Sample records for improve climate models

  1. Improvement of snowpack simulations in a regional climate model

    SciTech Connect (OSTI)

    Jin, J.; Miller, N.L.

    2011-01-10T23:59:59.000Z

    To improve simulations of regional-scale snow processes and related cold-season hydroclimate, the Community Land Model version 3 (CLM3), developed by the National Center for Atmospheric Research (NCAR), was coupled with the Pennsylvania State University/NCAR fifth-generation Mesoscale Model (MM5). CLM3 physically describes the mass and heat transfer within the snowpack using five snow layers that include liquid water and solid ice. The coupled MM5–CLM3 model performance was evaluated for the snowmelt season in the Columbia River Basin in the Pacific Northwestern United States using gridded temperature and precipitation observations, along with station observations. The results from MM5–CLM3 show a significant improvement in the SWE simulation, which has been underestimated in the original version of MM5 coupled with the Noah land-surface model. One important cause for the underestimated SWE in Noah is its unrealistic land-surface structure configuration where vegetation, snow and the topsoil layer are blended when snow is present. This study demonstrates the importance of the sheltering effects of the forest canopy on snow surface energy budgets, which is included in CLM3. Such effects are further seen in the simulations of surface air temperature and precipitation in regional weather and climate models such as MM5. In addition, the snow-season surface albedo overestimated by MM5–Noah is now more accurately predicted by MM5–CLM3 using a more realistic albedo algorithm that intensifies the solar radiation absorption on the land surface, reducing the strong near-surface cold bias in MM5–Noah. The cold bias is further alleviated due to a slower snowmelt rate in MM5–CLM3 during the early snowmelt stage, which is closer to observations than the comparable components of MM5–Noah. In addition, the over-predicted precipitation in the Pacific Northwest as shown in MM5–Noah is significantly decreased in MM5 CLM3 due to the lower evaporation resulting from the longer snow duration.

  2. IMPROVING PREDICTIONS OF CLIMATE CHANGE: OBSERVATIONAL AND MODELING REQUIREMENTS

    E-Print Network [OSTI]

    in the atmosphere, largely because of emissions from fossil fuel combustion. An increase in atmospheric CO2 would, Brookhaven National Laboratory, Upton NY 11973 USA (ses@bnl.gov) Carbon dioxide (CO2) is building up is the extent of climate change that will result from future increases in atmospheric CO2. Confident knowledge

  3. Improving the Simulation of the West African Monsoon Using the MIT Regional Climate Model

    E-Print Network [OSTI]

    Im, Eun-Soon

    This paper presents an evaluation of the performance of the Massachusetts Institute of Technology (MIT) regional climate model (MRCM) in simulating the West African monsoon. The MRCM is built on the Regional Climate Model, ...

  4. Refining climate models

    ScienceCinema (OSTI)

    Warren, Jeff; Iversen, Colleen; Brooks, Jonathan; Ricciuto, Daniel

    2014-06-26T23:59:59.000Z

    Using dogwood trees, Oak Ridge National Laboratory researchers are gaining a better understanding of the role photosynthesis and respiration play in the atmospheric carbon dioxide cycle. Their findings will aid computer modelers in improving the accuracy of climate simulations.

  5. Refining climate models

    SciTech Connect (OSTI)

    Warren, Jeff; Iversen, Colleen; Brooks, Jonathan; Ricciuto, Daniel

    2012-10-31T23:59:59.000Z

    Using dogwood trees, Oak Ridge National Laboratory researchers are gaining a better understanding of the role photosynthesis and respiration play in the atmospheric carbon dioxide cycle. Their findings will aid computer modelers in improving the accuracy of climate simulations.

  6. Improving the representation of terrestrial ecosystem processes in Earth system models to increase the quality of climate model projections and inform DOE's energy decisions

    E-Print Network [OSTI]

    Improving the representation of terrestrial ecosystem processes in Earth system models to increase results are incorporated into Earth system models to improve climate projections. e overarching goal of TES is to improve the representation of terrestrial ecosystem processes in Earth system models

  7. Global Climate Modeling of the Martian water cycle with improved microphysics and radiatively active water ice clouds

    E-Print Network [OSTI]

    Navarro, Thomas; Forget, François; Spiga, Aymeric; Millour, Ehouarn; Montmessin, Franck

    2013-01-01T23:59:59.000Z

    Radiative effects of water ice clouds have noteworthy consequences on the Martian atmosphere, its thermal structure and circulation. Accordingly, the inclusion of such effects in the LMD Mars Global Climate Model (GCM) greatly modifies the simulated Martian water cycle. The intent of this paper is to address the impact of radiatively active clouds on atmospheric water vapor and ice in the GCM and improve its representation. We propose a new enhanced modeling of the water cycle, consisting of detailed cloud microphysics with dynamic condensation nuclei and a better implementation of perennial surface water ice. This physical modeling is based on tunable parameters. This new version of the GCM is compared to the Thermal Emission Spectrometer observations of the water cycle. Satisfying results are reached for both vapor and cloud opacities. However, simulations yield a lack of water vapor in the tropics after Ls=180{\\deg} which is persistent in simulations compared to observations, as a consequence of aphelion c...

  8. Global distribution and climate forcing of marine organic aerosol: 1. Model improvements and evaluation

    SciTech Connect (OSTI)

    Meskhidze, N.; Xu, J.; Gantt, Brett; Zhang, Yang; Nenes, Athanasios; Ghan, Steven J.; Liu, Xiaohong; Easter, Richard C.; Zaveri, Rahul A.

    2011-11-23T23:59:59.000Z

    Marine organic aerosol emissions have been implemented and evaluated within the National Center of Atmospheric Research (NCAR)'s Community Atmosphere Model (CAM5) with the Pacific Northwest National Laboratory's 7-mode Modal Aerosol Module (MAM-7). Emissions of marine primary organic aerosols (POA), phytoplanktonproduced isoprene- and monoterpenes-derived secondary organic aerosols (SOA) and methane sulfonate (MS{sup -}) are shown to affect surface concentrations of organic aerosols in remote marine regions. Global emissions of submicron marine POA is estimated to be 7.9 and 9.4 Tg yr{sup -1}, for the Gantt et al. (2011) and Vignati et al. (2010) emission parameterizations, respectively. Marine sources of SOA and particulate MS{sup -} (containing both sulfur and carbon atoms) contribute an additional 0.2 and 5.1 Tg yr{sup -1}, respectively. Widespread areas over productive waters of the Northern Atlantic, Northern Pacific, and the Southern Ocean show marine-source submicron organic aerosol surface concentrations of 100 ngm{sup -3}, with values up to 400 ngm{sup -3} over biologically productive areas. Comparison of long-term surface observations of water insoluble organic matter (WIOM) with POA concentrations from the two emission parameterizations shows that despite revealed discrepancies (often more than a factor of 2), both Gantt et al. (2011) and Vignati et al. (2010) formulations are able to capture the magnitude of marine organic aerosol concentrations, with the Gantt et al. (2011) parameterization attaining better seasonality. Model simulations show that the mixing state of the marine POA can impact the surface number concentration of cloud condensation nuclei (CCN). The largest increases (up to 20 %) in CCN (at a supersaturation (S) of 0.2 %) number concentration are obtained over biologically productive ocean waters when marine organic aerosol is assumed to be externally mixed with sea-salt. Assuming marine organics are internally-mixed with sea-salt provides diverse results with increases and decreases in the concentration of CCN over different parts of the ocean. The sign of the CCN change due to the addition of marine organics to seasalt aerosol is determined by the relative significance of the increase in mean modal diameter due to addition of mass, and the decrease in particle hygroscopicity due to compositional changes in marine aerosol. Based on emerging evidence for increased CCN concentration over biologically active surface ocean areas/periods, our study suggests that treatment of sea spray in global climate models (GCMs) as an internal mixture of marine organic aerosols and sea-salt will likely lead to an underestimation in CCN number concentration.

  9. Regional Climate Modeling: Progress, Challenges, and Prospects

    SciTech Connect (OSTI)

    Wang, Yuqing; Leung, Lai R.; McGregor, John L.; Lee, Dong-Kyou; Wang, Wei-Chyung; Ding, Yihui; Kimura, Fujio

    2004-12-01T23:59:59.000Z

    Regional climate modeling with regional climate models (RCMs) has matured over the past decade and allows for meaningful utilization in a broad spectrum of applications. In this paper, latest progresses in regional climate modeling studies are reviewed, including RCM development, applications of RCMs to dynamical downscaling for climate change assessment, seasonal climate predictions and climate process studies, and the study of regional climate predictability. Challenges and potential directions of future research in this important area are discussed, with the focus on those to which less attention has been given previously, such as the importance of ensemble simulations, further development and improvement of regional climate modeling approach, modeling extreme climate events and sub-daily variation of clouds and precipitation, model evaluation and diagnostics, applications of RCMs to climate process studies and seasonal predictions, and development of regional earth system models. It is believed that with both the demonstrated credibility of RCMs’ capability in reproducing not only monthly to seasonal mean climate and interannual variability but also the extreme climate events when driven by good quality reanalysis and the continuous improvements in the skill of global general circulation models (GCMs) in simulating large-scale atmospheric circulation, regional climate modeling will remain an important dynamical downscaling tool for providing the needed information for assessing climate change impacts and seasonal climate predictions, and a powerful tool for improving our understanding of regional climate processes. An internationally coordinated effort can be developed with different focuses by different groups to advance regional climate modeling studies. It is also recognized that since the final quality of the results from nested RCMs depends in part on the realism of the large-scale forcing provided by GCMs, the reduction of errors and improvement in physics parameterizations in both GCMs and RCMs remain a priority for climate modeling community.

  10. A National Strategy for Advancing Climate Modeling

    SciTech Connect (OSTI)

    Dunlea, Edward; Elfring, Chris

    2012-12-04T23:59:59.000Z

    Climate models are the foundation for understanding and projecting climate and climate-related changes and are thus critical tools for supporting climate-related decision making. This study developed a holistic strategy for improving the nationâ??s capability to accurately simulate climate and related Earth system changes on decadal to centennial timescales. The committeeâ??s report is a high level analysis, providing a strategic framework to guide progress in the nationâ??s climate modeling enterprise over the next 10-20 years. This study was supported by DOE, NSF, NASA, NOAA, and the intelligence community.

  11. Sandia National Laboratories: Accelerated Climate Modeling for...

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Accelerated Climate Modeling for Energy New Project Is the ACME of Computer Science to Address Climate Change On December 3, 2014, in Analysis, Climate, Global Climate & Energy,...

  12. Climate Modeling using High-Performance Computing

    SciTech Connect (OSTI)

    Mirin, A A

    2007-02-05T23:59:59.000Z

    The Center for Applied Scientific Computing (CASC) and the LLNL Climate and Carbon Science Group of Energy and Environment (E and E) are working together to improve predictions of future climate by applying the best available computational methods and computer resources to this problem. Over the last decade, researchers at the Lawrence Livermore National Laboratory (LLNL) have developed a number of climate models that provide state-of-the-art simulations on a wide variety of massively parallel computers. We are now developing and applying a second generation of high-performance climate models. Through the addition of relevant physical processes, we are developing an earth systems modeling capability as well.

  13. Climate and Institutional Change ADVANCE efforts to improve

    E-Print Network [OSTI]

    Sheridan, Jennifer

    #12;Climate and Institutional Change ADVANCE efforts to improve departmental climate #12;Why Climate? Recruitment--women more likely to come to a department with good climate Retention--women faculty more likely to stay in a department with good climate Advancement--women more likely to be promoted

  14. Ensemble climate predictions using climate models and observational constraints

    E-Print Network [OSTI]

    REVIEW Ensemble climate predictions using climate models and observational constraints BY PETER A. STOTT 1,* AND CHRIS E. FOREST 2 1 Hadley Centre for Climate Change (Reading Unit), Meteorology Building for constraining climate predictions based on observations of past climate change. The first uses large ensembles

  15. ``Climate Modelling & Global Change'' scientific report ``Climate Modelling & Global Change'' Team

    E-Print Network [OSTI]

    ``Climate Modelling & Global Change'' scientific report ``Climate Modelling & Global Change'' Team) : : : : : : : : : : : : : : : : : 6 2.2 Anthropogenic climate change studies: scenario experiments (96) : : : : : : : : : 7 2 following its creation, the ``Climate Modelling & Global Change'' team had to make its proofs in order

  16. Developing Models for Predictive Climate Science

    SciTech Connect (OSTI)

    Drake, John B [ORNL; Jones, Philip W [Los Alamos National Laboratory (LANL)

    2007-01-01T23:59:59.000Z

    The Community Climate System Model results from a multi-agency collaboration designed to construct cutting-edge climate science simulation models for a broad research community. Predictive climate simulations are currently being prepared for the petascale computers of the near future. Modeling capabilities are continuously being improved in order to provide better answers to critical questions about Earth's climate. Climate change and its implications are front page news in today's world. Could global warming be responsible for the July 2006 heat waves in Europe and the United States? Should more resources be devoted to preparing for an increase in the frequency of strong tropical storms and hurricanes like Katrina? Will coastal cities be flooded due to a rise in sea level? The National Climatic Data Center (NCDC), which archives all weather data for the nation, reports that global surface temperatures have increased over the last century, and that the rate of increase is three times greater since 1976. Will temperatures continue to climb at this rate, will they decline again, or will the rate of increase become even steeper? To address such a flurry of questions, scientists must adopt a systematic approach and develop a predictive framework. With responsibility for advising on energy and technology strategies, the DOE is dedicated to advancing climate research in order to elucidate the causes of climate change, including the role of carbon loading from fossil fuel use. Thus, climate science--which by nature involves advanced computing technology and methods--has been the focus of a number of DOE's SciDAC research projects. Dr. John Drake (ORNL) and Dr. Philip Jones (LANL) served as principal investigators on the SciDAC project, 'Collaborative Design and Development of the Community Climate System Model for Terascale Computers.' The Community Climate System Model (CCSM) is a fully-coupled global system that provides state-of-the-art computer simulations of the Earth's past, present, and future climate states. The collaborative SciDAC team--including over a dozen researchers at institutions around the country--developed, validated, documented, and optimized the performance of CCSM using the latest software engineering approaches, computational technology, and scientific knowledge. Many of the factors that must be accounted for in a comprehensive model of the climate system are illustrated in figure 1.

  17. ``Climate Modelling & Global Change'' scientific report 1 ``Climate Modelling & Global Change'' Team

    E-Print Network [OSTI]

    ``Climate Modelling & Global Change'' scientific report 1 ``Climate Modelling & Global Change of the tropical climate : : : : : : : : : : : : : : : : : : : : : 6 2.2 Short­term variability studies : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : 8 2.3 Climate drift sensitivity studies

  18. UNCORRECTED Grid geometry effects on convection in ocean climate models

    E-Print Network [OSTI]

    Kuhlbrodt, Till

    UNCORRECTED PROOF Grid geometry effects on convection in ocean climate models: a conceptual study is the 12 improvement of convection parameterization schemes, but the question of grid geometry also plays to an at- 14 mosphere model. Such ocean climate models have mostly structured, coarsely resolved grids. 15

  19. Climate Survey Original TemplateClimate Survey Original TemplateClimate Survey Original TemplateClimate Survey Original Template The Chair of the Department of DEPT NAME, NAME, is dedicated to improving workplace climate in your office. As part

    E-Print Network [OSTI]

    Sheridan, Jennifer

    Climate Survey Original TemplateClimate Survey Original TemplateClimate Survey Original TemplateClimate Survey Original Template The Chair of the Department of DEPT NAME, NAME, is dedicated to improving Survey Original TemplateClimate Survey Original TemplateClimate Survey Original TemplateClimate Survey

  20. Climate System Model Plan (2000-2005)

    E-Print Network [OSTI]

    Community Climate System Model Plan (2000-2005) Prepared by the CCSM Scientific Steering Committee Development of the Climate System Model B. 300-Year Fully Coupled Control Simulation C. Simulation System Model Plan (2000-2005). The evolution of the NCAR Community Climate Model (CCM) from an atmosphere

  1. Supercomputers Fuel Global High-Resolution Climate Models

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Supercomputers Fuel Global High-Resolution Climate Models Supercomputers Fuel Global High-Resolution Climate Models Berkeley Lab Researcher Says Climate Science is Entering New...

  2. Statistics and Climate Models Cari Kaufman

    E-Print Network [OSTI]

    we get.") · Some ways that climate might change: (Source: Andrew Gettelman, NCAR) SAMSI Undergraduate Workshop, May 2007 4 #12;Models in Climate Change Assessment Summary for Policymakers IPCC WGI Fourth models and observational constraints. {Figures 10.4 and 10.29} (Source: IPCC, Climate Change 2007

  3. 3, 11331166, 2007 Glacier-climate model

    E-Print Network [OSTI]

    Paris-Sud XI, Université de

    of the Past Reconstructing glacier-based climates of LGM Europe and Russia ­ Part 1: Numerical modelling for climate change the LGM is a popular time period for testing the ability of GCMs to simulate past cli-25CPD 3, 1133­1166, 2007 Glacier-climate model for recosntructing palaeoclimates R. Allen et al

  4. Questions of bias in climate models

    SciTech Connect (OSTI)

    Smith, Steven J.; Wigley, Tom M.; Meinshausen, Malte; Rogelj, Joeri

    2014-08-27T23:59:59.000Z

    The recent work by Shindell usefully contributes to the debate over estimating climate sensitivity by highlighting an important aspect of the climate system: that climate forcings that occur over land result in a more rapid temperature response than forcings that are distributed more uniformly over the globe. While, as noted in this work, simple climate models may be biased by assuming the same temperature response for all forcing agents, the implication that the MAGICC model is biased in this way is not correct.

  5. Sandia Energy - Global Climate Models

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative1 First Use of Energy for All Purposes (Fuel and Nonfuel), 2002; Level: National5Sales for4,645U.S. DOE Office of Scienceand RequirementsCoatingsUltra-High-Voltage SiliconEnergyFailureGlobal Climate Models Home

  6. Development of Frameworks for Robust Regional Climate Modeling PRINCIPAL INVESTIGATOR: Moetasim Ashfaq

    E-Print Network [OSTI]

    goals of climate modeling. Water supports the ecosystems as well as a wide range of human activities to improve region- al predictions of the hydrologic cycle to address climate change impacts, adaptationDevelopment of Frameworks for Robust Regional Climate Modeling PRINCIPAL INVESTIGATOR: Moetasim

  7. Modeling Water, Climate, Agriculture, and the Economy

    E-Print Network [OSTI]

    Yu, Winston

    Describes two models used in the integrated modeling framework designed to study water, climate, agriculture and the economy in Pakistan's Indus Basin: (1) the Indus Basin Model Revised (IBMR-1012), a hydro-economic ...

  8. The Los Alamos coupled climate model

    SciTech Connect (OSTI)

    Jones, P.W.; Malone, R.C.; Lai, C.A.

    1998-12-31T23:59:59.000Z

    To gain a full understanding of the Earth`s climate system, it is necessary to understand physical processes in the ocean, atmosphere, land and sea ice. In addition, interactions between components are very important and models which couple all of the components into a single coupled climate model are required. A climate model which couples ocean, sea ice, atmosphere and land components is described. The component models are run as autonomous processes coupled to a flux coupler through a flexible communications library. Performance considerations of the model are examined, particularly for running the model on distributed-shared-memory machine architectures.

  9. ARM Climate Modeling Best Estimate Data, A New Data Product for Climate Studies

    SciTech Connect (OSTI)

    Xie, Shaocheng [Lawrence Livermore National Laboratory (LLNL); McCoy, Renata B. [Lawrence Livermore National Laboratory (LLNL); Klein, Stephen A. [Lawrence Livermore National Laboratory (LLNL); Cederwall, Richard T. [Lawrence Livermore National Laboratory (LLNL); Wiscombe, Warren J. [Brookhaven National Laboratory (BNL); Clothiaux, Eugene E. [Pennsylvania State University, University Park, PA; Gaustad, Krista L. [Pacific Northwest National Laboratory (PNNL); Golaz, Jean-Christophe [NOAA Geophysical Fluid Dynamics Laboratory (GFDL), Princeton, NJ; Shamblin, Stefanie H [ORNL; Jensen, Michael P. [Brookhaven National Laboratory (BNL); Johnson, Karen L. [Brookhaven National Laboratory (BNL); Lin, Yanluan [NOAA Geophysical Fluid Dynamics Laboratory (GFDL), Princeton, NJ; Long, Charles N. [Pacific Northwest National Laboratory (PNNL); Mather, James H. [Pacific Northwest National Laboratory (PNNL); McCord, Raymond A [ORNL; McFarlane, Sally A. [Pacific Northwest National Laboratory (PNNL); Palanisamy, Giri [ORNL; Shi, Yan [Pacific Northwest National Laboratory (PNNL); Turner, David D. [University of Wisconsin, Madison

    2010-01-01T23:59:59.000Z

    The U.S. Department of Energy (DOE) Atmospheric Radiation Measurement (ARM) Program (www.arm.gov) was created in 1989 to address scientific uncertainties related to global climate change, with a focus on the crucial role of clouds and their influence on the transfer of radiation in the atmosphere. A central activity is the acquisition of detailed observations of clouds and radiation, as well as related atmospheric variables for climate model evaluation and improvement. Since 1992, ARM has established six permanent ARM Climate Research Facility (ACRF) sites and deployed an ARM Mobile Facility (AMF) in diverse climate regimes around the world (Fig. 1) to perform long-term continuous field measurements. The time record of ACRF data now exceeds a decade at most ACRF fixed sites and ranges from several months to one year for AMF deployments. Billions of measurements are currently stored in millions of data files in the ACRF Data Archive. The long-term continuous ACRF data provide invaluable information to improve our understanding of the interaction between clouds and radiation, and an observational basis for model validation and improvement and climate studies. Given the huge number of data files and current diversity of archived ACRF data structures, however, it can be difficult for an outside user such as a climate modeler to quickly find the ACRF data product(s) that best meets their research needs. The required geophysical quantities may exist in multiple data streams, and over the history of ACRF operations, the measurements could be obtained by a variety of instruments, reviewed with different levels of data quality assurance, or derived using different algorithms. In addition, most ACRF data are stored in daily-based files with a temporal resolution that ranges from a few seconds to a few minutes, which is much finer than that sought by some users. Therefore, it is not as convenient for data users to perform quick comparisons over large spans of data, and this can hamper the use of ACRF data by the climate community. To make ACRF data better serve the needs of climate studies and model development, ARM has developed a data product specifically tailored for use by the climate community. The new data product, named the Climate Modeling Best Estimate (CMBE) dataset, assembles those quantities that are both well observed by ACRF over many years and are often used in model evaluation into one single dataset. The CMBE product consists of hourly averages and thus has temporal resolution comparable to a typical resolution used in climate model output. It also includes standard deviations within the averaged hour and quality control flags for the selected quantities to indicate the temporal variability and data quality. Since its initial release in February 2008, the new data product has quickly drawn the attention of the climate modeling community. It is being used for model evaluation by two major U.S. climate modeling centers, the National Center for Atmospheric Research (NCAR) and the Geophysical Fluid Dynamics Laboratory (GFDL). The purpose of this paper is to provide an overview of CMBE data and a few examples that demonstrate the potential value of CMBE data for climate modeling and in studies of cloud processes and climate variability and change.

  10. The Community Climate System Model Version 4

    SciTech Connect (OSTI)

    Gent, Peter R.; Danabasoglu, Gokhan; Donner, Leo J.; Holland, Marika M.; Hunke, Elizabeth C.; Jayne, Steve R.; Lawrence, David M.; Neale, Richard; Rasch, Philip J.; Vertenstein, Mariana; Worley, Patrick; Yang, Zong-Liang; Zhang, Minghua

    2011-10-01T23:59:59.000Z

    The fourth version of the Community Climate System Model (CCSM4) was recently completed and released to the climate community. This paper describes developments to all the CCSM components, and documents fully coupled pre-industrial control runs compared to the previous version, CCSM3. Using the standard atmosphere and land resolution of 1{sup o} results in the sea surface temperature biases in the major upwelling regions being comparable to the 1.4{sup o} resolution CCSM3. Two changes to the deep convection scheme in the atmosphere component result in the CCSM4 producing El Nino/Southern Oscillation variability with a much more realistic frequency distribution than the CCSM3, although the amplitude is too large compared to observations. They also improve the representation of the Madden-Julian Oscillation, and the frequency distribution of tropical precipitation. A new overflow parameterization in the ocean component leads to an improved simulation of the deep ocean density structure, especially in the North Atlantic. Changes to the CCSM4 land component lead to a much improved annual cycle of water storage, especially in the tropics. The CCSM4 sea ice component uses much more realistic albedos than the CCSM3, and the Arctic sea ice concentration is improved in the CCSM4. An ensemble of 20th century simulations runs produce an excellent match to the observed September Arctic sea ice extent from 1979 to 2005. The CCSM4 ensemble mean increase in globally-averaged surface temperature between 1850 and 2005 is larger than the observed increase by about 0.4 C. This is consistent with the fact that the CCSM4 does not include a representation of the indirect effects of aerosols, although other factors may come into play. The CCSM4 still has significant biases, such as the mean precipitation distribution in the tropical Pacific Ocean, too much low cloud in the Arctic, and the latitudinal distributions of short-wave and long-wave cloud forcings.

  11. Climate Impact of Transportation A Model Comparison

    SciTech Connect (OSTI)

    Girod, Bastien; Van Vuuren, Detlef; Grahn, Maria; Kitous, Alban; Kim, Son H.; Kyle, G. Page

    2013-06-01T23:59:59.000Z

    Transportation contributes to a significant and rising share of global energy use and GHG emissions. Therefore modeling future travel demand, its fuel use, and resulting CO2 emission is highly relevant for climate change mitigation. In this study we compare the baseline projections for global service demand (passenger-kilometers, ton-kilometers), fuel use, and CO2 emissions of five different global transport models using harmonized input assumptions on income and population. For four models we also evaluate the impact of a carbon tax. All models project a steep increase in service demand over the century. Technology is important for limiting energy consumption and CO2 emissions, but quite radical changes in the technology mix are required to stabilize or reverse the trend. While all models project liquid fossil fuels dominating up to 2050, they differ regarding the use of alternative fuels (natural gas, hydrogen, biofuels, and electricity), because of different fuel price projections. The carbon tax of US$200/tCO2 in 2050 stabilizes or reverses global emission growth in all models. Besides common findings many differences in the model assumptions and projections indicate room for improvement in modeling and empirical description of the transport system.

  12. Climate Insights 101 Questions and Discussion Points: Module 1, Lesson 4: An Introduction to Climate Modelling

    E-Print Network [OSTI]

    Pedersen, Tom

    Climate Insights 101 Questions and Discussion Points: Module 1, Lesson 4: An Introduction to Climate Modelling 1 Climate Insights 101 Questions and Discussion Points Module 1, Lesson 4: An Introduction to Climate Modelling Available at http://pics.uvic.ca/education/climate-insights-101 Updated May

  13. Constructive Contrasts Between Modeled and Measured Climate

    E-Print Network [OSTI]

    Hargrove, William W.

    Constructive Contrasts Between Modeled and Measured Climate Responses Over a Regional Scale of simulated net primary production (NPP) to climate variables and the response observed in field measurements of NPP. Residual contrasts com- pared deviations of NPP from the empirical surface to identify groupings

  14. Climate change and uncertainty in ecological niche modeling

    E-Print Network [OSTI]

    Alvarez, Otto

    2011-01-01T23:59:59.000Z

    in California." Journal of Climate 8(3): 606- Elith, J. , C.vegetation model for use with climate models: concepts andthe suitability of spatial climate data sets." International

  15. Climate Forcings and Climate Sensitivities Diagnosed from Coupled Climate Model Integrations

    SciTech Connect (OSTI)

    Forster, P M A F; Taylor, K E

    2006-07-25T23:59:59.000Z

    A simple technique is proposed for calculating global mean climate forcing from transient integrations of coupled Atmosphere Ocean General Circulation Models (AOGCMs). This 'climate forcing' differs from the conventionally defined radiative forcing as it includes semi-direct effects that account for certain short timescale responses in the troposphere. Firstly, we calculate a climate feedback term from reported values of 2 x CO{sub 2} radiative forcing and surface temperature time series from 70-year simulations by twenty AOGCMs. In these simulations carbon dioxide is increased by 1%/year. The derived climate feedback agrees well with values that we diagnose from equilibrium climate change experiments of slab-ocean versions of the same models. These climate feedback terms are associated with the fast, quasi-linear response of lapse rate, clouds, water vapor and albedo to global surface temperature changes. The importance of the feedbacks is gauged by their impact on the radiative fluxes at the top of the atmosphere. We find partial compensation between longwave and shortwave feedback terms that lessens the inter-model differences in the equilibrium climate sensitivity. There is also some indication that the AOGCMs overestimate the strength of the positive longwave feedback. These feedback terms are then used to infer the shortwave and longwave time series of climate forcing in 20th and 21st Century simulations in the AOGCMs. We validate the technique using conventionally calculated forcing time series from four AOGCMs. In these AOGCMs the shortwave and longwave climate forcings we diagnose agree with the conventional forcing time series within {approx}10%. The shortwave forcing time series exhibit order of magnitude variations between the AOGCMs, differences likely related to how both natural forcings and/or anthropogenic aerosol effects are included. There are also factor of two differences in the longwave climate forcing time series, which may indicate problems with the modeling of well-mixed-greenhouse-gas changes. The simple diagnoses we present provide an important and useful first step for understanding differences in AOGCM integrations, indicating that some of the differences in model projections can be attributed to different prescribed climate forcing, even for so-called standard climate change scenarios.

  16. Climate Analysis, Monitoring, and Modeling

    E-Print Network [OSTI]

    facing California, with projected impacts reaching every sector of the state's economy and public health. The energy sector will not be spared. The potential repercussions of climate change include frequent heat waves, increased energy consumption, reduced hydropower generation in the summer season

  17. Constraining climate model properties using optimal fingerprint detection methods

    E-Print Network [OSTI]

    Forest, Chris Eliot.; Allen, Myles R.; Sokolov, Andrei P.; Stone, Peter H.

    We present a method for constraining key properties of the climate system that are important for climate prediction (climate sensitivity and rate of heat penetration into the deep ocean) by comparing a model's response to ...

  18. Constraining Climate Model Parameters from Observed 20th Century Changes

    E-Print Network [OSTI]

    Forest, Chris Eliot

    We present revised probability density functions for climate model parameters (effective climate sensitivity, the rate of deep-ocean heat uptake, and the strength of the net aerosol forcing) that are based on climate change ...

  19. Application of Improved Radiation Modeling to General Circulation Models

    SciTech Connect (OSTI)

    Michael J Iacono

    2011-04-07T23:59:59.000Z

    This research has accomplished its primary objectives of developing accurate and efficient radiation codes, validating them with measurements and higher resolution models, and providing these advancements to the global modeling community to enhance the treatment of cloud and radiative processes in weather and climate prediction models. A critical component of this research has been the development of the longwave and shortwave broadband radiative transfer code for general circulation model (GCM) applications, RRTMG, which is based on the single-column reference code, RRTM, also developed at AER. RRTMG is a rigorously tested radiation model that retains a considerable level of accuracy relative to higher resolution models and measurements despite the performance enhancements that have made it possible to apply this radiation code successfully to global dynamical models. This model includes the radiative effects of all significant atmospheric gases, and it treats the absorption and scattering from liquid and ice clouds and aerosols. RRTMG also includes a statistical technique for representing small-scale cloud variability, such as cloud fraction and the vertical overlap of clouds, which has been shown to improve cloud radiative forcing in global models. This development approach has provided a direct link from observations to the enhanced radiative transfer provided by RRTMG for application to GCMs. Recent comparison of existing climate model radiation codes with high resolution models has documented the improved radiative forcing capability provided by RRTMG, especially at the surface, relative to other GCM radiation models. Due to its high accuracy, its connection to observations, and its computational efficiency, RRTMG has been implemented operationally in many national and international dynamical models to provide validated radiative transfer for improving weather forecasts and enhancing the prediction of global climate change.

  20. Climate modeler David Stainforth. Photo courtesy of David Stainforth.

    E-Print Network [OSTI]

    Stevenson, Paul

    Climate modeler David Stainforth. Photo courtesy of David Stainforth. 3. SCIENCE: Intrepid British climate modeler sets out to win over doubters (07/19/2011) Jeremy Lovell, E&E European correspondent the climate debate by explaining why uncertainty has to be a part of the computerized climate models

  1. Hydrologic Response to Climate Variability, Climate Change, and Climate Extreme in the U.S.: Climate Model Evaluation and Projections

    SciTech Connect (OSTI)

    Leung, Lai R.; Qian, Yun

    2005-08-01T23:59:59.000Z

    Water resources are sensitive to climate variability and change; predictions of seasonal to interannual climate variations and projections of long-term climate trends can provide significant values in managing water resources. This study examines the control (1975–1995) and future (1995–2100) climate simulated by a global climate model (GCM) and a regional climate simulation driven by the GCM control simulation for the U.S. Comparison of the regional climate simulation with observations across 13 subregions showed that the simulation captured the seasonality and the distributions of precipitation rate quite well. The GCM control and climate change simulations showed that, as a result of a 1% increase in greenhouse gas concentrations per year, there will be a warming of 2–3°C across the U.S. from 2000 to 2100. Although precipitation is not projected to change during this century, the warming trend will increase evapotranspiration to reduce annual basin mean runoff over five subregions along the coastal and south-central U.S.

  2. Atmospheric Climate Model Experiments Performed at Multiple Horizontal Resolutions

    SciTech Connect (OSTI)

    Phillips, T; Bala, G; Gleckler, P; Lobell, D; Mirin, A; Maxwell, R; Rotman, D

    2007-12-21T23:59:59.000Z

    This report documents salient features of version 3.3 of the Community Atmosphere Model (CAM3.3) and of three climate simulations in which the resolution of its latitude-longitude grid was systematically increased. For all these simulations of global atmospheric climate during the period 1980-1999, observed monthly ocean surface temperatures and sea ice extents were prescribed according to standard Atmospheric Model Intercomparison Project (AMIP) values. These CAM3.3 resolution experiments served as control runs for subsequent simulations of the climatic effects of agricultural irrigation, the focus of a Laboratory Directed Research and Development (LDRD) project. The CAM3.3 model was able to replicate basic features of the historical climate, although biases in a number of atmospheric variables were evident. Increasing horizontal resolution also generally failed to ameliorate the large-scale errors in most of the climate variables that could be compared with observations. A notable exception was the simulation of precipitation, which incrementally improved with increasing resolution, especially in regions where orography plays a central role in determining the local hydroclimate.

  3. Comments on: Global Climate Models

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative1 First Use of Energy for All Purposes (Fuel and Nonfuel), 2002; Level: National5Sales for4,645 3,625govInstrumentstdmadapInactiveVisiting the TWPSuccessAlamosCharacterization2Climate,CobaltColdin679April

  4. The Community Land Model and Its Climate Statistics as a Component of the Community Climate System Model

    E-Print Network [OSTI]

    Hoffman, Forrest M.

    to the Fourth Assessment Report (AR4) by the Intergovernmental Panel on Climate Change [IPCC; i.e., the followThe Community Land Model and Its Climate Statistics as a Component of the Community Climate System carried out with the new version of the Community Climate System Model (CCSM). This paper reports

  5. Improved steamflood analytical model

    E-Print Network [OSTI]

    Chandra, Suandy

    2006-10-30T23:59:59.000Z

    two field cases, a 45x23x8 model was used that represented 1/8 of a 10-acre 5-spot pattern unit, using typical rock and reservoir fluid properties. In the SPE project case, three models were used: 23x12x12 (2.5 ac), 31x16x12 (5 ac) and 45x23x8 (10 ac...

  6. Determining Greenland Ice Sheet sensitivity to regional climate change: one-way coupling of a 3-D thermo-mechanical ice sheet model with a mesoscale climate model

    E-Print Network [OSTI]

    Schlegel, Nicole-Jeanne

    2011-01-01T23:59:59.000Z

    ice sheet model with a mesoscale climate model By Nicole-ice sheet model with a mesoscale climate model Copyrightice sheet model with a mesoscale climate model by Nicole-

  7. LINKING MICROBES TO CLIMATE: INCORPORATING MICROBIAL ACTIVITY INTO CLIMATE MODELS COLLOQUIUM

    SciTech Connect (OSTI)

    DeLong, Edward; Harwood, Caroline; Reid, Ann

    2011-01-01T23:59:59.000Z

    This report explains the connection between microbes and climate, discusses in general terms what modeling is and how it applied to climate, and discusses the need for knowledge in microbial physiology, evolution, and ecology to contribute to the determination of fluxes and rates in climate models. It recommends with a multi-pronged approach to address the gaps.

  8. Towards Ultra-High Resolution Models of Climate and Weather

    E-Print Network [OSTI]

    Wehner, Michael; Oliker, Leonid; Shalf, John

    2008-01-01T23:59:59.000Z

    Models of Climate and Weather Michael Wehner, Leonid Oliker,modeling climate change and weather prediction is one of thedelity in both short term weather prediction and long term

  9. Improving understanding of climate change dynamics using interactive simulations

    E-Print Network [OSTI]

    Martin Aguirre, Juan Francisco

    2008-01-01T23:59:59.000Z

    Global climate change is one of the most complex problems that human kind will face during the 21st century. Long delays in changing greenhouse gas emissions and in the response of the climate to anthropogenic forcing mean ...

  10. Improving the Water Component of an Agricultural Climate Change Assessment : Issues from the Standpoint of Agricultural Economists

    E-Print Network [OSTI]

    McCarl, Bruce A.

    Improving the Water Component of an Agricultural Climate Change Assessment : Issues from The National Global Climate Change Research Program is supporting appraisals of water and agriculture among assessment. Key Terms; Economics, Climate Change Assessment, Agriculture, Irrigation, Water use tradeoffs

  11. Improving the Assessment and Valuation of Climate Change Impacts for Policy and Regulatory Analysis

    SciTech Connect (OSTI)

    Marten, Alex; Kopp, Robert E.; Shouse, Kate C.; Griffiths, Charles; Hodson, Elke L.; Kopits, Elizabeth; Mignone, Bryan K.; Moore, Chris; Newbold, Steve; Waldhoff, Stephanie T.; Wolverton, Ann

    2013-04-01T23:59:59.000Z

    The social cost of carbon (SCC) is a monetized metric for evaluating the benefits associated with marginal reductions in carbon dioxide (CO2) emissions. It represents the expected welfare loss from the future damages caused by the release of one tonne of CO2 in a given year, expressed in consumption equivalent terms. It is intended to be a comprehensive measure, taking into account changes in agricultural productivity, human health risks, loss of ecosystem services and biodiversity, and the frequency and severity of flooding and storms, among other possible impacts. Estimating the SCC requires long-term modeling of global economic activity, the climate system, and the linkages between the two through anthropogenic greenhouse gas (GHG) emissions and the effects of changing climatic conditions on economic activity and human well-being. The United States government currently uses the SCC in regulatory benefit-cost analyses to assess the welfare effects of changes in CO2 emissions. Consistent application of the SCC to federal rulemaking analyses began in 2009-2010 with the development of a set of global SCC estimates that employed three prominent integrated assessment models (IAMs) -- DICE, FUND, and PAGE. The U.S. government report identified a number of limitations associated with SCC estimates in general and its own assumptions in particular: an incomplete treatment of damages, including potential “catastrophic” impacts; uncertainty regarding the extrapolation of damage functions to high temperatures; incomplete treatment of adaptation and technological change; and the evaluation of uncertain outcomes in a risk-neutral fashion. External experts have identified other potential issues, including how best to model long-term socio-economic and emissions pathways, oversimplified physical climate and carbon cycle modeling within the IAMs, and an inconsistency between non-constant economic growth scenarios and constant discount rates. The U.S. government has committed to updating the estimates regularly as modeling capabilities and scientific and economic knowledge improves. To help foster further improvements in estimating the SCC, the U.S. Environmental Protection Agency and the U.S. Department of Energy hosted a pair of workshops on “Improving the Assessment and Valuation of Climate Change Impacts for Policy and Regulatory Analysis.” The first focused on conceptual and methodological issues related to integrated assessment modeling and the second brought together natural and social scientists to explore methods for improving damage assessment for multiple sectors. These two workshops provide the basis for the 13 papers in this special issue.

  12. Studying the Causes of Recent Climate Change Program for Climate Model Diagnosis and Intercomparison

    E-Print Network [OSTI]

    Kammen, Daniel M.

    1 Studying the Causes of Recent Climate Change Ben Santer Program for Climate Model Diagnosis of evidence suggests a discernible human influence on global climate" "There is new and stronger evidence that most of the warming observed over the last 50 years is attributable to human activities" "Most

  13. Chemistry climate model simulations of1 spring Antarctic ozone

    E-Print Network [OSTI]

    Wirosoetisno, Djoko

    Chemistry climate model simulations of1 spring Antarctic ozone 1234567 89A64BC7DEF72B4 19B34EE3293C climate model simulations of spring Antarctic ozone John Austin,1,2 H. Struthers,3 J. Scinocca,4 D. A) and Intergovernmental Panel on Climate Change A1b Scenario. The simulations of the Antarctic ozone hole are compared

  14. Modeling Climate Change Adaptation: Challenges, Recent Developments and Future Directions

    E-Print Network [OSTI]

    Wing, Ian Sue

    Modeling Climate Change Adaptation: Challenges, Recent Developments and Future Directions Karen of modeling practice in the field of integrated assessment of climate change and ways forward. Past efforts assessments of climate change have concentrated on developing baseline emissions scenarios and analyzing

  15. Climate Multi-model Regression Using Spatial Smoothing Karthik Subbian

    E-Print Network [OSTI]

    Banerjee, Arindam

    Climate Multi-model Regression Using Spatial Smoothing Karthik Subbian Arindam Banerjee Abstract There are several Global Climate Models (GCMs) reported by var- ious countries to the Intergovernmental Panel on Climate Change (IPCC). Due to the varied nature of the GCM assumptions, the fu- ture projections

  16. Climate Sensitivity of the Community Climate System Model, Version 4 Atmospheric Sciences, University of Washington, Seattle, Washington

    E-Print Network [OSTI]

    Reif, Rafael

    Climate Sensitivity of the Community Climate System Model, Version 4 C. M. BITZ Atmospheric climate sensitivity of the Community Climate System Model, version 4 (CCSM4) is 3.208C for 18 horizontal). The transient climate sensitivity of CCSM4 at 18 resolution is 1.728C, which is about 0.28C higher than in CCSM3

  17. Atmospheric Tides in the Latest Generation of Climate Models

    E-Print Network [OSTI]

    Covey, Curt

    For atmospheric tides driven by solar heating, the database of climate model output used in the most recent assessment report of the Intergovernmental Panel on Climate Change (IPCC) confirms and extends the authors’ earlier ...

  18. A Framework for Modeling Uncertainty in Regional Climate Change

    E-Print Network [OSTI]

    Monier, Erwan

    In this study, we present a new modeling framework and a large ensemble of climate projections to investigate the uncertainty in regional climate change over the US associated with four dimensions of uncertainty. The sources ...

  19. Parameterization of Urban Characteristics for Global Climate Modeling

    E-Print Network [OSTI]

    Jackson, Trisha L.

    2011-10-31T23:59:59.000Z

    of varying scales and effects of climate change on urban populations, urbanization must be included in global climate models (GCMs). To properly capture the spatial variability in urban areas, GCMs require global databases of urban extent and characteristics...

  20. Sandia National Laboratories: Climate

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    from improved climate models to performance models for underground waste storage to 3D printing and digital rock physics. Marianne Walck (Director ... NASA Award for Marginal...

  1. Sensitivity of climate models: Comparison of simulated and observed patterns for past climates. Progress report, February 1, 1992--January 31, 1993

    SciTech Connect (OSTI)

    Prell, W.L.; Webb, T. III

    1992-08-01T23:59:59.000Z

    Predicting the potential climatic effects of increased concentrations of atmospheric carbon dioxide requires the continuing development of climate models. Confidence in the predictions will be much enhanced once the models are thoroughly tested in terms of their ability to simulate climates that differ significantly from today`s climate. As one index of the magnitude of past climate change, the global mean temperature increase during the past 18,000 years is similar to that predicted for carbon dioxide--doubling. Simulating the climatic changes of the past 18,000 years, as well as the warmer-than-present climate of 6000 years ago and the climate of the last interglacial, around 126,000 years ago, provides an excellent opportunity to test the models that are being used in global climate change research. During the past several years, we have used paleoclimatic data to test the accuracy of the National Center for Atmospheric Research, Community Climate Model, Version 0, after changing its boundary conditions to those appropriate for past climates. We have assembled regional and near-global paleoclimatic data sets of pollen, lake level, and marine plankton data and calibrated many of the data in terms of climatic variables. We have also developed methods that permit direct quantitative comparisons between the data and model results. Our research has shown that comparing the model results with the data is an evolutionary process, because the models, the data, and the methods for comparison are continually being improved. During 1992, we have completed new modeling experiments, further analyzed previous model experiments, compiled new paleodata, made new comparisons between data and model results, and participated in workshops on paleoclimatic modeling.

  2. COLLABORATIVE RESEARCH: TOWARDS ADVANCED UNDERSTANDING AND PREDICTIVE CAPABILITY OF CLIMATE CHANGE IN THE ARCTIC USING A HIGH-RESOLUTION REGIONAL ARCTIC CLIMATE SYSTEM MODEL

    SciTech Connect (OSTI)

    Gutowski, William J.

    2013-02-07T23:59:59.000Z

    The motivation for this project was to advance the science of climate change and prediction in the Arctic region. Its primary goals were to (i) develop a state-of-the-art Regional Arctic Climate system Model (RACM) including high-resolution atmosphere, land, ocean, sea ice and land hydrology components and (ii) to perform extended numerical experiments using high performance computers to minimize uncertainties and fundamentally improve current predictions of climate change in the northern polar regions. These goals were realized first through evaluation studies of climate system components via one-way coupling experiments. Simulations were then used to examine the effects of advancements in climate component systems on their representation of main physics, time-mean fields and to understand variability signals at scales over many years. As such this research directly addressed some of the major science objectives of the BER Climate Change Research Division (CCRD) regarding the advancement of long-term climate prediction.

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

    SciTech Connect (OSTI)

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

    2013-06-28T23:59:59.000Z

    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. Cpl6: The New Extensible, High-Performance Parallel Coupler forthe Community Climate System Model

    SciTech Connect (OSTI)

    Craig, Anthony P.; Jacob, Robert L.; Kauffman, Brain; Bettge,Tom; Larson, Jay; Ong, Everest; Ding, Chris; He, Yun

    2005-03-24T23:59:59.000Z

    Coupled climate models are large, multiphysics applications designed to simulate the Earth's climate and predict the response of the climate to any changes in the forcing or boundary conditions. The Community Climate System Model (CCSM) is a widely used state-of-art climate model that has released several versions to the climate community over the past ten years. Like many climate models, CCSM employs a coupler, a functional unit that coordinates the exchange of data between parts of climate system such as the atmosphere and ocean. This paper describes the new coupler, cpl6, contained in the latest version of CCSM,CCSM3. Cpl6 introduces distributed-memory parallelism to the coupler, a class library for important coupler functions, and a standardized interface for component models. Cpl6 is implemented entirely in Fortran90 and uses Model Coupling Toolkit as the base for most of its classes. Cpl6 gives improved performance over previous versions and scales well on multiple platforms.

  5. Thunderstorms in a changing climate: A cloudresolving modeling study

    E-Print Network [OSTI]

    Maccabe, Barney

    prediction of surface water and groundwater dynamics under projected climate change scenarios Thunderstorms in a changing climate: A cloudresolving modeling study Joseph Galewsky@unm.edu One of the potential impacts of a changing climate is an increase in the severity of thunderstorms

  6. Climate, Ocean and Sea Ice Modeling (COSIM)

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative1 First Use of Energy for All Purposes (Fuel and Nonfuel), 2002; Level: National5Sales for4,645 3,625govInstrumentstdmadapInactiveVisiting the TWPSuccessAlamosCharacterization2Climate, Ocean and Sea Ice Modeling

  7. Subtask 2.4 - Integration and Synthesis in Climate Change Predictive Modeling

    SciTech Connect (OSTI)

    Jaroslav Solc

    2009-06-01T23:59:59.000Z

    The Energy & Environmental Research Center (EERC) completed a brief evaluation of the existing status of predictive modeling to assess options for integration of our previous paleohydrologic reconstructions and their synthesis with current global climate scenarios. Results of our research indicate that short-term data series available from modern instrumental records are not sufficient to reconstruct past hydrologic events or predict future ones. On the contrary, reconstruction of paleoclimate phenomena provided credible information on past climate cycles and confirmed their integration in the context of regional climate history is possible. Similarly to ice cores and other paleo proxies, acquired data represent an objective, credible tool for model calibration and validation of currently observed trends. It remains a subject of future research whether further refinement of our results and synthesis with regional and global climate observations could contribute to improvement and credibility of climate predictions on a regional and global scale.

  8. Introduction Improved Model Alternative Statistical Model

    E-Print Network [OSTI]

    Regression Linear "Linear" is for the parameter(s) e.g. yi = 0 +1xi +i Non-linear "Non-linear Square Regression Linear "Linear" is for the parameter(s) e.g. yi = 0 +1xi +i #12;Introduction Improved Model Recall of Ordinary Least-Square Regression Least Square Regression Linear "Linear

  9. Final Progress Report [Testing Climate Model Simulations of Tropical Cirrus Lifecycles: A Lagrangian

    SciTech Connect (OSTI)

    Soden, Brian J

    2009-06-30T23:59:59.000Z

    This project integrates ARM data sets with satellite observations and model simulations to improve the representation of tropical cloud systems in climate models. We focus on describing and understanding relevant features of the lifecycle of tropical cirrus cloud systems using an innovative method which combines the Eulerian-based ARM measurements with Lagrangian information from geostationary satellites.

  10. Regional-Scale Climate Change: Observations and Model Simulations

    SciTech Connect (OSTI)

    Raymond S. Bradley; Henry F. Diaz

    2010-12-14T23:59:59.000Z

    This collaborative proposal addressed key issues in understanding the Earthâ??s climate system, as highlighted by the U.S. Climate Science Program. The research focused on documenting past climatic changes and on assessing future climatic changes based on suites of global and regional climate models. Geographically, our emphasis was on the mountainous regions of the world, with a particular focus on the Neotropics of Central America and the Hawaiian Islands. Mountain regions are zones where large variations in ecosystems occur due to the strong climate zonation forced by the topography. These areas are particularly susceptible to changes in critical ecological thresholds, and we conducted studies of changes in phonological indicators based on various climatic thresholds.

  11. The rapidly evolving field of decadal climate prediction, using initialized climate models to produce time-evolving predictions of regional climate, is producing new results for

    E-Print Network [OSTI]

    , and it is on those time scales of interest to water managers that decadal climate prediction is being appliedThe rapidly evolving field of decadal climate prediction, using initialized climate models to produce time-evolving predictions of regional climate, is producing new results for predictions

  12. Historical and idealized climate model experiments: an intercomparison of Earth system models of intermediate complexity

    E-Print Network [OSTI]

    Monier, Erwan

    Both historical and idealized climate model experiments are performed with a variety of Earth system models of intermediate complexity (EMICs) as part of a community contribution to the Intergovernmental Panel on Climate ...

  13. Sandia National Laboratories: improving PV performance model...

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    accuracy PV Performance Modeling Collaborative's New and Improved Website Is Launched On December 10, 2014, in Computational Modeling & Simulation, Energy, Facilities, News, News &...

  14. Sandia National Laboratories: improving PV performance model...

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    technical rigor PV Performance Modeling Collaborative's New and Improved Website Is Launched On December 10, 2014, in Computational Modeling & Simulation, Energy, Facilities, News,...

  15. Climate Change Modeling and Downscaling Issues and Methodological Perspectives for the U.S. National Climate Assessment

    SciTech Connect (OSTI)

    Janetos, Anthony C.; Collins, William D.; Wuebbles, D.J.; Diffenbaugh, Noah; Hayhoe, Katharine; Hibbard, Kathleen A.; Hurtt, George

    2012-03-31T23:59:59.000Z

    This is the full workshop report for the modeling workshop we did for the National Climate Assessment, with DOE support.

  16. The Program for climate Model diagnosis and Intercomparison: 20-th anniversary Symposium

    SciTech Connect (OSTI)

    Potter, Gerald L; Bader, David C; Riches, Michael; Bamzai, Anjuli; Joseph, Renu

    2011-01-05T23:59:59.000Z

    Twenty years ago, W. Lawrence (Larry) Gates approached the U.S. Department of Energy (DOE) Office of Energy Research (now the Office of Science) with a plan to coordinate the comparison and documentation of climate model differences. This effort would help improve our understanding of climate change through a systematic approach to model intercomparison. Early attempts at comparing results showed a surprisingly large range in control climate from such parameters as cloud cover, precipitation, and even atmospheric temperature. The DOE agreed to fund the effort at the Lawrence Livermore National Laboratory (LLNL), in part because of the existing computing environment and because of a preexisting atmospheric science group that contained a wide variety of expertise. The project was named the Program for Climate Model Diagnosis and Intercomparison (PCMDI), and it has changed the international landscape of climate modeling over the past 20 years. In spring 2009 the DOE hosted a 1-day symposium to celebrate the twentieth anniversary of PCMDI and to honor its founder, Larry Gates. Through their personal experiences, the morning presenters painted an image of climate science in the 1970s and 1980s, that generated early support from the international community for model intercomparison, thereby bringing PCMDI into existence. Four talks covered Gates���¢��������s early contributions to climate research at the University of California, Los Angeles (UCLA), the RAND Corporation, and Oregon State University through the founding of PCMDI to coordinate the Atmospheric Model Intercomparison Project (AMIP). The speakers were, in order of presentation, Warren Washington [National Center for Atmospheric Research (NCAR)], Kelly Redmond (Western Regional Climate Center), George Boer (Canadian Centre for Climate Modelling and Analysis), and Lennart Bengtsson [University of Reading, former director of the European Centre for Medium-Range Weather Forecasts (ECMWF)]. The afternoon session emphasized the scientific ideas that are the basis of PCMDI���¢��������s success, summarizing their evolution and impact. Four speakers followed the various PCMDI-supported climate model intercomparison projects, beginning with early work on cloud representations in models, presented by Robert D. Cess (Distinguished Professor Emeritus, Stony Brook University), and then the latest Cloud Feedback Model Intercomparison Projects (CFMIPs) led by Sandrine Bony (Laboratoire de M�������©t�������©orologie Dynamique). Benjamin Santer (LLNL) presented a review of the climate change detection and attribution (D & A) work pioneered at PCMDI, and Gerald A. Meehl (NCAR) ended the day with a look toward the future of climate change research.

  17. Graduate Opportunities in Earth Systems Modeling and Climate Impacts on Hydrology and Water Resources

    E-Print Network [OSTI]

    Graduate Opportunities in Earth Systems Modeling and Climate Impacts on Hydrology and Water research assistantships available in the general area of earth systems modeling and climate impacts

  18. [10-386] Assessing and Improving the Scale Dependence of Ecosystem Processes in Earth System Models

    E-Print Network [OSTI]

    . Goodale Cornell U. *Overall Project Lead *Lead Institution Intellectual Merit: Earth system models include policies. Our research assesses and improves Earth system model simulations of the carbon cycle, ecosystem of the Community Climate System Model/Community Earth System Model, which includes statistical meteorological

  19. Investment Dimension: Enhanced Data Equals Better Climate Models

    SciTech Connect (OSTI)

    Roeder, Lynne R.

    2010-11-01T23:59:59.000Z

    Through the American Recovery and Reinvestment Act of 2009, the U.S. Department of Energy provided the Atmospheric Radiation Measurement (ARM) Climate Research Facility with $60 million for new and upgraded instrumentation, equipment, and infrastructure to improve atmospheric data sets. These enhancements will take place among the permanent ARM research sites in Oklahoma and Alaska in the United States, and near the equator in the tropical Western Pacific. They will also advance the capabilities of ARM’s mobile and aerial research platforms. This article focuses on key enhancements - particularly new scanning radars, enhanced lidar technologies, aerosol observation systems, and in situ aircraft probes - that will provide unprecedented data sets for the modeling community.

  20. Climate Determinism Revisited: Multiple Equilibria in a Complex Climate Model

    E-Print Network [OSTI]

    Ferreira, David

    Multiple equilibria in a coupled ocean–atmosphere–sea ice general circulation model (GCM) of an aquaplanet with many degrees of freedom are studied. Three different stable states are found for exactly the same set of ...

  1. Uncertainty in emissions projections for climate models

    E-Print Network [OSTI]

    Webster, Mort David.; Babiker, Mustafa H.M.; Mayer, Monika.; Reilly, John M.; Harnisch, Jochen.; Hyman, Robert C.; Sarofim, Marcus C.; Wang, Chien.

    Future global climate projections are subject to large uncertainties. Major sources of this uncertainty are projections of anthropogenic emissions. We evaluate the uncertainty in future anthropogenic emissions using a ...

  2. RICCI Sophie Global Change and Climate Modeling Team

    E-Print Network [OSTI]

    RICCI Sophie Global Change and Climate Modeling Team CERFACS - Toulouse, FRANCE Technical Report TR covariance matrix#17;. This hypothesis stems from the T S water mass properties conservation over long term

  3. Modeling Water Resource Systems under Climate Change: IGSM-WRS

    E-Print Network [OSTI]

    Strzepek, K.

    Through the integration of a Water Resource System (WRS) component, the MIT Integrated Global System Model (IGSM) framework has been enhanced to study the effects of climate change on managed water-resource systems. ...

  4. Desert dust and anthropogenic aerosol interactions in the Community Climate System Model coupled-carbon-climate model

    SciTech Connect (OSTI)

    Mahowald, Natalie [Cornell University; Rothenberg, D. [Cornell University; Lindsay, Keith [National Center for Atmospheric Research (NCAR); Doney, Scott C. [Woods Hole Oceanographic Institution; Moore, Jefferson Keith [University of California, Irvine; Randerson, James T. [University of California, Irvine; Thornton, Peter E [ORNL; Jones, C. D. [Hadley Center, Devon, England

    2011-02-01T23:59:59.000Z

    Coupled-carbon-climate simulations are an essential tool for predicting the impact of human activity onto the climate and biogeochemistry. Here we incorporate prognostic desert dust and anthropogenic aerosols into the CCSM3.1 coupled carbon-climate model and explore the resulting interactions with climate and biogeochemical dynamics through a series of transient anthropogenic simulations (20th and 21st centuries) and sensitivity studies. The inclusion of prognostic aerosols into this model has a small net global cooling effect on climate but does not significantly impact the globally averaged carbon cycle; we argue that this is likely to be because the CCSM3.1 model has a small climate feedback onto the carbon cycle. We propose a mechanism for including desert dust and anthropogenic aerosols into a simple carbon-climate feedback analysis to explain the results of our and previous studies. Inclusion of aerosols has statistically significant impacts on regional climate and biogeochemistry, in particular through the effects on the ocean nitrogen cycle and primary productivity of altered iron inputs from desert dust deposition.

  5. Improving Availability, Access and Use of Climate Information in Africa: Ethiopia's experience

    E-Print Network [OSTI]

    Miami, University of

    Improving Availability, Access and Use of Climate Information in Africa: Ethiopia's experience Tufa, and it has been declining. The available stations are unevenly distributed with most of them located along the main roads. The available observations suffer from gaps and poor quality. Besides, the available data

  6. Climate simulations and projections with a super-parameterized climate model

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Stan, Cristiana; Xu, Li

    2014-10-01T23:59:59.000Z

    The mean climate and its variability are analyzed in a suite of numerical experiments with a fully coupled general circulation model in which subgrid-scale moist convection is explicitly represented through embedded 2D cloud-system resolving models. Control simulations forced by the present day, fixed atmospheric carbon dioxide concentration are conducted using two horizontal resolutions and validated against observations and reanalyses. The mean state simulated by the higher resolution configuration has smaller biases. Climate variability also shows some sensitivity to resolution but not as uniform as in the case of mean state. The interannual and seasonal variability are better represented in themore »simulation at lower resolution whereas the subseasonal variability is more accurate in the higher resolution simulation. The equilibrium climate sensitivity of the model is estimated from a simulation forced by an abrupt quadrupling of the atmospheric carbon dioxide concentration. The equilibrium climate sensitivity temperature of the model is 2.77 °C, and this value is slightly smaller than the mean value (3.37 °C) of contemporary models using conventional representation of cloud processes. The climate change simulation forced by the representative concentration pathway 8.5 scenario projects an increase in the frequency of severe droughts over most of the North America.« less

  7. Climate simulations and projections with a super-parameterized climate model

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Stan, Cristiana [George Mason Univ., Fairfax, VA (United States). Dept. of Atmospheric, Oceanic and Earth Sciences; Xu, Li [George Mason Univ., Fairfax, VA (United States). Center for Ocean-Land-Atmosphere Studies

    2014-10-01T23:59:59.000Z

    The mean climate and its variability are analyzed in a suite of numerical experiments with a fully coupled general circulation model in which subgrid-scale moist convection is explicitly represented through embedded 2D cloud-system resolving models. Control simulations forced by the present day, fixed atmospheric carbon dioxide concentration are conducted using two horizontal resolutions and validated against observations and reanalyses. The mean state simulated by the higher resolution configuration has smaller biases. Climate variability also shows some sensitivity to resolution but not as uniform as in the case of mean state. The interannual and seasonal variability are better represented in the simulation at lower resolution whereas the subseasonal variability is more accurate in the higher resolution simulation. The equilibrium climate sensitivity of the model is estimated from a simulation forced by an abrupt quadrupling of the atmospheric carbon dioxide concentration. The equilibrium climate sensitivity temperature of the model is 2.77 °C, and this value is slightly smaller than the mean value (3.37 °C) of contemporary models using conventional representation of cloud processes. The climate change simulation forced by the representative concentration pathway 8.5 scenario projects an increase in the frequency of severe droughts over most of the North America.

  8. Modeling the near-term risk of climate uncertainty : interdependencies among the U.S. states.

    SciTech Connect (OSTI)

    Lowry, Thomas Stephen; Tidwell, Vincent Carroll; Backus, George A.; Warren, Drake E.

    2010-12-01T23:59:59.000Z

    Decisions made to address climate change must start with an understanding of the risk of an uncertain future to human systems, which in turn means understanding both the consequence as well as the probability of a climate induced impact occurring. In other words, addressing climate change is an exercise in risk-informed policy making, which implies that there is no single correct answer or even a way to be certain about a single answer; the uncertainty in future climate conditions will always be present and must be taken as a working-condition for decision making. In order to better understand the implications of uncertainty on risk and to provide a near-term rationale for policy interventions, this study estimates the impacts from responses to climate change on U.S. state- and national-level economic activity by employing a risk-assessment methodology for evaluating uncertain future climatic conditions. Using the results from the Intergovernmental Panel on Climate Change's (IPCC) Fourth Assessment Report (AR4) as a proxy for climate uncertainty, changes in hydrology over the next 40 years were mapped and then modeled to determine the physical consequences on economic activity and to perform a detailed 70-industry analysis of the economic impacts among the interacting lower-48 states. The analysis determines industry-level effects, employment impacts at the state level, interstate population migration, consequences to personal income, and ramifications for the U.S. trade balance. The conclusions show that the average risk of damage to the U.S. economy from climate change is on the order of $1 trillion over the next 40 years, with losses in employment equivalent to nearly 7 million full-time jobs. Further analysis shows that an increase in uncertainty raises this risk. This paper will present the methodology behind the approach, a summary of the underlying models, as well as the path forward for improving the approach.

  9. Climate, Ocean and Sea Ice Modeling

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative1 First Use of Energy for All Purposes (Fuel and Nonfuel), 2002; Level: National5Sales for4,645U.S. DOE Office511041clothAdvanced Materials Advanced. C o w l i t zManufacturing: U.S.Climate ActionClimate, EarthOcean

  10. Predicting Improved Chiller Performance Through Thermodynamic Modeling

    E-Print Network [OSTI]

    Figueroa, I. E.; Cathey, M.; Medina, M. A.; Nutter, D. W.

    This paper presents two case studies in which thermodynamic modeling was used to predict improved chiller performance. The model predicted the performance (COP and total energy consumption) of water-cooled centrifugal chillers as a function...

  11. Regional Climate Model Projections for the State of Washington

    SciTech Connect (OSTI)

    Salathe, E.; Leung, Lai-Yung R.; Qian, Yun; Zhang, Yongxin

    2010-05-05T23:59:59.000Z

    Global climate models do not have sufficient spatial resolution to represent the atmospheric and land surface processes that determine the unique regional heterogeneity of the climate of the State of Washington. If future large-scale weather patterns interact differently with the local terrain and coastlines than current weather patterns, local changes in temperature and precipitation could be quite different from the coarse-scale changes projected by global models. Regional climate models explicitly simulate the interactions between the large-scale weather patterns simulated by a global model and the local terrain. We have performed two 100-year climate simulations using the Weather and Research Forecasting (WRF) model developed at the National Center for Atmospheric Research (NCAR). One simulation is forced by the NCAR Community Climate System Model version 3 (CCSM3) and the second is forced by a simulation of the Max Plank Institute, Hamburg, global model (ECHAM5). The mesoscale simulations produce regional changes in snow cover, cloudiness, and circulation patterns associated with interactions between the large-scale climate change and the regional topography and land-water contrasts. These changes substantially alter the temperature and precipitation trends over the region relative to the global model result or statistical downscaling. To illustrate this effect, we analyze the changes from the current climate (1970-1999) to the mid 21st century (2030-2059). Changes in seasonal-mean temperature, precipitation, and snowpack are presented. Several climatological indices of extreme daily weather are also presented: precipitation intensity, fraction of precipitation occurring in extreme daily events, heat wave frequency, growing season length, and frequency of warm nights. Despite somewhat different changes in seasonal precipitation and temperature from the two regional simulations, consistent results for changes in snowpack and extreme precipitation are found in both simulations.

  12. The origins of computer weather prediction and climate modeling

    SciTech Connect (OSTI)

    Lynch, Peter [Meteorology and Climate Centre, School of Mathematical Sciences, University College Dublin, Belfield (Ireland)], E-mail: Peter.Lynch@ucd.ie

    2008-03-20T23:59:59.000Z

    Numerical simulation of an ever-increasing range of geophysical phenomena is adding enormously to our understanding of complex processes in the Earth system. The consequences for mankind of ongoing climate change will be far-reaching. Earth System Models are capable of replicating climate regimes of past millennia and are the best means we have of predicting the future of our climate. The basic ideas of numerical forecasting and climate modeling were developed about a century ago, long before the first electronic computer was constructed. There were several major practical obstacles to be overcome before numerical prediction could be put into practice. A fuller understanding of atmospheric dynamics allowed the development of simplified systems of equations; regular radiosonde observations of the free atmosphere and, later, satellite data, provided the initial conditions; stable finite difference schemes were developed; and powerful electronic computers provided a practical means of carrying out the prodigious calculations required to predict the changes in the weather. Progress in weather forecasting and in climate modeling over the past 50 years has been dramatic. In this presentation, we will trace the history of computer forecasting through the ENIAC integrations to the present day. The useful range of deterministic prediction is increasing by about one day each decade, and our understanding of climate change is growing rapidly as Earth System Models of ever-increasing sophistication are developed.

  13. Long-Term Climate Commitments Projected with ClimateCarbon Cycle Models G.-K. PLATTNER,a,n

    E-Print Network [OSTI]

    Stocker, Thomas

    Long-Term Climate Commitments Projected with Climate­Carbon Cycle Models G.-K. PLATTNER,a,n R IAC, ETH Zürich, Zürich, Switzerland c Potsdam Institute for Climate Impact Research, Potsdam, Germany of Earth and Ocean Sciences, University of Victoria, Victoria, British Columbia, Canada h The Open

  14. Regional climate model data used within the SWURVE project 2: addressing uncertainty in regional climate model data Hydrol. Earth Syst. Sci., 11(1), 10851096, 2007

    E-Print Network [OSTI]

    Boyer, Edmond

    .Ekstrom@uea.ac.uk Abstract To aid assessments of the impact of climate change on water related activities in the case study on the impacts of climate change on specific water management activities (Kilsby, 2007). Uncertainties linked, temperature, rainfall, Europe Introduction As climate model projections are often used in climate change

  15. Climate Modeling using High-Performance Computing The Center for Applied Scientific Computing (CASC) and the LLNL Climate and Carbon

    E-Print Network [OSTI]

    and NCAR in the development of a comprehensive, earth systems model. This model incorporates the most-performance climate models. Through the addition of relevant physical processes, we are developing an earth systems modeling capability as well. Our collaborators in climate research include the National Center

  16. Regional climate models, spatial data and extremes

    E-Print Network [OSTI]

    Nychka, Douglas

    density function. f(y) = eg(y) or g(y) = log(f(y)) we are interested in the (simple) behavior of g when p from five clim forcings due to solar activity and volcanoes. Red shaded bands show the 5­95% range greenhouse gases ­ without Summary figure from Intergovernmental Panel on Climate Change, Fourth Assessement

  17. Regional climate models, spatial data and extremes

    E-Print Network [OSTI]

    Nychka, Douglas

    density function. f(y) = eg(y) or g(y) = log(f(y)) we are interested in the (simple) behavior of g when y bands show the 5­95% range for 19 simulations from five clim forcings due to solar activity Intergovernmental Panel on Climate Change, Fourth Assessement Report. Used as evidence for attributing global

  18. Climate system modeling on massively parallel systems: LDRD Project 95-ERP-47 final report

    SciTech Connect (OSTI)

    Mirin, A.A.; Dannevik, W.P.; Chan, B.; Duffy, P.B.; Eltgroth, P.G.; Wehner, M.F.

    1996-12-01T23:59:59.000Z

    Global warming, acid rain, ozone depletion, and biodiversity loss are some of the major climate-related issues presently being addressed by climate and environmental scientists. Because unexpected changes in the climate could have significant effect on our economy, it is vitally important to improve the scientific basis for understanding and predicting the earth`s climate. The impracticality of modeling the earth experimentally in the laboratory together with the fact that the model equations are highly nonlinear has created a unique and vital role for computer-based climate experiments. However, today`s computer models, when run at desired spatial and temporal resolution and physical complexity, severely overtax the capabilities of our most powerful computers. Parallel processing offers significant potential for attaining increased performance and making tractable simulations that cannot be performed today. The principal goals of this project have been to develop and demonstrate the capability to perform large-scale climate simulations on high-performance computing systems (using methodology that scales to the systems of tomorrow), and to carry out leading-edge scientific calculations using parallelized models. The demonstration platform for these studies has been the 256-processor Cray-T3D located at Lawrence Livermore National Laboratory. Our plan was to undertake an ambitious program in optimization, proof-of-principle and scientific study. These goals have been met. We are now regularly using massively parallel processors for scientific study of the ocean and atmosphere, and preliminary parallel coupled ocean/atmosphere calculations are being carried out as well. Furthermore, our work suggests that it should be possible to develop an advanced comprehensive climate system model with performance scalable to the teraflops range. 9 refs., 3 figs.

  19. Improved Offshore Wind Resource Assessment in Global Climate Stabilization Scenarios

    SciTech Connect (OSTI)

    Arent, D.; Sullivan, P.; Heimiller, D.; Lopez, A.; Eurek, K.; Badger, J.; Jorgensen, H. E.; Kelly, M.; Clarke, L.; Luckow, P.

    2012-10-01T23:59:59.000Z

    This paper introduces a technique for digesting geospatial wind-speed data into areally defined -- country-level, in this case -- wind resource supply curves. We combined gridded wind-vector data for ocean areas with bathymetry maps, country exclusive economic zones, wind turbine power curves, and other datasets and relevant parameters to build supply curves that estimate a country's offshore wind resource defined by resource quality, depth, and distance-from-shore. We include a single set of supply curves -- for a particular assumption set -- and study some implications of including it in a global energy model. We also discuss the importance of downscaling gridded wind vector data to capturing the full resource potential, especially over land areas with complex terrain. This paper includes motivation and background for a statistical downscaling methodology to account for terrain effects with a low computational burden. Finally, we use this forum to sketch a framework for building synthetic electric networks to estimate transmission accessibility of renewable resource sites in remote areas.

  20. Final Report on Evaluating the Representation and Impact of Convective Processes in the NCAR Community Climate System Model

    SciTech Connect (OSTI)

    X. Wu, G. J. Zhang

    2008-04-23T23:59:59.000Z

    Convection and clouds affect atmospheric temperature, moisture and wind fields through the heat of condensation and evaporation and through redistributions of heat, moisture and momentum. Individual clouds have a spatial scale of less than 10 km, much smaller than the grid size of several hundred kilometers used in climate models. Therefore the effects of clouds must be approximated in terms of variables that the model can resolve. Deriving such formulations for convection and clouds has been a major challenge for the climate modeling community due to the lack of observations of cloud and microphysical properties. The objective of our DOE CCPP project is to evaluate and improve the representation of convection schemes developed by PIs in the NCAR (National Center for Atmospheric Research) Community Climate System Model (CCSM) and study its impact on global climate simulations. • The project resulted in nine peer-reviewed publications and numerous scientific presentations that directly address the CCPP’s scientific objective of improving climate models. • We developed a package of improved convection parameterization that includes improved closure, trigger condition for convection, and comprehensive treatment of convective momentum transport. • We implemented the new convection parameterization package into several versions of the NCAR models (both coupled and uncoupled). This has led to 1) Improved simulation of seasonal migration of ITCZ; 2) Improved shortwave cloud radiative forcing response to El Niño in CAM3; 3) Improved MJO simulation in both uncoupled and coupled model; and 4) Improved simulation of ENSO in coupled model. • Using the dynamic core of CCM3, we isolated the dynamic effects of convective momentum transport. • We implemented mosaic treatment of subgrid-scale cloud-radiation interaction in CCM3.

  1. Climate effects of anthropogenic sulfate: Simulations from a coupled chemistry/climate model

    SciTech Connect (OSTI)

    Chuang, C.C.; Penner, J.E.; Taylor, K.E.; Walton, J.J.

    1993-09-01T23:59:59.000Z

    In this paper, we use a more comprehensive approach by coupling a climate model with a 3-D global chemistry model to investigate the forcing by anthropogenic aerosol sulfate. The chemistry model treats the global-scale transport, transformation, and removal of SO{sub 2}, DMS and H{sub 2}SO{sub 4} species in the atmosphere. The mass concentration of anthropogenic sulfate from fossil fuel combustion and biomass burning is calculated in the chemistry model and provided to the climate model where it affects the shortwave radiation. We also investigate the effect, with cloud nucleation parameterized in terms of local aerosol number, sulfate mass concentration and updraft velocity. Our simulations indicate that anthropogenic sulfate may result in important increases in reflected solar radiation, which would mask locally the radiative forcing from increased greenhouse gases. Uncertainties in these results will be discussed.

  2. Arctic ozone loss and climate sensitivity: Updated threedimensional model study

    E-Print Network [OSTI]

    Feng, Wuhu

    Arctic ozone loss and climate sensitivity: Updated three­dimensional model study Chipperfield winter­spring chemical ozone loss from 1991 2003, its observed correlation with low temperatures. CTM throughout studied. The model reproduces large column winters also captures shape of ozone loss profile

  3. A Climate Modelling Primer Building an EBM with Excel

    E-Print Network [OSTI]

    McCready, Mark J.

    A Climate Modelling Primer Building an EBM with Excel 1. Introduction This document tells you how this guide to get the EBM coded up in whatever programming language you have available. To get a fuller understanding of where the equations come from, you'll need a copy of the book handy. 2. The model domain

  4. Estimating present climate in a warming world: a model-based approach

    SciTech Connect (OSTI)

    Raeisaenen, J.; Ruokolainen, L. [University of Helsinki (Finland). Division of Atmospheric Sciences and Geophysics

    2008-09-30T23:59:59.000Z

    Weather services base their operational definitions of 'present' climate on past observations, using a 30-year normal period such as 1961-1990 or 1971-2000. In a world with ongoing global warming, however, past data give a biased estimate of the actual present-day climate. Here we propose to correct this bias with a 'delta change' method, in which model-simulated climate changes and observed global mean temperature changes are used to extrapolate past observations forward in time, to make them representative of present or future climate conditions. In a hindcast test for the years 1991-2002, the method works well for temperature, with a clear improvement in verification statistics compared to the case in which the hindcast is formed directly from the observations for 1961-1990. However, no improvement is found for precipitation, for which the signal-to-noise ratio between expected anthropogenic changes and interannual variability is much lower than for temperature. An application of the method to the present (around the year 2007) climate suggests that, as a geographical average over land areas excluding Antarctica, 8-9 months per year and 8-9 years per decade can be expected to be warmer than the median for 1971-2000. Along with the overall warming, a substantial increase in the frequency of warm extremes at the expense of cold extremes of monthly-to-annual temperature is expected.

  5. Climate Models from the Joint Global Change Research Institute

    DOE Data Explorer [Office of Scientific and Technical Information (OSTI)]

    Staff at the Joint Institute develop and use models to simulate the economic and physical impacts of global change policy options. The GCAM, for example, gives analysts insight into how regional and national economies might respond to climate change mitigation policies including carbon taxes, carbon trading, and accelerated deployment of energy technology. Three available models are Phoenix, GCAM, and EPIC. Phoenix is a global, dynamic recursive, computable general equilibrium model that is solved in five-year time steps from 2005 through 2100 and divides the world into twenty-four regions. Each region includes twenty-six industrial sectors. Particular attention is paid to energy production in Phoenix. There are nine electricity-generating technologies (coal, natural gas, oil, biomass, nuclear, hydro, wind, solar, and geothermal) and four additional energy commodities: crude oil, refined oil products, coal, and natural gas. Phoenix is designed to answer economic questions related to international climate and energy policy and international trade. Phoenix replaces the Second Generation Model (SGM) that was formerly used for general equilibrium analysis at JGCRI. GCAM is the Global Change Assessment Model, a partial equilibrium model of the world with 14 regions. GCAM operates in 5 year time steps from 1990 to 2095 and is designed to examine long-term changes in the coupled energy, agriculture/land-use, and climate system. GCAM includes a 151-region agriculture land-use module and a reduced form carbon cycle and climate module in addition to its incorporation of demographics, resources, energy production and consumption. The model has been used extensively in a number of assessment and modeling activities such as the Energy Modeling Forum (EMF), the U.S. Climate Change Technology Program, and the U.S. Climate Change Science Program and IPCC assessment reports. GCAM is now freely available as a community model. The Environmental Policy Integrated Climate (EPIC) Model is a process-based agricultural systems model composed of simulation components for weather, hydrology, nutrient cycling, pesticide fate, tillage, crop growth, soil erosion, crop and soil management and economics. Staff at PNNL have been involved in the development of this model by integrating new sub-models for soil carbon dynamics and nitrogen cycling.

  6. Sandia National Laboratories: Energy and Climate

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    from improved climate models to performance models for underground waste storage to 3D printing and digital rock physics. Marianne Walck (Director ... Resolving a Key to How...

  7. Sandia National Laboratories: Global Climate & Energy

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    from improved climate models to performance models for underground waste storage to 3D printing and digital rock physics. Marianne Walck (Director ... Sandia Participated in the...

  8. Sandia National Laboratories: Climate/Environment

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    from improved climate models to performance models for underground waste storage to 3D printing and digital rock physics. Marianne Walck (Director ... NASA Award for Marginal...

  9. A multi-resolution method for climate system modeling: application of Spherical Centroidal A multi-resolution method for climate system modeling: Application of Spherical Centroidal Voroni Tessellations

    SciTech Connect (OSTI)

    Ringler, Todd D [Los Alamos National Laboratory; Gunzburger, Max [FLORIDA STATE UNIV; Ju, Lili [UNIV OF SOUTH CAROLINA

    2008-01-01T23:59:59.000Z

    During the next decade and beyond, climate system models will be challenged to resolve scales and processes that are far beyond their current scope. Each climate system component has its prototypical example of an unresolved process that may strongly influence the global climate system, ranging from eddy activity within ocean models, to ice streams within ice sheet models, to surface hydrological processes within land system models, to cloud processes within atmosphere models. These new demands will almost certainly result in the develop of multi-resolution schemes that are able, at least regional to faithfully simulate these fine-scale processes. Spherical Centroidal Voronoi Tessellations (SCVTs) offer one potential path toward the development of robust, multi-resolution climate system component models, SCVTs allow for the generation of high quality Voronoi diagrams and Delaunay triangulations through the use of an intuitive, user-defined density function, each of the examples provided, this method results in high-quality meshes where the quality measures are guaranteed to improve as the number of nodes is increased. Real-world examples are developed for the Greenland ice sheet and the North Atlantic ocean. Idealized examples are developed for ocean-ice shelf interaction and for regional atmospheric modeling. In addition to defining, developing and exhibiting SCVTs, we pair this mesh generation technique with a previously developed finite-volume method. Our numerical example is based on the nonlinear shallow-water equations spanning the entire surface of the sphere. This example is used to elucidate both the potential benefits of this multi-resolution method and the challenges ahead.

  10. IMPROVING THE TREATMENT OF EXTREMES IN THE GENERATION OF CLIMATE CHANGE SCENARIOS

    E-Print Network [OSTI]

    Katz, Richard

    ENSO Dayoftheyear 4 6 8 10 12 14 16 #12;· Software -- R open source statistical programming language weather reflecting climate variability or change · Statistical downscaling of numerical model output desired statistic) Automatic application · Fort Collins, CO, USA July daily precipitation intensities 100

  11. Evaluating the Representation and Impact of Convective Processes in the NCAR’s Community Climate System Model

    SciTech Connect (OSTI)

    Xiaoqing Wu

    2008-07-31T23:59:59.000Z

    Convection and clouds affect atmospheric temperature, moisture and wind fields through the heat of condensation and evaporation and through redistributions of heat, moisture and momentum. Individual clouds have a spatial scale of less than 10 km, much smaller than the grid size of several hundred kilometers used in climate models. Therefore the effects of clouds must be approximated in terms of variables that the model can resolve. Deriving such formulations for convection and clouds has been a major challenge for the climate modeling community due to the lack of observations of cloud and microphysical properties. The objective of our DOE CCPP project is to evaluate and improve the representation of convection schemes developed by PIs in the NCAR (National Center for Atmospheric Research) Community Climate System Model (CCSM) and study its impact on global climate simulations.

  12. MODIS-Derived Boundary Conditions for a Mesoscale Climate Model: Application to Irrigated Agriculture in the Euphrates Basin

    E-Print Network [OSTI]

    Evans, Jason

    -level water consumption were more than doubled relative to simulations that did not incorporate MODIS data to improve the realism of a regional climate model (the fifth-generation Pennsylvania State University­NCAR Mesoscale Model) with respect to irrigated agriculture. MODIS data were used to estimate spatially

  13. Comments on: Climate Measurement & Modeling

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative1 First Use of Energy for All Purposes (Fuel and Nonfuel), 2002; Level: National5Sales for4,645 3,625govInstrumentstdmadapInactiveVisiting the TWPSuccessAlamosCharacterization2Climate,CobaltColdin679April

  14. Sandia Energy - Climate Measurement & Modeling

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative1 First Use of Energy for All Purposes (Fuel and Nonfuel), 2002; Level: National5Sales for4,645 3,625 1,006 492 742EnergyOnItemResearch > TheNuclear Press ReleasesInApplied &Climate Measurement &

  15. The accuracy of climate models' simulated season lengths and the effectiveness of grid scale correction factors

    SciTech Connect (OSTI)

    Winterhalter, Wade

    2011-09-01T23:59:59.000Z

    Global climate change is expected to impact biological populations through a variety of mechanisms including increases in the length of their growing season. Climate models are useful tools for predicting how season length might change in the future. However, the accuracy of these models tends to be rather low at regional geographic scales. Here, I determined the ability of several atmosphere and ocean general circulating models (AOGCMs) to accurately simulate historical season lengths for a temperate ectotherm across the continental United States. I also evaluated the effectiveness of regional-scale correction factors to improve the accuracy of these models. I found that both the accuracy of simulated season lengths and the effectiveness of the correction factors to improve the model's accuracy varied geographically and across models. These results suggest that regional specific correction factors do not always adequately remove potential discrepancies between simulated and historically observed environmental parameters. As such, an explicit evaluation of the correction factors' effectiveness should be included in future studies of global climate change's impact on biological populations.

  16. Aerosols and clouds in chemical transport models and climate models.

    SciTech Connect (OSTI)

    Lohmann,U.; Schwartz, S. E.

    2008-03-02T23:59:59.000Z

    Clouds exert major influences on both shortwave and longwave radiation as well as on the hydrological cycle. Accurate representation of clouds in climate models is a major unsolved problem because of high sensitivity of radiation and hydrology to cloud properties and processes, incomplete understanding of these processes, and the wide range of length scales over which these processes occur. Small changes in the amount, altitude, physical thickness, and/or microphysical properties of clouds due to human influences can exert changes in Earth's radiation budget that are comparable to the radiative forcing by anthropogenic greenhouse gases, thus either partly offsetting or enhancing the warming due to these gases. Because clouds form on aerosol particles, changes in the amount and/or composition of aerosols affect clouds in a variety of ways. The forcing of the radiation balance due to aerosol-cloud interactions (indirect aerosol effect) has large uncertainties because a variety of important processes are not well understood precluding their accurate representation in models.

  17. Developing fast and efficient climate models

    E-Print Network [OSTI]

    Williamson, Mark

    , based on the global model of Tim Lenton. The resulting package comprises an Earth System Model was closely integrated with the GENIE (Grid ENabled Integrated Earth system model) project, funded by the NERC

  18. Increase of Carbon Cycle Feedback with Climate Sensitivity: Results from a coupled Climate and Carbon Cycle Model

    SciTech Connect (OSTI)

    Govindasamy, B; Thompson, S; Mirin, A; Wickett, M; Caldeira, K; Delire, C

    2004-04-01T23:59:59.000Z

    Coupled climate and carbon cycle modeling studies have shown that the feedback between global warming and the carbon cycle, in particular the terrestrial carbon cycle, could accelerate climate change and result in larger warming. In this paper, we investigate the sensitivity of this feedback for year-2100 global warming in the range of 0 K to 8 K. Differing climate sensitivities to increased CO{sub 2} content are imposed on the carbon cycle models for the same emissions. Emissions from the SRES A2 scenario are used. We use a fully-coupled climate and carbon cycle model, the INtegrated Climate and CArbon model (INCCA) the NCAR/DOE Parallel Coupled Model coupled to the IBIS terrestrial biosphere model and a modified-OCMIP ocean biogeochemistry model. In our model, for scenarios with year-2100 global warming increasing from 0 to 8 K, land uptake decreases from 47% to 29% of total CO{sub 2} emissions. Due to competing effects, ocean uptake (16%) shows almost no change at all. Atmospheric CO{sub 2} concentration increases were 48% higher in the run with 8 K global climate warming than in the case with no warming. Our results indicate that carbon cycle amplification of climate warming will be greater if there is higher climate sensitivity to increased atmospheric CO{sub 2} content; the carbon cycle feedback factor increases from 1.13 to 1.48 when global warming increases from 3.2 to 8 K.

  19. An Interactive Multi-Model for Consensus on Climate Change

    SciTech Connect (OSTI)

    Kocarev, Ljupco [University of California, San Diego] [University of California, San Diego

    2014-07-02T23:59:59.000Z

    This project purports to develop a new scheme for forming consensus among alternative climate models, that give widely divergent projections as to the details of climate change, that is more intelligent than simply averaging the model outputs, or averaging with ex post facto weighting factors. The method under development effectively allows models to assimilate data from one another in run time with weights that are chosen in an adaptive training phase using 20th century data, so that the models synchronize with one another as well as with reality. An alternate approach that is being explored in parallel is the automated combination of equations from different models in an expert-system-like framework.

  20. Wildland fire emissions, carbon, and climate: Modeling fuel consumption

    E-Print Network [OSTI]

    rate and pattern. Fuel consumption is the basic process that leads to heat absorbing emissions called evaluated with an independent, quality assured, fuel consumption data set. Furthermore, anecdotal evidenceWildland fire emissions, carbon, and climate: Modeling fuel consumption Roger D. Ottmar U

  1. RHP: HOW CLIMATE MODELS GAIN AND EXERCISE How Climate Models Gain and Exercise Authority

    E-Print Network [OSTI]

    Hulme, Mike

    -dimensional models, intermediate complexity models, general circulation models, and Earth system models. 2 www

  2. Impact of emissions, chemistry, and climate on atmospheric carbon monoxide : 100-year predictions from a global chemistry-climate model

    E-Print Network [OSTI]

    Wang, Chien.; Prinn, Ronald G.

    The possible trends for atmospheric carbon monoxide in the next 100 yr have been illustrated using a coupled atmospheric chemistry and climate model driven by emissions predicted by a global economic development model. ...

  3. Climate change uncertainty evaluation, impacts modelling and resilience of farm scale dynamics in Scotland 

    E-Print Network [OSTI]

    Rivington, Michael

    2011-06-28T23:59:59.000Z

    evidence of how primary production components of agriculture in Scotland may change under a future climate. The work used a generic Integrated Modelling Framework to structure the following sequence of investigations: Evaluate a Regional Climate Model...

  4. Climate Projections Using Bayesian Model Averaging and Space-Time Dependence

    E-Print Network [OSTI]

    Haran, Murali

    Climate Projections Using Bayesian Model Averaging and Space-Time Dependence K. Sham Bhat, Murali Haran, Adam Terando, and Klaus Keller. Abstract Projections of future climatic changes are a key input to the design of climate change mitiga- tion and adaptation strategies. Current climate change projections

  5. Conceptual understanding of climate change with a globally resolved energy balance model

    E-Print Network [OSTI]

    Dommenget, Dietmar

    Conceptual understanding of climate change with a globally resolved energy balance model Dietmar on the surface energy balance by very simple repre- sentations of solar and thermal radiation, the atmospheric and cold regions to warm more than other regions. Keywords Climate dynamics Á Climate change Á Climate

  6. A Gaussian graphical model approach to climate networks

    SciTech Connect (OSTI)

    Zerenner, Tanja, E-mail: tanjaz@uni-bonn.de [Meteorological Institute, University of Bonn, Auf dem Hügel 20, 53121 Bonn (Germany)] [Meteorological Institute, University of Bonn, Auf dem Hügel 20, 53121 Bonn (Germany); Friederichs, Petra; Hense, Andreas [Meteorological Institute, University of Bonn, Auf dem Hügel 20, 53121 Bonn (Germany) [Meteorological Institute, University of Bonn, Auf dem Hügel 20, 53121 Bonn (Germany); Interdisciplinary Center for Complex Systems, University of Bonn, Brühler Straße 7, 53119 Bonn (Germany); Lehnertz, Klaus [Department of Epileptology, University of Bonn, Sigmund-Freud-Straße 25, 53105 Bonn (Germany) [Department of Epileptology, University of Bonn, Sigmund-Freud-Straße 25, 53105 Bonn (Germany); Helmholtz Institute for Radiation and Nuclear Physics, University of Bonn, Nussallee 14-16, 53115 Bonn (Germany); Interdisciplinary Center for Complex Systems, University of Bonn, Brühler Straße 7, 53119 Bonn (Germany)

    2014-06-15T23:59:59.000Z

    Distinguishing between direct and indirect connections is essential when interpreting network structures in terms of dynamical interactions and stability. When constructing networks from climate data the nodes are usually defined on a spatial grid. The edges are usually derived from a bivariate dependency measure, such as Pearson correlation coefficients or mutual information. Thus, the edges indistinguishably represent direct and indirect dependencies. Interpreting climate data fields as realizations of Gaussian Random Fields (GRFs), we have constructed networks according to the Gaussian Graphical Model (GGM) approach. In contrast to the widely used method, the edges of GGM networks are based on partial correlations denoting direct dependencies. Furthermore, GRFs can be represented not only on points in space, but also by expansion coefficients of orthogonal basis functions, such as spherical harmonics. This leads to a modified definition of network nodes and edges in spectral space, which is motivated from an atmospheric dynamics perspective. We construct and analyze networks from climate data in grid point space as well as in spectral space, and derive the edges from both Pearson and partial correlations. Network characteristics, such as mean degree, average shortest path length, and clustering coefficient, reveal that the networks posses an ordered and strongly locally interconnected structure rather than small-world properties. Despite this, the network structures differ strongly depending on the construction method. Straightforward approaches to infer networks from climate data while not regarding any physical processes may contain too strong simplifications to describe the dynamics of the climate system appropriately.

  7. True to Milankovitch: Glacial Inception in the new Community Climate System Model.

    E-Print Network [OSTI]

    Jochum, Markus

    True to Milankovitch: Glacial Inception in the new Community Climate System Model. 1 2 3 4 Markus42 ability of climate models to anticipate the evolution of climate in the future.43 2 #12 Circulation Models (GCMs) have57 failed to reproduce glacial inception, the cooling and increase in snow

  8. Final Report for High Latitude Climate Modeling: ARM Takes Us Beyond Case Studies

    SciTech Connect (OSTI)

    Russell, Lynn M [Scripps/UCSD; Lubin, Dan [Scripps/UCSD

    2013-06-18T23:59:59.000Z

    The main thrust of this project was to devise a method by which the majority of North Slope of Alaska (NSA) meteorological and radiometric data, collected on a daily basis, could be used to evaluate and improve global climate model (GCM) simulations and their parameterizations, particularly for cloud microphysics. Although the standard ARM Program sensors for a less complete suite of instruments for cloud and aerosol studies than the instruments on an intensive field program such as the 2008 Indirect and Semi-Direct Aerosol Campaign (ISDAC), the advantage they offer lies in the long time base and large volume of data that covers a wide range of meteorological and climatological conditions. The challenge has been devising a method to interpret the NSA data in a practical way, so that a wide variety of meteorological conditions in all seasons can be examined with climate models. If successful, climate modelers would have a robust alternative to the usual “case study” approach (i.e., from intensive field programs only) for testing and evaluating their parameterizations’ performance. Understanding climate change on regional scales requires a broad scientific consideration of anthropogenic influences that goes beyond greenhouse gas emissions to also include aerosol-induced changes in cloud properties. For instance, it is now clear that on small scales, human-induced aerosol plumes can exert microclimatic radiative and hydrologic forcing that rivals that of greenhouse gas–forced warming. This project has made significant scientific progress by investigating what causes successive versions of climate models continue to exhibit errors in cloud amount, cloud microphysical and radiative properties, precipitation, and radiation balance, as compared with observations and, in particular, in Arctic regions. To find out what is going wrong, we have tested the models' cloud representation over the full range of meteorological conditions found in the Arctic using the ARM North Slope of Alaska (NSA) data.

  9. Conceptual stochastic climate models Peter Imkeller

    E-Print Network [OSTI]

    Monahan, Adam Hugh

    to be thoroughly inve- stigated but too simple to be treated as quantitatively accurate, through Earth System Models of Intermediate Complexity (EMICs) which represent some clima- te subsystems (e.g. the ocean

  10. COMPARING MODEL RESULTS TO NATIONAL CLIMATE POLICY GOALS: RESULTS FROM THE ASIA MODELING EXERCISE

    SciTech Connect (OSTI)

    Calvin, Katherine V.; Fawcett, Allen A.; Jiang, Kejun

    2012-12-01T23:59:59.000Z

    While the world has yet to adopt a single unified policy to limit climate change, many countries and regions have adopted energy and climate policies that have implications for global emissions. In this paper, we discuss a few key policies and how they are included in a set of 24 energy and integrated assessment models that participated in the Asia Modeling Exercise. We also compare results from these models for a small set of stylized scenarios to the pledges made as part of the Copenhagen Accord and the goals stated by the Major Economies Forum. We find that the targets outlined by the United States, the European Union, Japan, and Korea require significant policy action in most of the models analyzed. For most of the models in the study, however, the goals outlined by India are met without any climate policy. The stringency of climate policy required to meet China’s Copenhagen pledges varies across models and accounting methodologies.

  11. Autonomie Modeling Tool Improves Vehicle Design and Testing,...

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Autonomie Modeling Tool Improves Vehicle Design and Testing, Informs New Fuel Economy Standards Autonomie Modeling Tool Improves Vehicle Design and Testing, Informs New Fuel...

  12. Improvements to Hydrogen Delivery Scenario Analysis Model (HDSAM...

    Office of Environmental Management (EM)

    Improvements to Hydrogen Delivery Scenario Analysis Model (HDSAM) and Results Improvements to Hydrogen Delivery Scenario Analysis Model (HDSAM) and Results This presentation by...

  13. Diagnostic indicators for integrated assessment models of climate policy

    SciTech Connect (OSTI)

    Kriegler, Elmar; Petermann, Nils; Krey, Volker; Schwanitz, Jana; Luderer, Gunnar; Ashina, Shuichi; Bosetti, Valentina; Eom, Jiyong; Kitous, Alban; Mejean, Aurelie; Paroussos, Leonidas; Sano, Fuminori; Turton, Hal; Wilson, Charlie; Van Vuuren, Detlef

    2015-01-01T23:59:59.000Z

    Integrated assessments of how climate policy interacts with energy-economic systems can be performed by a variety of models with different functional structures. This article proposes a diagnostic scheme that can be applied to a wide range of integrated assessment models to classify differences among models based on their carbon price responses. Model diagnostics can uncover patterns and provide insights into why, under a given scenario, certain types of models behave in observed ways. Such insights are informative since model behavior can have a significant impact on projections of climate change mitigation costs and other policy-relevant information. The authors propose diagnostic indicators to characterize model responses to carbon price signals and test these in a diagnostic study with 11 global models. Indicators describe the magnitude of emission abatement and the associated costs relative to a harmonized baseline, the relative changes in carbon intensity and energy intensity and the extent of transformation in the energy system. This study shows a correlation among indicators suggesting that models can be classified into groups based on common patterns of behavior in response to carbon pricing. Such a classification can help to more easily explain variations among policy-relevant model results.

  14. Observations and simulations improve space weather models

    E-Print Network [OSTI]

    - 1 - Observations and simulations improve space weather models June 25, 2014 Los Alamos with fast-moving particles and a space weather system that varies in response to incoming energy computer simulations of the space weather that can affect vital technology, communication and navigation

  15. A multi-resolution method for climate system modeling: application of spherical centroidal Voronoi tessellations

    SciTech Connect (OSTI)

    Ringler, Todd [Los Alamos National Laboratory; Ju, Lili [University of South Carolina; Gunzburger, Max [Florida State University

    2008-01-01T23:59:59.000Z

    During the next decade and beyond, climate system models will be challenged to resolve scales and processes that are far beyond their current scope. Each climate system component has its prototypical example of an unresolved process that may strongly influence the global climate system, ranging from eddy activity within ocean models, to ice streams within ice sheet models, to surface hydrological processes within land system models, to cloud processes within atmosphere models. These new demands will almost certainly result in the develop of multiresolution schemes that are able, at least regionally, to faithfully simulate these fine-scale processes. Spherical centroidal Voronoi tessellations (SCVTs) offer one potential path toward the development of a robust, multiresolution climate system model components. SCVTs allow for the generation of high quality Voronoi diagrams and Delaunay triangulations through the use of an intuitive, user-defined density function. In each of the examples provided, this method results in high-quality meshes where the quality measures are guaranteed to improve as the number of nodes is increased. Real-world examples are developed for the Greenland ice sheet and the North Atlantic ocean. Idealized examples are developed for ocean–ice shelf interaction and for regional atmospheric modeling. In addition to defining, developing, and exhibiting SCVTs, we pair this mesh generation technique with a previously developed finite-volume method. Our numerical example is based on the nonlinear, shallow water equations spanning the entire surface of the sphere. This example is used to elucidate both the potential benefits of this multiresolution method and the challenges ahead.

  16. Aerosol, Cloud, and Climate: From Observation to Model

    ScienceCinema (OSTI)

    Jian Wang

    2010-09-01T23:59:59.000Z

    Scientists have long been investigating this phenomenon of "global warming," which is believed to be at least partly due to the increased carbon dioxide (CO2) concentration in the air from burning fossil fuels. Funded by DOE, teams of researchers from BNL and other national labs have been gathering data in the U.S. and internationally to build computer models of climate and weather to help in understanding general patterns, causes, and perhaps, solutions.

  17. Aerosol, Cloud, and Climate: From Observation to Model

    SciTech Connect (OSTI)

    Jian Wang

    2010-05-12T23:59:59.000Z

    Scientists have long been investigating this phenomenon of "global warming," which is believed to be at least partly due to the increased carbon dioxide (CO2) concentration in the air from burning fossil fuels. Funded by DOE, teams of researchers from BNL and other national labs have been gathering data in the U.S. and internationally to build computer models of climate and weather to help in understanding general patterns, causes, and perhaps, solutions.

  18. A modeling study on the climate impacts of black carbon aerosols

    E-Print Network [OSTI]

    Wang, Chien.

    The role of black carbon (BC) aerosols in climate change is important because of its strong capability in causing extinction of solar radiation. A three-dimensional interactive aerosol-climate model has been used to study ...

  19. Evaluating Energy Performance and Improvement Potential of China Office Buildings in the Hot Humid Climate Against U.S. Reference Buildings: Preprint

    SciTech Connect (OSTI)

    Herrman, L.; Deru, M.; Zhai, J.

    2010-08-01T23:59:59.000Z

    This study compares the building code standards for office buildings in hot humid climates of China and the USA. A benchmark office building model is developed for Guangzhou, China that meets China's minimum national and regional building codes with incorporation of common design and construction practices for the area. The Guangzhou office benchmark model is compared to the ASHRAE standard based US model for Houston, Texas which has similar climate conditions. The research further uses a building energy optimization tool to optimize the Chinese benchmark with existing US products to identify the primary areas for potential energy savings. The most significant energy-saving options are then presented as recommendations for potential improvements to current China building codes.

  20. Modeling Climate and Production-related Impacts on Ice-core Beryllium-10

    E-Print Network [OSTI]

    Modeling Climate and Production-related Impacts on Ice-core Beryllium-10 Christy Veeder Submitted Modeling Climate and Production-related Impacts on Ice-core Beryllium-10 Christy Veeder I use the Goddard Institute for Space Studies ModelE general circulation model to ex- amine the how beryllium-10, a cosmogenic

  1. World Climate Research Programme (WCRP) Coupled Model Intercomparison Project phase 3 (CMIP3): Multi-Model Dataset Archive at PCMDI (Program for Climate Model Diagnosis and Intercomparison)

    DOE Data Explorer [Office of Scientific and Technical Information (OSTI)]

    In response to a proposed activity of the WCRP's Working Group on Coupled Modelling (WGCM),PCMDI volunteered to collect model output contributed by leading modeling centers around the world. Climate model output from simulations of the past, present and future climate was collected by PCMDI mostly during the years 2005 and 2006, and this archived data constitutes phase 3 of the Coupled Model Intercomparison Project (CMIP3). In part, the WGCM organized this activity to enable those outside the major modeling centers to perform research of relevance to climate scientists preparing the Fourth Asssessment Report (AR4) of the Intergovernmental Panel on Climate Change (IPCC). The IPCC was established by the World Meteorological Organization and the United Nations Environmental Program to assess scientific information on climate change. The IPCC publishes reports that summarize the state of the science. This unprecedented collection of recent model output is officially known as the WCRP CMIP3 multi-model dataset. It is meant to serve IPCC's Working Group 1, which focuses on the physical climate system - atmosphere, land surface, ocean and sea ice - and the choice of variables archived at the PCMDI reflects this focus. A more comprehensive set of output for a given model may be available from the modeling center that produced it. As of November 2007, over 35 terabytes of data were in the archive and over 303 terabytes of data had been downloaded among the more than 1200 registered users. Over 250 journal articles, based at least in part on the dataset, have been published or have been accepted for peer-reviewed publication. Countries from which models have been gathered include Australia, Canada, China, France, Germany and Korea, Italy, Japan, Norway, Russia, Great Britain and the United States. Models, variables, and documentation are collected and stored. Check http://www-pcmdi.llnl.gov/ipcc/data_status_tables.htm to see at a glance the output that is available. (Description taken from http://www-pcmdi.llnl.gov/ipcc/about_ipcc.php)

  2. Evaluation of Continental Precipitation in 20th-Century Climate Simulations: The Utility of Multi-Model Statistics

    SciTech Connect (OSTI)

    Phillips, T J; Gleckler, P J

    2005-11-01T23:59:59.000Z

    At the request of the Intergovernmental Panel on Climate Change (IPCC), simulations of 20th-century climate have been performed recently with some 20 global coupled ocean-atmosphere models. In view of its central importance for biological and socio-economic systems, model-simulated continental precipitation is evaluated relative to three observational estimates at both global and regional scales. Many models are found to display systematic biases, deviating markedly from the observed spatial variability and amplitude/phase of the seasonal cycle. However, the point-wise ensemble mean of all the models usually shows better statistical agreement with the observations than does any single model. Deficiencies of current models that may be responsible for the simulated precipitation biases as well as possible reasons for the improved estimate afforded by the multi-model ensemble mean are discussed. Implications of these results for water-resource managers also are briefly addressed.

  3. Simulations of Present and Future Climates in the Western United States with Four Nested Regional Climate Models

    SciTech Connect (OSTI)

    Duffy, Phil; Arritt, R.; Coquard, J.; Gutowski, William; Han, J.; Iorio, J.; Kim, Jongil; Leung, Lai R.; Roads, J.; Zeledon, E.

    2006-03-15T23:59:59.000Z

    We analyze simulations of present and future climates in the western U.S. performed with four regional climate models (RCMs) nested within two global ocean-atmosphere climate models. Our primary goal is to assess the range of regional climate responses to increased greenhouse gases in available RCM simulations. The four RCMs used different geographical domains, different increased greenhouse gas scenarios for future-climate simulations, and (in some cases) different lateral boundary conditions. For simulations of the present climate, we compare RCM results to observations and to results of the GCM that provided lateral boundary conditions to the RCM. For future-climate (increased greenhouse gas) simulations, we compare RCM results to each other and to results of the driving GCMs. When results are spatially averaged over the western U.S., we find that the results of each RCM closely follow those of the driving GCM in the same region, in both present and future climates. This is true even though the study area is in some cases a small fraction of the RCM domain. Precipitation responses predicted by the RCMs are in many regions not statistically significant compared to interannual variability. Where the predicted precipitation responses are statistically significant, they are positive. The models agree that near-surface temperatures will increase, but do not agree on the spatial pattern of this increase. The four RCMs produce very different estimates of water content of snow in the present climate, and of the change in this water content in response to increased greenhouse gases.

  4. Crash testing hydrological models in contrasted climate conditions: An experiment on 216 Australian catchments

    E-Print Network [OSTI]

    Boyer, Edmond

    of these models (flow simulation, forecasting, design, reservoir management, climate change impact assessments of climate change on stream- flow has been an increasing concern in the past few years and has been the focus this transposability is a critical issue in the context of climate change impact studies where nonstationary condi

  5. A Finite Element Algorithm of a Nonlinear Diffusive Climate Energy Balance Model

    E-Print Network [OSTI]

    Díaz, Jesús Ildefonso

    A Finite Element Algorithm of a Nonlinear Diffusive Climate Energy Balance Model R. BERMEJO,1 J. This model belongs to the category of energy balance models introduced independently by the climatologists M climate. The energy balance model we are dealing with consists of a two-dimensional nonlinear parabolic

  6. A conceptual model to estimate cost effectiveness of the indoor environment improvements

    SciTech Connect (OSTI)

    Seppanen, Olli; Fisk, William J.

    2003-06-01T23:59:59.000Z

    Macroeconomic analyses indicate a high cost to society of a deteriorated indoor climate. The few example calculations performed to date indicate that measures taken to improve IEQ are highly cost-effective when health and productivity benefits are considered. We believe that cost-benefit analyses of building designs and operations should routinely incorporate health and productivity impacts. As an initial step, we developed a conceptual model that shows the links between improvements in IEQ and the financial gains from reductions in medical care and sick leave, improved work performance, lower employee turn over, and reduced maintenance due to fewer complaints.

  7. Property:Buildings/ModelClimateZone | Open Energy Information

    Open Energy Info (EERE)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page onYou are now leaving Energy.gov You are now leaving Energy.gov You are beingZealand Jump to: navigation,Pillar GroupInformationInformationYearConstruction1 JumpModelClimateZone

  8. Accelerated Climate Modeling For Energy Marcia Branstetter Katherine Evans

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative1 First Use of Energy for All Purposes (Fuel and Nonfuel), 2002; Level: National5Sales for4,645U.S. DOE Office511041cloth DocumentationProducts (VAP) VAP7-0973 1 Introduction In theACME - Accelerated Climate Modeling

  9. Improvement of snowpack simulations in a regional climate model

    E-Print Network [OSTI]

    Jin, J.

    2012-01-01T23:59:59.000Z

    that intensifies the solar radiation absorption on the landulate and predict the solar radiation budget at the sur-SW # the downward solar radiation, LWNET the net longwave

  10. Process Modeling for Process Improvement A Process Conformance Approach

    E-Print Network [OSTI]

    Process Modeling for Process Improvement - A Process Conformance Approach Sigurd Thunem September processes. In order to improve these processes, knowledge about them is necessary. To support process improve- ment the organization should collect process data, transform process data into knowledge

  11. Integrated science model for assessment of climate change

    SciTech Connect (OSTI)

    Jain, A.K.; Wuebbles, D.J. [Lawrence Livermore National Lab., CA (United States); Kheshgi, H.S. [Exxon Research and Engineering Co., Annandale, NJ (United States)

    1994-04-01T23:59:59.000Z

    Integrated assessment models are intended to represent processes that govern physical, ecological, economic and social systems. This report describes a scientific model relating emissions to global temperature and sea level. This model is intended to be one component of an integrated assessment model which is, of course, much more comprehensive. The model is able to reproduce past changes in CO{sub 2} concentration, global temperature, and sea level. The model is used to estimate the emissions rates required to lead to stabilization of CO{sub 2} at various levels. The model is also used to estimate global temperature rise, the rate of temperature change, and sea level rise driven by IPCC emissions scenarios. The emission of fossil fuel CO{sub 2} is modeled to have the largest long term effect on climate. Results do show the importance of expected changes of trace greenhouse gases other than CO{sub 2} in the near future. Because of the importance of these other trace gases, further work is recommended to more accurately estimate their effects.

  12. educating, engaging and empowering californians to improve our state's future California Climate

    E-Print Network [OSTI]

    Sadoulet, Elisabeth

    and Resources (BeaR) model, we find that if California improves energy efficiency by just 1 percent per year order #s­3­05 (schwarzenegger 2005) which calls for a 30 percent reduction below business- as on emissions that cause global warming, requires that the California air Resources Board (CaRB) put

  13. What is the importance of climate model bias when projecting the impacts of climate change on land surface processes?

    SciTech Connect (OSTI)

    Liu, M. L.; Rajagopalan, K.; Chung, S. H.; Jiang, X.; Harrison, J. H.; Nergui, T.; Guenther, Alex B.; Miller, C.; Reyes, J.; Tague, C. L.; Choate, J. S.; Salathe, E.; Stockle, Claudio O.; Adam, J. C.

    2014-05-16T23:59:59.000Z

    Regional climate change impact (CCI) studies have widely involved downscaling and bias-correcting (BC) Global Climate Model (GCM)-projected climate for driving land surface models. However, BC may cause uncertainties in projecting hydrologic and biogeochemical responses to future climate due to the impaired spatiotemporal covariance of climate variables and a breakdown of physical conservation principles. Here we quantify the impact of BC on simulated climate-driven changes in water variables(evapotranspiration, ET; runoff; snow water equivalent, SWE; and water demand for irrigation), crop yield, biogenic volatile organic compounds (BVOC), nitric oxide (NO) emissions, and dissolved inorganic nitrogen (DIN) export over the Pacific Northwest (PNW) Region. We also quantify the impacts on net primary production (NPP) over a small watershed in the region (HJ Andrews). Simulation results from the coupled ECHAM5/MPI-OM model with A1B emission scenario were firstly dynamically downscaled to 12 km resolutions with WRF model. Then a quantile mapping based statistical downscaling model was used to downscale them into 1/16th degree resolution daily climate data over historical and future periods. Two series climate data were generated according to the option of bias-correction (i.e. with bias-correction (BC) and without bias-correction, NBC). Impact models were then applied to estimate hydrologic and biogeochemical responses to both BC and NBC meteorological datasets. These im20 pact models include a macro-scale hydrologic model (VIC), a coupled cropping system model (VIC-CropSyst), an ecohydrologic model (RHESSys), a biogenic emissions model (MEGAN), and a nutrient export model (Global-NEWS). Results demonstrate that the BC and NBC climate data provide consistent estimates of the climate-driven changes in water fluxes (ET, runoff, and water demand), VOCs (isoprene and monoterpenes) and NO emissions, mean crop yield, and river DIN export over the PNW domain. However, significant differences rise from projected SWE, crop yield from dry lands, and HJ Andrews’s ET between BC and NBC data. Even though BC post-processing has no significant impacts on most of the studied variables when taking PNW as a whole, their effects have large spatial variations and some local areas are substantially influenced. In addition, there are months during which BC and NBC post-processing produces significant differences in projected changes, such as summer runoff. Factor-controlled simulations indicate that BC post-processing of precipitation and temperature both substantially contribute to these differences at region scales. We conclude that there are trade-offs between using BC climate data for offline CCI studies vs. direct modeled climate data. These trade-offs should be considered when designing integrated modeling frameworks for specific applications; e.g., BC may be more important when considering impacts on reservoir operations in mountainous watersheds than when investigating impacts on biogenic emissions and air quality (where VOCs are a primary indicator).

  14. Integrating chemistry into 3D climate models: Detailed kinetics in the troposphere and stratosphere of a global climate model

    SciTech Connect (OSTI)

    Kao, C.Y.J.; Elliott, S. [Los Alamos National Lab., NM (United States). Earth and Environmental Sciences Div.; Turco, R.P.; Zhao, X. [Univ. of California, Los Angeles, CA (United States)

    1997-11-01T23:59:59.000Z

    This is the final report of a three-year, Laboratory Directed Research and Development (LDRD) project at Los Alamos National Laboratory (LANL). The motivation for the project is to create the first complete, three-dimensional climate model that enfolds atmospheric photochemistry. The LANL chemical global climate model (GCM) not only distributes the trace greenhouse gases and modifies their concentrations within the detailed photochemical web, but also permits them to influence the radiation field and so force their own transport. Both atmospheric chemistry and fluid dynamics are nonlinear and zonally asymmetric phenomena. They can only be adequately modeled in three dimensions on the global grid. The kinetics-augmented GCM is the only program within the atmospheric community capable of investigating interaction involving chemistry and transport. The authors have conducted case studies of timely three-dimensional chemistry issues. Examples include ozone production from biomass burning plumes, kinetic feedbacks in zonally asymmetric transport phenomena with month- to year-long time scales, and volcano sulfate aerosols with respect to their potential effects on tropospheric ozone depletion.

  15. Advanced methods for uncertainty quantification in tail regions of climate model predictions.

    SciTech Connect (OSTI)

    Safta, Cosmin; Debusschere, Bert J.; Najm, Habib N.; Sargsyan, Khachik

    2010-09-01T23:59:59.000Z

    Conventional methods for uncertainty quantification are generally challenged in the 'tails' of probability distributions. This is specifically an issue for many climate observables since extensive sampling to obtain a reasonable accuracy in tail regions is especially costly in climate models. Moreover, the accuracy of spectral representations of uncertainty is weighted in favor of more probable ranges of the underlying basis variable, which, in conventional bases does not particularly target tail regions. Therefore, what is ideally desired is a methodology that requires only a limited number of full computational model evaluations while remaining accurate enough in the tail region. To develop such a methodology, we explore the use of surrogate models based on non-intrusive Polynomial Chaos expansions and Galerkin projection. We consider non-conventional and custom basis functions, orthogonal with respect to probability distributions that exhibit fat-tailed regions. We illustrate how the use of non-conventional basis functions, and surrogate model analysis, improves the accuracy of the spectral expansions in the tail regions. Finally, we also demonstrate these methodologies using precipitation data from CCSM simulations.

  16. ENERGY INVESTMENTS UNDER CLIMATE POLICY: A COMPARISON OF GLOBAL MODELS

    SciTech Connect (OSTI)

    McCollum, David; Nagai, Yu; Riahi, Keywan; Marangoni, Giacomo; Calvin, Katherine V.; Pietzcker, Robert; Van Vliet, Jasper; van der Zwaan, Bob

    2013-11-01T23:59:59.000Z

    The levels of investment needed to mobilize an energy system transformation and mitigate climate change are not known with certainty. This paper aims to inform the ongoing dialogue and in so doing to guide public policy and strategic corporate decision making. Within the framework of the LIMITS integrated assessment model comparison exercise, we analyze a multi-IAM ensemble of long-term energy and greenhouse gas emissions scenarios. Our study provides insight into several critical but uncertain areas related to the future investment environment, for example in terms of where capital expenditures may need to flow regionally, into which sectors they might be concentrated, and what policies could be helpful in spurring these financial resources. We find that stringent climate policies consistent with a 2°C climate change target would require a considerable upscaling of investments into low-carbon energy and energy efficiency, reaching approximately $45 trillion (range: $30–$75 trillion) cumulative between 2010 and 2050, or about $1.1 trillion annually. This represents an increase of some $30 trillion ($10–$55 trillion), or $0.8 trillion per year, beyond what investments might otherwise be in a reference scenario that assumes the continuation of present and planned emissions-reducing policies throughout the world. In other words, a substantial "clean-energy investment gap" of some $800 billion/yr exists — notably on the same order of magnitude as present-day subsidies for fossil energy and electricity worldwide ($523 billion). Unless the gap is filled rather quickly, the 2°C target could potentially become out of reach.

  17. Climate change projections using the IPSL-CM5 Earth System Model: from CMIP3 to CMIP5

    E-Print Network [OSTI]

    Codron, Francis

    Climate change projections using the IPSL-CM5 Earth System Model: from CMIP3 to CMIP5 J relevant to the climate system, it may be referred to as an Earth System Model. However, the IPSL-CM5 model climate and Earth System Models, both developed in France and contributing to the 5th coupled model

  18. Feedbacks in a simple prognostic tropical climate model

    SciTech Connect (OSTI)

    Sherwood, S.C. (Scripps Institution of Oceanography, La Jolla, CA (United States))

    1999-07-01T23:59:59.000Z

    A simple four-cell model of the tropical atmosphere in equilibrium with its boundaries is introduced, which can support a variable diabatic circulation and prognostic temperature and humidity profiles. The model is used to predict atmospheric perturbations away from the observed base state. Prognostic variables include radiation, surface fluxes, and dynamic transports, with temperature and water vapor levels determined by conservation constraints. The model includes a specially developed water vapor scheme that performs favorably compared with observations. The model is used to simulate the local and nonlocal sensitivity of the tropical maritime atmosphere to changes in surface temperature and other boundary conditions at very large horizontal scales. The main findings are as follows: (i) The sensitivity of boundary layer convergence to sea surface temperature (SST) variations depends on the behavior of convective heating over cooler regions and may be overestimated by heuristic models that ignore or oversimplify thermodynamic and radiative constraints; (ii) The maintenance of humidity equilibrium over weakly convective areas is modulated by local radiative feedback; (iii) Evaporation feedbacks on SST may be overestimated by heuristic arguments that do not carefully treat atmospheric water transport. An explanation for the constant-relative humidity behavior of general circulation models under climate changes is also offered based on the results.

  19. Improving efficiency of a vehicle HVAC system with comfort modeling...

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    efficiency of a vehicle HVAC system with comfort modeling, zonal design, and thermoelectric devices Improving efficiency of a vehicle HVAC system with comfort modeling, zonal...

  20. Climate sensitivity is investigated for 10 models that are participating in the IPCC Fourth Assessment Report.We consider the temporal evolution of climate sensitivity

    E-Print Network [OSTI]

    ABSTRACT Climate sensitivity is investigated for 10 models that are participating in the IPCC Fourth Assessment Report.We consider the temporal evolution of climate sensitivity and we analyze the transient climate sensitivity from fully coupled simulations with a 1% per year increase in CO2 in terms

  1. "Managing Department Climate Change"

    E-Print Network [OSTI]

    Sheridan, Jennifer

    "Managing Department Climate Change" #12;Presenters · Ronda Callister Professor, Department Department Climate? · Assesment is essential for determining strategies for initiating change · In a research climate · Each panelist will describe an intervention designed to improve department climate ­ Ronda

  2. TSINGHUA -MIT China Energy & Climate Project

    E-Print Network [OSTI]

    TSINGHUA - MIT China Energy & Climate Project Will economic restructuring in China reduce trade to: discover new interactions among natural and human climate system components; objectively assess future; and improve methods to model, monitor and verify greenhouse gas emissions and climatic impacts

  3. TSINGHUA -MIT China Energy & Climate Project

    E-Print Network [OSTI]

    TSINGHUA - MIT China Energy & Climate Project An Integrated Assessment of China's Wind Energy to: discover new interactions among natural and human climate system components; objectively assess future; and improve methods to model, monitor and verify greenhouse gas emissions and climatic impacts

  4. Ocean viscosity and climate M. Jochum,1

    E-Print Network [OSTI]

    Jochum, Markus

    Ocean viscosity and climate M. Jochum,1 G. Danabasoglu,1 M. Holland,1 Y.-O. Kwon,1 and W. G. Large1] The impacts of parameterized lateral ocean viscosity on climate are explored using three 120-year integrations of a fully coupled climate model. Reducing viscosity leads to a generally improved ocean circulation

  5. The mean climate of the Community Atmosphere Model (CAM4) in forced SST and fully coupled experiments

    SciTech Connect (OSTI)

    Neale, Richard; Richter, Jadwiga; Park, Sungsu; Lauritzen, P. H.; Vavrus, Steven J.; Rasch, Philip J.; Zhang, Minghua

    2013-07-15T23:59:59.000Z

    The Community Atmosphere Model, version 4 (CAM4) was released as the atmosphere component of the Community Climate System Model, version 4 (CCSM4) and is described. The finite volume dynamical core available in CAM3 is now the default due to its superior transport and conservation properties. Deep convection parameterization changes include a dilute plume calculation of convective available potential energy (CAPE) and the introduction of a formulation for Convective Momentum Transport (CMT). For the cloud fraction an additional calculation is performed following macrophysical state updates that provides improved thermodynamic condistancy. A freeze-drying modification is further made to the cloud fraction calculation in very dry environments, such as arctic Winter, where cloud fractionand cloud water estimates were often inconsistant in CAM3. In CAM4 the finite volume dynamical core leads to a degradation in the excessive trade-wind simulation, but with an accompanying reduction in zonal stresses at higher latitudes. Plume dilution leads to a moister deep tropics alleviating much of the mid-tropospheric dry biases and reduces the persistant precipitation biases over the Arabian peninsular and the southern Indian ocean during the Indian Monsoon. CMT reduces much of the excessive trade-wind biases in eastern ocean basins. The freeze drying modification alleviates much of the high latitude, winter-time excessive cloud bias and improves the associated surface cloud-related energy budget, but the updated cloud macrophysical calculation generally leads to reduced cloud fraction and cloud forcing away from high latitudes. Although there are marginal improvements in time-averaged, large-scale hydrology there are signficant improvements in regional climate features such as the generation of tropical and propagation of stationary waves from the Pacific into mid-latitudes and in the seasonal frequency of Northern Hemisphere blocking events. A 1? versus 2? horizontal resolution of the finite volume 24 dynamical core exhibits signficiant improvements in model climate. Improvements in the fully coupled mean climate between CAM3 and CAM4 are also much more signficant than in forced Sea Surface Temperature (SST) simulations. Furthermore, improvements in the transient characteristics ofthe model climate, documented elsewhere, are substantial.

  6. A Vast Machine Computer Models, Climate Data, and the Politics of Global Warming

    E-Print Network [OSTI]

    A Vast Machine Computer Models, Climate Data, and the Politics of Global Warming Paul N. Edwards models, climate data, and the politics of global warming / Paul N. Edwards. p. cm. Includes. Climatology--History. 3. Meteorology--History. 4. Climatology--Technological innovation. 5. Global temperature

  7. California Wintertime Precipitation in Regional and Global Climate Models

    SciTech Connect (OSTI)

    Caldwell, P M

    2009-04-27T23:59:59.000Z

    In this paper, wintertime precipitation from a variety of observational datasets, regional climate models (RCMs), and general circulation models (GCMs) is averaged over the state of California (CA) and compared. Several averaging methodologies are considered and all are found to give similar values when model grid spacing is less than 3{sup o}. This suggests that CA is a reasonable size for regional intercomparisons using modern GCMs. Results show that reanalysis-forced RCMs tend to significantly overpredict CA precipitation. This appears to be due mainly to overprediction of extreme events; RCM precipitation frequency is generally underpredicted. Overprediction is also reflected in wintertime precipitation variability, which tends to be too high for RCMs on both daily and interannual scales. Wintertime precipitation in most (but not all) GCMs is underestimated. This is in contrast to previous studies based on global blended gauge/satellite observations which are shown here to underestimate precipitation relative to higher-resolution gauge-only datasets. Several GCMs provide reasonable daily precipitation distributions, a trait which doesn't seem tied to model resolution. GCM daily and interannual variability is generally underpredicted.

  8. Climate Model Response from the Geoengineering Model Intercomparison Project (GeoMIP)

    SciTech Connect (OSTI)

    Kravitz, Benjamin S.; Caldeira, Ken; Boucher, Olivier; Robock, Alan; Rasch, Philip J.; Alterskjaer, Kari; Bou Karam, Diana; Cole, Jason N.; Curry, Charles L.; Haywood, J.; Irvine, Peter; Ji, Duoying; Jones, A.; Kristjansson, J. E.; Lunt, Daniel; Moore, John; Niemeier, Ulrike; Schmidt, Hauke; Schulz, M.; Singh, Balwinder; Tilmes, S.; Watanabe, Shingo; Yang, Shuting; Yoon, Jin-Ho

    2013-08-09T23:59:59.000Z

    Solar geoengineering—deliberate reduction in the amount of solar radiation retained by the Earth—has been proposed as a means of counteracting some of the climatic effects of anthropogenic greenhouse gas emissions. We present results from Experiment G1 of the Geoengineering Model Intercomparison Project, in which 12 climate models have simulated the climate response to an abrupt quadrupling of CO2 from preindustrial concentrations brought into radiative balance via a globally uniform reduction in insolation. Models show this reduction largely offsets global mean surface temperature increases due to quadrupled CO2 concentrations and prevents 97% of the Arctic sea ice loss that would otherwise occur under high CO2 levels but, compared to the preindustrial climate, leaves the tropics cooler (-0.3 K) and the poles warmer (+0.8 K). Annual mean precipitation minus evaporation anomalies for G1 are less than 0.2mmday-1 in magnitude over 92% of the globe, but some tropical regions receive less precipitation, in part due to increased moist static stability and suppression of convection. Global average net primary productivity increases by 120% in G1 over simulated preindustrial levels, primarily from CO2 fertilization, but also in part due to reduced plant heat stress compared to a high CO2 world with no geoengineering. All models show that uniform solar geoengineering in G1 cannot simultaneously return regional and global temperature and hydrologic cycle intensity to preindustrial levels.

  9. Post-2020 climate agreements in the major economies assessed in the light of global models

    SciTech Connect (OSTI)

    Tavoni, Massimo; Kriegler, Elmar; Riahi, Keywan; Van Vuuren, Detlef; Aboumahboub, Tino; Bowen, Alex; Calvin, Katherine V.; Campiglio, Emanuele; Kober, Tom; Jewell, Jessica; Luderer, Gunnar; Marangoni, Giacomo; McCollum, David; van Sluisveld, Mariesse; Zimmer, Anne; van der Zwaan, Bob

    2014-12-15T23:59:59.000Z

    Integrated assessment models can help in quantifying the implications of international climate agreements and regional climate action. This paper reviews scenario results from model intercomparison projects to explore different possible outcomes of post-2020 climate negotiations, recently announced pledges and their relation to the 2°C target. We provide key information for all the major economies, such as the year of emission peaking, regional carbon budgets and emissions allowances. We highlight the distributional consequences of climate policies, and discuss the role of carbon markets for financing clean energy investments, and achieving efficiency and equity.

  10. Development of Ensemble Neural Network Convection Parameterizations for Climate Models

    SciTech Connect (OSTI)

    Fox-Rabinovitz, M. S.; Krasnopolsky, V. M.

    2012-05-02T23:59:59.000Z

    The novel neural network (NN) approach has been formulated and used for development of a NN ensemble stochastic convection parametrization for climate models. This fast parametrization is built based on data from Cloud Resolving Model (CRM) simulations initialized with and forced by TOGA-COARE data. The SAM (System for Atmospheric Modeling), developed by D. Randall, M. Khairoutdinov, and their collaborators, has been used for CRM simulations. The observational data are also used for validation of model simulations. The SAM-simulated data have been averaged and projected onto the GCM space of atmospheric states to implicitly define a stochastic convection parametrization. This parametrization is emulated using an ensemble of NNs. An ensemble of NNs with different NN parameters has been trained and tested. The inherent uncertainty of the stochastic convection parametrization derived in such a way is estimated. Due to these inherent uncertainties, NN ensemble is used to constitute a stochastic NN convection parametrization. The developed NN convection parametrization have been validated in a diagnostic CAM (CAM-NN) run vs. the control CAM run. Actually, CAM inputs have been used, at every time step of the control/original CAM integration, for parallel calculations of the NN convection parametrization (CAM-NN) to produce its outputs as a diagnostic byproduct. Total precipitation (P) and cloudiness (CLD) time series, diurnal cycles, and P and CLD distributions for the large Tropical Pacific Ocean for the parallel CAM-NN and CAM runs show similarity and consistency with the NCEP reanalysis. The P and CLD distributions for the tropical area for the parallel runs have been analyzed first for the TOGA-COARE boreal winter season (November 1992 through February 1993) and then for the winter seasons of the follow-up parallel decadal simulations. The obtained results are encouraging and practically meaningful. They show the validity of the NN approach. This constitutes an important practical conclusion of the study: the obtained results on NN ensembles as a stochastic physics parametrization show a realistic possibility of development of NN convection parametrization for climate (and NWP) models based on learning cloud physics from CRM/SAM simulated data.

  11. An examination of urban heat island characteristics in a global climate model

    E-Print Network [OSTI]

    Oleson, Keith W.; Bonan, Gordon B.; Feddema, Johannes J.; Jackson, Trisha L.

    2010-07-27T23:59:59.000Z

    A parameterization for urban surfaces has been incorporated into the Community Land Model as part of the Community Climate System Model. The parameterization allows global simulation of the urban environment, in particular the temperature of cities...

  12. Intercomparison of the Cloud Water Phase among Global Climate Models

    SciTech Connect (OSTI)

    Komurcu, Muge; Storelvmo, Trude; Tan, Ivy; Lohmann, U.; Yun, Yuxing; Penner, Joyce E.; Wang, Yong; Liu, Xiaohong; Takemura, T.

    2014-03-27T23:59:59.000Z

    Mixed-phase clouds (clouds that consist of both cloud droplets and ice crystals) are frequently present in the Earth’s atmosphere and influence the Earth’s energy budget through their radiative properties, which are highly dependent on the cloud water phase. In this study, the phase partitioning of cloud water is compared among six global climate models (GCMs) and with Cloud and Aerosol Lidar with Orthogonal Polarization retrievals. It is found that the GCMs predict vastly different distributions of cloud phase for a given temperature, and none of them are capable of reproducing the spatial distribution or magnitude of the observed phase partitioning. While some GCMs produced liquid water paths comparable to satellite observations, they all failed to preserve sufficient liquid water at mixed-phase cloud temperatures. Our results suggest that validating GCMs using only the vertically integrated water contents could lead to amplified differences in cloud radiative feedback. The sensitivity of the simulated cloud phase in GCMs to the choice of heterogeneous ice nucleation parameterization is also investigated. The response to a change in ice nucleation is quite different for each GCM, and the implementation of the same ice nucleation parameterization in all models does not reduce the spread in simulated phase among GCMs. The results suggest that processes subsequent to ice nucleation are at least as important in determining phase and should be the focus of future studies aimed at understanding and reducing differences among the models.

  13. Moisture Flux Convergence in Regional and Global Climate Models: Implications for Droughts in the Southwestern United States Under Climate Change

    SciTech Connect (OSTI)

    Gao, Yanhong; Leung, Lai-Yung R.; Salathe, E.; Dominguez, Francina; Nijssen, Bart; Lettenmaier, D. P.

    2012-05-10T23:59:59.000Z

    The water cycle of the southwestern United States (SW) is dominated by winter storms that maintain a positive annual net precipitation. Analysis of the control and future climate from four pairs of regional and global climate models (RCMs and GCMs) shows that the RCMs simulate a higher fraction of transient eddy moisture fluxes because the hydrodynamic instabilities associated with flow over complex terrain are better resolved. Under global warming, this enables the RCMs to capture the response of transient eddies to increased atmospheric stability that allows more moisture to converge on the windward side of the mountains by blocking. As a result, RCMs simulate enhanced transient eddy moisture convergence in the SW compared to GCMs, although both robustly simulate drying due to enhanced moisture divergence by the divergent mean flow in a warmer climate. This enhanced convergence leads to reduced susceptibility to hydrological change in the RCMs compared to GCMs.

  14. Toward an Improved Model of Asphalt Binder Oxidation in Pavements

    E-Print Network [OSTI]

    Prapaitrakul, Nikornpon

    2011-02-22T23:59:59.000Z

    and oxygen transport model, coupled with binder reaction kinetics, provides the basis for such calculations. A one-dimensional thermal transport model, coupled with site-specific model parameters and recent improvements in the availability of required input...

  15. Progress Report 2008: A Scalable and Extensible Earth System Model for Climate Change Science

    SciTech Connect (OSTI)

    Drake, John B [ORNL; Worley, Patrick H [ORNL; Hoffman, Forrest M [ORNL; Jones, Phil [Los Alamos National Laboratory (LANL)

    2009-01-01T23:59:59.000Z

    This project employs multi-disciplinary teams to accelerate development of the Community Climate System Model (CCSM), based at the National Center for Atmospheric Research (NCAR). A consortium of eight Department of Energy (DOE) National Laboratories collaborate with NCAR and the NASA Global Modeling and Assimilation Office (GMAO). The laboratories are Argonne (ANL), Brookhaven (BNL) Los Alamos (LANL), Lawrence Berkeley (LBNL), Lawrence Livermore (LLNL), Oak Ridge (ORNL), Pacific Northwest (PNNL) and Sandia (SNL). The work plan focuses on scalablity for petascale computation and extensibility to a more comprehensive earth system model. Our stated goal is to support the DOE mission in climate change research by helping ... To determine the range of possible climate changes over the 21st century and beyond through simulations using a more accurate climate system model that includes the full range of human and natural climate feedbacks with increased realism and spatial resolution.

  16. atmospheric climate model: Topics by E-print Network

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Curry & Webster Atmospheric Thermodynamics Ch1 Composition Ch2 Laws Ch3 Transfers Ch12 Energy Russell, Lynn 10 Climate Sciences: Atmospheric Thermodynamics Environmental...

  17. Technical Note: On the Use of Nudging for Aerosol-Climate Model Intercomparison Studies

    SciTech Connect (OSTI)

    Zhang, Kai; Wan, Hui; Liu, Xiaohong; Ghan, Steven J.; Kooperman, G. J.; Ma, Po-Lun; Rasch, Philip J.; Neubauer, David; Lohmann, U.

    2014-08-26T23:59:59.000Z

    Nudging is an assimilation technique widely used in the development and evaluation of climate models. Con- straining the simulated wind and temperature fields using global weather reanalysis facilitates more straightforward comparison between simulation and observation, and reduces uncertainties associated with natural variabilities of the large-scale circulation. On the other hand, the artificial forcing introduced by nudging can be strong enough to change the basic characteristics of the model climate. In the paper we show that for the Community Atmosphere Model version 5, due to the systematic temperature bias in the standard model and the relatively strong sensitivity of homogeneous ice nucleation to aerosol concentration, nudging towards reanalysis results in substantial reductions in the ice cloud amount and the impact of anthropogenic aerosols on longwave cloud forcing. In order to reduce discrepancies between the nudged and unconstrained simulations and meanwhile take the advantages of nudging, two alternative experimentation methods are evaluated. The first one constrains only the horizontal winds. The second method nudges both winds and temperature, but replaces the long-term climatology of the reanalysis by that of the model. Results show that both methods lead to substantially improved agreement with the free-running model in terms of the top-of-atmosphere radiation budget and cloud ice amount. The wind-only nudging is more convenient to apply, and provides higher correlations of the wind fields, geopotential height and specific humidity between simulation and reanalysis. This suggests that nudging the horizontal winds but not temperature is a good strategy, especially for studies that involve both warm and cold clouds.

  18. The Impact of IBM Cell Technology on the Programming Paradigm in the Context of Computer Systems for Climate and Weather Models

    E-Print Network [OSTI]

    Zhou, Shujia

    2009-01-01T23:59:59.000Z

    Acceleration of Numerical Weather Prediction,” ProceedingsComputer Systems for Climate and Weather Models Shujia Zhouprocesses in climate and weather models demands a continual

  19. Analysis of improved fenestration for code-compliant residential buildings in hot and humid climates 

    E-Print Network [OSTI]

    Mukhopadhyay, Jaya

    2006-10-30T23:59:59.000Z

    -efficient fenestration products for residential buildings in both heating and cooling climates. Prominent among these options is the emergence of low-E coatings which are usually ultra-thin, heat-reflecting, metalized optical coatings applied to one or more surfaces... coated glazing immensely alters glazing properties. Low-E coatings applied to the outer surface of the inner pane of double pane fenestration help to retain heat trapped within the envelope, and hence is preferred for heating dominated climates (Johnson...

  20. IMPROVING CATASTROPHE MODELING FOR BUSINESS INTERRUPTION INSURANCE NEEDS

    E-Print Network [OSTI]

    Wang, Hai

    IMPROVING CATASTROPHE MODELING FOR BUSINESS INTERRUPTION INSURANCE NEEDS by Adam Rose Price School, Surrey, UK KT21 2BT May 10, 2012 #12;1 IMPROVING CATASTROPHE MODELING FOR BUSINESS INTERRUPTION INSURANCE modeling of business interruption (BI) is still in a relative state of infancy. One reason

  1. PAGES 111–112 Climate and Earth system models are the

    E-Print Network [OSTI]

    unknown authors

    only tools used to make predictions of future climate change. Such predictions are subject to considerable uncertainties, and understanding these uncertainties has clear and important policy implications. This Forum highlights the concepts of reductionism and emergence, and past climate variability, to illuminate some of the uncertainties faced by those wishing to model the future evolution of global climate. General circulation models (GCMs) of the atmosphere-ocean system are scientists’ principal tools for providing information about future climate. GCMs consequently have considerable influence on climate change–related policy questions. Over the past decade, there have been significant attempts, mainly by statisticians and mathematicians, to explore the uncertainties in model simulations of possible futures, accompanied by growing debate about the interpretation of these simulations as aids in societal decisions. In this Forum, we discuss atmosphere-ocean GCMs in the context of reductionist and emergent approaches to scientific study.

  2. Using Dempster-Shafer Theory to model uncertainty in climate change and environmental impact

    E-Print Network [OSTI]

    Boyer, Edmond

    Using Dempster-Shafer Theory to model uncertainty in climate change and environmental impact]. The design wave overtopping in a context of changing climate cannot be deterministically predicted due defense structure due to (1) uncertain elevation of the mean water level and (2) uncertain level of storm

  3. Collaborative Research: Towards Advanced Understanding and Predictive Capability of Climate Change in the Arctic using a High-Resolution Regional Arctic Climate System Model

    SciTech Connect (OSTI)

    Lettenmaier, Dennis P

    2013-04-08T23:59:59.000Z

    Primary activities are reported in these areas: climate system component studies via one-way coupling experiments; development of the Regional Arctic Climate System Model (RACM); and physical feedback studies focusing on changes in Arctic sea ice using the fully coupled model.

  4. Data Collection for Improved Cold Temperature Thermal Modeling...

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    More Documents & Publications Data Collection for Improved Cold Temperature Thermal Modeling Energy Management Strategies for Fast Battery Temperature Rise and Engine...

  5. Improved computer models support genetics research

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Simple computer models unravel genetic stress reactions in cells Simple computer models unravel genetic stress reactions in cells Integrated biological and computational methods...

  6. CLIMATE SCIENCE The Community Climate System Model results from a multi-agency collaboration

    E-Print Network [OSTI]

    Long, Nicholas

    . Could global warming be responsible for the July 2006 heat waves in Europe and the United States? Should- ter(NCDC),whicharchivesallweatherdataforthe nation, reports that global surface temperatures have, the DOEisdedicatedtoadvancingclimateresearchin order to elucidate the causes of climate change, includingtheroleofcarbonloadingfromfossilfuel use

  7. Predicting Coupled Ocean-Atmosphere Modes with a Climate Modeling Hierarchy -- Final Report

    SciTech Connect (OSTI)

    Michael Ghil, UCLA; Andrew W. Robertson, IRI, Columbia Univ.; Sergey Kravtsov, U. of Wisconsin, Milwaukee; Padhraic Smyth, UC Irvine

    2006-08-04T23:59:59.000Z

    The goal of the project was to determine midlatitude climate predictability associated with tropical-extratropical interactions on interannual-to-interdecadal time scales. Our strategy was to develop and test a hierarchy of climate models, bringing together large GCM-based climate models with simple fluid-dynamical coupled ocean-ice-atmosphere models, through the use of advanced probabilistic network (PN) models. PN models were used to develop a new diagnostic methodology for analyzing coupled ocean-atmosphere interactions in large climate simulations made with the NCAR Parallel Climate Model (PCM), and to make these tools user-friendly and available to other researchers. We focused on interactions between the tropics and extratropics through atmospheric teleconnections (the Hadley cell, Rossby waves and nonlinear circulation regimes) over both the North Atlantic and North Pacific, and the ocean’s thermohaline circulation (THC) in the Atlantic. We tested the hypothesis that variations in the strength of the THC alter sea surface temperatures in the tropical Atlantic, and that the latter influence the atmosphere in high latitudes through an atmospheric teleconnection, feeding back onto the THC. The PN model framework was used to mediate between the understanding gained with simplified primitive equations models and multi-century simulations made with the PCM. The project team is interdisciplinary and built on an existing synergy between atmospheric and ocean scientists at UCLA, computer scientists at UCI, and climate researchers at the IRI.

  8. Optimization models for improving periodic maintenance schedules by utilizing opportunities

    E-Print Network [OSTI]

    Patriksson, Michael

    to this as preventive maintenance activities at an oppor- tunity. The original opportunistic replacement problemOptimization models for improving periodic maintenance schedules by utilizing opportunities Torgny of Technology Abstract We present mathematical models for finding optimal opportunistic maintenance schedules

  9. High-Resolution Modeling to Assess Tropical Cyclone Activity in Future Climate Regimes

    SciTech Connect (OSTI)

    Lackmann, Gary

    2013-06-10T23:59:59.000Z

    Applied research is proposed with the following objectives: (i) to determine the most likely level of tropical cyclone intensity and frequency in future climate regimes, (ii) to provide a quantitative measure of uncertainty in these predictions, and (iii) to improve understanding of the linkage between tropical cyclones and the planetary-scale circulation. Current mesoscale weather forecasting models, such as the Weather Research and Forecasting (WRF) model, are capable of simulating the full intensity of tropical cyclones (TC) with realistic structures. However, in order to accurately represent both the primary and secondary circulations in these systems, model simulations must be configured with sufficient resolution to explicitly represent convection (omitting the convective parameterization scheme). Most previous numerical studies of TC activity at seasonal and longer time scales have not utilized such explicit convection (EC) model runs. Here, we propose to employ the moving nest capability of WRF to optimally represent TC activity on a seasonal scale using a downscaling approach. The statistical results of a suite of these high-resolution TC simulations will yield a realistic representation of TC intensity on a seasonal basis, while at the same time allowing analysis of the feedback that TCs exert on the larger-scale climate system. Experiments will be driven with analyzed lateral boundary conditions for several recent Atlantic seasons, spanning a range of activity levels and TC track patterns. Results of the ensemble of WRF simulations will then be compared to analyzed TC data in order to determine the extent to which this modeling setup can reproduce recent levels of TC activity. Next, the boundary conditions (sea-surface temperature, tropopause height, and thermal/moisture profiles) from the recent seasons will be altered in a manner consistent with various future GCM/RCM scenarios, but that preserves the large-scale shear and incipient disturbance activity. This will allow (i) a direct comparison of future TC activity that could be expected for an active or inactive season in an altered climate regime, and (ii) a measure of the level of uncertainty and variability in TC activity resulting from different carbon emission scenarios.

  10. On the Single-Zone Modeling for Optimal Climate Control of a Real-Sized Livestock Stable System

    E-Print Network [OSTI]

    Yang, Zhenyu

    climate control systems. A typical modern stable system is usually equipped with a hybrid ventilation [3On the Single-Zone Modeling for Optimal Climate Control of a Real-Sized Livestock Stable System and implementation of a model-based optimal indoor climate control for a real-sized livestock stable system

  11. Variation in Estimated Ozone-Related Health Impacts of Climate Change due to Modeling Choices and Assumptions

    SciTech Connect (OSTI)

    Post, Ellen S.; Grambsch, A.; Weaver, C. P.; Morefield, Philip; Huang, Jin; Leung, Lai-Yung R.; Nolte, Christopher G.; Adams, P. J.; Liang, Xin-Zhong; Zhu, J.; Mahoney, Hardee

    2012-11-01T23:59:59.000Z

    Future climate change may cause air quality degradation via climate-induced changes in meteorology, atmospheric chemistry, and emissions into the air. Few studies have explicitly modeled the potential relationships between climate change, air quality, and human health, and fewer still have investigated the sensitivity of estimates to the underlying modeling choices.

  12. Modeling Climate Feedbacks to Energy Demand: The Case of China

    E-Print Network [OSTI]

    Asadoorian, Malcolm O.

    This paper is an empirical investigation of the effects of climate on the use of electricity by consumers and producers in urban and rural areas within China. It takes advantage of an unusual combination of temporal and ...

  13. Modeled climate change effects on distributions of Canadian butterfly species

    E-Print Network [OSTI]

    Peterson, A. Townsend; Martí nez-Meyer, Enrique; Gonzá lez-Salazar, Constantino; Hall, Peter W.

    2004-07-30T23:59:59.000Z

    Abstract: Climate change effects on biodiversity are being documented now frequently in the form of changes in phenology and distributional shifts. However, the form that these effects will take over a longer timespan is ...

  14. Valuing Climate Impacts in Integrated Assessment Models: The MIT IGSM

    E-Print Network [OSTI]

    Reilly, John

    2012-05-22T23:59:59.000Z

    We discuss a strategy for investigating the impacts of climate change on Earth’s physical, biological and human resources and links to their socio-economic consequences. The features of the integrated global system framework ...

  15. A SIMULATION MODEL FOR CANADA-US CLIMATE POLICY ANALYSIS

    E-Print Network [OSTI]

    gas emissions; carbon tax; energy consumption; energy supply; energy trade Subject Terms: Climatic forecasts energy demand and emissions by simulating the consumption of energy services and the choice, Washington 99352 USA ___________________________________________ Dr. John Nyboer Adjunct Professor School

  16. Climate Systems and Climate Change Is Climate Change Real?

    E-Print Network [OSTI]

    Pan, Feifei

    Chapter 10 Climate Systems and Climate Change #12;Is Climate Change Real? 1980 1898 2005 2003 #12;Arctic Sea Ice Changes #12;Observed Global Surface Air Temperature #12;! Current climate: weather station data, remote sensing data, numerical modeling using General Circulation Models (GCM) ! Past climate

  17. Evaluation of short-term climate change prediction in multi-model CMIP5 decadal hindcasts

    E-Print Network [OSTI]

    Webster, Peter J.

    events such as trop- ical cyclone activity. On decadal timescales, some aspects of internal climate skill of individual models have been analyzed separately for multi-year prediction horizons over

  18. Modeling land surface processes of the midwestern United States : predicting soil moisture under a warmer climate

    E-Print Network [OSTI]

    Winter, Jonathan (Jonathan Mark)

    2010-01-01T23:59:59.000Z

    This dissertation seeks to quantify the response of soil moisture to climate change in the midwestern United States. To assess this response, a dynamic global vegetation model, Integrated Biosphere Simulator, was coupled ...

  19. Improvement of Offshore Wind Resource Modeling in the Mid-

    E-Print Network [OSTI]

    Firestone, Jeremy

    Improvement of Offshore Wind Resource Modeling in the Mid- Atlantic Bight Wind Energy Symposium Sienkiewicz , Chris Hughes 26 February 2013 #12;Improving Atmospheric Models for Offshore Wind Resource Interaction Tower ­ 23 m NOAA Buzzard's Bay Tower ­ 25 m Cape Wind Tower (60 m from 2003-2011; just platform

  20. Modeling Climate-Water Impacts on Electricity Sector Capacity Expansion: Preprint

    SciTech Connect (OSTI)

    Cohen, S. M.; Macknick, J.; Averyt, K.; Meldrum, J.

    2014-05-01T23:59:59.000Z

    Climate change has the potential to exacerbate water availability concerns for thermal power plant cooling, which is responsible for 41% of U.S. water withdrawals. This analysis describes an initial link between climate, water, and electricity systems using the National Renewable Energy Laboratory (NREL) Regional Energy Deployment System (ReEDS) electricity system capacity expansion model. Average surface water projections from Coupled Model Intercomparison Project 3 (CMIP3) data are applied to surface water rights available to new generating capacity in ReEDS, and electric sector growth is compared with and without climate-influenced water rights. The mean climate projection has only a small impact on national or regional capacity growth and water use because most regions have sufficient unappropriated or previously retired water rights to offset climate impacts. Climate impacts are notable in southwestern states that purchase fewer water rights and obtain a greater share from wastewater and other higher-cost water resources. The electric sector climate impacts demonstrated herein establish a methodology to be later exercised with more extreme climate scenarios and a more rigorous representation of legal and physical water availability.

  1. Experiments with a time-dependent, zonally averaged, seasonal, enery balance climatic model

    E-Print Network [OSTI]

    Thompson, Starley Lee

    1977-01-01T23:59:59.000Z

    EXPERIMENTS WITH A TI&E-DEPENDENT, ZONALLY AVERAGED, SEASONAL, ENERGY BALANCE CLIMATIC MODEL A Thesis by STARLEY LEE THOMPSON Submitted to the Graduate College of Texas ASM University in partial fulfillment of the requirement for the decree... of MASTER OF SCIENCE December 1977 Major Subject: Meteorology EXPERIMENTS WITH A TIME DEPENDENT~ ZONALLY AVERAGED~ SEASONAL, ENERGY BALANCE CLIMATIC MODEL A Thesis by STARLEY LEE THOMPSON Approved as to style and content by: (Chairman of Committee...

  2. Experiments with a time-dependent, zonally averaged, seasonal, enery balance climatic model 

    E-Print Network [OSTI]

    Thompson, Starley Lee

    1977-01-01T23:59:59.000Z

    EXPERIMENTS WITH A TI&E-DEPENDENT, ZONALLY AVERAGED, SEASONAL, ENERGY BALANCE CLIMATIC MODEL A Thesis by STARLEY LEE THOMPSON Submitted to the Graduate College of Texas ASM University in partial fulfillment of the requirement for the decree... of MASTER OF SCIENCE December 1977 Major Subject: Meteorology EXPERIMENTS WITH A TIME DEPENDENT~ ZONALLY AVERAGED~ SEASONAL, ENERGY BALANCE CLIMATIC MODEL A Thesis by STARLEY LEE THOMPSON Approved as to style and content by: (Chairman of Committee...

  3. Transformer Thermal Modeling: Improving Reliability Using Data Quality Control

    E-Print Network [OSTI]

    1 Transformer Thermal Modeling: Improving Reliability Using Data Quality Control Daniel J. Tylavsky--Eventually all large transformers will be dynamically loaded using models updated regularly from field measured data. Models obtained from measured data give more accurate results than models based on transformer

  4. Improved computer models support genetics research

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Simple computer models unravel genetic stress reactions in cells Integrated biological and computational methods provide insight into why genes are activated. February 8, 2013 When...

  5. The Role of Asia in Mitigating Climate Change: Results from the Asia Modeling Exercise

    SciTech Connect (OSTI)

    Calvin, Katherine V.; Clarke, Leon E.; Krey, Volker; Blanford, Geoffrey J.; Jiang, Kejun; Kainuma, M.; Kriegler, Elmar; Luderer, Gunnar; Shukla, Priyadarshi R.

    2012-12-01T23:59:59.000Z

    In 2010, Asia accounted for 60% of global population, 39% of Gross World Product, 44% of global energy consumption and nearly half of the world’s energy system CO2 emissions. Thus, Asia is an important region to consider in any discussion of climate change or climate change mitigation. This paper explores the role of Asia in mitigating climate change, by comparing the results of 23 energy-economy and integrated assessment models. We focus our analysis on seven key areas: base year data, future energy use and emissions absent climate policy, the effect of urban and rural development on future energy use and emissions, the role of technology in emissions mitigation, regional emissions mitigation, and national climate policies

  6. Modeling the response of plants and ecosystems to elevated CO sub 2 and climate change

    SciTech Connect (OSTI)

    Reynolds, J.F.; Hilbert, D.W.; Chen, Jia-lin; Harley, P.C.; Kemp, P.R.; Leadley, P.W.

    1992-03-01T23:59:59.000Z

    While the exact effects of elevated CO{sub 2} on global climate are unknown, there is a growing consensus among climate modelers that global temperature and precipitation will increase, but that these changes will be non-uniform over the Earth's surface. In addition to these potential climatic changes, CO{sub 2} also directly affects plants via photosynthesis, respiration, and stomatal closure. Global climate change, in concert with these direct effects of CO{sub 2} on plants, could have a significant impact on both natural and agricultural ecosystems. Society's ability to prepare for, and respond to, such changes depends largely on the ability of climate and ecosystem researchers to provide predictions of regional level ecosystem responses with sufficient confidence and adequate lead time.

  7. Modeling the response of plants and ecosystems to elevated CO{sub 2} and climate change

    SciTech Connect (OSTI)

    Reynolds, J.F.; Hilbert, D.W.; Chen, Jia-lin; Harley, P.C.; Kemp, P.R.; Leadley, P.W.

    1992-03-01T23:59:59.000Z

    While the exact effects of elevated CO{sub 2} on global climate are unknown, there is a growing consensus among climate modelers that global temperature and precipitation will increase, but that these changes will be non-uniform over the Earth`s surface. In addition to these potential climatic changes, CO{sub 2} also directly affects plants via photosynthesis, respiration, and stomatal closure. Global climate change, in concert with these direct effects of CO{sub 2} on plants, could have a significant impact on both natural and agricultural ecosystems. Society`s ability to prepare for, and respond to, such changes depends largely on the ability of climate and ecosystem researchers to provide predictions of regional level ecosystem responses with sufficient confidence and adequate lead time.

  8. Sandia National Laboratories: Modeling

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    from improved climate models to performance models for underground waste storage to 3D printing and digital rock physics. Marianne Walck (Director ... Sandia Team Attends World...

  9. Improved diagnostic model for estimating wind energy

    SciTech Connect (OSTI)

    Endlich, R.M.; Lee, J.D.

    1983-03-01T23:59:59.000Z

    Because wind data are available only at scattered locations, a quantitative method is needed to estimate the wind resource at specific sites where wind energy generation may be economically feasible. This report describes a computer model that makes such estimates. The model uses standard weather reports and terrain heights in deriving wind estimates; the method of computation has been changed from what has been used previously. The performance of the current model is compared with that of the earlier version at three sites; estimates of wind energy at four new sites are also presented.

  10. An improved model for flashing flow in short tubes

    SciTech Connect (OSTI)

    Tilton, J.D.; Kornhauser, A.A. [Virginia Polytechnic Inst. and State Univ., Blacksburg, VA (United States). Dept. of Mechanical Engineering

    1996-12-31T23:59:59.000Z

    Short tube restrictors are commonly used as expansion devices in refrigeration and heat pumping systems. Flashing flow through short tubes is choked, i.e. independent of downstream conditions. Flow rate is typically predicted by empirically correcting the flow rate of compressed liquid from upstream pressure to saturation pressure at upstream temperature. The empirical correction factors depend on pressure and temperature, on short tube geometry, and on the refrigerant used. This work extends and improves a model of short tube flow based on the physics of the observed flow phenomena. Short tube flow is believed to consist of a core of superheated liquid surrounded by an annulus of vapor. Evaporation is driven by heat transfer form the core to tine interface, and the flow is choked by the evaporated vapor. Flow rate is modeled by calculating the heat transfer rate, the evaporation rate, and the choking effect of the vapor. The model attempts to improve on previous work by improving the accuracy with which thermodynamic properties are approximated, by improving the heat transfer model, and by including the effects of frictional heating of the liquid. In comparisons with experimental data it is found that the improved thermodynamic modeling increases accuracy, but the change to the heat transfer model reduces accuracy. For the data examined the effects of the frictional heating are small. The heat transfer model is based on an existing analytic solution with a mixing-length turbulence model. It appears that this model must be further improved, perhaps through empirical modification.

  11. Simulation Models for Improved Water Heating Systems

    E-Print Network [OSTI]

    Lutz, Jim

    2014-01-01T23:59:59.000Z

    and Simulation of a Smart Water Heater. ” In Workshop inFreezers, Furnaces, Water Heaters, Room and Central AirNovember. ADL. 1982b. Water Heater Computer Model User’s

  12. An improved model for multiple effect distillation

    E-Print Network [OSTI]

    Mistry, Karan H.

    Increasing global demand for fresh water is driving research and development of advanced desalination technologies. As a result, a detailed model of multiple effect distillation (MED) is developed that is flexible, simple ...

  13. Climate-Soil-Vegetation Control on Groundwater Table Dynamics and its Feedbacks in a Climate Model

    SciTech Connect (OSTI)

    Leung, Lai-Yung R.; Huang, Maoyi; Qian, Yun; Liang, Xu

    2010-01-29T23:59:59.000Z

    Among the three dynamically linked branches of the water cycle, including atmospheric, surface, and subsurface water, groundwater is the largest reservoir and an active component of the hydrologic system. Because of the inherent slow response time, groundwater may be particularly relevant for long time-scale processes such as multi-years or decadal droughts. This study uses regional climate simulations with and without surface water – groundwater interactions for the conterminous U.S. to assess the influence of climate, soil, and vegetation on groundwater table dynamics, and its potential feedbacks to regional climate. Analysis shows that precipitation has a dominant influence on the spatial and temporal variations of groundwater table depth (GWT). The simulated GWT is found to decrease sharply with increasing precipitation. Our simulation also shows some distinct spatial variations that are related to soil porosity and hydraulic conductivity. Vegetation properties such as minimum stomatal resistance, and root depth and fraction are also found to play an important role in controlling the groundwater table. Comparing two simulations with and without groundwater table dynamics, we find that groundwater table dynamics mainly influences the partitioning of soil water between the surface (0 – 0.5 m) and subsurface (0.5 – 5 m) rather than total soil moisture. In most areas, groundwater table dynamics increases surface soil moisture at the expense of the subsurface, except in regions with very shallow groundwater table. The change in soil water partitioning between the surface and subsurface is found to strongly correlate with the partitioning of surface sensible and latent heat fluxes. The evaporative fraction (EF) is generally higher during summer when groundwater table dynamics is included. This is accompanied by increased cloudiness, reduced diurnal temperature range, cooler surface temperature, and increased cloud top height. Although both convective and non-convective precipitation are enhanced, the higher EF changes the partitioning to favor more non-convective precipitation, but this result could be sensitive to the convective parameterization used. Compared to simulations without groundwater table dynamics, the dry bias in the summer precipitation is slightly reduced over the central and eastern U.S. Groundwater table dynamics can provide important feedbacks to atmospheric processes, and these feedbacks are stronger in regions with deeper groundwater table, because the interactions between surface and subsurface are weak when the groundwater table is deep. This increases the sensitivity of surface soil moisture to precipitation anomalies, and therefore enhances land surface feedbacks to the atmosphere through changes in soil moisture and evaporative fraction. By altering the groundwater table depth, land use change and groundwater withdrawal can alter land surface response and feedback to the climate system.

  14. Perspective: The Climate-Population-Infrastructure Modeling and Simulation Fertile Area for New Research

    SciTech Connect (OSTI)

    Allen, Melissa R [ORNL; Fernandez, Steven J [ORNL; Walker, Kimberly A [ORNL; Fu, Joshua S [ORNL

    2014-01-01T23:59:59.000Z

    Managing the risks posed by climate change and extreme weather to energy production and delivery is a challenge to communities worldwide. As climate conditions change, populations will shift, and demand will re-locate; and networked infrastructures will evolve to accommodate new load centers, and, hopefully, minimize vulnerability to natural disaster. Climate effects such as sea level rise, increased frequency and intensity of natural disasters, force populations to move locations. Displaced population creates new demand for built infrastructure that in turn generates new economic activity that attracts new workers and associated households to the new locations. Infrastructures and their interdependencies will change in reaction to climate drivers as the networks expand into new population areas and as portions of the networks are abandoned as people leave. Thus, infrastructures will evolve to accommodate new load centers while some parts of the network are underused, and these changes will create emerging vulnerabilities. Forecasting the location of these vulnerabilities by combining climate predictions and agent based population movement models shows promise for defining these future population distributions and changes in coastal infrastructure configurations. By combining climate and weather data, engineering algorithms and social theory it has been only recently possible to examine electricity demand response to increased climactic temperatures, population relocation in response to extreme cyclonic events, consequent net population changes and new regional patterns in electricity demand. These emerging results suggest a research agenda of coupling these disparate modelling approaches to understand the implications of climate change for protecting the nation s critical infrastructure.

  15. Earth System Modeling Facility: Linking Climate to Cal-(IT)2 and OptIPuter

    E-Print Network [OSTI]

    Rose, Michael R.

    Earth System Modeling Facility: Linking Climate to Cal-(IT)2 and OptIPuter Charlie Zender in quantitatively-based environmental planning. #12;1. Overview Present: 1. Earth System Modeling Facility (ESMF) 2 and Planning #12;2. Earth System Modeling Facility (ESMF) Background: In 2003, NSF, UCI, & IGPP awarded $1.3M

  16. Agriculture and Climate Change in Global Scenarios: Why Don't the Models Agree

    SciTech Connect (OSTI)

    Nelson, Gerald; van der Mensbrugghe, Dominique; Ahammad, Helal; Blanc, Elodie; Calvin, Katherine V.; Hasegawa, Tomoko; Havlik, Petr; Heyhoe, Edwina; Kyle, G. Page; Lotze-Campen, Hermann; von Lampe, Martin; Mason d'Croz, Daniel; van Meijl, Hans; Mueller, C.; Reilly, J. M.; Robertson, Richard; Sands, Ronald; Schmitz, Christoph; Tabeau, Andrzej; Takahashi, Kiyoshi; Valin, Hugo; Willenbockel, Dirk

    2014-01-01T23:59:59.000Z

    Agriculture is unique among economic sectors in the nature of impacts from climate change. The production activity that transforms inputs into agricultural outputs makes direct use of weather inputs. Previous studies of the impacts of climate change on agriculture have reported substantial differences in outcomes of key variables such as prices, production, and trade. These divergent outcomes arise from differences in model inputs and model specification. The goal of this paper is to review climate change results and underlying determinants from a model comparison exercise with 10 of the leading global economic models that include significant representation of agriculture. By providing common productivity drivers that include climate change effects, differences in model outcomes are reduced. All models show higher prices in 2050 because of negative productivity shocks from climate change. The magnitude of the price increases, and the adaptation responses, differ significantly across the various models. Substantial differences exist in the structural parameters affecting demand, area, and yield, and should be a topic for future research.

  17. MODELING CLIMATE POLICY: ADDRESSING THE CHALLENGES OF POLICY EFFECTIVENESS AND

    E-Print Network [OSTI]

    on average do not appear to have been cost-effective in reducing energy consumption. iii #12;Acknowledgments aggressive cli- mate change policies. Policy makers and the public are concerned that such policies could, or economic sectors. The aim of this thesis is to show that the design of climate change policy has

  18. Integrating soil moisture and groundwater into climate models

    E-Print Network [OSTI]

    Krakauer, Nir Y.

    dNm dt =m Nm1- Nm -h Nh min1, Nm State transition to oscillatory solutions with efficient hunting: same initial and boundary conditions, but soil moisture set to seasonal climatology from DYNA experiments: Irrigation Simulate equilibrium climate with a mixed- layer ocean, year-2000 or 2050 (A1B

  19. The response of glaciers to intrinsic climate variability: observations and models of late-Holocene variations in the

    E-Print Network [OSTI]

    Roe, Gerard

    The response of glaciers to intrinsic climate variability: observations and models of late glacier variations due to natural climate variability and those due to true climate change is crucial for the interpretation and attribution of past glacier changes, and for the expectations of future changes. We explore

  20. Collaborative Research: Towards Advanced Understanding and Predictive Capability of Climate Change in the Arctic Using a High-Resolution Regional Arctic Climate Model

    SciTech Connect (OSTI)

    Cassano, John [Principal Investigator

    2013-06-30T23:59:59.000Z

    The primary research task completed for this project was the development of the Regional Arctic Climate Model (RACM). This involved coupling existing atmosphere, ocean, sea ice, and land models using the National Center for Atmospheric Research (NCAR) Community Climate System Model (CCSM) coupler (CPL7). RACM is based on the Weather Research and Forecasting (WRF) atmospheric model, the Parallel Ocean Program (POP) ocean model, the CICE sea ice model, and the Variable Infiltration Capacity (VIC) land model. A secondary research task for this project was testing and evaluation of WRF for climate-scale simulations on the large pan-Arctic model domain used in RACM. This involved identification of a preferred set of model physical parameterizations for use in our coupled RACM simulations and documenting any atmospheric biases present in RACM.

  1. Building America Best Practices Series: Volume 4; Builders and Buyers Handbook for Improving New Home Efficiency, Comfort, and Durability in the Mixed-Humid Climate Climate Regions

    SciTech Connect (OSTI)

    Baechler, M. C.; Love, P. M.

    2005-09-01T23:59:59.000Z

    This best practices guide is part of a series produced by Building America. The guide book is a resource to help builders large and small build high-quality, energy-efficient homes that achieve 30% energy savings in space conditioning and water heating in the mixed-humid climate region. The savings are in comparison with the 1993 Model Energy Code. The guide contains chapters for every member of the builder?s team?from the manager to the site planner to the designers, site supervisors, the trades, and marketers. There is also a chapter for homeowners on how to use the book to provide help in selecting a new home or builder.

  2. Improvements to model of projectile fragmentation

    E-Print Network [OSTI]

    S. Mallik; G. Chaudhuri; S. Das Gupta

    2011-08-22T23:59:59.000Z

    In a recent paper [Phys. Rev. C 044612 (2011)] we proposed a model for calculating cross-sections of various reaction products which arise from disintegration of projectile like fragment resulting from heavy ion collisions at intermediate or higher energy. The model has three parts: (1) abrasion, (2) disintegration of the hot abraded projectile like fragment (PLF) into nucleons and primary composites using a model of equilibrium statistical mechanics and (3) possible evaporation of hot primary composites. It was assumed that the PLF resulting from abrasion has one temperature T. Data suggested that while just one value of T seemed adequate for most cross-sections calculations, it failed when dealing with very peripheral collisions. We have now introduced a variable T=T(b) where b is the impact parameter of the collision. We argue there are data which not only show that T must be a function of b but, in addition, also point to an approximate value of T for a given b. We propose a very simple formula: T(b)=D_0+D_1(A_s(b)/A_0) where A_s(b) is the mass of the abraded PLF and A_0 is the mass of the projectile; D_0 and D_1 are constants. Using this model we compute cross-sections for several collisions and compare with data.

  3. Using Fault Model Enforcement to Improve Availability

    E-Print Network [OSTI]

    instead that a new approach, called fault model enforcement, that maps actual faults to expected faults on a constellation of interconnected systems--a typical example is cluster-based systems [4]. Traditional database centers around a set of closely guarded racks and data closets woven together by intricate networks

  4. Using Fault Model Enforcement to Improve Availability

    E-Print Network [OSTI]

    Martin, Richard P.

    that a new approach, called fault model enforcement, that maps actual faults to expected faults on a constellation of interconnected systems--a typical example is cluster-based systems [4]. Traditional database centers around a set of closely guarded racks and data closets woven together by intricate networks

  5. Fuel Cell System Improvement for Model-Based Diagnosis Analysis

    E-Print Network [OSTI]

    Paris-Sud XI, Université de

    Fuel Cell System Improvement for Model-Based Diagnosis Analysis Philippe Fiani & Michel Batteux of a model of a fuel cell system, in order to make it usable for model- based diagnosis methods. A fuel cell for the fuel cell stack but also for the system environment. In this paper, we present an adapted library which

  6. Cloud/Aerosol Parameterizations: Application and Improvement of General Circulation Models

    SciTech Connect (OSTI)

    Penner, Joyce

    2012-06-30T23:59:59.000Z

    One of the biggest uncertainties associated with climate models and climate forcing is the treatment of aerosols and their effects on clouds. The effect of aerosols on clouds can be divided into two components: The first indirect effect is the forcing associated with increases in droplet concentrations; the second indirect effect is the forcing associated with changes in liquid water path, cloud morphology, and cloud lifetime. Both are highly uncertain. This project applied a cloud-resolving model to understand the response of clouds under a variety of conditions to changes in aerosols. These responses are categorized according to the large-scale meteorological conditions that lead to the response. Meteorological conditions were sampled from various fields, which, together with a global aerosol model determination of the change in aerosols from present day to pre-industrial conditions, was used to determine a first order estimate of the response of global cloud fields to changes in aerosols. The response of the clouds in the NCAR CAM3 GCM coupled to our global aerosol model were tested by examining whether the response is similar to that of the cloud resolving model and methods for improving the representation of clouds and cloud/aerosol interactions were examined.

  7. The Faculty of Science and the Bolin Centre for Climate Research

    E-Print Network [OSTI]

    : Future Development of Climate and Earth System Models for Scientific and Policy Use Warren M. Washington of climate and Earth system models has been regarded primarily as the making of scientific tools to study, the development of climate and Earth system models became intimately linked to the need to not only improve our

  8. Future climate change under RCP emission scenarios with GISS ModelE2

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Nazarenko, L.; Schmidt, G. A.; Miller, R. L.; Tausnev, N.; Kelley, M.; Ruedy, R.; Russell, G. L.; Aleinov, I.; Bauer, M.; Bauer, S.; et al

    2015-03-01T23:59:59.000Z

    We examine the anthropogenically forced climate response for the 21st century representative concentration pathway (RCP) emission scenarios and their extensions for the period 2101–2500. The experiments were performed with ModelE2, a new version of the NASA Goddard Institute for Space Sciences (GISS) coupled general circulation model that includes three different versions for the atmospheric composition components: a noninteractive version (NINT) with prescribed composition and a tuned aerosol indirect effect (AIE), the TCAD version with fully interactive aerosols, whole-atmosphere chemistry, and the tuned AIE, and the TCADI version which further includes a parameterized first indirect aerosol effect on clouds. Each atmosphericmore »version is coupled to two different ocean general circulation models: the Russell ocean model (GISS-E2-R) and HYCOM (GISS-E2-H). By 2100, global mean warming in the RCP scenarios ranges from 1.0 to 4.5°#2;C relative to 1850–1860 mean temperature in the historical simulations. In the RCP2.6 scenario, the surface warming in all simulations stays below a 2#2;°C threshold at the end of the 21st century. For RCP8.5, the range is 3.5–4.5°#2;C at 2100. Decadally averaged sea ice area changes are highly correlated to global mean surface air temperature anomalies and show steep declines in both hemispheres, with a larger sensitivity during winter months. By the year 2500, there are complete recoveries of the globally averaged surface air temperature for all versions of the GISS climate model in the low-forcing scenario RCP2.6. TCADI simulations show enhanced warming due to greater sensitivity to CO?, aerosol effects, and greater methane feedbacks, and recovery is much slower in RCP2.6 than with the NINT and TCAD versions. All coupled models have decreases in the Atlantic overturning stream function by 2100. In RCP2.6, there is a complete recovery of the Atlantic overturning stream function by the year 2500 while with scenario RCP8.5, the E2-R climate model produces a complete shutdown of deep water formation in the North Atlantic.« less

  9. Improved load models for multi-area reliability calculations

    E-Print Network [OSTI]

    Pathak, Sanjesh

    1992-01-01T23:59:59.000Z

    IMPROVED LOAD MODELS FOR MULTI-AREA RELIABILITY CALCULATIONS A Thesis by SANJESH PATHAK Submitted to the Office of Graduate Studies of Texas ARM University in partial fulfillment of the requirements for the degree of MASTER OF SCIENCE May... 1992 Major Subject: Electrical Engineering IMPROVED LOAD MODELS FOR MULTI-AREA RELIABILITY CALCULATIONS A Thesis by SAN JESH PATHAK Approved as to style and content by: Chanan Singh (Chair of Committee) Prasad Enjeti (Member) Ces . Mal, e...

  10. Subgrid-Scale Mixing in Climate Models: A Novel Look at Diffusion, Accuracy, Stability and Climate Sensitivity

    SciTech Connect (OSTI)

    Rood, Richard B; Jablonowski, Christiane

    2012-10-31T23:59:59.000Z

    This project focuses on evaluating the role of subgrid-scale dissipation in the dynamical core of atmospheric models. All dynamical cores of atmospheric general circulation models (GCMs) employ some form of subgrid-scale dissipation, either explicitly specified or inherent in the chosen numerical schemes. The dissipation processes are needed to keep the simulation stable or to satisfy important physical properties, and the hope is that they capture and mimic in some poorly understood way the true processes at the unresolved subgrid scale. There is no physical basis that such dissipation can accomplish this. We originally posed a set of numerical test cases chosen or designed to isolate the role of the filters and fixers on both the dynamical variables (pressure, temperature, velocity, vorticity) and trace constituents. From these test case results, we synthesize the information to determine the impact of the subgrid-scale assumptions on weather and climate models.

  11. Climate Change Impacts for Conterminous USA: An Integrated Assessment Part 2. Models and Validation

    SciTech Connect (OSTI)

    Thomson, Allison M.; Rosenberg, Norman J.; Izaurralde, R Cesar C.; Brown, Robert A.

    2005-03-01T23:59:59.000Z

    As CO{sub 2} and other greenhouse gases accumulate in the atmosphere and contribute to rising global temperatures, it is important to examine how a changing climate may affect natural and managed ecosystems. In this series of papers, we study the impacts of climate change on agriculture, water resources and natural ecosystems in the conterminous United States using a suite of climate change predictions from General Circulation Models (GCMs) as described in Part 1. Here we describe the agriculture model EPIC and the HUMUS water model and validate them with historical crop yields and streamflow data. We compare EPIC simulated grain and forage crop yields with historical crop yields from the US Department of Agriculture and find an acceptable level of agreement for this study. The validation of HUMUS simulated streamflow with estimates of natural streamflow from the US Geological Survey shows that the model is able to reproduce significant relationships and capture major trends.

  12. Inferring Likelihoods and Climate System Characteristics from Climate Models and Multiple

    E-Print Network [OSTI]

    Haran, Murali

    the information contained in large-scale observational data sets with simulations of Earth system models in a sta

  13. A Hierarchical Evaluation of Regional Climate Simulations

    SciTech Connect (OSTI)

    Leung, Lai-Yung R.; Ringler, Todd; Collins, William D.; Taylor, Mark; Ashfaq, Moetasim

    2013-08-20T23:59:59.000Z

    Global climate models (GCMs) are the primary tools for predicting the evolution of the climate system. Through decades of development, GCMs have demonstrated useful skill in simulating climate at continental to global scales. However, large uncertainties remain in projecting climate change at regional scales, which limit our ability to inform decisions on climate change adaptation and mitigation. To bridge this gap, different modeling approaches including nested regional climate models (RCMs), global stretch-grid models, and global high-resolution atmospheric models have been used to provide regional climate simulations (Leung et al. 2003). In previous efforts to evaluate these approaches, isolating their relative merits was not possible because factors such as dynamical frameworks, physics parameterizations, and model resolutions were not systematically constrained. With advances in high performance computing, it is now feasible to run coupled atmosphere-ocean GCMs at horizontal resolution comparable to what RCMs use today. Global models with local refinement using unstructured grids have become available for modeling regional climate (e.g., Rauscher et al. 2012; Ringler et al. 2013). While they offer opportunities to improve climate simulations, significant efforts are needed to test their veracity for regional-scale climate simulations.

  14. Scaling Process Studies and Observations in the Arctic for Improved Climate Predictability

    E-Print Network [OSTI]

    Hubbard, Susan

    and representation of that knowledge in Earth System models. Geomorphological units, including thaw lakes, drained

  15. Modelling Shea under Climate Scenarios Philip J Platts, Mahesh Poudyal, Colin J McClean

    E-Print Network [OSTI]

    Marchant, Rob

    1 Modelling Shea under Climate Scenarios Philip J Platts, Mahesh Poudyal, Colin J McClean INNOVKAR Work Package 2 (Task 2.7) Annual Summary Report 2010 Citation: Platts PJ, Poudyal M, McClean CJ (2010-model' predictions (Platts et al., 2008). This procedure was repeated ten times, each time generating a new

  16. RESEARCH ARTICLE A novel soil organic C model using climate, soil type

    E-Print Network [OSTI]

    Paris-Sud XI, Université de

    RESEARCH ARTICLE A novel soil organic C model using climate, soil type and management data-Verlag, France 2012 Abstract This report evidences factors controlling soil or- ganic carbon at the national scale by modelling data of 2,158 soil samples from France. The global soil carbon amount, of about 1

  17. Development of a High-Performance Office Building Simulation Model for a Hot and Humid Climate 

    E-Print Network [OSTI]

    Cho, S.; Haberl, J.

    2009-01-01T23:59:59.000Z

    applicable to office buildings in hot and humid climates and to develop a high-performance (maximum energy-efficient) building model that only uses technologies readily available in the contemporary market. The high-performance model showed 48% total energy...

  18. Coupling of Integrated Biosphere Simulator to Regional Climate Model version 3

    E-Print Network [OSTI]

    Winter, Jonathan (Jonathan Mark)

    2006-01-01T23:59:59.000Z

    Presented in this thesis is a description of the coupling of Integrated Biosphere Simulator (IBIS) to Regional Climate Model version 3 (RegCM3), and an assessment of the coupled model (RegCM3-IBIS). RegCM3 is a 3-dimensional, ...

  19. A climate sensitivity estimate using Bayesian fusion of instrumental observations and an Earth System model

    E-Print Network [OSTI]

    sensitivity estimate using Bayesian fusion of instrumental observations and an Earth System model, J. Geophys System model Roman Olson,1 Ryan Sriver,1 Marlos Goes,2,3 Nathan M. Urban,4,5 H. Damon Matthews,6 MuraliA climate sensitivity estimate using Bayesian fusion of instrumental observations and an Earth

  20. Why are climate models reproducing the observed global surface warming so well?

    E-Print Network [OSTI]

    Fischlin, Andreas

    Why are climate models reproducing the observed global surface warming so well? Reto Knutti1 global surface warming so well?, Geophys. Res. Lett., 35, L18704, doi:10.1029/ 2008GL034932. 1 models reproduce the observed surface warming better than one would expect given the uncertainties

  1. Modeling High-Impact Weather and Climate: Lessons From a Tropical Cyclone Perspective

    SciTech Connect (OSTI)

    Done, James; Holland, Greg; Bruyere, Cindy; Leung, Lai-Yung R.; Suzuki-Parker, Asuka

    2013-10-19T23:59:59.000Z

    Although the societal impact of a weather event increases with the rarity of the event, our current ability to assess extreme events and their impacts is limited by not only rarity but also by current model fidelity and a lack of understanding of the underlying physical processes. This challenge is driving fresh approaches to assess high-impact weather and climate. Recent lessons learned in modeling high-impact weather and climate are presented using the case of tropical cyclones as an illustrative example. Through examples using the Nested Regional Climate Model to dynamically downscale large-scale climate data the need to treat bias in the driving data is illustrated. Domain size, location, and resolution are also shown to be critical and should be guided by the need to: include relevant regional climate physical processes; resolve key impact parameters; and to accurately simulate the response to changes in external forcing. The notion of sufficient model resolution is introduced together with the added value in combining dynamical and statistical assessments to fill out the parent distribution of high-impact parameters. Finally, through the example of a tropical cyclone damage index, direct impact assessments are resented as powerful tools that distill complex datasets into concise statements on likely impact, and as highly effective communication devices.

  2. IMPROVEMENTS IN MODELLING DISSOLVED OXYGEN IN ACTIVATED SLUDGE SYSTEMS

    E-Print Network [OSTI]

    Wells, Scott A.

    1 IMPROVEMENTS IN MODELLING DISSOLVED OXYGEN IN ACTIVATED SLUDGE SYSTEMS Jacek Makinia*, Scott A in a full-scale activated sludge reactor. The Activated Sludge Model No. 1 was used to describe for dissolved oxygen. KEYWORDS Activated sludge; dispersion; dissolved oxygen dynamics; mass transfer

  3. RESEARCH ARTICLE A model for improving microbial biofuel production using

    E-Print Network [OSTI]

    Dunlop, Mary

    RESEARCH ARTICLE A model for improving microbial biofuel production using a synthetic feedback loop be compared. We propose a model for microbial biofuel production where a synthetic control system is used to increase cell viability and biofuel yields. Although microbes can be engineered to produce biofuels

  4. Recent Advances in Regional Climate System Modeling and Climate Change Analyses of Extreme Heat

    E-Print Network [OSTI]

    Miller, Norman L.

    2004-01-01T23:59:59.000Z

    California hydrology. J. Am. Water Resources Association 39,Land Surface and Ground Water Model for use in WatershedN.L. , 2003: California Water Resources Research, CEC Sept

  5. Oracle-Based Optimization Applied to Climate Model Calibration

    E-Print Network [OSTI]

    Beltran-Royo, Cesar

    and earth system modelling since even so-called intermediate complexity models, such as the one used

  6. Sandia National Laboratories: Modeling & Analysis

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    from improved climate models to performance models for underground waste storage to 3D printing and digital rock physics. Marianne Walck (Director ... NASA Award for Marginal...

  7. Towards Ultra-High Resolution Models of Climate and Weather To appear in the International Journal of High Performance Computing Applications, 2008.

    E-Print Network [OSTI]

    Oliker, Leonid

    of anthropogenic climate change are highly dependent on cloud-radiation interactions. In this paper, we Keywords Climate model, atmospheric general circulation model, finite volume model, global warming scientists today, with economic ramifications in the trillions of dollars. Effectively performing

  8. Analysis of permafrost thermal dynamics and response to climate change in the CMIP5 Earth System Models

    E-Print Network [OSTI]

    Koven, C.D.

    2014-01-01T23:59:59.000Z

    coupled climate-carbon earth system models part i: PhysicalChange in the CMIP5 Earth System Models  Koven, C.D. , W.J.output from a set of Earth System Models (ESMs) (Table 1)

  9. CONSEQUENCES OF SPATIAL AND TEMPORAL CLIMATE VARIABILITY FOR SPECIES DISTRIBUTION MODELING

    E-Print Network [OSTI]

    Fernandez, Miguel

    2013-01-01T23:59:59.000Z

    Climate change, habitat loss, protected areas and the climate adaptation potential of species in Mediterranean

  10. Improved Climate Prediction through a System Level Understanding of Arctic Terrestrial Ecosystems

    E-Print Network [OSTI]

    Hubbard, Susan

    understood and many remain uncertain in terms of their representation in Earth System models. Increasing our System models. By extending an already well-established framework for fractional sub-grid area System Model grid cell (i.e., 30x30 km grid size). This vision includes mechanistic studies in the field

  11. A Large-Scale, High-Resolution Hydrological Model Parameter Data Set for Climate Change Impact Assessment for the Conterminous US

    SciTech Connect (OSTI)

    Oubeidillah, Abdoul A [ORNL] [ORNL; Kao, Shih-Chieh [ORNL] [ORNL; Ashfaq, Moetasim [ORNL] [ORNL; Naz, Bibi S [ORNL] [ORNL; Tootle, Glenn [University of Alabama, Tuscaloosa] [University of Alabama, Tuscaloosa

    2014-01-01T23:59:59.000Z

    To extend geographical coverage, refine spatial resolution, and improve modeling efficiency, a computation- and data-intensive effort was conducted to organize a comprehensive hydrologic dataset with post-calibrated model parameters for hydro-climate impact assessment. Several key inputs for hydrologic simulation including meteorologic forcings, soil, land class, vegetation, and elevation were collected from multiple best-available data sources and organized for 2107 hydrologic subbasins (8-digit hydrologic units, HUC8s) in the conterminous United States at refined 1/24 (~4 km) spatial resolution. Using high-performance computing for intensive model calibration, a high-resolution parameter dataset was prepared for the macro-scale Variable Infiltration Capacity (VIC) hydrologic model. The VIC simulation was driven by DAYMET daily meteorological forcing and was calibrated against USGS WaterWatch monthly runoff observations for each HUC8. The results showed that this new parameter dataset may help reasonably simulate runoff at most US HUC8 subbasins. Based on this exhaustive calibration effort, it is now possible to accurately estimate the resources required for further model improvement across the entire conterminous United States. We anticipate that through this hydrologic parameter dataset, the repeated effort of fundamental data processing can be lessened, so that research efforts can emphasize the more challenging task of assessing climate change impacts. The pre-organized model parameter dataset will be provided to interested parties to support further hydro-climate impact assessment.

  12. Final Report on Hierarchical Coupled Modeling and Prediction of Regional Climate Change in the Atlantic Sector

    SciTech Connect (OSTI)

    Saravanan, Ramalingam [Texas A& M University

    2011-10-30T23:59:59.000Z

    During the course of this project, we have accomplished the following: a) Carried out studies of climate changes in the past using a hierarchy of intermediate coupled models (Chang et al., 2008; Wan et al 2009; Wen et al., 2010a,b) b) Completed the development of a Coupled Regional Climate Model (CRCM; Patricola et al., 2011a,b) c) Carried out studies testing hypotheses testing the origin of systematic errors in the CRCM (Patricola et al., 2011a,b) d) Carried out studies of the impact of air-sea interaction on hurricanes, in the context of barrier layer interactions (Balaguru et al)

  13. Accounting for Global Climate Model Projection Uncertainty in Modern Statistical Downscaling

    SciTech Connect (OSTI)

    Johannesson, G

    2010-03-17T23:59:59.000Z

    Future climate change has emerged as a national and a global security threat. To carry out the needed adaptation and mitigation steps, a quantification of the expected level of climate change is needed, both at the global and the regional scale; in the end, the impact of climate change is felt at the local/regional level. An important part of such climate change assessment is uncertainty quantification. Decision and policy makers are not only interested in 'best guesses' of expected climate change, but rather probabilistic quantification (e.g., Rougier, 2007). For example, consider the following question: What is the probability that the average summer temperature will increase by at least 4 C in region R if global CO{sub 2} emission increases by P% from current levels by time T? It is a simple question, but one that remains very difficult to answer. It is answering these kind of questions that is the focus of this effort. The uncertainty associated with future climate change can be attributed to three major factors: (1) Uncertainty about future emission of green house gasses (GHG). (2) Given a future GHG emission scenario, what is its impact on the global climate? (3) Given a particular evolution of the global climate, what does it mean for a particular location/region? In what follows, we assume a particular GHG emission scenario has been selected. Given the GHG emission scenario, the current batch of the state-of-the-art global climate models (GCMs) is used to simulate future climate under this scenario, yielding an ensemble of future climate projections (which reflect, to some degree our uncertainty of being able to simulate future climate give a particular GHG scenario). Due to the coarse-resolution nature of the GCM projections, they need to be spatially downscaled for regional impact assessments. To downscale a given GCM projection, two methods have emerged: dynamical downscaling and statistical (empirical) downscaling (SDS). Dynamic downscaling involves configuring and running a regional climate model (RCM) nested within a given GCM projection (i.e., the GCM provides bounder conditions for the RCM). On the other hand, statistical downscaling aims at establishing a statistical relationship between observed local/regional climate variables of interest and synoptic (GCM-scale) climate predictors. The resulting empirical relationship is then applied to future GCM projections. A comparison of the pros and cons of dynamical versus statistical downscaling is outside the scope of this effort, but has been extensively studied and the reader is referred to Wilby et al. (1998); Murphy (1999); Wood et al. (2004); Benestad et al. (2007); Fowler et al. (2007), and references within those. The scope of this effort is to study methodology, a statistical framework, to propagate and account for GCM uncertainty in regional statistical downscaling assessment. In particular, we will explore how to leverage an ensemble of GCM projections to quantify the impact of the GCM uncertainty in such an assessment. There are three main component to this effort: (1) gather the necessary climate-related data for a regional SDS study, including multiple GCM projections, (2) carry out SDS, and (3) assess the uncertainty. The first step is carried out using tools written in the Python programming language, while analysis tools were developed in the statistical programming language R; see Figure 1.

  14. Atmospheric Properties from the 2006 Niamey Deployment and Climate Simulation with a Geodesic Grid Coupled Climate Model Fourth Quarter 2008

    SciTech Connect (OSTI)

    JH Mather; DA Randall; CJ Flynn

    2008-09-30T23:59:59.000Z

    In 2008, the Atmospheric Radiation Measurement (ARM) Program and the Climate Change Prediction Program (CCPP) have been asked to produce joint science metrics. For CCPP, the metrics will deal with a decade-long control simulation using geodesic grid-coupled climate model. For ARM, the metrics will deal with observations associated with the 2006 deployment of the ARM Mobile Facility (AMF) to Niamey, Niger. Specifically, ARM has been asked to deliver data products for Niamey that describe cloud, aerosol, and dust properties. The first quarter milestone was the initial formulation of the algorithm for retrieval of these properties. The second quarter milestone included the time series of ARM-retrieved cloud properties and a year-long CCPP control simulation. The third quarter milestone included the time series of ARM-retrieved aerosol optical depth and a three-year CCPP control simulation. This final fourth quarter milestone includes the time-series of aerosol and dust properties and a decade-long CCPP control simulation.

  15. Climate WorkshopsClimate Workshops for Department Chairsp

    E-Print Network [OSTI]

    Tilbury, Dawn

    Climate WorkshopsClimate Workshops for Department Chairsp University of Wisconsin ADVANCE-IT Slides) #12;Why focus on departmental climate? Individuals experience climate in their immediate workplace negative climate than male faculty Improving department climate is critical for retention and advancement

  16. The Thermodynamic Influence of Subgrid Orography in a Global Climate Model

    SciTech Connect (OSTI)

    Ghan, Steven J.; Bian, Xindi; Hunt, Allen G.; Coleman, Andre M.

    2002-11-01T23:59:59.000Z

    Assessments of the impacts of climate change typically require information at scales of 10 km or less. Such a resolution will not be achieved by global climate models for many years. We have developed an alternative to explicit resolution that can meet the needs of climate change impact assessment now. We have applied to a global climate model a physically-based subgrid-scale treatment of the influence of orography on temperature, clouds, precipitation, and land surface hydrology. The treatment represents subgrid variations in surface elevation in terms of fractional area distributions of discrete elevation classes. For each class it calculates the height rise/descent of air parcels traveling through the grid cell, and applies the influence of the rise/descent to the temperature and humidity profiles of the elevation class. Cloud, radiative, and surface processes are calculated separately for each elevation class using the same physical parameterizations used by the model without the subgrid parameterization. The simulated climate fields for each elevation class can then be distributed in post-processing according to the spatial distribution of surface elevation within each grid cell. Parallel 10-year simulations with and without the subgrid treatment have been performed. The simulated temperature, precipitation and snow water are mapped to 2.5 minute (~5 km) resolution and compared with gridded analyses of station measurements. The simulation with the subgrid scheme produces a much more realistic distribution of snow water and significantly more realistic distributions of temperature and precipitation than the simulation without the subgrid scheme. Moreover, the grid cell means of most other fields are virtually unchanged by the subgrid scheme. This suggests that the tuning of the climate model without the subgrid scheme is also applicable to the model with the scheme.

  17. Population and Climate Change:Population and Climate Change: Coupling Population Models withCoupling Population Models with

    E-Print Network [OSTI]

    Kalnay, Eugenia

    Coupling Population Models with Earth System ModelsEarth System Models Eugenia Kalnay, Safa Motesharrei, Jorge Rivas Change: Fully Coupling Population and Earth System Models" My research at the U. of Maryland #12

  18. Improving the Contribution of Economic Models in Evaluating Industrial Energy Efficiency Improvements 

    E-Print Network [OSTI]

    Laitner, J. A.

    2007-01-01T23:59:59.000Z

    Traditional representation of improved end-use efficiency in the manufacturing sector has tended to assume “a net cost” perspective. In other words, the assumption for many models is that any change within the energy end-use patterns must imply a...

  19. Investigation of Aerosol Indirect Effects using a Cumulus Microphysics Parameterization in a Regional Climate Model

    SciTech Connect (OSTI)

    Lim, Kyo-Sun; Fan, Jiwen; Leung, Lai-Yung R.; Ma, Po-Lun; Singh, Balwinder; Zhao, Chun; Zhang, Yang; Zhang, Guang; Song, Xiaoliang

    2014-01-29T23:59:59.000Z

    A new Zhang and McFarlane (ZM) cumulus scheme includes a two-moment cloud microphysics parameterization for convective clouds. This allows aerosol effects to be investigated more comprehensively by linking aerosols with microphysical processes in both stratiform clouds that are explicitly resolved and convective clouds that are parameterized in climate models. This new scheme is implemented in the Weather Research and Forecasting (WRF) model, which is coupled with the physics and aerosol packages from the Community Atmospheric Model version 5 (CAM5). A test case of July 2008 during the East Asian summer monsoon is selected to evaluate the performance of the new ZM scheme and to investigate aerosol effects on monsoon precipitation. The precipitation and radiative fluxes simulated by the new ZM scheme show a better agreement with observations compared to simulations with the original ZM scheme that does not include convective cloud microphysics and aerosol convective cloud interactions. Detailed analysis suggests that an increase in detrained cloud water and ice mass by the new ZM scheme is responsible for this improvement. To investigate precipitation response to increased anthropogenic aerosols, a sensitivity experiment is performed that mimics a clean environment by reducing the primary aerosols and anthropogenic emissions to 30% of that used in the control simulation of a polluted environment. The simulated surface precipitation is reduced by 9.8% from clean to polluted environment and the reduction is less significant when microphysics processes are excluded from the cumulus clouds. Ensemble experiments with ten members under each condition (i.e., clean and polluted) indicate similar response of the monsoon precipitation to increasing aerosols.

  20. Demonstrating the improvement of predictive maturity of a computational model

    SciTech Connect (OSTI)

    Hemez, Francois M [Los Alamos National Laboratory; Unal, Cetin [Los Alamos National Laboratory; Atamturktur, Huriye S [CLEMSON UNIV.

    2010-01-01T23:59:59.000Z

    We demonstrate an improvement of predictive capability brought to a non-linear material model using a combination of test data, sensitivity analysis, uncertainty quantification, and calibration. A model that captures increasingly complicated phenomena, such as plasticity, temperature and strain rate effects, is analyzed. Predictive maturity is defined, here, as the accuracy of the model to predict multiple Hopkinson bar experiments. A statistical discrepancy quantifies the systematic disagreement (bias) between measurements and predictions. Our hypothesis is that improving the predictive capability of a model should translate into better agreement between measurements and predictions. This agreement, in turn, should lead to a smaller discrepancy. We have recently proposed to use discrepancy and coverage, that is, the extent to which the physical experiments used for calibration populate the regime of applicability of the model, as basis to define a Predictive Maturity Index (PMI). It was shown that predictive maturity could be improved when additional physical tests are made available to increase coverage of the regime of applicability. This contribution illustrates how the PMI changes as 'better' physics are implemented in the model. The application is the non-linear Preston-Tonks-Wallace (PTW) strength model applied to Beryllium metal. We demonstrate that our framework tracks the evolution of maturity of the PTW model. Robustness of the PMI with respect to the selection of coefficients needed in its definition is also studied.

  1. Collaborative Proposal: Transforming How Climate System Models are Used: A Global, Multi-Resolution Approach

    SciTech Connect (OSTI)

    Estep, Donald

    2013-04-15T23:59:59.000Z

    Despite the great interest in regional modeling for both weather and climate applications, regional modeling is not yet at the stage that it can be used routinely and effectively for climate modeling of the ocean. The overarching goal of this project is to transform how climate models are used by developing and implementing a robust, efficient, and accurate global approach to regional ocean modeling. To achieve this goal, we will use theoretical and computational means to resolve several basic modeling and algorithmic issues. The first task is to develop techniques for transitioning between parameterized and high-fidelity regional ocean models as the discretization grid transitions from coarse to fine regions. The second task is to develop estimates for the error in scientifically relevant quantities of interest that provide a systematic way to automatically determine where refinement is needed in order to obtain accurate simulations of dynamic and tracer transport in regional ocean models. The third task is to develop efficient, accurate, and robust time-stepping schemes for variable spatial resolution discretizations used in regional ocean models of dynamics and tracer transport. The fourth task is to develop frequency-dependent eddy viscosity finite element and discontinuous Galerkin methods and study their performance and effectiveness for simulation of dynamics and tracer transport in regional ocean models. These four projects share common difficulties and will be approach using a common computational and mathematical toolbox. This is a multidisciplinary project involving faculty and postdocs from Colorado State University, Florida State University, and Penn State University along with scientists from Los Alamos National Laboratory. The completion of the tasks listed within the discussion of the four sub-projects will go a long way towards meeting our goal of developing superior regional ocean models that will transform how climate system models are used.

  2. On the Use of Computational Models for Wave Climate Assessment in Support of the Wave Energy Industry

    E-Print Network [OSTI]

    Victoria, University of

    On the Use of Computational Models for Wave Climate Assessment in Support of the Wave Energy On the Use of Computational Models for Wave Climate Assessment in Support of the Wave Energy Industry Effective, economic extraction of ocean wave energy requires an intimate under- standing of the ocean wave

  3. Probabilistic Forecast for 21st Century Climate Based on Uncertainties in Emissions (without Policy) and Climate Parameters

    E-Print Network [OSTI]

    Sokolov, Andrei P.

    The MIT Integrated Global System Model is used to make probabilistic projections of climate change from 1861 to 2100. Since the model's first projections were published in 2003 substantial improvements have been made to ...

  4. Sandia National Laboratories: Climate

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Climate A Model for the Nation: Promoting Education and Innovation in Vermont's Electricity Sector On May 8, 2012, in Climate, Customers & Partners, Energy, Energy Surety,...

  5. YEAR PROGRESS REPORT TITLE: Global Modeling of Tropospheric Aerosols and Their Contribution to Climate Variation

    E-Print Network [OSTI]

    as CCN would cool the climate system by about ­1.16 W m-2 , while carbonaceous aerosols from fossil fuel combustion acting alone may cool the system by about ­0.52 W m-2 (see Table 1). However, because-1- GACP 2nd YEAR PROGRESS REPORT TITLE: Global Modeling of Tropospheric Aerosols

  6. Nuclear winter revisited with a modern climate model and current nuclear arsenals: Still catastrophic consequences

    E-Print Network [OSTI]

    Stenchikov, Georgiy L.

    drops at the surface that would threaten global agriculture for at least a year. The global nuclear of world agriculture, the arms race and cold war ended. Since then, the global nuclear arsenal has beenNuclear winter revisited with a modern climate model and current nuclear arsenals: Still

  7. A Multi-Model Assessment of Regional Climate Disparities Caused by Solar Geoengineering

    E-Print Network [OSTI]

    Robock, Alan

    1 A Multi-Model Assessment of Regional Climate Disparities Caused by Solar Geoengineering Normal University, Beijing, China. 9 School of Engineering and Applied Sciences, Harvard University levels. G1 involves a reduction in solar irradiance to counteract the radiative forcing5 in abrupt4xCO2

  8. Common Metadata for Climate Modelling Digital Repositories CIM-enabled OASIS

    E-Print Network [OSTI]

    Common Metadata for Climate Modelling Digital Repositories CIM-enabled OASIS CERFACS Technical-1.2.1 Scientific Digital Repositories DOCUMENT Deliverable D5.7 Month 36 Deliverable Title CIM-enabled OASIS describes the adaption of the OASIS4 coupler so that it can use a CIM XML file for its configuration instead

  9. Use of models and observations to assess trends in the 19502005 water balance and climate

    E-Print Network [OSTI]

    ) was about 50% of normal during 2000­2001. The ensuing drought-related water shortage led to seriousUse of models and observations to assess trends in the 1950­2005 water balance and climate of Upper-driven interannual (and longer) variability is evident. Evaporation and the other components of the water balance

  10. Selected translated abstracts of Russian-language climate-change publications. 4: General circulation models

    SciTech Connect (OSTI)

    Burtis, M.D. [comp.] [Oak Ridge National Lab., TN (United States). Carbon Dioxide Information Analysis Center; Razuvaev, V.N.; Sivachok, S.G. [All-Russian Research Inst. of Hydrometeorological Information--World Data Center, Obninsk (Russian Federation)

    1996-10-01T23:59:59.000Z

    This report presents English-translated abstracts of important Russian-language literature concerning general circulation models as they relate to climate change. Into addition to the bibliographic citations and abstracts translated into English, this report presents the original citations and abstracts in Russian. Author and title indexes are included to assist the reader in locating abstracts of particular interest.

  11. Net accumulation of the Greenland ice sheet: High resolution modeling of climate changes

    E-Print Network [OSTI]

    Born, Andreas

    : Kiilsholm, S., J. H. Christensen, K. Dethloff, and A. Rinke, Net accumulation of the Greenland ice sheetNet accumulation of the Greenland ice sheet: High resolution modeling of climate changes Sissi, Denmark Klaus Dethloff and Annette Rinke Alfred Wegener Institute for Polar and Marine Research

  12. Computable General Equilibrium Models for the Analysis of Energy and Climate Policies

    E-Print Network [OSTI]

    Wing, Ian Sue

    Computable General Equilibrium Models for the Analysis of Energy and Climate Policies Ian Sue Wing of energy and environmental policies. Perhaps the most important of these applications is the analysis Change, MIT Prepared for the International Handbook of Energy Economics Abstract This chapter is a simple

  13. Modeling the climate response to a massive methane release from gas hydrates

    E-Print Network [OSTI]

    Renssen, Hans

    Modeling the climate response to a massive methane release from gas hydrates H. Renssen and C. J release from gas hydrates, Paleoceanography, 19, PA2010, doi:10.1029/2003PA000968. 1. Introduction [2] Catastrophic releases of methane gas from hydrates (clathrates) have been mentioned to be responsible for rapid

  14. Evaluating the present-day simulation of clouds, precipitation, and radiation in climate models

    E-Print Network [OSTI]

    Robert, Pincus

    , and net cloud radiative effect, projected cloud fraction, and surface precipitation rate) over the globalEvaluating the present-day simulation of clouds, precipitation, and radiation in climate models] This paper describes a set of metrics for evaluating the simulation of clouds, radiation, and precipitation

  15. Climate Change Policy: What Do the Models Tell Us?

    E-Print Network [OSTI]

    Pindyck, Robert S.

    Very little. A plethora of integrated assessment models (IAMs) have been constructed and used to estimate the social cost of carbon (SCC) and evaluate alternative abatement policies. These models have crucial flaws that ...

  16. Weakly screened thermonuclear reactions in astrophysical plasmas: Improving Salpeter's model

    E-Print Network [OSTI]

    Theodore E. Liolios

    2003-06-23T23:59:59.000Z

    This paper presents a detailed study of the electron degeneracy and nonlinear screening effects which play a crucial role in the validity of Salpeter's weak-screening model. The limitations of that model are investigated and an improved one is proposed which can take into account nonlinear screening effects. Its application to the solar pp reaction derives an accurate screening enhancement factor and provides a very reliable estimation of the associated neutrino flux uncertanties.

  17. Construction Logistics Improvements using the SCOR model Tornet Case

    E-Print Network [OSTI]

    Paris-Sud XI, Université de

    Construction Logistics Improvements using the SCOR model ­Tornet Case Fredrik Persson1 , Jonas over the last decades. Initiatives such as Lean Construction and Prefabrication have emerged in the construction industry to reduce the cost of house production and thereby the cost of the house itself

  18. Building a WIM Data Archive for Improved Modeling, Design, and

    E-Print Network [OSTI]

    Bertini, Robert L.

    Building a WIM Data Archive for Improved Modeling, Design, and Rating Christopher Monsere Assistant, Washington, D.C. August 6, 2008 #12;Outline Data Almanac PORTAL WIM Archive Quality Control Sample Uses Redundant Array of Independent Disks (RAID) Web Interface #12;QUALITY CONTROL 14 #12;WIM Archive Quality

  19. Can remote sensing of land cover improve species distribution modelling?

    E-Print Network [OSTI]

    Bradley, Bethany

    COMMENTARY Can remote sensing of land cover improve species distribution modelling? Remote sensing- guish among broad classes of vegetation. However, the applicability of remote sensing to classification like from remote sensing ­ a map of tree species ­ and what can be delivered ­ a map of forest types

  20. Simulation of polar stratospheric clouds in the specified dynamics version of the whole atmosphere community climate model

    E-Print Network [OSTI]

    Wegner, T.

    We evaluate the simulation of polar stratospheric clouds (PSCs) in the Specified Dynamics version of the Whole Atmosphere Community Climate Model for the Antarctic winter 2005. In this model, PSCs are assumed to form ...

  1. A look at the ocean in the EC-Earth climate model Andreas Sterl Richard Bintanja Laurent Brodeau Emily Gleeson

    E-Print Network [OSTI]

    Haak, Hein

    to the special issue on EC-Earth, a global climate and earth system model based on the seasonal forecast system-011-1239-2 #12;phytoplankton) processes are involved. To study such complex interactions, Earth System Models

  2. Global vegetation model diversity and the risks of climate-driven ecosystem shifts

    SciTech Connect (OSTI)

    Bond-Lamberty, Benjamin

    2013-11-08T23:59:59.000Z

    Climate change is modifying global biogeochemical cycles, and is expected to exert increasingly large effects in the future. How these changes will in turn affect and interact with the structure and function of particular ecosystems is unclear, however, both because of scientific uncertainties and the very diversity of global vegetation models in use. Writing in Environmental Research Letters, Warszawski et al. (1) aggregate results from a group of models, across a range of emissions scenarios and climate data, to investigate these risks. Although the models frequently disagree about which specific regions are at risk, they consistently predict a greater chance of ecosystem restructuring with more warming; this risk roughly doubles between 2 and 3 °C increases in global mean temperature. The innovative work of Warszawski et al. represents an important first step towards fully consistent multi-model, multi-scenario assessments of the future risks to global ecosystems.

  3. The uses and limits of economic models as a climate change policy tool: A summary report

    SciTech Connect (OSTI)

    Zimmerman, M.B.; Nitze, W.A.

    1991-01-01T23:59:59.000Z

    The Alliance to Save Energy initiated this workshop as a means of bringing climate change policy makers and economists together on the eve of the opening negotiating session for a climate change convention. The one and one-half day workshop was attended by 16 analysts who provided presentations on modeling approaches. There is a need for policy makers to be better able to evaluate the growing literature estimating the potential cost of policy options. Our hope is that this report, to be presented at the conclusion of the negotiations on the framework convention on climate change at the Earth Summit in Brazil, will help policy makers in the US and elsewhere evaluate the costs and benefits of national climate change mitigation policies. Although it is still unclear how far the convention will go in requiring emissions reductions, many countries are proceeding with detailed plans to reduce domestic carbon dioxide (CO{sub 2}) emissions. Our goal in holding the workshop and writing this report is to spark a new level of dialogue between the producers and users of information on the costs and benefits of climate mitigation policies leading to the development of more cost-effective policy solutions at the national and international levels.

  4. The uses and limits of economic models as a climate change policy tool: A summary report

    SciTech Connect (OSTI)

    Zimmerman, M.B.; Nitze, W.A.

    1991-12-31T23:59:59.000Z

    The Alliance to Save Energy initiated this workshop as a means of bringing climate change policy makers and economists together on the eve of the opening negotiating session for a climate change convention. The one and one-half day workshop was attended by 16 analysts who provided presentations on modeling approaches. There is a need for policy makers to be better able to evaluate the growing literature estimating the potential cost of policy options. Our hope is that this report, to be presented at the conclusion of the negotiations on the framework convention on climate change at the Earth Summit in Brazil, will help policy makers in the US and elsewhere evaluate the costs and benefits of national climate change mitigation policies. Although it is still unclear how far the convention will go in requiring emissions reductions, many countries are proceeding with detailed plans to reduce domestic carbon dioxide (CO{sub 2}) emissions. Our goal in holding the workshop and writing this report is to spark a new level of dialogue between the producers and users of information on the costs and benefits of climate mitigation policies leading to the development of more cost-effective policy solutions at the national and international levels.

  5. Impact of Agricultural Practice on Regional Climate in a CoupledLand Surface Mesoscale Model

    SciTech Connect (OSTI)

    Cooley, H.S.; Riley, W.J.; Torn, M.S.; He, Y.

    2004-07-01T23:59:59.000Z

    The land surface has been shown to form strong feedbacks with climate due to linkages between atmospheric conditions and terrestrial ecosystem exchanges of energy, momentum, water, and trace gases. Although often ignored in modeling studies, land management itself may form significant feedbacks. Because crops are harvested earlier under drier conditions, regional air temperature, precipitation, and soil moisture, for example, affect harvest timing, particularly of rain-fed crops. This removal of vegetation alters the land surface characteristics and may, in turn, affect regional climate. We applied a coupled climate(MM5) and land-surface (LSM1) model to examine the effects of early and late winter wheat harvest on regional climate in the Department of Energy Atmospheric Radiation Measurement (ARM) Climate Research Facility in the Southern Great Plains, where winter wheat accounts for 20 percent of the land area. Within the winter wheat region, simulated 2 m air temperature was 1.3 C warmer in the Early Harvest scenario at mid-day averaged over the two weeks following harvest. Soils in the harvested area were drier and warmer in the top 10 cm and wetter in the 10-20 cm layer. Midday soils were 2.5 C warmer in the harvested area at mid-day averaged over the two weeks following harvest. Harvest also dramatically altered latent and sensible heat fluxes. Although differences between scenarios diminished once both scenarios were harvested, the short-term impacts of land management on climate were comparable to those from land cover change demonstrated in other studies.

  6. A climate-soil-crop model to evaluate drought incidence and severity

    E-Print Network [OSTI]

    Puvirajasinghe, Patrick

    1982-01-01T23:59:59.000Z

    A CLINATE-SOIL-CROP MODEL TO EVALUATE DROUGHT INCIDENCE AND SEVERITY A Thesis by PATRICK PUVIRAJASINGHE Submitted to the Graduate College of Texas A&M University in partial fulfillment of the requirement for the degree of MASTER OF SCIENCE... August 1982 Major Subject: Agronomy A CLIMATE-SOIL-CROP MODEL TO EVALUATE DROUGHT INCIDENCE AND SEVERITY A Thesis by PATRICK PUVIRAJASINGHE Approved as to style and content by: (Chairman of Committee) 5' 9 (Member) (Me r) (Member ead of e...

  7. Uncertainty in Simulating Wheat Yields Under Climate Change

    SciTech Connect (OSTI)

    Asseng, S.; Ewert, F.; Rosenzweig, C.; Jones, J.W.; Hatfield, Jerry; Ruane, Alex; Boote, K. J.; Thorburn, Peter; Rotter, R.P.; Cammarano, D.; Brisson, N.; Basso, B.; Martre, P.; Aggarwal, P.K.; Angulo, C.; Bertuzzi, P.; Biernath, C.; Challinor, AJ; Doltra, J.; Gayler, S.; Goldberg, R.; Grant, Robert; Heng, L.; Hooker, J.; Hunt, L.A.; Ingwersen, J.; Izaurralde, Roberto C.; Kersebaum, K.C.; Mueller, C.; Naresh Kumar, S.; Nendel, C.; O'Leary, G.O.; Olesen, JE; Osborne, T.; Palosuo, T.; Priesack, E.; Ripoche, D.; Semenov, M.A.; Shcherbak, I.; Steduto, P.; Stockle, Claudio O.; Stratonovitch, P.; Streck, T.; Supit, I.; Tao, F.; Travasso, M.; Waha, K.; Wallach, D.; White, J.W.; Williams, J.R.; Wolf, J.

    2013-09-01T23:59:59.000Z

    Anticipating the impacts of climate change on crop yields is critical for assessing future food security. Process-based crop simulation models are the most commonly used tools in such assessments1,2. Analysis of uncertainties in future greenhouse gas emissions and their impacts on future climate change has been increasingly described in the literature3,4 while assessments of the uncertainty in crop responses to climate change are very rare. Systematic and objective comparisons across impact studies is difficult, and thus has not been fully realized5. Here we present the largest coordinated and standardized crop model intercomparison for climate change impacts on wheat production to date. We found that several individual crop models are able to reproduce measured grain yields under current diverse environments, particularly if sufficient details are provided to execute them. However, simulated climate change impacts can vary across models due to differences in model structures and algorithms. The crop-model component of uncertainty in climate change impact assessments was considerably larger than the climate-model component from Global Climate Models (GCMs). Model responses to high temperatures and temperature-by-CO2 interactions are identified as major sources of simulated impact uncertainties. Significant reductions in impact uncertainties through model improvements in these areas and improved quantification of uncertainty through multi-model ensembles are urgently needed for a more reliable translation of climate change scenarios into agricultural impacts in order to develop adaptation strategies and aid policymaking.

  8. Terrestrial biogeochemistry in the community climate system model (CCSM)

    E-Print Network [OSTI]

    Hoffman, Forrest M.

    Project (C4 MIP) Phase 1 experiments. In addition, CASA is one of three models--in addition to CN, and sea ice linked through a coupler that exchanges mass and energy fluxes and state information among, 5], the Community Sea Ice Model Version 5 (CSIM5) [6], and the Parallel Ocean Program Version 1

  9. Sensitivity of Remote Aerosol Distributions to Representation of Cloud-Aerosol Interactions in a Global Climate Model

    SciTech Connect (OSTI)

    Wang, Hailong; Easter, Richard C.; Rasch, Philip J.; Wang, Minghuai; Liu, Xiaohong; Ghan, Steven J.; Qian, Yun; Yoon, Jin-Ho; Ma, Po-Lun; Vinoj, V.

    2013-06-05T23:59:59.000Z

    Many global aerosol and climate models, including the widely used Community Atmosphere Model version 5 (CAM5), have large biases in predicting aerosols in remote regions such as upper troposphere and high latitudes. In this study, we conduct CAM5 sensitivity simulations to understand the role of key processes associated with aerosol transformation and wet removal affecting the vertical and horizontal long-range transport of aerosols to the remote regions. Improvements are made to processes that are currently not well represented in CAM5, which are guided by surface and aircraft measurements together with results from a multi-scale aerosol-climate model (PNNL-MMF) that explicitly represents convection and aerosol-cloud interactions at cloud-resolving scales. We pay particular attention to black carbon (BC) due to its importance in the Earth system and the availability of measurements. We introduce into CAM5 a new unified scheme for convective transport and aerosol wet removal with explicit aerosol activation above convective cloud base. This new implementation reduces the excessive BC aloft to better simulate observed BC profiles that show decreasing mixing ratios in the mid- to upper-troposphere. After implementing this new unified convective scheme, we examine wet removal of submicron aerosols that occurs primarily through cloud processes. The wet removal depends strongly on the sub-grid scale liquid cloud fraction and the rate of conversion of liquid water to precipitation. These processes lead to very strong wet removal of BC and other aerosols over mid- to high latitudes during winter months. With our improvements, the Arctic BC burden has a10-fold (5-fold) increase in the winter (summer) months, resulting in a much better simulation of the BC seasonal cycle as well. Arctic sulphate and other aerosol species also increase but to a lesser extent. An explicit treatment of BC aging with slower aging assumptions produces an additional 30-fold (5-fold) increase in the Arctic winter (summer) BC burden. This BC aging treatment, however, has minimal effect on other under-predicted species. Interestingly, our modifications to CAM5 that aim at improving prediction of high-latitude and upper tropospheric aerosols also produce much better AOD and AAOD over various other regions globally when compared to multi-year AERONET retrievals. The improved aerosol distributions have impacts on other aspects of CAM5, improving the simulation of global mean liquid water path and cloud forcing.

  10. Community Climate System Model (CCSM) Experiments and Output Data

    DOE Data Explorer [Office of Scientific and Technical Information (OSTI)]

    The CCSM web makes the source code of various versions of the model freely available and provides access to experiments that have been run and the resulting output data.

  11. Studies of climate variability in a simple coupled model

    E-Print Network [OSTI]

    Abiven, Claude

    2007-01-01T23:59:59.000Z

    The mechanisms of variability of a coupled atmosphere-ocean model are investigated through the study of two coupled configurations: an aquaplanet in which gyres are absent, and an aquaplanet in which a ridge extending from ...

  12. The effects of small perturbations in climate models

    E-Print Network [OSTI]

    Bell, Robert Eugene

    1991-01-01T23:59:59.000Z

    An energy balance model . II. 2 Equilibrium statistics 5 12 III A GENERAL CIRCULATION MODEL . . III. 1 Terra Blimda . III. 2 Equilibrium statistics 15 18 IV THE EFFECTS OF SMALL PERTURBATIONS . . 21 IV. 1 Response to a, Dirac delta, function IV. 2... standard deviations from the mean. , Relaxation time for different modes as a function of Legendre index n (North and Cahalan, 1981). 13 Illustration of a, rhomboidal truncation at degree 5 (R5). 17 The global mean surface temperature of Terra Blanda...

  13. Detecting vegetation-precipitation feedbacks in mid-Holocene North Africa from two climate models

    SciTech Connect (OSTI)

    Wang, Yi; Notaro, Michael; Liu, Zhengyu; Gallimore, Robert; Levis, Samuel; Kutzbach, John E.

    2008-03-31T23:59:59.000Z

    Using two climate-vegetation model simulations from the Fast Ocean Atmosphere Model (FOAM) and the Community Climate System Model (CCSM, version 2), we investigate vegetation-precipitation feedbacks across North Africa during the mid-Holocene. From mid-Holocene snapshot runs of FOAM and CCSM2, we detect a negative feedback at the annual timescale with our statistical analysis. Using the Monte- Carlo bootstrap method, the annual negative feedback is further confirmed to be significant in both simulations. Additional analysis shows that this negative interaction is partially caused by the competition between evaporation and transpiration in North African grasslands. Furthermore, we find the feedbacks decrease with increasing timescales, and change signs from positive to negative at increasing timescales in FOAM. The proposed mechanism for this sign switch is associated with the different persistent timescales of upper and lower soil water contents, and their interactions with vegetation and atmospheric precipitation.

  14. Modeled Interactive Effects of Precipitation, temperature, and [CO2] on Ecosystem Carbon and Water Dynamics in Different Climatic Zones

    SciTech Connect (OSTI)

    Luo, Yiqi [University of Oklahoma; Gerten, Dieter [Potsdam Institute for Climate Impact Research, Potsdam, Germany; Le Maire, Guerric [Laboratoire des Sciences du Climat et de l'Environement, France; Parton, William [University of Colorado, Fort Collins; Weng, Ensheng [University of Oklahoma, Norman; Zhou, Xuhuui [University of Oklahoma; Keough, Cindy [University of Colorado, Fort Collins; Beier, Claus [Riso National Laboratory, Roskilde, Denmark; Ciais, Philippe [Laboratoire des Sciences du Climat et de l'Environement, France; Cramer, Wolfgang [Potsdam Institute for Climate Impact Research, Potsdam, Germany; Dukes, Jeff [University of Massachusetts, Boston; Emmett, Bridget [Centre for Ecology and Hydrology, Bangor, Gwynedd, United Kingdom; Hanson, Paul J [ORNL; Knapp, Alan [Colorado State University, Fort Collins; Linder, Sune [Swedish University of Agricultural Sciences, Upsalla, Sweden; Nepstad, Daniel [Woods Hole Oceanographic Institution (WHOI), Woods Hole, MA; Rustad, Lindsey [USDA Forest Service

    2008-01-01T23:59:59.000Z

    Interactive effects of multiple global change factors on ecosystem processes are complex. It is relatively expensive to explore those interactions in manipulative experiments. We conducted a modeling analysis to identify potentially important interactions and to stimulate hypothesis formulation for experimental research. Four models were used to quantify interactive effects of climate warming (T), altered precipitation amounts [doubled (DP) and halved (HP)] and seasonality (SP, moving precipitation in July and August to January and February to create summer drought), and elevated [CO2] (C) on net primary production (NPP), heterotrophic respiration (Rh), net ecosystem production (NEP), transpiration, and runoff.We examined those responses in seven ecosystems, including forests, grasslands, and heathlands in different climate zones. The modeling analysis showed that none of the threeway interactions among T, C, and altered precipitation was substantial for either carbon or water processes, nor consistent among the seven ecosystems. However, two-way interactive effects on NPP, Rh, and NEP were generally positive (i.e. amplification of one factor s effect by the other factor) between T and C or between T and DP. A negative interaction (i.e. depression of one factor s effect by the other factor) occurred for simulated NPP between T and HP. The interactive effects on runoff were positive between T and HP. Four pairs of two-way interactive effects on plant transpiration were positive and two pairs negative. In addition, wet sites generally had smaller relative changes in NPP, Rh, runoff, and transpiration but larger absolute changes in NEP than dry sites in response to the treatments. The modeling results suggest new hypotheses to be tested in multifactor global change experiments. Likewise, more experimental evidence is needed for the further improvement of ecosystem models in order to adequately simulate complex interactive processes.

  15. Baseline for Climate Change: Modeling Watershed Aquatic Biodiversity Relative to Environmental and Anthropogenic Factors

    SciTech Connect (OSTI)

    Maurakis, Eugene G

    2010-10-01T23:59:59.000Z

    Objectives of the two-year study were to (1) establish baselines for fish and macroinvertebrate community structures in two mid-Atlantic lower Piedmont watersheds (Quantico Creek, a pristine forest watershed; and Cameron Run, an urban watershed, Virginia) that can be used to monitor changes relative to the impacts related to climate change in the future; (2) create mathematical expressions to model fish species richness and diversity, and macroinvertebrate taxa and macroinvertebrate functional feeding group taxa richness and diversity that can serve as a baseline for future comparisons in these and other watersheds in the mid-Atlantic region; and (3) heighten people’s awareness, knowledge and understanding of climate change and impacts on watersheds in a laboratory experience and interactive exhibits, through internship opportunities for undergraduate and graduate students, a week-long teacher workshop, and a website about climate change and watersheds. Mathematical expressions modeled fish and macroinvertebrate richness and diversity accurately well during most of the six thermal seasons where sample sizes were robust. Additionally, hydrologic models provide the basis for estimating flows under varying meteorological conditions and landscape changes. Continuations of long-term studies are requisite for accurately teasing local human influences (e.g. urbanization and watershed alteration) from global anthropogenic impacts (e.g. climate change) on watersheds. Effective and skillful translations (e.g. annual potential exposure of 750,000 people to our inquiry-based laboratory activities and interactive exhibits in Virginia) of results of scientific investigations are valuable ways of communicating information to the general public to enhance their understanding of climate change and its effects in watersheds.

  16. Atmospheric Horizontal Resolution Affects Tropical Climate Variability in Coupled Models

    E-Print Network [OSTI]

    Guilyardi, Eric

    di Geofisica e Vulcanologia, Bologna, Italy S. BEHERA, J.-J. LUO, AND S. MASSON Frontier Research model, SINTEX-Frontier (SINTEX-F), developed jointly at Istituto Nazionale di Geofisica e Vulcanologia that the Corresponding author address: A. Navarra, Istituto Nazionale di Geofisica e Vulcanologia, Via Donato Creti 12

  17. Modeling U.S. water resources under climate change*

    E-Print Network [OSTI]

    in natural systems and runoff, and future scenarios of water demand for power plant cooling are consistent's Future, 2(4): 197­244 (doi: 10.1002/2013EF000214) © 2014 with kind permission from the authors. Reprint-driven, the Program uses extensive Earth system and economic data and models to produce quantitative analysis

  18. Chemistryclimate model simulations of twenty-first century stratospheric climate

    E-Print Network [OSTI]

    Wirosoetisno, Djoko

    recovery causes a warming of the Southern Hemisphere polar lower stratosphere in summer with enhanced to an overall global cooling of the stratosphere in the simulations (0.59 6 0.07 K decade21 at 10 hPa), ozone cooling above. The rate of warming correlates with the rate of ozone recovery projected by the models and

  19. Changing Climates 

    E-Print Network [OSTI]

    Wythe, Kathy

    2008-01-01T23:59:59.000Z

    and a wide range of academic areas are investigating the different compo- nents. More recently, they are taking information gleaned from the global climate models and applying them to research questions pertaining to Texas. Dr. Bruce Mc...Carl, Regents Professor of agricultural economics at Texas A&M University, has researched the economics of climate change for the last 20 years. McCarl, as a lead CHANGING CLIMATES tx H2O | pg. McCarl ] tx H2O | pg. 4 Changing Climates author...

  20. programs in climate change

    E-Print Network [OSTI]

    existing programs in climate change science and infrastructure. The Laboratory has a 15- year history in climate change science. The Climate, Ocean and Sea Ice Modeling (COSIM) project develops and maintains advanced numerical models of the ocean, sea ice, and ice sheets for use in global climate change

  1. Transforming the representation of the boundary layer and low clouds for high-resolution regional climate modeling: Final report

    SciTech Connect (OSTI)

    Huang, Hsin-Yuan; Hall, Alex

    2013-07-24T23:59:59.000Z

    Stratocumulus and shallow cumulus clouds in subtropical oceanic regions (e.g., Southeast Pacific) cover thousands of square kilometers and play a key role in regulating global climate (e.g., Klein and Hartmann, 1993). Numerical modeling is an essential tool to study these clouds in regional and global systems, but the current generation of climate and weather models has difficulties in representing them in a realistic way (e.g., Siebesma et al., 2004; Stevens et al., 2007; Teixeira et al., 2011). While numerical models resolve the large-scale flow, subgrid-scale parameterizations are needed to estimate small-scale properties (e.g. boundary layer turbulence and convection, clouds, radiation), which have significant influence on the resolved scale due to the complex nonlinear nature of the atmosphere. To represent the contribution of these fine-scale processes to the resolved scale, climate models use various parameterizations, which are the main pieces in the model that contribute to the low clouds dynamics and therefore are the major sources of errors or approximations in their representation. In this project, we aim to 1) improve our understanding of the physical processes in thermal circulation and cloud formation, 2) examine the performance and sensitivity of various parameterizations in the regional weather model (Weather Research and Forecasting model; WRF), and 3) develop, implement, and evaluate the advanced boundary layer parameterization in the regional model to better represent stratocumulus, shallow cumulus, and their transition. Thus, this project includes three major corresponding studies. We find that the mean diurnal cycle is sensitive to model domain in ways that reveal the existence of different contributions originating from the Southeast Pacific land-masses. The experiments suggest that diurnal variations in circulations and thermal structures over this region are influenced by convection over the Peruvian sector of the Andes cordillera, while the mostly dry mountain-breeze circulations force an additional component that results in semi-diurnal variations near the coast. A series of numerical tests, however, reveal sensitivity of the simulations to the choice of vertical grid, limiting the possibility of solid quantitative statements on the amplitudes and phases of the diurnal and semidiurnal components across the domain. According to our experiments, the Mellor-Yamada-Nakanishi-Niino (MYNN) boundary layer scheme and the WSM6 microphysics scheme is the combination of schemes that performs best. For that combination, mean cloud cover, liquid water path, and cloud depth are fairly wellsimulated, while mean cloud top height remains too low in comparison to observations. Both microphysics and boundary layer schemes contribute to the spread in liquid water path and cloud depth, although the microphysics contribution is slightly more prominent. Boundary layer schemes are the primary contributors to cloud top height, degree of adiabaticity, and cloud cover. Cloud top height is closely related to surface fluxes and boundary layer structure. Thus, our study infers that an appropriate tuning of cloud top height would likely improve the low-cloud representation in the model. Finally, we show that entrainment governs the degree of adiabaticity, while boundary layer decoupling is a control on cloud cover. In the intercomparison study using WRF single-column model experiments, most parameterizations show a poor agreement of the vertical boundary layer structure when compared with large-eddy simulation models. We also implement a new Total-Energy/Mass- Flux boundary layer scheme into the WRF model and evaluate its ability to simulate both stratocumulus and shallow cumulus clouds. Result comparisons against large-eddy simulation show that this advanced parameterization based on the new Eddy-Diffusivity/Mass-Flux approach provides a better performance than other boundary layer parameterizations.

  2. Modeling of Oceanic Gas Hydrate Instability and Methane Release in Response to Climate Change

    SciTech Connect (OSTI)

    Reagan, Matthew; Reagan, Matthew T.; Moridis, George J.

    2008-04-15T23:59:59.000Z

    Paleooceanographic evidence has been used to postulate that methane from oceanic hydrates may have had a significant role in regulating global climate, implicating global oceanic deposits of methane gas hydrate as the main culprit in instances of rapid climate change that have occurred in the past. However, the behavior of contemporary oceanic methane hydrate deposits subjected to rapid temperature changes, like those predicted under future climate change scenarios, is poorly understood. To determine the fate of the carbon stored in these hydrates, we performed simulations of oceanic gas hydrate accumulations subjected to temperature changes at the seafloor and assessed the potential for methane release into the ocean. Our modeling analysis considered the properties of benthic sediments, the saturation and distribution of the hydrates, the ocean depth, the initial seafloor temperature, and for the first time, estimated the effect of benthic biogeochemical activity. The results show that shallow deposits--such as those found in arctic regions or in the Gulf of Mexico--can undergo rapid dissociation and produce significant methane fluxes of 2 to 13 mol/yr/m{sup 2} over a period of decades, and release up to 1,100 mol of methane per m{sup 2} of seafloor in a century. These fluxes may exceed the ability of the seafloor environment (via anaerobic oxidation of methane) to consume the released methane or sequester the carbon. These results will provide a source term to regional or global climate models in order to assess the coupling of gas hydrate deposits to changes in the global climate.

  3. 3D climate modeling of Earth-like extrasolar planets orbiting different types of host stars

    E-Print Network [OSTI]

    Godolt, M; Hamann-Reinus, A; Kitzmann, D; Kunze, M; Langematz, U; von Paris, P; Patzer, A B C; Rauer, H; Stracke, B

    2015-01-01T23:59:59.000Z

    The potential habitability of a terrestrial planet is usually defined by the possible existence of liquid water on its surface. The potential presence of liquid water depends on many factors such as, most importantly, surface temperatures. The properties of the planetary atmosphere and its interaction with the radiative energy provided by the planet's host star are thereby of decisive importance. In this study we investigate the influence of different main-sequence stars upon the climate of Earth-like extrasolar planets and their potential habitability by applying a 3D Earth climate model accounting for local and dynamical processes. The calculations have been performed for planets with Earth-like atmospheres at orbital distances where the total amount of energy received from the various host stars equals the solar constant. In contrast to previous 3D modeling studies, we include the effect of ozone radiative heating upon the vertical temperature structure of the atmospheres. The global orbital mean results o...

  4. An improved lake model for climate simulations: Model structure, evaluation, and sensitivity analyses in CESM1

    E-Print Network [OSTI]

    Subin, Z.M.

    2013-01-01T23:59:59.000Z

    of the heat capacity of the ice mass and liquid water mass.all the ice (liquid) is melted (frozen). Heat capacities are

  5. Development of a High-Performance Office Building Simulation Model for a Hot and Humid Climate

    E-Print Network [OSTI]

    Cho, S.; Haberl, J.

    -performance measures applicable to office buildings in hot and humid climates and to develop a high-performance (maximum energy-efficient) building model that only uses technologies readily available in the contemporary market. The high-performance model showed... requirements. This base-case model consumed a total of 7,721 GJ/yr. As shown in Figure 22, the implementation of occupancy sensors impacted the energy consumption the most, saving 11.2% of the total energy consumption. By this measure, indoor lights were...

  6. Detection of greenhouse-gas-induced climatic change

    SciTech Connect (OSTI)

    Wigley, T.M.L.; Jones, P.D.

    1992-07-15T23:59:59.000Z

    The aims of the US Department of Energy's Carbon Dioxide Research Program are to improve assessments of greenhouse-gas-induced climatic change and to define and reduce uncertainties through selected research. This project will address: The regional and seasonal details of the expected climatic changes; how rapidly will these changes occur; how and when will the climatic effects of CO[sub 2] and other greenhouse gases be first detected; and the relationships between greenhouse-gas-induced climatic change and changes caused by other external and internal factors. The present project addresses all of these questions. Many of the diverse facets of greenhouse-gas-related climate research can be grouped under three interlinked subject areas: modeling, first detection and supporting data. This project will include the analysis of climate forcing factors, the development and refinement of transient response climate models, and the use of instrumental data in validating General Circulation Models (GCMs).

  7. Validation of Climate Models The CliMaTiC sysTeM is constituted by four inti-

    E-Print Network [OSTI]

    Lucarini, Valerio

    of macroscopic driving and modulating agents, such as solar heating, Earth's rotation, and gravitation Panel on Climate Change (IPCC4AR) are unprecedented. The validation or auditing--overall evaluation

  8. Improving Comfort in Hot-Humid Climates with a Whole-House Dehumidifier, Windermere, Florida (Fact Sheet)

    SciTech Connect (OSTI)

    Not Available

    2013-11-01T23:59:59.000Z

    Maintaining comfort in a home can be challenging in hot-humid climates. At the common summer temperature set point of 75 degrees F, the perceived air temperature can vary by 11 degrees F because higher indoor humidity reduces comfort. Often the air conditioner (AC) thermostat set point is lower than the desirable cooling level to try to increase moisture removal so that the interior air is not humid or "muggy." However, this method is not always effective in maintaining indoor relative humidity (RH) or comfort. In order to quantify the performance of a combined whole-house dehumidifier (WHD) AC system, researchers from the U.S. Department of Energy's Building America team Consortium of Advanced Residential Buildings (CARB) monitored the operation of two Lennox AC systems coupled with a Honeywell DH150 TrueDRY whole-house dehumidifier for a six-month period. By using a WHD to control moisture levels (latent cooling) and optimizing a central AC to control temperature (sensible cooling), improvements in comfort can be achieved while reducing utility costs. Indoor comfort for this study was defined as maintaining indoor conditions at below 60% RH and a humidity ratio of 0.012 lbm/lbm while at common dry bulb set point temperatures of 74 degrees -80 degrees F. In addition to enhanced comfort, controlling moisture to these levels can reduce the risk of other potential issues such as mold growth, pests, and building component degradation. Because a standard AC must also reduce dry bulb air temperature in order to remove moisture, a WHD is typically needed to support these latent loads when sensible heat removal is not desired.

  9. An Improved Probabilistic Fracture Mechanics Model for Pressurized Thermal Shock

    SciTech Connect (OSTI)

    Dickson, T.L.

    2001-10-29T23:59:59.000Z

    This paper provides an overview of an improved probabilistic fracture mechanics (PFM) model used for calculating the conditional probabilities of fracture and failure of a reactor pressure vessel (RPV) subjected to pressurized-thermal-shock (PTS) transients. The updated PFM model incorporates several new features: expanded databases for the fracture toughness properties of RPV steels; statistical representations of the fracture toughness databases developed through application of rigorous mathematical procedures; and capability of generating probability distributions for RPV fracture and failure. The updated PFM model was implemented into the FAVOR fracture mechanics program, developed at Oak Ridge National Laboratory as an applications tool for RPV integrity assessment; an example application of that implementation is discussed herein. Applications of the new PFM model are providing essential input to a probabilistic risk assessment (PRA) process that will establish an improved technical basis for re-assessment of current PTS regulations by the US Nuclear Regulatory Commission (NRC). The methodology described herein should be considered preliminary and subject to revision in the PTS re-evaluation process.

  10. Voronoi Tessellations and Their Application to Climate and Global Modeling

    SciTech Connect (OSTI)

    Ju, Lili [University of South Carolina; Ringler, Todd [Los Alamos National Laboratory; Gunzburger, Max [Florida State University

    2011-01-01T23:59:59.000Z

    We review the use of Voronoi tessellations for grid generation, especially on the whole sphere or in regions on the sphere. Voronoi tessellations and the corresponding Delaunay tessellations in regions and surfaces on Euclidean space are defined and properties they possess that make them well-suited for grid generation purposes are discussed, as are algorithms for their construction. This is followed by a more detailed look at one very special type of Voronoi tessellation, the centroidal Voronoi tessellation (CVT). After defining them, discussing some of their properties, and presenting algorithms for their construction, we illustrate the use of CVTs for producing both quasi-uniform and variable resolution meshes in the plane and on the sphere. Finally, we briefly discuss the computational solution of model equations based on CVTs on the sphere.

  11. Tropical precipitation simulated by the NCAR Community Climate Model (CCM3): an evaluation based on TRMM satellite measurements 

    E-Print Network [OSTI]

    Collier, Jonathan Craig

    2005-11-01T23:59:59.000Z

    This study evaluates the simulation of tropical precipitation by the Community Climate Model, Version 3, developed at the National Center for Atmospheric Research. For an evaluation of the annual cycle of precipitation, ...

  12. Modelling of mineral dust for interglacial and glacial climate conditions with a focus on Antarctica

    SciTech Connect (OSTI)

    Sudarchikova, Natalia; Mikolajewicz, Uwe; Timmreck, C.; O'Donnell, D.; Schurgers, G.; Sein, Dmitry; Zhang, Kai

    2015-01-01T23:59:59.000Z

    Mineral dust cycle responds to insolation-induced climate change and plays an important role in the climate system by affecting the radiative balance of the atmosphere. Polar ice cores provide unique information about deposition of aeolian dust particles in the past which indicates climate variability. In the current study the dust cycle in different climate conditions simulated by ECHAM5-HAM is analyzed. The study is focused on the Southern Hemisphere with emphasis on the Antarctic region. The investigated periods include four interglacial time-slices: the pre-industrial control (CTRL), mid-Holocene (6,000 years BP), Eemian (126,000 years BP), last glacial inception (115,000 years BP) and one glacial time interval: Last Glacial Maximum (LGM) (21,000 years BP). This study is a first attempt to simulate past interglacial dust cycles and to understand the quantitative contribution of different processes, such as emission, atmospheric transport and precipitation to the total dust deposition in Antarctica. Results suggest increased deposition of mineral dust globally and in Antarctica in the past interglacial periods relative to the preindustrial CTRL simulation. Maximum dust deposition in Antarctica was simulated for the glacial period. One of the major factors responsible for the increase of dust deposition in the mid-Holocene and Eemian is enhanced Southern Hemisphere dust emissions. The moderate change of dust deposition in Antarctica in the last glacial inception period is caused by the slightly stronger poleward atmospheric transport efficiency compared to the pre-industrial. In the LGM simulation, dust deposition over Antarctica is substantially increased due to 2.6 times higher Southern Hemisphere dust emissions, 2 times stronger atmospheric transport towards Antarctica, and 30% weaker precipitation over the Southern Ocean. The model is able to reproduce the order of magnitude of dust deposition globally and in Antarctica for the pre-industrial and LGM climate. However more records are needed to validate simulated dust deposition for the past interglacial time-slices.

  13. Evaluating Clouds, Aerosols, and their Interactions in Three Global Climate Models using COSP and Satellite Observations

    SciTech Connect (OSTI)

    Ban-Weiss, George; Jin, Ling; Bauer, S.; Bennartz, Ralph; Liu, Xiaohong; Zhang, Kai; Ming, Yi; Guo, Huan; Jiang, Jonathan

    2014-09-23T23:59:59.000Z

    Accurately representing aerosol-cloud interactions in global climate models is challenging. As parameterizations evolve, it is important to evaluate their performance with appropriate use of observations. In this work we compare aerosols, clouds, and their interactions in three climate models (AM3, CAM5, ModelE) to MODIS satellite observations. Modeled cloud properties were diagnosed using the CFMIP Observations Simulator Package (COSP). Cloud droplet number concentrations (N) were derived using the same algorithm for both satellite-simulated model values and observations. We find that aerosol optical depth tau simulated by models is similar to observations. For N, AM3 and CAM5 capture the observed spatial pattern of higher values in near-coast versus remote ocean regions, though modeled values in general are higher than observed. In contrast, ModelE simulates lower N in most near-coast versus remote regions. Aerosol- cloud interactions were computed as the sensitivity of N to tau for marine liquid clouds off the coasts of South Africa and Eastern Asia where aerosol pollution varies in time. AM3 and CAM5 are in most cases more sensitive than observations, while the sensitivity for ModelE is statistically insignificant. This widely used sensitivity could be subject to misinterpretation due to the confounding influence of meteorology on both aerosols and clouds. A simple framework for assessing the N – tau sensitivity at constant meteorology illustrates that observed sensitivity can change from positive to statistically insignificant when including the confounding influence of relative humidity. Satellite simulated values of N were compared to standard model output and found to be higher with a bias of 83 cm-3.

  14. Recovery Boiler Modeling: An Improved Char Burning Model Including Sulfate Reduction and Carbon Removal 

    E-Print Network [OSTI]

    Grace, T. M.; Wag, K. J.; Horton, R. R.; Frederick, W. J.

    1994-01-01T23:59:59.000Z

    This paper describes an improved model of char burning during black liquor combustion that is capable of predicting net rates of sulfate reduction to sulfide as well as carbon burnup rates. Enhancements include a proper ...

  15. Super Models, Old King Coal II, & Civil Disobedience For fellow technocrats: "Climate simulations for 1880-2003 with GISS modelE", to appear soon

    E-Print Network [OSTI]

    Hansen, James E.

    Super Models, Old King Coal II, & Civil Disobedience Model: For fellow technocrats: "Climate" was a guise, using prurient interest to gain attention. Sorry! "Old King Coal II" and "Civil Disobedience" are accurate headings. Old King Coal II: Thanks for comments/suggestions re my "Old King Coal" e-mail. Main

  16. Sandia National Laboratories: Climate/Environment

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    ClimateEnvironment ClimateEnvironment On January 27, 2011, in ClimateEnvironment Sensing and Monitoring Modeling and Analysis Carbon Management Water & Environment Publications...

  17. Regional climate effects of irrigation and urbanization in thewestern united states: a model intercomparison

    SciTech Connect (OSTI)

    Snyder, M.A.; Kueppers, L.M.; Sloan, L.C.; Cavan, D.C.; Jin, J.; Kanamaru, H.; Miller, N.L.; Tyree, M.; Du, H.; Weare, B.

    2006-05-01T23:59:59.000Z

    In the western United States, more than 30,500 square miles has been converted to irrigated agriculture and urban areas. This study compares the climate responses of four regional climate models (RCMs) to these past land-use changes. The RCMs used two contrasting land cover distributions: potential natural vegetation, and modern land cover that includes agriculture and urban areas. Three of the RCMs represented irrigation by supplementing soil moisture, producing large decreases in August mean (-2.5 F to -5.6 F) and maximum (-5.2 F to -10.1 F) 2-meter temperatures where natural vegetation was converted to irrigated agriculture. Conversion to irrigated agriculture also resulted in large increases in relative humidity (9 percent 36 percent absolute change). Only one of the RCMs produced increases in summer minimum temperature. Converting natural vegetation to urban land cover produced modest but discernable climate effects in all models, with the magnitude of the effects dependent upon the preexisting vegetation type. Overall, the RCM results indicate that land use change impacts are most pronounced during the summer months, when surface heating is strongest and differences in surface moisture between irrigated land and natural vegetation are largest. The irrigation effect on summer maximum temperatures is comparable in magnitude (but opposite in sign) to predicted future temperature change due to increasing greenhouse gas concentrations.

  18. NEW WORK AND STUDY OPPORTUNITIES IN CLIMATE CHANGE Climate System Analysis Group (CSAG)

    E-Print Network [OSTI]

    Cohen, Ronald C.

    . - Postdoc: Climate modeling - Postdoc: Climate change information communication and dissemination - Research Associate: Climate change information communication and dissemination - PhD: Climate change information communication and dissemination - MSc/PhD: Physical science of climate change What to expect: Successful

  19. Improved crystallographic models through iterated local density-guided model deformation and reciprocal-space refinement

    SciTech Connect (OSTI)

    Terwilliger, Thomas C., E-mail: terwilliger@lanl.gov [Los Alamos National Laboratory, Los Alamos, NM 87545 (United States); Read, Randy J. [University of Cambridge, Cambridge CB2 0XY (United Kingdom); Adams, Paul D. [Lawrence Berkeley National Laboratory, One Cyclotron Road, Building 64R0121, Berkeley, CA 94720 (United States); Brunger, Axel T. [Stanford University, 318 Campus Drive West, Stanford, CA 94305-5432 (United States); Afonine, Pavel V.; Grosse-Kunstleve, Ralf W. [Lawrence Berkeley National Laboratory, One Cyclotron Road, Building 64R0121, Berkeley, CA 94720 (United States); Hung, Li-Wei [Los Alamos National Laboratory, Los Alamos, NM 87545 (United States)

    2012-07-01T23:59:59.000Z

    A density-based procedure is described for improving a homology model that is locally accurate but differs globally. The model is deformed to match the map and refined, yielding an improved starting point for density modification and further model-building. An approach is presented for addressing the challenge of model rebuilding after molecular replacement in cases where the placed template is very different from the structure to be determined. The approach takes advantage of the observation that a template and target structure may have local structures that can be superimposed much more closely than can their complete structures. A density-guided procedure for deformation of a properly placed template is introduced. A shift in the coordinates of each residue in the structure is calculated based on optimizing the match of model density within a 6 Å radius of the center of that residue with a prime-and-switch electron-density map. The shifts are smoothed and applied to the atoms in each residue, leading to local deformation of the template that improves the match of map and model. The model is then refined to improve the geometry and the fit of model to the structure-factor data. A new map is then calculated and the process is repeated until convergence. The procedure can extend the routine applicability of automated molecular replacement, model building and refinement to search models with over 2 Å r.m.s.d. representing 65–100% of the structure.

  20. Improving Convection Parameterization Using ARM Observations and NCAR Community Atmosphere Model

    SciTech Connect (OSTI)

    Zhang, Guang J [Scripps Institution of Oceanography

    2013-07-29T23:59:59.000Z

    Highlight of Accomplishments: We made significant contribution to the ASR program in this funding cycle by better representing convective processes in GCMs based on knowledge gained from analysis of ARM/ASR observations. In addition, our work led to a much improved understanding of the interaction among aerosol, convection, clouds and climate in GCMs.

  1. A reduced-form statistical climate model suitable for coupling with economic emissions projections

    E-Print Network [OSTI]

    Rabin, Gregory S

    2007-01-01T23:59:59.000Z

    In this work, we use models based on past data and scientific analysis to determine possible future states of the environment. We attempt to improve the equations for temperature and greenhouse gas concentration used in ...

  2. DOE Workshop; Pan-Gass Conference on the Representation of Atmospheric Processes in Weather and Climate Models

    SciTech Connect (OSTI)

    Morrison, PI Hugh

    2012-09-21T23:59:59.000Z

    This is the first meeting of the whole new GEWEX (Global Energy and Water Cycle Experiment) Atmospheric System Study (GASS) project that has been formed from the merger of the GEWEX Cloud System Study (GCSS) Project and the GEWEX Atmospheric Boundary Layer Studies (GABLS). As such, this meeting will play a major role in energizing GEWEX work in the area of atmospheric parameterizations of clouds, convection, stable boundary layers, and aerosol-cloud interactions for the numerical models used for weather and climate projections at both global and regional scales. The representation of these processes in models is crucial to GEWEX goals of improved prediction of the energy and water cycles at both weather and climate timescales. This proposal seeks funds to be used to cover incidental and travel expenses for U.S.-based graduate students and early career scientists (i.e., within 5 years of receiving their highest degree). We anticipate using DOE funding to support 5-10 people. We will advertise the availability of these funds by providing a box to check for interested participants on the online workshop registration form. We will also send a note to our participants' mailing lists reminding them that the funds are available and asking senior scientists to encourage their more junior colleagues to participate. All meeting participants are encouraged to submit abstracts for oral or poster presentations. The science organizing committee (see below) will base funding decisions on the relevance and quality of these abstracts, with preference given to under-represented populations (especially women and minorities) and to early career scientists being actively mentored at the meeting (e.g. students or postdocs attending the meeting with their advisor).

  3. Seasonal cycle of Precipitation over Major River Basins in South and Southeast Asia: A Review of the CMIP5 climate models data for present climate and future climate projections

    E-Print Network [OSTI]

    Hasson, Shabeh ul; Lucarini, Valerio; Böhner, Jürgen

    2015-01-01T23:59:59.000Z

    We review the skill of thirty coupled climate models participating in Coupled Model Intercomparison Project 5 in terms of reproducing properties of the seasonal cycle of precipitation over the major river basins of South and Southeast Asia (Indus, Ganges, Brahmaputra and Mekong) for historical period (1961-2000). We also present projected changes by these models by end of century (2061-2100) under extreme scenario RCP8.5. First, we assess their ability to reproduce observed timings of the monsoon onset and the rate of rapid fractional accumulation (RFA slope) - a measure of seasonality within active monsoon period. Secondly, we apply a threshold-independent seasonality index (SI) - a multiplicative measure of precipitation and extent of its concentration relative to the uniform distribution (relative entropy - RE). We apply SI distinctly for monsoonal precipitation regime (MPR), westerly precipitation regime (WPR) and annual precipitation regime. For present climate, neither any single model nor the multi-mod...

  4. Development and evaluation of a convection scheme for use in climate models

    SciTech Connect (OSTI)

    Emanuel, K.A. [Massachusetts Inst. of Tech., Cambridge, MA (United States). Program for Atmospheres, Oceans, and Climate] [Massachusetts Inst. of Tech., Cambridge, MA (United States). Program for Atmospheres, Oceans, and Climate; Zivkovic-Rothman, M. [Atmospheric and Environmental Research, Inc., Cambridge, MA (United States)] [Atmospheric and Environmental Research, Inc., Cambridge, MA (United States)

    1999-06-01T23:59:59.000Z

    Cumulus convection is a key process in controlling the water vapor content of the atmosphere, which is in turn the largest feedback mechanism for climate change in global climate models. Yet scant attention has been paid to designing convective representations that attempt to handle water vapor with fidelity, and even less to evaluating their performance. Here the authors attempt to address this deficiency by designing a representation of cumulus convection with close attention paid to convective water fluxes and by subjecting the scheme to rigorous tests using sounding array data. The authors maintain that such tests, in which a single-column model is forced by large-scale processes measured by or inferred from the sounding data, must be carried out over a period at least as long as the radiative-subsidence timescale--about 30 days--governing the water vapor adjustment time. The authors also argue that the observed forcing must be preconditioned to guarantee integral enthalpy conservation, else errors in the single-column prediction may be falsely attributed to convective schemes. Optimization of the new scheme`s parameters is performed using one month of data from the intensive flux array operating during the Tropical Ocean Global Atmosphere Coupled Ocean-Atmosphere Response Experiment, with the aid of the adjoint of the linear tangent of the single-column model. Residual root-mean-square errors, after optimization, are about 15% in relative humidity and .8 K in temperature. It is difficult to reject the hypothesis that the residual errors are due to noise in the forcing. Evaluation of the convective scheme is performed using Global Atmospheric Research Program Atlantic Tropical Experiment data. The performance of the scheme is compared to that of a few other schemes used in current climate models. It is also shown that a vertical resolution better than 50 mb in pressure is necessary for accurate prediction of atmospheric water vapor.

  5. Formation of algae growth constitutive relations for improved algae modeling.

    SciTech Connect (OSTI)

    Gharagozloo, Patricia E.; Drewry, Jessica L.

    2013-01-01T23:59:59.000Z

    This SAND report summarizes research conducted as a part of a two year Laboratory Directed Research and Development (LDRD) project to improve our abilities to model algal cultivation. Algae-based biofuels have generated much excitement due to their potentially large oil yield from relatively small land use and without interfering with the food or water supply. Algae mitigate atmospheric CO2 through metabolism. Efficient production of algal biofuels could reduce dependence on foreign oil by providing a domestic renewable energy source. Important factors controlling algal productivity include temperature, nutrient concentrations, salinity, pH, and the light-to-biomass conversion rate. Computational models allow for inexpensive predictions of algae growth kinetics in these non-ideal conditions for various bioreactor sizes and geometries without the need for multiple expensive measurement setups. However, these models need to be calibrated for each algal strain. In this work, we conduct a parametric study of key marine algae strains and apply the findings to a computational model.

  6. Aerosol, Cloud, and Climate: From Observation to Model (457th Brookhaven Lecture)

    SciTech Connect (OSTI)

    Wang, Jian (Ph.D., Environmental Sciences Department) [Ph.D., Environmental Sciences Department

    2010-05-12T23:59:59.000Z

    In the last 100 years, the Earth has warmed by about 1ºF, glaciers and sea ice have been melting more quickly than previously, especially during the past decade, and the level of the sea has risen about 6-8 inches worldwide. Scientists have long been investigating this phenomenon of “global warming,” which is believed to be at least partly due to the increased carbon dioxide (CO2) concentration in the air from burning fossil fuels. Funded by DOE, teams of researchers from BNL and other national labs have been gathering data in the U.S. and internationally to build computer models of climate and weather to help in understanding general patterns, causes, and perhaps, solutions. Among many findings, researchers observed that atmospheric aerosols, minute particles in the atmosphere, can significantly affect global energy balance and climate. Directly, aerosols scatter and absorb sunlight. Indirectly, increased aerosol concentration can lead to smaller cloud droplets, changing clouds in ways that tend to cool global climate and potentially mask overall warming from man-made CO2.

  7. Modeling the Summertime Climate of Southwest Asia: The Role of Land Surface Processes in Shaping the Climate of Semiarid Regions

    E-Print Network [OSTI]

    Marcella, Marc P.

    Presented is a study on the role of land surface processes in determining the summertime climate over the semiarid region of southwest Asia. In this region, a warm surface air temperature bias of 3.5°C is simulated in the ...

  8. The impact of centennial-scale solar forcing on the Holocene climate: simulations with a coupled climate model

    E-Print Network [OSTI]

    Renssen, Hans

    lasts about 50-year longer than the TSI anomaly. This is caused by extensive sea-ice build- up, which. During shorter TSI anomalies, such as event B centered at 2300 BP, sea-ice build-up is insufficientThe impact of centennial-scale solar forcing on the Holocene climate: simulations with a coupled

  9. Climate Past, Climate Present, Climate Future Douglas Nychka,

    E-Print Network [OSTI]

    Nychka, Douglas

    series and an energy balance model. 1000 1200 1400 1600 1800 2000 -1.5-1.0-0.50.00.5 Year Degree. Supported by US NSF 7th World Congress Prob. and Stat., Singapore July 2008 #12;What is climate? Climate will use statistics to talk about the "known un- knowns" for the Earth's climate Statistics uses

  10. Climate and Environmental Sciences Division Strategic Plan Water is a key component of the earth and human

    E-Print Network [OSTI]

    Wood, Robert

    , and subsurface processes, as well as climate and earth system modeling and integrated assessment modeling and plan the development of next- generation human-earth system models for improving long-term predictions

  11. IMPROVED NUMERICAL METHODS FOR MODELING RIVER-AQUIFER INTERACTION.

    SciTech Connect (OSTI)

    Tidwell, Vincent C.; Sue Tillery; Phillip King

    2008-09-01T23:59:59.000Z

    A new option for Local Time-Stepping (LTS) was developed to use in conjunction with the multiple-refined-area grid capability of the U.S. Geological Survey's (USGS) groundwater modeling program, MODFLOW-LGR (MF-LGR). The LTS option allows each local, refined-area grid to simulate multiple stress periods within each stress period of a coarser, regional grid. This option is an alternative to the current method of MF-LGR whereby the refined grids are required to have the same stress period and time-step structure as the coarse grid. The MF-LGR method for simulating multiple-refined grids essentially defines each grid as a complete model, then for each coarse grid time-step, iteratively runs each model until the head and flux changes at the interfacing boundaries of the models are less than some specified tolerances. Use of the LTS option is illustrated in two hypothetical test cases consisting of a dual well pumping system and a hydraulically connected stream-aquifer system, and one field application. Each of the hypothetical test cases was simulated with multiple scenarios including an LTS scenario, which combined a monthly stress period for a coarse grid model with a daily stress period for a refined grid model. The other scenarios simulated various combinations of grid spacing and temporal refinement using standard MODFLOW model constructs. The field application simulated an irrigated corridor along the Lower Rio Grande River in New Mexico, with refinement of a small agricultural area in the irrigated corridor.The results from the LTS scenarios for the hypothetical test cases closely replicated the results from the true scenarios in the refined areas of interest. The head errors of the LTS scenarios were much smaller than from the other scenarios in relation to the true solution, and the run times for the LTS models were three to six times faster than the true models for the dual well and stream-aquifer test cases, respectively. The results of the field application show that better estimates of daily stream leakage can be made with the LTS simulation, thereby improving the efficiency of daily operations for an agricultural irrigation system. ACKNOWLEDGEMENTSThe authors appreciatively acknowledge support for Sue Tillery provided by Sandia National Laboratories' through a Campus Executive Laboratory Directed Research and Development (LDRD) research project.Funding for this study was provided by Directed Research and Development (LDRD) research project.

  12. Tropical and subtropical cloud transitions in weather and climate prediction models: the GCSS/WGNE Pacific Cross-Section Intercomparison (GPCI)

    SciTech Connect (OSTI)

    Teixeira, J.; Cardoso, S.; Bonazzola, M.; Cole, Jason N.; DelGenio, Anthony D.; DeMott, C.; Franklin, A.; Hannay, Cecile; Jakob, Christian; Jiao, Y.; Karlsson, J.; Kitagawa, H.; Koehler, M.; Kuwano-Yoshida, A.; LeDrian, C.; Lock, Adrian; Miller, M.; Marquet, P.; Martins, J.; Mechoso, C. R.; Meijgaard, E. V.; Meinke, I.; Miranda, P.; Mironov, D.; Neggers, Roel; Pan, H. L.; Randall, David A.; Rasch, Philip J.; Rockel, B.; Rossow, William B.; Ritter, B.; Siebesma, A. P.; Soares, P.; Turk, F. J.; Vaillancourt, P.; Von Engeln, A.; Zhao, M.

    2011-11-01T23:59:59.000Z

    A model evaluation approach is proposed where weather and climate prediction models are analyzed along a Pacific Ocean cross-section, from the stratocumulus regions off the coast of California, across the shallow convection dominated trade-winds, to the deep convection regions of the ITCZ: the GCSS/WGNE Pacific Cross-section Intercomparison (GPCI). The main goal of GPCI is to evaluate, and help understand and improve the representation of tropical and sub-tropical cloud processes in weather and climate prediction models. In this paper, a detailed analysis of cloud regime transitions along the cross-section from the sub-tropics to the tropics for the season JJA of 1998 is presented. This GPCI study confirms many of the typical weather and climate prediction model problems in the representation of clouds: underestimation of clouds in the stratocumulus regime by most models with the corresponding consequences in terms of shortwave radiation biases; overestimation of clouds by the ECMWF Re-Analysis (ERA40) in the deep tropics (in particular) with the corresponding impact in the outgoing longwave radiation; large spread between the different models in terms of cloud cover, liquid water path and shortwave radiation; significant differences between the models in terms of vertical crosssections of cloud properties (in particular), vertical velocity and relative humidity. An alternative analysis of cloud cover mean statistics is proposed where sharp gradients in cloud cover along the GPCI transect are taken into account. This analysis shows that the negative cloud bias of some models and ERA40 in the stratocumulus regions (as compared to ISCCP) is associated not only with lower values of cloud cover in these regimes, but also with a stratocumulus-to-cumulus transition that occurs too early along the trade-wind Lagrangian trajectory. Histograms of cloud cover along the cross-section differ significantly between models. Some models exhibit a quasi-bimodal structure with cloud cover being either very large (close to 100%) or very small, while other models show a more continuous transition. The ISCCP observations suggest that reality is in-between these two extreme examples. These different patterns reflect the diverse nature of the cloud, boundary layer, and convection parameterizations in the participating weather and climate prediction models.

  13. Final Technical Report for "Collaborative Research: Regional climate-change projections through next-generation empirical and dynamical models"

    SciTech Connect (OSTI)

    Robertson, A.W.; Ghil, M.; Kravtsov, K.; Smyth, P.J.

    2011-04-08T23:59:59.000Z

    This project was a continuation of previous work under DOE CCPP funding in which we developed a twin approach of non-homogeneous hidden Markov models (NHMMs) and coupled ocean-atmosphere (O-A) intermediate-complexity models (ICMs) to identify the potentially predictable modes of climate variability, and to investigate their impacts on the regional-scale. We have developed a family of latent-variable NHMMs to simulate historical records of daily rainfall, and used them to downscale seasonal predictions. We have also developed empirical mode reduction (EMR) models for gaining insight into the underlying dynamics in observational data and general circulation model (GCM) simulations. Using coupled O-A ICMs, we have identified a new mechanism of interdecadal climate variability, involving the midlatitude oceans mesoscale eddy field and nonlinear, persistent atmospheric response to the oceanic anomalies. A related decadal mode is also identified, associated with the oceans thermohaline circulation. The goal of the continuation was to build on these ICM results and NHMM/EMR model developments and software to strengthen two key pillars of support for the development and application of climate models for climate change projections on time scales of decades to centuries, namely: (a) dynamical and theoretical understanding of decadal-to-interdecadal oscillations and their predictability; and (b) an interface from climate models to applications, in order to inform societal adaptation strategies to climate change at the regional scale, including model calibration, correction, downscaling and, most importantly, assessment and interpretation of spread and uncertainties in multi-model ensembles. Our main results from the grant consist of extensive further development of the hidden Markov models for rainfall simulation and downscaling specifically within the non-stationary climate change context together with the development of parallelized software; application of NHMMs to downscaling of rainfall projections over India; identification and analysis of decadal climate signals in data and models; and, studies of climate variability in terms of the dynamics of atmospheric flow regimes. Each of these project components is elaborated on below, followed by a list of publications resulting from the grant.

  14. Final Technical Report for "Collaborative Research: Regional climate-change projections through next-generation empirical and dynamical models"

    SciTech Connect (OSTI)

    Kravtsov, S.; Robertson, A. W.; Ghil, M.; Smyth, P. J.

    2011-04-08T23:59:59.000Z

    This project was a continuation of previous work under DOE CCPP funding in which we developed a twin approach of non-homogeneous hidden Markov models (NHMMs) and coupled ocean-atmosphere (O-A) intermediate-complexity models (ICMs) to identify the potentially predictable modes of climate variability, and to investigate their impacts on the regional-scale. We have developed a family of latent-variable NHMMs to simulate historical records of daily rainfall, and used them to downscale seasonal predictions. We have also developed empirical mode reduction (EMR) models for gaining insight into the underlying dynamics in observational data and general circulation model (GCM) simulations. Using coupled O-A ICMs, we have identified a new mechanism of interdecadal climate variability, involving the midlatitude oceansâ?? mesoscale eddy field and nonlinear, persistent atmospheric response to the oceanic anomalies. A related decadal mode is also identified, associated with the oceansâ?? thermohaline circulation. The goal of the continuation was to build on these ICM results and NHMM/EMR model developments and software to strengthen two key pillars of support for the development and application of climate models for climate change projections on time scales of decades to centuries, namely: (a) dynamical and theoretical understanding of decadal-to-interdecadal oscillations and their predictability; and (b) an interface from climate models to applications, in order to inform societal adaptation strategies to climate change at the regional scale, including model calibration, correction, downscaling and, most importantly, assessment and interpretation of spread and uncertainties in multi-model ensembles. Our main results from the grant consist of extensive further development of the hidden Markov models for rainfall simulation and downscaling specifically within the non-stationary climate change context together with the development of parallelized software; application of NHMMs to downscaling of rainfall projections over India; identification and analysis of decadal climate signals in data and models; and, studies of climate variability in terms of the dynamics of atmospheric flow regimes. Each of these project components is elaborated on below, followed by a list of publications resulting from the grant.

  15. Smoke inputs to climate models: optical properties and height distribution for nuclear winter studies

    SciTech Connect (OSTI)

    Penner, J.E.; Haselman, L.C. Jr.

    1985-04-01T23:59:59.000Z

    Smoke from fires produced in the aftermath of a major nuclear exchange has been predicted to cause large decreases in land surface temperatures. The extent of the decrease and even the sign of the temperature change depend on the optical characteristics of the smoke and how it is distributed with altitude. The height distribution of smoke over a fire is determined by the amount of buoyant energy produced by the fire and the amount of energy released by the latent heat of condensation of water vapor. The optical properties of the smoke depend on the size distribution of smoke particles which changes due to coagulation within the lofted plume. We present calculations demonstrating these processes and estimate their importance for the smoke source term input for climate models. For high initial smoke densities and for absorbing smoke ( m = 1.75 - 0.3i), coagulation of smoke particles within the smoke plume is predicted to first increase, then decrease, the size-integrated extinction cross section. However, at the smoke densities predicted in our model (assuming a 3% emission rate for smoke) and for our assumed initial size distribution, the attachment rates for brownian and turbulent collision processes are not fast enough to alter the smoke size distribution enough to significantly change the integrated extinction cross section. Early-time coagulation is, however, fast enough to allow further coagulation, on longer time scales, to act to decrease the extinction cross section. On these longer time scales appropriate to climate models, coagulation can decrease the extinction cross section by almost a factor of two before the smoke becomes well mixed around the globe. This process has been neglected in past climate effect evaluations, but could have a significant effect, since the extinction cross section enters as an exponential factor in calculating the light attenuation due to smoke. 10 refs., 20 figs.

  16. Research on the climatic effects of nuclear winter: Final report

    SciTech Connect (OSTI)

    Dickinson, R.E.

    1986-12-03T23:59:59.000Z

    The National Center for Atmospheric Research (NCAR) has undertaken a series of research efforts to develop and implement improvements to the Community Climate Model (CCM) needed to make the model more applicable to studies of the climatic effects of nuclear war. The development of the model improvements has reached a stage where implementation may proceed, and several of the developed routines are being incorporated into the next approved version of the CCM (CCM1). Formal documentation is being completed describing the specific model improvements that have been successfully implemented. This final report includes the series of annual proposals and progress reports that have guided the project.

  17. Modeling the Uncertain Future of a Threatened Habitat: Climate Change and Urban Growth in California Sage Scrub

    E-Print Network [OSTI]

    Riordan, Erin Coulter

    2013-01-01T23:59:59.000Z

    Under projected climate change, mediterranean-climate in theland use and climate change in mediterranean regions,TO PROJECTED CLIMATE CHANGE IN A THREATENED, MEDITERRANEAN-

  18. Forest dynamics at regional scales: predictive models constrained with inventory data

    E-Print Network [OSTI]

    Lines, Emily

    2012-06-12T23:59:59.000Z

    by scaling from key tree-level processes, but models typically have no climate dependency. In this thesis I demonstrate how large-scale national inventories combined with improvements in computational methods mean that models that incorporate the climate...

  19. Wall Design Redundancy for Improving the Moisture Performance of Building Cladding Systems in Hot-Humid Climates

    E-Print Network [OSTI]

    Graham, C. W.

    2000-01-01T23:59:59.000Z

    An investigation of approximately 4,000 buildings in the hot-humid climate locations of the United States where the potential for decay of hygroscopic building materials or corrosion of metals is moderate-to-severe found that redundant moisture...

  20. COUNTERCURRENT FLOW LIMITATION EXPERIMENTS AND MODELING FOR IMPROVED REACTOR SAFETY

    SciTech Connect (OSTI)

    Vierow, Karen

    2008-09-26T23:59:59.000Z

    This project is investigating countercurrent flow and “flooding” phenomena in light water reactor systems to improve reactor safety of current and future reactors. To better understand the occurrence of flooding in the surge line geometry of a PWR, two experimental programs were performed. In the first, a test facility with an acrylic test section provided visual data on flooding for air-water systems in large diameter tubes. This test section also allowed for development of techniques to form an annular liquid film along the inner surface of the “surge line” and other techniques which would be difficult to verify in an opaque test section. Based on experiences in the air-water testing and the improved understanding of flooding phenomena, two series of tests were conducted in a large-diameter, stainless steel test section. Air-water test results and steam-water test results were directly compared to note the effect of condensation. Results indicate that, as for smaller diameter tubes, the flooding phenomena is predominantly driven by the hydrodynamics. Tests with the test sections inclined were attempted but the annular film was easily disrupted. A theoretical model for steam venting from inclined tubes is proposed herein and validated against air-water data. Empirical correlations were proposed for air-water and steam-water data. Methods for developing analytical models of the air-water and steam-water systems are discussed, as is the applicability of the current data to the surge line conditions. This report documents the project results from July 1, 2005 through June 30, 2008.

  1. Modeling of Glass Making Processes for Improved Efficiency

    SciTech Connect (OSTI)

    Thomas P. Seward III

    2003-03-31T23:59:59.000Z

    The overall goal of this project was to develop a high-temperature melt properties database with sufficient reliability to allow mathematical modeling of glass melting and forming processes for improved product quality, improved efficiency and lessened environmental impact. It was initiated by the United States glass industry through the NSF Industry/University Center for Glass Research (CGR) at Alfred University [1]. Because of their important commercial value, six different types/families of glass were studied: container, float, fiberglass (E- and wool-types), low-expansion borosilicate, and color TV panel glasses. CGR member companies supplied production-quality glass from all six families upon which we measured, as a function of temperature in the molten state, density, surface tension, viscosity, electrical resistivity, infrared transmittance (to determine high temperature radiative conductivity), non-Newtonian flow behavior, and oxygen partial pres sure. With CGR cost sharing, we also studied gas solubility and diffusivity in each of these glasses. Because knowledge of the compositional dependencies of melt viscosity and electrical resistivity are extremely important for glass melting furnace design and operation, these properties were studied more fully. Composition variations were statistically designed for all six types/families of glass. About 140 different glasses were then melted on a laboratory scale and their viscosity and electrical resistivity measured as a function of temperature. The measurements were completed in February 2003 and are reported on here. The next steps will be (1) to statistically analyze the compositional dependencies of viscosity and electrical resistivity and develop composition-property response surfaces, (2) submit all the data to CGR member companies to evaluate the usefulness in their models, and (3) publish the results in technical journals and most likely in book form.

  2. Improvements in Hanford TRU Program Utilizing Systems Modeling and Analyses

    SciTech Connect (OSTI)

    Baynes, P.A.; Bailey, K.B.; McKenney, D.E. [Fluor Hanford, Inc., Richland, WA (United States); Uytioco, E. [Fluor Government Group, Richland, WA (United States)

    2008-07-01T23:59:59.000Z

    Hanford's Transuranic (TRU) Program is responsible for certifying contact-handled (CH) TRU waste and shipping the certified waste to the Waste Isolation Pilot Plant (WIPP). Hanford's CH TRU waste includes material that is in retrievable storage as well as above ground storage, and newly generated waste. Certifying a typical container entails retrieving and then characterizing it (Non-Destructive Examination [NDE], Non-Destructive Assay [NDA], and Head Space Gas Sampling [HSG]), validating records (data review and reconciliation), and designating the container for a payload. The certified payload is then shipped to WIPP. Systems modeling and analysis techniques were applied to Hanford's TRU Program to help streamline the certification process and increase shipping rates. The modeling and analysis yields several benefits: - Maintains visibility on system performance and predicts downstream consequences of production issues. - Predicts future system performance with higher confidence, based on tracking past performance. - Applies speculation analyses to determine the impact of proposed changes (e.g., apparent shortage of feed should not be used as basis to reassign personnel if more feed is coming in the queue). - Positively identifies the appropriate queue for all containers (e.g., discovered several containers that were not actively being worked because they were in the wrong 'physical' location - method used previously for queuing up containers). - Identifies anomalies with the various data systems used to track inventory (e.g., dimensional differences for Standard Waste Boxes). A model of the TRU Program certification process was created using custom queries of the multiple databases for managing waste containers. The model was developed using a simplified process chart based on the expected path for a typical container. The process chart was augmented with the remediation path for containers that do not meet acceptance criteria for WIPP. Containers are sorted into queues based on their current status in the process. A container can be in only one queue at any given time. Existing data systems are queried to establish the quantity of containers in each queue on any given day. This sets the amount of feed available that is then modeled to be processed according to the daily production plans. The daily production plans were created by identifying the equipment necessary and the staff that performs each process step, and determining the expected production rate for each step. Production performance is monitored on a weekly basis with Project senior staff to establish a total operating efficiency (TOE) for each step (comparing actual performance to production capacity). The unit operations were modeled to be constrained by each day's feed queue plus the performance of the preceding step. The TOE for each unit operation was applied to an integrated model to determine bottlenecks and identify areas for improvement. All of the steps were linked to predict future system performance based on available feed and integrated system-level TOE. It has been determined that at times sub-optimization of a particular unit operation is necessary to ensure the system remains balanced (e.g., having excess capacity in assay does no good if there is no feed available because the real-time radiography [RTR] is working at half capacity). Several recommendations have been provided to the Project management team resulting in improvements in the performance of TRU certification activities by Hanford's TRU Program. (authors)

  3. Global air quality and climate

    E-Print Network [OSTI]

    2012-01-01T23:59:59.000Z

    Evaluation of Chemistry- Climate Models 5, 2010. 320 S. Wu,and R. Van Dorland, in Climate Change 2007: The PhysicalInter- governmental Panel on Climate Change, ed. D. Qin, M.

  4. Assessing the Effects of Anthropogenic Aerosols on Pacific Storm Track Using a Multiscale Global Climate Model

    SciTech Connect (OSTI)

    Wang, Yuan; Wang, Minghuai; Zhang, Renyi; Ghan, Steven J.; Lin, Yun; Hu, Jiaxi; Pan, Bowen; Levy, Misti; Jiang, Jonathan; Molina, Mario J.

    2014-05-13T23:59:59.000Z

    Atmospheric aerosols impact weather and global general circulation by modifying cloud and precipitation processes, but the magnitude of cloud adjustment by aerosols remains poorly quantified and represents the largest uncertainty in estimated forcing of climate change. Here we assess the impacts of anthropogenic aerosols on the Pacific storm track using a multi-scale global aerosol-climate model (GCM). Simulations of two aerosol scenarios corresponding to the present day and pre-industrial conditions reveal long-range transport of anthropogenic aerosols across the north Pacific and large resulting changes in the aerosol optical depth, cloud droplet number concentration, and cloud and ice water paths. Shortwave and longwave cloud radiative forcing at the top of atmosphere are changed by - 2.5 and + 1.3 W m-2, respectively, by emission changes from pre-industrial to present day, and an increased cloud-top height indicates invigorated mid-latitude cyclones. The overall increased precipitation and poleward heat transport reflect intensification of the Pacific storm track by anthropogenic aerosols. Hence, this work provides for the first time a global perspective of the impacts of Asian pollution outflows from GCMs. Furthermore, our results suggest that the multi-scale modeling framework is essential in producing the aerosol invigoration effect of deep convective clouds on the global scale.

  5. Climate response to tropical cyclone-induced ocean mixing in an1 Earth system model of intermediate complexity2

    E-Print Network [OSTI]

    Climate response to tropical cyclone-induced ocean mixing in an1 Earth system model of intermediate system model of intermediate complexity. The parameterization is based on21 previously published global. Abstract19 We introduce a parameterization of ocean mixing by tropical cyclones (TCs) into20 an Earth

  6. Final Report for DOE Grant DE-FG02-07ER64470 [“Incorporation of the HYbrid Coordinate Ocean Model (HYCOM) into the Community Climate System Model (CCSM): Evaluation and Climate Applications”

    SciTech Connect (OSTI)

    Chassignet, Eric P

    2013-03-18T23:59:59.000Z

    The primary goal of the project entitled “Incorporation of the HYbrid Coordinate Ocean Model (HYCOM) into the Community Climate System Model (CCSM): Evaluation and Climate Applications” was to systematically investigate the performance of the HYbrid Coordinate Ocean Model (HYCOM) as an alternative oceanic component of the NCAR’s Community Climate System Model (CCSM). We have configured two versions of the fully coupled CCSM3/HYCOM: one with a medium resolution (T42) Community Atmospheric Model (CAM) and the other with higher resolution (T85). We have performed a comprehensive analysis of the 400-year fully coupled CCSM3/HYCOM simulations and compared the results with those from CCSM3/POP and with climatological observations, and also we have performed tuning of critical model parameters, including Smagorinsky viscosity, isopycnal diffusivity, and background vertical diffusivity. The analysis shows that most oceanic features are well represented in the CCSM3/HYCOM. The coupled CCSM3/HYCOM (T42) has been integrated for 400 years, and the results have been archived and transferred to the High Performance Computer in the Florida State Univesity. In the last year, we have made comprehensive diagnostics of the long-term simulations by the comparison with the original CCSM3/POP simulation and with the observations. To gain some understanding of the model biases, the mean climate and modes of climate variability of the two models are compared with observations. The examination includes the Northern and Southern Annular Modes (NAM and SAM), the Pacific-North-American (PNA) pattern, the Atlantic Multidecadal Oscillation (AMO), and the main Southern Ocean SST mode. We also compared the performance of ENSO simulation in the coupled models. This report summarizes the main findings from the comparison of long-term CCSM3/HYCOM and CCSM3/POP simulations.

  7. Little Ice Age glaciers in Britain: Glacier–climate modelling in the Cairngorm Mountains

    SciTech Connect (OSTI)

    Stephan Harrison; Ann V. Rowan; Neil F. Glasser; Jasper Knight; Mitchell A. Plummer; Stephanie C. Mills

    2014-02-01T23:59:59.000Z

    It is widely believed that the last glaciers in the British Isles disappeared at the end of the Younger Dryas stadial (12.9–11.7 cal. kyr BP). Here, we use a glacier–climate model driven by data from local weather stations to show for the first time that glaciers developed during the Little Ice Age (LIA) in the Cairngorm Mountains. Our model is forced from contemporary conditions by a realistic difference in mean annual air temperature of -1.5 degrees C and an increase in annual precipitation of 10%, and confirmed by sensitivity analyses. These results are supported by the presence of small boulder moraines well within Younger Dryas ice limits, and by a dating programme on a moraine in one cirque. As a result, we argue that the last glaciers in the Cairngorm Mountains (and perhaps elsewhere in upland Britain) existed in the LIA within the last few hundred years, rather than during the Younger Dryas.

  8. Sandia National Laboratories: Climate

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    to address the most challenging and demanding climate-change issues. Accelerated Climate Modeling for Energy (ACME) is designed to accel-erate the development and applica-tion of...

  9. Priorities for modeling biological processes in climates altered by nuclear war

    SciTech Connect (OSTI)

    Detling, J.K.; Kercher, J.R.; Post, W.M.; Cowles, S.W.; Harwell, M.A.

    1987-01-01T23:59:59.000Z

    This document describes research that has been accomplished or currently models the effects of reduced light and temperature on terrestrial systems. We shall divide the systems to be studied into cultivated lands and uncultivated lands. The cultivated class consists of monoculture systems in which the individual plants belong to the same age and size class. The systems in the uncultivated class consist of uneven age, multi-species assemblies of interacting plants and animals. The uncultivated class ranges from minimally managed systems, e.g., rangelands and some forests, to completely unmanaged wildlands. For the cultivated case, the variable of concern is the annual yield of the crop under consideration. The models should be able to estimate percent yield loss as a function of reductions of light and temperature. The models should be accurate for the range of environments predicted for the growing season immediately following or during which the hypothetical nuclear exchange occurs. The models should be able to estimate yield loss in any subsequent year for which climatic conditions still differ significantly from normal. For the uncultivated case, the modelling program needs to be able to predict the effects on individual plants much the same as in the cultivated case; but in addition, the modelling program will have the task of estimating the effect that these changes in individual organisms will have at higher levels of organization, i.e., on populations, communities, and regional distributions of species. 25 refs., 1 tab.

  10. On the origins of the ice ages : insolation forcing, age models, and nonlinear climate change

    E-Print Network [OSTI]

    Huybers, Peter, 1974-

    2004-01-01T23:59:59.000Z

    This thesis revolves about the relationship between orbital forcing and climate variability. To place paleo and modern climate variability in context, the spectrum of temperature variability is estimated from time-scales ...

  11. Climate change and agriculture : global and regional effects using an economic model of international trade

    E-Print Network [OSTI]

    Reilly, John M.

    1993-01-01T23:59:59.000Z

    Empirical estimates of the economic welfare implications of the impact of climate change on global agricultural production are made. Agricultural yield changes resulting from climate scenarios associated with a doubling ...

  12. Bayesian Proteoform Modeling Improves Protein Quantification of Global Proteomic Measurements

    SciTech Connect (OSTI)

    Webb-Robertson, Bobbie-Jo M.; Matzke, Melissa M.; Datta, Susmita; Payne, Samuel H.; Kang, Jiyun; Bramer, Lisa M.; Nicora, Carrie D.; Shukla, Anil K.; Metz, Thomas O.; Rodland, Karin D.; Smith, Richard D.; Tardiff, Mark F.; McDermott, Jason E.; Pounds, Joel G.; Waters, Katrina M.

    2014-12-01T23:59:59.000Z

    As the capability of mass spectrometry-based proteomics has matured, tens of thousands of peptides can be measured simultaneously, which has the benefit of offering a systems view of protein expression. However, a major challenge is that with an increase in throughput, protein quantification estimation from the native measured peptides has become a computational task. A limitation to existing computationally-driven protein quantification methods is that most ignore protein variation, such as alternate splicing of the RNA transcript and post-translational modifications or other possible proteoforms, which will affect a significant fraction of the proteome. The consequence of this assumption is that statistical inference at the protein level, and consequently downstream analyses, such as network and pathway modeling, have only limited power for biomarker discovery. Here, we describe a Bayesian model (BP-Quant) that uses statistically derived peptides signatures to identify peptides that are outside the dominant pattern, or the existence of multiple over-expressed patterns to improve relative protein abundance estimates. It is a research-driven approach that utilizes the objectives of the experiment, defined in the context of a standard statistical hypothesis, to identify a set of peptides exhibiting similar statistical behavior relating to a protein. This approach infers that changes in relative protein abundance can be used as a surrogate for changes in function, without necessarily taking into account the effect of differential post-translational modifications, processing, or splicing in altering protein function. We verify the approach using a dilution study from mouse plasma samples and demonstrate that BP-Quant achieves similar accuracy as the current state-of-the-art methods at proteoform identification with significantly better specificity. BP-Quant is available as a MatLab ® and R packages at https://github.com/PNNL-Comp-Mass-Spec/BP-Quant.

  13. Detection of CO sub 2 -induced climatic change

    SciTech Connect (OSTI)

    Wigley, T.M.L.; Jones, P.D.

    1990-07-15T23:59:59.000Z

    The aims of the US Department of Energy's CO{sub 2} Climate Research Program are to improve assessments of greenhouse-gas-induced climatic change and to define and reduce uncertainties through selected research. We propose to continue earlier work in five areas: updating, improvement and analysis of our global (land and marine) temperature data set; the development and use of multivariate techniques for the detection of greenhouse-gas-induced climatic change; the further development and use of simple transient-response climate models in order to elucidate the responses of the climate system to external and internal forcing; validation of General Circulation Models using a variety of test statistics, and the use of regression methods to produce sub-grid-scale information from GCM output. The present project addresses all of these questions. This document contains information of the progress in each area. 25 refs., 2 figs., 2 tabs.

  14. Mexican drought: an observational modeling and tree ring study of variability and climate change

    E-Print Network [OSTI]

    2009-01-01T23:59:59.000Z

    changes in Mexican agriculture over the last decade and a half are the combined result of severe climate-

  15. Evaluating sub-national building-energy efficiency policy options under uncertainty: Efficient sensitivity testing of alternative climate, technolgical, and socioeconomic futures in a regional intergrated-assessment model.

    SciTech Connect (OSTI)

    Scott, Michael J.; Daly, Don S.; Zhou, Yuyu; Rice, Jennie S.; Patel, Pralit L.; McJeon, Haewon C.; Kyle, G. Page; Kim, Son H.; Eom, Jiyong; Clarke, Leon E.

    2014-05-01T23:59:59.000Z

    Improving the energy efficiency of the building stock, commercial equipment and household appliances can have a major impact on energy use, carbon emissions, and building services. Subnational regions such as U.S. states wish to increase their energy efficiency, reduce carbon emissions or adapt to climate change. Evaluating subnational policies to reduce energy use and emissions is difficult because of the uncertainties in socioeconomic factors, technology performance and cost, and energy and climate policies. Climate change may undercut such policies. Assessing these uncertainties can be a significant modeling and computation burden. As part of this uncertainty assessment, this paper demonstrates how a decision-focused sensitivity analysis strategy using fractional factorial methods can be applied to reveal the important drivers for detailed uncertainty analysis.

  16. Modeling Potential Equilibrium States of Vegetation and Terrestrial Water Cycle of Mesoamerica under Climate Change Scenarios*

    E-Print Network [OSTI]

    Boyer, Edmond

    precipitation, the impacts of climate change on vegetation and water cycle are predicted with relatively low under Climate Change Scenarios* PABLO IMBACH,1 LUIS MOLINA,1 BRUNO LOCATELLI,# OLIVIER ROUPSARD,1,@ GIL MAHE´ ,& RONALD NEILSON,**,&& LENIN CORRALES,11 MARKO SCHOLZE,## AND PHILIPPE CIAIS @@ 1 Climate Change

  17. Light-absorbing Particles in Snow and Ice: Measurement and Modeling of Climatic and Hydrological Impact

    SciTech Connect (OSTI)

    Qian, Yun; Yasunari, Teppei J.; Doherty, Sarah J.; Flanner, M. G.; Lau, William K.; Ming, J.; Wang, Hailong; Wang, Mo; Warren, Stephen G.; Zhang, Rudong

    2015-01-01T23:59:59.000Z

    Light absorbing particles (LAP, e.g., black carbon, brown carbon, and dust) influence water and energy budgets of the atmosphere and snowpack in multiple ways. In addition to their effects associated with atmospheric heating by absorption of solar radiation and interactions with clouds, LAP in snow on land and ice can reduce the surface reflectance (a.k.a., surface darkening), which is likely to accelerate the snow aging process and further reduces snow albedo and increases the speed of snowpack melt. LAP in snow and ice (LAPSI) has been identified as one of major forcings affecting climate change, e.g. in the fourth and fifth assessment reports of IPCC. However, the uncertainty level in quantifying this effect remains very high. In this review paper, we document various technical methods of measuring LAPSI and review the progress made in measuring the LAPSI in Arctic, Tibetan Plateau and other mid-latitude regions. We also report the progress in modeling the mass concentrations, albedo reduction, radiative forcing, andclimatic and hydrological impact of LAPSI at global and regional scales. Finally we identify some research needs for reducing the uncertainties in the impact of LAPSI on global and regional climate and the hydrological cycle.

  18. Dynamics of Arctic and Sub-Arctic Climate and Atmospheric Circulation: Diagnosis of Mechanisms and Biases Using Data Assimilation

    SciTech Connect (OSTI)

    Eric T. DeWeaver

    2010-02-17T23:59:59.000Z

    The overall goal of work performed under this grant is to enhance understanding of simulations of present-day climate and greenhouse gas-induced climate change. The examination of present-day climate also includes diagnostic intercomparison of model simulations and observed mean climate and climate variability using reanalysis and satellite datasets. Enhanced understanding is desirable 1) as a prerequisite for improving simulations; 2) for assessing the credibility of model simulations and their usefulness as tools for decision support; and 3) as a means to identify robust behaviors which commonly occur over a wide range of models, and may yield insights regarding the dominant physical mechanisms which determine mean climate and produce climate change. A further objective is to investigate the use of data assimilation as a means for examining and correcting model biases. Our primary focus is on the Arctic, but the scope of the work was expanded to include the global climate system.

  19. Improved Modeling of Residential Air Conditioners and Heat Pumps for Energy Calculations

    SciTech Connect (OSTI)

    Cutler, D.; Winkler, J.; Kruis, N.; Christensen, C.; Brendemuehl, M.

    2013-01-01T23:59:59.000Z

    This report presents improved air conditioner and heat pump modeling methods in the context of whole-building simulation tools, with the goal of enabling more accurate evaluation of cost effective equipment upgrade opportunities and efficiency improvements in residential buildings.

  20. An optimal fitting approach to improve the GISS ModelE aerosol optical property parameterization using AERONET data

    E-Print Network [OSTI]

    and absorbing solar radiation and the indirect effect by interacting with water vapor to affect cloud formation and lifetime. Absorbing aerosols also have the semidirect effect by heating the atmosphere layer, reducing; Intergovernmental Panel on Climate Change, 2001]. [3] Globalscale models, which simulate the emission, transport

  1. Northeast Climate Science Center: Transposing Extreme Rainfall to Assess Climate Vulnerability

    Office of Energy Efficiency and Renewable Energy (EERE)

    Climate models predict significant increases in the magnitude and frequency of extreme rainfalls.  However, climate model projections of precipitation vary greatly across models.  For communities...

  2. The Impact of IBM Cell Technology on the Programming Paradigm in the Context of Computer Systems for Climate and Weather Models

    SciTech Connect (OSTI)

    Zhou, Shujia; Duffy, Daniel; Clune, Thomas; Suarez, Max; Williams, Samuel; Halem, Milton

    2009-01-10T23:59:59.000Z

    The call for ever-increasing model resolutions and physical processes in climate and weather models demands a continual increase in computing power. The IBM Cell processor's order-of-magnitude peak performance increase over conventional processors makes it very attractive to fulfill this requirement. However, the Cell's characteristics, 256KB local memory per SPE and the new low-level communication mechanism, make it very challenging to port an application. As a trial, we selected the solar radiation component of the NASA GEOS-5 climate model, which: (1) is representative of column physics components (half the total computational time), (2) has an extremely high computational intensity: the ratio of computational load to main memory transfers, and (3) exhibits embarrassingly parallel column computations. In this paper, we converted the baseline code (single-precision Fortran) to C and ported it to an IBM BladeCenter QS20. For performance, we manually SIMDize four independent columns and include several unrolling optimizations. Our results show that when compared with the baseline implementation running on one core of Intel's Xeon Woodcrest, Dempsey, and Itanium2, the Cell is approximately 8.8x, 11.6x, and 12.8x faster, respectively. Our preliminary analysis shows that the Cell can also accelerate the dynamics component (~;;25percent total computational time). We believe these dramatic performance improvements make the Cell processor very competitive as an accelerator.

  3. Climate change and hydropower production in the Swiss Alps:potential impacts and modelling uncertainties Hydrol. Earth Syst. Sci., 11(3), 11911205, 2007

    E-Print Network [OSTI]

    Paris-Sud XI, Université de

    climate change scenarios based on global-mean warming scenarios, the corresponding discharge model). Apart from the obvious economic interest in electricity production from water accumulated in reservoirsClimate change and hydropower production in the Swiss Alps:potential impacts and modelling

  4. Transient Climate Response in a Two-Layer Energy-Balance Model. Part I: Analytical Solution and Parameter Calibration Using CMIP5 AOGCM Experiments

    E-Print Network [OSTI]

    Ribes, Aurélien

    analyzing the global thermal properties of atmosphere­ocean coupled general circulation models (AOGCMs perturbation, some EBMs assume that the thermal energy balance of the climate system is only expressedTransient Climate Response in a Two-Layer Energy-Balance Model. Part I: Analytical Solution

  5. Improvement of an Esocid Bioenergetics Model for Juvenile Fish CASEY W. SCHOENEBECK*

    E-Print Network [OSTI]

    Improvement of an Esocid Bioenergetics Model for Juvenile Fish CASEY W. SCHOENEBECK* Department temperature are known to influence the accuracy of fish bioenergetics models. In an effort to improve the accuracy of a juvenile esocid bioenergetics model, we used a regression-based approach to develop

  6. Do Coupled Climate Models Correctly SImulate the Upward Branch of the Deept Ocean Global Conveyor?

    SciTech Connect (OSTI)

    Sarmiento, Jorge L; Downes, Stephanie; Bianchi, Daniele

    2013-01-17T23:59:59.000Z

    The large-scale meridional overturning circulation (MOC) connects the deep ocean, a major reservoir of carbon, to the other components of the climate system and must therefore be accurately represented in Earth System Models. Our project aims to address the specific question of the pathways and mechanisms controlling the upwelling branch of the MOC, a subject of significant disagreement between models and observational syntheses, and among general circulation models. Observations of these pathways are limited, particularly in regions of complex hydrography such as the Southern Ocean. As such, we rely on models to examine theories of the overturning circulation, both physically and biogeochemically. This grant focused on a particular aspect of the meridional overturning circulation (MOC) where there is currently significant disagreement between models and observationally based analyses of the MOC, and amongst general circulation models. In particular, the research focused on addressing the following questions: 1. Where does the deep water that sinks in the polar regions rise to the surface? 2. What processes are responsible for this rise? 3. Do state-of-the-art coupled GCMs capture these processes? Our research had three key components: observational synthesis, model development and model analysis. In this final report we outline the key results from these areas of research for the 2007 to 2012 grant period. The research described here was carried out primarily by graduate student, Daniele Bianchi (now a Postdoc at McGill University, Canada), and Postdoc Stephanie Downes (now a Research Fellow at The Australian national University, Australia). Additional support was provided for programmers Jennifer Simeon as well as Rick Slater.

  7. Effects of mineral aerosols on the summertime climate of southwest Asia: Incorporating subgrid variability in a dust emission scheme

    E-Print Network [OSTI]

    Marcella, Marc Pace

    [1] Improvements in modeling mineral aerosols over southwest Asia are made to the dust scheme in a regional climate model by representing subgrid variability of both wind speed and surface roughness length. The new module ...

  8. ARM - Field Campaign - Observations and Modeling of the Green...

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    proposed study will improve the understanding and representation in climate and Earth system models of clouds and aerosols as well as their interactions and coupling with the...

  9. Climate Extremes, Uncertainty and Impacts Climate Change Challenge: The Fourth Assessment Report of the Intergovernmental Panel on Climate Change

    E-Print Network [OSTI]

    Climate Extremes, Uncertainty and Impacts Climate Change Challenge: The Fourth Assessment Report of the Intergovernmental Panel on Climate Change (IPCC, AR4) has resulted in a wider acceptance of global climate change climate extremes and change impacts. Uncertainties in process studies, climate models, and associated

  10. Toward hydro-social modeling: Merging human variables and the social sciences with climate-glacier runoff models (Santa River, Peru)

    E-Print Network [OSTI]

    McKenzie, Jeffrey M.

    Toward hydro-social modeling: Merging human variables and the social sciences with climate mountain range, this paper provides a holistic hydro-social framework that identifies five major human of watershed dynamics. This hydro-social framework has wide- spread implications for hydrological modeling

  11. Climate Change and National Security

    E-Print Network [OSTI]

    Alyson, Fleming; Summer, Kelly; Summer, Martin; Lauren, Franck; Jonathan, Mark

    2015-01-01T23:59:59.000Z

    of climate change, energy security and economic stability.DoD is improving U.S. energy security and national security.www.greenpacks.org • Energy Security & Climate Change:

  12. Building America Best Practices Series: Volume 3; Builders and Buyers Handbook for Improving New Home Efficiency, Comfort, and Durability in Cold and Very Cold Climates

    SciTech Connect (OSTI)

    Not Available

    2005-08-01T23:59:59.000Z

    This best practices guide is part of a series produced by Building America. The guide book is a resource to help builders large and small build high-quality, energy-efficient homes that achieve 30% energy savings in space conditioning and water heating in the cold and very cold climates. The savings are in comparison with the 1993 Model Energy Code. The guide contains chapters for every member of the builder's team-from the manager to the site planner to the designers, site supervisors, the trades, and marketers. There is also a chapter for homeowners on how to use the book to provide help in selecting a new home or builder.

  13. Building America Best Practices Series: Volume 5; Builders and Buyers Handbook for Improving New Home Efficiency, Comfort, and Durability in the Marine Climate

    SciTech Connect (OSTI)

    Baechler, M. C.; Taylor, Z. T.; Bartlett, R.; Gilbride, T.; Hefty, M.; Steward, H.; Love, P. M.; Palmer, J. A.

    2006-10-01T23:59:59.000Z

    This best practices guide is part of a series produced by Building America. The guide book is a resource to help builders large and small build high-quality, energy-efficient homes that achieve 30% energy savings in space conditioning and water heating in the Marine climate region. The savings are in comparison with the 1993 Model Energy Code. The guide contains chapters for every member of the builder's team--from the manager to the site planner to the designers, site supervisors, the trades, and marketers. There is also a chapter for homeowners on how to use the book to provide help in selecting a new home or builder.

  14. A model for improving microbial biofuel production using a synthetic feedback loop

    E-Print Network [OSTI]

    Dunlop, Mary

    2012-01-01T23:59:59.000Z

    for improving microbial biofuel production using a synthetica model for microbial biofuel production where a syntheticcell viability and biofuel yields. Although microbes can be

  15. The Role of Stratification-Dependent Mixing for the Stability of the Atlantic Overturning in a Global Climate Model*

    E-Print Network [OSTI]

    Marzeion, Ben

    in a Global Climate Model* BEN MARZEION Nansen Environmental and Remote Sensing Center, and Bjerknes Centre oceanic heat transport. Subsequently, and in opposition to results from previous studies, the overturning, as seen, for example, in temperature reconstructions from Greenland ice cores, are often ex- plained

  16. Ocean Water Clarity and the Ocean General Circulation in a Coupled Climate Model ANAND GNANADESIKAN AND WHIT G. ANDERSON

    E-Print Network [OSTI]

    Gnanadesikan, Anand

    shortwave penetration in the high-latitude Southern Ocean causes an increase in the formation of mode waterOcean Water Clarity and the Ocean General Circulation in a Coupled Climate Model ANAND GNANADESIKAN Jersey (Manuscript received 11 October 2007, in final form 17 July 2008) ABSTRACT Ocean water clarity

  17. Modelling the impact of superimposed ice on the mass balance of an Arctic glacier under scenarios of future climate change

    E-Print Network [OSTI]

    ). A consequence of climatic warming in the high Arctic will be an increase in surface melting of glaciers and ice component of the mass accumulation of many glaciers and ice caps in thModelling the impact of superimposed ice on the mass balance of an Arctic glacier under scenarios

  18. Impacts of Climate Change on Biofuels Production

    SciTech Connect (OSTI)

    Melillo, Jerry M. [Marine Biological Laboratory, Woods Hole, MA (United States)

    2014-04-30T23:59:59.000Z

    The overall goal of this research project was to improve and use our biogeochemistry model, TEM, to simulate the effects of climate change and other environmental changes on the production of biofuel feedstocks. We used the improved version of TEM that is coupled with the economic model, EPPA, a part of MIT’s Earth System Model, to explore how alternative uses of land, including land for biofuels production, can help society meet proposed climate targets. During the course of this project, we have made refinements to TEM that include development of a more mechanistic plant module, with improved ecohydrology and consideration of plant-water relations, and a more detailed treatment of soil nitrogen dynamics, especially processes that add or remove nitrogen from ecosystems. We have documented our changes to TEM and used the model to explore the effects on production in land ecosystems, including changes in biofuels production.

  19. Modeling the effect of climate change on U.S. state-level buildings energy demands in an integrated assessment framework

    SciTech Connect (OSTI)

    Zhou, Yuyu; Clarke, Leon E.; Eom, Jiyong; Kyle, G. Page; Patel, Pralit L.; Kim, Son H.; Dirks, James A.; Jensen, Erik A.; Liu, Ying; Rice, Jennie S.; Schmidt, Laurel C.; Seiple, Timothy E.

    2014-01-01T23:59:59.000Z

    As long-term socioeconomic transformation and energy service expansion show large spatial heterogeneity, advanced understanding of climate impact on building energy use at the sub-national level will offer useful insights into climate policy and regional energy system planning. In this study, we presented a detailed building energy model with a U.S. state-level representation, nested in the GCAM integrated assessment framework. We projected state-level building energy demand and its spatial pattern over the century, considering the impact of climate change based on the estimates of heating and cooling degree days derived from downscaled USGS CASCaDE temperature data. The result indicates that climate change has a large impact on heating and cooling building energy and fuel use at the state level, exhibiting large spatial heterogeneity across states (ranges from -10% to +10%). The sensitivity analysis reveals that the building energy demand is subject to multiple key factors, such as the magnitude of climate change, the choice of climate models, and the growth of population and GDP, and that their relative contributions vary greatly across the space. The scale impact in building energy use modeling highlights the importance of constructing a building energy model with the spatially-explicit representation of socioeconomics, energy system development, and climate change. These findings will help the climate-based policy decision and energy system, especially utility planning related to building sector at the U.S. state and regional level facing the potential climate change.

  20. Improving Face Recognition Performance Using a Hierarchical Bayesian Model

    E-Print Network [OSTI]

    Shikaripur Nadig, Ashwini

    2010-04-27T23:59:59.000Z

    which can result in an improved recognition performance over already existing baseline approaches. We use Kernelized Fisher Discriminant Analysis (KFLD) as our baseline as it is superior to PCA in a way that it produces well separated classes even under...

  1. Improving behavioral realism in hybrid energy-economy models using discrete choice

    E-Print Network [OSTI]

    Improving behavioral realism in hybrid energy-economy models using discrete choice studies Abstract Hybrid energy-economy models combine top-down and bottom-up approaches to explore behaviorally models to inform key behavioral parameters in CIMS, a hybrid model. The discrete choice models

  2. Comparison of simplified models of urban climate for improved prediction of building energy use in cities

    E-Print Network [OSTI]

    Street, Michael A. (Michael Anthony)

    2013-01-01T23:59:59.000Z

    Thermal simulation of buildings is a requisite tool in the design of low-energy buildings, yet, definition of weather boundary conditions during simulation of urban buildings suffers from a lack of data that accounts for ...

  3. Using A-Train Arctic cloud observations to constrain and improve climate models

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative1 First Use of Energy for All Purposes (Fuel and Nonfuel), 2002; Level:Energy: Grid Integration Redefining What'sis Taking Over OurThe Iron SpinPrinceton PlasmaAfternoon4.CCSM4large.jpgbriefingUses of radiation

  4. Use of ARM Data to address the Climate Change Further Development and Applications of A Multi-scale Modeling Framework

    SciTech Connect (OSTI)

    David A. Randall; Marat Khairoutdinov

    2007-12-14T23:59:59.000Z

    The Colorado State University (CSU) Multi-scale Modeling Framework (MMF) is a new type of general circulation model (GCM) that replaces the conventional parameterizations of convection, clouds and boundary layer with a cloud-resolving model (CRM) embedded into each grid column. The MMF that we have been working with is a “super-parameterized” version of the Community Atmosphere Model (CAM). As reported in the publications listed below, we have done extensive work with the model. We have explored the MMF’s performance in several studies, including an AMIP run and a CAPT test, and we have applied the MMF to an analysis of climate sensitivity.

  5. An improved structural mechanics model for the FRAPCON nuclear fuel performance code

    E-Print Network [OSTI]

    Mieloszyk, Alexander James

    2012-01-01T23:59:59.000Z

    In order to provide improved predictions of Pellet Cladding Mechanical Interaction (PCMI) for the FRAPCON nuclear fuel performance code, a new model, the FRAPCON Radial-Axial Soft Pellet (FRASP) model, was developed. This ...

  6. Scaling analyses of forcings and outputs of a simplified Last1 Millennium climate model2

    E-Print Network [OSTI]

    Lovejoy, Shaun

    with the Detrended Fluctuation Analysis method as 34 well as the effect of certain data pretreatments. 35 This suggests that at centennial and longer scales, new slow climate

  7. Modeling the Ranges of Stresses for Different Climates/Applications (Presentation)

    SciTech Connect (OSTI)

    Kempe, M.; Kurtz, S.; Wohlgemuth, J.; Miller, D.; Reese, M.; Dameron, A.

    2011-07-01T23:59:59.000Z

    This presentation outlines the environmental, site-specific attributes that must be considered when evaluating the durability of photovoltaic (PV) modules in different climates/applications.

  8. Submitted to BAMS v5, 13/10/2011 Documenting the climate modelling process: how climate scientists now share their

    E-Print Network [OSTI]

    Guilyardi, Eric

    (DKRZ, Germany), Sylvia Murphy (NOAA, US), Karl Taylor (PCMDI, US) and the METAFOR team In earth system system models"). The complexity of these simulators, measured in terms of the number of the processes we modelling, the performance of common simulation experiments by multiple research groups has emerged

  9. Improvements to simulation of Madden Julian Oscillation due to deep1 convection parameterization modifications in the Community Climate2

    E-Print Network [OSTI]

    Jochum, Markus

    coherent structures, which are43 important features of observed MJOs. The conclusions are supported by two, and small-scale convection (e.g., Blade and Hartmann 1993; Hu and Randall 1995;53 Kemball-Cook and Weare. 1999). A key factor in improving MJO simulation is the convective58 parameterization. Many tests have

  10. Improvements to Hydrogen Delivery Scenario Analysis Model (HDSAM) and

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page on Google Bookmark EERE: Alternative Fuels DataDepartment of Energy Your Density Isn't YourTransport(Fact Sheet),EnergyImprovement of the Lost Foam Casting Process Improvement

  11. Vapor intrusion modeling : limitations, improvements, and value of information analyses

    E-Print Network [OSTI]

    Friscia, Jessica M. (Jessica Marie)

    2014-01-01T23:59:59.000Z

    Vapor intrusion is the migration of volatile organic compounds (VOCs) from a subsurface source into the indoor air of an overlying building. Vapor intrusion models, including the Johnson and Ettinger (J&E) model, can be ...

  12. Improving the Modeling of Hydrogen Solubility in Heavy Oil Cuts Using an Augmented

    E-Print Network [OSTI]

    Paris-Sud XI, Université de

    Improving the Modeling of Hydrogen Solubility in Heavy Oil Cuts Using an Augmented Grayson Streed -- Improving the Modeling of Hydrogen Solubility in Heavy Oil Cuts Using an Augmented Grayson Streed (AGS for calculating hydrogen solubility in petroleum fluids. However, its accuracy becomes very bad when very heavy

  13. An improved model of the lightning electromagnetic field interaction with the D-region ionosphere

    E-Print Network [OSTI]

    14 March 2012. [1] We present an improved time-domain model of the lightning electromagnetic pulse. Introduction [2] Lightning discharges produce both an electromagnetic pulse (EMP), due to the rapid lightningAn improved model of the lightning electromagnetic field interaction with the D-region ionosphere R

  14. CFD modeling of entrained-flow coal gasifiers with improved physical and chemical sub-models

    SciTech Connect (OSTI)

    Ma, J.; Zitney, S.

    2012-01-01T23:59:59.000Z

    Optimization of an advanced coal-fired integrated gasification combined cycle system requires an accurate numerical prediction of gasifier performance. While the turbulent multiphase reacting flow inside entrained-flow gasifiers has been modeled through computational fluid dynamic (CFD), the accuracy of sub-models requires further improvement. Built upon a previously developed CFD model for entrained-flow gasification, the advanced physical and chemical sub-models presented here include a moisture vaporization model with consideration of high mass transfer rate, a coal devolatilization model with more species to represent coal volatiles and heating rate effect on volatile yield, and careful selection of global gas phase reaction kinetics. The enhanced CFD model is applied to simulate two typical oxygen-blown entrained-flow configurations including a single-stage down-fired gasifier and a two-stage up-fired gasifier. The CFD results are reasonable in terms of predicted carbon conversion, syngas exit temperature, and syngas exit composition. The predicted profiles of velocity, temperature, and species mole fractions inside the entrained-flow gasifier models show trends similar to those observed in a diffusion-type flame. The predicted distributions of mole fractions of major species inside both gasifiers can be explained by the heterogeneous combustion and gasification reactions and the homogeneous gas phase reactions. It was also found that the syngas compositions at the CFD model exits are not in chemical equilibrium, indicating the kinetics for both heterogeneous and gas phase homogeneous reactions are important. Overall, the results achieved here indicate that the gasifier models reported in this paper are reliable and accurate enough to be incorporated into process/CFD co-simulations of IGCC power plants for systemwide design and optimization.

  15. Global well-posedness of strong solutions to a tropical climate model

    E-Print Network [OSTI]

    Li, Jinkai

    2015-01-01T23:59:59.000Z

    In this paper, we consider the Cauchy problem to the TROPIC CLIMATE MODEL derived by Frierson-Majda-Pauluis in [Comm. Math. Sci, Vol. 2 (2004)] which is a coupled system of the barotropic and the first baroclinic modes of the velocity and the typical midtropospheric temperature. The system considered in this paper has viscosities in the momentum equations, but no diffusivity in the temperature equation. We establish here the global well-posedness of strong solutions to this model. In proving the global existence of strong solutions, to overcome the difficulty caused by the absence of the diffusivity in the temperature equation, we introduce a new velocity $w$ (called the pseudo baroclinic velocity), which has more regularities than the original baroclinic mode of the velocity. An auxiliary function $\\phi$, which looks like the effective viscous flux for the compressible Navier-Stokes equations, is also introduced to obtain the $L^\\infty$ bound of the temperature. Regarding the uniqueness, we use the idea of p...

  16. The role of solar absorption in climate and climate change

    E-Print Network [OSTI]

    1 The role of solar absorption in climate and climate change William Collins UC Berkeley Research Boulder, Colorado, USA #12;2 Prior Research on Absorption and Climate Field Experiments: · Central · Climate with enhanced cloud absorption Synthesis of models and aerosol observations: · Development

  17. Impact of subgrid-scale radiative heating variability on the stratocumulus-to-trade cumulus transition in climate models

    SciTech Connect (OSTI)

    Xiao, Heng; Gustafson, William I.; Wang, Hailong

    2014-04-29T23:59:59.000Z

    Subgrid-scale interactions between turbulence and radiation are potentially important for accurately reproducing marine low clouds in climate models. To better understand the impact of these interactions, the Weather Research and Forecasting (WRF) model is configured for large eddy simulation (LES) to study the stratocumulus-to-trade cumulus (Sc-to-Cu) transition. Using the GEWEX Atmospheric System Studies (GASS) composite Lagrangian transition case and the Atlantic Trade Wind Experiment (ATEX) case, it is shown that the lack of subgrid-scale turbulence-radiation interaction, as is the case in current generation climate models, accelerates the Sc-to-Cu transition. Our analysis suggests that in cloud-topped boundary layers subgrid-scale turbulence-radiation interactions contribute to stronger production of temperature variance, which in turn leads to stronger buoyancy production of turbulent kinetic energy and helps to maintain the Sc cover.

  18. Collaboration between observationalists, theoreti-cians, and process and climate modelers leads to new

    E-Print Network [OSTI]

    Ozgökmen, Tamay M.

    Ökmen, hartmut PeterS, Jim Price, uLrike riemenSchneiDer, WanLi Wu, Xiaobiao Xu, anD Jiayan yang Fig. 1. Location used for climate predictions and projections of future climate change (Solomon et al. 2007ETEOROLOGICaL SOCIETy | #12;from the subtropical Mediterranean (Price et al. 1993) and Red Seas (Peters et al. 2005

  19. Modeling economic impacts of climate change on U.S. forests

    E-Print Network [OSTI]

    Sousa, Claudio Ney Martins De

    1994-01-01T23:59:59.000Z

    Climate change is expected to modify forest growth. As a result, the forestry sector of the United States could be affected. The primary objective of this study was to examine the economic impacts of climate change on the U.S. forestry sector...

  20. 3D modelling of the early Martian Climate under a denser CO2 atmosphere: Temperatures and CO2 ice clouds

    E-Print Network [OSTI]

    Forget, Francois; Millour, Ehouarn; Madeleine, Jean-Baptiste; Kerber, Laura; Leconte, Jeremy; Marcq, Emmanuel; Haberle, Robert M

    2012-01-01T23:59:59.000Z

    On the basis of geological evidence, it is often stated that the early martian climate was warm enough for liquid water to flow on the surface thanks to the greenhouse effect of a thick atmosphere. We present 3D global climate simulations of the early martian climate performed assuming a faint young sun and a CO2 atmosphere with pressure between 0.1 and 7 bars. The model includes a detailed radiative transfer model using revised CO2 gas collision induced absorption properties, and a parameterisation of the CO2 ice cloud microphysical and radiative properties. A wide range of possible climates is explored by using various values of obliquities, orbital parameters, cloud microphysic parameters, atmospheric dust loading, and surface properties. Unlike on present day Mars, for pressures higher than a fraction of a bar, surface temperatures vary with altitude because of the adiabatic cooling and warming of the atmosphere when it moves vertically. In most simulations, CO2 ice clouds cover a major part of the planet...

  1. Evaluation of Mixed-Phase Cloud Microphysics Parameterizations with the NCAR Single Column Climate Model (SCAM) and ARM Observations

    SciTech Connect (OSTI)

    Liu, X; Ghan, SJ; Xie, S

    2007-04-01T23:59:59.000Z

    Mixed-phase stratus clouds are ubiquitous in the Arctic and play an important role in climate in this region. However, climate models have generally proven unsuccessful at simulating the partitioning of condensed water into liquid droplets and ice crystals in these Arctic clouds, which affect modeled cloud phase, cloud lifetime and radiative properties. An ice nucleation parameterization and a vapor deposition scheme were developed that together provide a physically-consistent treatment of mixed-phase clouds in global climate models. These schemes have been implemented in the National Center for Atmospheric Research (NCAR) Community Atmospheric Model Version 3 (CAM3). This report documents the performance of these schemes against ARM Mixed-phase Arctic Cloud Experiment (M-PACE) observations using the CAM single column model version (SCAM). SCAM with our new schemes has a more realistic simulation of the cloud phase structure and the partitioning of condensed water into liquid droplets against observations during the M-PACE than the standard CAM simulations.

  2. USDA Forest Service Proceedings RMRS-P-18. 2001. 325 Modeling Aspen Responses to Climatic Warming and Insect Defoliation in Western Canada Hogg

    E-Print Network [OSTI]

    USDA Forest Service Proceedings RMRS-P-18. 2001. 325 Modeling Aspen Responses to Climatic Warming Aspen Responses to Climatic Warming and Insect Defoliation in Western Canada E. H. (Ted) Hogg1 Abstract change on boreal aspen forests may not become evident until after major insect outbreaks have occurred

  3. Improving Air-Conditioner and Heat Pump Modeling (Presentation)

    SciTech Connect (OSTI)

    Winkler, J.

    2012-03-01T23:59:59.000Z

    A new approach to modeling residential air conditioners and heat pumps allows users to model systems by specifying only the more readily-available SEER/EER/HSPF-type metrics. Manufacturer data was used to generate full sets of model inputs for over 450 heat pumps and air conditioners. A sensitivity analysis identified which inputs can be safely defaulted 'behind-the-scenes' without negatively impacting the reliability of energy simulations.

  4. Optical properties are an important way to understand how climate change is altering the oceans we rely on. Dr David Antoine leads the BIOCAREX project in improving analysis of optical

    E-Print Network [OSTI]

    Antoine, David

    Optical properties are an important way to understand how climate change is altering the oceans we rely on. Dr David Antoine leads the BIOCAREX project in improving analysis of optical properties. Here, he discusses bio-optics and their application in the Mediterranean Sea As an introduction could you

  5. U.S. Senate Committee on Commerce, Science and Transportation Hearing on "A Time for Change: Improving the Federal Climate Change

    E-Print Network [OSTI]

    of the SAPs address the sensitivity and adaptability of ecosystems and human systems to climate change, the Climate Change Science Program has undertaken to produce 21 Synthesis and Assessment Products (SAPs of forces bringing about changes, and reducing uncertainty in projections of how climate may change. Seven

  6. A New Double-Moment Microphysics Parameterization for Application in Cloud and Climate Models. Part II: Single-Column Modeling of Arctic Clouds

    E-Print Network [OSTI]

    Shupe, Matthew

    of the arctic bound- ary layer, the presence of leads (cracks) in the sea ice surface, the persistence of mixed-phaseA New Double-Moment Microphysics Parameterization for Application in Cloud and Climate Models. Part- dicted cloud boundaries and total cloud fraction compare reasonably well with observations. Cloud phase

  7. Improved di-neutron cluster model for 6He scattering

    E-Print Network [OSTI]

    A. M. Moro; K. Rusek; J. M. Arias; J. Gomez-Camacho; M. Rodriguez-Gallardo

    2007-03-01T23:59:59.000Z

    The structure of the three-body Borromean nucleus 6He is approximated by a two-body di-neutron cluster model. The binding energy of the 2n-\\alpha system is determined to obtain a correct description of the 2n-\\alpha coordinate, as given by a realistic three-body model calculation. The model is applied to describe the break-up effects in elastic scattering of 6He on several targets, for which experimental data exist. We show that an adequate description of the di-neutron-core degree of freedom permits a fairly accurate description of the elastic scattering of 6He on different targets.

  8. Cirrus clouds in a global climate model with a statistical cirrus cloud scheme

    SciTech Connect (OSTI)

    Wang, Minghuai; Penner, Joyce E.

    2010-06-21T23:59:59.000Z

    A statistical cirrus cloud scheme that accounts for mesoscale temperature perturbations is implemented in a coupled aerosol and atmospheric circulation model to better represent both subgrid-scale supersaturation and cloud formation. This new scheme treats the effects of aerosol on cloud formation and ice freezing in an improved manner, and both homogeneous freezing and heterogeneous freezing are included. The scheme is able to better simulate the observed probability distribution of relative humidity compared to the scheme that was implemented in an older version of the model. Heterogeneous ice nuclei (IN) are shown to decrease the frequency of occurrence of supersaturation, and improve the comparison with observations at 192 hPa. Homogeneous freezing alone can not reproduce observed ice crystal number concentrations at low temperatures (<205 K), but the addition of heterogeneous IN improves the comparison somewhat. Increases in heterogeneous IN affect both high level cirrus clouds and low level liquid clouds. Increases in cirrus clouds lead to a more cloudy and moist lower troposphere with less precipitation, effects which we associate with the decreased convective activity. The change in the net cloud forcing is not very sensitive to the change in ice crystal concentrations, but the change in the net radiative flux at the top of the atmosphere is still large because of changes in water vapor. Changes in the magnitude of the assumed mesoscale temperature perturbations by 25% alter the ice crystal number concentrations and the net radiative fluxes by an amount that is comparable to that from a factor of 10 change in the heterogeneous IN number concentrations. Further improvements on the representation of mesoscale temperature perturbations, heterogeneous IN and the competition between homogeneous freezing and heterogeneous freezing are needed.

  9. Advanced Measurement and Modeling Techniques for Improved SOFC Cathodes

    SciTech Connect (OSTI)

    Stuart Adler; L. Dunyushkina; S. Huff; Y. Lu; J. Wilson

    2006-12-31T23:59:59.000Z

    The goal of this project was to develop an improved understanding of factors governing performance and degradation of mixed-conducting SOFC cathodes. Two new diagnostic tools were developed to help achieve this goal: (1) microelectrode half-cells for improved isolation of cathode impedance on thin electrolytes, and (2) nonlinear electrochemical impedance spectroscopy (NLEIS), a variant of traditional impedance that allows workers to probe nonlinear rates as a function of frequency. After reporting on the development and efficacy of these tools, this document reports on the use of these and other tools to better understand performance and degradation of cathodes based on the mixed conductor La{sub 1-x}Sr{sub x}CoO{sub 3-{delta}} (LSC) on gadolinia or samaria-doped ceria (GDC or SDC). We describe the use of NLEIS to measure O{sub 2} exchange on thin-film LSC electrodes, and show that O{sub 2} exchange is most likely governed by dissociative adsorption. We also describe parametric studies of porous LSC electrodes using impedance and NLEIS. Our results suggest that O{sub 2} exchange and ion transport co-limit performance under most relevant conditions, but it is O{sub 2} exchange that is most sensitive to processing, and subject to the greatest degradation and sample-to-sample variation. We recommend further work that focuses on electrodes of well-defined or characterized geometry, and probes the details of surface structure, composition, and impurities. Parallel work on primarily electronic conductors (LSM) would also be of benefit to developers, and to improved understanding of surface vs. bulk diffusion.

  10. Improvements of Nuclear Data and Its Uncertainties by Theoretical Modeling

    Office of Scientific and Technical Information (OSTI)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative1 First Use of Energy for All Purposes (Fuel and Nonfuel), 2002; Level: National5Sales for4,645 3,625 1,006 492 742EnergyOn AprilAElectronicCurves | SciTech Connect Journal Article: Improved Dark Energy|

  11. Improvements to the SHDOM Radiative Transfer Modeling Package

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative1 First Use of Energy for All Purposes (Fuel and Nonfuel), 2002; Level: National5Sales for4,645U.S. DOEThe Bonneville PowerCherries 82981-1cnHigh School footballHydrogenITLaboratory in InductivelyImprovements to

  12. Improved Geothermometry Through Multivariate Reaction Path Modeling and

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page on Google Bookmark EERE: Alternative Fuels DataDepartment of Energy Your Density Isn't YourTransport(Fact Sheet),Energy PetroleumEnergyImplementingImprove MotorEvaluation of

  13. Increasing NOAA's computational capacity to improve global forecast modeling

    E-Print Network [OSTI]

    Hamill, Tom

    Systems Division Stephen J. Lord Director, NWS NCEP Environmental Modeling Center 19 July 2010 (303) 4973060 tom.hamill@noaa.gov #12; 2 Executive Summary The accuracy of many

  14. Climate VISION: Events

    Office of Scientific and Technical Information (OSTI)

    Efficiency and CO2 Intensity Improvement (PDF 24 KB) October 24-26, 2005 12th Annual EPA Natural Gas STAR Workshop September 28-30, 2005 Climate RESOLVE GHG Management Workshop...

  15. Dissemination of Climate Model Output to the Public and Commercial Sector

    SciTech Connect (OSTI)

    Robert Stockwell, PhD

    2010-09-23T23:59:59.000Z

    Climate is defined by the Glossary of Meteorology as the mean of atmospheric variables over a period of time ranging from as short as a few months to multiple years and longer. Although the term climate is often used to refer to long-term weather statistics, the broader definition of climate is the time evolution of a system consisting of the atmosphere, hydrosphere, lithosphere, and biosphere. Physical, chemical, and biological processes are involved in interactions among the components of the climate system. Vegetation, soil moisture, and glaciers are part of the climate system in addition to the usually considered temperature and precipitation (Pielke, 2008). Climate change refers to any systematic change in the long-term statistics of climate elements (such as temperature, pressure, or winds) sustained over several decades or longer. Climate change can be initiated by external forces, such as cyclical variations in the Earth's solar orbit that are thought to have caused glacial and interglacial periods within the last 2 million years (Milankovitch, 1941). However, a linear response to astronomical forcing does not explain many other observed glacial and interglacial cycles (Petit et al., 1999). It is now understood that climate is influenced by the interaction of solar radiation with atmospheric greenhouse gasses (e.g., carbon dioxide, chlorofluorocarbons, methane, nitrous oxide, etc.), aerosols (airborne particles), and Earth's surface. A significant aspect of climate are the interannual cycles, such as the El Nino La Nina cycle which profoundly affects the weather in North America but is outside the scope of weather forecasts. Some of the most significant advances in understanding climate change have evolved from the recognition of the influence of ocean circulations upon the atmosphere (IPCC, 2007). Human activity can affect the climate system through increasing concentrations of atmospheric greenhouse gases, air pollution, increasing concentrations of aerosol, and land alteration. A particular concern is that atmospheric levels of CO{sub 2} may be rising faster than at any time in Earth's history, except possibly following rare events like impacts from large extraterrestrial objects (AMS, 2007). Atmospheric CO{sub 2} concentrations have increased since the mid-1700s through fossil fuel burning and changes in land use, with more than 80% of this increase occurring since 1900. The increased levels of CO{sub 2} will remain in the atmosphere for hundreds to thousands of years. The complexity of the climate system makes it difficult to predict specific aspects of human-induced climate change, such as exactly how and where changes will occur, and their magnitude. The Intergovernmental Panel for Climate Change (IPCC) was established by World Meteorological Organization (WMO) and the United Nations in 1988. The IPCC was tasked with assessing the scientific, technical and socioeconomic information needed to understand the risk of human-induced climate change, its observed and projected impacts, and options for adaptation and mitigation. The IPCC concluded in its Fourth Assessment Report (AR4) that warming of the climate system is unequivocal, and that most of the observed increase in globally averaged temperatures since the mid-20th century is very likely due to the observed increased in anthropogenic greenhouse gas concentrations (IPCC, 2007).

  16. Carbon-nitrogen interactions regulate climate-carbon cycle feedbacks: results from an atmosphere-ocean general circulation model

    E-Print Network [OSTI]

    Thornton, P. E.; Doney, S. C.; Lindsay, Keith; Moore, J. K.; Mahowald, N. M.; Randerson, J. T.; Fung, I.; Lamarque, J. F.; Feddema, Johannes J.

    2009-01-01T23:59:59.000Z

    Biogeosciences, 6, 2099–2120, 2009 www.biogeosciences.net/6/2099/2009/ © Author(s) 2009. This work is distributed under the Creative Commons Attribution 3.0 License. Biogeosciences Carbon-nitrogen interactions regulate climate-carbon cycle feedbacks.... Inclusion of fundamental ecological interactions between carbon and nitrogen cycles in the land component of an atmosphere-ocean general circulation model (AOGCM) leads to decreased carbon uptake associated with CO2 fertil- ization, and increased carbon...

  17. Coastal communities and climate change : a dynamic model of risk perception, storms, and adaptation

    E-Print Network [OSTI]

    Franck, Travis Read

    2009-01-01T23:59:59.000Z

    Climate change impacts, including sea-level rise and changes in tropical storm frequency and intensity, will pose signicant challenges to city planners and coastal zone managers trying to make wise investment and protection ...

  18. Modeling of hydrologic conditions and solute movement in processed oil shale waste embankments under simulated climatic conditions

    SciTech Connect (OSTI)

    Reeves, T.L.; Turner, J.P.; Hasfurther, V.R.; Skinner, Q.D.

    1992-06-01T23:59:59.000Z

    The scope of this program is to study interacting hydrologic, geotechnical, and chemical factors affecting the behavior and disposal of combusted processed oil shale. The research combines bench-scale testing with large scale research sufficient to describe commercial scale embankment behavior. The large scale approach was accomplished by establishing five lysimeters, each 7.3 {times} 3.0 {times} 3.0 m deep, filled with processed oil shale that has been retorted and combusted by the Lurgi-Ruhrgas (Lurgi) process. Approximately 400 tons of Lurgi processed oil shale waste was provided by RBOSC to carry out this study. Research objectives were designed to evaluate hydrologic, geotechnical, and chemical properties and conditions which would affect the design and performance of large-scale embankments. The objectives of this research are: assess the unsaturated movement and redistribution of water and the development of potential saturated zones and drainage in disposed processed oil shale under natural and simulated climatic conditions; assess the unsaturated movement of solubles and major chemical constituents in disposed processed oil shale under natural and simulated climatic conditions; assess the physical and constitutive properties of the processed oil shale and determine potential changes in these properties caused by disposal and weathering by natural and simulated climatic conditions; assess the use of previously developed computer model(s) to describe the infiltration, unsaturated movement, redistribution, and drainage of water in disposed processed oil shale; evaluate the stability of field scale processed oil shale solid waste embankments using computer models.

  19. Modeling of hydrologic conditions and solute movement in processed oil shale waste embankments under simulated climatic conditions

    SciTech Connect (OSTI)

    Reeves, T.L.; Turner, J.P.; Hasfurther, V.R.; Skinner, Q.D.

    1992-06-01T23:59:59.000Z

    The scope of this program is to study interacting hydrologic, geotechnical, and chemical factors affecting the behavior and disposal of combusted processed oil shale. The research combines bench-scale testing with large scale research sufficient to describe commercial scale embankment behavior. The large scale approach was accomplished by establishing five lysimeters, each 7.3 [times] 3.0 [times] 3.0 m deep, filled with processed oil shale that has been retorted and combusted by the Lurgi-Ruhrgas (Lurgi) process. Approximately 400 tons of Lurgi processed oil shale waste was provided by RBOSC to carry out this study. Research objectives were designed to evaluate hydrologic, geotechnical, and chemical properties and conditions which would affect the design and performance of large-scale embankments. The objectives of this research are: assess the unsaturated movement and redistribution of water and the development of potential saturated zones and drainage in disposed processed oil shale under natural and simulated climatic conditions; assess the unsaturated movement of solubles and major chemical constituents in disposed processed oil shale under natural and simulated climatic conditions; assess the physical and constitutive properties of the processed oil shale and determine potential changes in these properties caused by disposal and weathering by natural and simulated climatic conditions; assess the use of previously developed computer model(s) to describe the infiltration, unsaturated movement, redistribution, and drainage of water in disposed processed oil shale; evaluate the stability of field scale processed oil shale solid waste embankments using computer models.

  20. Sandia National Laboratories: Global Climate & Energy

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Rates of Second Key Atmospheric Component On May 1, 2013, in Analysis, Capabilities, Climate, CRF, Energy, Facilities, Global Climate & Energy, Modeling & Analysis, News, News &...

  1. Detection of greenhouse-gas-induced climatic change. Progress report, 1 December 1991--30 June 1992

    SciTech Connect (OSTI)

    Wigley, T.M.L.; Jones, P.D.

    1992-07-15T23:59:59.000Z

    The aims of the US Department of Energy`s Carbon Dioxide Research Program are to improve assessments of greenhouse-gas-induced climatic change and to define and reduce uncertainties through selected research. This project will address: The regional and seasonal details of the expected climatic changes; how rapidly will these changes occur; how and when will the climatic effects of CO{sub 2} and other greenhouse gases be first detected; and the relationships between greenhouse-gas-induced climatic change and changes caused by other external and internal factors. The present project addresses all of these questions. Many of the diverse facets of greenhouse-gas-related climate research can be grouped under three interlinked subject areas: modeling, first detection and supporting data. This project will include the analysis of climate forcing factors, the development and refinement of transient response climate models, and the use of instrumental data in validating General Circulation Models (GCMs).

  2. Tropical and Subtropical Cloud Transitions in Weather and Climate Prediction Models: The GCSS/WGNE Pacific Cross-Section Intercomparison (GPCI)

    E-Print Network [OSTI]

    Randall, David A.

    , Paris, France e Canadian Centre for Climate Modelling and Analysis, Victoria, British Columbia, Canada f, Melbourne, Victoria, Australia i Monash University, Melbourne, Victoria, Australia j Department of Earth for the season June­July­August

  3. Final Technical Report for Collaborative Research: Regional climate-change projections through next-generation empirical and dynamical models, DE-FG02-07ER64429

    SciTech Connect (OSTI)

    Smyth, Padhraic [University of California, Irvine

    2013-07-22T23:59:59.000Z

    This is the final report for a DOE-funded research project describing the outcome of research on non-homogeneous hidden Markov models (NHMMs) and coupled ocean-atmosphere (O-A) intermediate-complexity models (ICMs) to identify the potentially predictable modes of climate variability, and to investigate their impacts on the regional-scale. The main results consist of extensive development of the hidden Markov models for rainfall simulation and downscaling specifically within the non-stationary climate change context together with the development of parallelized software; application of NHMMs to downscaling of rainfall projections over India; identification and analysis of decadal climate signals in data and models; and, studies of climate variability in terms of the dynamics of atmospheric flow regimes.

  4. An integrated assessment modeling framework for uncertainty studies in global and regional climate change: the MIT IGSM-CAM (version 1.0)

    E-Print Network [OSTI]

    Monier, Erwan

    This paper describes a computationally efficient framework for uncertainty studies in global and regional climate change. In this framework, the Massachusetts Institute of Technology (MIT) Integrated Global System Model ...

  5. USING NETWORKS OF JOURNEYS TO IMPROVE A PETROL MARKET MODEL

    E-Print Network [OSTI]

    Clark, Joanna

    at the micro level are not tied to global level variables like oil prices); the parameters are often difficult interaction models. 1 INTRODUCTION The petrol price market is a highly competitive market. Despite pressures vehicle per year. Consumers are becoming ever more aware of petrol prices; internet sites in the UK

  6. Model checking For Improved Adaptive Behaviour Alice Miller

    E-Print Network [OSTI]

    Miller, Alice

    illustrate the power of this ap- proach by showing how a previous assumption about the system, gained though of the real system, for example, a non opti- mal sensor setup. In this paper, we describe a formal model, adaptive be- haviour, PROMELA. Abstract Closed loop systems are traditionally analysed using sim- ulation

  7. Can a more realistic model error structure improve the parameter estimation in modelling the dynamics of sh populations?

    E-Print Network [OSTI]

    Chen, Yong

    or applying an estimation method that is robust to the error structure assumption in modelling the dynamicsCan a more realistic model error structure improve the parameter estimation in modelling the dynamics of ®sh populations? Y. Chena,* , J.E. Paloheimob a Fisheries Conservation Chair Program, Fisheries

  8. Wake models are used to improve predictions of Annual Energy Production (AEP) of wind farms.

    E-Print Network [OSTI]

    Daraio, Chiara

    ·Wake models are used to improve predictions of Annual Energy Production (AEP) of wind farms. ·Wake measurements in the ETHZ facility compare well with measurements at the Horns Rev offshore wind farm models take account of the effects of wakes on downstream wind turbines. ·Wake models used in the wind

  9. Improved Economic Operation of MSWC Plants with a New Model Based PID Control Strategy

    E-Print Network [OSTI]

    Van den Hof, Paul

    Improved Economic Operation of MSWC Plants with a New Model Based PID Control Strategy M. Leskens the performance of the MSWC plant combustion control system, which typically is of the PID-type. In this paper models. More specific, from a closer analysis of the dynamics of these models a new PID-type of MSWC

  10. Improving Efficiency of Data Assimilation Procedure for a Biomechanical Heart Model by

    E-Print Network [OSTI]

    Paris-Sud XI, Université de

    Improving Efficiency of Data Assimilation Procedure for a Biomechanical Heart Model by Representing to perform parameter estimation in a biomechanical model of the heart using synthetic observations [1, 3, 7, 8, 12, 15, 16] as an es- sential tool in heart modeling in order to personalize from

  11. BLACK-BOX MODELLING OF HVAC SYSTEM: IMPROVING THE PERFORMANCES OF NEURAL NETWORKS

    E-Print Network [OSTI]

    Boyer, Edmond

    BLACK-BOX MODELLING OF HVAC SYSTEM: IMPROVING THE PERFORMANCES OF NEURAL NETWORKS Eric FOCK Ile de La Réunion - FRANCE ABSTRACT This paper deals with neural networks modelling of HVAC systems of HVAC system can be modelled using manufacturer design data presented as derived performance maps

  12. Dark Stars: Improved Models and First Pulsation Results

    E-Print Network [OSTI]

    Tanja Rindler-Daller; Michael H. Montgomery; Katherine Freese; Donald E. Winget; Bill Paxton

    2015-01-12T23:59:59.000Z

    We use the stellar evolution code MESA to study dark stars. Dark stars (DSs), which are powered by dark matter (DM) self-annihilation rather than by nuclear fusion, may be the first stars to form in the Universe. We compute stellar models for accreting DSs with masses up to 10^6 M_{sun}. The heating due to DM annihilation is self-consistently included, assuming extended adiabatic contraction of DM within the minihalos in which DSs form. We find remarkably good overall agreement with previous models, which assumed polytropic interiors. There are some differences in the details, with positive implications for observability. We found that, in the mass range of 10^4 -10^5 M_{sun}, our DSs are hotter by a factor of 1.5 than those in Freese et al.(2010), are smaller in radius by a factor of 0.6, denser by a factor of 3 - 4, and more luminous by a factor of 2. Our models also confirm previous results, according to which supermassive DSs are very well approximated by (n=3)-polytropes. We also perform a first study of dark star pulsations. Our DS models have pulsation modes with timescales ranging from less than a day to more than two years in their rest frames, at z ~ 15, depending on DM particle mass and overtone number. Such pulsations may someday be used to identify bright, cool objects uniquely as DSs; if properly calibrated, they might, in principle, also supply novel standard candles for cosmological studies.

  13. Improvements to Nuclear Data and Its Uncertainties by Theoretical Modeling

    SciTech Connect (OSTI)

    Danon, Yaron; Nazarewicz, Witold; Talou, Patrick

    2013-02-18T23:59:59.000Z

    This project addresses three important gaps in existing evaluated nuclear data libraries that represent a significant hindrance against highly advanced modeling and simulation capabilities for the Advanced Fuel Cycle Initiative (AFCI). This project will: Develop advanced theoretical tools to compute prompt fission neutrons and gamma-ray characteristics well beyond average spectra and multiplicity, and produce new evaluated files of U and Pu isotopes, along with some minor actinides; Perform state-of-the-art fission cross-section modeling and calculations using global and microscopic model input parameters, leading to truly predictive fission cross-sections capabilities. Consistent calculations for a suite of Pu isotopes will be performed; Implement innovative data assimilation tools, which will reflect the nuclear data evaluation process much more accurately, and lead to a new generation of uncertainty quantification files. New covariance matrices will be obtained for Pu isotopes and compared to existing ones. The deployment of a fleet of safe and efficient advanced reactors that minimize radiotoxic waste and are proliferation-resistant is a clear and ambitious goal of AFCI. While in the past the design, construction and operation of a reactor were supported through empirical trials, this new phase in nuclear energy production is expected to rely heavily on advanced modeling and simulation capabilities. To be truly successful, a program for advanced simulations of innovative reactors will have to develop advanced multi-physics capabilities, to be run on massively parallel super- computers, and to incorporate adequate and precise underlying physics. And all these areas have to be developed simultaneously to achieve those ambitious goals. Of particular interest are reliable fission cross-section uncertainty estimates (including important correlations) and evaluations of prompt fission neutrons and gamma-ray spectra and uncertainties.

  14. Improvements to building energy usage modeling during early design stages and retrofits

    E-Print Network [OSTI]

    Mandelbaum, Andrew (Andrew Joseph)

    2014-01-01T23:59:59.000Z

    A variety of improvements to the MIT Design Advisor, a whole-building energy usage modeling tool intended for use during early design stages, are investigated. These include changes to the thermal mass temperature distribution ...

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

    SciTech Connect (OSTI)

    Hartin, Corinne A.; Patel, Pralit L.; Schwarber, Adria; Link, Robert P.; Bond-Lamberty, Benjamin

    2015-01-01T23:59:59.000Z

    Simple climate models play an integral role in 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, 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 three main carbon pools: an atmosphere, land, and ocean. The model’s terrestrial carbon cycle includes respiration and primary production, accommodating arbitrary geographic divisions into, e.g., ecological biomes or political units. Hector’s 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] and surface temperatures. The model simulates all four Representative Concentration Pathways with high correlations (R >0.7) with current observations, MAGICC (a well-known simple climate model), and the Coupled Model Intercomparison Project version 5. Hector is freely available under an open source license, and its modular design will facilitate a broad range of research in various areas.

  16. Data Collection for Improved Cold Temperature Thermal Modeling | Department

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page on Google Bookmark EERE: Alternative Fuels DataDepartment of Energy Your Density Isn't Your Destiny:Revised Finding of No53197 This work wasof Energy Modeling Data Collection for

  17. Uncertainty analysis of an aviation climate model and an aircraft price model for assessment of environmental effects

    E-Print Network [OSTI]

    Jun, Mina

    2007-01-01T23:59:59.000Z

    Estimating, presenting, and assessing uncertainties are important parts in assessment of a complex system. This thesis focuses on the assessment of uncertainty in the price module and the climate module in the Aviation ...

  18. Modeling, Analysis, Predictions, and Projections Email: oar.cpo.mapp@noaa.gov

    E-Print Network [OSTI]

    Earth system models to better simulate the climate system? Can we improve intraseasonal to seasonal mission, MAPP supports the development of advanced Earth system models that can predict climate variations, and the external research community. MAPP Objectives · Improve Earth system models · Achieve an integrated Earth

  19. Climate change effects on agriculture: Economic responses to biophysical shocks

    SciTech Connect (OSTI)

    Nelson, Gerald; Valin, Hugo; Sands, Ronald; Havlik, Petr; Ahammad, Helal; Deryng, Delphine; Elliott, Joshua; Fujimori, Shinichiro; Hasegawa, Tomoko; Heyhoe, Edwina; Kyle, G. Page; von Lampe, Martin; Lotze-Campen, Hermann; Mason d'Croz, Daniel; van Meijl, Hans; van der Mensbrugghe, Dominique; Mueller, C.; Popp, Alexander; Robertson, Richard; Robinson, Sherman; Schmid, E.; Schmitz, Christoph; Tabeau, Andrzej; Willenbockel, Dirk

    2013-12-16T23:59:59.000Z

    Agricultural production is sensitive to weather and will thus be directly affected by climate change. Plausible estimates of these climate change impacts require combined use of climate, crop, and economic models. Results from previous studies vary substantially due to differences in models, scenarios, and data. This paper is part of a collective effort to systematically integrate these three types of models. We focus on the economic component of the assessment, investigating how nine global economic models of agriculture represent endogenous responses to seven standardized climate change scenarios produced by two climate and five crop models. These responses include adjustments in yields, area, consumption, and international trade. We apply biophysical shocks derived from the IPCC’s Representative Concentration Pathway that result in end-of-century radiative forcing of 8.5 watts per square meter. The mean biophysical impact on crop yield with no incremental CO2 fertilization is a 17 percent reduction globally by 2050 relative to a scenario with unchanging climate. Endogenous economic responses reduce yield loss to 11 percent, increase area of major crops by 12 percent, and reduce consumption by 2 percent. Agricultural production, cropland area, trade, and prices show the greatest degree of variability in response to climate change, and consumption the lowest. The sources of these differences includes model structure and specification; in particular, model assumptions about ease of land use conversion, intensification, and trade. This study identifies where models disagree on the relative responses to climate shocks and highlights research activities needed to improve the representation of agricultural adaptation responses to climate change.

  20. Climatic trends of the equatorial undercurrent: A backup mechanism for sustaining the equatorial Pacific production

    E-Print Network [OSTI]

    Paparella, Francesco

    in a future climate change scenario, using climate model data from an Earth system model. A selected set

  1. 4, 28752899, 2007 Climate change

    E-Print Network [OSTI]

    Paris-Sud XI, Université de

    HESSD 4, 2875­2899, 2007 Climate change impact and model inaccuracy P. Droogers et al. Title Page are under open-access review for the journal Hydrology and Earth System Sciences Climate change impact­2899, 2007 Climate change impact and model inaccuracy P. Droogers et al. Title Page Abstract Introduction

  2. Improved user interface design for site selection modeling system

    SciTech Connect (OSTI)

    Koffman, L.D. [Westinghouse Savannah River Site, Aiken, SC (United States)

    1996-12-31T23:59:59.000Z

    The Site Selection Modeling System (SSMS) is a customized application within the Environmental Data Atlas (EDA), which is an integrated geographic information system (GIS) for environmental applications at the Savannah River site (SRS) developed jointly by the Environmental Sciences Section (ESS) of Westinghouse Savannah River Company and by the University of South Carolina (USC). The SSMS was developed to assist analysts with site selection activities carried out by the ESS and is a powerful tool with a graphical user interface that allows non-GIS analysts to use the application. However, use of the SSMS in recent siting exercises revealed deficiencies in the user interface as a production tool. This paper specifies user interface design criteria necessary for a production application and describes the implementation of these design criteria in the SSMS.

  3. Sandia National Laboratories: Global Climate & Energy

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    20, 2013, in Advanced Materials Laboratory, Energy Efficiency, Facilities, Global Climate & Energy, Materials Science, Modeling, Modeling & Analysis, Partnership, Research &...

  4. Response of water vapor to interannual variations of SST: Results from NCAR Community Climate Model (CCM2)

    SciTech Connect (OSTI)

    Sun, De-Zheng [National Center For Atmospheric Research, Boulder, CO (United States)

    1997-11-01T23:59:59.000Z

    This paper very briefly documents the response of water vapor to interannual changes in sea surface temperature (SST) in two of the most frequently used climate models: the National Center for Atmospheric Research (NCAR) community climate model (CCM2) and the GFDL spectral model (R30). The corresponding results from radiosonde data are also presented for reference. A simple linear regression model is used to quantify the response of water vapor to changes in SST in the two simulations. Except for the negative response of water vapor over Australia, CCM2 simulates the major characteristics in the horizontal structure of the water vapor response shown in the radiosonde data. The negative response of water over Australia is also not well simulated by GFDL R30. In addition, GFDL R30 significantly underestimates the positive response over the Indian Ocean. The horizontal contrasts between the negative response over the western Pacific and the positive response over the central and eastern Pacific in the model simulations are larger than in the radiosonde data. The negative response in the subtropical region in CCM2 is more pronounced than in R30. Averaged over the tropics, CCM2 has a larger water vapor response in both the boundary layer and the upper troposphere than R30. The correlations between variations of water vapor in the upper troposphere and those at the surface level are also stronger in CCM2 than in R30. 2 refs., 5 figs.

  5. RESIDUA UPGRADING EFFICIENCY IMPROVEMENT MODELS: COKE FORMATION PREDICTABILITY MAPS

    SciTech Connect (OSTI)

    John F. Schabron; A. Troy Pauli; Joseph F. Rovani Jr.

    2002-05-01T23:59:59.000Z

    The dispersed particle solution model of petroleum residua structure was used to develop predictors for pyrolytic coke formation. Coking Indexes were developed in prior years that measure how near a pyrolysis system is to coke formation during the coke formation induction period. These have been demonstrated to be universally applicable for residua regardless of the source of the material. Coking onset is coincidental with the destruction of the ordered structure and the formation of a multiphase system. The amount of coke initially formed appears to be a function of the free solvent volume of the original residua. In the current work, three-dimensional coke make predictability maps were developed at 400 C, 450 C, and 500 C (752 F, 842 F, and 932 F). These relate residence time and free solvent volume to the amount of coke formed at a particular pyrolysis temperature. Activation energies for two apparent types of zero-order coke formation reactions were estimated. The results provide a new tool for ranking residua, gauging proximity to coke formation, and predicting initial coke make tendencies.

  6. An improved model for the transit entropy of monatomic liquids

    SciTech Connect (OSTI)

    Wallace, Duane C [Los Alamos National Laboratory; Chisolm, Eric D [Los Alamos National Laboratory; Bock, Nicolas [Los Alamos National Laboratory

    2009-01-01T23:59:59.000Z

    In the original formulation of V-T theory for monatomic liquid dynamics, the transit contribution to entropy was taken to be a universal constant, calibrated to the constant-volume entropy of melting. This model suffers two deficiencies: (a) it does not account for experimental entropy differences of {+-}2% among elemental liquids, and (b) it implies a value of zero for the transit contribution to internal energy. The purpose of this paper is to correct these deficiencies. To this end, the V-T equation for entropy is fitted to an overall accuracy of {+-}0.1% to the available experimental high temperature entropy data for elemental liquids. The theory contains two nuclear motion contributions: (a) the dominant vibrational contribution S{sub vib}(T/{theta}{sub 0}), where T is temperature and {theta}{sub 0} is the vibrational characteristic temperature, and (b) the transit contribution S{sub tr}(T/{theta}{sub tr}), where {theta}{sub tr} is a scaling temperature for each liquid. The appearance of a common functional form of S{sub tr} for all the liquids studied is a property of the experimental data, when analyzed via the V-T formula. The resulting S{sub tr} implies the correct transit contribution to internal energy. The theoretical entropy of melting is derived, in a single formula applying to normal and anomalous melting alike. An ab initio calculation of {theta}{sub 0}, based on density functional theory, is reported for liquid Na and Cu. Comparison of these calculations with the above analysis of experimental entropy data provides verification of V-T theory. In view of the present results, techniques currently being applied in ab initio simulations of liquid properties can be employed to advantage in the further testing and development of V-T theory.

  7. Polar amplification of climate change in coupled models Received: 21 November 2002 / Accepted: 11 March 2003 / Published online: 17 June 2003

    E-Print Network [OSTI]

    Bitz, Cecilia

    the models. The range of simulated polar warming in the Arctic is from 1.5 to 4.5 times the global mean among models that the Arctic warms more than subpolar regions when subject to increasing levels hemispheres the range of warming across global climate models is considerable, with the range of warm- ing

  8. AN IMPROVED DYNAMIC MODEL FOR THE STUDY OF A FLEXIBLE PAVEMENT

    E-Print Network [OSTI]

    Avignon et des Pays de Vaucluse, Université de

    AN IMPROVED DYNAMIC MODEL FOR THE STUDY OF A FLEXIBLE PAVEMENT A. El Ayadi 1 , B. Picoux 1 , G to study a Falling Weight Deectometer test conducted on a exible pavement. These dynamic models take with in situ measurements recorded on an instrumented pavement; such a comparison has indicated the importance

  9. Improving the Production Efficiency of Beef Cows through Mathematical Modeling and Genomics

    E-Print Network [OSTI]

    Improving the Production Efficiency of Beef Cows through Mathematical Modeling and Genomics that integrating recent advances in genomics, the identification of intrinsic genetic factors that determine and evaluate the individual-based model for production efficiency· of beef cows using genomic and biomarker

  10. A Supply-Demand Model Based Scalable Energy Management System for Improved Energy

    E-Print Network [OSTI]

    Bhunia, Swarup

    energy generation and consumption parameters. The system uses economics inspired supply-demand modelA Supply-Demand Model Based Scalable Energy Management System for Improved Energy Utilization Western Reserve University, *Cleveland State University, +Rockwell Automation, Cleveland, OR, USA Email

  11. The Program for Climate Model Diagnosis and Intercomparison (PCMDI) Software Development: Applications, Infrastructure, and Middleware/Networks

    SciTech Connect (OSTI)

    Williams, Dean N. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)

    2011-06-30T23:59:59.000Z

    The status of and future plans for the Program for Climate Model Diagnosis and Intercomparison (PCMDI) hinge on software that PCMDI is either currently distributing or plans to distribute to the climate community in the near future. These software products include standard conventions, national and international federated infrastructures, and community analysis and visualization tools. This report also mentions other secondary software not necessarily led by or developed at PCMDI to provide a complete picture of the overarching applications, infrastructures, and middleware/networks. Much of the software described anticipates the use of future technologies envisioned over the span of next year to 10 years. These technologies, together with the software, will be the catalyst required to address extreme-scale data warehousing, scalability issues, and service-level requirements for a diverse set of well-known projects essential for predicting climate change. These tools, unlike the previous static analysis tools of the past, will support the co-existence of many users in a productive, shared virtual environment. This advanced technological world driven by extreme-scale computing and the data it generates will increase scientists’ productivity, exploit national and international relationships, and push research to new levels of understanding.

  12. Data Quality Assessment and Control for the ARM Climate Research Facility

    SciTech Connect (OSTI)

    Peppler, R

    2012-06-26T23:59:59.000Z

    The mission of the Atmospheric Radiation Measurement (ARM) Climate Research Facility is to provide observations of the earth climate system to the climate research community for the purpose of improving the understanding and representation, in climate and earth system models, of clouds and aerosols as well as their coupling with the Earth's surface. In order for ARM measurements to be useful toward this goal, it is important that the measurements are of a known and reasonable quality. The ARM data quality program includes several components designed to identify quality issues in near-real-time, track problems to solutions, assess more subtle long-term issues, and communicate problems to the user community.

  13. Modeling Climate Change Policies in Canada and the U.S.: An Update

    E-Print Network [OSTI]

    Roop, J. M.; Tubbs, W. J.

    and describe the major results. Various climate change policy runs were simulated for the both the Canadian and U. S. economies: a U. S. equivalent carbon price of $60 and $120 implemented either slowly or rapidly define the slow-shallow, slow-deep, fast...

  14. Small Residence Multizone Modeling with Partial Conditioning for Energy Effieiency in Hot and Humid Climates

    E-Print Network [OSTI]

    Andolsun, Simge

    2013-07-30T23:59:59.000Z

    The purpose of this study is to reduce the energy cost of the low-income households in the hot and humid climates of the U.S. and thereby to help them afford comfortable homes. In this perspective, a new HVAC energy saving strategy, i.e. “partial...

  15. Small Residence Multizone Modeling with Partial Conditioning for Energy Effieiency in Hot and Humid Climates 

    E-Print Network [OSTI]

    Andolsun, Simge

    2013-07-30T23:59:59.000Z

    The purpose of this study is to reduce the energy cost of the low-income households in the hot and humid climates of the U.S. and thereby to help them afford comfortable homes. In this perspective, a new HVAC energy saving strategy, i.e. “partial...

  16. Coupled Model Intercomparison Project 5 (CMIP5) simulations of climate following volcanic eruptions

    E-Print Network [OSTI]

    Robock, Alan

    the incoming shortwave radiation (SW) and also absorbs solar near infrared (NIR) radiation and upwelling long] For a volcano to have a significant long-term impact on the climate it must inject a sufficient amount of sulfur wave (LW) radiation from the surface and atmosphere below [Stenchikov et al., 1998; Ramachandran et al

  17. LETTER Climate envelope modelling reveals intraspecific relationships among flowering phenology, niche breadth and potential

    E-Print Network [OSTI]

    Purugganan, Michael D.

    Silvia Gerard3 Lucy Chou,4 Amity Wilczek,5 Johanna Schmitt,6 Paula X. Kover7 and Michael D. Purugganan8, in turn, determine its potential range size (Svenning & Skov 2004; Paul et al. 2009). It is generally this information to predict other suitable areas where the species could live (Paul et al. 2009). Climate envelope

  18. Determining Greenland Ice Sheet sensitivity to regional climate change: one-way coupling of a 3-D thermo-mechanical ice sheet model with a mesoscale climate model

    E-Print Network [OSTI]

    Schlegel, Nicole-Jeanne

    2011-01-01T23:59:59.000Z

    in running RCM’s over Greenland to produce high-qualityoutlet glaciers. For Greenland, this detail is specificallyCurrently, no coupled Greenland Ice Sheet model experiment

  19. www.climate.iitb.ac.in 1st CLIMATE SCIENCE AND

    E-Print Network [OSTI]

    Sarawagi, Sunita

    and emissions modeling, Climate mitigation technologies (enhanced carbon capture systems, photoactive materials and technology: Terrestrial carbon sources and sinks, Prediction of climate extremes, Climate perturbation and devices, non-carbon energy technologies, biorefineries, negative net-carbon technologies

  20. Integrated Assessment of Hadley Centre (HadCM2) Climate Change Projections on Agricultural Productivity and Irrigation Water Supply in the Conterminous United States.I. Climate change scenarios and impacts on irrigation water supply simulated with the HUMUS model.

    SciTech Connect (OSTI)

    Rosenberg, Norman J.; Brown, Robert A.; Izaurralde, R Cesar C.; Thomson, Allison M.

    2003-06-30T23:59:59.000Z

    This paper describes methodology and results of a study by researchers at PNNL contributing to the water sector study of the U.S. National Assessment of Climate Change. The vulnerability of water resources in the conterminous U.S. to climate change in 10-y periods centered on 2030 and 2095--as projected by the HadCM2 general circulation model--was modeled with HUMUS (Hydrologic Unit Model of the U.S.). HUMUS consists of a GIS that provides data on soils, land use and climate to drive the hydrology model Soil Water Assessment Tool (SWAT). The modeling was done at the scale of the 2101 8-digit USGS hydrologic unit areas (HUA). Results are aggregated to the 4-digit and 2-digit (Major Water Resource Region, MWRR) scales for various purposes. Daily records of temperature and precipitation for 1961-1990 provided the baseline climate. Water yields (WY)--sum of surface and subsurface runoff--increases from the baseline period over most of the U.S. in 2030 and 2095. In 2030, WY increases in the western US and decreases in the central and southeast regions. Notably, WY increases by 139 mm from baseline in the Pacific NW. Decreased WY is projected for the Lower Mississippi and Texas Gulf basins, driven by higher temperatures and reduced precipitation. The HadCM2 2095 scenario projects a climate significantly wetter than baseline, resulting in WY increases of 38%. WY increases are projected throughout the eastern U.S. WY also increases in the western U.S. Climate change also affects the seasonality of the hydrologic cycle. Early snowmelt is induced in western basins, leading to dramatically increased WYs in late winter and early spring. The simulations were run at current (365 ppm) and elevated (560 ppm) atmospheric CO2 concentrations to account for the potential impacts of the CO2-fertilization effect. The effects of climate change scenario were considerably greater than those due to elevated CO2 but the latter, overall, decreased losses and augmented increases in water yield.

  1. Detection of CO sub 2 -induced climatic change

    SciTech Connect (OSTI)

    Wigley, T.M.L.

    1990-07-15T23:59:59.000Z

    In spite of the strong circumstantial evidence that the greenhouse effect has contributed significantly to the observed global warming, we are still unable to state unequivocally that the effect has been detected. Either we must eliminate all other possibilities, or we must identify one or more multivariate characteristics of the observed changes in climate that are unique signature of the greenhouse effect. We propose to continue earlier work in five areas: Updating, improvement and analysis of our global (land and marine) temperature data set, The development and use of multivariate techniques for the detection of greenhouse-gas-induced climatic change, The further development and use of simple transient-response climate models in order to elucidate the responses of the climate system to external and internal forcing, Validation of General Circulation Models using a variety of test statistics, and The use of regression methods to produce sub-grid-scale information from GCM output. 63 refs., 2 figs., 1 tab.

  2. Simulated diurnal rainfall physics in a multi-scale global climate model with embedded explicit convection

    E-Print Network [OSTI]

    Pritchard, Michael Stephen

    2011-01-01T23:59:59.000Z

    their Community Earth System Model (Richard Neale, personaldevelopment of Earth system models capable of reproducing

  3. Ecosystem feedbacks to climate change in California: Development, testing, and analysis using a coupled regional atmosphere and land-surface model (WRF3-CLM3.5)

    SciTech Connect (OSTI)

    Subin, Z.M.; Riley, W.J.; Kueppers, L.M.; Jin, J.; Christianson, D.S.; Torn, M.S.

    2010-11-01T23:59:59.000Z

    A regional atmosphere model [Weather Research and Forecasting model version 3 (WRF3)] and a land surface model [Community Land Model, version 3.5 (CLM3.5)] were coupled to study the interactions between the atmosphere and possible future California land-cover changes. The impact was evaluated on California's climate of changes in natural vegetation under climate change and of intentional afforestation. The ability of WRF3 to simulate California's climate was assessed by comparing simulations by WRF3-CLM3.5 and WRF3-Noah to observations from 1982 to 1991. Using WRF3-CLM3.5, the authors performed six 13-yr experiments using historical and future large-scale climate boundary conditions from the Geophysical Fluid Dynamics Laboratory Climate Model version 2.1 (GFDL CM2.1). The land-cover scenarios included historical and future natural vegetation from the Mapped Atmosphere-Plant-Soil System-Century 1 (MC1) dynamic vegetation model, in addition to a future 8-million-ha California afforestation scenario. Natural vegetation changes alone caused summer daily-mean 2-m air temperature changes of -0.7 to +1 C in regions without persistent snow cover, depending on the location and the type of vegetation change. Vegetation temperature changes were much larger than the 2-m air temperature changes because of the finescale spatial heterogeneity of the imposed vegetation change. Up to 30% of the magnitude of the summer daily-mean 2-m air temperature increase and 70% of the magnitude of the 1600 local time (LT) vegetation temperature increase projected under future climate change were attributable to the climate-driven shift in land cover. The authors projected that afforestation could cause local 0.2-1.2 C reductions in summer daily-mean 2-m air temperature and 2.0-3.7 C reductions in 1600 LT vegetation temperature for snow-free regions, primarily because of increased evapotranspiration. Because some of these temperature changes are of comparable magnitude to those projected under climate change this century, projections of climate and vegetation change in this region need to consider these climate-vegetation interactions.

  4. he Impact of Primary Marine Aerosol on Atmospheric Chemistry, Radiation and Climate: A CCSM Model Development Study

    SciTech Connect (OSTI)

    Keene, William C. [University of Virginia] [University of Virginia; Long, Michael S. [University of Virginia] [University of Virginia

    2013-05-20T23:59:59.000Z

    This project examined the potential large-scale influence of marine aerosol cycling on atmospheric chemistry, physics and radiative transfer. Measurements indicate that the size-dependent generation of marine aerosols by wind waves at the ocean surface and the subsequent production and cycling of halogen-radicals are important but poorly constrained processes that influence climate regionally and globally. A reliable capacity to examine the role of marine aerosol in the global-scale atmospheric system requires that the important size-resolved chemical processes be treated explicitly. But the treatment of multiphase chemistry across the breadth of chemical scenarios encountered throughout the atmosphere is sensitive to the initial conditions and the precision of the solution method. This study examined this sensitivity, constrained it using high-resolution laboratory and field measurements, and deployed it in a coupled chemical-microphysical 3-D atmosphere model. First, laboratory measurements of fresh, unreacted marine aerosol were used to formulate a sea-state based marine aerosol source parameterization that captured the initial organic, inorganic, and physical conditions of the aerosol population. Second, a multiphase chemical mechanism, solved using the Max Planck Institute for Chemistryâ??s MECCA (Module Efficiently Calculating the Chemistry of the Atmosphere) system, was benchmarked across a broad set of observed chemical and physical conditions in the marine atmosphere. Using these results, the mechanism was systematically reduced to maximize computational speed. Finally, the mechanism was coupled to the 3-mode modal aerosol version of the NCAR Community Atmosphere Model (CAM v3.6.33). Decadal-scale simulations with CAM v.3.6.33, were run both with and without reactive-halogen chemistry and with and without explicit treatment of particulate organic carbon in the marine aerosol source function. Simulated results were interpreted (1) to evaluate influences of marine aerosol production on the microphysical properties of aerosol populations and clouds over the ocean and the corresponding direct and indirect effects on radiative transfer; (2) atmospheric burdens of reactive halogen species and their impacts on O3, NOx, OH, DMS, and particulate non-sea-salt SO42-; and (3) the global production and influences of marine-derived particulate organic carbon. The model reproduced major characteristics of the marine aerosol system and demonstrated the potential sensitivity of global, decadal-scale climate metrics to multiphase marine-derived components of Earthâ??s troposphere. Due to the combined computational burden of the coupled system, the currently available computational resources were the limiting factor preventing the adequate statistical analysis of the overall impact that multiphase chemistry might have on climate-scale radiative transfer and climate.

  5. CLIMATE CHANGE IMPACTS, VULNERABILITIES, AND

    E-Print Network [OSTI]

    CLIMATE CHANGE IMPACTS, VULNERABILITIES, AND ADAPTATION IN THE SAN FRANCISCO BAY AREA Commission's California Climate Change Center JULY 2012 CEC5002012071 Prepared for: California Energy, as well as projections of future changes in climate based on modeling studies using various plausible

  6. Climate shocks: Natural and anthropogenic

    SciTech Connect (OSTI)

    Kondratyev, K.Ya.

    1988-01-01T23:59:59.000Z

    Much recent climate research has focused on the effects of CO{sub 2} and radiatively important trace species, volcanic eruptions, and nuclear exchanges on our future climate. These studies suggest that anthropogenic influence will alter our present climate. The reliability of the climate models are a subject of debate, yet valid information derived from climate models is critical for policy-makers and politicians to make decisions regarding energy use and development and defense strategies. K.Ya. Kondratyev, a leading Soviet climate scientist, addresses the role of the greenhouse effect, nuclear winter, and volcanic eruptions on our climate in a recently published book entitled Climate Shocks: Natural and Anthropogenic. The book provides a detailed survey of the literature on these fields, including the pertinent Soviet literature that is often not surveyed by Western scientists.

  7. Climate Change: The Physical Basis and Latest Results

    ScienceCinema (OSTI)

    None

    2011-10-06T23:59:59.000Z

    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 global climate change challenge.

  8. Atmospheric Radiation Measurement Climate Research Facility (ACRF) Annual Report 2008

    SciTech Connect (OSTI)

    LR Roeder

    2008-12-01T23:59:59.000Z

    The Importance of Clouds and Radiation for Climate Change: The Earth’s surface temperature is determined by the balance between incoming solar radiation and thermal (or infrared) radiation emitted by the Earth back to space. Changes in atmospheric composition, including greenhouse gases, clouds, and aerosols, can alter this balance and produce significant climate change. Global climate models (GCMs) are the primary tool for quantifying future climate change; however, there remain significant uncertainties in the GCM treatment of clouds, aerosol, and their effects on the Earth’s energy balance. In 1989, the U.S. Department of Energy (DOE) Office of Science created the Atmospheric Radiation Measurement (ARM) Program to address scientific uncertainties related to global climate change, with a specific focus on the crucial role of clouds and their influence on the transfer of radiation in the atmosphere. To reduce these scientific uncertainties, the ARM Program uses a unique twopronged approach: • The ARM Climate Research Facility, a scientific user facility for obtaining long-term measurements of radiative fluxes, cloud and aerosol properties, and related atmospheric characteristics in diverse climate regimes; and • The ARM Science Program, focused on the analysis of ACRF and other data to address climate science issues associated with clouds, aerosols, and radiation, and to improve GCMs. This report provides an overview of each of these components and a sample of achievements for each in fiscal year (FY) 2008.

  9. Potential impacts of climate change on tropospheric ozone in California: a preliminary episodic modeling assessment of the Los Angeles basin and the Sacramento valley

    SciTech Connect (OSTI)

    Taha, Haider

    2001-01-01T23:59:59.000Z

    In this preliminary and relatively short modeling effort, an initial assessment is made for the potential air quality implications of climate change in California. The focus is mainly on the effects of changes in temperature and related meteorological and emission factors on ozone formation. Photochemical modeling is performed for two areas in the state: the Los Angeles Basin and the Sacramento Valley.

  10. Improvement of capabilities of the Distributed Electrochemistry Modeling Tool for investigating SOFC long term performance

    SciTech Connect (OSTI)

    Gonzalez Galdamez, Rinaldo A.; Recknagle, Kurtis P.

    2012-04-30T23:59:59.000Z

    This report provides an overview of the work performed for Solid Oxide Fuel Cell (SOFC) modeling during the 2012 Winter/Spring Science Undergraduate Laboratory Internship at Pacific Northwest National Laboratory (PNNL). A brief introduction on the concept, operation basics and applications of fuel cells is given for the general audience. Further details are given regarding the modifications and improvements of the Distributed Electrochemistry (DEC) Modeling tool developed by PNNL engineers to model SOFC long term performance. Within this analysis, a literature review on anode degradation mechanisms is explained and future plans of implementing these into the DEC modeling tool are also proposed.

  11. Development and application of WRF3.3-CLM4crop to study of agriculture - climate interaction

    E-Print Network [OSTI]

    Lu, Yaqiong

    2013-01-01T23:59:59.000Z

    Global Climate Change and United-States Agriculture, Nature,climate modeling Land surface modeling Agriculture and climate interaction Land use change

  12. Comparison of "warm and wet" and "cold and icy" scenarios for early Mars in a 3D climate model

    E-Print Network [OSTI]

    Wordsworth, Robin D; Pierrehumbert, Raymond T; Forget, Francois; Head, James W

    2015-01-01T23:59:59.000Z

    We use a 3D general circulation model to compare the primitive Martian hydrological cycle in "warm and wet" and "cold and icy" scenarios. In the warm and wet scenario, an anomalously high solar flux or intense greenhouse warming artificially added to the climate model are required to maintain warm conditions and an ice-free northern ocean. Precipitation shows strong surface variations, with high rates around Hellas basin and west of Tharsis but low rates around Margaritifer Sinus (where the observed valley network drainage density is nonetheless high). In the cold and icy scenario, snow migration is a function of both obliquity and surface pressure, and limited episodic melting is possible through combinations of seasonal, volcanic and impact forcing. At surface pressures above those required to avoid atmospheric collapse (~0.5 bar) and moderate to high obliquity, snow is transported to the equatorial highland regions where the concentration of valley networks is highest. Snow accumulation in the Aeolis quadr...

  13. An improved Reynolds-equation model for gas damping of microbeam motion.

    SciTech Connect (OSTI)

    Gallis, Michail A.; Torczynski, John Robert

    2003-09-01T23:59:59.000Z

    An improved gas-damping model for the out-of-plane motion of a near-substrate microbeam is developed based on the Reynolds equation (RE). A boundary condition for the RE is developed that relates the pressure at the beam edge to the beam motion. The coefficients in this boundary condition are determined from Navier-Stokes slip-jump (NSSJ) simulations for small slip lengths (relative to the gap height) and from direct simulation Monte Carlo (DSMC) molecular gas dynamics simulations for larger slip lengths. This boundary condition significantly improves the accuracy of the RE when the microbeam width is only slightly greater than the gap height between the microbeam and the substrate. The improved RE model is applied to microbeams fabricated using the SUMMiT V process.

  14. Aerosol–climate interactions in the Norwegian Earth System Model – NorESM1-M

    SciTech Connect (OSTI)

    Kirkevag, A.; Iversen, T.; Seland, O.; Hoose, C.; Kristjansson, J. E.; Struthers, H.; Ekman, A. M.; Ghan, Steven J.; Griesfeller, Jan; Nilsson, E. D.; Schulz, M.

    2013-02-08T23:59:59.000Z

    The objective of this study is to document and evaluate recent changes and updates to the module for aerosols and aerosol–cloud–radiation interactions in the atmospheric module CAM4-Oslo of the core version of the Norwegian Earth System Model (NorESM), NorESM1-M. Particular attention is paid to the role of natural organics, sea salt, and mineral dust in determining the gross aerosol properties as well as the anthropogenic contribution to these properties and the associated direct and indirect radiative forcing. The aerosol module is extended from earlier versions that have been published, and includes life-cycling of sea salt, mineral dust, particulate sulphate, black carbon, and primary and secondary organics. The impacts of most of the numerous changes since previous versions are thoroughly explored by sensitivity experiments. The most important changes are: modified prognostic sea salt emissions; updated treatment of precipitation scavenging and gravitational settling; inclusion of biogenic primary organics and methane sulphonic acid (MSA) from oceans; almost doubled production of land-based biogenic secondary organic aerosols (SOA); and increased ratio of organic matter to organic carbon (OM/OC) for biomass burning aerosols from 1.4 to 2.6. Compared with in situ measurements and remotely sensed data, the new treatments of sea salt and dust aerosols give smaller biases in near-surface mass concentrations and aerosol optical depth than in the earlier model version. The model biases for mass concentrations are approximately unchanged for sulphate and BC. The enhanced levels of modeled OM yield improved overall statistics, even though OM is still underestimated in Europe and overestimated in North America. The global anthropogenic aerosol direct radiative forcing (DRF) at the top of the atmosphere has changed from a small positive value to ?0.08 W m?2 in CAM4-Oslo. The sensitivity tests suggest that this change can be attributed to the new treatment of biomass burning aerosols and gravitational settling. Although it has not been a goal in this study, the new DRF estimate is closer both to the median model estimate from the AeroCom intercomparison and the best estimate in IPCC AR4. Estimated DRF at the ground surface has increased by ca. 60%, to ?1.89 W m?2. We show that this can be explained by new emission data and omitted mixing of constituents between updrafts and downdrafts in convective clouds. The increased abundance of natural OM and the introduction of a cloud droplet spectral dispersion formulation are the most important contributions to a considerably decreased estimate of the indirect radiative forcing (IndRF). The IndRF is also found to be sensitive to assumptions about the coating of insoluble aerosols by sulphate and OM. The IndRF of ?1.2 W m?2, which is closer to the IPCC AR4 estimates than the previous estimate of ?1.9 W m?2, has thus been obtained without imposing unrealistic artificial lower bounds on cloud droplet number concentrations.

  15. USING TIME-LAPSE SEISMIC MEASUREMENTS TO IMPROVE FLOW MODELING OF CO2 INJECTION

    E-Print Network [OSTI]

    Marly. The EOR process in the RCP section of the Weyburn Field uses CO2 and water injection to displaceUSING TIME-LAPSE SEISMIC MEASUREMENTS TO IMPROVE FLOW MODELING OF CO2 INJECTION IN THE WEYBURN, particularly CO2. Time lapse seismic monitoring has motivated changes to the reservoir description in a flow

  16. Resveratrol Improves Survival, Hemodynamics and Energetics in a Rat Model of Hypertension Leading to

    E-Print Network [OSTI]

    Paris-Sud XI, Université de

    Resveratrol Improves Survival, Hemodynamics and Energetics in a Rat Model of Hypertension Leading and vascular function as well as cardiac and skeletal muscle energy metabolism were assessed in a hypertensive/kg/day; HS-RSV) was given for 8 weeks after hypertension and cardiac hypertrophy were established (which

  17. Hands-On and Minds-On Modeling Activities to Improve Students' Conceptions of Microscopic Friction

    E-Print Network [OSTI]

    Zollman, Dean

    Hands-On and Minds-On Modeling Activities to Improve Students' Conceptions of Microscopic Friction of microscopic friction. We will also present our investigation on the relative effectiveness of the use, it is possible to facilitate the refinement of students' ideas of microscopic friction. Keywords: friction

  18. Improvements on FFD Modeling by Using Different Numerical Schemes Wangda Zuo, Jianjun Hu, Qingyan Chen

    E-Print Network [OSTI]

    Chen, Qingyan "Yan"

    . "Improvements on FFD modeling by using different numerical schemes," Numerical Heat Transfer, Part B (m) t time step (s) Greek Symbols ratio of mass flow rate to a flow domain over that out of the flow: Fundamentals, 58(1), 1-16. #12;2 Abstract Indoor environm ent design and air m anagement in buildings requires

  19. Mathematical Modeling of Carbon Dioxide Injection in the Subsurface for Improved Hydrocarbon Recovery and Sequestration

    E-Print Network [OSTI]

    Firoozabadi, Abbas

    Mathematical Modeling of Carbon Dioxide Injection in the Subsurface for Improved Hydrocarbon Recovery and Sequestration Philip C. Myint, Laurence Rongy, Kjetil B. Haugen, Abbas Firoozabadi Department. Combustion of fossil fuels contributes to rising atmospheric carbon dioxide (CO2) levels that have been

  20. IMPROVED SEMI-PARAMETRIC TIME SERIES MODELS OF AIR POLLUTION AND MORTALITY

    E-Print Network [OSTI]

    Dominici, Francesca

    IMPROVED SEMI-PARAMETRIC TIME SERIES MODELS OF AIR POLLUTION AND MORTALITY Francesca Dominici series analyses of air pollution and health attracted the attention of the scientific community, policy makers, the press, and the diverse stakeholders con- cerned with air pollution. As the Environmental

  1. A Lagrangian subgridscale model for particle transport improvement and application in the Adriatic Sea

    E-Print Network [OSTI]

    Ozgökmen, Tamay M.

    such as dispersion of pollutants, biological species, and sediments. Forecasting of the Lagrangian pathways of the dispersion of pollutants, biological species, and sediments. At the basis of such applications is the transA Lagrangian subgridscale model for particle transport improvement and application in the Adriatic

  2. ReseaRch at the University of Maryland Climate Modeling and Prediction

    E-Print Network [OSTI]

    Hill, Wendell T.

    for farmers and agricultural policy makers Antonio Busalacchi studies tropical ocean circulation to refine, and drought. Eugenia Kalnay uses chaos theory to improve weather forecasting. She also documents land to predict the complex atmospheric effects of polar ice loss. Improving Rainfall Forecasts for Farmers Rapid

  3. Iterative-build OMIT maps: map improvement by iterative model building and refinement without model bias

    SciTech Connect (OSTI)

    Terwilliger, Thomas C., E-mail: terwilliger@lanl.gov [Los Alamos National Laboratory, Los Alamos, NM 87545 (United States); Grosse-Kunstleve, Ralf W.; Afonine, Pavel V.; Moriarty, Nigel W.; Adams, Paul D. [Lawrence Berkeley National Laboratory, One Cyclotron Road, Building 64R0121, Berkeley, CA 94720 (United States); Read, Randy J. [Department of Haematology, University of Cambridge, Cambridge CB2 0XY (United Kingdom); Zwart, Peter H. [Lawrence Berkeley National Laboratory, One Cyclotron Road, Building 64R0121, Berkeley, CA 94720 (United States); Hung, Li-Wei [Los Alamos National Laboratory, Los Alamos, NM 87545 (United States)

    2008-05-01T23:59:59.000Z

    An OMIT procedure is presented that has the benefits of iterative model building density modification and refinement yet is essentially unbiased by the atomic model that is built. A procedure for carrying out iterative model building, density modification and refinement is presented in which the density in an OMIT region is essentially unbiased by an atomic model. Density from a set of overlapping OMIT regions can be combined to create a composite ‘iterative-build’ OMIT map that is everywhere unbiased by an atomic model but also everywhere benefiting from the model-based information present elsewhere in the unit cell. The procedure may have applications in the validation of specific features in atomic models as well as in overall model validation. The procedure is demonstrated with a molecular-replacement structure and with an experimentally phased structure and a variation on the method is demonstrated by removing model bias from a structure from the Protein Data Bank.

  4. On an improved sub-regional water resources management representation for integration into earth system models

    SciTech Connect (OSTI)

    Voisin, Nathalie; Li, Hongyi; Ward, Duane L.; Huang, Maoyi; Wigmosta, Mark S.; Leung, Lai-Yung R.

    2013-09-30T23:59:59.000Z

    Human influence on the hydrologic cycle includes regulation and storage, consumptive use and overall redistribution of water resources in space and time. Representing these processes is essential for applications of earth system models in hydrologic and climate predictions, as well as impact studies at regional to global scales. Emerging large-scale research reservoir models use generic operating rules that are flexible for coupling with earth system models. Those generic operating rules have been successful in reproducing the overall regulated flow at large basin scales. This study investigates the uncertainties of the reservoir models from different implementations of the generic operating rules using the complex multi-objective Columbia River Regulation System in northwestern United States as an example to understand their effects on not only regulated flow but also reservoir storage and fraction of the demand that is met. Numerical experiments are designed to test new generic operating rules that combine storage and releases targets for multi-purpose reservoirs and to compare the use of reservoir usage priorities, withdrawals vs. consumptive demand, as well as natural vs. regulated mean flow for calibrating operating rules. Overall the best performing implementation is the use of the combined priorities (flood control storage targets and irrigation release targets) operating rules calibrated with mean annual natural flow and mean monthly withdrawals. The challenge of not accounting for groundwater withdrawals, or on the contrary, assuming that all remaining demand is met through groundwater extractions, is discussed.

  5. Role of the stratosphere in Northern winter climate change as simulated by the1 CMIP5 models2

    E-Print Network [OSTI]

    Gerber, Edwin

    1 Role of the stratosphere in Northern winter climate change as simulated by the1 CMIP5; 3 Abstract39 40 Stratospheric climate change and its potential for surface climate change Studies, NASA, New York, USA34 (20) Institute of Numerical Mathematics, Moscow, Russia35 (21) Japan

  6. Improvement plans for the RHIC/AGS on-line model environments

    SciTech Connect (OSTI)

    Brown,K.A.; Ahrens, L.; Beebe-Wang, J.; Morris, J.; Nemesure, S.; Robert-Demolaize, G.; Satogata, T.; Schoefer, V.; Tepikian, S.

    2009-08-31T23:59:59.000Z

    The on-line models for Relativistic Ion Collider (RHIC) and the RHIC pre-injectors (the AGS and the AGS Booster) can be thought of as containing our best collective knowledge of these accelerators. As we improve these on-line models we are building the framework to have a sophisticated model-based controls system. Currently the RHIC on-line model is an integral part of the controls system, providing the interface for tune control, chromaticity control, and non-linear chromaticity control. What we discuss in this paper is our vision of the future of the on-line model environment for RHIC and the RHIC preinjectors. Although these on-line models are primarily used as Courant-Snyder parameter calculators using live machine settings, we envision expanding these environments to encompass many other problem domains.

  7. NREL Reduces Climate Control Loads in Electric Vehicles (Fact Sheet)

    SciTech Connect (OSTI)

    Not Available

    2014-08-01T23:59:59.000Z

    NREL demonstrates that zonal climate control can reduce air conditioning power and improve range while maintaining driver thermal sensation.

  8. 2, 11551186, 2006 Mid-Holocene climate

    E-Print Network [OSTI]

    Boyer, Edmond

    CPD 2, 1155­1186, 2006 Mid-Holocene climate change in Europe: a data-model comparison S. Brewer et.clim-past-discuss.net/2/1155/2006/ © Author(s) 2006. This work is licensed under a Creative Commons License. Climate of the Past Discussions Climate of the Past Discussions is the access reviewed discussion forum of Climate

  9. Developing shrub fire behaviour models in an oceanic climate: Burning in the British Uplands 

    E-Print Network [OSTI]

    Davies, Gwilym Matthew; Legg, Colin; Smith, Adam; MacDonald, Angus

    2006-01-01T23:59:59.000Z

    Prescribed burning of moorland vegetation in the UK is used to provide habitat for red grouse, a game bird, and to improve grazing for sheep and deer. The peak time of fire risk corresponds to the normal legal burning ...

  10. Test models for improving filtering with model errors through stochastic parameter estimation

    SciTech Connect (OSTI)

    Gershgorin, B. [Department of Mathematics and Center for Atmosphere and Ocean Science, Courant Institute of Mathematical Sciences, New York University, NY 10012 (United States); Harlim, J. [Department of Mathematics, North Carolina State University, NC 27695 (United States)], E-mail: jharlim@ncsu.edu; Majda, A.J. [Department of Mathematics and Center for Atmosphere and Ocean Science, Courant Institute of Mathematical Sciences, New York University, NY 10012 (United States)

    2010-01-01T23:59:59.000Z

    The filtering skill for turbulent signals from nature is often limited by model errors created by utilizing an imperfect model for filtering. Updating the parameters in the imperfect model through stochastic parameter estimation is one way to increase filtering skill and model performance. Here a suite of stringent test models for filtering with stochastic parameter estimation is developed based on the Stochastic Parameterization Extended Kalman Filter (SPEKF). These new SPEKF-algorithms systematically correct both multiplicative and additive biases and involve exact formulas for propagating the mean and covariance including the parameters in the test model. A comprehensive study is presented of robust parameter regimes for increasing filtering skill through stochastic parameter estimation for turbulent signals as the observation time and observation noise are varied and even when the forcing is incorrectly specified. The results here provide useful guidelines for filtering turbulent signals in more complex systems with significant model errors.

  11. Iterative build OMIT maps: Map improvement by iterative model-building and refinement without model bias

    SciTech Connect (OSTI)

    Los Alamos National Laboratory, Mailstop M888, Los Alamos, NM 87545, USA; Lawrence Berkeley National Laboratory, One Cyclotron Road, Building 64R0121, Berkeley, CA 94720, USA; Department of Haematology, University of Cambridge, Cambridge CB2 0XY, England; Terwilliger, Thomas; Terwilliger, T.C.; Grosse-Kunstleve, Ralf Wilhelm; Afonine, P.V.; Moriarty, N.W.; Zwart, P.H.; Hung, L.-W.; Read, R.J.; Adams, P.D.

    2008-02-12T23:59:59.000Z

    A procedure for carrying out iterative model-building, density modification and refinement is presented in which the density in an OMIT region is essentially unbiased by an atomic model. Density from a set of overlapping OMIT regions can be combined to create a composite 'Iterative-Build' OMIT map that is everywhere unbiased by an atomic model but also everywhere benefiting from the model-based information present elsewhere in the unit cell. The procedure may have applications in the validation of specific features in atomic models as well as in overall model validation. The procedure is demonstrated with a molecular replacement structure and with an experimentally-phased structure, and a variation on the method is demonstrated by removing model bias from a structure from the Protein Data Bank.

  12. Incorporating Urban Systems in Global Climate Models: The Role of GIScience

    E-Print Network [OSTI]

    Feddema, Johannes J.

    2006-11-15T23:59:59.000Z

    0.92 brick 0.7 1360.0 0.3 1700 800 0.9 mud 1.0 1456.0 0.3 1820 800 0.9 wood 0.1 1127.5 0.5 550 2050 0.87 glass 0.9 2100.0 0.08 2500 840 0.91 stone 2.6 2310.0 0.275 2750 840 0.92 adobe 1.0 1456.0 0.3 1820 800 0.91 rubble 0.8 950 0.275 1900 500 0..., Cooperative Agreement No. DE-FC02- 97ER62402, by the National Science Foundation grant numbers ATM-0107404, and ATM-0413540, the NCAR Weather and Climate Impact Assessment Science Initiative, and the University of Kansas, Center for Research. Motivation...

  13. Atmospheric Radiation Measurement Climate Research Facility ...

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    improving our understanding of how clouds and atmospheric moisture interact with solar radiation and the effects of these interactions on climate. Photo courtesy Argonne National...

  14. Validating a physics-based back-of-the-envelope climate model with state-of-the-art data

    E-Print Network [OSTI]

    Benestad, Rasmus E

    2013-01-01T23:59:59.000Z

    An old conceptual physics-based back-of-the-envelope model for greenhouse effect is revisited and validated against state-of-the-art reanalyses. Untraditional diagnostics show a physically consistent picture, for which the state of earth's climate is constrained by well-known physical principles, such as energy balance, flow and, conservation. Greenhouse gas concentrations affect the atmospheric optical depth for infrared radiation, and increased opacity implies higher altitude from which earth's equivalent bulk heat loss takes place without being re-absorbed. Such increase is seen in the reanalyses. There has also been a reduction in the correlation between the spatial structure of outgoing long-wave radiation and surface temperature, consistent with increasingly more processes interfering with the upwelling infrared light before it reaches the top of the atmosphere. State-of-the-art reanalyses further imply increases in the overturning in the troposphere, consistent with a constant and continuous vertical e...

  15. Improving macromolecular atomic models at moderate resolution by automated iterative model building, statistical density modification and refinement

    SciTech Connect (OSTI)

    Terwilliger, Thomas C., E-mail: terwilliger@lanl.gov [Mail Stop M888, Los Alamos National Laboratory, Los Alamos, NM 87545 (United States)

    2003-07-01T23:59:59.000Z

    A procedure for iterative model-building, statistical density modification and refinement at moderate resolution (up to about 2.8 Å) is described. An iterative process for improving the completeness and quality of atomic models automatically built at moderate resolution (up to about 2.8 Å) is described. The process consists of cycles of model building interspersed with cycles of refinement and combining phase information from the model with experimental phase information (if any) using statistical density modification. The process can lead to substantial improvements in both the accuracy and completeness of the model compared with a single cycle of model building. For eight test cases solved by MAD or SAD at resolutions ranging from 2.0 to 2.8 Å, the fraction of models built and assigned to sequence was 46–91% (mean of 65%) after the first cycle of building and refinement, and 78-95% (mean of 87%) after 20 cycles. In an additional test case, an incorrect model of gene 5 protein (PDB code 2gn5; r.m.s.d. of main-chain atoms from the more recent refined structure 1vqb at 1.56 Å) was rebuilt using only structure-factor amplitude information at varying resolutions from 2.0 to 3.0 Å. Rebuilding was effective at resolutions up to about 2.5 Å. The resulting models had 60-80% of the residues built and an r.m.s.d. of main-chain atoms from the refined structure of 0.20 to 0.62 Å. The algorithm is useful for building preliminary models of macromolecules suitable for an experienced crystallographer to extend, correct and fully refine.

  16. Late Holocene Climate Change on Isla Isabela, Gulf of California

    E-Print Network [OSTI]

    Englebrecht, Amy

    2010-01-01T23:59:59.000Z

    solar activity on climate variations remains unclear, this data represents a convergence of model output

  17. Improved Formulations for Air-Surface Exchanges Related to National Security Needs: Dry Deposition Models

    SciTech Connect (OSTI)

    Droppo, James G.

    2006-07-01T23:59:59.000Z

    The Department of Homeland Security and others rely on results from atmospheric dispersion models for threat evaluation, event management, and post-event analyses. The ability to simulate dry deposition rates is a crucial part of our emergency preparedness capabilities. Deposited materials pose potential hazards from radioactive shine, inhalation, and ingestion pathways. A reliable characterization of these potential exposures is critical for management and mitigation of these hazards. A review of the current status of dry deposition formulations used in these atmospheric dispersion models was conducted. The formulations for dry deposition of particulate materials from am event such as a radiological attack involving a Radiological Detonation Device (RDD) is considered. The results of this effort are applicable to current emergency preparedness capabilities such as are deployed in the Interagency Modeling and Atmospheric Assessment Center (IMAAC), other similar national/regional emergency response systems, and standalone emergency response models. The review concludes that dry deposition formulations need to consider the full range of particle sizes including: 1) the accumulation mode range (0.1 to 1 micron diameter) and its minimum in deposition velocity, 2) smaller particles (less than .01 micron diameter) deposited mainly by molecular diffusion, 3) 10 to 50 micron diameter particles deposited mainly by impaction and gravitational settling, and 4) larger particles (greater than 100 micron diameter) deposited mainly by gravitational settling. The effects of the local turbulence intensity, particle characteristics, and surface element properties must also be addressed in the formulations. Specific areas for improvements in the dry deposition formulations are 1) capability of simulating near-field dry deposition patterns, 2) capability of addressing the full range of potential particle properties, 3) incorporation of particle surface retention/rebound processes, and. 4) development of dry deposition formulations applicable to urban areas. Also to improve dry deposition modeling capabilities, atmospheric dispersion models in which the dry deposition formulations are imbedded need better source-term plume initialization and improved in-plume treatment of particle growth processes. Dry deposition formulations used in current models are largely inapplicable to the complex urban environment. An improved capability is urgently needed to provide surface-specific information to assess local exposure hazard levels in both urban and non-urban areas on roads, buildings, crops, rivers, etc. A model improvement plan is developed with a near-term and far-term component. Despite some conceptual limitations, the current formulations for particle deposition based on a resistance approach have proven to provide reasonable dry deposition simulations. For many models with inadequate dry deposition formulations, adding or improving a resistance approach will be the desirable near-term update. Resistance models however are inapplicable aerodynamically very rough surfaces such as urban areas. In the longer term an improved parameterization of dry deposition needs to be developed that will be applicable to all surfaces, and in particular urban surfaces.

  18. Modeling Sea Ice-Ocean-Ecosystem Responses to Climate Changes in the Bering-Chukchi-Beaufort Seas with Data Assimilation of

    E-Print Network [OSTI]

    of Marine Science and Technology, Haoguo Hu - CILER, University of Michigan Overview This project will useModeling Sea Ice-Ocean-Ecosystem Responses to Climate Changes in the Bering-Chukchi-Beaufort Seas-Investigators: Leo Oey - Princeton University, Tel Ezer - Old Dominion University, K. Mizobata - Tokyo University

  19. Simulating the connections of ENSO and the rainfall regime of East Africa and the upper Blue Nile region using a climate model of the Tropics

    E-Print Network [OSTI]

    Zaroug, M. A. H.

    We simulate the observed statistical relationship between ENSO and the rainfall regime of the upper Blue Nile using the tropical-band version of the regional climate model RegCM4 (or Reg-TB). An ensemble of nine simulations ...

  20. THE IDENTIFICATION OF A SOLAR SIGNAL IN CLIMATE RECORDS OF THE LAST 500 YEARS USING PROXY AND MODEL-BASED ANALYSIS AND

    E-Print Network [OSTI]

    Massachusetts at Amherst, University of

    for their help with acquiring solar data and figures, as well as helping me to interpret them. Jay Lawrimore there is no consensus as to the best method for estimating past variations in solar output, it seems likely that overTHE IDENTIFICATION OF A SOLAR SIGNAL IN CLIMATE RECORDS OF THE LAST 500 YEARS USING PROXY AND MODEL