrogeological circulations. These are parts of the Andra's studies on the nuclear waste storage and, on the environmental studies of the Meuse/Haute-Marne (MHM) site. During a climatic cycle, cold periods can generate permafrost (ground with temperature lower than 0 C for 2 consecutive years). This peri-glacial structure propagates towards deep geological layers, and, due to its very low permeability, can stop the flow of water bodies like aquifers. This work presents the elaboration of two numerical models (with Cast3M code (CEA)): (i) a model with thermal conduction, used for the study of a cold wave propagation in porous media with phase transition (water-ice); (ii) a more complex model, managing the thermo-hydraulic coupling of ground phenomenon (conduction, convection and transition of phase). After validation, these two models offer three axes of development: (i) benchmark proposition by the study of two generic test-cases; (ii) study of the local air temperature signal on MHM site: importance of high frequency temperature variations (centennial scale) for permafrost depth and stability; (iii) study of the dynamics of a thermal discontinuity in a typical hydrological system river-plain: closure time of the system by the permafrost according to various parameters (temperatures, geothermal flow, hydrological flow directions). (author)

  18. 3D numerical analyses for the quantitative risk assessment of subsidence and water flood due to the partial collapse of an abandoned gypsum mine.

    Science.gov (United States)

    Castellanza, R.; Orlandi, G. M.; di Prisco, C.; Frigerio, G.; Flessati, L.; Fernandez Merodo, J. A.; Agliardi, F.; Grisi, S.; Crosta, G. B.

    2015-09-01

    After the abandonment occurred in the '70s, the mining system (rooms and pillars) located in S. Lazzaro di Savena (BO, Italy), grown on three levels with the method rooms and pillars, has been progressively more and more affected by degradation processes due to water infiltration. The mine is located underneath a residential area causing significant concern to the local municipality. On the basis of in situ surveys, laboratory and in situ geomechanical tests, some critical scenarios were adopted in the analyses to simulate the progressive collapse of pillars and of roofs in the most critical sectors of the mine. A first set of numerical analyses using 3D geotechnical FEM codes were performed to predict the extension of the subsidence area and its interaction with buildings. Secondly 3D CFD analyses were used to evaluated the amount of water that could be eventually ejected outside the mine and eventually flooding the downstream village. The predicted extension of the subsidence area together with the predicted amount of the ejected water have been used to design possible remedial measurements.

  19. A simple object-oriented and open-source model for scientific and policy analyses of the global climate system - Hector v1.0

    Science.gov (United States)

    Hartin, C. A.; Patel, P.; Schwarber, A.; Link, R. P.; Bond-Lamberty, B. P.

    2015-04-01

    Simple climate models play an integral role in the policy and scientific communities. They are used for climate mitigation scenarios within integrated assessment models, complex climate model emulation, and uncertainty analyses. Here we describe Hector v1.0, an open source, object-oriented, simple global climate carbon-cycle model. This model runs essentially instantaneously while still representing the most critical global-scale earth system processes. Hector has a three-part main carbon cycle: a one-pool atmosphere, land, and ocean. The model's terrestrial carbon cycle includes primary production and respiration fluxes, accommodating arbitrary geographic divisions into, e.g., ecological biomes or political units. Hector actively solves the inorganic carbon system in the surface ocean, directly calculating air-sea fluxes of carbon and ocean pH. Hector reproduces the global historical trends of atmospheric [CO2], radiative forcing, and surface temperatures. The model simulates all four Representative Concentration Pathways (RCPs) with equivalent rates of change of key variables over time compared to current observations, MAGICC (a well-known simple climate model), and models from the 5th Coupled Model Intercomparison Project. Hector's flexibility, open-source nature, and modular design will facilitate a broad range of research in various areas.

  20. Characterization of rapid climate changes through isotope analyses of ice and entrapped air in the NEEM ice core

    DEFF Research Database (Denmark)

    Guillevic, Myriam

    of Northern hemisphere ice sheets, known as Heinrich events. The imprint of DO and Heinrich events is also recorded at mid to low latitudes in different archives of the northern hemisphere. A detailed multi-proxy study of the sequence of these rapid instabilities is essential for understanding the climate......Greenland ice core have revealed the occurrence of rapid climatic instabilities during the last glacial period, known as Dansgaard-Oeschger (DO) events, while marine cores from the North Atlantic have evidenced layers of ice rafted debris deposited by icebergs melt, caused by the collapse......-ice extent in the Nordic seas. Finally, we develop a multi-proxy approach to identify in polar ice cores the fingerprint of Heinrich Events and apply it to Heinrich events 4 and 5, occurring during GS-9 and GS-13 respectively. Our multi-proxy study evidences non-synchronous climate changes between Greenland...

  1. Study on convective mixing for thermal striping phenomena. Experimental analyses on mixing process in parallel triple-jet and comparisons between numerical methods

    International Nuclear Information System (INIS)

    A quantitative evaluation on thermal striping, in which temperature fluctuation due to convective mixing imposes thermal fatigue on structural components, is of importance for reactor safety. As for convective mixing in fluid, a water experiment was performed on vertical, parallel triple-jet: a cold jet at the center and hot jets in both side. Mixing behavior between the triple jets and frequency characteristics of temperature fluctuation were obtained by temperature measurement. Three kinds of numerical analyses based on the finite difference method for the experiment were carried out. Two types of turbulence models were used in the calculations, namely k-i two equation turbulence model (k-i Model) and low Reynolds number turbulence stress and heat flux equation model (LRSFM). Furthermore, a direct numerical simulation (DNS) was performed. The DNS could simulate the time-averaged temperature field in the experiment. The results obtained from the k-i Model and the LRSFM reached uniform temperature more downstream than in the experiment and overestimated the temperature fluctuation intensities in the mixing region. As for the prominent frequency in temperature fluctuation due to oscillation of the jets, the frequency obtained by the LRSFM was in good agreement with that in the experiment. The profile of power spectrum density of temperature fluctuations calculated by the DNS was close to the experimental results. The DNS is applicable to the convective mixing of multiple jets. (author)

  2. Late Frasnian-Famennian climates based on palynomorph analyses and the question of the Late Devonian glaciations

    Science.gov (United States)

    Streel, Maurice; Caputo, Mário V.; Loboziak, Stanislas; Melo, José Henrique G.

    2000-11-01

    Palynomorph distribution in Euramerica and western Gondwana, from the Latest Givetian to the Latest Famennian, may be explained, to some extent, by climatic changes. Detailed miospore stratigraphy dates accurately the successive steps of these changes. Interpretation is built on three postulates which are discussed: Euramerica at slightly lower latitudes than generally accepted by most paleomagnetic reconstructions; a conodont time-scale accepted as the most used available subdivision of time; and Late Devonian sea-level fluctuations mainly governed by glacio-eustasy. The Frasnian-Famennian timescale is also evaluated. The comparison, based on conodont correlations, between Givetian and most of the Frasnian miospore assemblages from, respectively, northern and southern Euramerica demonstrates a high taxonomic diversity in the equatorial belt and much difference between supposed equatorial and (sub) tropical vegetations. On the contrary, a similar vegetation pattern and therefore probably compatible climatic conditions were present from tropical to subpolar areas. A rather hot climate culminated during the Latest Frasnian when equatorial miospore assemblages reached their maximum width. The miospore diversity shows also a rather clear global Late Frasnian minimum which is also recorded during the Early and Middle Famennian but only in low latitude regions while, in high latitude, very cold climates without perennial snow may explain the scarcity of miospores and so, of vegetation. The Early and Middle Famennian conspicuous latitudinal gradient of the vegetation seems to attenuate towards the Late and Latest Famennian but this might be above all the result of the development, of cosmopolitan coastal lowland vegetations (downstream swamps) depending more on the moisture and equable local microclimates than on the probably adverse climates of distant hinterland areas. During that time, periods of cold climate without perennial snow cover and with rare vegetation may

  3. Energy and climate change: the main analyses of Regards sur la Terre. An annual publication on sustainable development

    International Nuclear Information System (INIS)

    In November 2006, the French Development Agency, AFD (Agence francaise de developpement) and the Institute for Sustainable Development and International Relations, IDDRI (Institut du developpement durable et des relations internationales) launched an annual publication on sustainable development in a global perspective, Regards sur la Terre, published by Les Presses de Sciences Po (Paris). Regards sur la Terre includes an analysis of the most important international events of the last twelve months in the field of sustainable development, along with a thematic section, which in the first edition focused on energy and climate change. This booklet presents the overall introduction of the 2007 publication and the introduction of its thematic section, as well as a selection of the main chapters dealing with the theme of energy and climate change. Contents: Awakening and crisis of confidence; Reorienting our Societies; Energy in the world: Challenges and prospects; Challenges and constraints for energy supply: The coal hard facts; Satisfying energy growth in emerging countries; Diversifying power generation in China; From Rio to Marrakech: Development in climate negotiations; An international coordination regime come what may; The perspective of developing countries; An American 'point of view'

  4. Preliminary assessment of late quaternary vegetation and climate of southeastern Utah based on analyses of packrat middens

    International Nuclear Information System (INIS)

    Packrat midden sequences from two caves (elevations 1585 and 2195 m; 5200 and 7200 ft) southwest of the Abajo Mountains in southeast Utah record vegetation changes that are attributed to climatic changes occurring during the last 13,000 years. These data are useful in assessing potential future climates at proposed nuclear waste sites in the area. Paleoclimates are reconstructed by defining modern elevational analogs for the vegetation assemblages identified in the middens. Based on the midden record, a climate most extreme from the present occurred prior to approximately 10,000 years before present (BP), when mean annual temperature was probably 3 to 4C (5.5 to 7F) cooler than present. However, cooling could not have exceeded 5C (9F) at 1585 m (5200 ft). Accompanying mean annual precipitation is estimated to have been from 35 to 140% greater than at present, with rainfall concentrated in the winter months. Vegetational changes beginning approximately 10,000 years BP are attributed to increased summer and mean annual temperatures, a decreasing frequency of spring freezes, and a shift from winter- to summer-dominant rainfall. Greater effective moisture than present is inferred at both cave sites from approximately 8000 to 4000 years BP. Modern flora was present at both sites by about 2000 years BP

  5. Evolution of the East Antarctic Ice Sheet: a numerical study on the role of the dissipation-strain rate feedback with changing climate

    OpenAIRE

    Huybrechts, P.; Oerlemans, J.

    1988-01-01

    An efficient numerical ice-sheet model, including time dependence and full thermo-mechanical coupling, has been developed in order to investigate the thermal regime and overall configuration of a polar ice sheet with respect to changing environmental conditions. From basic sensitivity experiments, in which a schematic East Antarctic ice sheet is forced with a typical glacial-interglacial climatic shift, it is found that: (i) the mutual interaction of temperature and deformation has a stabiliz...

  6. Numerical-experimental analyses by Hot-Wire method of an alumina cylinder for future studies on thermal conductivity of the fusion breeder materials

    International Nuclear Information System (INIS)

    The determination of the thermal conductivity of breeder materials is one of the main goal in order to find the best candidate material for the fusion reactor technology. Experimental tests have been and will be carried out with a dedicated experimental devices, built at the Department of Civil and Industrial Engineering of the University of Pisa. The methodological approach used in doing that is characterized by two main phases strictly interrelated each other: the first one focused on the experimental evaluation of thermal conductivity of a ceramic material, by means of hot wire method, to be subsequently used in the second phase, based on the test rig method, to determine the thermal conductivity of pebble bed material. To the purpose, two different experimental devices have been designed and built. This paper deals with the first phase of the methodology. In this framework, the equipment set up and built to perform Hot wire tests, the ceramic material (a cylinder of alumina), the experimental procedure and the measured results obtained varying the temperature, are presented and discussed. The experimental campaign has been lead from 50°C up to 400°C. The thermal conductivity of the ceramic material at different bulk temperatures has been obtained in stationary conditions (detected on the basis of the temperature values measured during the experiment). Numerical analyses have been also performed by means of FEM code Ansys©. The numerical results were in quite good agreement with the experimental one, confirming also the reliability of code in reproducing heat transfer phenomena

  7. The climate station of the University of Hohenheim: analyses of air temperature and precipitation time series since 1878

    Science.gov (United States)

    Wulfmeyer, Volker; Henning-Müller, Ingeborg

    2006-01-01

    At the University of Hohenheim (UHOH), one of the longest records in Germany concerning meteorological surface data exists. Since the late nineteenth century, time series of several surface variables such as temperature, precipitation, wind and relative humidity have been measured. Particularly, since 1878, almost continuous time series of temperature and precipitation are available.We are focusing our analysis on temperature as well as on precipitation. We demonstrate that the UHOH data provide another homogeneous, and from other sources, independent time record. Its errors are also well specified.Long time series are essential for investigating climate trends as well as statistics of extreme events. We are investigating trends in temperature and compare these to climatologies. We observe an increase in temperature of about 0.6 °C between 1971 and 2000 in comparison to the average between 1878 and 2002. Not only this amount but also the shape of the temperature curve are in striking agreement with trends assessed by the Intergovernmental Panel on Climate Change in the Northern Hemisphere. It shows also the same behavior of the Climate Research Unit (CRU) climatology using the grid point surrounding our measurement site. This demonstrates a low influence of local effects on the temperature trend at our measurement site. It also indicates that temperature fields have a large spatial correlation length. We found a reduction of 2.2 frost days and a reduction of 1.2 ice days per decade. In the summer of 2003, the mean temperature was 21.8 °C, which was 5 standard deviations larger than the mean value of 16.9 °C between 1878 and 2002.The precipitation patterns at our site show a significant increase of precipitation in winter, whereas in summer a trend is not significant. Particularly in winter, we find an increase of 12%. We also detected indications of a shift of precipitation to more extreme values.

  8. Characteristics of pressure buildup from local fuel-coolant interactions in a simulated molten fuel pool. 2. Numerical analyses using SIMMER-III

    International Nuclear Information System (INIS)

    Analyses of severe accidents for sodium-cooled fast reactors have shown that by assuming pessimistic conditions the accident might proceed into a transition phase where a whole-core-scale pool containing sufficient fuel to exceed prompt criticality by fuel compaction might be formed. Local fuel-coolant interaction in the pool is regarded as one of the probable initiators that could lead to such compactive fluid motions. To clarify the mechanisms underlying this interaction, in the past years a series of simulated experiments, which covers a variety of conditions including much difference in water volume, melt temperature and water subcooling, was conducted at the Japan Atomic Energy Agency by delivering a given quantity of water into a molten pool formed with a low-melting-point alloy. In this study, motivated by acquiring further evidence for understanding its mechanism, SIMMER-III, an advanced fast reactor safety analysis code, is utilized for analyses. It is found that, similar to experiments, the water volume and melt temperature are observable to have remarkable impact on the pressure buildup during local FCIs, while the role of water subcooling seems to be less prominent. In addition, from the numerical runs performed it is also inferable that the most probable reason leading to the limited pressurization for a given melt and water temperature within the non-film boiling range, even under a condition of much larger volume of water delivered into the pool, should be due to an isolation effect of vapor bubbles generated at the water-melt interface. Knowledge and data from this study might be utilized for potential empirical-model development as well as further investigations using reactor material in the future. (author)

  9. Basic Diagnosis and Prediction of Persistent Contrail Occurrence using High-resolution Numerical Weather Analyses/Forecasts and Logistic Regression. Part I: Effects of Random Error

    Science.gov (United States)

    Duda, David P.; Minnis, Patrick

    2009-01-01

    Straightforward application of the Schmidt-Appleman contrail formation criteria to diagnose persistent contrail occurrence from numerical weather prediction data is hindered by significant bias errors in the upper tropospheric humidity. Logistic models of contrail occurrence have been proposed to overcome this problem, but basic questions remain about how random measurement error may affect their accuracy. A set of 5000 synthetic contrail observations is created to study the effects of random error in these probabilistic models. The simulated observations are based on distributions of temperature, humidity, and vertical velocity derived from Advanced Regional Prediction System (ARPS) weather analyses. The logistic models created from the simulated observations were evaluated using two common statistical measures of model accuracy, the percent correct (PC) and the Hanssen-Kuipers discriminant (HKD). To convert the probabilistic results of the logistic models into a dichotomous yes/no choice suitable for the statistical measures, two critical probability thresholds are considered. The HKD scores are higher when the climatological frequency of contrail occurrence is used as the critical threshold, while the PC scores are higher when the critical probability threshold is 0.5. For both thresholds, typical random errors in temperature, relative humidity, and vertical velocity are found to be small enough to allow for accurate logistic models of contrail occurrence. The accuracy of the models developed from synthetic data is over 85 percent for both the prediction of contrail occurrence and non-occurrence, although in practice, larger errors would be anticipated.

  10. Relation between the sedimentary organic record and the climatic oscilations in the Holocene attested by palynofacies and organic geochemical analyses from a pond of altitude in southern Brazil

    Directory of Open Access Journals (Sweden)

    GABRIELLI T. GADENS-MARCON

    2014-09-01

    Full Text Available This paper presents the quantitative and qualitative results obtained from palynofacies and geochemistry analyses carried out on a core covering approximately 8000 years of sedimentation of a pond of altitude located at the mining district of Ametista do Sul, southernmost Brazil. The main objective of this paper is to consider the paleoclimatic and paleoenvironmental significance of these analyses. The hydrological isolation renders this pond climatically sensitive to variations in pluviometric regime and this enabled infer rainfall events during the early Holocene, which was responsible for the beginning of the processes of water accumulation in the gossan and the sedimentation of the pond. Changes in the pattern of moisture over the time become the drier environment, resulting in the intermittent pattern of water depth that currently exists at the site. The fluctuations in water depth are inferred from the frequency of Botryococcus and other algae, which tend to decrease progressively toward the top where the autochthonous elements are replaced by parautochthonous and allochthonous elements. Pseudoschizaea, in turn, appears to act as a biological marker of these transitional intervals. The present results are of great importance for understanding the extent of climate change and its environmental impacts at regional and global levels.

  11. Final Progress Report submitted via the DOE Energy Link (E-Link) in June 2009 [Collaborative Research: Decadal-to-Centennial Climate & Climate Change Studies with Enhanced Variable and Uniform Resolution GCMs Using Advanced Numerical Techniques

    Energy Technology Data Exchange (ETDEWEB)

    Fox-Rabinovitz, M; Cote, J

    2009-10-09

    The joint U.S-Canadian project has been devoted to: (a) decadal climate studies using developed state-of-the-art GCMs (General Circulation Models) with enhanced variable and uniform resolution; (b) development and implementation of advanced numerical techniques; (c) research in parallel computing and associated numerical methods; (d) atmospheric chemistry experiments related to climate issues; (e) validation of regional climate modeling strategies for nested- and stretched-grid models. The variable-resolution stretched-grid (SG) GCMs produce accurate and cost-efficient regional climate simulations with mesoscale resolution. The advantage of the stretched grid approach is that it allows us to preserve the high quality of both global and regional circulations while providing consistent interactions between global and regional scales and phenomena. The major accomplishment for the project has been the successful international SGMIP-1 and SGMIP-2 (Stretched-Grid Model Intercomparison Project, phase-1 and phase-2) based on this research developments and activities. The SGMIP provides unique high-resolution regional and global multi-model ensembles beneficial for regional climate modeling and broader modeling community. The U.S SGMIP simulations have been produced using SciDAC ORNL supercomputers. The results of the successful SGMIP multi-model ensemble simulations of the U.S. climate are available at the SGMIP web site (http://essic.umd.edu/~foxrab/sgmip.html) and through the link to the WMO/WCRP/WGNE web site: http://collaboration.cmc.ec.gc.ca/science/wgne. Collaborations with other international participants M. Deque (Meteo-France) and J. McGregor (CSIRO, Australia) and their centers and groups have been beneficial for the strong joint effort, especially for the SGMIP activities. The WMO/WCRP/WGNE endorsed the SGMIP activities in 2004-2008. This project reflects a trend in the modeling and broader communities to move towards regional and sub-regional assessments and

  12. A Numerical Simulation Study of Impacts of Historical Land-Use Changes on the Regional Climate in China Since 1700

    Institute of Scientific and Technical Information of China (English)

    LI Qiaoping; DING Yihui; DONG Wenjie

    2007-01-01

    By using the improved regional climate model (BCC_RegCM1.0), a series of modeling experiments are undertaken to investigate the impacts of historical land-use changes (LUCs) on the regional climate in China.Simulations are conducted for 2 years using estimated land-use for 1700, 1800, 1900, 1950, and 1990. The conversion of land cover in these periods was extensive over China, where large areas were altered from forests to either grass or crops, or from grasslands to crops. Results show that, since 1700, historical LUCs have significant effects on regional climate change, with rainfall increasing in the middle and lower reaches of the Yangtze River Basin, Northwest China, and Northeast China, but decreasing by different degrees in other regions. The air temperature shows significant warming over large areas in recent hundred years,especially from 1950 to 1990, which is consistent with the warming caused by increasing greenhouse gases.On the other hand, historical LUCs have obvious effects on mean circulation, with the East Asian winter and summer monsoonal flows becoming more intensive, which is mainly attributed to the amplified temperature difference between ocean and land due to vegetation change. Thus, it would be given more attention to the impacts of LUCs on regional climate change.

  13. Numerical climate modeling and verification of selected areas for heat waves of Pakistan using ensemble prediction system

    International Nuclear Information System (INIS)

    Depending upon the topography, there is an extreme variation in the temperature of Pakistan. Heat waves are the Weather-related events, having significant impact on the humans, including all socioeconomic activities and health issues as well which changes according to the climatic conditions of the area. The forecasting climate is of prime importance for being aware of future climatic changes, in order to mitigate them. The study used the Ensemble Prediction System (EPS) for the purpose of modeling seasonal weather hind-cast of three selected areas i.e., Islamabad, Jhelum and Muzaffarabad. This research was purposely carried out in order to suggest the most suitable climate model for Pakistan. Real time and simulated data of five General Circulation Models i.e., ECMWF, ERA-40, MPI, Meteo France and UKMO for selected areas was acquired from Pakistan Meteorological Department. Data incorporated constituted the statistical temperature records of 32 years for the months of June, July and August. This study was based on EPS to calculate probabilistic forecasts produced by single ensembles. Verification was done out to assess the quality of the forecast t by using standard probabilistic measures of Brier Score, Brier Skill Score, Cross Validation and Relative Operating Characteristic curve. The results showed ECMWF the most suitable model for Islamabad and Jhelum; and Meteo France for Muzaffarabad. Other models have significant results by omitting particular initial conditions.

  14. Analysing the emission gap between pledged emission reductions under the Cancun Agreements and the 2C climate target

    Energy Technology Data Exchange (ETDEWEB)

    Den Elzen, M.G.J.; Roelfsema, M.; Hof, A.F. [Netherlands Environmental Assessment Agency PBL, Den Haag (Netherlands); Boettcher, H. [Institute for Applied Systems Analysis IIASA, Laxenburg (Austria); Grassi, G. [Joint Research Centre JRC, European Commission, Ispra (Italy)

    2012-04-15

    In the Cancun Agreements, Annex I Parties (industrialised countries) and non-Annex I Parties (developing countries) made voluntary pledges to reduce greenhouse gas emissions by 2020. The Cancun Agreements also state a long-term target of limiting temperature increase to a maximum of 2C above pre-industrial levels. This report is an update of the PBL report 'Evaluation of the Copenhagen Accord', which similar to earlier studies showed that there is a possible gap in emissions between the emission level resulting from the pledges and the level necessary to achieve the 2C target. The updates involve new information on many topics that have become available over the last two years, including updated national business-as-usual emission projections as provided by the countries themselves, and more information on uncertainties and on factors influencing the size of the emission gap. In this context, the main objective of this report can be formulated as follows: This report analyses the effect of the pledges put forward by the Parties in the Cancun Agreements on the emission gap, taking into account all the new information available. It pays specific attention to uncertainties and risks and describes in more detail the emission implications of the pledges and actions of the 12 largest emitting countries or regions.

  15. Exploiting the weekly cycle as observed over Europe to analyse aerosol indirect effects in two climate models

    Directory of Open Access Journals (Sweden)

    J. Quaas

    2009-05-01

    Full Text Available A weekly cycle in aerosol pollution and meteorological quantities is observed over Europe. In the present study we exploit this effect to analyse aerosol-cloud-radiation interactions. A weekly cycle is imposed on anthropogenic emissions in two general circulation models that include parameterizations of aerosol cycles and cloud microphysics. It is found that the simulated weekly cycles in sulfur dioxide, sulfate, and aerosol optical depth in both models agree reasonably well with the observed ones indicating model skill in simulating the aerosol cycle. A distinct weekly cycle in cloud droplet number concentration is demonstrated in both observations and models. For other variables, such as cloud liquid water path, cloud cover, top-of-the-atmosphere radiation fluxes, precipitation, and surface temperature, large variability and contradictory results between observations, model simulations, and model control simulations without a weekly cycle in emissions prevent us from reaching any firm conclusions about the potential aerosol impact on meteorology or the realism of the modeled second aerosol indirect effects.

  16. The CM SAF SSM/I-based total column water vapour climate data record: methods and evaluation against re-analyses and satellite

    Directory of Open Access Journals (Sweden)

    M. Schröder

    2012-09-01

    Full Text Available The "European Organisation for the Exploitation of Meteorological Satellites" (EUMETSAT Satellite Application Facility on Climate Monitoring (CM SAF aims at the provision and sound validation of well documented Climate Data Records (CDRs in sustained and operational environments. In this study, a total column water vapour (WVPA climatology from CM SAF is presented and inter-compared to water vapour data records from various data sources. Based on homogenised brightness temperatures from the Special Sensor Microwave Imager (SSM/I, a climatology of WVPA has been generated within the Hamburg Ocean-Atmosphere Fluxes and Parameters from Satellite (HOAPS framework. Within a research and operation transition activity the HOAPS data and operations capabilities have been successfully transferred to the CM SAF where the complete HOAPS data and processing schemes are hosted in an operational environment. An objective analysis for interpolation, kriging, has been developed and applied to the swath-based WVPA retrievals from the HOAPS data set. The resulting climatology consists of daily and monthly mean fields of WVPA over the global ice-free ocean. The temporal coverage ranges from July 1987 to August 2006. After a comparison to the precursor product the CM SAF SSM/I-based climatology has been comprehensively compared to different types of meteorological analyses from the European Centre for Medium-Range Weather Forecasts (ECMWF-ERA40, ERA INTERIM and operational analyses and from the Japan Meteorological Agency (JMA-JRA. This inter-comparison shows an overall good agreement between the climatology and the analyses, with daily absolute biases generally smaller than 2 kg m−2. The absolute bias to JRA and ERA INTERIM is typically smaller than 0.5 kg m−2. For the period 1991–2006, the root mean square error (RMSE to both reanalysis is approximately 2 kg m−2. As SSM/I WVPA and radiances are assimilated in JMA and all

  17. The CM SAF SSM/I-based total column water vapour climate data record: methods and evaluation against re-analyses and satellite

    Directory of Open Access Journals (Sweden)

    M. Schröder

    2013-03-01

    Full Text Available The European Organisation for the Exploitation of Meteorological Satellites (EUMETSAT Satellite Application Facility on Climate Monitoring (CM SAF aims at the provision and sound validation of well documented Climate Data Records (CDRs in sustained and operational environments. In this study, a total column water vapour path (WVPA climatology from CM SAF is presented and inter-compared to water vapour data records from various data sources. Based on homogenised brightness temperatures from the Special Sensor Microwave Imager (SSM/I, a climatology of WVPA has been generated within the Hamburg Ocean–Atmosphere Fluxes and Parameters from Satellite (HOAPS framework. Within a research and operation transition activity the HOAPS data and operation capabilities have been successfully transferred to the CM SAF where the complete HOAPS data and processing schemes are hosted in an operational environment. An objective analysis for interpolation, namely kriging, has been applied to the swath-based WVPA retrievals from the HOAPS data set. The resulting climatology consists of daily and monthly mean fields of WVPA over the global ice-free ocean. The temporal coverage ranges from July 1987 to August 2006. After a comparison to the precursor product the CM SAF SSM/I-based climatology has been comprehensively compared to different types of meteorological analyses from the European Centre for Medium-Range Weather Forecasts (ECMWF-ERA40, ERA INTERIM and operational analyses and from the Japan Meteorological Agency (JMA–JRA. This inter-comparison shows an overall good agreement between the climatology and the analyses, with daily absolute biases generally smaller than 2 kg m−2. The absolute value of the bias to JRA and ERA INTERIM is typically smaller than 0.5 kg m−2. For the period 1991–2006, the root mean square error (RMSE for both reanalyses is approximately 2 kg m−2. As SSM/I WVPA and radiances are assimilated into JMA and all ECMWF analyses and

  18. Case study Sylt - Consequences and integrated assessment of climate change. Final report; Klimaaenderung und Kueste. Fallstudie Sylt - Integrative Analyse und Bewertung der Folgen von Klimaaenderungen. Endbericht

    Energy Technology Data Exchange (ETDEWEB)

    Fraenzle, O.; Sterr, H.; Daschkeit, A.

    2001-05-01

    This final report deals with the structure of the 'case study Sylt' against the background of climate change and possible consequences. In cooperation with the other projects of the case study an instrument is developed which maintains interdisciplinary communication and cooperation. First the 'System Sylt' is described to identify and specify the relevant aspects of functional relationships between the natural and the social system. The focal points are (1) the first-order impacts of climate change, (2) the potential ecological changes in the near future and (3) the image of the North-Sea island Sylt. With regard to the image of Sylt we find some discrepancies existing between a statical respectively a dynamical view; these discrepancies are inherent parts of the future development. All results are seen in the context of 'Integrated Coastal Zone Management' (ICZM) to derive general and specific recommendations for political action and further research. (orig.) [German] Vor dem Hintergrund von Annahmen bezueglich der zukuenftigen klimatischen Entwicklung werden die Konzeption sowie die Vorgehensweise der integrativen Analyse im Rahmen der Fallstudie Sylt dargestellt. Unter Anbindung an das Sylt-GIS wird ein Instrument entwickelt und erprobt, das die (bislang seltene) fachuebergreifende Analyse von Klimafolgen unterstuetzt. Diese muendet zunaechst in eine Darstellung des 'Systems Sylt' auf der Grundlage der wichtigsten Prozesse und Randbedingungen. Die auf dieser Basis identifizierten Kernberichte des 'Systems Sylt' werden in einem weiteren exemplarisch und unter Einbezug des in den disziplinaeren Teilvorhaben der Fallstudie erarbeiteten Wissens einer vertiefenden Analyse unterzogen. Dabei wird erstens auf den Bereich der Folgen eines moeglichen Klimawandels eingegangen, zweitens auf vergangene und zukuenftig moegliche oekologische Veraenderungen und drittens auf das Sylt-Image. Durch eine detailliertere Analyse des

  19. The use of amino acid analyses in (palaeo-) limnological investigations: A comparative study of four Indian lakes in different climate regimes

    Science.gov (United States)

    Menzel, Philip; Anupama, Krishnamurthy; Basavaiah, Nathani; Das, Brijraj Krishna; Gaye, Birgit; Herrmann, Nicole; Prasad, Sushma

    2015-07-01

    In the present study, we report the results of comprehensive amino acid (AA) analyses of four Indian lakes from different climate regimes. We focus on the investigation of sediment cores retrieved from the lakes but data of modern sediment as well as vascular plant, soil, and suspended particulate matter samples from individual lakes are also presented. Commonly used degradation and organic matter source indices are tested for their applicability to the lake sediments, and we discuss potential reasons for possible limitations. A principal component analysis including the monomeric AA composition of organic matter of all analysed samples indicates that differences in organic matter sources and the environmental properties of the individual lakes are responsible for the major variability in monomeric AA distribution of the different samples. However, the PCA also gives a factor that most probably separates the samples according to their state of organic matter degradation. Using the factor loadings of the individual AA monomers, we calculate a lake sediment degradation index (LI) that might be applicable to other palaeo-lake investigations.

  20. Integrated Assessment on Effects of Short-Lived Climate Pollutants (SLCPs) in Asia based on Numerical Models

    Science.gov (United States)

    Takemura, T.; Sudo, K.; Ueda, K.; Masutomi, Y.; Watanabe, S.; Nakata, M.; Takahashi, H. G.; Goto, D.

    2015-12-01

    Air pollution over the Asian region is a serious social problem. For example, activities of the Climate and Clean Air Coalition (CCAC) under the UNFCCC focus on raising awareness and improving scientific understanding of short-lived climate pollutant (SLCP) impacts and mitigation strategies. Our Japanese research project is searching an optimum reduction path of SLCPs considering climate change, health impacts, and agricultural damages. For this purpose, we use aerosol and chemistry models, SPRINTARS and CHASER, respectively, which have been developed by our group, coupled with a general circulation model, MIROC. In the phase 1 of this project, changes in concentrations and radiative forcing of each major SLCPs originating from China, east Asia, southeast Asia, and south Asia in the last 30 years are estimated with the models. Transient simulations along the new emission scenario, SSPs (Shared Socio-economic Pathways) are executed using the MIROC-SPRINTARS/CHASER with ocean circulation in the phase 2 to analyze full feedbacks including hydrological cycle affected by SLCPs. These simulated results will be utilized to estimate health and agricultural impacts of SLCPs. In this presentation, we discuss the optimum reduction path of SLCPs taking both mitigation of global warming and air pollution into consideration. Acknowledgements: Simulations in this study were executed with the supercomputer system of the National Institute for Environmental Studies, Japan. This study is partly supported by the Environment Research and Technology Development Fund (S-12-3) of the Ministry of the Environment, Japan and JSPS KAKENHI Grant Number 15H01728 and 15K12190.

  1. Mathematical and numerical analysis of hyper-elastic systems and introduction of plasticity; Analyse mathematique et numerique de systemes hyperelastiques et introduction de la plasticite

    Energy Technology Data Exchange (ETDEWEB)

    Kluth, G

    2008-12-15

    The goal is to model mathematically and numerically the dynamic phenomenons for solids in finite plasticity. We suggest a model that we call hyper-elasto-plastic based on hyper-elastic systems of conservation laws and on the use of an equation of state that we have constructed so as to achieve the plastic yield criterion of Von Mises. This model gives exact (analytic) solutions with shock split to flyer-plate experiments. The mathematical analysis of this model is done (hyperbolicity, characteristic fields, involutions and entropy). In the numerical part, we give 1D and 2D Lagrangian schemes which satisfy an entropy criterion. Moreover, thanks to a special discretization of the equations on deformation gradient, we satisfy some discrete involutions. In this work, the degeneracy of the solid model into hydrodynamic models is studied at the continuous level, and achieved at the numerical one. On different problems, we show the validity of our model and our numerical schemes. (author)

  2. Micro and macro pattern analyses of fMRI data support both early and late interaction of numerical and spatial information

    Directory of Open Access Journals (Sweden)

    Jan Lonnemann

    2011-10-01

    In this study we used a numerical landmark task to identify the locus of the interaction between numbers and space. While lying in an MR scanner participants decided on the smaller of two numerical intervals in a visually presented number triplet. The spatial position of the middle number was varied; hence spatial intervals were congruent or incongruent with the numerical intervals. Responses in incongruent trials were slower and less accurate than in congruent trials. By combining across vertex correlations (micro pattern with a cluster analysis (macro pattern we identified three networks that were devoted to number processing, eye movements, and sensory motor functions. Using support vector machine classifiers in different regions of interest along the IPS, the frontal eye fields and supplementary motor area to distinguish between congruent and incongruent trials we were able to distinguish between congruent and incongruent trials in each of the three networks. We suggest that the three identified networks participate in the integration of numerical and spatial information and that the exclusive assumption of either an early or a late interaction between numerical and spatial information does not do justice to the complex interaction between both dimensions.

  3. Modeling and numerical analysis of non-equilibrium two-phase flows; Modelisation et analyse numerique des ecoulements diphasiques en desequilibre

    Energy Technology Data Exchange (ETDEWEB)

    Rascle, P.; El Amine, K. [Electricite de France (EDF), Direction des Etudes et Recherches, 92 - Clamart (France)

    1997-12-31

    We are interested in the numerical approximation of two-fluid models of nonequilibrium two-phase flows described by six balance equations. We introduce an original splitting technique of the system of equations. This technique is derived in a way such that single phase Riemann solvers may be used: moreover, it allows a straightforward extension to various and detailed exchange source terms. The properties of the fluids are first approached by state equations of ideal gas type and then extended to real fluids. For the construction of numerical schemes , the hyperbolicity of the full system is not necessary. When based on suitable kinetic unwind schemes, the algorithm can compute flow regimes evolving from mixture to single phase flows and vice versa. The whole scheme preserves the physical features of all the variables which remain in the set of physical states. Several stiff numerical tests, such as phase separation and phase transition are displayed in order to highlight the efficiency of the proposed method. The document is a PhD thesis divided in 6 chapters and two annexes. They are entitled: 1. - Introduction (in French), 2. - Two-phase flow, modelling and hyperbolicity (in French), 3. - A numerical method using upwind schemes for the resolution of two-phase flows without exchange terms (in English), 4. - A numerical scheme for one-phase flow of real fluids (in English), 5. - An upwind numerical for non-equilibrium two-phase flows (in English), 6. - The treatment of boundary conditions (in English), A.1. The Perthame scheme (in English) and A.2. The Roe scheme (in English). 136 refs. This document represents a PhD thesis in the speciality Applied Mathematics presented par Khalid El Amine to the Universite Paris 6.

  4. Macro economic analyses related to the White Paper No 21 (2011-2012). Norwegian Climate Policy.; Makroanalyser i tilknytning til Klimameldingen 2012

    Energy Technology Data Exchange (ETDEWEB)

    Faehn, Taran; Jacobsen, Karl

    2012-11-01

    We report results from analyses performed for the Ministry of Finance and the Ministry of the Environment of specified climate policy scenarios. The results are computed by means of the model MSG-TECH, which is a computable general equilibrium model that allows for technological abatement options. All the scenarios model the participation in EU emissions trading scheme (ETS), which implies obligations of the firms to mitigate or purchase allowances. The scenarios also include the Kyoto commitments and the Norwegian government's pledges in the wake of the Copenhagen negotiations 2010 to reduce domestic emissions by 30 per cent and 100 per cent by 2020 and 2050, respectively. These ambitions can be met by exploiting international green mechanisms like CDM project funding. The studied scenarios differ in their assumptions about domestic emission prices. None of the scenarios obtain the ambitions set by the Parliament's Climate Agreement in 2008, corresponding to reductions of between 12 and 14 million tons from the reference in 2020. The most ambitious regime in this analysis results in a cut of 4.3 million tons CO{sub 2} equivalents in 2020, while the least ambitious obtains 1.6 million abated tons. In 2050 the cuts constitute between 5.8 and 8.9 million tons CO{sub 2} equivalents. The scenarios P10 and P20 assume a uniform carbon price of all Kyoto gas emissions (except emissions from agriculture). In the former, the uniform price corresponds to the estimated global marginal costs of avoiding a temperature increase above two degrees C. It is operationalised to 280 Nok in 2020 and 1020 Nok in 2050, respectively (in real 2011-prices). This implies that EU ETS sources pay a tax on top of the ETS price that equalise the carbon price within the rest of the economy. This scenario results in a domestic abatement of 2.0 million tons in 2020 and 8.9 million tons in 2050. In the second scenario, the uniform carbon price is assumed to increase faster until 2020

  5. Guidebook for territories' support in the analysis of their socio-economical vulnerability to climate change; Guide d'accompagnement des territoires pour l'analyse de leur vulnerabilite socio-economique au changement climatique

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2011-07-01

    The work of the inter-ministerial group 'Impacts of Climate Change, Adaptation and Associated Costs for France', which met between March 2007 and October 2009, led to a sector-based assessment of all climate change related impacts and of associated adaptation measures. The aim was to obtain quantified elements that could underpin public policy decision-making and especially development of the National Adaptation Plan. While the sectoral analyses focused on quantifying the costs of adaptation, the approach of the 'Territories' group, co-steered by the Datar (regional development delegation) and Ademe (agency for energy management and environment), addressed the subject of interactions between players and activities, both spatial (sharing of resources between different uses, etc.) and temporal (transition from one situation to another, etc.) and the corresponding means for adjustment. It was in this context that the SOeS proposed a methodology for diagnosis of the socio-economic vulnerability of a given sub-national territory in the face of climate change. This document provides a broad-brush outline of the accompanying guidelines developed by Sogreah Consultants SAS for use by local players. A three step approach is followed to draw up the vulnerability profile of a territory: 1 - characterising the territory by the identification of the priority activities and physical features; 2 - using the analysis tools to produce a matrix of indices of vulnerability to climate change per hazard; 3 - drawing up an initial vulnerability profile by bringing together the information from the matrix and that from feedback, either by activity or group of activities, or by environment, depending on aims. The profile leads to identification of the important issues as well as allowing identification of potential impacts to be studied in more depth. Guidelines were tested in three pilot territories facing different climate change issues: Wateringues, in the Nord

  6. Hydrogeological flux scenarios at Forsmark. Generic numerical flow simulations and compilation of climatic information for use in the safety analysis SFR1 SAR-08

    Energy Technology Data Exchange (ETDEWEB)

    Vidstrand, Patrik (Bergab, Goeteborg (SE)); Naeslund, Jens-Ove (Swedish Nuclear Fuel and Waste Management Co., Stockholm (SE)); Hartikainen, Juha (Helsinki Univ. of Technology, Helsinki (FI)); Svensson, Urban (CFE AB, Karlskrona (SE))

    2007-11-15

    In the earlier modelling for SFR-SAFE it was concluded that the groundwater flow would increase with time along with the shoreline displacement. Even though the numerical results are different the same conclusion is drawn after this study. General conclusions from the present study are that: The upper boundary conditions have a significant impact on the groundwater flow in the geosphere. The characteristic of the surface in regards of being a recharge or discharge area affects the results. In general, a discharge area will experience an increase in groundwater flow under changed conditions. The presence of caging fracture zones affects the results, and, for the tested un-frozen SFR situation, the resulting effect is an increase in groundwater flow. Specific conclusions regarding the relative change of groundwater flow due to different surface conditions are that: The permafrost scenarios, along with the development from sporadic permafrost to continuous permafrost, yield increased groundwater flows in unfrozen parts of the domain. The increase is one order of magnitude or less. In the permafrost, the flow is negligible. The ice sheet scenarios yield situations with significantly increased groundwater flow. The results indicate an increase by two to three orders of magnitude. These increased values, however, apply only for short duration intervals. It is possible that such intervals may be only a couple of years. In the selected climate Base variant, repeating the conditions for the last glacial cycle, permafrost conditions occur after 8,000 years. In the climate variant affected by increased greenhouse warming, permafrost conditions do not occur until after more than 50,000 years. In the chosen climate variants, ice sheets reach the Forsmark area and cause significantly increased groundwater flow, after approx60,000 years or more

  7. Hydrogeological flux scenarios at Forsmark. Generic numerical flow simulations and compilation of climatic information for use in the safety analysis SFR1 SAR-08

    International Nuclear Information System (INIS)

    In the earlier modelling for SFR-SAFE it was concluded that the groundwater flow would increase with time along with the shoreline displacement. Even though the numerical results are different the same conclusion is drawn after this study. General conclusions from the present study are that: The upper boundary conditions have a significant impact on the groundwater flow in the geosphere. The characteristic of the surface in regards of being a recharge or discharge area affects the results. In general, a discharge area will experience an increase in groundwater flow under changed conditions. The presence of caging fracture zones affects the results, and, for the tested un-frozen SFR situation, the resulting effect is an increase in groundwater flow. Specific conclusions regarding the relative change of groundwater flow due to different surface conditions are that: The permafrost scenarios, along with the development from sporadic permafrost to continuous permafrost, yield increased groundwater flows in unfrozen parts of the domain. The increase is one order of magnitude or less. In the permafrost, the flow is negligible. The ice sheet scenarios yield situations with significantly increased groundwater flow. The results indicate an increase by two to three orders of magnitude. These increased values, however, apply only for short duration intervals. It is possible that such intervals may be only a couple of years. In the selected climate Base variant, repeating the conditions for the last glacial cycle, permafrost conditions occur after 8,000 years. In the climate variant affected by increased greenhouse warming, permafrost conditions do not occur until after more than 50,000 years. In the chosen climate variants, ice sheets reach the Forsmark area and cause significantly increased groundwater flow, after ∼60,000 years or more

  8. Hydrologic and climatic implications of stable isotope and minor element analyses of authigenic calcite silts and gastropod shells from a mid-Pleistocene pluvial lake, Western Desert, Egypt

    Science.gov (United States)

    Kieniewicz, Johanna M.; Smith, Jennifer R.

    2007-11-01

    Authigenic calcite silts at Wadi Midauwara in Kharga Oasis, Egypt, indicate the prolonged presence of surface water during the Marine Isotope Stage 5e pluvial phase recognized across North Africa. Exposed over an area of ˜ 4.25 km 2, these silts record the ponding of water derived from springs along the Libyan Plateau escarpment and from surface drainage. The δ 18O values of these lacustrine carbonates (- 11.3‰ to - 8.0‰ PDB), are too high to reflect equilibrium precipitation with Nubian aquifer water or water of an exclusively Atlantic origin. Mg/Ca and Sr/Ca of the silts have a modest negative covariance with silt δ 18O values, suggesting that the water may have experienced the shortest residence time in local aquifers when the water δ 18O values were highest. Furthermore, intra-shell δ 18O, Sr/Ca, and Ba/Ca analyses of the freshwater gastropod Melanoides tuberculata are consistent with a perennially fresh water source, suggesting that strong evaporative effects expected in a monsoonal climate did not occur, or that dry season spring flow was of sufficient magnitude to mute the effects of evaporation. The input of a second, isotopically heavier water source to aquifers, possibly Indian Ocean monsoonal rain, could explain the observed trends in δ 18O and minor element ratios.

  9. Interactions between Climate, Socioeconomics, and Land Dynamics in Qinghai Province, China: A LUCD Model-Based Numerical Experiment

    Directory of Open Access Journals (Sweden)

    Xiangzheng Deng

    2013-01-01

    Full Text Available This simulation-based research produces a set of forecast land use data of Qinghai Province, China, applying the land use change dynamics (LUCD model. The simulation results show that the land use pattern will almost keep being consistent in the period from 2010 to 2050 with that in 2000 in Qinghai Province. Grassland and barren or sparsely vegetated land will cover more than 80% of the province’s total area. The land use change will be inconspicuous in the period from 2010 to 2050 involving only 0.49% of the province’s land. The expansion of urban and built-up land, grassland, and barren or sparsely vegetated land and the area reduction of mixed dryland/irrigated cropland and pasture, water bodies, and snow or ice will dominate land use changes of the case study area. The changes of urban and built-up land and mixed dryland/irrigated cropland and pasture will slow down over time. Meanwhile, the change rates of water bodies, snow and ice, barren or sparsely vegetated land, and grassland will show an inverted U-shaped trajectory. Except for providing underlying surfaces for RCMs for future climate change assessment, this empirical research of regional land use change may enhance the understanding of land surface system dynamics.

  10. Petroleum system and thermal history of the Upper Rhine Graben : implications from organic geochemical analyses, oil-source rock correlations and numerical modelling

    OpenAIRE

    Böcker, Johannes

    2015-01-01

    The Upper Rhine Graben (URG) forms the central section of the European Cenozoic Rift System and is a mature hydrocarbon province. During previous exploration periods, about 50 oil fields and several gas fields were discovered accompanied by a huge number of exploration and production wells and numerous seismic profiles. Surprisingly, in 2003 a geothermal well found oil in the Buntsandstein reservoir and discovered unexpectedly the Römerberg oil field, which promptly doubled the total recovera...

  11. Numerical insight into the seismic behavior of eight masonry towers in Northern Italy: FE pushover vs non-linear dynamic analyses

    International Nuclear Information System (INIS)

    This study presents some FE results regarding the behavior under horizontal loads of eight existing masonry towers located in the North-East of Italy. The towers, albeit unique for geometric and architectural features, show some affinities which justify a comparative analysis, as for instance the location and the similar masonry material. Their structural behavior under horizontal loads is therefore influenced by geometrical issues, such as slenderness, walls thickness, perforations, irregularities, presence of internal vaults, etc., all features which may be responsible for a peculiar output. The geometry of the towers is deduced from both existing available documentation and in-situ surveys. On the basis of such geometrical data, a detailed 3D realistic mesh is conceived, with a point by point characterization of each single geometric element. The FE models are analysed under seismic loads acting along geometric axes of the plan section, both under non-linear static (pushover) and non-linear dynamic excitation assumptions. A damage-plasticity material model exhibiting softening in both tension and compression, already available in the commercial code Abaqus, is used for masonry. Pushover analyses are performed with both G1 and G2 horizontal loads distribution, according to Italian code requirements, along X+/− and Y+/− directions. Non-linear dynamic analyses are performed along both X and Y directions with a real accelerogram scaled to different peak ground accelerations. Some few results are presented in this paper. It is found that the results obtained with pushover analyses reasonably well fit expensive non-linear dynamic simulations, with a slightly less conservative trend

  12. Numerical insight into the seismic behavior of eight masonry towers in Northern Italy: FE pushover vs non-linear dynamic analyses

    Science.gov (United States)

    Milani, Gabriele; Valente, Marco

    2015-12-01

    This study presents some FE results regarding the behavior under horizontal loads of eight existing masonry towers located in the North-East of Italy. The towers, albeit unique for geometric and architectural features, show some affinities which justify a comparative analysis, as for instance the location and the similar masonry material. Their structural behavior under horizontal loads is therefore influenced by geometrical issues, such as slenderness, walls thickness, perforations, irregularities, presence of internal vaults, etc., all features which may be responsible for a peculiar output. The geometry of the towers is deduced from both existing available documentation and in-situ surveys. On the basis of such geometrical data, a detailed 3D realistic mesh is conceived, with a point by point characterization of each single geometric element. The FE models are analysed under seismic loads acting along geometric axes of the plan section, both under non-linear static (pushover) and non-linear dynamic excitation assumptions. A damage-plasticity material model exhibiting softening in both tension and compression, already available in the commercial code Abaqus, is used for masonry. Pushover analyses are performed with both G1 and G2 horizontal loads distribution, according to Italian code requirements, along X+/- and Y+/- directions. Non-linear dynamic analyses are performed along both X and Y directions with a real accelerogram scaled to different peak ground accelerations. Some few results are presented in this paper. It is found that the results obtained with pushover analyses reasonably well fit expensive non-linear dynamic simulations, with a slightly less conservative trend.

  13. Numerical insight into the seismic behavior of eight masonry towers in Northern Italy: FE pushover vs non-linear dynamic analyses

    Energy Technology Data Exchange (ETDEWEB)

    Milani, Gabriele, E-mail: milani@stru.polimi.it, E-mail: gabriele.milani@polimi.it; Valente, Marco [Department of Architecture, Built Environment and Construction Engineering (ABC), Politecnico di Milano, Piazza Leonardo da Vinci 32, 20133 Milan (Italy)

    2015-12-31

    This study presents some FE results regarding the behavior under horizontal loads of eight existing masonry towers located in the North-East of Italy. The towers, albeit unique for geometric and architectural features, show some affinities which justify a comparative analysis, as for instance the location and the similar masonry material. Their structural behavior under horizontal loads is therefore influenced by geometrical issues, such as slenderness, walls thickness, perforations, irregularities, presence of internal vaults, etc., all features which may be responsible for a peculiar output. The geometry of the towers is deduced from both existing available documentation and in-situ surveys. On the basis of such geometrical data, a detailed 3D realistic mesh is conceived, with a point by point characterization of each single geometric element. The FE models are analysed under seismic loads acting along geometric axes of the plan section, both under non-linear static (pushover) and non-linear dynamic excitation assumptions. A damage-plasticity material model exhibiting softening in both tension and compression, already available in the commercial code Abaqus, is used for masonry. Pushover analyses are performed with both G1 and G2 horizontal loads distribution, according to Italian code requirements, along X+/− and Y+/− directions. Non-linear dynamic analyses are performed along both X and Y directions with a real accelerogram scaled to different peak ground accelerations. Some few results are presented in this paper. It is found that the results obtained with pushover analyses reasonably well fit expensive non-linear dynamic simulations, with a slightly less conservative trend.

  14. 3D Numerical Simulation of the Geothermal Field of Permafrost at Salluit in Nunavik, Québec, in Response to Climate Warming. Research in Progress.

    Science.gov (United States)

    Fortier, R.; Allard, M.; Gagnon, O.

    2002-12-01

    survey aims at providing information on the geological and geotechnical characteristics of permafrost. Thermistor cables in deep boreholes, meteorological stations, dataloggers for the measurement of surface temperature, and thermal probes have been also installed in the valley. Air photographs will be used to produce a digital terrain model of the valley. This integrated multi-technique approach is essential for properly assessing the permafrost conditions in the valley. The study will provide the data needed for the development of a 3D model of permafrost conditions in the valley. A 3D numerical simulation of the geothermal field of permafrost in the valley will be then undertaken. This simulation is a major challenge giving the size of the thermal field and the variability in permafrost conditions. The impacts of climate warming on the thermal field of permafrost will be simulated and predicted by forcing the surface temperature to increase following different scenarios of climate warming. It is planned to combine the geotechnical properties and the simulation of the geothermal field of permafrost in order to define threshold values of permafrost strength and slope instability and set a pre-warning scheme of permafrost temperature in case of further warming in the coming years. The monitoring of permafrost temperature will be continued in the future. If the scheme is reached, actions can be then undertaken to mitigate the impacts of climate warming on the infrastructures and protect the population of Salluit.

  15. Analysis of the global free infra-gravity wave climate for the SWOT mission, and preliminary results of numerical modelling

    Science.gov (United States)

    Rawat, A.; Aucan, J.; Ardhuin, F.

    2012-12-01

    All sea level variations of the order of 1 cm at scales under 30 km are of great interest for the future Surface Water Ocean Topography (SWOT) satellite mission. That satellite should provide high-resolution maps of the sea surface height for analysis of meso to sub-mesoscale currents, but that will require a filtering of all gravity wave motions in the data. Free infragravity waves (FIGWs) are generated and radiate offshore when swells and/or wind seas and their associated bound infragravity waves impact exposed coastlines. Free infragravity waves have dominant periods comprised between 1 and 10 minutes and horizontal wavelengths of up to tens of kilometers. Given the length scales of the infragravity waves wavelength and amplitude, the infragravity wave field will can a significant fraction the signal measured by the future SWOT mission. In this study, we analyze the data from recovered bottom pressure recorders of the Deep-ocean Assessment and Reporting of Tsunami (DART) program. This analysis includes data spanning several years between 2006 and 2010, from stations at different latitudes in the North and South Pacific, the North Atlantic, the Gulf of Mexico and the Caribbean Sea. We present and discuss the following conclusions: (1) The amplitude of free infragravity waves can reach several centimeters, higher than the precision sought for the SWOT mission. (2) The free infragravity signal is higher in the Eastern North Pacific than in the Western North Pacific, possibly due to smaller incident swell and seas impacting the nearby coastlines. (3) Free infragravity waves are higher in the North Pacific than in the North Atlantic, possibly owing to different average continental shelves configurations in the two basins. (4) There is a clear seasonal cycle at the high latitudes North Atlantic and Pacific stations that is much less pronounced or absent at the tropical stations, consistent with the generation mechanism of free infragravity waves. Our numerical model

  16. Analysis and numerical modeling of the global free infra-gravity wave climate for the SWOT mission

    Science.gov (United States)

    Ardhuin, Fabrice; Aucan, Jérome; Rawat, Arshad

    2013-04-01

    All sea level variations of the order of 1 cm at scales under 30 km are of great interest for the future Surface Water Ocean Topography (SWOT) satellite mission. That satellite should provide high-resolution maps of the sea surface height for analysis of meso to sub-mesoscale currents, but that will require a filtering of all gravity wave motions in the data. Free infragravity waves (FIGWs) are generated and radiate offshore when swells and/or wind seas and their associated bound infragravity waves impact exposed coastlines. Free infragravity waves have dominant periods comprised between 1 and 10 minutes and horizontal wavelengths of up to tens of kilometers. Given the length scales of the infragravity waves wavelength and amplitude, the infragravity wave field will can a significant fraction the signal measured by the future SWOT mission. In this study, we analyze the data from recovered bottom pressure recorders of the Deep-ocean Assessment and Reporting of Tsunami (DART) program. This analysis includes data spanning several years between 2006 and 2010, from stations at different latitudes in the North and South Pacific, the North Atlantic, the Gulf of Mexico and the Caribbean Sea. We present and discuss the following conclusions: (1) The amplitude of free infragravity waves can reach several centimeters, higher than the precision sought for the SWOT mission. (2) The free infragravity signal is higher in the Eastern North Pacific than in the Western North Pacific, possibly due to smaller incident swell and seas impacting the nearby coastlines. (3) Free infragravity waves are higher in the North Pacific than in the North Atlantic, possibly owing to different average continental shelves configurations in the two basins. (4) There is a clear seasonal cycle at the high latitudes North Atlantic and Pacific stations that is much less pronounced or absent at the tropical stations, consistent with the generation mechanism of free infragravity waves. Our numerical model

  17. Localization and analysis of error sources for the numerical SIL proof; Lokalisierung und Analyse von Fehlerquellen beim numerischen SIL-Nachweis

    Energy Technology Data Exchange (ETDEWEB)

    Duepont, D.; Litz, L. [Technische Univ. Kaiserslautern (Germany). Lehrstuhl fuer Automatisierungstechnik; Netter, P. [Infraserv GmbH und Co. Hoechst KG, Frankfurt am Main (Germany)

    2008-07-01

    According to the standard IEC 61511 each safety-related loop is assigned to one of the four Safety Integrity Levels (SILs). For every safety-related loop a SIL-specific Probability of Failure on Demand (PFD) must be proven. Usually, the PFD calculation is performed based upon the failure rates of each loop component aided by commercial software tools. However, this bottom-up approach suffers from many uncertainties. Especially, a lack of reliable failure rate data causes many problems. Reference data collected in different environments are available to solve this situation. However, this pragmatism leads to a PFD bandwidth, not to a single PFD value as desired. In order to make a decision for a numerical value appropriate for the chemical and pharmaceutical process industry a data ascertainment has been initiated by the European NAMUR. Its results display large deficiencies for the bottom-up approach. The error sources leading to this situation are located and analyzed. (orig.)

  18. Experimental and numerical analyses of high voltage 4H-SiC junction barrier Schottky rectifiers with linearly graded field limiting ring

    Science.gov (United States)

    Wang, Xiang-Dong; Deng, Xiao-Chuan; Wang, Yong-Wei; Wang, Yong; Wen, Yi; Zhang, Bo

    2014-05-01

    This paper describes the successful fabrication of 4H-SiC junction barrier Schottky (JBS) rectifiers with a linearly graded field limiting ring (LG-FLR). Linearly variable ring spacings for the FLR termination are applied to improve the blocking voltage by reducing the peak surface electric field at the edge termination region, which acts like a variable lateral doping profile resulting in a gradual field distribution. The experimental results demonstrate a breakdown voltage of 5 kV at the reverse leakage current density of 2 mA/cm2 (about 80% of the theoretical value). Detailed numerical simulations show that the proposed termination structure provides a uniform electric field profile compared to the conventional FLR termination, which is responsible for 45% improvement in the reverse blocking voltage despite a 3.7% longer total termination length.

  19. Climate Physics

    Science.gov (United States)

    Space, William

    2007-01-01

    Numerous connections exist between climate science and topics normally covered in physics and physical science courses. For instance, lessons on heat and light can be used to introduce basic climate science, and the study of electric circuits provides a context for studying the relationship between electricity consumption and carbon pollution. To…

  20. Numerical study on the effects of aspect ratio and orientation of an urban street canyon on outdoor thermal comfort in hot and dry climate

    Energy Technology Data Exchange (ETDEWEB)

    Ali-Toudert, Fazia; Mayer, Helmut [Meteorological Institute, University of Freiburg,Werderring 10, D-79085 Freiburg (Germany)

    2006-02-01

    This paper discusses the contribution of street design, i.e. aspect ratio (or height-to-width ratio, H/W) and solar orientation, towards the development of a comfortable micro climate at street level for pedestrians. The investigation is carried out by using the three-dimensional numerical model ENVI-met, which simulates the microclimatic changes within urban environments in a high spatial and temporal resolution. Model calculations are run for a typical summer day in Ghardaia, Algeria (32.40{sup o}N, 3.80{sup o}E, 469ma.s.l.), a region characterized by a hot and dry climate. Symmetrical urban canyons, with various height-to-width ratios (i.e. H/W=0.5, 1, 2 and 4) and different solar orientations (i.e. E-W, N-S, NE-SW and NW-SE), have been studied. Special emphasis is placed on a human bio-meteorological assessment of these microclimates by using the physiologically equivalent temperature (PET). The results show contrasting patterns of thermal comfort between shallow and deep urban streets as well as between the various orientations studied. A comparison of all case studies reveals that the time and period of day during which extreme heat stress occurs, as well as the spatial distribution of PETs at street level, depend strongly on aspect ratio and street orientation. This is crucial since it will directly influence the design choices in relation to street usage, e.g. streets planned exclusively for pedestrian use or including motor traffic, and also the time of frequentation of urban spaces. Both investigated urban factors can mitigate extreme heat stress if appropriately combined. The solar access indoors has been briefly discussed as an additional criterion in designing the street by including winter needs for solar energy. (author)

  1. Pollen, biomes, forest successions and climate at Lake Barombi Mbo (Cameroon during the last ca. 33 000 cal yr BP – a numerical approach

    Directory of Open Access Journals (Sweden)

    J. Lebamba

    2010-12-01

    Full Text Available The aim of this paper is to provide a more complete and precise interpretation of the 33 000 cal yr BP pollen sequence from Lake Barombi Mbo, southwestern Cameroon (4°39'45.75'' N, 9°23'51.63'' E, 303 m a.s.l., based on a numerical approach allowing quantitative estimates of vegetation and climate. The biomisation method was applied on fossil pollen assemblages to reconstruct potential biomes and forest successional stages. The modern analogues (MAT and the artificial neural networks (ANN techniques were used to reconstruct mean annual rainfall (Pann, mean annual potential evapotranspiration (PETann and a bioclimatic index α related to the vegetation stature. Our reconstructions testifies of a dense forested environment around Lake Barombi Mbo of mixed evergreen/semi-deciduous type during the most humid phases (highest rainfall and lowest evapotranspiration reconstructed values, but with a more pronounced semi-deciduous facies from ca. 6500 cal yr BP to present day related to increased seasonality. These forests display a mature character until ca. 2800 cal yr BP then become of secondary type during the last millennium probably linked to increased human interferences. Two episodes of fragmentation are evidenced synchronous with the lowest rainfall and highest potential evapotranspiration reconstructed values, the first one centered during the LGM, and the second one from ca. 3000 to ca. 1200 cal yr BP linked mainly to high seasonality. But, as shown by low scores of savanna potential biome and successional stage, open formations never largely extend in the Barombi Mbo basin, and were more probably enclosed inside the forest in form of savanna patches. Concerning the climatic reconstructions at Lake Barombi Mbo, The ANN appears to be the most reliable technique in spite of under-estimated values of Pann all along the sequence mainly due to a lack of modern pollen data from very humid areas in central Africa.

  2. Investigating the sensitivity of numerical model simulations of the modern state of the Greenland ice-sheet and its future response to climate change

    Directory of Open Access Journals (Sweden)

    E. J. Stone

    2010-09-01

    Full Text Available Ice thickness and bedrock topography are essential boundary conditions for numerical modelling of the evolution of the Greenland ice-sheet (GrIS. The datasets currently in use by the majority of GrIS modelling studies are over two decades old and based on data collected from the 1970s and 80s. We use a newer, high-resolution Digital Elevation Model of the GrIS and new temperature and precipitation forcings to drive the Glimmer ice-sheet model offline under steady state, present day climatic conditions. Comparisons are made of ice-sheet geometry between these new datasets and older ones used in the EISMINT-3 exercise. We find that changing to the newer bedrock and ice thickness makes the greatest difference to Greenland ice volume and ice surface extent. When all boundary conditions and forcings are simultaneously changed to the newer datasets the ice-sheet is 33% larger in volume compared with observation and 17% larger than that modelled by EISMINT-3.

    We performed a tuning exercise to improve the modelled present day ice-sheet. Several solutions were chosen in order to represent improvement in different aspects of the GrIS geometry: ice thickness, ice volume and ice surface extent. We applied these new parameter sets for Glimmer to several future climate scenarios where atmospheric CO2 concentration was elevated to 400, 560 and 1120 ppmv (compared with 280 ppmv in the control using a fully coupled General Circulation Model. Collapse of the ice-sheet was found to occur between 400 and 560 ppmv, a threshold substantially lower than previously modelled using the standard EISMINT-3 setup. This work highlights the need to assess carefully boundary conditions and forcings required by ice-sheet models, particularly in terms of the abstractions required for large-scale ice-sheet models, and the implications that these can have on predictions of ice-sheet geometry under past and future climate scenarios.

  3. Numerical analyses of turbulence structure in rectangular ducts with rough and smooth walls. Applicability of simple analysis method using algebraic Reynolds stress model

    International Nuclear Information System (INIS)

    A numerical analysis has been performed for fully developed turbulent flow in a rectangular duct with smooth and rough walls by using algebraic Reynolds stress model. The wall functions and the universal law of the wall, which are used as the boundary conditions of turbulent energy and dissipation, apply in the present analysis instead of taking shape of roughness element into account. Therefore, the roughness enters through the log law relating the velocity at the first grid point away from the wall with the friction velocity. Two kinds of turbulent flows are examined, i.e., one is the turbulent flow in a rectangular duct with two roughened facing walls and the other is that flow in a rectangular duct with longitudinal ridges located lower and upper walls. These two kinds of calculated results are compared with experimental data each other. As for the comparison of rectangular duct with two roughened facing walls, the present calculated results show less distortion of streamwise velocity than the experimental data. This discrepancy may be attributable to assumption of the uniform roughness wall in calculation and separated flow observed in the experiment. On the other hand, calculated results of rectangular duct with ridges show a reasonable agreement in the streamwise velocity and the distributions of the Reynolds stresses. These examinations suggest the validity of the present method using the wall functions. (author)

  4. Experimental and numerical analyses on a plate heat exchanger with phase change for waste heat recovery at off-design conditions

    Science.gov (United States)

    Cipollone, Roberto; Bianchi, Giuseppe; Di Battista, Davide; Fatigati, Fabio

    2015-11-01

    This paper analyzes the performances of an evaporator for small scale waste heat recovery applications based on bottoming Organic Rankine Cycles with net output power in the range 2-5 kW. The heat recovery steam generator is a plate heat exchanger with oil as hot stream and an organic fluid on the cold side. An experimental characterization of the heat exchanger was carried out at different operating points measuring temperatures, pressures and flow rates on both sides. The measurement data further allowed to validate a numerical model of the evaporator whereas heat transfer coefficients were evaluated comparing several literature correlations, especially for the phase-change of the organic fluid. With reference to a waste heat recovery application in industrial compressed air systems, multiple off-design conditions were simulated considering the effects of oil mass flow rate and temperature on the superheating of the organic fluid, a key parameter to ensure a proper operation of the expansion machine, thus of the energy recovery process.

  5. Interdiffusion of the aluminum magnesium system. Quantitative analysis and numerical model; Interdiffusion des Aluminium-Magnesium-Systems. Quantitative Analyse und numerische Modellierung

    Energy Technology Data Exchange (ETDEWEB)

    Seperant, Florian

    2012-03-21

    Aluminum coatings are a promising approach to protect magnesium alloys against corrosion and thereby making them accessible to a variety of technical applications. Thermal treatment enhances the adhesion of the aluminium coating on magnesium by interdiffusion. For a deeper understanding of the diffusion process at the interface, a quantitative description of the Al-Mg system is necessary. On the basis of diffusion experiments with infinite reservoirs of aluminum and magnesium, the interdiffusion coefficients of the intermetallic phases of the Al-Mg-system are calculated with the Sauer-Freise method for the first time. To solve contradictions in the literature concerning the intrinsic diffusion coefficients, the possibility of a bifurcation of the Kirkendall plane is considered. Furthermore, a physico-chemical description of interdiffusion is provided to interpret the observed phase transitions. The developed numerical model is based on a temporally varied discretization of the space coordinate. It exhibits excellent quantitative agreement with the experimentally measured concentration profile. This confirms the validity of the obtained diffusion coefficients. Moreover, the Kirkendall shift in the Al-Mg system is simulated for the first time. Systems with thin aluminum coatings on magnesium also exhibit a good correlation between simulated and experimental concentration profiles. Thus, the diffusion coefficients are also valid for Al-coated systems. Hence, it is possible to derive parameters for a thermal treatment by simulation, resulting in an optimized modification of the magnesium surface for technical applications.

  6. Global sensitivity analysis of thermo-mechanical models in numerical weld modelling; Analyse de sensibilite globale de modeles thermomecaniques de simulation numerique du soudage

    Energy Technology Data Exchange (ETDEWEB)

    Petelet, M

    2007-10-15

    Current approach of most welding modellers is to content themselves with available material data, and to chose a mechanical model that seems to be appropriate. Among inputs, those controlling the material properties are one of the key problems of welding simulation: material data are never characterized over a sufficiently wide temperature range {exclamation_point} This way to proceed neglect the influence of the uncertainty of input data on the result given by the computer code. In this case, how to assess the credibility of prediction? This thesis represents a step in the direction of implementing an innovative approach in welding simulation in order to bring answers to this question, with an illustration on some concretes welding cases. The global sensitivity analysis is chosen to determine which material properties are the most sensitive in a numerical welding simulation and in which range of temperature. Using this methodology require some developments to sample and explore the input space covering welding of different steel materials. Finally, input data have been divided in two groups according to their influence on the output of the model (residual stress or distortion). In this work, complete methodology of the global sensitivity analysis has been successfully applied to welding simulation and lead to reduce the input space to the only important variables. Sensitivity analysis has provided answers to what can be considered as one of the probable frequently asked questions regarding welding simulation: for a given material which properties must be measured with a good accuracy and which ones can be simply extrapolated or taken from a similar material? (author)

  7. Numerical Simulation Study on the Impacts of Tropospheric O3 and CO2 Concentration Changes on Winter Wheat. Part Ⅱ:Simulation Results and Analyses

    Institute of Scientific and Technical Information of China (English)

    ZHENG Changling; WANG Chunyi

    2006-01-01

    With the rapid development of industrialization and urbanization, the enrichment of tropospheric ozone and carbon dioxide concentration at striking rates has caused effects on biosphere, especially on crops. It is generally accepted that the increase of CO2 concentration will have obverse effects on plant productivity while ozone is reported as the air pollutant most damaging to agricultural crops and other plants. The Model of Carbon and Nitrogen Biogeochemistry in Agroecosystems (DNDC) was adapted to evaluate simultaneously impacts of climate change on winter wheat.Growth development and yield formation of winter wheat under different Os and CO2 concentration conditions are simulated with the improved DNDC model whose structure has been described in another paper. Through adjusting the DNDC model applicability, winter wheat growth and development in Gucheng Station were simulated well in 1993 and 1999, which is in favor of modifying the model further. The model was validated against experiment observation, including development stage data, leaf area index, each organ biomass, and total aboveground biomass. Sensitivity tests demonstrated that the simulated results in development stage and biomass were sensitive to temperature change. The main conclusions of the paper are the following: 1) The growth and yield of winter wheat under CO2 concentration of 500 ppmv, 700 ppmv and the current ozone concentration are simulated respectively by the model. The results are well fitted with the observed data of OTCs experiments. The results show that increase of CO2 concentration may improve the growth of winter wheat and elevate the yield. 2) The growth and yield of winter wheat under O3 concentration of 50 ppbv, 100 ppbv, 200 ppbv and the based concentration CO2 are simulated respectively by the model. The simulated curves of stem, leaf, and spike organs growth as well as leaf area index are well accounted with the observed data. The results reveal that ozone has negative

  8. Climate change

    NARCIS (Netherlands)

    Marchal, V.; Dellink, R.; Vuuren, D.P. van; Clapp, C.; Chateau, J.; Magné, B.; Lanzi, E.; Vliet, J. van

    2012-01-01

    This chapter analyses the policy implications of the climate change challenge. Are current emission reduction pledges made in Copenhagen/Cancun enough to stabilise the climate and limit global average temperature increase to 2 oC? If not, what will the consequences be? What alternative growth pathwa

  9. Response of ice cover on shallow lakes of the North Slope of Alaska to contemporary climate conditions (1950–2011: radar remote sensing and numerical modeling data analysis

    Directory of Open Access Journals (Sweden)

    C. M. Surdu

    2013-07-01

    Full Text Available Air temperature and winter precipitation changes over the last five decades have impacted the timing, duration, and thickness of the ice cover on Arctic lakes as shown by recent studies. In the case of shallow tundra lakes, many of which are less than 3 m deep, warmer climate conditions could result in thinner ice covers and consequently, to a smaller fraction of lakes freezing to their bed in winter. However, these changes have not yet been comprehensively documented. The analysis of a 20 yr time series of ERS-1/2 synthetic aperture radar (SAR data and a numerical lake ice model were employed to determine the response of ice cover (thickness, freezing to the bed, and phenology on shallow lakes of the North Slope of Alaska (NSA to climate conditions over the last six decades. Analysis of available SAR data from 1991–2011, from a sub-region of the NSA near Barrow, shows a reduction in the fraction of lakes that freeze to the bed in late winter. This finding is in good agreement with the decrease in ice thickness simulated with the Canadian Lake Ice Model (CLIMo, a lower fraction of lakes frozen to the bed corresponding to a thinner ice cover. Observed changes of the ice cover show a trend toward increasing floating ice fractions from 1991 to 2011, with the greatest change occurring in April, when the grounded ice fraction declined by 22% (α = 0.01. Model results indicate a trend toward thinner ice covers by 18–22 cm (no-snow and 53% snow depth scenarios, α = 0.01 during the 1991–2011 period and by 21–38 cm (α = 0.001 from 1950–2011. The longer trend analysis (1950–2011 also shows a decrease in the ice cover duration by ∼24 days consequent to later freeze-up dates by 5.9 days (α = 0.1 and earlier break-up dates by 17.7–18.6 days (α = 0.001.

  10. Hydrogeologic influence on changes in snowmelt runoff with climate warming: Numerical experiments on a mid-elevation catchment in the Sierra Nevada, USA

    Science.gov (United States)

    Jepsen, S. M.; Harmon, T. C.; Meadows, M. W.; Hunsaker, C. T.

    2016-02-01

    The role of hydrogeology in mediating long-term changes in mountain streamflow, resulting from reduced snowfall in a potentially warmer climate, is currently not well understood. We explore this by simulating changes in stream discharge and evapotranspiration from a mid-elevation, 1-km2 catchment in the southern Sierra Nevada of California (USA) in response to reduced snowfall under warmer conditions, for a plausible range in subsurface hydrologic properties. Simulations are performed using a numerical watershed model, the Penn State Integrated Hydrologic Model (PIHM), constrained by observations from a meteorological station, stream gauge, and eddy covariance tower. We predict that the fraction of precipitation occurring as snowfall would decrease from approximately 47% at current conditions to 25%, 12%, and 5% for air temperature changes of +2, +4, and +6 °C. For each of these warming scenarios, changes in mean annual discharge and evapotranspiration simulated by the different plausible soil models show large ranges relative to averages, with coefficients of variation ranging from -3 to 3 depending on warming scenario. With warming and reduced snowfall, substrates with greater storage capacity show less soil moisture limitation on evapotranspiration during the late spring and summer, resulting in greater reductions in annual stream discharge. These findings indicate that the hydrologic response of mountain catchments to atmospheric warming and reduced snowfall may substantially vary across elevations with differing soil and regolith properties, a relationship not typically accounted for in approaches relying on space-for-time substitution. An additional implication of our results is that model simulations of annual stream discharge in response to snowfall-to-rainfall transitions may be relatively uncertain for study areas where subsurface properties are not well constrained.

  11. Dutch climate and energy policy. Analysis of policy reviews 1989-2012; Het Nederlandse Klimaat- en Energiebeleid. Analyse van beleidsevaluaties 1989-2012

    Energy Technology Data Exchange (ETDEWEB)

    Faber, J.; Blom, M.J.; De Bruyn, S.M.; Nelissen, D.; Aarnink, S.J.; De Buck, A.; Bennink, D. [CE Delft, Delft (Netherlands); Oosterhuis, F.H.; Kuik, O.J. [Instituut voor Milieuvraagstukken IVM, Vrije Universiteit VU, Amsterdam (Netherlands)

    2012-11-15

    The Dutch government has had climate policy in place since 1989. Since 1999 that policy has been intensified with a view to meeting Kyoto commitments for the period 2008-2012. The Dutch Parliament requested a review of the costs and effects of the measures implemented in the context of Dutch climate and energy policy, based on the available review studies, with led to the commissioning of the present report [Dutch] De Nederlandse overheid voert sinds 1989 klimaatbeleid. Vanaf 1999 is het beleid geïntensiveerd met het oog op het halen van de Kyoto-doelstelling in de periode 2008-2012. De Tweede Kamer wil een overzicht hebben van de kosten en effecten van beleidsinstrumenten van het Nederlandse klimaat- en energiebeleid, op basis van bestaande evaluatiestudies en heeft daarom deze studie laten uitvoeren.

  12. Biogas production in Oestfold. Analysis of climate utility and economy in a value chain perspective; Biogassproduksjon i Oestfold. Analyse av klimanytte og oekonomi i et verdikjedeperspektiv

    Energy Technology Data Exchange (ETDEWEB)

    Arnoey, Silje; Moeller, Hanne; Modahl, Ingunn Saur; Soerby, Ivar; Hanssen, Ole Joergen

    2013-03-01

    Waste management is an important issue. How we choose to deal with food waste that occurs, affects climate through emissions from all phases of waste management. One way of handling waste is to produce biogas from it. General results of the project 'the continuation of biogas model' has shown that the use of food waste as a substrate for biogas production in interaction with manure and great climate benefit. In order to assess the development of biogas production specifically for Oestfold, the general model was used for analysis with specific Oestfold data.The project's goal is that through the development of Oestfoldforskning's present climate and economic models will be carried out analyzes where these models will be tested with specific data of hypothetical case.These analyzes will form the basis for a strategic decision on the location and design of biogas plants in Oestfold. It should be noted that this report only will present greenhouse gas emissions, which represent an environmental indicator, and that the result of greenhouse gas emissions may not be directly transferable to other environmental indicators. Shortened version. (eb)

  13. Effects of technological progress and climate protection on electric power generation. Analyses using a General Equilibrium Model; Auswikungen des technologischen Fortschritts und des Klimaschutzes auf die Stromerzeugung. Analysen mit einem Allgemeinen Gleichgewichtsmodell

    Energy Technology Data Exchange (ETDEWEB)

    Zuern, Marcel

    2010-07-01

    The target of this thesis is the analysis of the connection between technological change and the development of global GHG with a quantitative analytic framework. Due to the special importance of the electricity generation sector for the mitigation of CO{sub 2} special attention is paid to this sector. The analysis of technological progress, particularly in the power generation sector on a global level, asks for substantial requirements of the analytic framework. The great number of actors and the interplay of interdependent factors make an analytical solution to the problem impossible. Therefore, a quantitative numerical model is necessary in order to analyse technological change on a global level. For the analysis of innovation and technological progress the sectoral, regional and chronological dimensions have to be considered explicitly: The analysis should take all economic areas into account because innovations are not restricted to a certain industrial sector or certain area of the economy but involve the whole economy. Concerning the geographical dimension innovations are not bound to a single country but spread out over national borders. Adjustments to technological development take time to unfold, and therefore an analytical framework should cover a long-term horizon. The same requirements apply to the regional, geographical and chronological dimensions when analysing measures to reduce GHG. The general equilibrium model used in this work (CGE - Computable General Equilibrium) fulfils all of the requirements listed above. Since the GHG problem is a global one, its analysis demands of model that is appropriate for this level. The structure of GHG models and the use of economic data on the global level allow for the correct methodology therefore. Since adjustments to measures of climate protection as well as innovations and technological change need time, a dynamic general equilibrium model with a long-term time horizon is used. Further advantages of CGE

  14. Statistical analyses for the purpose of an early detection of global and regional climate change due to the anthropogenic greenhouse effect; Statistische Analysen zur Frueherkennung globaler und regionaler Klimaaenderungen aufgrund des anthropogenen Treibhauseffektes

    Energy Technology Data Exchange (ETDEWEB)

    Grieser, J.; Staeger, T.; Schoenwiese, C.D.

    2000-03-01

    The report answers the question where, why and how different climate variables have changed within the last 100 years. The analyzed variables are observed time series of temperature (mean, maximum, minimum), precipitation, air pressure, and water vapour pressure in a monthly resolution. The time series are given as station data and grid box data as well. Two kinds of time-series analysis are performed. The first is applied to find significant changes concerning mean and variance of the time series. Thereby also changes in the annual cycle and frequency of extreme events arise. The second approach is used to detect significant spatio-temporal patterns in the variations of climate variables, which are most likely driven by known natural and anthropogenic climate forcings. Furtheron, an estimation of climate noise allows to indicate regions where certain climate variables have changed significantly due to the enhanced anthropogenic greenhouse effect. (orig.) [German] Der Bericht gibt Antwort auf die Frage, wo sich welche Klimavariable wie und warum veraendert hat. Ausgangspunkt der Analyse sind huntertjaehrige Zeitreihen der Temperatur (Mittel, Maximum, Minimum), des Niederschlags, Luftdrucks und Wasserdampfpartialdrucks in monatlicher Aufloesung. Es wurden sowohl Stationsdaten als auch Gitterpunktdaten verwendet. Mit Hilfe der strukturorientierten Zeitreihenzerlegung wurden signifikankte Aenderungen im Mittel und in der Varianz der Zeitreihen gefunden. Diese betreffen auch Aenderungen im Jahresgang und in der Haeufigkeit extremer Ereignisse. Die ursachenorientierte Zeitreihenzerlegung selektiert signifikante raumzeitliche Variationen der Klimavariablen, die natuerlichen bzw. anthropogenen Klimaantrieben zugeordnet werden koennen. Eine Abschaetzung des Klimarauschens erlaubt darueber hinaus anzugeben, wo und wie signifikant der anthropogene Treibhauseffekt welche Klimavariablen veraendert hat. (orig.)

  15. Analyses of surface and groundwater flow characteristics of the Ljubljana moor and water resources vulnerability to climate and land use change and groundwater overdraft

    Science.gov (United States)

    Globevnik, Lidija; Bracic Zeleznik, Branka

    2016-04-01

    One of the biggest water resource of Slovenian capital is groundwater of Ljubljana moor (Ljubljansko barje) aquifer. Quantity and quality of groundwater in Ljubljana moor aquifer directly depend on precipitation, surface water and riparian ecosystems of the Moor and indirectly by groundwater recharge from higher-lying mountainous karstic areas of forests and grasslands. Maintaining high groundwater level of the Ljubljana moor not only sustain stable water balance of aquifer, but also its riparian and wetland character. It also inhibit larger subsidence of the terrain. The paper addresses the vulnerability of the Ljubljana moor water resources to climate and land use change and due to groundwater overdraft. The results should help in selecting suitable mitigation measures and management of the Ljubljana moor area. We analyze surface and groundwater flow characteristics of water recharge area of one water work on the Ljubljana moor (Brest) from the point of view of climate change, changes in land use and water pumping practices. The I\\vska River, a tributary to the Ljubljanica River, recharges the area in the gravel bar, which lies just below the hills. We use existing data of meteorological, hydrological and hydrogeological monitoring and simulate rainfall-runoff processes. We use a conceptual semi-distributed rainfall-runoff model HBV-Light and simulate hydrological characteristics of the Ljubljana Moor (groundwater level fluctuations and recharge, surface - groundwater interchange) with two hydrodynamic models, DHI MIKE FLOOD (surface flow, 2D simulation) and DHI MIKE SHE (groundwater flow). For a calibration of runoff model HBV Light and MIKE SHE we use measured daily discharge data of the river I\\vska (1970-2010) and groundwater level data along the river (2010-2013) respectively. In groundwater modelling, we include the data of water pumping. Daily precipitation and temperature for period 2020 - 2050 are from ESAMBLE project for two GCM climate scenarios. We

  16. Bridging long proxy data time series and instrumental observation in the Virtual Institute of Integrated Climate and Landscape Evolution Analyses - ICLEA

    Science.gov (United States)

    Schwab, Markus J.; Brauer, Achim; Błaszkiewicz, Mirosław; Raab, Thomas; Wilmking, Martin

    2015-04-01

    Understanding causes and effects of present-day climate change on landscapes and the human habitat faces two main challenges, (i) too short time series of instrumental observation that do not cover the full range of variability since mechanisms of climate change and landscape evolution work on different time scales, which often not susceptible to human perception, and, (ii) distinct regional differences due to the location with respect to oceanic/continental climatic influences, the geological underground, and the history and intensity of anthropogenic land-use. Both challenges are central for the ICLEA research strategy and demand a high degree of interdisciplinary. In particular, the need to link observations and measurements of ongoing changes with information from the past taken from natural archives requires joint work of scientists with very different time perspectives. On the one hand, scientists that work at geological time scales of thousands and more years and, on the other hand, those observing and investigating recent processes at short time scales. The GFZ, Greifswald University and the Brandenburg University of Technology together with their partner the Polish Academy of Sciences strive for focusing their research capacities and expertise in ICLEA. ICLEA offers young researchers an interdisciplinary and structured education and promote their early independence through coaching and mentoring. Postdoctoral rotation positions at the ICLEA partner institutions ensure mobility of young researchers and promote dissemination of information and expertise between disciplines. Training, Research and Analytical workshops between research partners of the ICLEA virtual institute are another important measure to qualify young researchers. The long-term mission of the Virtual Institute is to provide a substantiated data basis for sustained environmental maintenance based on a profound process understanding at all relevant time scales. Aim is to explore processes of

  17. Analysing Italian Regional Patterns in Green Economy and Climate Change. Can Italy Leverage on Europe 2020 Strategy to Face Sustainable Growth Challenges ?

    Directory of Open Access Journals (Sweden)

    Francesco BONSINETTO

    2013-12-01

    Full Text Available European cities and regions are facing the crucial challenge of greening their economy towards more sustainable patterns. Politicians and policy-makers should promote new policies for sustainable growth including renewables, greenhouse gas emissions, energy efficiency and biodiversity. All of these aspects can be considered as a boost for local and regional economy. In this regard, European countries and regions can benefit from the Europe 2020 Strategy which is defined as Europe’s blueprint for a smart, sustainable and inclusive future, providing a ten year roadmap for growth and jobs. EU2020S was designed as a European exit strategy from the global economic and financial crisis in view of new European economic governance. This study discusses the above issues regarding Italy and intends to provide some answers on the perspectives of the new EU2020S. It draws from a research project supported by ESPON, the S.I.E.S.T.A. Project, focused on the territorial dimension of the EU2020S. Therefore, this paper aims at analyzing Italian regional patterns on climate change, green economy and energy within the context of EU2020S and at providing policy recommendations for better achieving the goals of the Strategy.

  18. Development and application of a numerical simulation system to evaluate the impact of anthropogenic heat fluxes on urban boundary layer climate

    OpenAIRE

    Krpo, Andrea

    2009-01-01

    Increasing economic development, and growing population, generated during the last decades a very important growth of cities. Urban regions include nowadays more than half of the global population and, by 2030, this proportion is forecasted to increase to three quarters. A consequent more and more extensive use of natural resources, together with increasing anthropogenic activities such as emissions from traffic and factories, or heating from air-conditioning facilities, modify local climate ...

  19. Climate change: a primer

    OpenAIRE

    Khanna, Dr. Perminder; Aneja, Reenu

    2011-01-01

    Abstract Climate has inherent variability manifesting in gradual changes in temperature, precipitation and sea-level rise. The paper entitled “Climate Change: A Primer” attempts to analyse the policy response and adaptation to the need to address climate change at the international and domestic level both. Intense variations in climate would increase the risk of abrupt and non-linear changes in the ecosystem, impacting their function, biodiversity and productivity. The policy initiations and ...

  20. Analysing EWviews

    DEFF Research Database (Denmark)

    Jelsøe, Erling; Jæger, Birgit

    2015-01-01

    When analysing the results of a European wide citizen consultation on sustainable consumption it is necessary to take a number of issues into account, such as the question of representativity and tensions between national and European identies and between consumer and Citizen orientations regarding...

  1. Reconstructing the response of C3 and C4 plants to decadal-scale climate change during the late Pleistocene in southern Illinois using isotopic analyses of calcified rootlets

    Science.gov (United States)

    Wang, Hongfang; Greenberg, S.E.

    2007-01-01

    The ??13C and ??18O values of well-preserved carbonate rhizoliths (CRs) provide detailed insights into changes in the abundance of C3 and C4 plants in response to approximately decadal-scale changes in growing-season climate. We performed stable isotope analyses on 35-40 CRs sampled at 1-cm intervals from an 18-cm-thick paleosol formed in southern Illinois during Wisconsin interstadial 2. Minimum ??13C values show little variation with depth, whereas maximum values vary dramatically, and average values show noticeable variability; maximum ??18O values vary less than the minimum ??18O values. These findings indicate that a diverse and stable C3 flora with a limited number of C4 grass species prevailed during this interval, and suggest that the maximum growing-season temperatures were relatively stable, but minimum growing-season temperatures varied considerably. Two general patterns characterize the relationships between the ??13C and ??18O values obtained from the 1-cm samples. In some cases, low ??13C values correspond to low ??18O values and high ??13C values correspond to high ??18O values, suggesting that cooler growing-season temperatures favored C3 and warmer growing-season temperatures favored C4 plants. In other cases, low ??13C values correspond to high ??18O values, likely suggesting that wetter growing-season conditions were favorable to C3 plants. The high density of well-preserved CRs in this paleosol provides a unique opportunity to study detailed ecological responses to high-resolution variability in growing-season climate. ?? 2006 University of Washington.

  2. Numerical modeling of the Snowmass Creek paleoglacier, Colorado, and climate in the Rocky Mountains during the Bull Lake glaciation (MIS 6)

    Energy Technology Data Exchange (ETDEWEB)

    Eric M. Leonard; Mitchell A. Plummer; Paul E. Carrara

    2014-04-01

    Well-preserved moraines from the penultimate, or Bull Lake, glaciation of Snowmass Creek Valley in the Elk Range of Colorado present an opportunity to examine the character of the high-altitude climate in the Rocky Mountains during Marine Oxygen Isotope Stage 6. This study employs a 2-D coupled mass/energy balance and flow model to assess the magnitudes of temperature and precipitation change that could have sustained the glacier in mass-balance equilibrium at its maximum extent during the Bull Lake glaciation. Variable substrate effects on glacier flow and ice thickness make the modeling somewhat more complex than in geologically simpler settings. Model results indicate that a temperature depression of about 6.7°C compared with the present (1971–2000 AD) would have been necessary to sustain the Snowmass Creek glacier in mass-balance equilibrium during the Bull Lake glaciation, assuming no change in precipitation amount or seasonality. A 50% increase or decrease from modern precipitation would have been coupled with 5.2°C and 9.1°C Bull Lake temperature depressions respectively. Uncertainty in these modeled temperature depressions is about 1°C.

  3. AMS analyses at ANSTO

    Energy Technology Data Exchange (ETDEWEB)

    Lawson, E.M. [Australian Nuclear Science and Technology Organisation, Lucas Heights, NSW (Australia). Physics Division

    1998-03-01

    The major use of ANTARES is Accelerator Mass Spectrometry (AMS) with {sup 14}C being the most commonly analysed radioisotope - presently about 35 % of the available beam time on ANTARES is used for {sup 14}C measurements. The accelerator measurements are supported by, and dependent on, a strong sample preparation section. The ANTARES AMS facility supports a wide range of investigations into fields such as global climate change, ice cores, oceanography, dendrochronology, anthropology, and classical and Australian archaeology. Described here are some examples of the ways in which AMS has been applied to support research into the archaeology, prehistory and culture of this continent`s indigenous Aboriginal peoples. (author)

  4. AMS analyses at ANSTO

    International Nuclear Information System (INIS)

    The major use of ANTARES is Accelerator Mass Spectrometry (AMS) with 14C being the most commonly analysed radioisotope - presently about 35 % of the available beam time on ANTARES is used for 14C measurements. The accelerator measurements are supported by, and dependent on, a strong sample preparation section. The ANTARES AMS facility supports a wide range of investigations into fields such as global climate change, ice cores, oceanography, dendrochronology, anthropology, and classical and Australian archaeology. Described here are some examples of the ways in which AMS has been applied to support research into the archaeology, prehistory and culture of this continent's indigenous Aboriginal peoples. (author)

  5. Numerical analysis

    CERN Document Server

    Khabaza, I M

    1960-01-01

    Numerical Analysis is an elementary introduction to numerical analysis, its applications, limitations, and pitfalls. Methods suitable for digital computers are emphasized, but some desk computations are also described. Topics covered range from the use of digital computers in numerical work to errors in computations using desk machines, finite difference methods, and numerical solution of ordinary differential equations. This book is comprised of eight chapters and begins with an overview of the importance of digital computers in numerical analysis, followed by a discussion on errors in comput

  6. Island shadow effects and the wave climate of the Western Tuamotu Archipelago (French Polynesia) inferred from altimetry and numerical model data.

    Science.gov (United States)

    Andréfouët, Serge; Ardhuin, Fabrice; Queffeulou, Pierre; Le Gendre, Romain

    2012-01-01

    To implement a numerical model of atoll lagoon circulation, we characterized first the significant wave height (Hs) regime of the Western Tuamotu Archipelago and the local attenuation due to the protection offered by large atolls in the south Tuamotu. Altimetry satellite data and a WAVEWATCH III two-way nested wave model at 5 km resolution from 2000 to 2010 were used. Correlation between altimetry and model was high (0.88) over the period. According to the wave model, the archipelago inner seas experienced attenuated Hs year-long with a yearly average Hs around 1.3m vs a minimum of 1.6m elsewhere. The island shadow effect is especially significant in the austral winter. In contrast with southern atolls, Western Tuamotu experienced only few days per year of Hs larger than 2.5m generated by very high Hs southern swell, transient western local storms, strong easterly winds, and during the passage of distant hurricanes. PMID:22795488

  7. Reliance, liance et alliance : opérationnalité des concepts dans l'analyse du climat socio-relationnel de groupes restreints d'apprentissage en ligne

    Directory of Open Access Journals (Sweden)

    Jean-Jacques Quintin

    2010-10-01

    Full Text Available La recherche que nous présentons ici se donne pour but de mesurer le lien entre le "climat socio-relationnel" d'un groupe restreint engagé dans un travail collaboratif en ligne et la qualité des travaux collectifs produits. La démarche méthodologique adoptée, basée sur une analyse des échanges asynchrones entre les membres d'un groupe, nous permet d'aboutir à un modèle opératoire qui fait état des composantes du "climat socio-relationnel" susceptibles d'expliquer les résultats d'apprentissage obtenus. Deux notions – dérivées du concept sociologique de reliance – seront mobilisées : la liance et l'alliance. La première rend compte de la qualité de la relation (la chaleur, l'intimité, les émotions… qui se crée entre les interlocuteurs au cours de leurs échanges asynchrones. La seconde traduit la manière dont les participants confortent leur contrat d'association en vue de la réalisation du travail commun, afin de répondre aux exigences pédagogiques fixées. Les résultats de cette recherche montrent que, dans notre situation d'étude, le modèle de la reliance explique une part substantielle de la qualité moyenne des produits de l'apprentissage collectif et possède une homogénéité interne non négligeable. Ces éléments concourent à étayer l'assise conceptuelle et le caractère opératoire du modèle présenté.The aim of the research we are presenting here is to measure the link between the "socio-relational climate" of a small group in a collaborative work environment and the quality of the collective work they provide. The methodological approach adopted, based on an analysis of the asynchronous exchanges between members of a group, allows us to find a procedure that takes stock of some components of "socio-relational climate" that could account for the results in terms of learning. Two notions – derivatives of the sociological concept "reliance" – will be called upon: "liance" and "alliance". The

  8. Expert judgement and uncertainty quantification for climate change

    Science.gov (United States)

    Oppenheimer, Michael; Little, Christopher M.; Cooke, Roger M.

    2016-05-01

    Expert judgement is an unavoidable element of the process-based numerical models used for climate change projections, and the statistical approaches used to characterize uncertainty across model ensembles. Here, we highlight the need for formalized approaches to unifying numerical modelling with expert judgement in order to facilitate characterization of uncertainty in a reproducible, consistent and transparent fashion. As an example, we use probabilistic inversion, a well-established technique used in many other applications outside of climate change, to fuse two recent analyses of twenty-first century Antarctic ice loss. Probabilistic inversion is but one of many possible approaches to formalizing the role of expert judgement, and the Antarctic ice sheet is only one possible climate-related application. We recommend indicators or signposts that characterize successful science-based uncertainty quantification.

  9. 宁夏近百年来的气候变化及突变分析%Period and Jump Analyses of Climatic Variation in Ningxia in Recent Hundred Years

    Institute of Scientific and Technical Information of China (English)

    李艳春; 李艳芳

    2001-01-01

    Using Mann-Kendall jump test and moving t test, the periods andjump character of climatic variation in Ningxia in recent century are analysed based on the data of annual rainfall and temperature departure during recent hundred years in north of Ningxia and the data of temperature and precipitation obtained from 19 meterological stations of Ningxia since using apparatus. The results show that the climate in Ningxia during recent century can be divided into 5 main periods. Before 1930's, it was a dry and cold period; from 1930's to the middle 1950's, a warm and humid period; from the middle 1950's to the late 1960's, a cold and humid period; from the late 1960's to the middle 1980's, a cold and dry period, and from the middle 1980's to now, a warm and dry period. The annual mean temperature as well as autumn and winter temperature became jump in the middle 1980's. About 1960's, the annual precipitation became jump and in the middle and late 1970's, the autumn precipitation of Ningxia became jump.%以宁夏北部地区近百年来的年降水量、气温距平资料以及全区各季有仪器观测以来的温度降水资料为基础,利用Mann-Kendall突变检验法和滑动t检验法,分析了宁夏近百年来气候变化的阶段性和突变特点。结果表明:近百年来宁夏气候大概经历了五个主要阶段;80年代中期年平均气温及秋冬季平均气温发生突变;60年代左右年降水量发生突变;70年代中后期全区秋季降水量出现突变。

  10. Numerical taxonomy

    OpenAIRE

    Inger, Robert F.

    2012-01-01

    For some strange reason the attitudes of taxonomists and systematists towards the phrase "numerical taxonomy" fall into two extreme positions. On the one hand are those who think numerical taxonomy provides the only means of reaching objective conclusions, that any other approach to taxonomy is sterile, subjective, and really not quite scientific. At the other extreme are those taxonomists who think numerical taxonomy has no place in their science, that it is unclean or is likely to be ...

  11. On the Sensitivity of L/E Analysis of Super-Kamiokande Atmospheric Neutrino Data to Neutrino Oscillation Part~2 --- Four Possible L/E Analyses for the Maximum Oscillation by the Numerical Computer Experiment ---

    OpenAIRE

    Konishi, E; Minorikawa, Y.; Galkin, V. I.; Ishiwata, M.; Nakamura, I.; Takahashi, N; Kato, M.; Misaki, A.

    2010-01-01

    In the previous paper (Part~1), we have verified that the SK assumption on the direction does not hold in the analysis of neutrino events occurred inside the SK detector. We have made four possible L/E analyses, L_nu/E_nu, L_nu/E_mu, L_mu/E_nu and L_mu/E_mu. Among four kinds of L/E analyses, we have shown that only L_nu/E_nu analysis can give the signature of maximum oscillations clearly, while the L_mu/E_mu analysis which are really done by Super-Kamiokande Collaboration cannot give the maxi...

  12. Numerical analysis targets

    International Nuclear Information System (INIS)

    Numerical analyses are needed in different steps of the overall design process. Complex models or non-linear reactor core behaviour are important for qualification and/or comparison of results obtained. Adequate models and test should be defined. Fuel assembly, fuel row, and the complete core should be tested for seismic effects causing LOCA and flow-induced vibrations (FIV)

  13. Groundwater flow dynamics of weathered hard-rock aquifers under climate-change conditions: an illustrative example of numerical modeling through the equivalent porous media approach in the north-western Pyrenees (France)

    Science.gov (United States)

    Jaunat, J.; Dupuy, A.; Huneau, F.; Celle-Jeanton, H.; Le Coustumer, P.

    2016-04-01

    A numerical groundwater model of the weathered crystalline aquifer of Ursuya (a major water source for the north-western Pyrenees region, south-western France) has been computed based on monitoring of hydrological, hydrodynamic and meteorological parameters over 3 years. The equivalent porous media model was used to simulate groundwater flow in the different layers of the weathered profile: from surface to depth, the weathered layer (5 · 10-8 ≤ K ≤ 5 · 10-7 m s-1), the transition layer (7 · 10-8 ≤ K ≤ 1 · 10-5 m s-1, the highest values being along major discontinuities), two fissured layers (3.5 · 10-8 ≤ K ≤ 5 · 10-4 m s-1, depending on weathering profile conditions and on the existence of active fractures), and the hard-rock basement simulated with a negligible hydraulic conductivity (K = 1 10 -9 ). Hydrodynamic properties of these five calculation layers demonstrate both the impact of the weathering degree and of the discontinuities on the groundwater flow. The great agreement between simulated and observed hydraulic conditions allowed for validation of the methodology and its proposed use for application on analogous aquifers. With the aim of long-term management of this strategic aquifer, the model was then used to evaluate the impact of climate change on the groundwater resource. The simulations performed according to the most pessimistic climatic scenario until 2050 show a low sensitivity of the aquifer. The decreasing trend of the natural discharge is estimated at about -360 m3 y-1 for recharge decreasing at about -5.6 mm y-1 (0.8 % of annual recharge).

  14. Numerical Development

    Science.gov (United States)

    Siegler, Robert S.; Braithwaite, David W.

    2016-01-01

    In this review, we attempt to integrate two crucial aspects of numerical development: learning the magnitudes of individual numbers and learning arithmetic. Numerical magnitude development involves gaining increasingly precise knowledge of increasing ranges and types of numbers: from non-symbolic to small symbolic numbers, from smaller to larger…

  15. LHS (latin hypercubes) sampling of the material properties of steels for the analysis of the global sensitivity in welding numerical simulation; Echantillonnage LHS des proprietes materiau des aciers pour l analyse de sensibilite globale en simulation numerique du soudage

    Energy Technology Data Exchange (ETDEWEB)

    Petelet, Matthieu; Asserin, Olivier [CEA, DRT / LITEN / DTH / LTA, Bat 611, 91191 Gif sur Yvette Cedex (France); Iooss, Bertrand [CEA, DEN / CAD / DER / SESI / LCFR, Bat 212, 13108 St-Paul-lez-Durance Cedex (France); Petelet, Matthieu; Loredo, Alexandre [ISAT / LRMA, 49 rue Melle Bourgeois, BP 31, 58027 Nevers Cedex (France)

    2006-07-01

    In this work, the method of sensitivity analysis allowing to identify the inlet data the most influential on the variability of the responses (residual stresses and distortions). Classically, the sensitivity analysis is carried out locally what limits its validity domain to a given material. A global sensitivity analysis method is proposed; it allows to cover a material domain as wide as those of the steels series. A probabilistic modeling giving the variability of the material parameters in the steels series is proposed. The original aspect of this work consists in the use of the sampling method by latin hypercubes (LHS) of the material parameters which forms the inlet data (dependent of temperature) of the numerical simulations. Thus, a statistical approach has been applied to the welding numerical simulation: LHS sampling of the material properties, global sensitivity analysis what has allowed the reduction of the material parameterization. (O.M.)

  16. Validation of two high‐resolution climate simulations over Scandinavia

    DEFF Research Database (Denmark)

    Mayer, Stephanie; Maule, Cathrine Fox; Sobolowski, Stefan;

    2014-01-01

    Before running climate projections with numerical models it is important to validate their performance under present climate conditions. Within the RiskChange project two high‐resolution regional climate models were run as a perfect boundary experiment over Scandinavia. The simulations are...... study is to analyse the properties of high‐resolution climate simulations over Scandinavia by testing a hypothesis that dynamic simulations are better at retaining the properties of precipitation, notably precipitation extremes than coarser simulations. When compared to statistical methods the dynamical...... downscaling has the advantage of retaining the full set of atmospheric variables as well as a physically more realistic description of e.g. complex terrain (e.g. mountain ranges and coastlines) and when the representation and behaviour of extremes are important to be captured in a realistic manner. Here, we...

  17. On the Sensitivity of L/E Analysis of Super-Kamiokande Atmospheric Neutrino Data to Neutrino Oscillation Part~2 --- Four Possible L/E Analyses for the Maximum Oscillation by the Numerical Computer Experiment ---

    CERN Document Server

    Konishi, E; Galkin, V I; Ishiwata, M; Nakamura, I; Takahashi, N; Kato, M; Misaki, A

    2010-01-01

    In the previous paper (Part~1), we have verified that the SK assumption on the direction does not hold in the analysis of neutrino events occurred inside the SK detector. We have made four possible L/E analyses, L_nu/E_nu, L_nu/E_mu, L_mu/E_nu and L_mu/E_mu. Among four kinds of L/E analyses, we have shown that only L_nu/E_nu analysis can give the signature of maximum oscillations clearly, while the L_mu/E_mu analysis which are really done by Super-Kamiokande Collaboration cannot give the maximum oscillation at all. It is thus concluded that Super-Kamiokande type experiment cannot find the maximum oscillation from L/E analysis. Therefore, we would suggest Super-Kamiokande Collaboration to re-analyze the zenith angle distribution of the neutrino events which occur inside the detector carefully.

  18. Mathematical and numerical analysis of a multi-velocity multi-fluid model for interpenetration of miscible fluids; Analyse mathematique et numerique d'un modele multifluide multivitesse pour l'interpenetration de fluides miscibles

    Energy Technology Data Exchange (ETDEWEB)

    Enaux, C

    2007-11-15

    The simulation of indirect laser implosion requires an accurate knowledge of the inter-penetration of the laser target materials turned into plasma. This work is devoted to the study of a multi-velocity multi-fluid model recently proposed by Scannapieco and Cheng (SC) to describe the inter-penetration of miscible fluids. In this document, we begin with presenting the SC model in the context of miscible fluids flow modelling. Afterwards, the mathematical analysis of the model is carried out (study of the hyperbolicity, existence of a strictly convex mathematical entropy, asymptotic analysis and diffusion limit). As a conclusion the problem is well set. Then, we focus on the problem of numerical resolution of systems of conservation laws with a relaxation source term, because SC model belongs to this class. The main difficulty of this task is to capture on a coarse grid the asymptotic behaviour of the system when the source term is stiff. The main contribution of this work lies in the proposition of a new technique, allowing us to construct a Lagrangian numerical flux taking into account the presence of the source term. This technique is applied first on the model-problem of a one-dimensional Euler system with friction, and then on the multi-fluid SC model. In both cases, we prove that the new scheme is asymptotic-preserving and entropic under a CFL-like condition. The two-dimensional extension of the scheme is done by using a standard alternate directions method. Some numerical results highlight the contribution of the new flux, compared with a standard Lagrange plus Remap scheme where the source term is processed using an operator splitting. (author)

  19. Numerical analysis

    CERN Document Server

    Scott, L Ridgway

    2011-01-01

    Computational science is fundamentally changing how technological questions are addressed. The design of aircraft, automobiles, and even racing sailboats is now done by computational simulation. The mathematical foundation of this new approach is numerical analysis, which studies algorithms for computing expressions defined with real numbers. Emphasizing the theory behind the computation, this book provides a rigorous and self-contained introduction to numerical analysis and presents the advanced mathematics that underpin industrial software, including complete details that are missing from m

  20. Application de la teledetection a l'analyse de la variabilite climatique des regions boreales et subarctiques du Canada et a la validation du modele regional canadien du climat

    Science.gov (United States)

    Fillol, Erwann Joachim

    The subject of the present thesis fits within the scope of global climate change analysis. It focuses on two main areas of interest, namely the study of recent past climate over the last few decades and the development of tools for modeling future climate. Study of past climate. The first part of this thesis deals with the interpretation of NOAA-AVHRR (National Oceanic and Atmospheric Administration - Advanced Very High Resolution Radiometer) time series at the continental spatial scale. The data constitute an archive of decadal or weekly composite spanning over two decades which was developed for studying and monitoring boreal ecosystem activity in Canada. This study uses classical parameters derived from remote sensing in the visible and thermal infrared spectra (NDVI vegetation activity index, land-surface temperature Ts), as well as indicators chosen for their robustness. The latter parameters (length of the growing season, annual growing degree-days, and ecotone displacement) were selected so as to minimize problems related to instrumental drift and inter-satellite adjustment. The study of the twenty year NOAA-AVHRR satellite archives, permitted the observation of recent climate variations. There were compared with daily meteorological surveys of temperature and precipitation as well as with the length of the snow cover period. It was possible to observe rapid cycle climatic phenomena such as the El Nino/La Nina couple whose effect on surface temperature and the length of the growing season was found to be more significant over the central region of Canada. The NAO (North Atlantic Oscillation) and AO (Arctic Oscillation) oscillations were also found to have an influence on the climatic regime of Canada. The effects of these climatic cycles on the annual growing degree-days are more accentuated over the Northeastern region of Canada in spring. Significant climatic trends over the last twenty years were also observed. We demonstrated, based on the use of the

  1. Uncertainty assessment tool for climate change impact indicators

    Science.gov (United States)

    Otto, Juliane; Keup-Thiel, Elke; Jacob, Daniela; Rechid, Diana; Lückenkötter, Johannes; Juckes, Martin

    2015-04-01

    A major difficulty in the study of climate change impact indicators is dealing with the numerous sources of uncertainties of climate and non-climate data . Its assessment, however, is needed to communicate to users the degree of certainty of climate change impact indicators. This communication of uncertainty is an important component of the FP7 project "Climate Information Portal for Copernicus" (CLIPC). CLIPC is developing a portal to provide a central point of access for authoritative scientific information on climate change. In this project the Climate Service Center 2.0 is in charge of the development of a tool to assess the uncertainty of climate change impact indicators. The calculation of climate change impact indicators will include climate data from satellite and in-situ observations, climate models and re-analyses, and non-climate data. There is a lack of a systematic classification of uncertainties arising from the whole range of climate change impact indicators. We develop a framework that intends to clarify the potential sources of uncertainty of a given indicator and provides - if possible - solutions how to quantify the uncertainties. To structure the sources of uncertainties of climate change impact indicators, we first classify uncertainties along a 'cascade of uncertainty' (Reyer 2013). Our cascade consists of three levels which correspond to the CLIPC meta-classification of impact indicators: Tier-1 indicators are intended to give information on the climate system. Tier-2 indicators attempt to quantify the impacts of climate change on biophysical systems (i.e. flood risks). Tier-3 indicators primarily aim at providing information on the socio-economic systems affected by climate change. At each level, the potential sources of uncertainty of the input data sets and its processing will be discussed. Reference: Reyer, C. (2013): The cascade of uncertainty in modeling forest ecosystem responses to environmental change and the challenge of sustainable

  2. Numerical analysis

    CERN Document Server

    Brezinski, C

    2012-01-01

    Numerical analysis has witnessed many significant developments in the 20th century. This book brings together 16 papers dealing with historical developments, survey papers and papers on recent trends in selected areas of numerical analysis, such as: approximation and interpolation, solution of linear systems and eigenvalue problems, iterative methods, quadrature rules, solution of ordinary-, partial- and integral equations. The papers are reprinted from the 7-volume project of the Journal of Computational and Applied Mathematics on '/homepage/sac/cam/na2000/index.html<

  3. Phytoplankton and Climate

    Science.gov (United States)

    Moisan, John R.

    2009-01-01

    Ocean phytoplankton supply about half of the oxygen that humans utilize to sustain life. In this lecture, we will explore how phytoplankton plays a critical role in modulating the Earth's climate. These tiny organisms are the base of the Ocean's food web. They can modulate the rate at which solar heat is absorbed by the ocean, either through direct absorption or through production of highly scattering cellular coverings. They take up and help sequester carbon dioxide, a key greenhouse gas that modulated the Earth's climate. They are the source of cloud nucleation gases that are key to cloud formation/processes. They are also able to modify the nutrient budgets of the ocean through active uptake of inert atmospheric nitrogen. Climate variations have a pronounced impact on phytoplankton dynamics. Long term variations in the climate have been studied through geological interpretations on its influence on phytoplankton populations. The presentation will focus on presenting the numerous linkages that have been observed between climate and phytoplankton and further discuss how present climate change scenarios are likely to impact phytoplankton populations as well as present findings from several studies that have tried to understand how the climate might react to the feedbacks from these numerous climate-phytop|ankton linkages.

  4. Numerical Relativity

    Science.gov (United States)

    Baker, John G.

    2009-01-01

    Recent advances in numerical relativity have fueled an explosion of progress in understanding the predictions of Einstein's theory of gravity, General Relativity, for the strong field dynamics, the gravitational radiation wave forms, and consequently the state of the remnant produced from the merger of compact binary objects. I will review recent results from the field, focusing on mergers of two black holes.

  5. Numerical Methods

    OpenAIRE

    Dusan Maga

    2004-01-01

    Presented paper is based on authors experience on numerical methods of field solution, mostly magnetic. This paper, as the first one of prepared series, deals with mathematical apparatus and basic physical principles, as well as with possible short-comings or advantages when using the Finite Difference Method (FDM).

  6. The CCPP-ARM Parameterization Testbed (CAPT): Where Climate Simulation Meets Weather Prediction

    Energy Technology Data Exchange (ETDEWEB)

    Phillips, T J; Potter, G L; Williamson, D L; Cederwall, R T; Boyle, J S; Fiorino, M; Hnilo, J J; Olson, J G; Xie, S; Yio, J J

    2003-11-21

    To significantly improve the simulation of climate by general circulation models (GCMs), systematic errors in representations of relevant processes must first be identified, and then reduced. This endeavor demands, in particular, that the GCM parameterizations of unresolved processes should be tested over a wide range of time scales, not just in climate simulations. Thus, a numerical weather prediction (NWP) methodology for evaluating model parameterizations and gaining insights into their behavior may prove useful, provied that suitable adaptations are made for implementation in climate GCMs. This method entails the generation of short-range weather forecasts by realistically initialized climate GCM, and the application of six-hourly NWP analyses and observations of parameterized variables to evaluate these forecasts. The behavior of the parameterizations in such a weather-forecasting framework can provide insights on how these schemes might be improved, and modified parameterizations then can be similarly tested. In order to further this method for evaluating and analyzing parameterizations in climate GCMs, the USDOE is funding a joint venture of its Climate Change Prediction Program (CCPP) and Atmospheric Radiation Measurement (ARM) Program: the CCPP-ARM Parameterization Testbed (CAPT). This article elaborates the scientific rationale for CAPT, discusses technical aspects of its methodology, and presents examples of its implementation in a representative climate GCM. Numerical weather prediction methods show promise for improving parameterizations in climate GCMs.

  7. From Richardson to early numerical weather prediction

    OpenAIRE

    Lynch, Peter

    2010-01-01

    The development of computer models for numerical simulation of the atmosphere and oceans is one of the great scientific triumphs of the past fifty years. These models have added enormously to our understanding of the complex processes in the atmosphere and oceans. The consequences for humankind of ongoing climate change will be far-reaching. Earth system models are the best means we have of predicting the future of our climate. The basic ideas of numerical forecasting and c...

  8. Numerical analysis of resonances induced by s wave neutrons in transmission time-of-flight experiments with a computer IBM 7094 II; Methodes d'analyse des resonances induites par les neutrons s dans les experiences de transmission par temps de vol et automatisation de ces methodes sur ordinateur IBM 7094 II

    Energy Technology Data Exchange (ETDEWEB)

    Corge, Ch. [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

    1969-01-01

    Numerical analysis of transmission resonances induced by s wave neutrons in time-of-flight experiments can be achieved in a fairly automatic way on an IBM 7094/II computer. The involved computations are carried out following a four step scheme: 1 - experimental raw data are processed to obtain the resonant transmissions, 2 - values of experimental quantities for each resonance are derived from the above transmissions, 3 - resonance parameters are determined using a least square method to solve the over determined system obtained by equalling theoretical functions to the correspondent experimental values. Four analysis methods are gathered in the same code, 4 - graphical control of the results is performed. (author) [French] L'automatisation, sur ordinateur IBM 7094/II, de l'analyse des resonances induites par les neutrons s dans les experiences de transmission par temps de vol a ete accomplie en la decomposant selon un schema articule en quatre phases: 1 - le traitement des donnees experimentales brutes pour obtenir les transmissions interfero-resonnantes, 2 - la determination des grandeurs d'analyse a partir des transmissions precedentes, 3 - l'analyse proprement dite des resonances dont les parametres sont obtenus par la resolution d'un systeme surabondant. Quatre methodes d'analyse sont groupees en un meme programme, 4 - la procedure de verification graphique. (auteur)

  9. Climate science: Misconceptions of global catastrophe

    Science.gov (United States)

    Rocklöv, Joacim

    2016-04-01

    American attitudes to changing weather, and therefore to climate change, have been analysed on the basis of US migration patterns since the 1970s. The findings have implications for the success of global climate policies. See Letter p.357

  10. Mammoth ecosystem: Climatic areal, animal's density and cause of extinctions

    Science.gov (United States)

    Zimov, S.; Zimov, N.; Zimova, G.; Chapin, S. F.

    2008-12-01

    During the last glaciations Mammoth Ecosystem (ME) occupied territory from present-day France to Canada and from the Arctic islands to China. This ecosystem played major role in global carbon cycle and human settling around the planet. Causes of extinction of this ecosystem are debatable. Analyses of hundreds of radiocarbon dates of ME animal fossil remains showed that warming and moistening of climate wasn't accompanied by animal extinction. On the opposite, on the north right after the warming rise of herbivore population was observed. Reconstruction of ME climatic areal showed that its climatic optimum lies within range of annual precipitation of 200-350 mm and average summer temperatures of +8-+12oC which corresponds with modern climate of Northern Siberia. Analyses of bones and skeletons concentrations in permafrost of Northern Siberia showed that animal density in ME was similar to African savannah. That was a high productive ecosystem that could sustain in wide variety of climates because numerous herbivores maintained there pastures themselves.

  11. The impact of possible climate catastrophes on global warming policy

    International Nuclear Information System (INIS)

    Recent studies on global warming have introduced the inherent uncertainties associated with the costs and benefits of climate policies and have often shown that abatement policies are likely to be less aggressive or postponed in comparison to those resulting from traditional cost-benefit analyses (CBA). Yet, those studies have failed to include the possibility of sudden climate catastrophes. The aim of this paper is to account simultaneously for possible continuous and discrete damages resulting from global warming, and to analyse their implications on the optimal path of abatement policies. Our approach is related to the new literature on investment under uncertainty, and relies on some recent developments of the real option in which we incorporated negative jumps (climate catastrophes) in the stochastic process corresponding to the net benefits associated with the abatement policies. The impacts of continuous and discrete climatic risks can therefore be considered separately. Our numerical applications lead to two main conclusions: (i) gradual, continuous uncertainty in the global warming process is likely to delay the adoption of abatement policies as found in previous studies, with respect to the standard CBA; however (ii) the possibility of climate catastrophes accelerates the implementation of these policies as their net discounted benefits increase significantly

  12. Forest associations and global climate change - current climatic conditions; Forest associations and global climate change - CCCM climatic scenario; Forest associations and global climate change - GISS climatic scenario; Forest associations and global climate change - dT1 climatic scenario; 1 : 1 000 000

    International Nuclear Information System (INIS)

    Bioclimatic areas of wood species represent the areas of natural spreading of wood species as determined by the threshold values of air temperature by climatic amplitudes established for the individual wood species. Establishment of climatic amplitudes of the individual wood species in Slovakia was based on the existing studies, which analysed the results of natural spreading of wood species in Slovakia in relation to the vertical climatic changes. The presented bioclimatic areas are assessed for the following conditions (table): · Tn contemporary climate; · CCCM (Canadian Climate Center Model) climatic scenario; · GISS (Goddard Institute for Space Studies) climatic scenario; · dT1 (National Climatic Programme) climatic scenario. (authors)

  13. Numerical models

    Digital Repository Service at National Institute of Oceanography (India)

    Unnikrishnan, A.S.; Manoj, N.T.

    the wetted perimeter and A the area of cross section (excluding mud flats); C = (1.49/n)R1/6, where n is the Manning coefficient. The numerical scheme used by Harleman and Lee (1969) was used to solve the above equations. In this scheme, the continuity... equation is solved at odd grid points to compute eta at the next time step and the momentum equation is solved at even grid points to compute U . The original scheme of Harleman & Lee (1969) was developed for a single channel. For developing a model...

  14. Climate Change

    Science.gov (United States)

    ... in a place over a period of time. Climate change is major change in temperature, rainfall, snow, or ... by natural factors or by human activities. Today climate changes are occurring at an increasingly rapid rate. Climate ...

  15. NASA and the National Climate Assessment: Promoting awareness of NASA Earth science

    Science.gov (United States)

    Leidner, A. K.

    2014-12-01

    NASA Earth science observations, models, analyses, and applications made significant contributions to numerous aspects of the Third National Climate Assessment (NCA) report and are contributing to sustained climate assessment activities. The agency's goal in participating in the NCA was to ensure that NASA scientific resources were made available to understand the current state of climate change science and climate change impacts. By working with federal agency partners and stakeholder communities to develop and write the report, the agency was able to raise awareness of NASA climate science with audiences beyond the traditional NASA community. To support assessment activities within the NASA community, the agency sponsored two competitive programs that not only funded research and tools for current and future assessments, but also increased capacity within our community to conduct assessment-relevant science and to participate in writing assessments. Such activities fostered the ability of graduate students, post-docs, and senior researchers to learn about the science needs of climate assessors and end-users, which can guide future research activities. NASA also contributed to developing the Global Change Information System, which deploys information from the NCA to scientists, decision makers, and the public, and thus contributes to climate literacy. Finally, NASA satellite imagery and animations used in the Third NCA helped the pubic and decision makers visualize climate changes and were frequently used in social media to communicate report key findings. These resources are also key for developing educational materials that help teachers and students explore regional climate change impacts and opportunities for responses.

  16. Effects of climate variability and climate change on crop production in southern Mali

    NARCIS (Netherlands)

    Traore, B.; Corbeels, M.; Wijk, van M.T.; Rufino, M.C.; Giller, K.E.

    2013-01-01

    In West Africa predictions of future changes in climate and especially rainfall are highly uncertain, and up to now no long-term analyses are available of the effects of climate on crop production. This study analyses long-term trends in climate variability at N'Tarla and Sikasso in southern Mali us

  17. Economic analysis of climate change

    OpenAIRE

    Vojtíšek, Petr

    2012-01-01

    The bachelor thesis themed “Economic Analysis of Climate Change” focuses on the climate change from an economical point of view. The theoretical part sums up the basic facts about climate change, go through the most important social, environmental and economic impacts, main opinions about the climate change and also the main ideas of the mitigation and adaptation processes. The analyses tries to give the climate a monetary value with a use of non-market method to find out how much would be st...

  18. Numerical analysis

    CERN Document Server

    Jacques, Ian

    1987-01-01

    This book is primarily intended for undergraduates in mathematics, the physical sciences and engineering. It introduces students to most of the techniques forming the core component of courses in numerical analysis. The text is divided into eight chapters which are largely self-contained. However, with a subject as intricately woven as mathematics, there is inevitably some interdependence between them. The level of difficulty varies and, although emphasis is firmly placed on the methods themselves rather than their analysis, we have not hesitated to include theoretical material when we consider it to be sufficiently interesting. However, it should be possible to omit those parts that do seem daunting while still being able to follow the worked examples and to tackle the exercises accompanying each section. Familiarity with the basic results of analysis and linear algebra is assumed since these are normally taught in first courses on mathematical methods. For reference purposes a list of theorems used in the t...

  19. Numerical Analysis of Multiscale Computations

    CERN Document Server

    Engquist, Björn; Tsai, Yen-Hsi R

    2012-01-01

    This book is a snapshot of current research in multiscale modeling, computations and applications. It covers fundamental mathematical theory, numerical algorithms as well as practical computational advice for analysing single and multiphysics models containing a variety of scales in time and space. Complex fluids, porous media flow and oscillatory dynamical systems are treated in some extra depth, as well as tools like analytical and numerical homogenization, and fast multipole method.

  20. NUMERICAL ANALYSES OF THE UNDERGROUND EXPLOITATION OF DIMENSION STONE

    OpenAIRE

    1996-01-01

    Underground exploitation of dimension stone is spreading lately for three main reasons; economy, organisation and environment. Moreover, underground openings can be used for many purposes. Underground exploitation is different from surface quarrying only in the first stage, the removal of top slice, descending slices are worked as in conventional quarries. In underground stone quarries, stability problems require adequate studies in order to avoid expensive artificial support measures, ...

  1. Numerical tables. Physical and chemical analyses of Rhine water 1984

    International Nuclear Information System (INIS)

    Tables present the methods of analysis and the data obtained on inorganic, organic, and radioactive impurities in Rhine water. The measuring stations were located in Switzerland, France, West Germany, and the Netherlands. (HP)

  2. Future Climate Analysis

    International Nuclear Information System (INIS)

    This report documents an analysis that was performed to estimate climatic variables for the next 10,000 years by forecasting the timing and nature of climate change at Yucca Mountain, Nevada, the site of a repository for spent nuclear fuel and high-level radioactive waste. The future-climate estimates are based on an analysis of past-climate data from analog meteorological stations, and this report provides the rationale for the selection of these analog stations. The stations selected provide an upper and a lower climate bound for each future climate, and the data from those sites will provide input to the following reports: ''Simulation of Net Infiltration for Present-Day and Potential Future Climates'' (BSC 2004 [DIRS 170007]), ''Total System Performance Assessment (TSPA) Model/Analysis for the License Application'' (BSC 2004 [DIRS 168504]), ''Features, Events, and Processes in UZ Flow and Transport'' (BSC 2004 [DIRS 170012]), and ''Features, Events, and Processes in SZ Flow and Transport'' (BSC 2004 [DIRS 170013]). Forecasting long-term future climates, especially for the next 10,000 years, is highly speculative and rarely attempted. A very limited literature exists concerning the subject, largely from the British radioactive waste disposal effort. The discussion presented here is one available forecasting method for establishing upper and lower bounds for future climate estimates. The selection of different methods is directly dependent on the available evidence used to build a forecasting argument. The method used here involves selecting a particular past climate from many past climates, as an analog for future climate. While alternative analyses are possible for the case presented for Yucca Mountain, the evidence (data) used would be the same and the conclusions would not be expected to drastically change. Other studies might develop a different rationale or select other past climates resulting in a different future climate analog. Other alternative

  3. Future Climate Analysis

    Energy Technology Data Exchange (ETDEWEB)

    C. G. Cambell

    2004-09-03

    This report documents an analysis that was performed to estimate climatic variables for the next 10,000 years by forecasting the timing and nature of climate change at Yucca Mountain, Nevada, the site of a repository for spent nuclear fuel and high-level radioactive waste. The future-climate estimates are based on an analysis of past-climate data from analog meteorological stations, and this report provides the rationale for the selection of these analog stations. The stations selected provide an upper and a lower climate bound for each future climate, and the data from those sites will provide input to the following reports: ''Simulation of Net Infiltration for Present-Day and Potential Future Climates'' (BSC 2004 [DIRS 170007]), ''Total System Performance Assessment (TSPA) Model/Analysis for the License Application'' (BSC 2004 [DIRS 168504]), ''Features, Events, and Processes in UZ Flow and Transport'' (BSC 2004 [DIRS 170012]), and ''Features, Events, and Processes in SZ Flow and Transport'' (BSC 2004 [DIRS 170013]). Forecasting long-term future climates, especially for the next 10,000 years, is highly speculative and rarely attempted. A very limited literature exists concerning the subject, largely from the British radioactive waste disposal effort. The discussion presented here is one available forecasting method for establishing upper and lower bounds for future climate estimates. The selection of different methods is directly dependent on the available evidence used to build a forecasting argument. The method used here involves selecting a particular past climate from many past climates, as an analog for future climate. While alternative analyses are possible for the case presented for Yucca Mountain, the evidence (data) used would be the same and the conclusions would not be expected to drastically change. Other studies might develop a different rationale or select other past

  4. Temperate climate - Innovative outputs nexus

    OpenAIRE

    Coccia, M.

    2014-01-01

    Technological change is a vital human activity that interacts with geographic factors and environment. The purpose of the study here is to analyse the relationship between geo-climate zones of the globe and technological outputs in order to detect favourable areas that spur higher technological change and, as a consequence, human development. The main finding is that innovative outputs are higher in geographical areas with a temperate climate (latitudes). In fact, warm temperate climates are ...

  5. The volcanic contribution to climate change of the past 100 years

    International Nuclear Information System (INIS)

    Volcanic eruptions which inject large amounts of sulfur-rich gas into the stratosphere produce dust veils which last several years and cool the earth's surface. At the same time these dust veils absorb enough solar radiation to warm the stratosphere. Since these temperature changes at the earth's surface and in the stratosphere are both in the opposite direction to the hypothesized effects from greenhouse gases, they act to delay and mask the detection of greenhouse effects on the climate system. A large portion of the global climate change of the past 100 years may be due to the effects of volcanoes, but a definitive answer is not yet clear. While effects over several years have been demonstrated with both data studies and numerical models, long-term effects, while found in climate model calculations, await confirmation with more realistic models. In this paper chronologies of past volcanic eruptions and the evidence from data analyses and climate model calculations are reviewed

  6. Climate Projections and Uncertainty Communication.

    Science.gov (United States)

    Joslyn, Susan L; LeClerc, Jared E

    2016-01-01

    Lingering skepticism about climate change might be due in part to the way climate projections are perceived by members of the public. Variability between scientists' estimates might give the impression that scientists disagree about the fact of climate change rather than about details concerning the extent or timing. Providing uncertainty estimates might clarify that the variability is due in part to quantifiable uncertainty inherent in the prediction process, thereby increasing people's trust in climate projections. This hypothesis was tested in two experiments. Results suggest that including uncertainty estimates along with climate projections leads to an increase in participants' trust in the information. Analyses explored the roles of time, place, demographic differences (e.g., age, gender, education level, political party affiliation), and initial belief in climate change. Implications are discussed in terms of the potential benefit of adding uncertainty estimates to public climate projections. PMID:26695995

  7. The climate file

    International Nuclear Information System (INIS)

    A series of interviews of a member of the IPCC (Intergovernmental Panel on Climate Change) and of researchers gives an overview of scientific knowledge on climate, discusses what could be a good agreement at the Copenhagen conference, outlines what is at stake in these negotiations, and proposes an overview of the French policy for the struggle against climate change. An article comments the content of a report published by the CAS (Centre d'Analyse Strategique), and more particularly the position of Russia and of the OPEC before the Copenhagen negotiations. A last article comments the results of three opinion surveys made in France about climate change, its origins and solutions, and about the representation French people have of greenhouse effect

  8. Apports de l’analyse de la conformité réglementaire, de l’analyse des risques professionnels et de l'évaluation du climat de sécurité à la construction de la culture de sécurité

    OpenAIRE

    Lefranc, Guénolé

    2012-01-01

    Safety culture is increasingly important to the corporate agenda. The SafetyCulture concept is not new, but gained popularity in the late 80s following the Chernobyl accident. The main cause of the disaster was said to be a deficient Safety culture.The term is now used widely and definitions are numerous. The Safety culture literature contains three major explanatory factors shaping the formation of a safety culture: "organizational", "behavioural" and "psychological".The objective of this th...

  9. Climate and happiness

    Energy Technology Data Exchange (ETDEWEB)

    Rehdanz, Katrin [Centre for Marine and Climate Research, Hamburg University, Hamburg (Germany); Maddison, David [Department of Economics, University of Southern Denmark, Odense (Denmark)

    2005-01-05

    Climate is an important input to many human activities. Climate affects heating and cooling requirements, health, clothing and nutritional needs as well as recreational activities. As such, it is to be expected that individuals will have a preference for particular types of climate. This paper analyses a panel of 67 countries attempting to explain differences in self-reported levels of happiness by reference to, amongst other things, temperature and precipitation. Various indices are used for each of these variables, including means, extremes and the number of hot, cold, wet and dry months. Using a panel-corrected least squares approach, the paper demonstrates that, even when controlling for a range of other factors, climate variables have a highly significant effect on country-wide self-reported levels of happiness. On the basis of these results, it is determined that differential patterns of anthropogenically induced climate change might alter dramatically the distribution of happiness between nations, with some countries moving towards a preferred climate and others moving further away. We find that high-latitude countries included in our dataset might benefit from temperature changes. Countries already characterized by very high summer temperatures would most likely suffer losses from climate change.

  10. Climate and happiness

    International Nuclear Information System (INIS)

    Climate is an important input to many human activities. Climate affects heating and cooling requirements, health, clothing and nutritional needs as well as recreational activities. As such, it is to be expected that individuals will have a preference for particular types of climate. This paper analyses a panel of 67 countries attempting to explain differences in self-reported levels of happiness by reference to, amongst other things, temperature and precipitation. Various indices are used for each of these variables, including means, extremes and the number of hot, cold, wet and dry months. Using a panel-corrected least squares approach, the paper demonstrates that, even when controlling for a range of other factors, climate variables have a highly significant effect on country-wide self-reported levels of happiness. On the basis of these results, it is determined that differential patterns of anthropogenically induced climate change might alter dramatically the distribution of happiness between nations, with some countries moving towards a preferred climate and others moving further away. We find that high-latitude countries included in our dataset might benefit from temperature changes. Countries already characterized by very high summer temperatures would most likely suffer losses from climate change

  11. Developing the architecture for the Climate Information Portal for Copernicus

    Science.gov (United States)

    Som de Cerff, Wim; Thijsse, Peter; Plieger, Maarten; Pascoe, Stephen; Jukes, Martin; Leadbetter, Adam; Goosen, Hasse; de Vreede, Ernst

    2015-04-01

    Climate change is impacting the environment, society and policy decisions. Information about climate change is available from many sources, but not all of them are reliable. The CLIPC project is developing a portal to provide a single point of access for authoritative scientific information on climate change. This ambitious objective is made possible through the Copernicus Earth Observation Programme for Europe, which will deliver a new generation of environmental measurements of climate quality. The data about the physical environment which is used to inform climate change policy and adaptation measures comes from several categories: satellite measurements, terrestrial observing systems, model projections and simulations and from re-analyses (syntheses of all available observations constrained with numerical weather prediction systems). These data categories are managed by different communities: CLIPC will provide a single point of access for the whole range of data. Information on data value and limitations will be provided as part of a knowledge base of authoritative climate information. The impacts of climate change on society will generally reflect a range of different environmental and climate system changes, and different sectors and actors within society will react differently to these changes. The CLIPC portal will provide some a number of indicators showing impacts on specific sectors which have been generated using a range of factors selected through structured expert consultation. It will also, as part of the transformation services, allow users to explore the consequences of using different combinations of driving factors which they consider to be of particular relevance to their work or life. The portal will provide information on the scientific quality and pitfalls of such transformations to prevent misleading usage of the results. The CLIPC project will not be able to process a comprehensive range of climate change impacts on the physical

  12. Coping with Climatic Variability by Rain-fed Farmers in Dry Zone, Sri Lanka: Towards Understanding Adaptation to Climate Change

    OpenAIRE

    Senaratne, Athula; Scarborough, Helen

    2011-01-01

    Climate change introduces numerous uncertainties over the livelihoods of farming communities that depend heavily on weather and climate. Rain-fed farmers in developing countries are among the most vulnerable communities. However, climate risks are not new to farmers. Coping with ‘natural variability’ of climate has been a constant challenge faced by farmers even though broad sweeping change in climate due to anthropogenic causes is a relatively new prospect. Some argue ‘climate change’ could ...

  13. Climate Informatics

    Science.gov (United States)

    Monteleoni, Claire; Schmidt, Gavin A.; Alexander, Francis J.; Niculescu-Mizil, Alexandru; Steinhaeuser, Karsten; Tippett, Michael; Banerjee, Arindam; Blumenthal, M. Benno; Ganguly, Auroop R.; Smerdon, Jason E.; Tedesco, Marco

    2013-01-01

    The impacts of present and potential future climate change will be one of the most important scientific and societal challenges in the 21st century. Given observed changes in temperature, sea ice, and sea level, improving our understanding of the climate system is an international priority. This system is characterized by complex phenomena that are imperfectly observed and even more imperfectly simulated. But with an ever-growing supply of climate data from satellites and environmental sensors, the magnitude of data and climate model output is beginning to overwhelm the relatively simple tools currently used to analyze them. A computational approach will therefore be indispensable for these analysis challenges. This chapter introduces the fledgling research discipline climate informatics: collaborations between climate scientists and machine learning researchers in order to bridge this gap between data and understanding. We hope that the study of climate informatics will accelerate discovery in answering pressing questions in climate science.

  14. Climate Change

    Science.gov (United States)

    ... can be caused by natural factors or by human activities. Today climate changes are occurring at an increasingly rapid rate. Climate change can affect our health. It can lead to More heat-related illness ...

  15. Triple oxygen and sulfur isotope analyses of sulfate extracted from voluminous volcanic ashes in the Oligocene John Day Formation: insight into dry climate conditions and ozone contribution to supereruptions

    Science.gov (United States)

    Workman, J.; Bindeman, I. N.; Martin, E.; Retallack, G.; Palandri, J. L.; Weldon, N.

    2014-12-01

    Large volume pyroclastic silicic eruptions emit hundreds of megatons of SO2 into the troposphere and stratosphere that is oxidized into sulfuric acid (H2SO4) by a variety of reactions with mass independent oxygen signatures (MIF), Δ17O>0. Sulfuric acid is then preserved as gypsum in parental volcanic deposits. Diagenic effects are mass dependent and can dilute, but otherwise do not affect MIF ratios. Pleistocene Yellowstone and Bishop tuffs and modern volcanic eruptions preserved under arid climate conditions in North American playa lakes, preserve small amounts of volcanic sulfate as gypsum. This gypsum's Δ17O>0, in combination with isotopic variations of δ18O, δ33S and δ34S is distinct from sedimentary sulfate and reveals its original MIF sulfate isotopic signal and the effect of super eruptions on the atmosphere, and ozone consumption in particular. We use linear algebraic equations to resolve volcanic versus sedimentary (MIF=0) sources. We have found that many large volume ignimbrites have very high initial Δ17O in volcanic sulfate that can only be acquired from reaction with stratospheric ozone. We here investigate nine thick (>2 m) ash beds ranging in age from ~33-23 Ma in the John Day Formation of central Oregon, including massive 28.6 Ma Picture Gorge tuff of newly identified Crooked River supercaldera. The 28.6 Ma Picture Gorge tuff (PGT) has the highest measured Δ17O of 3.5‰, and other tuffs (Tin Roof, Biotite, Deep Creek) have +1.3 to 3.4‰ Δ17O excesses. Sulfate from modern smaller tropospheric eruptions studied for comparison have a resolvable 0.4‰ range consistent with liquid-phase based H2O2 oxidation. The PGT is coeval with the ignimbrite flare-up in western N. America, the 28-29 Ma eruption of the 5000 km3 Fish Canyon tuff and the 28 Ma Never Summer Field eruption in Nebraska-Colorado that have the highest measured Δ17O of 6‰ (Bao et al. 2003). We speculate on the climatic/atmospheric effects of these multiple ~28 Ma supereruptions

  16. Stable isotopic analyses in paleoclimatic reconstruction

    Energy Technology Data Exchange (ETDEWEB)

    Wigand, P.E. [Univ. and Community College System of Nevada, Reno, NV (United States)

    1995-09-01

    Most traditional paleoclimatic proxy data have inherent time lags between climatic input and system response that constrain their use in accurate reconstruction of paleoclimate chronology, scaling of its variability, and the elucidation of the processes that determine its impact on the biotic and abiotic environment. With the exception of dendroclimatology, and studies of short-lived organisms and pollen recovered from annually varved lacustrine sediments, significant periods of time ranging from years, to centuries, to millennia may intervene between climate change and its first manifestation in paleoclimatic proxy data records. Reconstruction of past climate through changes in plant community composition derived from pollen sequences and plant remains from ancient woodrat middens, wet environments and dry caves all suffer from these lags. However, stable isotopic analyses can provide more immediate indication of biotic response to climate change. Evidence of past physiological response of organisms to changes in effective precipitation as climate varies can be provided by analyses of the stable isotopic content of plant macrofossils from various contexts. These analyses consider variation in the stable isotopic (hydrogen, oxygen and carbon) content of plant tissues as it reflects (1) past global or local temperature through changes in meteoric (rainfall) water chemistry in the case of the first two isotopes, and (2) plant stress through changes in plant respiration/transpiration processes under differing water availability, and varying atmospheric CO, composition (which itself may actually be a net result of biotic response to climate change). Studies currently being conducted in the Intermountain West indicate both long- and short-term responses that when calibrated with modem analogue studies have the potential of revealing not only the timing of climate events, but their direction, magnitude and rapidity.

  17. Analysis of climatically relevant processes in the troposphere using ground-based remote measuring methods (windprofiler/RASS). Final report; Analyse klimatisch relevanter Prozesse in der Troposphaere mit Hilfe bodengebundener Fernerkundungsmethoden (Windprofiler/RASS). Abschlussbericht

    Energy Technology Data Exchange (ETDEWEB)

    Steinhagen, H.; Christoph, A.; Engelbart, D.; Goersdorf, U.; Hirsch, L.; Lippmann, J.; Neisser, J.; Wergen, W.

    1995-09-01

    In the framework of the present research project the Meterological Observatory of Lindenberg (MOL) was equipped with the scientific and technical means necessary for the future operational application at the German weather service of ground-based remote sounding technologies such as `windprofiler radar`, radio-acoustic sounding system (RASS). Several case studies were used to demonstrate the multifarious possibilities of analysing mesoscale tropospheric structures by means of windprofiler radar and RASS. Besides this, further information such as mixing layer thickness and heat flux were derived from windprofiler and RASS measurements and the applied algorithms were tried on case examples. (orig./AKF) [Deutsch] Im Rahmen dieses Forschungsvorhabens sind am Meteorologischen Observatorium Lindenberg (MOL) wissenschaftliche und technische Voraussetzungen fuer eine zukuenftige operationelle Anwendung aktiver bodengebundener Fernsondierungstechnologien, wie `Windprofiler-Radar` und `Radio-Akustisches-Sondierungs-System (RASS)` im Deutschen Wetterdienst geschaffen worden. An Hand mehrerer Fallstudien wurden die vielfaeltigen Moeglichkeiten zur Analyse mesoskaliger troposphaerischer Strukturen mit Windprofiler-Radar und RASS demonstriert. Darueber hinaus wurden aus Windprofiler-/RASS-Messungen weiterfuehrende Informationen, wie Mischungsschichthoehe und Waermefluss abgeleitet und die entsprechenden Algorithmen am Fallbeispielen erprobt. (orig./AKF)

  18. Nonlinearly combined impacts of initial perturbation from human activities and parameter perturbation from climate change on the grassland ecosystem

    Directory of Open Access Journals (Sweden)

    G. Sun

    2011-11-01

    Full Text Available Human activities and climate change are important factors that affect grassland ecosystems. A new optimization approach, the approach of conditional nonlinear optimal perturbation (CNOP related to initial and parameter perturbations, is employed to explore the nonlinearly combined impacts of human activities and climate change on a grassland ecosystem using a theoretical grassland model. In our study, it is assumed that the initial perturbations and parameter perturbations are regarded as human activities and climate change, respectively. Numerical results indicate that the climate changes causing the maximum effect in the grassland ecosystem are different under disparate intensities of human activities. This implies the pattern of climate change is very critical to the maintenance or degradation of grassland ecosystem in light of high intensity of human activities and that the grassland ecosystem should be rationally managed when the moisture index decreases. The grassland ecosystem influenced by the nonlinear combination of human activities and climate change undergoes abrupt change, while the grassland ecosystem affected by other types of human activities and climate change fails to show the abrupt change under a certain range of perturbations with the theoretical model. The further numerical analyses also indicate that the growth of living biomass and the evaporation from soil surface shaded by the wilted biomass may be crucial factors contributing to the abrupt change of the grassland equilibrium state within the theoretical model.

  19. Celebrity Climate Contrarians: Understanding a keystone species in contemporary climate science-policy-public interactions

    Science.gov (United States)

    Boykoff, M. T.

    2012-12-01

    Since the 1980s, a keystone species called 'climate contrarians' has emerged and thrived. Through resistance to dominant interpretations of scientific evidence, and often outlier views on optimal responses to climate threats, contrarians have raised many meta-level questions: for instance, questions involve to what extent have their varied interventions been effective in terms of sparking a new and wise Copernican revolution; or do their amplified voices instead service entrenched carbon-based industry interests while they blend debates over 'climate change' with other culture wars? While the value of their influence has generated numerous debates, there is no doubt that climate contrarians have had significant influence on climate science, policy and public communities in ways that are larger than would be expected from their relative abundance in society. As such, a number of these actors have achieved 'celebrity status' in science-policy circles, and, at times, larger public spaces. This presentation focuses on how - particularly through amplified mass media attention to their movements - various outlier interventions have demonstrated themselves to be (often deliberately) detrimental to efforts that seek to enlarge rather than constrict the spectrum of possibility for mobilizing appropriate responses to ongoing climate challenges. Also, this work analyses the growth pathways of these charismatic megafauna through interview data and participant observations completed by the author at the 2011 Heartland Institute's Sixth International Conference on Climate Change. This provides detail on how outlier perspectives characterized as climate contrarians do work in these spaces under the guise of public intellectualism to achieve intended goals and objectives. The research undertaken and related in the presentation here seeks to better understand motivations that prop up these contrarian stances, such as possible ideological or evidentiary disagreement to the orthodox

  20. Climatologie des états de mer en Atlantique nord-est : analyse du climat actuelet des évolutions futures sous scénarios de changement climatique par descente d'échelle dynamique et statistique

    OpenAIRE

    Laugel, Amélie

    2013-01-01

    L'analyse de la climatologie des aléas océano-météorologiques tels que les états de mer est fondamentale pour comprendre l'évolution et la dynamique des zones côtières, estimer les risques naturels survenant lors d'événements de tempête majeurs, définir les moyens optimaux de protection des ports et infrastructures onshore et offshore, caractériser la ressource houlomotrice pour des projets de récupération d'énergie des vagues, comprendre les processus d'érosion et accrétion des plages, etc. ...

  1. "Climate change" and vulnerability analysis: poor will become poorer

    OpenAIRE

    Ozer, Pierre

    2013-01-01

    The recent Intergovernmental Panel on Climate Change’s Fifth Assessment Report (IPCC-AR5) considers new evidence of climate change based on many independent scientific analyses from observations of the climate system, paleoclimate archives, theoretical studies of climate processes and simulations using climate models. “Warming of the climate system is unequivocal, and since the 1950s, many of the observed changes are unprecedented over decades to millennia. The atmosphere and ocean have warme...

  2. Climate change and skin.

    Science.gov (United States)

    Balato, N; Ayala, F; Megna, M; Balato, A; Patruno, C

    2013-02-01

    Global climate appears to be changing at an unprecedented rate. Climate change can be caused by several factors that include variations in solar radiation received by earth, oceanic processes (such as oceanic circulation), plate tectonics, and volcanic eruptions, as well as human-induced alterations of the natural world. Many human activities, such as the use of fossil fuel and the consequent accumulation of greenhouse gases in the atmosphere, land consumption, deforestation, industrial processes, as well as some agriculture practices are contributing to global climate change. Indeed, many authors have reported on the current trend towards global warming (average surface temperature has augmented by 0.6 °C over the past 100 years), decreased precipitation, atmospheric humidity changes, and global rise in extreme climatic events. The magnitude and cause of these changes and their impact on human activity have become important matters of debate worldwide, representing climate change as one of the greatest challenges of the modern age. Although many articles have been written based on observations and various predictive models of how climate change could affect social, economic and health systems, only few studies exist about the effects of this change on skin physiology and diseases. However, the skin is the most exposed organ to environment; therefore, cutaneous diseases are inclined to have a high sensitivity to climate. For example, global warming, deforestation and changes in precipitation have been linked to variations in the geographical distribution of vectors of some infectious diseases (leishmaniasis, lyme disease, etc) by changing their spread, whereas warm and humid environment can also encourage the colonization of the skin by bacteria and fungi. The present review focuses on the wide and complex relationship between climate change and dermatology, showing the numerous factors that are contributing to modify the incidence and the clinical pattern of many

  3. Effect of Climate Change on Air Quality

    OpenAIRE

    Jacob, Daniel J.; Winner, Darrel A.

    2009-01-01

    Air quality is strongly dependent on weather and is therefore sensitive to climate change. Recent studies have provided estimates of this climate effect through correlations of air quality with meteorological variables, perturbation analyses in chemical transport models (CTMs), and CTM simulations driven by general circulation model (GCM) simulations of 21st-century climate change. We review these different approaches and their results. The future climate is expected to be more stagnant, due ...

  4. Seasonal Variability of Wind Climate in Hungary

    OpenAIRE

    PÉLINÉ NÉMETH, Csilla; RADICS, Kornélia; Bartholy, Judit

    2011-01-01

    One of the most important effects of climate variability and climate change may comefrom changes in the intensity and frequency of climatic extremes. Responding to the need of newclimatologic analyses, complex wind field research was carried out to study and provide reliableinformation about the state and variability of wind climate in Hungary. First of all, special attentionwas paid on creation of a high quality, homogeneous data series. The research is based on 36-yearlong(1975–2010) wind d...

  5. Operational Numerical Weather Prediction systems based on Linux cluster architectures

    International Nuclear Information System (INIS)

    The progress in weather forecast and atmospheric science has been always closely linked to the improvement of computing technology. In order to have more accurate weather forecasts and climate predictions, more powerful computing resources are needed, in addition to more complex and better-performing numerical models. To overcome such a large computing request, powerful workstations or massive parallel systems have been used. In the last few years, parallel architectures, based on the Linux operating system, have been introduced and became popular, representing real high performance-low cost systems. In this work the Linux cluster experience achieved at the Laboratory far Meteorology and Environmental Analysis (LaMMA-CNR-IBIMET) is described and tips and performances analysed

  6. Evaluating Parameterizations in General Circulation Models: Climate Simulation Meets Weather Prediction

    Energy Technology Data Exchange (ETDEWEB)

    Phillips, T J; Potter, G L; Williamson, D L; Cederwall, R T; Boyle, J S; Fiorino, M; Hnilo, J J; Olson, J G; Xie, S; Yio, J J

    2004-05-06

    To significantly improve the simulation of climate by general circulation models (GCMs), systematic errors in representations of relevant processes must first be identified, and then reduced. This endeavor demands that the GCM parameterizations of unresolved processes, in particular, should be tested over a wide range of time scales, not just in climate simulations. Thus, a numerical weather prediction (NWP) methodology for evaluating model parameterizations and gaining insights into their behavior may prove useful, provided that suitable adaptations are made for implementation in climate GCMs. This method entails the generation of short-range weather forecasts by a realistically initialized climate GCM, and the application of six-hourly NWP analyses and observations of parameterized variables to evaluate these forecasts. The behavior of the parameterizations in such a weather-forecasting framework can provide insights on how these schemes might be improved, and modified parameterizations then can be tested in the same framework. In order to further this method for evaluating and analyzing parameterizations in climate GCMs, the U.S. Department of Energy is funding a joint venture of its Climate Change Prediction Program (CCPP) and Atmospheric Radiation Measurement (ARM) Program: the CCPP-ARM Parameterization Testbed (CAPT). This article elaborates the scientific rationale for CAPT, discusses technical aspects of its methodology, and presents examples of its implementation in a representative climate GCM.

  7. [Research on greenhouse-gas-induced climate change

    Energy Technology Data Exchange (ETDEWEB)

    Schlesinger, M.

    1995-12-31

    This climate research focuses on the following topics: model development and testing; climate simulations and analyses; analyses of observed climate; development of analysis methods; global warming: physics, economics and policy; and participation in international research efforts. Also summarized are six projects that are proposed for the next five years.

  8. The application analyses for primary spectrum pyrometer

    Institute of Scientific and Technical Information of China (English)

    FU; TaiRan

    2007-01-01

    In the applications of primary spectrum pyrometry, based on the dynamic range and the minimum sensibility of the sensor, the application issues, such as the measurement range and the measurement partition, were investigated through theoretical analyses. For a developed primary spectrum pyrometer, the theoretical predictions of measurement range and the distributions of measurement partition were presented through numerical simulations. And the measurement experiments of high-temperature blackbody and standard temperature lamp were processed to further verify the above theoretical analyses and numerical results. Therefore the research in the paper provides the helpful supports for the applications of primary spectrum pyrometer and other radiation pyrometers.……

  9. Climate Change

    DEFF Research Database (Denmark)

    Rasmussen, Torben Valdbjørn; Hansen, Ernst Jan de Place

    2011-01-01

    This paper presents the effects of climate change relevant for Denmark, including the change in mean year values as well as the extent of maximum and minimum extremes. Described by the Intergovernmental Panel on Climate Change, the assumptions that the scenarios are based on were outlined and...... evaluated in a Danish context. The uncertainty of the scenarios leaves major challenges that, if not addressed and taken into account in building design, will grow far more serious as climate change progresses. Cases implemented in the Danish building stock illustrate adaptation to climate change and...... illustrate how building design can include mitigating measures to counteract climate change. Cases studied were individual buildings as well as the urban environment. Furthermore the paper describes some of the issues that must be addressed, as the building sector is investing in measures to adapt to climate...

  10. Climate change

    International Nuclear Information System (INIS)

    Based on contributions on 120 French and foreign scientists representing different disciplines (mathematics, physics, mechanics, chemistry, biology, medicine, and so on), this report proposes an overview of the scientific knowledge and debate about climate change. It discusses the various indicators of climate evolution (temperatures, ice surfaces, sea level, biological indicators) and the various factors which may contribute to climate evolution (greenhouse gases, solar radiation). It also comments climate evolutions in the past as they can be investigated through some geological, thermal or geochemical indicators. Then, the authors describe and discuss the various climate mechanisms: solar activity, oceans, ice caps, greenhouse gases. In a third part, the authors discuss the different types of climate models which differ by the way they describe processes, and the current validation process for these models

  11. Climate Change

    DEFF Research Database (Denmark)

    Rasmussen, Torben Valdbjørn; Hansen, Ernst Jan de Place

    2011-01-01

    This paper presents the effects of climate change relevant for Denmark, including the change in mean year values as well as the extent of maximum and minimum extremes. Described by the Intergovernmental Panel on Climate Change, the assumptions that the scenarios are based on were outlined...... and evaluated in a Danish context. The uncertainty of the scenarios leaves major challenges that, if not addressed and taken into account in building design, will grow far more serious as climate change progresses. Cases implemented in the Danish building stock illustrate adaptation to climate change...... and illustrate how building design can include mitigating measures to counteract climate change. Cases studied were individual buildings as well as the urban environment. Furthermore the paper describes some of the issues that must be addressed, as the building sector is investing in measures to adapt to climate...

  12. The importance of buisiness climate and people climate on regional rerformance

    DEFF Research Database (Denmark)

    Eriksson, Rikard; Hansen, Høgni Kalsø; Lindgren, Urban

    2014-01-01

    capita (GRP) at the regional level, this paper analyses the influence of business climate (business-friendly assets) and people climate (amenities). Based on panel-data regressions, it is shown that both business and people climate are related to regional performance. The exact nature of these...

  13. Ultrascale Visualization of Climate Data

    Science.gov (United States)

    Williams, Dean N.; Bremer, Timo; Doutriaux, Charles; Patchett, John; Williams, Sean; Shipman, Galen; Miller, Ross; Pugmire, David R.; Smith, Brian; Steed, Chad; Bethel, E. Wes; Childs, Hank; Krishnan, Harinarayan; Prabhat; Wehner, Michael; Silva, Claudio T.; Santos, Emanuele; Koop, David; Ellqvist, Tommy; Poco, Jorge; Gevecki, Berk; Chaudhary, Aashish; Bauer, Andy; Potter, Gerald L.; Maxwell, Thomas P.

    2013-01-01

    Fueled by exponential increases in the computational and storage capabilities of high-performance computing platforms, climate simulations are evolving toward higher numerical fidelity, complexity, volume, and dimensionality. These technological breakthroughs are coming at a time of exponential growth in climate data, with estimates of hundreds of exabytes by 2020. To meet the challenges and exploit the opportunities that such explosive growth affords, a consortium of four national laboratories, two universities, a government agency, and two private companies formed to explore the next wave in climate science. Working in close collaboration with domain experts, the Ultrascale Visualization Climate Data Analysis Tools (UV-CDAT) project aims to provide high-level solutions to a variety of climate data analysis and visualization problems.

  14. Stochastic Climate Theory and Modelling

    CERN Document Server

    Franzke, Christian L E; Berner, Judith; Williams, Paul D; Lucarini, Valerio

    2014-01-01

    Stochastic methods are a crucial area in contemporary climate research and are increasingly being used in comprehensive weather and climate prediction models as well as reduced order climate models. Stochastic methods are used as subgrid-scale parameterizations as well as for model error representation, uncertainty quantification, data assimilation and ensemble prediction. The need to use stochastic approaches in weather and climate models arises because we still cannot resolve all necessary processes and scales in comprehensive numerical weather and climate prediction models. In many practical applications one is mainly interested in the largest and potentially predictable scales and not necessarily in the small and fast scales. For instance, reduced order models can simulate and predict large scale modes. Statistical mechanics and dynamical systems theory suggest that in reduced order models the impact of unresolved degrees of freedom can be represented by suitable combinations of deterministic and stochast...

  15. Climate Certainties and Uncertainties

    International Nuclear Information System (INIS)

    In issue 380 of Futuribles in December 2011, Antonin Pottier analysed in detail the workings of what is today termed 'climate scepticism' - namely the propensity of certain individuals to contest the reality of climate change on the basis of pseudo-scientific arguments. He emphasized particularly that what fuels the debate on climate change is, largely, the degree of uncertainty inherent in the consequences to be anticipated from observation of the facts, not the description of the facts itself. In his view, the main aim of climate sceptics is to block the political measures for combating climate change. However, since they do not admit to this political posture, they choose instead to deny the scientific reality. This month, Futuribles complements this socio-psychological analysis of climate-sceptical discourse with an - in this case, wholly scientific - analysis of what we know (or do not know) about climate change on our planet. Pierre Morel gives a detailed account of the state of our knowledge in the climate field and what we are able to predict in the medium/long-term. After reminding us of the influence of atmospheric meteorological processes on the climate, he specifies the extent of global warming observed since 1850 and the main origin of that warming, as revealed by the current state of knowledge: the increase in the concentration of greenhouse gases. He then describes the changes in meteorological regimes (showing also the limits of climate simulation models), the modifications of hydrological regimes, and also the prospects for rises in sea levels. He also specifies the mechanisms that may potentially amplify all these phenomena and the climate disasters that might ensue. Lastly, he shows what are the scientific data that cannot be disregarded, the consequences of which are now inescapable (melting of the ice-caps, rises in sea level etc.), the only remaining uncertainty in this connection being the date at which these things will happen. 'In this

  16. Climate variability and climate change

    International Nuclear Information System (INIS)

    Changes of variability with climate change are likely to have a substantial impact on vegetation and society, rivaling the importance of changes in the mean values themselves. A variety of paleoclimate and future climate simulations performed with the GISS global climate model is used to assess how the variabilities of temperature and precipitation are altered as climate warms or cools. In general, as climate warms, temperature variability decreases due to reductions in the latitudinal temperature gradient and precipitation variability increases together with the intensity of the hydrologic cycle. If future climate projections are accurate, the reduction in temperature variability will be minimized by the rapid change in mean temperatures, but the hydrologic variability will be amplified by increased evapotranspiration. Greater hydrologic variability would appear to pose a potentially severe problem for the next century. 19 refs.; 3 figs.; 2 tabs

  17. Climate variability and climate change

    International Nuclear Information System (INIS)

    Changes of variability with climate change are likely to have a substantial impact on vegetation and society, rivaling the importance of changes in the mean values themselves. A variety of paleoclimate and future climate simulations performed with the GISS global climate model is used to assess how the variabilities of temperature and precipitation are altered as climate warms or cools. In general, as climate warms, temperature variability decreases due to reductions in the latitudinal temperature gradient and precipitation variability increases together with the intensity of the hydrologic cycle. If future climate projections are accurate, the reduction in temperature variability will be minimized by the rapid change in mean temperatures, but the hydrologic variability will be amplified by increased evapotranspiration. Greater hydrologic variability would appear to pose a potentially severe problem for the next century

  18. Etude Climat no. 37 '10 lessons from 10 years of the CDM'

    International Nuclear Information System (INIS)

    Among the publications of CDC Climat Research, 'Climate Reports' offer in-depth analyses on a given subject. This issue addresses the following points: The Clean Development Mechanism (CDM) is the first and by far the largest carbon offset instrument in the world. To date, it is the only market based on an environmental commodity which managed to attract several billions of euros of private capital on an annual basis. Being the first-of-a-kind climate change mitigation instrument, the CDM followed a 'learning by doing' pattern undergoing numerous reforms throughout its more than 10-year history. Although the post-2012 fate of the mechanism remains uncertain, one should not 'throw out the baby with the bath water' as the lessons from the CDM experience may be useful not only for the CDM reform but also for new market instruments

  19. Numerical algorithms in secondary creep

    International Nuclear Information System (INIS)

    The problem of stationary creep is presented as well as its variational formulation, when weak constraints are established, capable of assuring one single solution. A second, so-called elasto-creep problem, is further analysed, together with its variational formulation. It is shown that its stationary solution coincides with that of the stationary creep and the advantages of this formulation with respect to the former one is emphasized. Some numerical applications showing the efficiency of the method propesed are finally presented

  20. Numerical simulation of drifting sand

    OpenAIRE

    Alhajraf, Salem

    2000-01-01

    Two-phase flows are involved in many industrial and natural flow phenomena varying from as specific as the transport of crude oil in pipelines to as general as the dispersion of pollutants in the atmosphere. Numerical modelling based on Computational Fluid Dynamics (CFD), has attracted the attention of scientists and engineers from a wide range of backgrounds over recent decades during which these models have been extensively developed, analysed and applied to many practical...

  1. Climate impacts of Australian land cover change

    Science.gov (United States)

    Lawrence, P. J.

    2004-05-01

    Australian land cover has been dramatically altered since European settlement primarily for agricultural utilization, with native vegetation widely replaced or modified for cropping and intensive animal production. While there have been numerous investigations into the regional and near surface climate impacts of Australian land cover change, these investigation have not included the climate impacts of larger-scale changes in atmospheric circulation and their associated feedbacks, or the impacts of longer-term soil moisture feedbacks. In this research the CSIRO General Circulation Model (GCM) was used to investigate the climate impacts of Australian land cover change, with larger-scale and longer-term feedbacks. To avoid the common problem of overstating the magnitude and spatial extent of changes in land surface conditions prescribed in land cover change experiments, the current Australian land surface properties were described from finer-scale, satellite derived land cover datasets, with land surface conditions extrapolating from remnant native vegetation to pre-clearing extents to recreate the pre-clearing land surface properties. Aggregation rules were applied to the fine-scale data to generate the land surface parameters of the GCM, ensuring the equivalent sub-grid heterogeneity and land surface biogeophysics were captured in both the current and pre-clearing land surface parameters. The differences in climate simulated in the pre-clearing and current experiments were analyzed for changes in Australian continental and regional climate to assess the modeled climate impacts of Australian land cover change. The changes in modeled climate were compared to observed changes in Australian precipitation over the last 50 and 100 years to assess whether modeled results could be detected in the historical record. The differences in climate simulation also were analyzed at the global scale to assess the impacts of local changes on larger scale circulation and climate at

  2. Integrated risk analysis of global climate change

    International Nuclear Information System (INIS)

    This paper discusses several factors that should be considered in integrated risk analyses of global climate change. We begin by describing how the problem of global climate change can be subdivided into largely independent parts that can be linked together in an analytically tractable fashion. Uncertainty plays a central role in integrated risk analyses of global climate change. Accordingly, we consider various aspects of uncertainty as they relate to the climate change problem. We also consider the impacts of these uncertainties on various risk management issues, such as sequential decision strategies, value of information, and problems of interregional and intergenerational equity. (author)

  3. Climate change and amphibians

    Directory of Open Access Journals (Sweden)

    Corn, P. S.

    2005-01-01

    Full Text Available Amphibian life histories are exceedingly sensitive to temperature and precipitation, and there is good evidence that recent climate change has already resulted in a shift to breeding earlier in the year for some species. There are also suggestions that the recent increase in the occurrence of El Niño events has caused declines of anurans in Central America and is linked to elevated mortality of amphibian embryos in the northwestern United States. However, evidence linking amphibian declines in Central America to climate relies solely on correlations, and the mechanisms underlying the declines are not understood. Connections between embryo mortality and declines in abundance have not been demonstrated. Analyses of existing data have generally failed to find a link between climate and amphibian declines. It is likely, however, that future climate change will cause further declines of some amphibian species. Reduced soil moisture could reduce prey species and eliminate habitat. Reduced snowfall and increased summer evaporation could have dramatic effects on the duration or occurrence of seasonal wetlands, which are primary habitat for many species of amphibians. Climate change may be a relatively minor cause of current amphibian declines, but it may be the biggest future challenge to the persistence of many species

  4. Climate change matters.

    Science.gov (United States)

    Macpherson, Cheryl Cox

    2014-04-01

    One manifestation of climate change is the increasingly severe extreme weather that causes injury, illness and death through heat stress, air pollution, infectious disease and other means. Leading health organisations around the world are responding to the related water and food shortages and volatility of energy and agriculture prices that threaten health and health economics. Environmental and climate ethics highlight the associated challenges to human rights and distributive justice but rarely address health or encompass bioethical methods or analyses. Public health ethics and its broader umbrella, bioethics, remain relatively silent on climate change. Meanwhile global population growth creates more people who aspire to Western lifestyles and unrestrained socioeconomic growth. Fulfilling these aspirations generates more emissions; worsens climate change; and undermines virtues and values that engender appreciation of, and protections for, natural resources. Greater understanding of how virtues and values are evolving in different contexts, and the associated consequences, might nudge the individual and collective priorities that inform public policy toward embracing stewardship and responsibility for environmental resources necessary to health. Instead of neglecting climate change and related policy, public health ethics and bioethics should explore these issues; bring transparency to the tradeoffs that permit emissions to continue at current rates; and offer deeper understanding about what is at stake and what it means to live a good life in today's world. PMID:23665996

  5. Climate variability and climate change vulnerability and adaptation. Workshop summary

    International Nuclear Information System (INIS)

    Representatives from fifteen countries met in Prague, Czech Republic, on September 11-15, 1995, to share results from the analysis of vulnerability and adaptation to global climate change. The workshop focused on the issues of global climate change and its impacts on various sectors of a national economy. The U.N. Framework Convention on Climate Change (FCCC), which has been signed by more than 150 governments worldwide, calls on signatory parties to develop and communicate measures they are implementing to respond to global climate change. An analysis of a country's vulnerability to changes in the climate helps it identify suitable adaptation measures. These analyses are designed to determine the extent of the impacts of global climate change on sensitive sectors such as agricultural crops, forests, grasslands and livestock, water resources, and coastal areas. Once it is determined how vulnerable a country may be to climate change, it is possible to identify adaptation measures for ameliorating some or all of the effects.The objectives of the vulnerability and adaptation workshop were to: The objectives of the vulnerability and adaptation workshop were to: Provide an opportunity for countries to describe their study results; Encourage countries to learn from the experience of the more complete assessments and adjust their studies accordingly; Identify issues and analyses that require further investigation; and Summarize results and experiences for governmental and intergovernmental organizations

  6. Applied climate-change analysis: the climate wizard tool.

    Directory of Open Access Journals (Sweden)

    Evan H Girvetz

    Full Text Available BACKGROUND: Although the message of "global climate change" is catalyzing international action, it is local and regional changes that directly affect people and ecosystems and are of immediate concern to scientists, managers, and policy makers. A major barrier preventing informed climate-change adaptation planning is the difficulty accessing, analyzing, and interpreting climate-change information. To address this problem, we developed a powerful, yet easy to use, web-based tool called Climate Wizard (http://ClimateWizard.org that provides non-climate specialists with simple analyses and innovative graphical depictions for conveying how climate has and is projected to change within specific geographic areas throughout the world. METHODOLOGY/PRINCIPAL FINDINGS: To demonstrate the Climate Wizard, we explored historic trends and future departures (anomalies in temperature and precipitation globally, and within specific latitudinal zones and countries. We found the greatest temperature increases during 1951-2002 occurred in northern hemisphere countries (especially during January-April, but the latitude of greatest temperature change varied throughout the year, sinusoidally ranging from approximately 50 degrees N during February-March to 10 degrees N during August-September. Precipitation decreases occurred most commonly in countries between 0-20 degrees N, and increases mostly occurred outside of this latitudinal region. Similarly, a quantile ensemble analysis based on projections from 16 General Circulation Models (GCMs for 2070-2099 identified the median projected change within countries, which showed both latitudinal and regional patterns in projected temperature and precipitation change. CONCLUSIONS/SIGNIFICANCE: The results of these analyses are consistent with those reported by the Intergovernmental Panel on Climate Change, but at the same time, they provide examples of how Climate Wizard can be used to explore regionally- and temporally

  7. Climate change and climate policy

    International Nuclear Information System (INIS)

    The climate issue is a great political and scientific challenge for several reasons: (1) There are many uncertain aspects of the climate problem, such as future emission of climate gases, the response of the climate system upon these gases, and the effects of climate changes. (2) It is probable, however, that anthropogenic emission of climate gases, deforestation etc. will cause noticeable climate changes in the future. This might be observed as increased frequency of extreme weather situations. This appears to be a greater threat than a gradual increase of temperature and precipitation. (3) Since the climate system is large and react only relatively slowly on changes in for instance the emission of climate gases, the climate problem can only be solved by means of long-term measures. (4) The climate changes may be irreversible. A rational short-term strategy is to ensure maximum flexibility, which can be done by ''slowing down'' (curtailing emissions) and by avoiding irreversible actions as much as possible. The long-term challenge is to develop an economically responsible alternative to the present fossil-based energy system that permits carbon-efficient technologies to compete on price with coal and unconventional oil and gas. Norway is in a special position by being a large exporter of fossil fuel and at the same time wanting to appear responsible in environmental matters. This combination may incur considerable expenses upon Norway and it is therefore important that environmental commitments like the Kyoto agreement can be honoured to the lowest possible cost. The costs can be minimized by: (1) minimizing the measure costs in Norway, (2) working to make the international quota price as low as possible, and (3) reducing the loss of petroleum income as much as possible. This report describes the earth's climate history, the forces behind climatic changes and what the prospects for the future look like. It also reviews what is being done to curtail the emission of

  8. Numerical Integration with Derivatives

    Institute of Scientific and Technical Information of China (English)

    Hu Cheng

    2006-01-01

    A new formula with derivatives for numerical integration was presented. Based on this formula and the Richardson extrapolation process, a numerical integration method was established. It can converge faster than the Romberg's. With the same accuracy, the computation of the new numerical integration with derivatives is only half of that of Romberg's numerical integration.

  9. From climate assessment to climate services

    OpenAIRE

    Visbeck, Martin

    2008-01-01

    The Intergovernmental Panel for Climate Change has convinced the public that climate change is real. To tackle it, the panel needs complementary climate services that provide continuous climate information for all regions and the globe.

  10. Climatic change

    International Nuclear Information System (INIS)

    This book proposes both a scientific and societal approach of a phenomenon which is today the object of lot of debates. Climates perception is illustrated with examples taken in various modern civilizations and in the history of mankind. The Sahara example illustrates the notion of climate evolution. The last chapters are devoted to forecasting and scenarios for the future, taking into account the share of uncertainty. The controversies generated by these forecasts and the Kyoto protocol stakes demonstrate the tight links between the scientific, economical and political aspects in climatic change debates. (J.S.)

  11. The determination of optimal climate policy

    International Nuclear Information System (INIS)

    Analyses of the costs and benefits of climate policy, such as the Stern Review, evaluate alternative strategies to reduce greenhouse gas emissions by requiring that the cost of emission cuts in each and every year has to be covered by the associated value of avoided damage, discounted by a an exogenously chosen rate. An alternative is to optimize abatement programmes towards a stationary state, where the concentrations of greenhouse gases are stabilized and shadow prices, including the rate of discount, are determined endogenously. This paper examines the properties of optimized stabilization. It turns out that the implications for the evaluation of climate policy are substantial if compared with evaluations of the present value of costs and benefits based on exogenously chosen shadow prices. Comparisons of discounted costs and benefits tend to exaggerate the importance of the choice of discount rate, while ignoring the importance of future abatement costs, which turns out to be essential for the optimal abatement path. Numerical examples suggest that early action may be more beneficial than indicated by comparisons of costs and benefits discounted by a rate chosen on the basis of current observations. (author)

  12. Probabilistic numerics and uncertainty in computations

    Science.gov (United States)

    Hennig, Philipp; Osborne, Michael A.; Girolami, Mark

    2015-01-01

    We deliver a call to arms for probabilistic numerical methods: algorithms for numerical tasks, including linear algebra, integration, optimization and solving differential equations, that return uncertainties in their calculations. Such uncertainties, arising from the loss of precision induced by numerical calculation with limited time or hardware, are important for much contemporary science and industry. Within applications such as climate science and astrophysics, the need to make decisions on the basis of computations with large and complex data have led to a renewed focus on the management of numerical uncertainty. We describe how several seminal classic numerical methods can be interpreted naturally as probabilistic inference. We then show that the probabilistic view suggests new algorithms that can flexibly be adapted to suit application specifics, while delivering improved empirical performance. We provide concrete illustrations of the benefits of probabilistic numeric algorithms on real scientific problems from astrometry and astronomical imaging, while highlighting open problems with these new algorithms. Finally, we describe how probabilistic numerical methods provide a coherent framework for identifying the uncertainty in calculations performed with a combination of numerical algorithms (e.g. both numerical optimizers and differential equation solvers), potentially allowing the diagnosis (and control) of error sources in computations. PMID:26346321

  13. State Wildlife Action Plans as Tools for Adapting to a Continuously Changing Climate

    Science.gov (United States)

    Metivier, D. W.; Yocum, H.; Ray, A. J.

    2015-12-01

    Public land management plans are potentially powerful policies for building sustainability and adaptive capacity. Land managers are recognizing the need to respond to numerous climate change impacts on natural and human systems. For the first time, in 2015, the federal government required each state to incorporate climate change into their State Wildlife Action Plans (SWAP) as a condition for funding. As important land management tools, SWAPs have the potential to guide state agencies in shaping and implementing practices for climate change adaptation. Intended to be revised every ten years, SWAPs can change as conditions and understanding of climate change evolves. This study asks what practices are states using to integrate climate change, and how does this vary between states? To answer this question, we conducted a broad analysis among seven states (CO, MT, NE, ND, SD, UT, WY) and a more in-depth analysis of four states (CO, ND, SD, WY). We use seven key factors that represent best practices for incorporating climate change identified in the literature. These best practices are species prioritization, key habitats, threats, monitoring, partnerships and participation, identification of management options, and implementation of management options. The in-depth analysis focuses on how states are using climate change information for specific habitats addressed in the plans. We find that states are integrating climate change in many different ways, showing varying degrees of sophistication and preparedness. We summarize different practices and highlight opportunities to improve the effectiveness of plans through: communication tools across state lines and stakeholders, explicit targeting of key habitats, enforcement and monitoring progress and success, and conducting vulnerability analyses that incorporate topics beyond climate and include other drivers, trajectories, and implications of historic and future land-use change.

  14. Effects of climate variation on winter cereal production in Spain

    OpenAIRE

    C. Rodríguez-Puebla; Ayuso, S. M.; Frías, M. D.; García-Casado, L. A.

    2007-01-01

    Climate variables responsible for inter-annual variations in the winter cereal yield in Spain were identified and climate information was translated into crop production. Empirical orthogonal functions and correlation analyses were applied to regional and large-scale climate variables to ascertain the links between climate and winter cereal yield. Interactions between climate and winter cereal productivity in Spain can be summarized as follows: the start of the growing season depends on minim...

  15. Decentralization and implementation of climate change policy in Uganda

    OpenAIRE

    Friis-Hansen, Esbern; Bashaasha, Bernard; Aben, Charles

    2013-01-01

    This working paper is the first of two working papers that presentings findings from the Climate Change and Rural Institutions (CCRI) research program on how meso-level institutions in Uganda are responding to climate change and extreme climate events. This working paper analyses national policies that to support climate change mitigation and adaptation and their implementation modalities. The second working paper focuses on the meso-level institutional dynamics of how climate change action i...

  16. The Impact of Climate Change on Tourism in Spain

    OpenAIRE

    Hein, Lars

    2007-01-01

    The tourism sector will be particularly affected by climate change, but there have been few studies specifying the impacts of climate change on tourism for a certain country. This paper considers the impacts of climate change on tourism in Spain. Tourism is a key economic sector in Spain, and it is strongly weather dependent. The paper analyses how the suitability of the Spanish climate for tourism will change, and how this will affect tourism flows to Spain. The suitability of the climate fo...

  17. Habitable Climates

    CERN Document Server

    Spiegel, David S; Scharf, Caleb A

    2007-01-01

    The Earth is only partially habitable according to the standard liquid-water definition. We reconsider planetary habitability in the framework of energy-balance models, the simplest seasonal models in physical climatology, to assess the spatial and temporal habitability of Earth-like planets. In order to quantify the degree of climatic habitability of our models, we define several metrics of fractional habitability. Previous evaluations of habitable zones may have omitted important climatic conditions by focusing on close Solar System analogies. For example, we find that model pseudo-Earths with different rotation rates or different land-ocean fractions generally have fractional habitabilities that differ significantly from that of the Earth itself. Furthermore, the stability of a planet's climate against albedo-feedback snowball events strongly impacts its habitability. Therefore, issues of climate dynamics may be central in assessing the habitability of discovered terrestrial exoplanets, especially if astro...

  18. Climate catastrophes

    Science.gov (United States)

    Budyko, Mikhail

    1999-05-01

    Climate catastrophes, which many times occurred in the geological past, caused the extinction of large or small populations of animals and plants. Changes in the terrestrial and marine biota caused by the catastrophic climate changes undoubtedly resulted in considerable fluctuations in global carbon cycle and atmospheric gas composition. Primarily, carbon dioxide and other greenhouse gas contents were affected. The study of these catastrophes allows a conclusion that climate system is very sensitive to relatively small changes in climate-forcing factors (transparency of the atmosphere, changes in large glaciations, etc.). It is important to take this conclusion into account while estimating the possible consequences of now occurring anthropogenic warming caused by the increase in greenhouse gas concentration in the atmosphere.

  19. Climatic change

    International Nuclear Information System (INIS)

    In spite of man's remarkable advances in technology, ultimately he is still dependent on the Earth's climatic system for food and fresh water. The recent occurrences in certain regions of the world of climatic extremes such as excessive rain or droughts and unseasonably high or low temperatures have led to speculation that a major climatic change is occurring on a global scale. Some point to the recent drop in temperatures in the northern hemisphere as an indication that the Earth is entering a new ice age. Others see a global warming trend that may be due to a build-up of carbon dioxide in the atmosphere. An authoritative report on the subject has been prepared by a World Meteorological Organization Panel of Experts on Climatic Change. Excerpts from the report are given. (author)

  20. Climate Reconstructions

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The NOAA Paleoclimatology Program archives reconstructions of past climatic conditions derived from paleoclimate proxies, in addition to the Program's large...

  1. Climate engineering

    OpenAIRE

    Platt, Ulrich

    2014-01-01

    Es klingt wie eine Mischung aus Größenwahn und Science Fiction: Wissenschaftler wollen das Klima mit Hightechverfahren beeinflussen. "Climate engineering" heißt der Fachbegriff. Natürlich geht es dabei nicht um den verregneten Sommer, sondern um den globalen Klimawandel. Campus-Reporter Nils Birschmann hat sich bei den Umweltforschern der Uni Heidelberg umgehört, ob was dran ist am "climate engineering". Der Beitrag erschien in der Sendereihe "Campus-Report" - einer Beitragsreihe, in ...

  2. Energy & Climate: Getting Quantitative

    Science.gov (United States)

    Wolfson, Richard

    2011-11-01

    A noted environmentalist claims that buying an SUV instead of a regular car is energetically equivalent to leaving your refrigerator door open for seven years. A fossil-fuel apologist argues that solar energy is a pie-in-the-sky dream promulgated by na"ive environmentalists, because there's nowhere near enough solar energy to meet humankind's energy demand. A group advocating shutdown of the Vermont Yankee nuclear plant claims that 70% of its electrical energy is lost in transmission lines. Around the world, thousands agitate for climate action, under the numerical banner ``350.'' Neither the environmentalist, the fossil-fuel apologist, the antinuclear activists, nor most of those marching under the ``350'' banner can back up their assertions with quantitative arguments. Yet questions about energy and its environmental impacts almost always require quantitative answers. Physics can help! This poster gives some cogent examples, based on the newly published 2^nd edition of the author's textbook Energy, Environment, and Climate.

  3. Climatic change. What solutions?

    International Nuclear Information System (INIS)

    From 1990 to the present day, worldwide greenhouse gas emissions have increased by about 25%. Fighting climatic change has become an urgency: we only have 15 years in front of us to inflect the trajectory of worldwide emissions and to avoid a temperature rise of more than 2 deg. C during this century. Therefore, how is it possible to explain the shift between the need of an urgent action and the apparent inertia of some governing parties? How is it possible to implement a worldwide governance capable to answer the urgency of the fight against climatic change? These are the two questions that this pedagogical and concrete book tries to answer by analysing the different dimensions of climatic change and by making a first status of the building up of the international action, and in particular of the Kyoto protocol. For the post-2012 era, research and negotiations are in progress with the objective of reaching an agreement for the Copenhagen conference of December 2009. Several architectures are possible. This book shades light on the advantages and limitations of each of them with the possible compromises. It supplies a pluri-disciplinary approach of the international negotiations, often considered as complex by the general public. Content: 1 - understanding the climatic change stakes: climatic stakes, the main actors behind the figures, the technical-economical stakes; 2 - understanding the present day architecture of the fight against climatic change: strengths and weaknesses of the Kyoto protocol; encouraging research and technology spreading; the other action means in developing countries; 3 - what structure for a future international agreement?: the Bali negotiation process; the ideal vision: an improved Kyoto protocol; the pragmatic vision: individualized commitments; the negotiation space; preventing a planned fiasco. (J.S.)

  4. Changing climate, changing frames

    International Nuclear Information System (INIS)

    Highlights: ► We show development of flood policy frames in context of climate change attention. ► Rising attention on climate change influences traditional flood policy framing. ► The new framing employs global-scale scientific climate change knowledge. ► With declining attention, framing disregards climate change, using local knowledge. ► We conclude that frames function as sensemaking devices selectively using knowledge. -- Abstract: Water management and particularly flood defence have a long history of collective action in low-lying countries like the Netherlands. The uncertain but potentially severe impacts of the recent climate change issue (e.g. sea level rise, extreme river discharges, salinisation) amplify the wicked and controversial character of flood safety policy issues. Policy proposals in this area generally involve drastic infrastructural works and long-term investments. They face the difficult challenge of framing problems and solutions in a publicly acceptable manner in ever changing circumstances. In this paper, we analyse and compare (1) how three key policy proposals publicly frame the flood safety issue, (2) the knowledge referred to in the framing and (3) how these frames are rhetorically connected or disconnected as statements in a long-term conversation. We find that (1) framings of policy proposals differ in the way they depict the importance of climate change, the relevant timeframe and the appropriate governance mode; (2) knowledge is selectively mobilised to underpin the different frames and (3) the frames about these proposals position themselves against the background of the previous proposals through rhetorical connections and disconnections. Finally, we discuss how this analysis hints at the importance of processes of powering and puzzling that lead to particular framings towards the public at different historical junctures

  5. Climate shocks: natural and anthropogenic

    International Nuclear Information System (INIS)

    The impact of multiple nuclear explosions in the earth atmosphere on global climate is explored, summarizing the results of recent theoretical modeling studies. Two natural analogs, the greenhouse effect and a major volcanic explosion, are analyzed; and particular attention is then given to data on the climatic effects of previous atmospheric tests of nuclear weapons, numerical models of these effects, and the effect of the Tunguska meteor fall of 1908 on the ozone layer and climate. It is concluded that, although the current models contain many uncertainties, multiple nuclear explosions would doubtless produce catastrophic changes, much more serious than those which would result from a doubling of the present CO2 content. Strong temporal and spatial variabilities of climate would exclude normal life or industrial activity on the planet. 110 references

  6. Integrated climate and hydrology modelling

    DEFF Research Database (Denmark)

    Larsen, Morten Andreas Dahl

    global warming and increased frequency of extreme events. The skill in developing projections of both the present and future climate depends essentially on the ability to numerically simulate the processes of atmospheric circulation, hydrology, energy and ecology. Previous modelling efforts of climate...... existing climate and hydrology models to more directly include the interaction between the atmosphere and the land surface. The present PhD study is motivated by an ambition of developing and applying a modelling tool capable of including the interaction and feedback mechanisms between the atmosphere and...... the land surface. The modelling tool consists of a fully dynamic two-way coupling of the HIRHAM regional climate model and the MIKE SHE hydrological model. The expected gain is twofold. Firstly, HIRHAM utilizes the land surface component of the combined MIKE SHE/SWET hydrology and land surface model...

  7. Projection of future climate changes

    International Nuclear Information System (INIS)

    Climate models provide the opportunity to anticipate how the climate system may change due to anthropogenic activities during the 21. century. Studies are based on numerical simulations that explore the evolution of the mean climate and its variability according to different socio-economic scenarios. We present a selection of results from phase 5 of the Climate model intercomparison project (CMIP5) with an illustrative focus on the two French models that participated to this exercise. We describe the effects of human perturbations upon surface temperature, precipitation, the cryo-sphere, but also extreme weather events and the carbon cycle. Results show a number of robust features, on the amplitude and geographical patterns of the expected changes and on the processes at play in these changes. They also show the limitations of such a prospective exercise and persistent uncertainties on some key aspects. (authors)

  8. Long-term phyto-, ornitho- and ichthyophenological time-series analyses in Estonia

    Science.gov (United States)

    Ahas, Rein

    This study analyzes a long-term phenological time series for the impact assessment of climate changes on Estonian nature and for the methodological study of the possible limitations of using phenological time series for climate trend analyses. These limiting factors can influence the results of studies more than the real impact of climate changes, which may have a much smaller numeric value. The 132-year series of the arrival of the skylark (Alauda arvensis) and the white wagtail (Motacilla alba), the 78-year series of the blossoming of the wood anemone (Anemone nemorosa), the bird cherry (Padus racemosa), apple trees (Malus domestica) and lilacs (Syringa vulgaris), and the 44-year series of the spawning of pike (Esox lucius) and bream (Abramis brama) were studied at three selected observation points in Estonia. The study of the phenological time series shows that Estonian springs have, on the basis of the database, advanced 8 days on average over the last 80-year period; the last 40-year period has warmed even faster.

  9. Climate Mobile: A Climate Education App For Everyone

    Science.gov (United States)

    Yunck, T. P.

    2011-12-01

    There exists a vast and energetic community of non-scientists concerned about climate change and engaged in exploring how they can contribute to our collective response. There are also many, equally energetic, who question the scientific consensus on climate change. To professionals who follow the debates it is plain that few non-scientists possess up-to-date climate information, or the means to make meaningful use of such information as can be found scattered across the internet. To remedy this GeoOptics Inc. has developed, as a spinoff of NASA's "Climate Virtual Observatory," an educational iPhone app called Climate Mobile, aka "CliMate." It allows users to call up the latest information on global surface and atmospheric temperatures and trends, Arctic ice cover, weather, atmospheric CO2 concentrations, and solar activity, along with IPCC climate forecasts and tutorials on climate change, space weather, greenhouse warming, and other subjects. Two advanced tools, the Climate Analyzer and the Sensor Data Comparator, allow the citizen-scientist to explore climate data in greater depth. The Analyzer offers access to the 130-year global surface temperature data from NOAA/NCDC and NASA/GISS, and the 32-year atmospheric temperature record from the MSU and AMSU instruments on NOAA satellites. Users can examine data for the full globe, or partitioned by N/S hemisphere or land and ocean and can filter, plot and compare the data over any desired interval, using smoothing windows ranging from 1 month to 15 years. The Comparator allows users to compare atmospheric temperature data from AIRS, GPS radio occultation, and ECMWF global analyses both regionally and globally, and compute instrumental biases and sigmas under different filtering strategies to better understand the inherent properties of each. With these tools users can generate and view plots, tailor the plot characteristics, save the results, or send them to a URL or email address. To illustrate the utility of the

  10. Climate and isotopic tracers

    International Nuclear Information System (INIS)

    The applications of natural radioactivity and isotopic measurements in the sciences concerning Earth and its atmosphere, are numerous: carbon 14 dating with the Tandetron apparatus at the Cea, measurement of oxygen 18 in coral or sediment limestone for the determination of ocean temperature and salinity, carbon 14 dating of corals for the determination of sea level variations, deuterium content in polar ice-cap leads to temperature variations determination; isotopic measurements also enable the determination of present climate features such as global warming, oceanic general circulation

  11. Coexistence, Classroom Climate and Philosophy for Children

    OpenAIRE

    Gonzalo Romero Izarra; Amparo Caballero González

    2008-01-01

    In this paper we analyse the relationship between the classroom’s social climate and the general climate of society in which the school is inserted. We consider essential to start from this reflection in order to define an educational process for social transformation. Philosophy for Children is a methodological option to improve this social climate as it offers teachers and pupils a potentially transforming work that deepens into the values of human relationships for people who are concerned...

  12. Investing in Climate Change. Dutch Banks Compared

    International Nuclear Information System (INIS)

    This report is the first comparison of the climate change performance of Dutch banks that analyses the actual investments of these banks. It reviews a substantial share of each bank's portfolio, according to three criteria: how much they invest in the main cause of climate change, fossil fuels; how much they invest in the main alternative to fossil fuels, renewable energy; the bank's plans and policies to limit their contribution to climate change

  13. Present-day climatic equivalents of European Cenozoic climates

    Science.gov (United States)

    Utescher, Torsten; Mosbrugger, Volker; Ivanov, Dimiter; Dilcher, David L.

    2009-07-01

    Recently, continental climate evolution in Central Europe over the last 45 Ma has been reconstructed from the palaeobotanical record using a Nearest Living Relative methodology (Coexistence Approach; CA). The reconstructed climate curves document in detail the transition from almost tropical conditions in the Mid-Eocene to a temperate climate at the Pliocene/Pleistocene transition. The observed climatic shifts are primarily expressed as non-proportional changes of the different variables taken into account. In the present study a published palaeoclimate data set for a total of 42 macrofloras complemented by new calculations is used as base to analyse the climatic space in which a fossil flora existed. To define these spaces CA intervals calculated for 3 temperature (mean annual temperature, cold and warm month mean) and 3 precipitation variables (mean annual precipitation, mean monthly precipitation of the driest and of the wettest month) are combined. Using a global gridded climatology (10' resolution), this climate space is then utilized to identify Recent climate analogues with respect to the variables regarded. For 18 macrofloras climatic analogue regions with respect to 6 variables are identified on the globe. For 16 macrofloras, analogues exist when three temperature parameters and mean annual precipitation are regarded. No Recent equivalents are found in 8 cases. This corroborates the assumption of the temporary existence of non-analogue climates in the Cenozoic. As shown by multivariate statistics the observed anomalies with respect to present-day conditions basically refer to high winter temperatures. Deploying a GIS, the Recent climate analogues can be presented as sets of grid cells for each flora that can be mapped on a globe. Once identified, these regions can be merged with adequate thematic layers to assess additional proxy data for the palaeofloras. To exemplify the procedure Koeppen climate type, numbers of days with ground frost, as well as

  14. The climate myth

    International Nuclear Information System (INIS)

    The apparent consensus of opinion about the human responsibility in the climate crisis is crumbling down. This book presents a sceptical point of view about the link between global warming and the anthropic carbon dioxide emissions. Targeting his critics on some key-points, the author explains with simple words the weaknesses of some arguments, in particular the statistical ones, that have been considered as conclusive: historical reconstruction of global ambient temperatures, ice cores analysis, climate models reliability.. Behind these particular deficiencies emerges a deeper epistemological question involving the real nature of carbon-related theories. By comparing the present day climate hypothesis to other episodes of the sciences history, the author advances that we are again in presence of a new case of 'pathological science'. Finally, he calls our attention on the insidious trend of some scientifical talks which is to consider the Earth as a subject instead of an object. The importance of the political, economical and social stakes of the climate debate imposes that we give a particular attention to these analyses. (J.S.)

  15. Periodic safety analyses

    International Nuclear Information System (INIS)

    The IAEA Safety Guide 50-SG-S8 devoted to 'Safety Aspects of Foundations of Nuclear Power Plants' indicates that operator of a NPP should establish a program for inspection of safe operation during construction, start-up and service life of the plant for obtaining data needed for estimating the life time of structures and components. At the same time the program should ensure that the safety margins are appropriate. Periodic safety analysis are an important part of the safety inspection program. Periodic safety reports is a method for testing the whole system or a part of the safety system following the precise criteria. Periodic safety analyses are not meant for qualification of the plant components. Separate analyses are devoted to: start-up, qualification of components and materials, and aging. All these analyses are described in this presentation. The last chapter describes the experience obtained for PWR-900 and PWR-1300 units from 1986-1989

  16. Laser Beam Focus Analyser

    DEFF Research Database (Denmark)

    Nielsen, Peter Carøe; Hansen, Hans Nørgaard; Olsen, Flemming Ove;

    2007-01-01

    The quantitative and qualitative description of laser beam characteristics is important for process implementation and optimisation. In particular, a need for quantitative characterisation of beam diameter was identified when using fibre lasers for micro manufacturing. Here the beam diameter limits...... the obtainable features in direct laser machining as well as heat affected zones in welding processes. This paper describes the development of a measuring unit capable of analysing beam shape and diameter of lasers to be used in manufacturing processes. The analyser is based on the principle of a rotating...... mechanical wire being swept through the laser beam at varying Z-heights. The reflected signal is analysed and the resulting beam profile determined. The development comprised the design of a flexible fixture capable of providing both rotation and Z-axis movement, control software including data capture...

  17. Report sensory analyses veal

    OpenAIRE

    Veldman, M.; Schelvis-Smit, A.A.M.

    2005-01-01

    On behalf of a client of Animal Sciences Group, different varieties of veal were analyzed by both instrumental and sensory analyses. The sensory evaluation was performed with a sensory analytical panel in the period of 13th of May and 31st of May, 2005. The three varieties of veal were: young bull, pink veal and white veal. The sensory descriptive analyses show that the three groups Young bulls, pink veal and white veal, differ significantly in red colour for the raw meat as well as the baked...

  18. Climate certificates

    International Nuclear Information System (INIS)

    Reduced emissions of climate gases at the lowest cost require international cooperation in order to ensure that the most cost-efficient measures are taken. A market for emission rights is one way of achieving this. However, creating the right conditions for such a market to operate requires an unambiguous definition of the product to be traded. In this PM, the Swedish Power Association sketches out how such a product could be defined, and how a market for the resulting unambiguously defined product could be operated internationally, in parallel with other markets for energy products. Trade in climate certificates could become a joint EU approach to achieving common results within the field of climate policy. The main features of the proposal are as follows: Electricity producers would be allowed to issue climate certificates for electricity produced without climate-affecting emissions, e.g. in wind power plants. 1 kWh of electricity produced without emissions would entitle the utility to issue a climate certificate for 1 kWh. Electricity from power stations having low emissions, e.g. modern natural gas-fired plants, would entitle the utility to issue certificates in proportion to how much lower their emissions were in comparison with those from conventional coal-fired power stations. The number of certificates would be reduced by an individual coefficient, related directly to the quantity of climate-affecting emissions from the plant concerned. They would be traded and noted on markets in the various member countries. The certificates would not be nationally restricted, but could be traded across borders. Exchanges would be authorised by national authorities, in accordance with overall EU directives. These authorised exchanges would act as certification bodies, checking that certificates had been properly issued in accordance with a corresponding volume of electricity production. Electricity and certificates could be purchased from different suppliers. The

  19. Introduction to numerical mathematics

    CERN Document Server

    Stiefel, Eduard L

    1963-01-01

    An Introduction to Numerical Mathematics provides information pertinent to the fundamental aspects of numerical mathematics. This book covers a variety of topics, including linear programming, linear and nonlinear algebra, polynomials, numerical differentiation, and approximations.Organized into seven chapters, this book begins with an overview of the solution of linear problems wherein numerical mathematics provides very effective algorithms consisting of finitely many computational steps. This text then examines the method for the direct solution of a definite problem. Other chapters conside

  20. Analysing Interconnectivity among Economies

    OpenAIRE

    Alfred Wong; Tom Fong

    2010-01-01

    As international financial integration gathers pace, interconnectivity has increased tremendously among financial institutions, financial markets and financial systems, a phenomenon to which the recent global financial crisis perhaps provided the best testimony. The interconnectivity among financial entities at various levels is multilateral in dimension and highly complicated with numerous feedback loops. To contribute to the understanding of the complexity of the global financial system, th...

  1. Wavelet Analyses and Applications

    Science.gov (United States)

    Bordeianu, Cristian C.; Landau, Rubin H.; Paez, Manuel J.

    2009-01-01

    It is shown how a modern extension of Fourier analysis known as wavelet analysis is applied to signals containing multiscale information. First, a continuous wavelet transform is used to analyse the spectrum of a nonstationary signal (one whose form changes in time). The spectral analysis of such a signal gives the strength of the signal in each…

  2. Probabilistic safety analyses (PSA)

    International Nuclear Information System (INIS)

    The guide shows how the probabilistic safety analyses (PSA) are used in the design, construction and operation of light water reactor plants in order for their part to ensure that the safety of the plant is good enough in all plant operational states

  3. Deactivations during the numerical processing

    Institute of Scientific and Technical Information of China (English)

    FENG HongBo; ZHANG Ye; TANG YiYuan; JIN Jing; DONG Feng; FENG ShiGang; ZHANG WuTian

    2007-01-01

    Deactivation has been encountered frequently in functional brain imaging researches. However,the deactivations during the numerical processing have not been reported yet. In this study,the functional magnetic resonance imaging (fMRI) was employed to investigate the pattern of the deactivation in the brain of 15 healthy subjects during the numerical addition task. Analyses revealed significant deactivations in several brain regions,including the posterior cingulate,precuneus,anterior cingulate and prefrontal cortex. Especially,we found notable deactivation in bilateral insula. Accounting for the cognitive functions of these regions participating in a combinated way,we discuss their contributions in sustaining the brain activity during conscious resting state,and indicate that the insula is an important area of gathering auditory information from the external world.

  4. Temperate climate - Innovative outputs nexus

    NARCIS (Netherlands)

    Coccia, M.

    2014-01-01

    Technological change is a vital human activity that interacts with geographic factors and environment. The purpose of the study here is to analyse the relationship between geo-climate zones of the globe and technological outputs in order to detect favourable areas that spur higher technological chan

  5. Universal Numeric Segmented Display

    CERN Document Server

    Azad, Md Abul kalam; Kamruzzaman, S M

    2010-01-01

    Segmentation display plays a vital role to display numerals. But in today's world matrix display is also used in displaying numerals. Because numerals has lots of curve edges which is better supported by matrix display. But as matrix display is costly and complex to implement and also needs more memory, segment display is generally used to display numerals. But as there is yet no proposed compact display architecture to display multiple language numerals at a time, this paper proposes uniform display architecture to display multiple language digits and general mathematical expressions with higher accuracy and simplicity by using a 18-segment display, which is an improvement over the 16 segment display.

  6. Climate change

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2006-07-01

    This paper presented indicators of climate change for British Columbia (BC) with an emphasis on the coastal region. An overview of global effects of climate change was presented, as well as details of BC's current climate change action plan. Indicators examined in the paper for the BC coastal region included long-term trends in air temperature; long-term trends in precipitation; coastal ocean temperatures; sea levels on the BC coast; and the sensitivity of the BC coast to sea level rise and erosion. Data suggested that average air temperatures have become higher in many areas, and that Springtime temperatures have become warmer over the whole province. Winters have become drier in many areas of the province. Sea surface temperature has risen over the entire coast, with the North Coast and central Strait of Georgia showing the largest increases. Deep-water temperatures have also increased in 5 inlets on the South Coast. Results suggested that the direction and spatial pattern of the climate changes reported for British Columbia are consistent with broader trends in North America and the type of changes predicted by climate models for the region. Climate change will likely result in reduced snow-pack in southern BC. An earlier spring freshet on many snow-dominated river systems is anticipated as well as glacial retreat and disappearance. Warmer temperatures in some lakes and rivers are expected, as well as the increased frequency and severity of natural disturbances such as the pine mountain beetle. Large-scale shifts in ecosystems and the loss of certain ecosystems may also occur. BC's current climate plan includes cost effective actions that address GHG emissions and support efficient infrastructure and opportunities for innovation. Management programs for forest and agricultural lands have been initiated, as well as programs to reduce emissions from government operations. Research is also being conducted to understand the impacts of climate change on

  7. Climate change

    International Nuclear Information System (INIS)

    This paper presented indicators of climate change for British Columbia (BC) with an emphasis on the coastal region. An overview of global effects of climate change was presented, as well as details of BC's current climate change action plan. Indicators examined in the paper for the BC coastal region included long-term trends in air temperature; long-term trends in precipitation; coastal ocean temperatures; sea levels on the BC coast; and the sensitivity of the BC coast to sea level rise and erosion. Data suggested that average air temperatures have become higher in many areas, and that Springtime temperatures have become warmer over the whole province. Winters have become drier in many areas of the province. Sea surface temperature has risen over the entire coast, with the North Coast and central Strait of Georgia showing the largest increases. Deep-water temperatures have also increased in 5 inlets on the South Coast. Results suggested that the direction and spatial pattern of the climate changes reported for British Columbia are consistent with broader trends in North America and the type of changes predicted by climate models for the region. Climate change will likely result in reduced snow-pack in southern BC. An earlier spring freshet on many snow-dominated river systems is anticipated as well as glacial retreat and disappearance. Warmer temperatures in some lakes and rivers are expected, as well as the increased frequency and severity of natural disturbances such as the pine mountain beetle. Large-scale shifts in ecosystems and the loss of certain ecosystems may also occur. BC's current climate plan includes cost effective actions that address GHG emissions and support efficient infrastructure and opportunities for innovation. Management programs for forest and agricultural lands have been initiated, as well as programs to reduce emissions from government operations. Research is also being conducted to understand the impacts of climate change on water

  8. Organizational Climate for Successful Aging.

    Science.gov (United States)

    Zacher, Hannes; Yang, Jie

    2016-01-01

    Research on successful aging at work has neglected contextual resources such as organizational climate, which refers to employees' shared perceptions of their work environment. We introduce the construct of organizational climate for successful aging (OCSA) and examine it as a buffer of the negative relationship between employee age and focus on opportunities (i.e., beliefs about future goals and possibilities at work). Moreover, we expected that focus on opportunities, in turn, positively predicts job satisfaction, organizational commitment, and motivation to continue working after official retirement age. Data came from 649 employees working in 120 companies (M age = 44 years, SD = 13). We controlled for organizational tenure, psychological climate for successful aging (i.e., individuals' perceptions), and psychological and organizational age discrimination climate. Results of multilevel analyses supported our hypotheses. Overall, our findings suggest that OCSA is an important contextual resource for successful aging at work. PMID:27458405

  9. Advance in Application of Regional Climate Models in China

    Institute of Scientific and Technical Information of China (English)

    ZHANG Wei; YAN Minhua; CHEN Panqin; XU Helan

    2008-01-01

    Regional climate models have become the powerful tools for simulating regional climate and its changeprocess and have been widely used in China. Using regional climate models, some research results have been obtainedon the following aspects: 1) the numerical simulation of East Asian monsoon climate, including exceptional monsoonprecipitation, summer precipitation distribution, East Asian circulation, multi-year climate average condition, summerrain belt and so on; 2) the simulation of arid climate of the western China, including thermal effect of the Qing-hai-Tibet Plateau, the plateau precipitation in the Qilian Mountains; and the impacts of greenhouse effects (CO2 dou-bling) upon climate in the western China; and 3) the simulation of the climate effect of underlying surface changes, in-cluding the effect of soil on climate formation, the influence of terrain on precipitation, the effect of regional soil deg-radation on regional climate, the effect of various underlying surfaces on regional climate, the effect of land-sea con-trast on the climate formulation, the influence of snow cover over the plateau regions on the regional climate, the effectof vegetation changes on the regional climate, etc. In the process of application of regional climate models, the prefer-ences of the models are improved so that better simulation results are gotten. At last, some suggestions are made aboutthe application of regional climate models in regional climate research in the future.

  10. Climatic controls on diffuse groundwater recharge across Australia

    OpenAIRE

    Barron, O. V.; R. S. Crosbie; W. R. Dawes; S. P. Charles; T. Pickett; M. J. Donn

    2012-01-01

    Reviews of field studies of groundwater recharge have attempted to investigate how climate characteristics control recharge, but due to a lack of data have not been able to draw any strong conclusions beyond that rainfall is the major determinant. This study has used numerical modelling for a range of Köppen-Geiger climate types (tropical, arid and temperate) to investigate the effect of climate variables on recharge for different soil and vegetation types. For the majority of climate types, ...

  11. Climatic controls on diffuse groundwater recharge across Australia

    OpenAIRE

    Barron, O. V.; R. S. Crosbie; D. Pollock; W. R. Dawes; S. P. Charles; T. Pickett; M. Donn

    2012-01-01

    Reviews of field studies of groundwater recharge have attempted to investigate how climate characteristics control recharge, but due to a lack of data have not been able to draw any strong conclusions beyond that rainfall is the major determinant. This study has used numerical modeling for a range of Köppen-Geiger climate types (tropical, arid and temperate) to investigate the effect of climate variables on recharge for different soil and vegetation types. For the majority of climate t...

  12. Challenges in combining projections from multiple climate models

    OpenAIRE

    J. Cermak; Furrer, R.; Knutti, R.; Meehl, G. A.; Tebaldi, C.

    2010-01-01

    Recent coordinated efforts, in which numerous general circulation climate models have been run for a common set of experiments, have produced large datasets of projections of future climate for various scenarios. Those multimodel ensembles sample initial conditions, parameters, and structural uncertainties in the model design, and they have prompted a variety of approaches to quantifying uncertainty in future climate change. International climate change assessments also rely heavily on these ...

  13. Norwegian climate research. An evaluation

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2012-06-15

    [English] In early 2011, the Norwegian Research Council (RCN) appointed a committee to review Norwegian climate research. The aim of the evaluation was to provide a critical review of Norwegian climate research in an international perspective and to recommend measures to enhance the quality, efficiency and relevance of future climate research. The Evaluation Committee met three times: in August and December 2011, and March 2012. RCN sent an invitation to 140 research organisations to participate by delivering background information on their climate research. Based on the initial response, 48 research units were invited to submit self-assessments and 37 research units responded. These were invited to hearings during the second meeting of the Evaluation Committee in December. In our judgement, a great majority of the most active research units are covered by this evaluation report. It should be emphasised that the evaluation concerned the Norwegian landscape of climate research rather than individual scientists or research units. Bibliometric analyses and social network analyses provided additional information. We are aware of problems in making comparisons across disciplinary publishing traditions, especially with regard to the differences between the natural and social sciences and the humanities. The Evaluation Committee also reviewed a number of governmental and RCN policy documents and conducted interviews with the chairs of the NORKLIMA Programme Steering Board and the Norwegian IPY Committee, as well as with staff members of RCN. Additional information was received from hearings organised by RCN with the science communities and various stakeholders in January 2012. For the purpose of this evaluation, climate research was divided into three broad thematic areas: 1. The climate system and climate change: research on climate variability and change in order to improve our capability of understanding climate and of projecting climate change for different time

  14. Possible future HERA analyses

    CERN Document Server

    Geiser, Achim

    2015-01-01

    A variety of possible future analyses of HERA data in the context of the HERA data preservation programme is collected, motivated, and commented. The focus is placed on possible future analyses of the existing $ep$ collider data and their physics scope. Comparisons to the original scope of the HERA programme are made, and cross references to topics also covered by other participants of the workshop are given. This includes topics on QCD, proton structure, diffraction, jets, hadronic final states, heavy flavours, electroweak physics, and the application of related theory and phenomenology topics like NNLO QCD calculations, low-x related models, nonperturbative QCD aspects, and electroweak radiative corrections. Synergies with other collider programmes are also addressed. In summary, the range of physics topics which can still be uniquely covered using the existing data is very broad and of considerable physics interest, often matching the interest of results from colliders currently in operation. Due to well-e...

  15. Statistisk analyse med SPSS

    OpenAIRE

    Linnerud, Kristin; Oklevik, Ove; Slettvold, Harald

    2004-01-01

    Dette notatet har sitt utspring i forelesninger og undervisning for 3.års studenter i økonomi og administrasjon ved høgskolen i Sogn og Fjordane. Notatet er særlig lagt opp mot undervisningen i SPSS i de to kursene ”OR 685 Marknadsanalyse og merkevarestrategi” og ”BD 616 Økonomistyring og analyse med programvare”.

  16. Prospective analysis of beyond Kyoto climate policy: a sequential game framework

    International Nuclear Information System (INIS)

    This article proposes a sequential game methodology to analyse the long-term climate policy prospects. Players can sequentially choose the best policy, among a series of policy options, while reacting to past moves of the other players. In order to illustrate the game methodology, a numerical optimisation exercise is made, based on a simple integrated assessment model. The non-cooperative equilibrium arising from a five-stage sequential game with two large players (Annex B and non-Annex B regions), which tries to replicate the Kyoto and beyond Kyoto scenarios, is studied

  17. ADMINISTRATIVE CLIMATE.

    Science.gov (United States)

    BRUCE, ROBERT L.; CARTER, G.L., JR.

    IN THE COOPERATIVE EXTENSION SERVICE, STYLES OF LEADERSHIP PROFOUNDLY AFFECT THE QUALITY OF THE SERVICE RENDERED. ACCORDINGLY, MAJOR INFLUENCES ON ADMINISTRATIVE CLIMATE AND EMPLOYEE PRODUCTIVITY ARE EXAMINED IN ESSAYS ON (1) SOURCES OF JOB SATISFACTION AND DISSATISFACTION, (2) MOTIVATIONAL THEORIES BASED ON JOB-RELATED SATISFACTIONS AND NEEDS,…

  18. Correcting Numerical Simulations for Known Expectations

    OpenAIRE

    Myerscough, K.W.

    2015-01-01

    Predictions of the future climate require long-time simulation of a chaotic dynamical system. This poses a challenge for numerical simulations, as these do not necessarily capture the correct long-term behaviour of chaotic systems. This problem is exacerbated by the wide range of length scales present in atmospheric and oceanic dynamics. The modeling choices for small scale processes have a large impact on long term statistics of the scales of interest. This thesis studies the dynamics of two...

  19. Uncertainty quantification and validation of combined hydrological and macroeconomic analyses.

    Energy Technology Data Exchange (ETDEWEB)

    Hernandez, Jacquelynne; Parks, Mancel Jordan; Jennings, Barbara Joan; Kaplan, Paul Garry; Brown, Theresa Jean; Conrad, Stephen Hamilton

    2010-09-01

    Changes in climate can lead to instabilities in physical and economic systems, particularly in regions with marginal resources. Global climate models indicate increasing global mean temperatures over the decades to come and uncertainty in the local to national impacts means perceived risks will drive planning decisions. Agent-based models provide one of the few ways to evaluate the potential changes in behavior in coupled social-physical systems and to quantify and compare risks. The current generation of climate impact analyses provides estimates of the economic cost of climate change for a limited set of climate scenarios that account for a small subset of the dynamics and uncertainties. To better understand the risk to national security, the next generation of risk assessment models must represent global stresses, population vulnerability to those stresses, and the uncertainty in population responses and outcomes that could have a significant impact on U.S. national security.

  20. Biomass feedstock analyses

    Energy Technology Data Exchange (ETDEWEB)

    Wilen, C.; Moilanen, A.; Kurkela, E. [VTT Energy, Espoo (Finland). Energy Production Technologies

    1996-12-31

    The overall objectives of the project `Feasibility of electricity production from biomass by pressurized gasification systems` within the EC Research Programme JOULE II were to evaluate the potential of advanced power production systems based on biomass gasification and to study the technical and economic feasibility of these new processes with different type of biomass feed stocks. This report was prepared as part of this R and D project. The objectives of this task were to perform fuel analyses of potential woody and herbaceous biomasses with specific regard to the gasification properties of the selected feed stocks. The analyses of 15 Scandinavian and European biomass feed stock included density, proximate and ultimate analyses, trace compounds, ash composition and fusion behaviour in oxidizing and reducing atmospheres. The wood-derived fuels, such as whole-tree chips, forest residues, bark and to some extent willow, can be expected to have good gasification properties. Difficulties caused by ash fusion and sintering in straw combustion and gasification are generally known. The ash and alkali metal contents of the European biomasses harvested in Italy resembled those of the Nordic straws, and it is expected that they behave to a great extent as straw in gasification. Any direct relation between the ash fusion behavior (determined according to the standard method) and, for instance, the alkali metal content was not found in the laboratory determinations. A more profound characterisation of the fuels would require gasification experiments in a thermobalance and a PDU (Process development Unit) rig. (orig.) (10 refs.)

  1. Possible future HERA analyses

    Energy Technology Data Exchange (ETDEWEB)

    Geiser, Achim

    2015-12-15

    A variety of possible future analyses of HERA data in the context of the HERA data preservation programme is collected, motivated, and commented. The focus is placed on possible future analyses of the existing ep collider data and their physics scope. Comparisons to the original scope of the HERA pro- gramme are made, and cross references to topics also covered by other participants of the workshop are given. This includes topics on QCD, proton structure, diffraction, jets, hadronic final states, heavy flavours, electroweak physics, and the application of related theory and phenomenology topics like NNLO QCD calculations, low-x related models, nonperturbative QCD aspects, and electroweak radiative corrections. Synergies with other collider programmes are also addressed. In summary, the range of physics topics which can still be uniquely covered using the existing data is very broad and of considerable physics interest, often matching the interest of results from colliders currently in operation. Due to well-established data and MC sets, calibrations, and analysis procedures the manpower and expertise needed for a particular analysis is often very much smaller than that needed for an ongoing experiment. Since centrally funded manpower to carry out such analyses is not available any longer, this contribution not only targets experienced self-funded experimentalists, but also theorists and master-level students who might wish to carry out such an analysis.

  2. The pace of shifting climate in marine and terrestrial ecosystems

    DEFF Research Database (Denmark)

    Burrows, Michael T.; Schoeman, David S.; Buckley, Lauren B.;

    2011-01-01

    Climate change challenges organisms to adapt or move to track changes in environments in space and time. We used two measures of thermal shifts from analyses of global temperatures over the past 50 years to describe the pace of climate change that species should track: the velocity of climate cha...

  3. Constructions of Climate Change on the Radio and in Nepalese Lay Focus Groups

    OpenAIRE

    Shrestha, S.; Burningham, KA; Grant, CB

    2014-01-01

    To date analyses of media climate change constructions have mostly focused on coverage in western newspapers. Consideration of coverage in developing countries, and analyses of media constructions alongside local understandings of climate change are comparatively rare. This article provides an analysis of the construction of climate change on Nepalese radio and lay constructions of environment and climate change within the country. Data from a radio programme and six focus groups are analysed...

  4. Uncertainty in climate science and climate policy

    OpenAIRE

    Rougier, Jonathan; Crucifix, Michel

    2014-01-01

    This essay, written by a statistician and a climate scientist, describes our view of the gap that exists between current practice in mainstream climate science, and the practical needs of policymakers charged with exploring possible interventions in the context of climate change. By `mainstream' we mean the type of climate science that dominates in universities and research centres, which we will term `academic' climate science, in contrast to `policy' climate science; aspects of this distinc...

  5. Coexistence, Classroom Climate and Philosophy for Children

    Directory of Open Access Journals (Sweden)

    Gonzalo Romero Izarra

    2008-12-01

    Full Text Available In this paper we analyse the relationship between the classroom’s social climate and the general climate of society in which the school is inserted. We consider essential to start from this reflection in order to define an educational process for social transformation. Philosophy for Children is a methodological option to improve this social climate as it offers teachers and pupils a potentially transforming work that deepens into the values of human relationships for people who are concerned with what happens around them. These are the foundations for democratic relations and a positive classroom social climate.

  6. Climate Change: Basic Information

    Science.gov (United States)

    ... are here: EPA Home Climate Change Basic Information Climate Change: Basic Information On This Page Climate change ... We can make a difference How is the climate changing in the U.S.? Observations across the United ...

  7. Climate and development

    Energy Technology Data Exchange (ETDEWEB)

    Biswas, A.K.

    1984-01-01

    The authors review the existing knowledge on the inter-relationships between climate and patterns of development; the impact variables on water and agricultural development; and the effects of climate on human health. A case study is also given of the effect of climatic fluctuations on human population in Mesopotamia. Contents: Climate and Development; Climate and Agriculture; Climate and Water Management; Climate and Health; Effects of Climate Fluctation on Human Populations; Study of Mesopotamian Society.

  8. Numerical methods using Matlab

    CERN Document Server

    Gupta, Abhishek

    2015-01-01

    Numerical Methods with MATLAB provides a highly-practical reference work to assist anyone working with numerical methods. A wide range of techniques are introduced, their merits discussed and fully working MATLAB code samples supplied to demonstrate how they can be coded and applied. Numerical methods have wide applicability across many scientific, mathematical, and engineering disciplines and are most often employed in situations where working out an exact answer to the problem by another method is impractical. Numerical Methods with MATLAB presents each topic in a concise and readable

  9. Numerical methods using Matlab

    CERN Document Server

    Lindfield, George

    2012-01-01

    Numerical Methods using MATLAB, 3e, is an extensive reference offering hundreds of useful and important numerical algorithms that can be implemented into MATLAB for a graphical interpretation to help researchers analyze a particular outcome. Many worked examples are given together with exercises and solutions to illustrate how numerical methods can be used to study problems that have applications in the biosciences, chaos, optimization, engineering and science across the board. Numerical Methods using MATLAB, 3e, is an extensive reference offering hundreds of use

  10. Digital differential analysers

    CERN Document Server

    Shilejko, A V; Higinbotham, W

    1964-01-01

    Digital Differential Analysers presents the principles, operations, design, and applications of digital differential analyzers, a machine with the ability to present initial quantities and the possibility of dividing them into separate functional units performing a number of basic mathematical operations. The book discusses the theoretical principles underlying the operation of digital differential analyzers, such as the use of the delta-modulation method and function-generator units. Digital integration methods and the classes of digital differential analyzer designs are also reviewed. The te

  11. Analysing Access Control Specifications

    DEFF Research Database (Denmark)

    Probst, Christian W.; Hansen, René Rydhof

    2009-01-01

    common tool to answer this question, analysis of log files, faces the problem that the amount of logged data may be overwhelming. This problems gets even worse in the case of insider attacks, where the attacker’s actions usually will be logged as permissible, standard actions—if they are logged at all....... Recent events have revealed intimate knowledge of surveillance and control systems on the side of the attacker, making it often impossible to deduce the identity of an inside attacker from logged data. In this work we present an approach that analyses the access control configuration to identify the set...

  12. Systemdynamisk analyse av vannkraftsystem

    OpenAIRE

    Rydning, Anja

    2007-01-01

    I denne oppgaven er det gjennomført en dynamisk analyse av vannkraftverket Fortun kraftverk. Tre fenomener er særlig vurdert i denne oppgaven: Sjaktsvingninger mellom svingesjakt og magasin, trykkstøt ved turbinen som følge av retardasjonstrykk ved endring i turbinvannføringen og reguleringsstabilitet. Sjaktsvingningene og trykkstøt beregnes analytisk ut fra kontinuitets- og bevegelsesligningen. Modeller av Fortun kraftverk er laget for å beregne trykkstøt og sjaktsvingninger. En modell e...

  13. Efficient climate policies under technology and climate uncertainty

    International Nuclear Information System (INIS)

    This article explores efficient climate policies in terms of investment streams into fossil and renewable energy technologies. The investment decisions maximise social welfare while observing a probabilistic guardrail for global mean temperature rise under uncertain technology and climate parameters. Such a guardrail constitutes a chance constraint, and the resulting optimisation problem is an instance of chance constrained programming, not stochastic programming as often employed. Our analysis of a model of economic growth and endogenous technological change, MIND, suggests that stringent mitigation strategies cannot guarantee a very high probability of limiting warming to 2 oC since preindustrial time under current uncertainty about climate sensitivity and climate response time scale. Achieving the 2 oC temperature target with a probability P* of 75% requires drastic carbon dioxide emission cuts. This holds true even though we have assumed an aggressive mitigation policy on other greenhouse gases from, e.g., the agricultural sector. The emission cuts are deeper than estimated from a deterministic calculation with climate sensitivity fixed at the P* quantile of its marginal probability distribution (3.6 oC). We show that earlier and cumulatively larger investments into the renewable sector are triggered by including uncertainty in the technology and climate response time scale parameters. This comes at an additional GWP loss of 0.3%, resulting in a total loss of 0.8% GWP for observing the chance constraint. We obtained those results with a new numerical scheme to implement constrained welfare optimisation under uncertainty as a chance constrained programming problem in standard optimisation software such as GAMS. The scheme is able to incorporate multivariate non-factorial probability measures such as given by the joint distribution of climate sensitivity and response time. We demonstrate the scheme for the case of a four-dimensional parameter space capturing

  14. Uncertainty in climate science and climate policy

    CERN Document Server

    Rougier, Jonathan

    2014-01-01

    This essay, written by a statistician and a climate scientist, describes our view of the gap that exists between current practice in mainstream climate science, and the practical needs of policymakers charged with exploring possible interventions in the context of climate change. By `mainstream' we mean the type of climate science that dominates in universities and research centres, which we will term `academic' climate science, in contrast to `policy' climate science; aspects of this distinction will become clearer in what follows. In a nutshell, we do not think that academic climate science equips climate scientists to be as helpful as they might be, when involved in climate policy assessment. Partly, we attribute this to an over-investment in high resolution climate simulators, and partly to a culture that is uncomfortable with the inherently subjective nature of climate uncertainty.

  15. Chapter 5. Safety analyses

    International Nuclear Information System (INIS)

    In 2000 the safety analyses of the Nuclear Regulatory Authority of the Slovak Republic (UJD) were focused on verification of the safety analyses report and probabilistic safety assessment study for NPP V-1 Bohunice after the reconstruction, reviewing of the suggested changes of the Limits and Conditions for NPP V-2 Bohunice and on the assessment of operational events. An important part of work was performed also in solving of scientific and technical tasks appointed within bilateral projects of co-operation between UJD and its international partnerships' organisations, i.e. within international PHARE programme as well as the 5th framework of the European Commission. Verification of safety analyses part of the safety report for NPP V-1 Bohunice after the gradual reconstruction was focused on checking and passing judgement on the completeness of the considered initiating events, safety criteria, input data, adequacy of the used calculation models and also on the overall quality of the submitted documentation. Suitability of the used methodology and the calculation programmes, achieved level of their verification, correctness and interpretation of the results were assessed. The performed review has shown that the checked safety analyses were performed in compliance with the internationally accepted practice, recommendations of UJD and the IAEA. The required level of safety of NPP V-1 Bohunice has been approved. The document with the results and all the findings of the performed review has been prepared. It includes the details of the performed independent calculations, their results and comparison with the results given in the safety report. A special attention was paid to a review of probabilistic safety assessment study of level 1 for NPP Bohunice V-1 after its gradual reconstruction. The probabilistic safety analysis of NPP in full power operation was elaborated in the study and the impact of the gradual reconstruction to the risk decreasing was quantified. The

  16. Uncertainty Analyses and Strategy

    International Nuclear Information System (INIS)

    The DOE identified a variety of uncertainties, arising from different sources, during its assessment of the performance of a potential geologic repository at the Yucca Mountain site. In general, the number and detail of process models developed for the Yucca Mountain site, and the complex coupling among those models, make the direct incorporation of all uncertainties difficult. The DOE has addressed these issues in a number of ways using an approach to uncertainties that is focused on producing a defensible evaluation of the performance of a potential repository. The treatment of uncertainties oriented toward defensible assessments has led to analyses and models with so-called ''conservative'' assumptions and parameter bounds, where conservative implies lower performance than might be demonstrated with a more realistic representation. The varying maturity of the analyses and models, and uneven level of data availability, result in total system level analyses with a mix of realistic and conservative estimates (for both probabilistic representations and single values). That is, some inputs have realistically represented uncertainties, and others are conservatively estimated or bounded. However, this approach is consistent with the ''reasonable assurance'' approach to compliance demonstration, which was called for in the U.S. Nuclear Regulatory Commission's (NRC) proposed 10 CFR Part 63 regulation (64 FR 8640 [DIRS 101680]). A risk analysis that includes conservatism in the inputs will result in conservative risk estimates. Therefore, the approach taken for the Total System Performance Assessment for the Site Recommendation (TSPA-SR) provides a reasonable representation of processes and conservatism for purposes of site recommendation. However, mixing unknown degrees of conservatism in models and parameter representations reduces the transparency of the analysis and makes the development of coherent and consistent probability statements about projected repository

  17. Climate oblige

    International Nuclear Information System (INIS)

    This file contains 15 articles discussing various aspects of the struggle against climatic change: 'greening' the industry in order to cope with the COP 21 expectations of a 2 deg C maximum warming at the end of this century; financing the transition energy policy in the poorest countries; the issues and stakes for the COP 21 conference to be held in Paris; towards an energy system with fossil fuels to be left in the ground, especially coal; emerging and developing countries could be in the future at the forefront to benefit from the renewable energy technologies; towards a 100 pc renewable France with wind and solar power; low carbon electric power (including nuclear power) is one of the best solutions against global warming; solar energy: the example of India and its 100 GW objective in 2022; the main struggle against climatic change lies in the cities and especially with the development of low-energy buildings and energy conservation systems; with de-polluted engine, connectivity and light structure technologies, the automotive sector can mix mobility and environment protection; some examples of the environmental policy underway in Grenoble city; green collective transportation systems in Sweden; application of simulation tools and satellite observations for climatic change forecasting and analysis; the importance of eco-design of manufactured products following the 'from well to wheel' and 'from cradle to grave' concepts

  18. Numerical Methods - III Numerical Methods - III

    OpenAIRE

    Dusan Maga

    2005-01-01

    This contribution deals with giving a possible most simplified view on one of the most frequently used numerical methods – Boundary Element Method (BEM). However, after reading the previous related papers the reader would be able to realize the adequate model by-hand, this time the relative complicate integral formulations probably will not allow to do the same. In spite of this we hope that the principles of this method will also be presented clearly and could be understand.This contribution...

  19. Assessment of Human Health Vulnerability to Climate Variability and Change in Cuba

    OpenAIRE

    Bultó, Paulo Lázaro Ortíz; Rodríguez, Antonio Pérez; Valencia, Alina Rivero; Vega, Nicolás León; Gonzalez, Manuel Díaz; Carrera, Alina Pérez

    2006-01-01

    In this study we assessed the potential effects of climate variability and change on population health in Cuba. We describe the climate of Cuba as well as the patterns of climate-sensitive diseases of primary concern, particularly dengue fever. Analyses of the associations between climatic anomalies and disease patterns highlight current vulnerability to climate variability. We describe current adaptations, including the application of climate predictions to prevent disease outbreaks. Finally...

  20. Hurricane Katrina and climate change

    International Nuclear Information System (INIS)

    Serious and widely reported scientific analyses and assessments have called attention to climate changes and to the additional risks the world now faces. Through science has not yet provided proof positive of a connection between the increased intensity of extreme weather events and climate change, there can be no valid reason for failing to hedge the risk with preventive action. The catastrophe that struck New Orleans had can been predicted since the 1990s. The 2050 Coast Plan for reducing the vulnerability of the Louisiana coast and preventing hurricane disasters had been approved by the local authorities but not the federal government. Partly because of its cost, it was never carried into effect

  1. Numerical Modelling of Streams

    DEFF Research Database (Denmark)

    Vestergaard, Kristian

    In recent years there has been a sharp increase in the use of numerical water quality models. Numeric water quality modeling can be divided into three steps: Hydrodynamic modeling for the determination of stream flow and water levels. Modelling of transport and dispersion of a conservative...

  2. Smallholder Farmers' Adaptation to Climate Change in Zenzelima, Ethiopia

    OpenAIRE

    Skambraks, Anne

    2014-01-01

    Zenzelima is a small kebele located in the North-western part of Ethiopia, where future climate change is predicted to challenge the farmers’ agricultural systems beyond their coping range. Farmers in Zenzelima will therefore need to adapt to climate change in order to maintain their livelihoods in the future. Adaptation to climate change requires the recognition of the need to adapt and the ability to adapt. This study therefore analyses the farmers’ perception of climate change and their...

  3. Evidence of climatic niche shift during biological invasion

    OpenAIRE

    Broennimann, Olivier; Urs A Treier; Müller-Schärer, Heinz; Thuiller, W.; Peterson, A. T.; Guisan, Antoine

    2007-01-01

    Niche-based models calibrated in the native range by relating species observations to climatic variables are commonly used to predict the potential spatial extent of species’ invasion. This climate matching approach relies on the assumption that invasive species conserve their climatic niche in the invaded ranges. We test this assumption by analysing the climatic niche spaces of Spotted Knapweed in western North America and Europe. We show with robust cross-continental data that a shift of th...

  4. Interactions of Mean Climate Change and Climate Variability on Food Security Extremes

    Science.gov (United States)

    Ruane, Alexander C.; McDermid, Sonali; Mavromatis, Theodoros; Hudson, Nicholas; Morales, Monica; Simmons, John; Prabodha, Agalawatte; Ahmad, Ashfaq; Ahmad, Shakeel; Ahuja, Laj R.

    2015-01-01

    Recognizing that climate change will affect agricultural systems both through mean changes and through shifts in climate variability and associated extreme events, we present preliminary analyses of climate impacts from a network of 1137 crop modeling sites contributed to the AgMIP Coordinated Climate-Crop Modeling Project (C3MP). At each site sensitivity tests were run according to a common protocol, which enables the fitting of crop model emulators across a range of carbon dioxide, temperature, and water (CTW) changes. C3MP can elucidate several aspects of these changes and quantify crop responses across a wide diversity of farming systems. Here we test the hypothesis that climate change and variability interact in three main ways. First, mean climate changes can affect yields across an entire time period. Second, extreme events (when they do occur) may be more sensitive to climate changes than a year with normal climate. Third, mean climate changes can alter the likelihood of climate extremes, leading to more frequent seasons with anomalies outside of the expected conditions for which management was designed. In this way, shifts in climate variability can result in an increase or reduction of mean yield, as extreme climate events tend to have lower yield than years with normal climate.C3MP maize simulations across 126 farms reveal a clear indication and quantification (as response functions) of mean climate impacts on mean yield and clearly show that mean climate changes will directly affect the variability of yield. Yield reductions from increased climate variability are not as clear as crop models tend to be less sensitive to dangers on the cool and wet extremes of climate variability, likely underestimating losses from water-logging, floods, and frosts.

  5. Class Generation for Numerical Wind Atlases

    DEFF Research Database (Denmark)

    Cutler, N.J.; Jørgensen, B.H.; Ersbøll, Bjarne Kjær; Badger, J.

    2006-01-01

    A new optimised clustering method is presented for generating wind classes for mesoscale modelling to produce numerical wind atlases. It is compared with the existing method of dividing the data in 12 to 16 sectors, 3 to 7 wind-speed bins and dividing again according to the stability of the...... atmosphere. Wind atlases are typically produced using many years of on-site wind observations at many locations. Numerical wind atlases are the result of mesoscale model integrations based on synoptic scale wind climates and can be produced in a number of hours of computation. 40 years of twice daily NCEP...... optimising the representation of the data and by automating the procedure more. The Karlsruhe Atmospheric Mesoscale Model (KAMM) is combined with the WAsP analysis to produce numerical wind atlases for two sites, Ireland and Egypt. The model results are compared with wind atlases made from measurements at...

  6. Numerical earthquake prediction

    International Nuclear Information System (INIS)

    Can earthquakes be predicted? How should people overcome the difficulties encountered in the study of earthquake prediction? This issue can take inspiration from the experiences of weather forecast. Although weather forecasting took a period of about half a century to advance from empirical to numerical forecast, it has achieved significant success. A consensus has been reached among the Chinese seismological community that earthquake prediction must also develop from empirical forecasting to physical prediction. However, it is seldom mentioned that physical prediction is characterized by quantitatively numerical predictions based on physical laws. This article discusses five key components for numerical earthquake prediction and their current status. We conclude that numerical earthquake prediction should now be put on the planning agenda and its roadmap designed, seismic stations should be deployed and observations made according to the needs of numerical prediction, and theoretical research should be carried out. (authors)

  7. Numerical Verification of Industrial Numerical Codes

    Directory of Open Access Journals (Sweden)

    Montan Sethy

    2012-04-01

    Full Text Available Several approximations occur during a numerical simulation: physical effects mapy be discarded, continuous functions replaced by discretized ones and real numbers replaced by finite-precision representations. The use of the floating point arithmetic generates round-off errors at each arithmetical expression and some mathematical properties are lost. The aim of the numerical verification activity at EDF R&D is to study the effect of the round-off error propagation on the results of a numerical simulation. It is indeed crucial to perform a numerical verification of industrial codes such as developped at EDF R&D even more for code running in HPC environments. This paper presents some recent studies around the numerical verification at EDF R&D. Le résultat d’un code de simulation numérique subit plusieurs approximations effectuées lors de la modélisation mathématique du problème physique, de la discrétisation du modèle mathématique et de la résolution numérique en arithmétique flottante. L’utilisation de l’arithmétique flottante génère en effet des erreurs d’arrondi lors de chaque opération flottante et des propriétés mathématiques sont perdues. Il existe à EDF R&D une activité transverse de vérification numérique consistant à étudier l’effet de la propagation des erreurs d’arrondi sur les résultats des simulations. Il est en effet important de vérifier numériquement des codes industriels et ce d’autant plus s’ils sont éxécutés dans environnements de calcul haute performance. Ce papier présente des études récentes autour de la vérification numérique à EDF R&D.

  8. Climate change, insurance and the building sector: technological synergisms between adaptation and mitigation

    International Nuclear Information System (INIS)

    Examining the intersection of risk analysis and sustainable energy strategies reveals numerous examples of energy-efficient and renewable energy technologies that offer insurance loss-prevention benefits. The growing threat of climate change provides an added motivation for the risk community to understand better this area of opportunity. While analyses of climate change mitigation typically focus on the emissions-reduction characteristics of sustainable energy technologies, less often recognised are a host of synergistic ways in which these technologies also offer adaptation benefits, e.g. making buildings more resilient to natural disasters. While there is already some relevant activity, there remain various barriers to expanding these efforts significantly. Achieving successful integration of sustainable energy considerations with risk-management objectives requires a more proactive orientation, and coordination among diverse actors and industry groups. (author)

  9. Climate change, insurance, and the buildings sector: Technological synergisms between adaptation and mitigation

    Energy Technology Data Exchange (ETDEWEB)

    Mills, Evan

    2002-11-01

    Examining the intersection of risk analysis and sustainable energy strategies reveals numerous examples of energy efficient and renewable energy technologies that offer insurance loss-prevention benefits. The growing threat of climate change provides an added motivation for the risk community to better understand this area of opportunity. While analyses of climate change mitigation typically focus on the emissions-reduction characteristics of sustainable energy technologies, less often recognized are a host of synergistic ways in which these technologies also offer adaptation benefits, e.g. making buildings more resilient to natural disasters. While there is already some relevant activity, there remain various barriers to significantly expanding these efforts. Achieving successful integration of sustainable energy considerations with risk-management objectives requires a more proactive orientation, and coordination among diverse actors and industry groups.

  10. APROS nuclear plant analyser

    International Nuclear Information System (INIS)

    The paper describes the build-up of the Loviisa plant primary circuit model using graphical user interface and generic components. The secondary circuit model of Loviisa is constructed in the same manner. The entire power plant model thus obtained is used for the calculation of two example transients. These examples originate from the Loviisa 2 unit dynamical tests in 1980. The Modular Plant Analyser results are compared with the Loviisa Unit 2 measurement data. This comparison indicates good agreement with the data. The present work has been performed using the Alliant FX/40 minisupercomputer. With this computer the Loviisa model fulfills at present the real-time requirement with 0.5 second timestep. (orig./DG)

  11. EEG analyses with SOBI.

    Energy Technology Data Exchange (ETDEWEB)

    Glickman, Matthew R.; Tang, Akaysha (University of New Mexico, Albuquerque, NM)

    2009-02-01

    The motivating vision behind Sandia's MENTOR/PAL LDRD project has been that of systems which use real-time psychophysiological data to support and enhance human performance, both individually and of groups. Relevant and significant psychophysiological data being a necessary prerequisite to such systems, this LDRD has focused on identifying and refining such signals. The project has focused in particular on EEG (electroencephalogram) data as a promising candidate signal because it (potentially) provides a broad window on brain activity with relatively low cost and logistical constraints. We report here on two analyses performed on EEG data collected in this project using the SOBI (Second Order Blind Identification) algorithm to identify two independent sources of brain activity: one in the frontal lobe and one in the occipital. The first study looks at directional influences between the two components, while the second study looks at inferring gender based upon the frontal component.

  12. Climate Change

    DEFF Research Database (Denmark)

    Richardson, Katherine; Steffen, Will; Liverman, Diana;

    Ministerial careers can be notoriously nasty, brutish, and short, with the doctrine of ministerial accountability leading to numerous prematurely ended political careers. But how do European democracies compare? Looking at evidence from seven countries, Jonathan Bright, Holger Doring, and Conor L...

  13. Mathematical and Physical Ideas for Climate Science

    CERN Document Server

    Lucarini, Valerio; Herbert, Corentin; Pascale, Salvatore; Wouters, Jeroen

    2013-01-01

    The climate is an excellent example of a forced, dissipative system dominated by nonlinear processes and featuring non-trivial dynamics of a vast range of spatial and temporal scales. The understanding of the climate's structural and multiscale properties is crucial for the provision of a unifying picture of its dynamics an thd for the implementation of accurate and efficient numerical models. In this interdisciplinary review, we are guided by our interest in exploring the nexus between climate and concepts such as energy, entropy, symmetry, response, multiscale interactions, and its potential relevance in terms of numerical modeling. We describe the Nambu reformulation of fluid dynamics, and the possible potential of such theory for constructing numerical models of the geophysical fluids. We focus on the very promising results on the statistical mechanics of quasi-equilibrium geophysical flows, which are extremely useful in the direction of constructing a robust theory of geophysical macro turbulence. The se...

  14. Determinants of palm species distributions across Africa: the relative roles of climate, non-climatic environmental factors, and spatial constraints

    DEFF Research Database (Denmark)

    Overgaard, Anne Blach; Svenning, J.-C.; Dransfield, John;

    2010-01-01

    -climatic environmental predictors, the latter having no discernible effect beyond the climatic control. Hence, at the continental scale, climate constitutes the only strong environmental control of palm species distributions in Africa. With regard to the most important climatic predictors of African palm distributions......, water-related factors were most important for 25 of the 29 species analysed. The strong response of palm distributions to climate in combination with the importance of non-environmental spatial constraints suggests that African palms will be sensitive to future climate changes, but that their ability to...

  15. Uralic numerals : is the evolution of numeral system reconstructable? : (Reading new Václav Balzhek's book on numerals in Eurasia) / Vladimir Napolskich

    Index Scriptorium Estoniae

    Napolskich, Vladimir

    2003-01-01

    Rmt.: Balzhek, Václav. Numerals. Comparative-etymological analyses of numeral systems and their implications (saharan, nubian, egyptian, berber, kartvelian, ralic, altaic and indo-european languages). Brno, 1999. (Spisy Masarykovy Univerzity v Brné. Filozofická fakulta; 322). Ülevaade uurali keelte arvsõnu käsitlevast osast

  16. Population effects of increased climate variation

    OpenAIRE

    Drake, John M.

    2005-01-01

    Global circulation models predict and numerous observations confirm that anthropogenic climate change has altered high-frequency climate variability. However, it is not yet well understood how changing patterns of environmental variation will affect wildlife population dynamics and other ecological processes. Theory predicts that a population's long-run growth rate is diminished and the chance of population extinction is increased as environmental variation increases. This results from the fa...

  17. Vulnerability of sandy coasts to climate variability

    OpenAIRE

    Idier, Deborah; Castelle, Bruno; Poumadère, Marc.; Balouin, Yann; Bohn Bertoldo, Raquel; Bouchette, Fréderic; Boulahya, Faiza; Brivois, Olivier; Calvete Manrique, Daniel; Capo, Sylvain; Certain, Raphael; Charles, Elodie; Chateauminois, Eric; Delvallée, Etienne; Falqués Serra, Albert

    2013-01-01

    The main objective of the VULSACO (VULnerability of SAndy COasts to climate change and anthropic pressure) project was to investigate present day and potential future vulnerability of sandy coasts at the 2030 horizon, i.e. on a time scale related to climate variability. The method, based on a multidisciplinary approach bringing together geologists, geographers, physicists, social psychologists, engineers and stakeholders, was structured around 4 axes: field data analysis; numerical modelling;...

  18. The Evaluation of Climate Change Risks

    OpenAIRE

    Popescu, Constantin; Maria-Luiza HRESTIC

    2012-01-01

    Nowadays, it is acknowledged that climatic changes represent a serious threat for the environment and, so, this problem has been approached at numerous conferences, conventions and summits. The climate is strongly influenced by the changes in the atmospheric concentrations of certain gases that hold the solar radiations on the Earth’s surface (the greenhouse effect). The water vapors and the carbon dioxide (CO2) present in the atmosphere have always generated a natural greenhouse effect, with...

  19. Climate - Options for broadening climate policy

    OpenAIRE

    Aerts JCJH; Asselt H van; Bakker SJA; Bayangos V; Beers C van; Berk MM; Biermann F; Bouwer LM; van Bree L; Dorland K; Elzen ME den; Gupta J; Heemst J van; Jansen JC; Nabuurs GJ

    2005-01-01

    In this study ways are explored to increase the policy coherence between the climate regime and a selected number of climate relevant policy areas, by adding a non-climate policy track to national and international climate strategies. The report assesses first the potential, synergies and trade-offs of linking the climate regime to relevant other policy areas, including poverty reduction, land-use, security of energy supply, trade and finance and air quality and health. Next the possibilities...

  20. Mediterranean climate modelling: variability and climate change scenarios

    International Nuclear Information System (INIS)

    Air-sea fluxes, open-sea deep convection and cyclo-genesis are studied in the Mediterranean with the development of a regional coupled model (AORCM). It accurately simulates these processes and their climate variabilities are quantified and studied. The regional coupling shows a significant impact on the number of winter intense cyclo-genesis as well as on associated air-sea fluxes and precipitation. A lower inter-annual variability than in non-coupled models is simulated for fluxes and deep convection. The feedbacks driving this variability are understood. The climate change response is then analysed for the 21. century with the non-coupled models: cyclo-genesis decreases, associated precipitation increases in spring and autumn and decreases in summer. Moreover, a warming and salting of the Mediterranean as well as a strong weakening of its thermohaline circulation occur. This study also concludes with the necessity of using AORCMs to assess climate change impacts on the Mediterranean. (author)

  1. National climate strategy. Finland. Government report to Parliament

    International Nuclear Information System (INIS)

    At the session held in Kyoto in 1997, the Parties to the Climate Convention agreed on legally binding targets for reducing greenhouse gas emissions. Under the so- called Kyoto Protocol, the Member States of the European Community and the European Union shall reduce their annual emissions by eight per cent annually during the years 2008-2012 compared to the 1990 level. Within the Community, the targets have been allotted among the Member States so that Finland's annual greenhouse gas emissions may amount on average to no more than the 1990 level during the commitment period 2008-2012. This National Climate Strategy, submitted to Parliament in the form of a Government report, contains the principles, targets and measures that the Government finds necessary in order to meet our national target. The background material for the strategy consists of sector-specific reports made by the various ministries. The ministerial working group has coordinated the preparation of the strategy. For the strategy, the ministries have carried out and commissioned numerous separate analyses and studies, the reports of which have been published in the course of preparing the strategy. Based on these end the sector-specific reports, a background report to the National Climate Programme entitled 'The Need for and Possibilities of Reducing Greenhouse Gas Emissions in Finland' was compiled for the ministerial working group. The report was co-ordinated by the Kyoto contact network composed of civil servants from the various ministries. The report describes in more detail the factors influencing economic growth, energy consumption and production, and other elements affecting the development of greenhouse gases, which were used as underlying assumptions when determining the recommendations for action under the strategy. The economic and other effects of alternative courses of action were also analysed and described in the above-mentioned background study. It has been published in the Internet on

  2. Classifying climate change adaptation frameworks

    Science.gov (United States)

    Armstrong, Jennifer

    2014-05-01

    Complex socio-ecological demographics are factors that must be considered when addressing adaptation to the potential effects of climate change. As such, a suite of deployable climate change adaptation frameworks is necessary. Multiple frameworks that are required to communicate the risks of climate change and facilitate adaptation. Three principal adaptation frameworks have emerged from the literature; Scenario - Led (SL), Vulnerability - Led (VL) and Decision - Centric (DC). This study aims to identify to what extent these adaptation frameworks; either, planned or deployed are used in a neighbourhood vulnerable to climate change. This work presents a criterion that may be used as a tool for identifying the hallmarks of adaptation frameworks and thus enabling categorisation of projects. The study focussed on the coastal zone surrounding the Sizewell nuclear power plant in Suffolk in the UK. An online survey was conducted identifying climate change adaptation projects operating in the study area. This inventory was analysed to identify the hallmarks of each adaptation project; Levels of dependency on climate model information, Metrics/units of analysis utilised, Level of demographic knowledge, Level of stakeholder engagement, Adaptation implementation strategies and Scale of adaptation implementation. The study found that climate change adaptation projects could be categorised, based on the hallmarks identified, in accordance with the published literature. As such, the criterion may be used to establish the matrix of adaptation frameworks present in a given area. A comprehensive summary of the nature of adaptation frameworks in operation in a locality provides a platform for further comparative analysis. Such analysis, enabled by the criterion, may aid the selection of appropriate frameworks enhancing the efficacy of climate change adaptation.

  3. Numerical problems in physics

    CERN Document Server

    Singh, Devraj

    2015-01-01

    Numerical Problems in Physics, Volume 1 is intended to serve the need of the students pursuing graduate and post graduate courses in universities with Physics and Materials Science as subject including those appearing in engineering, medical, and civil services entrance examinations. KEY FEATURES: * 29 chapters on Optics, Wave & Oscillations, Electromagnetic Field Theory, Solid State Physics & Modern Physics * 540 solved numerical problems of various universities and ompetitive examinations * 523 multiple choice questions for quick and clear understanding of subject matter * 567 unsolved numerical problems for grasping concepts of the various topic in Physics * 49 Figures for understanding problems and concept

  4. Numerical distance protection

    CERN Document Server

    Ziegler, Gerhard

    2011-01-01

    Distance protection provides the basis for network protection in transmission systems and meshed distribution systems. This book covers the fundamentals of distance protection and the special features of numerical technology. The emphasis is placed on the application of numerical distance relays in distribution and transmission systems.This book is aimed at students and engineers who wish to familiarise themselves with the subject of power system protection, as well as the experienced user, entering the area of numerical distance protection. Furthermore it serves as a reference guide for s

  5. Climate Change

    Institute of Scientific and Technical Information of China (English)

    2005-01-01

    According to the National Academy of Sciences in American,the Earth's surface temperature has risen by about 1 degree Fahrenheit in the past century, with accelerated warming during the past two decades. There is new and stronger evidence that most of the warming over the last 50 years is attributable to human activities.Human activities have altered the chemical composition of the atmosphere through the buildup of greenhouse gases-primarily carbon dioxide, methane, and nitrous oxide. The heat-trapping property of these gases is undisputed although uncertainties exist about exactly how earth's climate responds to them.

  6. SSCM analyses of biomass resources in Randers, Norddjurs and Syddjurs

    Energy Technology Data Exchange (ETDEWEB)

    2010-07-15

    This project has been commissioned by ENERCOAST whose overall aim is to stimulate increased use and production of biomass, and create a market for bio energy in the North Sea region. The Enercoast project has been financed by the EU Interreg IVB with partners from Denmark, Germany, United Kingdom, Sweden and Norway. The Danish project leader is AgroBusiness Park/ CBMI /Innovation Centre for Bioenergy and Environmental Technology. Central Region Denmark is co-financing 34% of the Danish portion of the project, while the municipalities of Norddjurs, Syddjurs and Randers are contributing to the project with their working hours. The Danish portion of this project focuses on three Danish municipalities, Randers, Norddjurs, and Syddjurs, and the possibilities to reach local energy and climate targets by increasing the use and production of biomass. The project is divided into 6 phases of which this report is part of the second and third phase which focus on analyses of various biomass resources on a local level including carrying out SSCM analyses of these resources. The aim of this report is to assess the sustainability of relevant bio energy supply chains related to the resource accessibility in the three municipalities with main focus on biogas, straw, wood residues and energy crops for combined heat and power production. Sustainable Supply Chain Management (SSCM) is a concept that has many definitions and the methodologies used to approach this are numerous. In this report the SSCM analysis is used to answer the following question: What are the possibilities of increased use of biomass for energy production in the three municipalities, and what consequences are associated with the utilisation of each of the selected resources described through our case studies? For each of the resource case studies an overview of the supply chain is illustrated through a matrix. Each step of the supply chain from the primal material production in on end to heat and electricity

  7. Choice of baseline climate data impacts projected species' responses to climate change.

    Science.gov (United States)

    Baker, David J; Hartley, Andrew J; Butchart, Stuart H M; Willis, Stephen G

    2016-07-01

    Climate data created from historic climate observations are integral to most assessments of potential climate change impacts, and frequently comprise the baseline period used to infer species-climate relationships. They are often also central to downscaling coarse resolution climate simulations from General Circulation Models (GCMs) to project future climate scenarios at ecologically relevant spatial scales. Uncertainty in these baseline data can be large, particularly where weather observations are sparse and climate dynamics are complex (e.g. over mountainous or coastal regions). Yet, importantly, this uncertainty is almost universally overlooked when assessing potential responses of species to climate change. Here, we assessed the importance of historic baseline climate uncertainty for projections of species' responses to future climate change. We built species distribution models (SDMs) for 895 African bird species of conservation concern, using six different climate baselines. We projected these models to two future periods (2040-2069, 2070-2099), using downscaled climate projections, and calculated species turnover and changes in species-specific climate suitability. We found that the choice of baseline climate data constituted an important source of uncertainty in projections of both species turnover and species-specific climate suitability, often comparable with, or more important than, uncertainty arising from the choice of GCM. Importantly, the relative contribution of these factors to projection uncertainty varied spatially. Moreover, when projecting SDMs to sites of biodiversity importance (Important Bird and Biodiversity Areas), these uncertainties altered site-level impacts, which could affect conservation prioritization. Our results highlight that projections of species' responses to climate change are sensitive to uncertainty in the baseline climatology. We recommend that this should be considered routinely in such analyses. PMID:26950769

  8. Global post-Kyoto scenario analyses at PSI

    Energy Technology Data Exchange (ETDEWEB)

    Kypreos, S. [Paul Scherrer Inst. (PSI), Villigen (Switzerland)

    1999-08-01

    Scenario analyses are described here using the Global MARKAL-Macro Trade (GMMT) model to study the economic implications of the Kyoto Protocol to the UN Convention on Climate change. Some conclusions are derived in terms of efficient implementations of the post-Kyoto extensions of the Protocol. (author) 2 figs., 5 refs.

  9. Micromechanical Analyses of Sturzstroms

    Science.gov (United States)

    Imre, Bernd; Laue, Jan; Springman, Sarah M.

    2010-05-01

    have been made observable and reproducible within a physical and a distinct element numerical modelling environment (DEM). As link between field evidence gained from the deposits of natural sturzstroms, the physical model within the ETH Geotechnical Drum Centrifuge (Springman et al., 2001) and the numerical model PFC-3D (Cundall and Strack, 1979; Itasca, 2005), serves a deterministic fractal analytical comminution model (Sammis et al., 1987; Steacy and Sammis, 1991). This approach allowed studying the effects of dynamic fragmentation within sturzstroms at true (macro) scale within the distinct element model, by allowing for a micro-mechanical, distinct particle based, and cyclic description of fragmentation at the same time, without losing significant computational efficiency. Theses experiments indicate rock mass and boundary conditions, which allow an alternating fragmenting and dilating dispersive regime to evolve and to be sustained long enough to replicate the spreading and run out of sturzstroms. The fragmenting spreading model supported here is able to explain the run out of a dry granular flow, beyond the travel distance predicted by a Coulomb frictional sliding model, without resorting to explanations by mechanics that can only be valid for certain, specific of the boundary conditions. The implications derived suggest that a sturzstrom, because of its strong relation to internal fractal fragmentation and other inertial effects, constitutes a landslide category of its own. Its mechanics differ significantly from all other gravity driven mass flows. This proposition does not exclude the possible appearance of frictionites, Toma hills or suspension flows etc., but it considers them as secondary features. The application of a fractal comminution model to describe natural and experimental sturzstrom deposits turned out to be a useful tool for sturzstrom research. Implemented within the DEM, it allows simulating the key features of sturzstrom successfully and

  10. The butterfly and the tornado: chaos theory and climate change

    International Nuclear Information System (INIS)

    In this book, the author addresses two topics: the theory of chaos, and climate change. The first chapters propose a prehistory and history of chaos, from Newton, Laplace and Lorenz and their controversies as far as prehistory of chaos is concerned, and with different works performed during the twentieth century (Hadamard, Birkhoff, van der Pol, and so on, until Lorenz, the MIT meteorologist and the discovery of the Butterfly Effect, and more recent works by Yorke and Feigenbaum about the logistic equation and the transition to chaos) as far as recent history is concerned. The next chapter describes the deterministic chaos by introducing non linear dynamic systems and distinguishing three regimes: steady, periodic or chaotic. The second part addresses climate change, outlines that global warming is a reality, that the main origin is the increase of greenhouse effect, and that CO2 emissions related to human activity are the main origin of this additional greenhouse effect. The author notably recalls the controversy about the analysis of the global average temperature curve, discusses the assessment of average temperatures from a statistical point of view and in relationship with the uneven distribution of survey stations. The last chapter discusses the numerical modelling of time and climate, and the validity of the Butterfly Effect. The author also proposes a brief overview of the IPCC, discusses the emergence of an international climate policy (UN convention, Kyoto protocol), evokes the use of game theory to ensure a convergence of treaties, and analyses the economic situation of several countries (including Spain) since the Kyoto protocol

  11. Processes Understanding of Decadal Climate Variability

    Science.gov (United States)

    Prömmel, Kerstin; Cubasch, Ulrich

    2016-04-01

    The realistic representation of decadal climate variability in the models is essential for the quality of decadal climate predictions. Therefore, the understanding of those processes leading to decadal climate variability needs to be improved. Several of these processes are already included in climate models but their importance has not yet completely been clarified. The simulation of other processes requires sometimes a higher resolution of the model or an extension by additional subsystems. This is addressed within one module of the German research program "MiKlip II - Decadal Climate Predictions" (http://www.fona-miklip.de/en/) with a focus on the following processes. Stratospheric processes and their impact on the troposphere are analysed regarding the climate response to aerosol perturbations caused by volcanic eruptions and the stratospheric decadal variability due to solar forcing, climate change and ozone recovery. To account for the interaction between changing ozone concentrations and climate a computationally efficient ozone chemistry module is developed and implemented in the MiKlip prediction system. The ocean variability and air-sea interaction are analysed with a special focus on the reduction of the North Atlantic cold bias. In addition, the predictability of the oceanic carbon uptake with a special emphasis on the underlying mechanism is investigated. This addresses a combination of physical, biological and chemical processes.

  12. Introduction to numerical analysis

    CERN Document Server

    Hildebrand, F B

    1987-01-01

    Well-known, respected introduction, updated to integrate concepts and procedures associated with computers. Computation, approximation, interpolation, numerical differentiation and integration, smoothing of data, other topics in lucid presentation. Includes 150 additional problems in this edition. Bibliography.

  13. Advances in Numerical Methods

    CERN Document Server

    Mastorakis, Nikos E

    2009-01-01

    Features contributions that are focused on significant aspects of current numerical methods and computational mathematics. This book carries chapters that advanced methods and various variations on known techniques that can solve difficult scientific problems efficiently.

  14. Numerical integration over pyramids

    OpenAIRE

    Chen, Ch.; Křížek, M.; Liu, L

    2013-01-01

    Pyramidal elements are often used to connect tetrahedral and hexahedral elements in the finite element method. In this paper we derive three new higher order numerical cubature formulae for pyramidal elements.

  15. Numerical semigroups and applications

    CERN Document Server

    Assi, Abdallah

    2016-01-01

    This work presents applications of numerical semigroups in Algebraic Geometry, Number Theory, and Coding Theory. Background on numerical semigroups is presented in the first two chapters, which introduce basic notation and fundamental concepts and irreducible numerical semigroups. The focus is in particular on free semigroups, which are irreducible; semigroups associated with planar curves are of this kind. The authors also introduce semigroups associated with irreducible meromorphic series, and show how these are used in order to present the properties of planar curves. Invariants of non-unique factorizations for numerical semigroups are also studied. These invariants are computationally accessible in this setting, and thus this monograph can be used as an introduction to Factorization Theory. Since factorizations and divisibility are strongly connected, the authors show some applications to AG Codes in the final section. The book will be of value for undergraduate students (especially those at a higher leve...

  16. Climate Analytics as a Service

    Science.gov (United States)

    Schnase, John L.; Duffy, Daniel Q.; McInerney, Mark A.; Webster, W. Phillip; Lee, Tsengdar J.

    2014-01-01

    Climate science is a big data domain that is experiencing unprecedented growth. In our efforts to address the big data challenges of climate science, we are moving toward a notion of Climate Analytics-as-a-Service (CAaaS). CAaaS combines high-performance computing and data-proximal analytics with scalable data management, cloud computing virtualization, the notion of adaptive analytics, and a domain-harmonized API to improve the accessibility and usability of large collections of climate data. MERRA Analytic Services (MERRA/AS) provides an example of CAaaS. MERRA/AS enables MapReduce analytics over NASA's Modern-Era Retrospective Analysis for Research and Applications (MERRA) data collection. The MERRA reanalysis integrates observational data with numerical models to produce a global temporally and spatially consistent synthesis of key climate variables. The effectiveness of MERRA/AS has been demonstrated in several applications. In our experience, CAaaS is providing the agility required to meet our customers' increasing and changing data management and data analysis needs.

  17. Numerical computations with GPUs

    CERN Document Server

    Kindratenko, Volodymyr

    2014-01-01

    This book brings together research on numerical methods adapted for Graphics Processing Units (GPUs). It explains recent efforts to adapt classic numerical methods, including solution of linear equations and FFT, for massively parallel GPU architectures. This volume consolidates recent research and adaptations, covering widely used methods that are at the core of many scientific and engineering computations. Each chapter is written by authors working on a specific group of methods; these leading experts provide mathematical background, parallel algorithms and implementation details leading to

  18. Numerical Validation Methods

    OpenAIRE

    Jauregui, Ricardo; Silva, Ferran

    2011-01-01

    In the last years, numerical simulation has seen a great development thanks to costs reduction and speed increases of the computational systems. With these improvements, the mathematical algorithms are able to work properly with more realistic problems. Nowadays, the solution of a problem using numerical simulation is not just finding a result, but also to ensure the quality. However, can we say that the model results are correct regarding the behaviour of the system? In other words, how c...

  19. Exact Numerical Processing

    OpenAIRE

    García Chamizo, Juan Manuel; Mora Pascual, Jerónimo Manuel; Mora Mora, Higinio

    2003-01-01

    A model of an exact arithmetic processing is presented. We describe a representation format that gives us a greater expressive capability and covers a wider numerical set. The rational numbers are represented by means of fractional notation and explicit codification of its periodic part. We also give a brief description of exact arithmetic operations on the proposed format. This model constitutes a good alternative for the symbolic arithmetic, in special when numerical exact values are requir...

  20. On joint numerical radius

    Czech Academy of Sciences Publication Activity Database

    Müller, Vladimír

    2014-01-01

    Roč. 142, č. 4 (2014), s. 1371-1380. ISSN 0002-9939 R&D Projects: GA ČR GA201/09/0473; GA AV ČR IAA100190903 Institutional support: RVO:67985840 Keywords : joint numerical range * numerical radius Subject RIV: BA - General Mathematics Impact factor: 0.681, year: 2014 http://www.ams.org/journals/proc/2014-142-04/S0002-9939-2014-11876-4/ home .html

  1. Status of numerical relativity

    Indian Academy of Sciences (India)

    Masaru Shibata

    2004-10-01

    I describe the current status of numerical relativity from my personal point of view. Here, I focus mainly on explaining the numerical implementations necessary for simulating general relativistic phenomena such as the merger of compact binaries and stellar collapse, emphasizing the well-developed current status of such implementations that enable simulations for several astrophysical phenomena. Some of our latest results for simulation of binary neutron star mergers are briefly presented.

  2. Intertemporal social choice and climate stabilization

    Energy Technology Data Exchange (ETDEWEB)

    Howarth, R.B. [Dartmouth College, Hanover, NH (United States). Environmental Studies Program

    2001-07-01

    This paper examines the implications of alternative approaches to intertemporal social choice in a numerically calibrated model of interactions between global climate change and the world economy. Under cost-benefit analysis, relatively modest steps towards greenhouse gas emissions abatement are justified as economically efficient. Under classical utilitarianism and the precautionary principle, in contrast, aggressive steps towards climate stabilization emerge as socially optimal. The paper reviews the value judgement that support each of these normative approaches, arguing that the precautionary principle is most loosely tied to the goals and objectives of the Framework Convention on Climate Change. (Author)

  3. Solar magnetic fields and terrestrial climate

    CERN Document Server

    Georgieva, Katya; Kirov, Boian

    2014-01-01

    Solar irradiance is considered one of the main natural factors affecting terrestrial climate, and its variations are included in most numerical models estimating the effects of natural versus anthropogenic factors for climate change. Solar wind causing geomagnetic disturbances is another solar activity agent whose role in climate change is not yet fully estimated but is a subject of intense research. For the purposes of climate modeling, it is essential to evaluate both the past and the future variations of solar irradiance and geomagnetic activity which are ultimately due to the variations of solar magnetic fields. Direct measurements of solar magnetic fields are available for a limited period, but can be reconstructed from geomagnetic activity records. Here we present a reconstruction of total solar irradiance based on geomagnetic data, and a forecast of the future irradiance and geomagnetic activity relevant for the expected climate change.

  4. Climate and environmental change in China. 1951-2012

    International Nuclear Information System (INIS)

    Through numerous color figures and tables, this book presents the most up-to-date knowledge on climate and environmental change in China. It documents the evidence and attribution of climate and environmental changes in the past few decades and discusses the impacts of climate change on environments, economy, and society. The book further provides projections of climate change and its impacts in the future. Finally, it offers the climate change mitigation and adaption technologies with strategic options which will be of interest for policy makers, researchers and the general public as well.

  5. Climate and environmental change in China. 1951-2012

    Energy Technology Data Exchange (ETDEWEB)

    Qin, Dahe [Chinese Academy of Sciences, Lanzhou (China). Cold and Arid Regions Environmental and Engineering Research Institute; Academy of Meteorological Sciences, Beijing, BJ (China). State Meteorological Administration; Ding, Yongjian [Chinese Academy of Sciences, Lanzhou (China). Cold and Arid Regions Environmental and Engineering Research Institute; Mu, Mu (ed.) [Chinese Academy of Sciences, Qingdao (China). Inst. of Oceanology

    2016-02-01

    Through numerous color figures and tables, this book presents the most up-to-date knowledge on climate and environmental change in China. It documents the evidence and attribution of climate and environmental changes in the past few decades and discusses the impacts of climate change on environments, economy, and society. The book further provides projections of climate change and its impacts in the future. Finally, it offers the climate change mitigation and adaption technologies with strategic options which will be of interest for policy makers, researchers and the general public as well.

  6. Agriculture and climate change

    International Nuclear Information System (INIS)

    How will increases in levels of CO2 and changes in temperature affect food production? A recently issued report analyzes prospects for US agriculture 1990 to 2030. The report, prepared by a distinguished Task Force, first projects the evolution of agriculture assuming increased levels of CO2 but no climate change. Then it deals with effects of climate change, followed by a discussion of how greenhouse emissions might be diminished by agriculture. Economic and policy matters are also covered. How the climate would respond to more greenhouse gases is uncertain. If temperatures were higher, there would be more evaporation and more precipitation. Where would the rain fall? That is a good question. Weather in a particular locality is not determined by global averages. The Dust Bowl of the 1930s could be repeated at its former site or located in another region such as the present Corn Belt. But depending on the realities at a given place, farmers have demonstrated great flexibility in choosing what they may grow. Their flexibility has been increased by the numerous varieties of seeds of major crops that are now available, each having different characteristics such as drought resistance and temperature tolerance. In past, agriculture has contributed about 5% of US greenhouse gases. Two large components have involved emissions of CO2 from farm machinery and from oxidation of organic matter in soil due to tillage. Use of diesel fuel and more efficient machinery has reduced emissions from that source by 40%. In some areas changed tillage practices are now responsible for returning carbon to the soil. The report identifies an important potential for diminishing net US emissions of CO2 by growth and utilization of biomass. Large areas are already available that could be devoted to energy crops

  7. Targeting climate diversity in conservation planning to build resilience to climate change

    Science.gov (United States)

    Heller, Nicole E.; Kreitler, Jason R.; Ackerly, David; Weiss, Stuart; Recinos, Amanda; Branciforte, Ryan; Flint, Lorraine E.; Flint, Alan L.; Micheli, Elisabeth

    2015-01-01

    consistently show greater climate stability than homogenous areas. The analysis suggests that utilizing high-resolution climate and hydrological data in conservation planning improves the likely resilience of biodiversity to climate change. We used these analyses to suggest new conservation priorities for the San Francisco Bay Area.

  8. From polycrystal to multi-crystal: ''numerical meso-scope'' development for a local analysis in the elasto-viscoplastic field; Du polycristal au multicristal: elaboration d'un mesoscope numerique pour une analyse locale en elastoviscoplasticite

    Energy Technology Data Exchange (ETDEWEB)

    Heraud, St

    2000-07-01

    The knowledge of the local mechanical fields over several adjacent grains is needed for a better understanding of damage initiation and intergranular. failure in metallic polycrystals. This thesis aimed at the derivation of such fields through a 'numerical meso-scope': this simulation tool relies on the finite element analysis of a multi-crystalline pattern embedded in a large matrix whose mechanical behaviour is derived experimentally from classical tests performed on the studied metal. First, we derived macroscopic elastic-viscoplastic constitutive equations from tensile and creep tests on a AIS1316 stainless steel and we inferred from them the general form of similar, but crystallographic equations to be used for the single crystals; the corresponding parameters were determined by fitting the computed overall response of an aggregate made of 1000 grains with the macroscopic experimental one. We then investigated a creep-damaged area of the same steel and we simulated the same grain ensemble in the 'numerical meso-scope' so as to compare the computed normal stress on all grain boundaries with the observed de-bonded boundaries: this showed the most damaged boundaries to sustain the largest normal stress. Another application was concerned with the understanding of the origin of intergranular damage of aged AIS321 stainless steel. A similar approach was adopted with help of the meso-scope: it showed that observations could not be explained by a sole intragranular hardening as it is currently proposed in the literature. Thus the pertinence of the 'numerical meso-scope' concept can now be demonstrated, which opens on a number of new interesting perspectives. (author)

  9. Climate change

    International Nuclear Information System (INIS)

    The indicators in this bulletin are part of a national set of environmental indicators designed to provide a profile of the state of Canada's environment and measure progress towards sustainable development. A review of potential impacts on Canada shows that such changes would have wide-ranging implications for its economic sectors, social well-being including human health, and ecological systems. This document looks at the natural state of greenhouse gases which help regulate the Earth's climate. Then it looks at human influence and what is being done about it. The document then examines some indicators: Carbon dioxide emissions from fossil fuel use; global atmospheric concentrations of greenhouse gases; and global and Canadian temperature variations

  10. Numerical modeling of foam flows

    International Nuclear Information System (INIS)

    Liquid foam flows are involved in numerous applications, e.g. food and cosmetics industries, oil extraction, nuclear decontamination. Moreover, their study leads to fundamental knowledge: as it is easier to manipulate and analyse, foam is used as a model material to understand the flow of emulsions, polymers, pastes, or cell aggregates, all of which display both solid and liquid behaviour. Systematic experiments performed by Francois Graner et al. provide precise data that emphasize the non Newtonian properties of the foam. Meanwhile, Pierre Saramito proposed a visco-elasto-plastic continuous tensorial model, akin to predict the behaviour of the foam. The goal of this thesis is to understand this complex behaviour, using these two elements. We have built and validated a resolution algorithm based on a bidimensional finite elements methods. The numerical solutions are in excellent agreement with the spatial distribution of all measured quantities, and confirm the predictive capabilities of the model. The dominant parameters have been identified and we evidenced the fact that the viscous, elastic, and plastic contributions to the flow have to be treated simultaneously in a tensorial formalism. We provide a substantial contribution to the understanding of foams and open the path to realistic simulations of complex VEP flows for industrial applications. (author)

  11. Numerical models of groundwater flow and transport

    International Nuclear Information System (INIS)

    This chapter reviews the state-of-the-art in deterministic modeling of groundwater flow and transport processes, which can be used for interpretation of isotope data through groundwater flow analyses. Numerical models which are available for this purpose are described and their applications to complex field problems are discussed. The theoretical bases of deterministic modeling are summarized, and advantages and limitations of numerical models are described. The selection of models for specific applications and their calibration procedures are described, and results of a few illustrative case study type applications are provided. (author). 145 refs, 17 figs, 2 tabs

  12. Tree-rings and climate: Implications for Great Basin paleoenvironmental studies

    International Nuclear Information System (INIS)

    The Quaternary Sciences Center of the Desert Research Institute is currently conducting a multi-phased study of floral, faunal, and geomorphic response to long- and short-term climate change and extremes in assessing Yucca Mountain's suitability as a high-level nuclear waste repository. Preliminary results of these studies indicate synchronous responses in late Holocene tree-ring, palynology and geomorphic records. A tree-ring chronology for paleoclimatic reconstruction is developed by collection of multiple cores from 20-60 living trees and a similar number of dead trees in a climate-sensitive location. Samples are cross-dated and every growth layer in each specimen is measured to the nearest .001 mm. The measured ring width series potentially contain a variety of climatic, biological, and anthropogenic signals. Each ring width series is subjected to a numerical standarization procedure that removes an age-related biological growth trend, reduces endogeneous and exogenous stand disturbance factors, and maximizes any climatic signal that is present. Each of these empirically defined components can be graphically portrayed and subjected to further analyses. The geophysical signal analysis techniques involved in the standarized protocol are well-documented and established. The final result is a tree-ring chronology that represents regional paleoclimatic variability over the time represented by the sample population

  13. Effects of climate change on water demand and water availability for power plants - examples for the German capital Berlin

    Science.gov (United States)

    Voegele, Stefan; Koch, Hagen; Grünewald, Uwe

    2010-05-01

    Effects of climate change on water demand and water availability for power plants - examples for the German capital Berlin Stefan Vögelea, Hagen Kochb&c, Uwe Grünewaldb a Forschungszentrum Jülich, Institute of Energy Research - Systems Analysis and Technology Evaluation, D-52425 Jülich, Germany b Brandenburg University of Technology Cottbus, Chair Hydrology and Water Resources Management, P.O. Box. 101 344, D-03013 Cottbus, Germany c Potsdam Institute for Climate Impact Research, Research Domain Climate Impacts and Vulnerabilities, P.O. Box 601203, D-14412 Potsdam, Germany Numerous power plants in Europe had to be throttled in the summer months of the years 2003 and 2006 due to water shortages and high water temperatures. Therefore, the effects of climate change on water availability and water temperature, and their effects on electric power generation in power plants have received much attention in the last years. The water demand of a power plant for cooling depends on the temperature of the surface waters from which the cooling water is withdrawn. Furthermore, air temperature and air humidity influence the water demand if a cooling tower is used. Beside climatic parameters, the demand for water depends on economic and technological factors as well as on the electricity demand and the socio-political framework. Since the different systems are connected with certain levels of uncertainty, scenarios of socio-economic development and climate change should be used in analyses of climate change on power plants and to identify adaptation measures. In this presentation the effects of global change, comprising technological, socio-economic and climate change, and adaptation options to water shortages for power plants in the German capital Berlin in the short- and long-term are analysed. The interconnection between power plants, i.e. water demand, and water resources management, i.e. water availability, is described in detail. By changing the cooling system of power

  14. Global analysis theory of climate system and its applications

    Institute of Scientific and Technical Information of China (English)

    2003-01-01

    The idea and main theoretical results of the global analysis theory of climate system are briefly summarized in this paper. A theorem on the global behavior of climate system is given, i.e. there exists a global attractor in the dynamical equations of climate, any state of climate system will be evolved into the global attractor as time increases, indicating the nonlinear adjustment process of climate system to external forcing. The different effects of external forcing, dissipation and nonlinearity on the long-term behavior of solutions are pointed out, and some main applications of the global analysis theory are also introduced. Especially, three applications, the adjustment and evolution processes of climate, the principle of numerical model design and the optimally numerical integration, are discussed.

  15. Generation of Reliable Climate Data Records From Satellite Data: The Calibration and Inter-Calibration Challenge

    Science.gov (United States)

    Schulz, Joerg; Roebeling, Rob; Hewison, Tim; Wagner, Sebastien; Lattanzio, Alessio

    2013-04-01

    Earth observations constitute a critical input for monitoring and advancing understanding of the Earth climate system including its variability and change. From observations taken by satellites or ground-based systems so-called Climate Data Records (CDRs) also known as time series of Essential Climate Variables (ECV) can be created. In particular long records of satellite data have a high potential for being utilised for assimilation into Numerical Weather Prediction (NWP) models to create a physically consistent model-based reanalysis, for the assessment of climate model performance and climate studies directly targeting an improved understanding of the mechanisms of climate change and variability. However, the requirements concerning long-term stability and uncertainty for CDRs are challenging. This is because many long-term satellite observations are provided by operational satellite systems build for the purpose of weather and not climate monitoring. Thus, a high demand for satellite radiance data records with quality analysed and corrected observations as well as a homogenisation over time facilitating the use of multiple satellites carrying similar and different instruments exists. The improvement of the quality of a multi-satellite data record is clearly an international challenge. For instance the creation of a CDR from all past and current geostationary satellite instruments needs a collaboration of space agencies worldwide. The WMO Space Program has initialised two relevant activities leading to improved CDRs. The Global Space-based Inter-Calibration System (GSICS) aims at the development of techniques to ensure comparability of satellite measurements taken at different times and locations by different instruments operated by different satellite agencies, and ties all measurements to SI units. The Sustained Coordinated Processing of Environmental Satellite Data for Climate Monitoring (SCOPE-CM) initiative is a major activity to establish a sustained

  16. Managing Climate Change Refugia for Climate Adaptation.

    Science.gov (United States)

    Morelli, Toni Lyn; Daly, Christopher; Dobrowski, Solomon Z; Dulen, Deanna M; Ebersole, Joseph L; Jackson, Stephen T; Lundquist, Jessica D; Millar, Constance I; Maher, Sean P; Monahan, William B; Nydick, Koren R; Redmond, Kelly T; Sawyer, Sarah C; Stock, Sarah; Beissinger, Steven R

    2016-01-01

    Refugia have long been studied from paleontological and biogeographical perspectives to understand how populations persisted during past periods of unfavorable climate. Recently, researchers have applied the idea to contemporary landscapes to identify climate change refugia, here defined as areas relatively buffered from contemporary climate change over time that enable persistence of valued physical, ecological, and socio-cultural resources. We differentiate historical and contemporary views, and characterize physical and ecological processes that create and maintain climate change refugia. We then delineate how refugia can fit into existing decision support frameworks for climate adaptation and describe seven steps for managing them. Finally, we identify challenges and opportunities for operationalizing the concept of climate change refugia. Managing climate change refugia can be an important option for conservation in the face of ongoing climate change. PMID:27509088

  17. Managing Climate Change Refugia for Climate Adaptation

    Science.gov (United States)

    Daly, Christopher; Dobrowski, Solomon Z.; Dulen, Deanna M.; Ebersole, Joseph L.; Jackson, Stephen T.; Lundquist, Jessica D.; Millar, Constance I.; Maher, Sean P.; Monahan, William B.; Nydick, Koren R.; Redmond, Kelly T.; Sawyer, Sarah C.; Stock, Sarah; Beissinger, Steven R.

    2016-01-01

    Refugia have long been studied from paleontological and biogeographical perspectives to understand how populations persisted during past periods of unfavorable climate. Recently, researchers have applied the idea to contemporary landscapes to identify climate change refugia, here defined as areas relatively buffered from contemporary climate change over time that enable persistence of valued physical, ecological, and socio-cultural resources. We differentiate historical and contemporary views, and characterize physical and ecological processes that create and maintain climate change refugia. We then delineate how refugia can fit into existing decision support frameworks for climate adaptation and describe seven steps for managing them. Finally, we identify challenges and opportunities for operationalizing the concept of climate change refugia. Managing climate change refugia can be an important option for conservation in the face of ongoing climate change. PMID:27509088

  18. The meaning and measurement of implementation climate

    Directory of Open Access Journals (Sweden)

    Bergmire Dawn M

    2011-07-01

    Full Text Available Abstract Background Climate has a long history in organizational studies, but few theoretical models integrate the complex effects of climate during innovation implementation. In 1996, a theoretical model was proposed that organizations could develop a positive climate for implementation by making use of various policies and practices that promote organizational members' means, motives, and opportunities for innovation use. The model proposes that implementation climate--or the extent to which organizational members perceive that innovation use is expected, supported, and rewarded--is positively associated with implementation effectiveness. The implementation climate construct holds significant promise for advancing scientific knowledge about the organizational determinants of innovation implementation. However, the construct has not received sufficient scholarly attention, despite numerous citations in the scientific literature. In this article, we clarify the meaning of implementation climate, discuss several measurement issues, and propose guidelines for empirical study. Discussion Implementation climate differs from constructs such as organizational climate, culture, or context in two important respects: first, it has a strategic focus (implementation, and second, it is innovation-specific. Measuring implementation climate is challenging because the construct operates at the organizational level, but requires the collection of multi-dimensional perceptual data from many expected innovation users within an organization. In order to avoid problems with construct validity, assessments of within-group agreement of implementation climate measures must be carefully considered. Implementation climate implies a high degree of within-group agreement in climate perceptions. However, researchers might find it useful to distinguish implementation climate level (the average of implementation climate perceptions from implementation climate strength (the

  19. Numerical Transducer Modeling

    DEFF Research Database (Denmark)

    Henriquez, Vicente Cutanda

    This thesis describes the development of a numerical model of the propagation of sound waves in fluids with viscous and thermal losses, with application to the simulation of acoustic transducers, in particular condenser microphones for measurement. The theoretical basis is presented, numerical...... tools and implementation techniques are described and performance tests are carried out. The equations that govern the motion of fluids with losses and the corresponding boundary conditions are reduced to a form that is tractable for the Boundary Element Method (BEM) by adopting some hypotheses...... that are allowable in this case: linear variations, absence of flow, harmonic time variation, thermodynamical equilibrium and physical dimensions much larger than the molecular mean free path. A formulation of the BEM is also developed with an improvement designed to cope with the numerical difficulty associated...

  20. Numerical Modeling of Ocean Circulation

    Science.gov (United States)

    Miller, Robert N.

    2007-01-01

    The modelling of ocean circulation is important not only for its own sake, but also in terms of the prediction of weather patterns and the effects of climate change. This book introduces the basic computational techniques necessary for all models of the ocean and atmosphere, and the conditions they must satisfy. It describes the workings of ocean models, the problems that must be solved in their construction, and how to evaluate computational results. Major emphasis is placed on examining ocean models critically, and determining what they do well and what they do poorly. Numerical analysis is introduced as needed, and exercises are included to illustrate major points. Developed from notes for a course taught in physical oceanography at the College of Oceanic and Atmospheric Sciences at Oregon State University, this book is ideal for graduate students of oceanography, geophysics, climatology and atmospheric science, and researchers in oceanography and atmospheric science. Features examples and critical examination of ocean modelling and results Demonstrates the strengths and weaknesses of different approaches Includes exercises to illustrate major points and supplement mathematical and physical details

  1. Climate impact from peat utilisation in Sweden

    International Nuclear Information System (INIS)

    The climate impact from the use of peat for energy production in Sweden has been evaluated in terms of contribution to atmospheric radiative forcing. This was done by attempting to answer the question 'What will be the climate impact if one would use 1 m2 of mire for peat extraction during 20 years?'. Two different methods of after-treatment were studied: afforestation and restoration of wetland. The climate impact from a peatland - wetland energy scenario and a peatland - forestry energy scenario was compared to the climate impact from coal, natural gas and forest residues. Sensitivity analyses were performed to evaluate which parameters that are important to take into consideration in order to minimize the climate impact from peat utilisation

  2. Biomathematical Approach Towards a Linear Climatic Index

    Directory of Open Access Journals (Sweden)

    V. Kumar

    1985-01-01

    Full Text Available The approach is aimed towards integration of major climatic elements for evolving a linear climatic index based on annual averages of three climatic parameters, viz; diurnal range of temperatures, daily mean temperature and precipitation respectively. The index is a measure of aridity of a place, being positive for all arid regions and negative for all humid regions and is effectively applicable to high altitudes. The climatic index, so derived, is termed as 'Linear Aridity Index' and has been compared against Thornthwaite's Moisture Index for 32 meteorological stations in India and neighbourhood (including coastal, non-coastal and high altitude which reveals a close correlation between the two indices. More stations in India and neighbourhood have been analysed in terms of the index value for studying the climatic pattern in India. A nomogram has also been developed for quick evaluation of the index from the given values of the three parameters used.

  3. Can increased organic consumption mitigate climate changes?

    DEFF Research Database (Denmark)

    Heerwagen, Lennart Ravn; Andersen, Laura Mørch; Christensen, Tove;

    2014-01-01

    Purpose – The purpose of this paper is to investigate the evidence for a positive correlation between increased consumption of organic products and potential climate change mitigation via decreased consumption of meat and it is discussed to what extent organic consumption is motivated by climate...... correlation between increasing organic budget shares and decreasing meat budget shares is found. People include food-related behaviour such as the purchase of organic food and reduced meat consumption as ways to mitigate climate change. However, other behavioural modifications such as reduction of car usage...... household data would supplement the analyses. Practical implications – Demand-side policies aiming at climate-friendly consumption could be a central factor in combating climate change. Already, food-related mitigation strategies such as lowered meat consumption are established practices among a group of...

  4. TRACKING CLIMATE MODELS

    Data.gov (United States)

    National Aeronautics and Space Administration — CLAIRE MONTELEONI*, GAVIN SCHMIDT, AND SHAILESH SAROHA* Climate models are complex mathematical models designed by meteorologists, geophysicists, and climate...

  5. Gray wolves as climate change buffers in Yellowstone.

    OpenAIRE

    Wilmers Christopher C; Getz Wayne M

    2005-01-01

    Understanding the mechanisms by which climate and predation patterns by top predators co-vary to affect community structure accrues added importance as humans exert growing influence over both climate and regional predator assemblages. In Yellowstone National Park, winter conditions and reintroduced gray wolves (Canis lupus) together determine the availability of winter carrion on which numerous scavenger species depend for survival and reproduction. As climate changes in Yellowstone, therefo...

  6. The Earth's Equilibrium Climate Sensitivity and Thermal Inertia

    OpenAIRE

    Royce, B.S.H.; Lam, S H

    2013-01-01

    The Earth's equilibrium climate sensitivity has received much attention because of its relevance and importance for global warming policymaking. This paper focuses on the Earth's \\emph{thermal inertia time scale} which has received relatively little attention. The difference between the observed transient climate sensitivity and the equilibrium climate sensitivity is shown to be proportional to the thermal inertia time scale, and the numerical value of the proportionality factor is determined...

  7. Numerical analysis of inflation

    International Nuclear Information System (INIS)

    In this paper the mechanism of a cosmological phase transition is addressed in a new way which avoids weaknesses of previous approaches. The effects of inhomogeneities are included explicitly. A numerical analysis is presented in which for a wide class of models the Universe enters a period of new inflation. The analysis is classical and applies to models in which the scalar field responsible for driving inflation is weakly coupled to other fields. We derive heuristic arguments which determine the boundaries of the region in parameter space for which inflation is realized. The agreement with the numerical results is good. This paper complements a previous analytical analysis

  8. Matlab numerical calculations

    CERN Document Server

    Lopez, Cesar

    2015-01-01

    MATLAB is a high-level language and environment for numerical computation, visualization, and programming. Using MATLAB, you can analyze data, develop algorithms, and create models and applications. The language, tools, and built-in math functions enable you to explore multiple approaches and reach a solution faster than with spreadsheets or traditional programming languages, such as C/C++ or Java. This book is designed for use as a scientific/business calculator so that you can get numerical solutions to problems involving a wide array of mathematics using MATLAB. Just look up the function y

  9. Introduction to Numerical Methods

    Energy Technology Data Exchange (ETDEWEB)

    Schoonover, Joseph A. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2016-06-14

    These are slides for a lecture for the Parallel Computing Summer Research Internship at the National Security Education Center. This gives an introduction to numerical methods. Repetitive algorithms are used to obtain approximate solutions to mathematical problems, using sorting, searching, root finding, optimization, interpolation, extrapolation, least squares regresion, Eigenvalue problems, ordinary differential equations, and partial differential equations. Many equations are shown. Discretizations allow us to approximate solutions to mathematical models of physical systems using a repetitive algorithm and introduce errors that can lead to numerical instabilities if we are not careful.

  10. A numerical model of coastline deformation for sandy beach at downstream of a jetty

    Institute of Scientific and Technical Information of China (English)

    SUN Linyun; PAN Junning; XING Fu; LIU Jiaju

    2004-01-01

    A reformed numerical model based on the "one-line theory" for beach deformation is presented. In this model, thechange of beach slope during coastline procession is eonsidered. A wave numerical model combined with wave re-fraction, diffraction and reflection is used to simulate wave climate to increase numerical accuracy. The results showthat the numerical model has a good precision based on the adequate field data. The results can be applied to practical engineering.

  11. Quantifying climate risk - the starting point

    International Nuclear Information System (INIS)

    Full text: All natural systems have evolved to their current state as a result inter alia of the climate in which they developed. Similarly, man-made systems (such as agricultural production) have developed to suit the climate experienced over the last 100 or so years. The capacity of different systems to adapt to changes in climate that are outside those that have been experienced previously is largely unknown. This results in considerable uncertainty when predicting climate change impacts. However, it is possible to quantify the relative probabilities of a range of potential impacts of climate change. Quantifying current climate risks is an effective starting point for analysing the probable impacts of future climate change and guiding the selection of appropriate adaptation strategies. For a farming system to be viable within the current climate, its profitability must be sustained and, therefore, possible adaptation strategies need to be tested for continued viability in a changed climate. The methodology outlined in this paper examines historical patterns of key climate variables (rainfall and temperature) across the season and their influence on the productivity of wheat growing in NSW. This analysis is used to identify the time of year that the system is most vulnerable to climate variation, within the constraints of the current climate. Wheat yield is used as a measure of productivity, which is also assumed to be a surrogate for profitability. A time series of wheat yields is sorted into ascending order and categorised into five percentile groupings (i.e. 20th, 40th, 60th and 80th percentiles) for each shire across NSW (-100 years). Five time series of climate data (which are aggregated daily data from the years in each percentile) are analysed to determine the period that provides the greatest climate risk to the production system. Once this period has been determined, this risk is quantified in terms of the degree of separation of the time series

  12. Indicators for tracking European vulnerabilities to the risks of infectious disease transmission due to climate change.

    Science.gov (United States)

    Suk, Jonathan E; Ebi, Kristie L; Vose, David; Wint, Willy; Alexander, Neil; Mintiens, Koen; Semenza, Jan C

    2014-02-01

    A wide range of infectious diseases may change their geographic range, seasonality and incidence due to climate change, but there is limited research exploring health vulnerabilities to climate change. In order to address this gap, pan-European vulnerability indices were developed for 2035 and 2055, based upon the definition vulnerability = impact/adaptive capacity. Future impacts were projected based upon changes in temperature and precipitation patterns, whilst adaptive capacity was developed from the results of a previous pan-European study. The results were plotted via ArcGISTM to EU regional (NUTS2) levels for 2035 and 2055 and ranked according to quintiles. The models demonstrate regional variations with respect to projected climate-related infectious disease challenges that they will face, and with respect to projected vulnerabilities after accounting for regional adaptive capacities. Regions with higher adaptive capacities, such as in Scandinavia and central Europe, will likely be better able to offset any climate change impacts and are thus generally less vulnerable than areas with lower adaptive capacities. The indices developed here provide public health planners with information to guide prioritisation of activities aimed at strengthening regional preparedness for the health impacts of climate change. There are, however, many limitations and uncertainties when modeling health vulnerabilities. To further advance the field, the importance of variables such as coping capacity and governance should be better accounted for, and there is the need to systematically collect and analyse the interlinkages between the numerous and ever-expanding environmental, socioeconomic, demographic and epidemiologic datasets so as to promote the public health capacity to detect, forecast, and prepare for the health threats due to climate change. PMID:24566049

  13. Indicators for Tracking European Vulnerabilities to the Risks of Infectious Disease Transmission due to Climate Change

    Directory of Open Access Journals (Sweden)

    Jonathan E. Suk

    2014-02-01

    Full Text Available A wide range of infectious diseases may change their geographic range, seasonality and incidence due to climate change, but there is limited research exploring health vulnerabilities to climate change. In order to address this gap, pan-European vulnerability indices were developed for 2035 and 2055, based upon the definition vulnerability = impact/adaptive capacity. Future impacts were projected based upon changes in temperature and precipitation patterns, whilst adaptive capacity was developed from the results of a previous pan-European study. The results were plotted via ArcGISTM to EU regional (NUTS2 levels for 2035 and 2055 and ranked according to quintiles. The models demonstrate regional variations with respect to projected climate-related infectious disease challenges that they will face, and with respect to projected vulnerabilities after accounting for regional adaptive capacities. Regions with higher adaptive capacities, such as in Scandinavia and central Europe, will likely be better able to offset any climate change impacts and are thus generally less vulnerable than areas with lower adaptive capacities. The indices developed here provide public health planners with information to guide prioritisation of activities aimed at strengthening regional preparedness for the health impacts of climate change. There are, however, many limitations and uncertainties when modeling health vulnerabilities. To further advance the field, the importance of variables such as coping capacity and governance should be better accounted for, and there is the need to systematically collect and analyse the interlinkages between the numerous and ever-expanding environmental, socioeconomic, demographic and epidemiologic datasets so as to promote the public health capacity to detect, forecast, and prepare for the health threats due to climate change.

  14. Inhomogeneous Forcing and Transient Climate Sensitivity

    Science.gov (United States)

    Shindell, Drew T.

    2014-01-01

    Understanding climate sensitivity is critical to projecting climate change in response to a given forcing scenario. Recent analyses have suggested that transient climate sensitivity is at the low end of the present model range taking into account the reduced warming rates during the past 10-15 years during which forcing has increased markedly. In contrast, comparisons of modelled feedback processes with observations indicate that the most realistic models have higher sensitivities. Here I analyse results from recent climate modelling intercomparison projects to demonstrate that transient climate sensitivity to historical aerosols and ozone is substantially greater than the transient climate sensitivity to CO2. This enhanced sensitivity is primarily caused by more of the forcing being located at Northern Hemisphere middle to high latitudes where it triggers more rapid land responses and stronger feedbacks. I find that accounting for this enhancement largely reconciles the two sets of results, and I conclude that the lowest end of the range of transient climate response to CO2 in present models and assessments (less than 1.3 C) is very unlikely.

  15. Climatic controls on diffuse groundwater recharge across Australia

    Directory of Open Access Journals (Sweden)

    O. V. Barron

    2012-05-01

    Full Text Available Reviews of field studies of groundwater recharge have attempted to investigate how climate characteristics control recharge, but due to a lack of data have not been able to draw any strong conclusions beyond that rainfall is the major determinant. This study has used numerical modeling for a range of Köppen-Geiger climate types (tropical, arid and temperate to investigate the effect of climate variables on recharge for different soil and vegetation types. For the majority of climate types the total annual rainfall had a weaker correlation with recharge than the rainfall parameters reflecting rainfall intensity. In regions with winter-dominated rainfall, annual recharge under the same annual rainfall, soils and vegetation conditions is greater than in regions with summer-dominated rainfall. The relative importance of climate parameters other than rainfall is higher for recharge under annual vegetation, but overall is highest in the tropical climate type. Solar radiation and vapour pressure deficit show a greater relative importance than mean annual daily mean temperature. Climate parameters have lowest relative importance in the arid climate type (with cold winters and the temperate climate type. For 75% of all considered cases of soil, vegetation and climate types recharge elasticity varies between 2 and 4, indicating a 20% to 40% change in recharge for a 10% change in annual rainfall Understanding how climate controls recharge under the observed historical climate allows more informed choices of analogue sites if they are to be used for climate change impact assessments.

  16. Species distributions and climate change - linking the past and the future

    DEFF Research Database (Denmark)

    Levinsky, Irina

    light on the impact of future climate change on biodiversity. In my PhD, I relate past climatic changes and their impact on the distributions of African birds and mammals to potential impacts of future climate change: I revisit the role of refugia as areas where species survived adverse climatic......Climate change is predicted to have a marked impact on biodiversity, and changes in the distributions of numerous species have already been correlated with ongoing climate change. Climatic oscillations, however, were also the rule during the Pleistocene, and a look to the past may therefore shed...

  17. Analysis of numerical methods

    CERN Document Server

    Isaacson, Eugene

    1994-01-01

    This excellent text for advanced undergraduates and graduate students covers norms, numerical solution of linear systems and matrix factoring, iterative solutions of nonlinear equations, eigenvalues and eigenvectors, polynomial approximation, and other topics. It offers a careful analysis and stresses techniques for developing new methods, plus many examples and problems. 1966 edition.

  18. Inhomogeneous inflation: Numerical evolution

    Energy Technology Data Exchange (ETDEWEB)

    Kurki-Suonio, H. (Department of Theoretical Physics, University of Helsinki, 00014 Helsinki (Finland) University of California, Lawrence Livermore National Laboratory, Livermore, California 94550 (United States)); Laguna, P. (Department of Astronomy and Astrophysics, The Pennsylvania State University, University Park, Pennsylvania 16802 (United States)); Matzner, R.A. (Center for Relativity, The University of Texas at Austin, Austin, Texas 78712 (United States))

    1993-10-15

    We describe our three-dimensional numerical relativity code for the evolution of inhomogeneous cosmologies. During the evolution, the constraint equations are monitored but not solved. The code has been tested against perturbation theory with good results. We present some runs of inhomogeneous inflation with strongly inhomogeneous initial data.

  19. Numerical analysis using Sage

    CERN Document Server

    Anastassiou, George A

    2015-01-01

    This is the first numerical analysis text to use Sage for the implementation of algorithms and can be used in a one-semester course for undergraduates in mathematics, math education, computer science/information technology, engineering, and physical sciences. The primary aim of this text is to simplify understanding of the theories and ideas from a numerical analysis/numerical methods course via a modern programming language like Sage. Aside from the presentation of fundamental theoretical notions of numerical analysis throughout the text, each chapter concludes with several exercises that are oriented to real-world application.  Answers may be verified using Sage.  The presented code, written in core components of Sage, are backward compatible, i.e., easily applicable to other software systems such as Mathematica®.  Sage is  open source software and uses Python-like syntax. Previous Python programming experience is not a requirement for the reader, though familiarity with any programming language is a p...

  20. IFS Numerical Laboratory Tokamak

    International Nuclear Information System (INIS)

    A numerical laboratory of a tokamak plasma is being developed. This consists of the backbone (the overall manager in terms of the MPPL programming language), and the modularized components that can be plugged in or out for a particular run and their hierarchical arrangement. The components include various metrics for overall geometry various dynamics, field calculations, and diagnoses. 2 refs

  1. Abrupt climate change and extinction events

    Science.gov (United States)

    Crowley, Thomas J.

    1988-01-01

    There is a growing body of theoretical and empirical support for the concept of instabilities in the climate system, and indications that abrupt climate change may in some cases contribute to abrupt extinctions. Theoretical indications of instabilities can be found in a broad spectrum of climate models (energy balance models, a thermohaline model of deep-water circulation, atmospheric general circulation models, and coupled ocean-atmosphere models). Abrupt transitions can be of several types and affect the environment in different ways. There is increasing evidence for abrupt climate change in the geologic record and involves both interglacial-glacial scale transitions and the longer-term evolution of climate over the last 100 million years. Records from the Cenozoic clearly show that the long-term trend is characterized by numerous abrupt steps where the system appears to be rapidly moving to a new equilibrium state. The long-term trend probably is due to changes associated with plate tectonic processes, but the abrupt steps most likely reflect instabilities in the climate system as the slowly changing boundary conditions caused the climate to reach some threshold critical point. A more detailed analysis of abrupt steps comes from high-resolution studies of glacial-interglacial fluctuations in the Pleistocene. Comparison of climate transitions with the extinction record indicates that many climate and biotic transitions coincide. The Cretaceous-Tertiary extinction is not a candidate for an extinction event due to instabilities in the climate system. It is quite possible that more detailed comparisons and analysis will indicate some flaws in the climate instability-extinction hypothesis, but at present it appears to be a viable candidate as an alternate mechanism for causing abrupt environmental changes and extinctions.

  2. Planetary climates (princeton primers in climate)

    CERN Document Server

    Ingersoll, Andrew

    2013-01-01

    This concise, sophisticated introduction to planetary climates explains the global physical and chemical processes that determine climate on any planet or major planetary satellite--from Mercury to Neptune and even large moons such as Saturn's Titan. Although the climates of other worlds are extremely diverse, the chemical and physical processes that shape their dynamics are the same. As this book makes clear, the better we can understand how various planetary climates formed and evolved, the better we can understand Earth's climate history and future.

  3. Polar ices: rapid climatic changes

    International Nuclear Information System (INIS)

    The recent successes of the European GRIP (GReenland Ice core Project) and American GISP 2 (Greenland Ice Sheet Project) drillings which have reached in 1992 and 1993 the basement rocks of central Greenland (SUMMIT site, 3250 m of altitude) have allow to reconstruct the climate evolution for the last 100,000 years or more. A comparison of climatic informations deduced from these two drillings with records from Vostok (Antarctica) is given in this paper. The δD and δ18O isotopic approach have been used for the reconstruction of climatic series and paleotemperatures in polar regions. Empirical relationships explained by Rayleigh's isotopic models are used as a base for paleotemperature reconstructions from isotopic analyses of ice. A one degree Celsius cooling corresponds to an oxygen 18 decay of 0.67 per thousand and to a 6 per thousand deuterium decay. The GRIP and GISP 2 drillings have demonstrated the exceptional stability of Greenland climate during the last 10.000 years in comparison with strong instabilities encountered during the last 100.000 years and also recorded in North Atlantic marine sediments. The time scales associated with these instabilities are of the order of a few decades for the warming phase. Thanks to Vostok ice-trapped air bubbles analyses, it is now well demonstrated that the strongest instabilities (cooling during the last deglaciation and major glaciation inter stages) are also recorded but less pronounced in Antarctica. GRIP data for the last interglacial stage have been interpreted in terms of climate instabilities but neither GISP 2 results nor Vostok results allow to confirm this interpretation. (J.S.). 29 refs, 3 figs

  4. Numerical Stochastic Perturbation Theory for full QCD

    OpenAIRE

    F. Di Renzo; Scorzato, L.

    2004-01-01

    We give a full account of the Numerical Stochastic Perturbation Theory method for Lattice Gauge Theories. Particular relevance is given to the inclusion of dynamical fermions, which turns out to be surprisingly cheap in this context. We analyse the underlying stochastic process and discuss the convergence properties. We perform some benchmark calculations and - as a byproduct - we present original results for Wilson loops and the 3-loop critical mass for Wilson fermions.

  5. Advanced numerical techniques in core simulations

    International Nuclear Information System (INIS)

    The whole core simulations are one of the most CPU intensive calculations in reactor physics design and analyses. For a designer it is imperative to perform these calculations with good accuracy and in least time possible to try out various options. It is important for the code developers to use techniques involving minimum approximations and to use most recent numerical methods applied in tandem with huge computing power available today. In the presented paper, some of these methods are discussed. (author)

  6. Insurance Companies’ Responses to Climate Change: Adaptation, Dynamic Capabilities and Competitive Advantage

    OpenAIRE

    Kristin Stechemesser; Jan Endrikat; Nico Grasshoff; Edeltraud Guenther

    2015-01-01

    Drawing on the dynamic capability view, we analyse how insurers adapt to climate change impacts and how adaptation relates to corporate financial performance. Based on a comprehensive literature review, we deduce seven categories of adaptation measures associated with three dynamic capability dimensions of climate change adaptation (i.e. climate knowledge absorption, climate-related operational flexibility and strategic climate integration). Using this framework, we conduct a content analysis...

  7. Database application platform for earthquake numerical simulation

    Institute of Scientific and Technical Information of China (English)

    LUO Yan; ZHENG Yue-jun; CHEN Lian-wang; LU Yuan-zhong; HUANG Zhong-xian

    2006-01-01

    @@ Introduction In recent years, all kinds of observation networks of seismology have been established, which have been continuously producing numerous digital information. In addition, there are many study results about 3D velocity structure model and tectonic model of crust (Huang and Zhao, 2006; Huang et al, 2003; Li and Mooney, 1998),which are valuable for studying the inner structure of the earth and earthquake preparation process. It is badly needed to combine the observed data, experimental study and theoretical analyses results by the way of numerical simulation and develop a database and a corresponding application platform to be used by numerical simulation,and is also a significant way to promote earthquake prediction.

  8. Numerical shadow and geometry of quantum states

    International Nuclear Information System (INIS)

    The totality of normalized density matrices of dimension N forms a convex set QN in RN2-1. Working with the flat geometry induced by the Hilbert-Schmidt distance, we consider images of orthogonal projections of QN onto a two-plane and show that they are similar to the numerical ranges of matrices of dimension N. For a matrix A of dimension N, one defines its numerical shadow as a probability distribution supported on its numerical range W(A), induced by the unitarily invariant Fubini-Study measure on the complex projective manifold CPN-1. We define generalized, mixed-state shadows of A and demonstrate their usefulness to analyse the structure of the set of quantum states and unitary dynamics therein.

  9. Numerical simulation and analysis of axial instabilities occurrence and development in turbomachines. Application to a break transient in a helium nuclear reactor; Simulation numerique et analyse du declenchement et du developpement des instabilites axiales dans les turbomachines: application a un transitoire de breche dans un reacteur nucleaire a helium

    Energy Technology Data Exchange (ETDEWEB)

    Tauveron, N

    2006-02-15

    The subject of the present work was to develop models able to simulate axial instabilities occurrence and development in multistage turbomachines. The construction of a 1D unsteady axisymmetric model of internal flow in a turbomachine (at the scale of the row) has followed different steps: generation of steady correlations, adapted to different regimes (off-design conditions, low mass flowrate, negative mass flow rate); building of a model able to describe transient behaviour; use of implicit time schemes adapted to long transients; validation of the model in comparison of experimental investigations, measurements and numerical results from the bibliography. This model is integrated in a numerical tool, which has the capacity to describe the gas dynamics in a complete circuit containing different elements (ducts, valves, plenums). Thus, the complete model can represent the coupling between local and global phenomena, which is a very important mechanism in axial instability occurrence and development. An elementary theory has also been developed, based on a generalisation of Greitzer's model. These models, which were validated on various configurations, have provided complementary elements for the validation of the complete model. They have also allowed a more comprehensive description of physical phenomena at stake in instability occurrence and development by quantifying various effects (inertia, compressibility, performance levels) and underlying the main phenomena (in particular the collapse and recovery kinetics of the plenum), which were the only retained in the final elementary theory. The models were first applied to academic configurations (compression system), and then to an innovative industrial project: a helium cooled fast nuclear reactor with a Brayton cycle. The use of the models have brought comprehensive elements to surge occurrence due to a break event. It has been shown that surge occurrence is highly dependent of break location and that surge

  10. A numerical study on a lumped-parameter model and a CFD code coupling for the analysis of the loss of coolant accident in a reactor containment; Etude numerique 0D-multiD pour l'analyse de perte de refrigerant dans une enceinte de confinement d'un reacteur nucleaire

    Energy Technology Data Exchange (ETDEWEB)

    Choi, Y.J.

    2005-12-15

    In the case of PWR severe accident (Loss of Coolant Accident, LOCA), the inner containment ambient properties such as temperature, pressure and gas species concentrations due to the released steam condensation are the main factors that determine the risk. For this reason, their distributions should be known accurately, but the complexity of the geometry and the computational costs are strong limitations to conduct full three-dimensional numerical simulations. An alternative approach is presented in this thesis, namely, the coupling between a lumped-parameter model and a CFD. The coupling is based on the introduction of a 'heat transfer function' between both models and it is expected that large decreases in the CPU-costs may be achieved. First of all, wall condensation models, such as the Uchida or the Chilton-Colburn models which are implemented in the code CAST3M/TONUS, are investigated. They are examined through steady-state calculations by using the code TONUS-0D, based on lumped parameter models. The temperature and the pressure within the inner containment are compared with those reported in the archival literature. In order to build the 'heat transfer function', natural convection heat transfer is then studied by using the code CAST3M for a partitioned cavity which represents a simplified geometry of the reactor containment. At a first step, two-dimensional natural convection heat transfer without condensation is investigated only. Either the incompressible-Boussinesq fluid flow model or the asymptotic low Mach model are considered for solving the time dependent conservation equations. The SUPG finite element method and the implicit scheme are applied for the numerical discretization. The computed results are qualified by the second-order Richardson extrapolation method which allows obtaining the so-called 'Exact values', i.e. grid size independent values. The computations are also validated through non-partitioned cavity case

  11. Report of the workshop on Climate Sensitivity

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2004-07-01

    The IPCC Working Group I (WGI) held this Workshop on Climate Sensitivity as a major keystone in activities preparing for the WGI contribution to the IPCC Fourth Assessment Report (AR4). One of the most important parameters in climate science is the 'climate sensitivity', broadly defined as the global mean temperature change for a given forcing, often that of a doubling of atmospheric carbon dioxide. Climate sensitivity has played a central role throughout the history of IPCC in interpretation of model outputs, in evaluation of future climate changes expected from various scenarios, and it is closely linked to attribution of currently observed climate changes. An ongoing challenge to models and to climate projections has been to better define this key parameter, and to understand the differences in computed values between various models. Throughout the last three IPCC assessments the climate sensitivity has been estimated as being in the range 1.5 to 4.5 deg. C for CO{sub 2} doubling (i.e., uncertain by a factor of three), making this parameter central to discussions of uncertainty in climate change. The aims of the workshop were to: - Evaluate a range of climate model results so as to relate different climate sensitivity estimates to differences descriptions of physical processes, particularly those related to atmospheric water vapor, clouds, lapse rate changes, ocean heat uptake, treatment of evapotranspiration, land-atmosphere coupling, etc.; - Obtain a more comprehensive picture of the relationships between climate sensitivity and other model features such as resolution, numerical approach, radiative transfer parameters, etc.; - Consider how current, historical, and paleo-climatic data can aid in the determination of the likely range of climate sensitivity; - Improve the understanding of the interpretation and limits of the climate sensitivity concept, including for example possible dependencies upon different forcing agents, predictability questions

  12. Climate Change Schools Project...

    Science.gov (United States)

    McKinzey, Krista

    2010-01-01

    This article features the award-winning Climate Change Schools Project which aims to: (1) help schools to embed climate change throughout the national curriculum; and (2) showcase schools as "beacons" for climate change teaching, learning, and positive action in their local communities. Operating since 2007, the Climate Change Schools Project…

  13. Climate changes your business

    International Nuclear Information System (INIS)

    Businesses face much bigger climate change costs than they realise. That is the conclusion of Climate Changes Your Business. The climate change risks that companies should be paying more attention to are physical risks, regulatory risks as well as risk to reputation and the emerging risk of litigation, says the report. It argues that the risks associated with climate change tend to be underestimated

  14. Assessing climate impacts

    OpenAIRE

    Wohl, Ellen E.; Roger S. Pulwarty; Zhang, Jian Yun

    2000-01-01

    Assessing climate impacts involves identifying sources and characteristics of climate variability, and mitigating potential negative impacts of that variability. Associated research focuses on climate driving mechanisms, biosphere–hydrosphere responses and mediation, and human responses. Examples of climate impacts come from 1998 flooding in the Yangtze River Basin and hurricanes in the Caribbean and Central America. Although we have limited understanding of the fu...

  15. Climate Change: The Physical Basis and Latest Results

    CERN Document Server

    CERN. Geneva

    2009-01-01

    The 2007 Assessment Report of the Intergovernmental Panel on Climate Change (IPCC) concludes: "Warming in the climate system is unequivocal." Without the contribution of Physics to climate science over many decades, such a statement would not have been possible. Experimental physics enables us to read climate archives such as polar ice cores and so provides the context for the current changes. For example, today the concentration of CO2 in the atmosphere, the second most important greenhouse gas, is 28% higher than any time during the last 800,000 years. Classical fluid mechanics and numerical mathematics are the basis of climate models from which estimates of future climate change are obtained. But major instabilities and surprises in the Earth System are still unknown. These are also to be considered when the climatic consequences of proposals for geo-engineering are estimated. Only Physics will permit us to further improve our understanding in order to provide the foundation for policy decisions facing the...

  16. Climate Networks and Extreme Events

    Science.gov (United States)

    Kurths, J.

    2014-12-01

    We analyse some climate dynamics from a complex network approach. This leads to an inverse problem: Is there a backbone-like structure underlying the climate system? For this we propose a method to reconstruct and analyze a complex network from data generated by a spatio-temporal dynamical system. This approach enables us to uncover relations to global circulation patterns in oceans and atmosphere. The global scale view on climate networks offers promising new perspectives for detecting dynamical structures based on nonlinear physical processes in the climate system. Moreover, we evaluate different regional climate models from this aspect. This concept is also applied to Monsoon data in order to characterize the regional occurrence of extreme rain events and its impact on predictability. Changing climatic conditions have led to a significant increase in magnitude and frequency of spatially extensive extreme rainfall events in the eastern Central Andes of South America. These events impose substantial natural hazards for population, economy, and ecology by floods and landslides. For example, heavy floods in Bolivia in early 2007 affected more than 133.000 households and produced estimated costs of 443 Mio. USD. Here, we develop a general framework to predict extreme events by combining a non-linear synchronization technique with complex networks. We apply our method to real-time satellite-derived rainfall data and are able to predict a large amount of extreme rainfall events. Our study reveals a linkage between polar and subtropical regimes as responsible mechanism: Extreme rainfall in the eastern Central Andes is caused by the interplay of northward migrating frontal systems and a low-level wind channel from the western Amazon to the subtropics, providing additional moisture. Frontal systems from the Antarctic thus play a key role for sub-seasonal variability of the South American Monsoon System.

  17. Climate Services to Improve Public Health

    Directory of Open Access Journals (Sweden)

    Michel Jancloes

    2014-04-01

    Full Text Available A high level expert panel discussed how climate and health services could best collaborate to improve public health. This was on the agenda of the recent Third International Climate Services Conference, held in Montego Bay, Jamaica, 4–6 December 2013. Issues and challenges concerning a demand led approach to serve the health sector needs, were identified and analysed. Important recommendations emerged to ensure that innovative collaboration between climate and health services assist decision-making processes and the management of climate-sensitive health risk. Key recommendations included: a move from risk assessment towards risk management; the engagement of the public health community with both the climate sector and development sectors, whose decisions impact on health, particularly the most vulnerable; to increase operational research on the use of policy-relevant climate information to manage climate- sensitive health risks; and to develop in-country capacities to improve local knowledge (including collection of epidemiological, climate and socio-economic data, along with institutional interaction with policy makers.

  18. Scaling Climate Change Communication for Behavior Change

    Science.gov (United States)

    Rodriguez, V. C.; Lappé, M.; Flora, J. A.; Ardoin, N. M.; Robinson, T. N.

    2014-12-01

    Ultimately, effective climate change communication results in a change in behavior, whether the change is individual, household or collective actions within communities. We describe two efforts to promote climate-friendly behavior via climate communication and behavior change theory. Importantly these efforts are designed to scale climate communication principles focused on behavior change rather than soley emphasizing climate knowledge or attitudes. Both cases are embedded in rigorous evaluations (randomized controlled trial and quasi-experimental) of primary and secondary outcomes as well as supplementary analyses that have implications for program refinement and program scaling. In the first case, the Girl Scouts "Girls Learning Environment and Energy" (GLEE) trial is scaling the program via a Massive Open Online Course (MOOC) for Troop Leaders to teach the effective home electricity and food and transportation energy reduction programs. The second case, the Alliance for Climate Education (ACE) Assembly Program, is advancing the already-scaled assembly program by using communication principles to further engage youth and their families and communities (school and local communities) in individual and collective actions. Scaling of each program uses online learning platforms, social media and "behavior practice" videos, mastery practice exercises, virtual feedback and virtual social engagement to advance climate-friendly behavior change. All of these communication practices aim to simulate and advance in-person train-the-trainers technologies.As part of this presentation we outline scaling principles derived from these two climate change communication and behavior change programs.

  19. Differences in the climatic debts of birds and butterflies at a continental scale

    NARCIS (Netherlands)

    Devictor, V.; Swaay, van C.; Brereton, T.; Brotons, L.; Chamberlain, D.; Heliölä, J.; Herrando, S.; Julliard, R.; Kuussaari, M.; Lindström, A.; Reif, J.; Roy, D.B.; Schweiger, O.; Settele, J.; Stefanescu, C.; Strien, van A.; Turnhout, van C.; Vermouzek, Z.; Wallis de Vries, M.F.; Wynhoff, I.; Jiguet, F.

    2012-01-01

    Climate changes have profound effects on the distribution of numerous plant and animal species(1-3). However, whether and how different taxonomic groups are able to track climate changes at large spatial scales is still unclear. Here, we measure and compare the climatic debt accumulated by bird and

  20. Numerical simulation of welding

    DEFF Research Database (Denmark)

    Hansen, Jan Langkjær; Thorborg, Jesper

    , good predictions of the thermal field are obtained. This has been verified with experiments. The significance of the right fitting of the model to the topical welding process must be emphasized. With a mechanical model in ABAQUS based on a thermal model as described, distributions of both transient...... welding process. Various circumstances are process dependent and require not only knowledge of the process in practice butalso a thorough experience with the numerical modelling of the problem....

  1. a numerical study

    OpenAIRE

    Sousa, Antonio C. M.

    2015-01-01

    This paper reports on a numerical study for steady flow and heat transfer distribution for a configuration relevant to Liquid Composite Molding, where agap between a porous substrate and the solid boundary of a mold cavity yieldsan edge flow. The flowwithin the porous domain is modeled by the Brinkman-Forchheimer formulation, and the edge flow itself is described by theNavier-Stokes equations. The cure of the fluid (resin) is simulated as a volumetric heat generation. The predictions are obta...

  2. Hybrid undulator numerical optimization

    Energy Technology Data Exchange (ETDEWEB)

    Hairetdinov, A.H. [Kurchatov Institute, Moscow (Russian Federation); Zukov, A.A. [Solid State Physics Institute, Chernogolovka (Russian Federation)

    1995-12-31

    3D properties of the hybrid undulator scheme arc studied numerically using PANDIRA code. It is shown that there exist two well defined sets of undulator parameters which provide either maximum on-axis field amplitude or minimal higher harmonics amplitude of the basic undulator field. Thus the alternative between higher field amplitude or pure sinusoidal field exists. The behavior of the undulator field amplitude and harmonics structure for a large set of (undulator gap)/(undulator wavelength) values is demonstrated.

  3. Numerical Relativity Beyond Astrophysics

    OpenAIRE

    Garfinkle, David

    2016-01-01

    Though the main applications of computer simulations in relativity are to astrophysical systems such as black holes and neutron stars, nonetheless there are important applications of numerical methods to the investigation of general relativity as a fundamental theory of the nature of space and time. This paper gives an overview of some of these applications. In particular we cover (i) investigations of the properties of spacetime singularities such as those that occur in the interior of black...

  4. Numerical representations in primates.

    OpenAIRE

    Hauser, M D; MacNeilage, P; M. Ware

    1996-01-01

    Research has demonstrated that human infants and nonhuman primates have a rudimentary numerical system that enables them to count objects or events. More recently, however, studies using a preferential looking paradigm have suggested that preverbal human infants are capable of simple arithmetical operations, such as adding and subtracting a small number of visually presented objects. These findings implicate a relatively sophisticated representational system in the absence of language. To exp...

  5. Numerical Relativity: A review

    OpenAIRE

    Lehner, Luis

    2001-01-01

    Computer simulations are enabling researchers to investigate systems which are extremely difficult to handle analytically. In the particular case of General Relativity, numerical models have proved extremely valuable for investigations of strong field scenarios and been crucial to reveal unexpected phenomena. Considerable efforts are being spent to simulate astrophysically relevant simulations, understand different aspects of the theory and even provide insights in the search for a quantum th...

  6. Handbook of numerical analysis

    CERN Document Server

    Ciarlet, Philippe G

    Mathematical finance is a prolific scientific domain in which there exists a particular characteristic of developing both advanced theories and practical techniques simultaneously. Mathematical Modelling and Numerical Methods in Finance addresses the three most important aspects in the field: mathematical models, computational methods, and applications, and provides a solid overview of major new ideas and results in the three domains. Coverage of all aspects of quantitative finance including models, computational methods and applications Provides an overview of new ideas an

  7. Climate Adaptation in Europe

    International Nuclear Information System (INIS)

    At the Conference of Parties in Copenhagen, Denmark, December 7-18, 2009 Change Magazine will present a special issue on 'Climate Adaptation in Europe'. The magazine contains articles on climate policy strategies in European countries and cross-border studies on climate change, articles on climate adaptation in the Alps, on water quality as a bottleneck for the agricultural sector, and drought in the mediterranean countries. How will member countries in the European Union tackle the climate crisis?.

  8. Arctic Climate Tipping Points

    OpenAIRE

    Lenton, Timothy M.

    2012-01-01

    There is widespread concern that anthropogenic global warming will trigger Arctic climate tipping points. The Arctic has a long history of natural, abrupt climate changes, which together with current observations and model projections, can help us to identify which parts of the Arctic climate system might pass future tipping points. Here the climate tipping points are defined, noting that not all of them involve bifurcations leading to irreversible change. Past abrupt climate changes in the A...

  9. Cosmic Rays and Climate

    OpenAIRE

    Kirkby, Jasper

    2008-01-01

    Among the most puzzling questions in climate change is that of solar-climate variability, which has attracted the attention of scientists for more than two centuries. Until recently, even the existence of solar-climate variability has been controversial - perhaps because the observations had largely involved temporary correlations between climate and the sunspot cycle. Over the last few years, however, diverse reconstructions of past climate change have revealed clear associations with cosmic...

  10. Mathematics of Climate Change

    OpenAIRE

    Halstadtrø, Ida

    2013-01-01

    Mathematics in climate research is rarely mentioned in the everyday conversations or in the media when talking about climate changes. This thesis therefore focus on the central role mathematics plays in climate research, through describing the different models used in predicting future weather and climate. In Chapter 1, a general introduction to climate, its components and feedbacks, and today's status is given. Chapter 2 concentrates on the dynamical models represented by ordinary differenti...

  11. Use of air/ground heat exchangers for heating and cooling of buildings - in-situ measurements, analytical modeling, numerical simulation and system analysis[Dissertation 3357]; Utilisation des echangeurs air/sol pour le chauffage et le rafraichissement des batiments. Mesures in situ, modelisation analytique, simulation numerique et analyse systemique

    Energy Technology Data Exchange (ETDEWEB)

    Hollmuller, P.

    2002-07-01

    In this thesis, physical properties and practical implementation of air/ground heat exchangers were studied. These exchangers consist in ducts placed in the upper ground layer (up to a depth of several meters). Air is circulated through the ducts, with heat transfer from and to the surrounding earth/sand/gravel material, with heat diffusion (conductive and capacitive effects) through this material. Air/ground heat exchangers are used to preheat or cool the air needed by the ventilation system of a building (open loop systems), or to heat up or cool the air in a greenhouse (closed loop systems). The reported study consisted in: (i) case studies of built examples, by detailed measuring and monitoring and data analysis. (ii) modeling the basic system. (iii) solving the basic equations both numerically (by computerized simulation) and analytically. (iv) identifying the basic features of these systems. (v) establishing recommendations for the practical implementation, especially in what regards sizing. It turned out that daily and seasonal heat storage/delivery by means of an air/ground heat exchanger have to be considered separately, with ad hoc rules of thumb each. Depending on parameter values a phase shift by as much as half the period may even be observed, with very little damping of the temperature oscillation. In Switzerland the main relevance for these systems is for improving thermal comfort in buildings in the summer time when outdoor temperature is higher than 26 {sup o}C, and for damping the amplitude of day/night temperature variations in horticultural greenhouses. The work carried out can be considered as of basic relevance for all applications of the systems studied.

  12. Building an advanced climate model: Program plan for the CHAMMP (Computer Hardware, Advanced Mathematics, and Model Physics) Climate Modeling Program

    Energy Technology Data Exchange (ETDEWEB)

    1990-12-01

    The issue of global warming and related climatic changes from increasing concentrations of greenhouse gases in the atmosphere has received prominent attention during the past few years. The Computer Hardware, Advanced Mathematics, and Model Physics (CHAMMP) Climate Modeling Program is designed to contribute directly to this rapid improvement. The goal of the CHAMMP Climate Modeling Program is to develop, verify, and apply a new generation of climate models within a coordinated framework that incorporates the best available scientific and numerical approaches to represent physical, biogeochemical, and ecological processes, that fully utilizes the hardware and software capabilities of new computer architectures, that probes the limits of climate predictability, and finally that can be used to address the challenging problem of understanding the greenhouse climate issue through the ability of the models to simulate time-dependent climatic changes over extended times and with regional resolution.

  13. Analyse

    DEFF Research Database (Denmark)

    Dubgaard, Alex

    2009-01-01

    Restriktioner over for landbruget er en god forretning. Til gengæld kan det ikke betale sig at reducere udledningen af drivhusgasser......Restriktioner over for landbruget er en god forretning. Til gengæld kan det ikke betale sig at reducere udledningen af drivhusgasser...

  14. Application of RUNTA code in flood analyses

    International Nuclear Information System (INIS)

    Flood probability analyses carried out to date indicate the need to evaluate a large number of flood scenarios. This necessity is due to a variety of reasons, the most important of which include: - Large number of potential flood sources - Wide variety of characteristics of flood sources - Large possibility of flood-affected areas becoming inter linked, depending on the location of the potential flood sources - Diversity of flood flows from one flood source, depending on the size of the rupture and mode of operation - Isolation times applicable - Uncertainties in respect of the structural resistance of doors, penetration seals and floors - Applicable degrees of obstruction of floor drainage system Consequently, a tool which carries out the large number of calculations usually required in flood analyses, with speed and flexibility, is considered necessary. The RUNTA Code enables the range of possible scenarios to be calculated numerically, in accordance with all those parameters which, as a result of previous flood analyses, it is necessary to take into account in order to cover all the possible floods associated with each flood area

  15. Rate of return requirement for climate versus petroleum projects

    OpenAIRE

    Emhjellen, Magne; Osmundsen, Petter

    2012-01-01

    Many sosio-economic rates of returns for climate projects have been used in analysing the present value of the climate benefit. However, little attention has been devoted to profitability assessments based on commercial considerations. Economic valuation of climate projects, seen from the perspective of a commercial company, is the subject of this article. In particular, we examine the required rate of return for a project where the uncertainty in the CO2 quota price is the main market uncert...

  16. The Effects of Climate Change on Harp Seals (Pagophilus groenlandicus)

    OpenAIRE

    Johnston, David W.; Bowers, Matthew T.; Ari S. Friedlaender; David M. Lavigne

    2012-01-01

    Harp seals (Pagophilus groenlandicus) have evolved life history strategies to exploit seasonal sea ice as a breeding platform. As such, individuals are prepared to deal with fluctuations in the quantity and quality of ice in their breeding areas. It remains unclear, however, how shifts in climate may affect seal populations. The present study assesses the effects of climate change on harp seals through three linked analyses. First, we tested the effects of short-term climate variability on yo...

  17. Climate Impacts on Agriculture: A Challenge to Complacency?

    OpenAIRE

    Frank Ackerman; Stanton, Elizabeth A.

    2013-01-01

    Recent research paints an ominous picture of climate impacts on agriculture, in contrast to the relative optimism of research from the 1990s. Continued use of the earlier research findings, in economic models and policy analyses, contributes to an unwarranted complacency about the urgency of climate policy. Earlier research concluded that the initial stages of climate change would bring net benefits to global agriculture, thanks to carbon fertilization and longer growing seasons in high-latit...

  18. Novethic explains the links between climate and finance

    International Nuclear Information System (INIS)

    The COP 21 conference is the stage for UN climate negotiations among countries and has elicited unprecedented involvement by economic and financial players. For more than a year now, Novethic has been analysing and quantifying the move to incorporate the climate into financial management, a movement that counts nearly 1,000 investors representing Euro 30 trillion. Novethic has prepared four quick guides to ending coal investments, green financing, carbon risk and the climate commitments of the systemic banks and insurance companies

  19. The carbon rent economics of climate policy

    International Nuclear Information System (INIS)

    By reducing the demand for fossil fuels, climate policy can reduce scarcity rents for fossil resource owners. As mitigation policies ultimately aim to limit emissions, a new scarcity for “space” in the atmosphere to deposit emissions is created. The associated scarcity rent, or climate rent (that is, for example, directly visible in permit prices under an emission trading scheme) can be higher or lower than the original fossil resource rent. In this paper, we analyze analytically and numerically the impact of mitigation targets, resource availability, backstop costs, discount rates and demand parameters on fossil resource rents and the climate rent. We assess whether and how owners of oil, gas and coal can be compensated by a carbon permit grandfathering rule. One important finding is that reducing (cumulative) fossil resource use could actually increase scarcity rents and benefit fossil resource owners under a permit grandfathering rule. For our standard parameter setting overall scarcity rents under climate policy increase slightly. While low discount rates of resource owners imply higher rent losses due to climate policies, new developments of reserves or energy efficiency improvements could more than double scarcity rents under climate policy. Another important implication is that agents receiving the climate rent (regulating institutions or owners of grandfathered permits) could influence the climate target such that rents are maximized, rather than to limit global warming to a socially desirable level. For our basic parameter setting, rents would be maximized at approximately 650 GtC emissions (50% of business-as-usual emissions) implying a virtual certainty of exceeding a 2 °C target and a likelihood of 4 °C warming. - Highlights: • Fossil resource rents form a substantial share of the global GDP. • Fossil resource owners can benefit from climate policy. • Climate targets might be influenced by rent-maximizing aspects

  20. Funding climate adaptation strategies with climate derivatives

    Directory of Open Access Journals (Sweden)

    L. Richard Little

    2015-01-01

    Full Text Available Climate adaptation requires large capital investments that could be provided not only by traditional sources like governments and banks, but also by derivatives markets. Such markets would allow two parties with different tolerances and expectations about climate risks to transact for their mutual benefit and, in so doing, finance climate adaptation. Here we calculate the price of a derivative called a European put option, based on future sea surface temperature (SST in Tasmania, Australia, with an 18 °C strike threshold. This price represents a quantifiable indicator of climate risk, and forms the basis for aquaculture industries exposed to the risk of higher SST to finance adaptation strategies through the sale of derivative contracts. Such contracts provide a real incentive to parties with different climate outlooks, or risk exposure to take a market assessment of climate change.