National Library of Energy BETA

Sample records for improve climate models

  1. Improvement of snowpack simulations in a regional climate model

    SciTech Connect (OSTI)

    Jin, J.; Miller, N.L.

    2011-01-10

    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 FUTURE CLIMATE PREDICTION USING

    E-Print Network [OSTI]

    Henderson, Gideon

    IMPROVING FUTURE CLIMATE PREDICTION USING PALAEOCLIMATE DATA A community White Paper for consideration by the Natural Environment Research Council, UK #12;#12;IMPROVING FUTURE CLIMATE PREDICTION USING Climate Symposium 2008 - Earth's Climate: Past, Present and Future", convened by H. Elderfield, M. Bickle

  3. Refining climate models

    ScienceCinema (OSTI)

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

    2014-06-26

    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.

  4. Refining climate models

    SciTech Connect (OSTI)

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

    2012-10-31

    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. 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

  6. Climate Models and Climate Change Guillaume Mauger

    E-Print Network [OSTI]

    Climate Models and Climate Change Guillaume Mauger gmauger@uw.edu Climate Impacts Group University of Washington Outline: · Climate Change 101 · Why do we care? · Climate models: · About, UncertainDes, Performance, and Projec

  7. 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.

    2011-11-23

    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.

  8. A Framework for Modeling Uncertainty in Regional Climate Change

    E-Print Network [OSTI]

    climate models). The modeling framework revolves around the Massachusetts Institute of Technology (MITA Framework for Modeling Uncertainty in Regional Climate Change Erwan Monier, Xiang Gao, Jeffery processes of policy development and implementation, climate change research needs to focus on improving

  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

    2004-12-01

    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. Final scientific report for DOE award title: Improving the Representation of Ice Sedimentation Rates in Global Climate Models

    SciTech Connect (OSTI)

    Mitchell, David L.

    2013-09-05

    It is well known that cirrus clouds play a major role in regulating the earth’s climate, but the details of how this works are just beginning to be understood. This project targeted the main property of cirrus clouds that influence climate processes; the ice fall speed. That is, this project improves the representation of the mass-weighted ice particle fall velocity, Vm, in climate models, used to predict future climate on global and regional scales. Prior to 2007, the dominant sizes of ice particles in cirrus clouds were poorly understood, making it virtually impossible to predict how cirrus clouds interact with sunlight and thermal radiation. Due to several studies investigating the performance of optical probes used to measure the ice particle size distribution (PSD), as well as the remote sensing results from our last ARM project, it is now well established that the anomalously high concentrations of small ice crystals often reported prior to 2007 were measurement artifacts. Advances in the design and data processing of optical probes have greatly reduced these ice artifacts that resulted from the shattering of ice particles on the probe tips and/or inlet tube, and PSD measurements from one of these improved probes (the 2-dimensional Stereo or 2D-S probe) are utilized in this project to parameterize Vm for climate models. Our original plan in the proposal was to parameterize the ice PSD (in terms of temperature and ice water content) and ice particle mass and projected area (in terms of mass- and area-dimensional power laws or m-D/A-D expressions) since these are the microphysical properties that determine Vm, and then proceed to calculate Vm from these parameterized properties. But the 2D-S probe directly measures ice particle projected area and indirectly estimates ice particle mass for each size bin. It soon became apparent that the original plan would introduce more uncertainty in the Vm calculations than simply using the 2D-S measurements to directly calculate Vm. By calculating Vm directly from the measured PSD, ice particle projected area and estimated mass, more accurate estimates of Vm are obtained. These Vm values were then parameterized for climate models by relating them to (1) sampling temperature and ice water content (IWC) and (2) the effective diameter (De) of the ice PSD. Parameterization (1) is appropriate for climate models having single-moment microphysical schemes whereas (2) is appropriate for double-moment microphysical schemes and yields more accurate Vm estimates. These parameterizations were developed for tropical cirrus clouds, Arctic cirrus, mid-latitude synoptic cirrus and mid-latitude anvil cirrus clouds based on field campaigns in these regions. An important but unexpected result of this research was the discovery of microphysical evidence indicating the mechanisms by which ice crystals are produced in cirrus clouds. This evidence, derived from PSD measurements, indicates that homogeneous freezing ice nucleation dominates in mid-latitude synoptic cirrus clouds, whereas heterogeneous ice nucleation processes dominate in mid-latitude anvil cirrus. Based on these findings, De was parameterized in terms of temperature (T) for conditions dominated by (1) homo- and (2) heterogeneous ice nucleation. From this, an experiment was designed for global climate models (GCMs). The net radiative forcing from cirrus clouds may be affected by the means ice is produced (homo- or heterogeneously), and this net forcing contributes to climate sensitivity (i.e. the change in mean global surface temperature resulting from a doubling of CO2). The objective of this GCM experiment was to determine how a change in ice nucleation mode affects the predicted global radiation balance. In the first simulation (Run 1), the

  11. A National Strategy for Advancing Climate Modeling

    SciTech Connect (OSTI)

    Dunlea, Edward; Elfring, Chris

    2012-12-04

    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.

  12. Climate Modeling: A Brief Exploration

    E-Print Network [OSTI]

    Blais, Brian

    Climate Modeling: A Brief Exploration Dr Hong Yang Dr Qin Leng Collin Gagnon April 9, 2014 Dr Brian;Exponential Model Gaussian Model #12;Oscillation Model Ecological Modelling 171 (2004) 433­450 Climate change; accepted 13 August 2003 Abstract Two questions about climate change remain open: detection and attribution

  13. Climate Modeling using High-Performance Computing

    SciTech Connect (OSTI)

    Mirin, A A

    2007-02-05

    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.

  14. Climate Modeling and Function Fitting

    E-Print Network [OSTI]

    Blais, Brian

    Climate Modeling and Function Fitting Brown Bag Research Wednesday, October 26, 11 #12;Abstract In this seminar I hope to explore an approach to climate modeling to which I was just introduced, which focusses are those who are interested in any of the topics of time-series analysis, climate modeling , spectrum

  15. Climate Sensitivity of the Community Climate System Model Version 4

    E-Print Network [OSTI]

    Bitz, Cecilia

    Climate Sensitivity of the Community Climate System Model Version 4 C. M. Bitz 1 , K.M. Shell 2 , P. Equilibrium climate sensitivity of the Community Climate System Model Version 4 (CCSM4) is 3.20 C for 1 version (CCSM3). The transient climate sensitivity of CCSM4 at 1 resolution is 1.72 C, which is about 0

  16. 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

  17. Climate Models and Their Evaluation

    E-Print Network [OSTI]

    Box, Jason E.

    8 Climate Models and Their Evaluation Coordinating Lead Authors: David A. Randall (USA), Richard A and Their Evaluation. In: Climate Change 2007: The Physical Science Basis. Contribution of Working Group I to the Fourth Assessment Report of the Intergovernmental Panel on Climate Change [Solomon, S., D. Qin, M

  18. Climate Analysis, Monitoring, and Modeling

    E-Print Network [OSTI]

    Climate Analysis, Monitoring, and Modeling Environmental Research Area PIER Environmental Research www.energy.ca.gov/research/ environmental August 2012 The Issue Climate change is a daunting challenge health. The energy sector will not be spared. The potential repercussions of climate change include

  19. Improving climate change detection through optimal seasonal averaging: the

    E-Print Network [OSTI]

    Wirosoetisno, Djoko

    Improving climate change detection through optimal seasonal averaging: the case of the North. (2015) Improving climate change detection through optimal seasonal averaging: the case of the North;Improving climate change detection through optimal seasonal averaging:1 the case of the North Atlantic jet

  20. ``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 : 1995/1996 Scientific Report February 1997 CERFACS ACTIVITY REPORT 1 #12; Contents 1 Climate Modelling) : : : : : : : : : : : : : : : : : 6 2.2 Anthropogenic climate change studies: scenario experiments (96) : : : : : : : : : 7 2

  1. ``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

  2. IDENTIFICATIONS AND APPLICATIONS OF COUPLED CLIMATE MODELS

    E-Print Network [OSTI]

    Yu, Jin-Yi

    IDENTIFICATIONS AND APPLICATIONS OF COUPLED CLIMATE MODELS Jin-Yi Yu Department of Earth System of environmental system models. 1. Introduction The Earth climate system consists of several major components of global warming, all four components of the Earth climate system are involved. Coupled climate models

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

    E-Print Network [OSTI]

    Hulme, Mike

    49 LHP: HULME RHP: HOW CLIMATE MODELS GAIN AND EXERCISE AUTHORITY 2 How Climate Models Gain and Exercise Authority Mike Hulme Introduction Numerical climate models have become central to the unfolding story of climate change. Climate models underpin the knowledge claims and risk assessments

  4. BioMove - Improvement and Parameterization of a Hybrid Model fo the ASsessment of Climate Change impacts on the Vegetation of California

    E-Print Network [OSTI]

    2015-01-01

    Under  Rapid  Climate  Change  and  Ocean  Acidification  L. Hannah, editors. Climate Change and Biodiversity. Yaleplanning under climate change. Biological Conservation 123:

  5. 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, Massachusetts Institute of Technology, Cambridge, MA 02139, USA Two different approaches are described

  6. 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...

  7. Evaluating climate models: Should we use weather or climate observations?

    SciTech Connect (OSTI)

    Oglesby, Robert J [ORNL; Erickson III, David J [ORNL

    2009-12-01

    Calling the numerical models that we use for simulations of climate change 'climate models' is a bit of a misnomer. These 'general circulation models' (GCMs, AKA global climate models) and their cousins the 'regional climate models' (RCMs) are actually physically-based weather simulators. That is, these models simulate, either globally or locally, daily weather patterns in response to some change in forcing or boundary condition. These simulated weather patterns are then aggregated into climate statistics, very much as we aggregate observations into 'real climate statistics'. Traditionally, the output of GCMs has been evaluated using climate statistics, as opposed to their ability to simulate realistic daily weather observations. At the coarse global scale this may be a reasonable approach, however, as RCM's downscale to increasingly higher resolutions, the conjunction between weather and climate becomes more problematic. We present results from a series of present-day climate simulations using the WRF ARW for domains that cover North America, much of Latin America, and South Asia. The basic domains are at a 12 km resolution, but several inner domains at 4 km have also been simulated. These include regions of complex topography in Mexico, Colombia, Peru, and Sri Lanka, as well as a region of low topography and fairly homogeneous land surface type (the U.S. Great Plains). Model evaluations are performed using standard climate analyses (e.g., reanalyses; NCDC data) but also using time series of daily station observations. Preliminary results suggest little difference in the assessment of long-term mean quantities, but the variability on seasonal and interannual timescales is better described. Furthermore, the value-added by using daily weather observations as an evaluation tool increases with the model resolution.

  8. Improved climate simulation by MIROC5:2 Mean states, variability, and climate sensitivity3

    E-Print Network [OSTI]

    Watanabe, Masahiro

    1 Improved climate simulation by MIROC5:2 Mean states, variability, and climate sensitivity3 4: Atmosphere and Ocean Research Institute* , The University of Tokyo, 2: Japan13 Marine Science and Technology of Industrial Science, The University of15 Tokyo, 6: Tokyo University of Marine Science and Technology16 17

  9. Questions of bias in climate models

    SciTech Connect (OSTI)

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

    2014-08-27

    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.

  10. Constraining uncertainties in climate models using climate change detection techniques

    E-Print Network [OSTI]

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

    Different atmosphere-ocean general circulation models produce significantly different projections of climate change in response to increases in greenhouse gases and aerosol concentrations in the atmosphere. The main reasons ...

  11. Climate change and uncertainty in ecological niche modeling

    E-Print Network [OSTI]

    Alvarez, Otto

    2011-01-01

    J. B. Grace (2010). "Climate change effects on an endemic-modelling under climate change." Progress in Physical2009). "The velocity of climate change." Nature 462(7276):

  12. Accelerated Climate Modeling for Energy | Argonne Leadership...

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

    Credit: Alan Scott and Mark Taylor, Sandia National Laboratories Accelerated Climate Modeling for Energy PI Name: Mark Taylor PI Email: mataylo@sandia.gov Institution: Sandia...

  13. Climate Sensitivity of the Community Climate System Model, Version 4

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

    Bitz, Cecilia M.; Shell, K. M.; Gent, P. R.; Bailey, D. A.; Danabasoglu, G.; Armour, K. C.; Holland, M. M.; Kiehl, J. T.

    2012-05-01

    Equilibrium climate sensitivity of the Community Climate System Model Version 4 (CCSM4) is 3.20°C for 1° horizontal resolution in each component. This is about a half degree Celsius higher than in the previous version (CCSM3). The transient climate sensitivity of CCSM4 at 1° resolution is 1.72°C, which is about 0.2°C higher than in CCSM3. These higher climate sensitivities in CCSM4 cannot be explained by the change to a preindustrial baseline climate. We use the radiative kernel technique to show that from CCSM3 to CCSM4, the global mean lapse-rate feedback declines in magnitude, and the shortwave cloud feedback increases. These twomore »warming effects are partially canceled by cooling due to slight decreases in the global mean water-vapor feedback and longwave cloud feedback from CCSM3 to CCSM4. A new formulation of the mixed-layer, slab ocean model in CCSM4 attempts to reproduce the SST and sea ice climatology from an integration with a full-depth ocean, and it is integrated with a dynamic sea ice model. These new features allow an isolation of the influence of ocean dynamical changes on the climate response when comparing integrations with the slab ocean and full-depth ocean. The transient climate response of the full-depth ocean version is 0.54 of the equilibrium climate sensitivity when estimated with the new slab ocean model version for both CCSM3 and CCSM4. We argue the ratio is the same in both versions because they have about the same zonal mean pattern of change in ocean surface heat flux, which broadly resembles the zonal mean pattern of net feedback strength.« less

  14. 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

    2013-06-01

    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.

  15. 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

    2011-10-01

    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.

  16. Using Ecosystem Experiments to Improve Vegetation Models

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

    Medlyn, Belinda; Zaehle, S; DeKauwe, Martin G.; Walker, Anthony P.; Dietze, Michael; Hanson, Paul J.; Hickler, Thomas; Jain, Atul; Luo, Yiqi; Parton, William; et al

    2015-05-21

    Ecosystem responses to rising CO2 concentrations are a major source of uncertainty in climate change projections. Data from ecosystem-scale Free-Air CO2 Enrichment (FACE) experiments provide a unique opportunity to reduce this uncertainty. The recent FACE Model–Data Synthesis project aimed to use the information gathered in two forest FACE experiments to assess and improve land ecosystem models. A new 'assumption-centred' model intercomparison approach was used, in which participating models were evaluated against experimental data based on the ways in which they represent key ecological processes. Identifying and evaluating the main assumptions caused differences among models, and the assumption-centered approach produced amore »clear roadmap for reducing model uncertainty. We explain this approach and summarize the resulting research agenda. We encourage the application of this approach in other model intercomparison projects to fundamentally improve predictive understanding of the Earth system.« less

  17. Center for Climate Systems Modeling Center for Climate Systems Modeling (C2SM)

    E-Print Network [OSTI]

    Fischlin, Andreas

    C2SM Center for Climate Systems Modeling Contact Center for Climate Systems Modeling (C2SM) Dr of the Earth's weather and climate.» Nicolas Gruber, Chair C2SM Partner institutions · ETH Zurich: Swiss Federal Institute of Technology Zurich · MeteoSwiss: Federal Office of Meteorology and Climatology · Empa

  18. AEROSOLS AND CLOUDS IN CHEMICAL TRANSPORT MODELS AND CLIMATE MODELS

    E-Print Network [OSTI]

    of Earth's climate system. Clouds are highly reflective in the solar spectrum, yet strongly absorbingAEROSOLS AND CLOUDS IN CHEMICAL TRANSPORT MODELS AND CLIMATE MODELS Ulrike Lohmann1 and Stephen E Forum: Perturbed Clouds in the Climate System, Frankfurt, Germany March 2-7, 2008 Environmental Sciences

  19. 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

  20. Climate predictions: the chaos and complexity in climate models

    E-Print Network [OSTI]

    Dragutin T. Mihailovi?; Gordan Mimi?; Ilija Arseni?

    2013-10-15

    Some issues which are relevant for the recent state in climate modeling have been considered. A detailed overview of literature related to this subject is given. The concept in modeling of climate, as a complex system, seen through Godel's Theorem and Rosen's definition of complexity and predictability is discussed. It is pointed out to occurrence of chaos in computing the environmental interface temperature from the energy balance equation given in a difference form. A coupled system of equations, often used in climate models is analyzed. It is shown that the Lyapunov exponent mostly has positive values allowing presence of chaos in this systems. The horizontal energy exchange between environmental interfaces, which is described by the dynamics of driven coupled oscillators, is analyzed. Their behavior and synchronization, when a perturbation is introduced in the system, as a function of the coupling parameters, the logistic parameter and the parameter of exchange, was studied calculating the Lyapunov exponent under simulations with the closed contour of N=100 environmental interfaces. Finally, we have explored possible differences in complexities of two global and two regional climate models using their output time series by applying the algorithm for calculating the Kolmogorov complexity.

  1. User-Oriented Modeling Tools for Advanced Hybrid and Climate...

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

    User-Oriented Modeling Tools for Advanced Hybrid and Climate-Appropriate Rooftop Air Conditioners User-Oriented Modeling Tools for Advanced Hybrid and Climate-Appropriate Rooftop...

  2. Climate change and uncertainty in ecological niche modeling

    E-Print Network [OSTI]

    Alvarez, Otto

    2011-01-01

    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

  3. Application of Improved Radiation Modeling to General Circulation Models

    SciTech Connect (OSTI)

    Michael J Iacono

    2011-04-07

    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.

  4. Improved steamflood analytical model 

    E-Print Network [OSTI]

    Chandra, Suandy

    2006-10-30

    The Jeff Jones steamflood model incorporates oil displacement by steam as described by Myhill and Stegemeier, and a three-component capture factor based on empirical correlations. The main drawback of the model however is the unsatisfactory...

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

    E-Print Network [OSTI]

    Long, Nicholas

    . Thus, climate science--which by nature involves advanced computing technology and methods--has beenCLIMATE SCIENCE 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

  6. Improving the Models, SACOG Perspectives

    E-Print Network [OSTI]

    California at Davis, University of

    forecasting, Vehicle emissions, Health outcomes, RHNA allocations. #12;What is the state of the models? · Tour-based models implemented in larger MPOs are a significant improvement. · Trip-based models still used in other of models and data in the SCS process is not sufficient. · Transportation has early costs and later benefits

  7. 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 ...

  8. Parameterization of Urban Characteristics for Global Climate Modeling

    E-Print Network [OSTI]

    Jackson, Trisha L.

    2011-10-31

    The data presented here are part of a global dataset developed specifically for use in climate models to simulate urban climates for specific regions of the globe. Article abstract: To help understand potential effects of urbanization on climates...

  9. Limitations of integrated assessment models of climate change

    E-Print Network [OSTI]

    Ackerman, Frank; DeCanio, Stephen J.; Howarth, Richard B.; Sheeran, Kristen

    2009-01-01

    cost-effective technologies into climate models that yieldcosts of climate policy depend heavily on how technology andTechnology forecasts: not so bright IAMs simulate the macroeconomic impacts of climate

  10. 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

  11. Improving snow albedo processes in WRF/SSiB regional climate model to assess impact of dust and black carbon in snow on surface energy balance and hydrology over western U.S.

    E-Print Network [OSTI]

    2015-01-01

    climate projections, in Climate Change 2007: The Physicalthe Intergovernmental Panel on Climate Change, edited by S.global downscaling: Climate change projections for a full

  12. Planning for Climate Change in South Florida: Climate Envelope Modeling for Threatened and Endangered

    E-Print Network [OSTI]

    Mazzotti, Frank

    resolution (e.g., National Climatic Data Center, Worldclim database). In addition to using data obtained fromWEC 282 Planning for Climate Change in South Florida: Climate Envelope Modeling for Threatened and tools that will allow natural resource managers to examine potential effects of climate change

  13. Environmental Physics Group Newsletter September 2013 Weather and Climate Modelling

    E-Print Network [OSTI]

    Williams, Paul

    Environmental Physics Group Newsletter September 2013 9 Weather and Climate Modelling Imperial and the Grantham Institute for Climate Change A half-day meeting on the topic of 'Should weather and climate increasingly common to represent subgrid-scale features in weather and climate models by including random noise

  14. ADAPTIVE GRIDS IN WEATHER AND CLIMATE MODELING

    E-Print Network [OSTI]

    Jablonowski, Christiane

    ADAPTIVE GRIDS IN WEATHER AND CLIMATE MODELING by Christiane Jablonowski A dissertation submitted adaptive grid library that he wrote for his Ph.D. thesis in the Electrical Engineering and Computer Science as a postdoctoral researcher. In addition, thanks to Detlev Majewski from the German Weather Service DWD

  15. 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

    2011-01-01

    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-

  16. CALIFORNIA CLIMATE POLICY MODELING (CCPM) DIALOG Greenhouse Gas Emissions Modeling

    E-Print Network [OSTI]

    California at Davis, University of

    H2 CALIFORNIA CLIMATE POLICY MODELING (CCPM) DIALOG Greenhouse Gas Emissions Modeling ­ California goals of criteria pollutant and GHG emission reduction. · Modelers need to work with policy makers more to policy-makers and stakeholders. 5 #12;Greenhouse Gas Emissions Modeling ­ California 2030 #12;

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

    E-Print Network [OSTI]

    Wehner, Michael; Oliker, Leonid; Shalf, John

    2008-01-01

    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

  18. Improved Geothermometry Through Multivariate Reaction Path Modeling...

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

    Improved Geothermometry Through Multivariate Reaction Path Modeling and Evaluation of Geomicrobiological Influences on Geochemical Temperature Indicators Improved Geothermometry...

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

    SciTech Connect (OSTI)

    DeLong, Edward; Harwood, Caroline; Reid, Ann

    2011-01-01

    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.

  20. Improving understanding of climate change dynamics using interactive simulations

    E-Print Network [OSTI]

    Martin Aguirre, Juan Francisco

    2008-01-01

    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 ...

  1. Using transport diagnostics to understand chemistry climate model ozone

    E-Print Network [OSTI]

    Wirosoetisno, Djoko

    Using transport diagnostics to understand chemistry climate model ozone simulations Article chemistry climate model ozone simulations. Journal of Geophysical Research - Atmospheres, 116 (D17). D17302 transport diagnostics to understand chemistry climate model ozone simulations S. E. Strahan,1 A. R. Douglass

  2. 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

  3. 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

  4. 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 ...

  5. 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 ...

  6. 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

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

    SciTech Connect (OSTI)

    Auffhammer, Maximilian; Hsiang, Solomon M.; Schlenker, Wolfram; Sobel, Adam H.

    2013-06-28

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

  8. 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.

    2013-02-07

    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.

  9. Climate Models: Rob Jacob | Argonne National Laboratory

    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: Alternative Fuels Data Center Homesum_a_epg0_fpd_mmcf_m.xls" ,"Available from WebQuantity ofkandz-cm11 OutreachProductswsicloudwsiclouddenDVA N C E D BGene NetworkNuclearDNP 20082 P r o j e c t D eClimate Models: Rob

  10. Development of a simple groundwater model for use in climate models and evaluation with Gravity Recovery and Climate Experiment data

    E-Print Network [OSTI]

    Yang, Zong-Liang

    Development of a simple groundwater model for use in climate models and evaluation with Gravity 7 April 2007. [1] Groundwater interacts with soil moisture through the exchanges of water between, groundwater is not explicitly represented in climate models. This paper developed a simple groundwater model

  11. Modeling the effects of fire severity and climate warming on...

    Office of Scientific and Technical Information (OSTI)

    Modeling the effects of fire severity and climate warming on active layer thickness and soil carbon storage of black spruce forests across the landscape in interior Alaska Citation...

  12. Continuous Evaluation of Fast Processes in Climate Models Using...

    Office of Scientific and Technical Information (OSTI)

    Technical Report: Continuous Evaluation of Fast Processes in Climate Models Using Arm Measurements Citation Details In-Document Search Title: Continuous Evaluation of Fast...

  13. A Scalable and Extensible Earth System Model for Climate Change...

    Office of Scientific and Technical Information (OSTI)

    Scalable and Extensible Earth System Model for Climate Change Science Gent, Peter; Lamarque, Jean-Francois; Conley, Andrew; Vertenstein, Mariana; Craig, Anthony 54 ENVIRONMENTAL...

  14. Adaptive Grids for Weather and Climate Models C. Jablonowski

    E-Print Network [OSTI]

    Stout, Quentin F.

    Adaptive Grids for Weather and Climate Models C. Jablonowski National Center for Atmospheric have been discussed in the literature. Nested-grid approaches are widely used at National Weather.: ADAPTIVE GRIDS FOR WEATHER AND CLIMATE MODELS two grids coincide. Other variable-resolution models

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

    SciTech Connect (OSTI)

    Jaroslav Solc

    2009-06-01

    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.

  16. Solving Problems with GCMs: General Circulation Models and Their Role in the Climate Modeling Hierarchy

    E-Print Network [OSTI]

    Robertson, Andrew W.

    Solving Problems with GCMs: General Circulation Models and Their Role in the Climate Modeling of a hierarchy of models for solving problems in climate dynamics. General circulation models (GCMs) occupy, capture all the phenomena, and solve all the problems. Hence the concept of a hierarchy of climate models

  17. A Spatial Analysis of Multivariate Output from Regional Climate Models

    E-Print Network [OSTI]

    Sain, Steve

    , Columbus, OH 43210, ncressie@stat.osu.edu. 1 #12;1 Introduction Many processes in the Earth system cannot, etc. Climate models attempt to represent this system, as well as to incorporate anthropogenic forcingsA Spatial Analysis of Multivariate Output from Regional Climate Models Stephan R. Sain,1 Reinhard

  18. Uncertainties and assessments of chemistry-climate models of the

    E-Print Network [OSTI]

    Wirosoetisno, Djoko

    and assessments of chemistry-climate models of the stratosphere. Atmospheric Chemistry and Physics, 3 (1). pp. 1, 1­27, 2003 www.atmos-chem-phys.org/acp/3/1/ Atmospheric Chemistry and Physics UncertaintiesUncertainties and assessments of chemistry-climate models of the stratosphere Article Published

  19. Chemistry climate model simulations of1 spring Antarctic ozone

    E-Print Network [OSTI]

    Wirosoetisno, Djoko

    Chemistry climate model simulations of1 spring Antarctic ozone Article Published Version Austin, J. (2010) Chemistry climate model simulations of spring Antarctic1 ozone. Journal of Geophysical Research ozone John Austin,1,2 H. Struthers,3 J. Scinocca,4 D. A. Plummer,5 H. Akiyoshi,6 A. J. G. Baumgaertner,7

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

    SciTech Connect (OSTI)

    Raymond S. Bradley; Henry F. Diaz

    2010-12-14

    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.

  1. Improving understanding, modelImproving understanding, model simulations, and prediction of thesimulations, and prediction of the

    E-Print Network [OSTI]

    Wood, Robert

    GMAO Clouds in Global Models Annual mean Control run Atmospheric models #12;CGCM Problems: NOAA CFS Model CFS Errors SST Prec CLD · The CFS model has significant errors in the SEP · There is a meridional) · These errors adversely affect the skill of CFS climate forecasts (ENSO). What model developments are required

  2. Stochastic Parameterization: Towards a new view of Weather and Climate Models

    E-Print Network [OSTI]

    Berner, Judith; Batte, Lauriane; De La Camara, Alvaro; Crommelin, Daan; Christensen, Hannah; Colangeli, Matteo; Dolaptchiev, Stamen; Franzke, Christian L E; Friederichs, Petra; Imkeller, Peter; Jarvinen, Heikki; Juricke, Stephan; Kitsios, Vassili; Lott, Franois; Lucarini, Valerio; Mahajan, Salil; Palmer, Timothy N; Penland, Cecile; Von Storch, Jin-Song; Sakradzija, Mirjana; Weniger, Michael; Weisheimer, Antje; Williams, Paul D; Yano, Jun-Ichi

    2015-01-01

    The last decade has seen the success of stochastic parameterizations in short-term, medium-range and seasonal ensembles: operational weather centers now routinely use stochastic parameterization schemes to better represent model inadequacy and improve the quantification of forecast uncertainty. Developed initially for numerical weather prediction, the inclusion of stochastic parameterizations not only provides more skillful estimates of uncertainty, but is also extremely promising for reducing longstanding climate biases and relevant for determining the climate response to forcings such as e.g., an increase of CO2. This article highlights recent results from different research groups which show that the stochastic representation of unresolved processes in the atmosphere, oceans, land surface and cryosphere of comprehensive weather and climate models a) gives rise to more reliable probabilistic forecasts of weather and climate and b) reduces systematic model bias. We make a case that the use of mathematically ...

  3. 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 ...

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

    SciTech Connect (OSTI)

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

    2004-05-06

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

  5. Changing the Climate Sensitivity of an Atmospheric General Circulation Model through Cloud Radiative Adjustment

    E-Print Network [OSTI]

    Sokolov, Andrei P.

    Conducting probabilistic climate projections with a particular climate model requires the ability to vary the model’s characteristics, such as its climate sensitivity. In this study, the authors implement and validate a ...

  6. A review on regional convection-permitting climate modeling: Demonstrations, prospects, and challenges

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

    Prein, Andreas; Langhans, Wolfgang; Fosser, Giorgia; Ferrone, Andrew; Ban, Nikolina; Goergen, Klaus; Keller, Michael; Tolle, Merja; Gutjahr, Oliver; Feser, Frauke; et al

    2015-05-27

    Regional climate modeling using convection permitting models (CPMs) emerges as a promising framework to provide more reliable climate information on regional to local scales compared to traditionally used large-scale models (LSMs). CPMs do not use convection parameterization schemes, known as a major source of errors and uncertainties, and have more accurate surface and orography elds. The drawback of CPMs is their high demand on computational resources. For this reason, the CPM climate simulations only appeared a decade ago. In this study we aim to provide a common basis for CPM climate simulations by giving a holistic review of the topic.more »The most important components in CPM, such as physical parameterizations and dynamical formulations are discussed, and an outlook on required future developments and computer architectures that would support the application of CPMs is given. Most importantly, this review presents the consolidated outcome of studies that addressed the added value of CPM climate simulations compared to LSMs. Most improvements are found for processes related to deep convection (e.g., precipitation during summer), for mountainous regions, and for the soil-vegetation-atmosphere interactions. The climate change signals of CPM simulations reveal increases in short and extreme rainfall events and an increased ratio of liquid precipitation at the surface (a decrease of hail) potentially leading to more frequent ash oods. Concluding, CPMs are a very promising tool for future climate research. However, coordinated modeling programs are crucially needed to assess their full potential and support their development.« less

  7. [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

  8. Improving recognition performance by modelling pronunciation variation. 

    E-Print Network [OSTI]

    Kessens, Judith M; Wester, Mirjam

    1997-01-01

    This paper describes a method for improving the performance of a continuous speech recognizer by modelling pronunciation variation. Although the improvements obtained with this method are small, they are in line with those ...

  9. 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

    2012-03-31

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

  10. 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

    2011-01-05

    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.

  11. 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

  12. Multi-Scale Coupling in Ocean and Climate Modeling

    SciTech Connect (OSTI)

    Zhengyu Liu, Leslie Smith

    2009-08-14

    We have made significant progress on several projects aimed at understanding multi-scale dynamics in geophysical flows. Large-scale flows in the atmosphere and ocean are influenced by stable density stratification and rotation. The presence of stratification and rotation has important consequences through (i) the conservation of potential vorticity q = {omega} {center_dot} {del} {rho}, where {omega} is the total vorticity and {rho} is the density, and (ii) the existence of waves that affect the redistribution of energy from a given disturbance to the flow. Our research is centered on quantifying the effects of potential vorticity conservation and of wave interactions for the coupling of disparate time and space scales in the oceans and the atmosphere. Ultimately we expect the work to help improve predictive capabilities of atmosphere, ocean and climate modelers. The main findings of our research projects are described.

  13. Investment Dimension: Enhanced Data Equals Better Climate Models

    SciTech Connect (OSTI)

    Roeder, Lynne R.

    2010-11-01

    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.

  14. Water Body Temperature Model for Assessing Climate Change Impacts

    E-Print Network [OSTI]

    climatological data and thermal pollution from river-based power plants to historical river flow data in orderWater Body Temperature Model for Assessing Climate Change Impacts on Thermal Cooling Ken Strzepek Climate Change Impacts on Thermal Cooling Ken Strzepek* , Charles Fant* , Yohannes Gebretsadik , Megan

  15. The effects of small perturbations in climate models 

    E-Print Network [OSTI]

    Bell, Robert Eugene

    1991-01-01

    solar constant to evaluate the response to small perturbations. The sensitivity of a noise forced energy balance climate model is compared to the GCM. Natural fluctuations are discussed and compared to the sensitivity to external forcing... on state-of-the-art supercomputers. One alternative approach employs the energy balance models (EBMs) which are sim- plified climate models that use the concept of an ensemble from classical statistical mechanics. This seems to eff'ectively decouple...

  16. 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 ...

  17. 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 ...

  18. LETTER Climate envelope modelling reveals intraspecific relationships among flowering phenology, niche breadth and potential

    E-Print Network [OSTI]

    Purugganan, Michael D.

    LETTER Climate envelope modelling reveals intraspecific relationships among flowering phenology structured can help to understand species' ecological tolerances and range limits. We modelled the climate climatic vari- ables. We found that genotypes with contrasting alleles at individual flowering time loci

  19. 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. ...

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

    SciTech Connect (OSTI)

    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

    2014-10-01

    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.

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

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

    Stan, Cristiana; Xu, Li

    2014-10-01

    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

  2. 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

    2008-03-20

    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.

  3. 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

  4. Modeling and Improving an Industrial Software Process

    E-Print Network [OSTI]

    Picco, Gian Pietro

    possible levels of maturity for a software process. At the first level, software production activities continuous improvement. It is the basis of the Japanese approach to industrial production and is applied1 Modeling and Improving an Industrial Software Process Sergio Bandinelli, Alfonso Fuggetta, Member

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

    SciTech Connect (OSTI)

    Wehner, Michael; Oliker, Leonid; Shalf, John

    2007-01-01

    We present a speculative extrapolation of the performance aspects of an atmospheric general circulation model to ultra-high resolution and describe alternative technological paths to realize integration of such a model in the relatively near future. Due to a superlinear scaling of the computational burden dictated by stability criterion, the solution of the equations of motion dominate the calculation at ultra-high resolutions. From this extrapolation, it is estimated that a credible kilometer scale atmospheric model would require at least a sustained ten petaflop computer to provide scientifically useful climate simulations. Our design study portends an alternate strategy for practical power-efficient implementations of petaflop scale systems. Embedded processor technology could be exploited to tailor a custom machine designed to ultra-high climate model specifications at relatively affordable cost and power considerations. The major conceptual changes required by a kilometer scale climate model are certain to be difficult to implement. Although the hardware, software, and algorithms are all equally critical in conducting ultra-high climate resolution studies, it is likely that the necessary petaflop computing technology will be available in advance of a credible kilometer scale climate model.

  6. 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

  7. 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.

    2012-10-01

    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.

  8. 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

  9. STOCHASTIC MODELING OF HURRICANE DAMAGE UNDER CLIMATE CHANGE

    E-Print Network [OSTI]

    Katz, Richard

    STOCHASTIC MODELING OF HURRICANE DAMAGE UNDER CLIMATE CHANGE Rick Katz Institute for Study from Hurricanes (2) Stochastic Model for Damage (3) Effects of El Nińo (4) Trends in Extreme Hurricanes (5) Unresolved Issues #12;(1) Economic Damage from Hurricanes · Data -- Pielke and Landsea (1998) Web

  10. 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.

  11. Climate Models: Rob Jacob | Argonne National Laboratory

    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: Alternative Fuels Data Center Homesum_a_epg0_fpd_mmcf_m.xls" ,"Available from WebQuantity ofkandz-cm11 Outreach Home Room News PublicationsAudits &BradburyMayARM-0501Classroom-presentations SignClimate

  12. 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: Alternative Fuels Data Center Homesum_a_epg0_fpd_mmcf_m.xls" ,"Available from WebQuantity of NaturalDukeWakefieldSulfateSciTechtail.Theory ofDid youOxygen GenerationTechnologies |EducationChemical Sciences HomeClimate

  13. 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

    2008-09-30

    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.

  14. 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

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

    SciTech Connect (OSTI)

    Winterhalter, Wade

    2011-09-01

    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. Agent Model Development for Assessing Climate-Induced Geopolitical Instability.

    SciTech Connect (OSTI)

    Boslough, Mark B.; Backus, George A.

    2005-12-01

    We present the initial stages of development of new agent-based computational methods to generate and test hypotheses about linkages between environmental change and international instability. This report summarizes the first year's effort of an originally proposed three-year Laboratory Directed Research and Development (LDRD) project. The preliminary work focused on a set of simple agent-based models and benefited from lessons learned in previous related projects and case studies of human response to climate change and environmental scarcity. Our approach was to define a qualitative model using extremely simple cellular agent models akin to Lovelock's Daisyworld and Schelling's segregation model. Such models do not require significant computing resources, and users can modify behavior rules to gain insights. One of the difficulties in agent-based modeling is finding the right balance between model simplicity and real-world representation. Our approach was to keep agent behaviors as simple as possible during the development stage (described herein) and to ground them with a realistic geospatial Earth system model in subsequent years. This work is directed toward incorporating projected climate data--including various C02 scenarios from the Intergovernmental Panel on Climate Change (IPCC) Third Assessment Report--and ultimately toward coupling a useful agent-based model to a general circulation model.3

  17. Microbial dormancy improves development and experimental validation of ecosystem model

    SciTech Connect (OSTI)

    Wang, Gangsheng; Jagadamma, Sindhu; Mayes, Melanie; Schadt, Christopher Warren; Steinweg, Jessica M; Gu, Lianhong; Post, Wilfred M

    2015-01-01

    Climate feedbacks from soils can result from environmental change followed by response of plant and microbial communities, and/or associated changes in nutrient cycling. Explicit consideration of microbial life history traits and functions may be necessary to predict climate feedbacks due to changes in the physiology and community composition of microbes and their associated effect on carbon cycling. Here, we enhanced the Microbial-Enzyme-mediated Decomposition (MEND) model by incorporating microbial dormancy and the ability to track multiple isotopes of carbon. We tested two versions of MEND, i.e., MEND with dormancy and MEND without dormancy, against long-term (270 d) lab incubations of four soils with isotopically-labeled substrates. MEND without dormancy adequately fitted multiple observations (total and 14C respiration, and dissolved organic carbon), but at the cost of significantly underestimating the total microbial biomass. The MEND with dormancy improved estimates of microbial biomass by 20 71% over the MEND without dormancy. We observed large differences for two fitted model parameters, the specific maintenance and growth rates for active microbes, depending on whether dormancy was considered. Together our model extrapolations of the incubation study show that long-term soil incubations with observations in multiple carbon pools are necessary to estimate both decomposition and microbial parameters. These efforts should provide essential support to future field- and global-scale simulations and enable more confident predictions of feedbacks between environmental change and carbon cycling.

  18. The Atmospheric Chemistry and Climate Model Intercomparison Project (ACCMIP): Overview and Description of Models, Simulations and Climate Diagnostics

    SciTech Connect (OSTI)

    Lamarque, J.-F.; Shindell, Drew; Josse, B.; Young, P. J.; Cionni, I.; Eyring, Veronika; Bergmann, D.; Cameron-Smith, Philip; Collins, W. J.; Doherty, R.; Dalsoren, S.; Faluvegi, G.; Folberth, G.; Ghan, Steven J.; Horowitz, L.; Lee, Y. H.; MacKenzie, I. A.; Nagashima, T.; Naik, Vaishali; Plummer, David; Righi, M.; Rumbold, S.; Schulz, M.; Skeie, R. B.; Stevenson, D. S.; Strode, S.; Sudo, K.; Szopa, S.; Voulgarakis, A.; Zeng, G.

    2013-02-07

    The Atmospheric Chemistry and Climate Model Intercomparison Project (ACCMIP) consists of a series of timeslice experiments targeting the long-term changes in atmospheric composition between 1850 and 2100, with the goal of documenting radiative forcing and the associated composition changes. Here we introduce the various simulations performed under ACCMIP and the associated model output. The ACCMIP models have a wide range of horizontal and vertical resolutions, vertical extent, chemistry schemes and interaction with radiation and clouds. While anthropogenic and biomass burning emissions were specified for all time slices in the ACCMIP protocol, it is found that the natural emissions lead to a significant range in emissions, mostly for ozone precursors. The analysis of selected present-day climate diagnostics (precipitation, temperature, specific humidity and zonal wind) reveals biases consistent with state-of-the-art climate models. The model-to-model comparison of changes in temperature, specific humidity and zonal wind between 1850 and 2000 and between 2000 and 2100 indicates mostly consistent results, but with outliers different enough to possibly affect their representation of climate impact on chemistry.

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

    SciTech Connect (OSTI)

    Kocarev, Ljupco

    2014-07-02

    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. Thermal physiology and species distribution models reveal climate

    E-Print Network [OSTI]

    Combes, Stacey A.

    ORIGINAL ARTICLE Thermal physiology and species distribution models reveal climate vulnerability warming than tropical species based on their larger thermal safety margins, the distance between ambient temperatures and species' thermal optima. We sought to test the prediction that high latitude amphibians

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

    E-Print Network [OSTI]

    ACCEPTABILITY by Nic Rivers B.Eng, M.R.M. THESIS SUBMITTED IN PARTIAL FULFILLMENT OF THE REQUIREMENTS FOR THE DEGREE OF DOCTOR OF PHILOSOPHY IN THE SCHOOL OF RESOURCE AND ENVIRONMENTAL MANAGEMENT c Nic Rivers 2011 appropriately. #12;APPROVAL Name: Nic Rivers Degree: Doctor of Philosophy Title of Thesis: Modeling climate

  2. 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...

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

    Office of Environmental Management (EM)

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

  4. 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. ...

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

    E-Print Network [OSTI]

    Maret, Susan

    2011-01-01

    Review: A Vast Machine: Computer Models, Climate Data, andEdwards, Paul N. A Vast Machine: Computer Models, ClimateEdwards, Paul N. 2004. "A vast machine: standards as social

  6. 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

  7. Climate induced changes in benthic macrofauna--A non-linear model approach Karin Junker a,

    E-Print Network [OSTI]

    Dippner, Joachim W.

    Climate induced changes in benthic macrofauna--A non-linear model approach Karin Junker a, , Dusan macrofauna communities Climate indices Neural network Climate variability Time series forecasting Regime-nearest neighbours" (OPKNN) are applied to relate various climate indices to time series of biomass, abun- dance

  8. 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

  9. 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

    2012-12-01

    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.

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

    SciTech Connect (OSTI)

    Russell, Lynn M

    2013-06-18

    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.

  11. 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

    2015-01-01

    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.

  12. U.S. Senate Committee on Commerce, Science and Transportation Hearing on "A Time for Change: Improving the Federal Climate Change

    E-Print Network [OSTI]

    Boynton, Walter R.

    : Improving the Federal Climate Change Research and Information Program" November 14, 2007 Testimony of Dr to appear before you today to address improving the Federal climate change research and information program engaged in several assessments of the environmental consequences of climate change. Notably, I served

  13. Ecological Modelling 114 (1999) 113135 A model of surface fire, climate and forest pattern in the Sierra

    E-Print Network [OSTI]

    Wallin, David O.

    1999-01-01

    Ecological Modelling 114 (1999) 113­135 A model of surface fire, climate and forest pattern it integrates climate, fire and forest pattern. The model simulates a forest stand as a grid of 15×15 m forest with the local site water balance and forest condition, thus linking climate with the fire regime. Fires occur

  14. ARM - Evaluation Product - Climate Modeling Best Estimate (CMBE)

    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: Alternative Fuels Data Center Homesum_a_epg0_fpd_mmcf_m.xls" ,"Available from WebQuantity ofkandz-cm11 Outreach HomeA Better Anode Design to Improve4AJ01) (See EnergyCurrent :DatastreamstomsAprilProductsClimate

  15. Reproducibility by Climate Models of Cloud Radiative Forcing Associated with Tropical Convection

    E-Print Network [OSTI]

    Masunaga, Hirohiko

    for monthly mean data from twentieth-century simulations of 18 climate models participating in phase 3 perturbation is thus fundamental for our understanding of climate change, but shows no consistency in eitherReproducibility by Climate Models of Cloud Radiative Forcing Associated with Tropical Convection

  16. Precipitation Characteristics in Eighteen Coupled Climate Models National Center for Atmospheric Research,* Boulder, Colorado

    E-Print Network [OSTI]

    Dai, Aiguo

    Precipitation Characteristics in Eighteen Coupled Climate Models AIGUO DAI National Center) ABSTRACT Monthly and 3-hourly precipitation data from twentieth-century climate simulations by the newest-related variability, convective versus stratiform precipitation ratio, precipitation frequency and intensity

  17. Climate implications of carbonaceous aerosols: An aerosol microphysical study using the GISS/MATRIX climate model

    SciTech Connect (OSTI)

    Bauer, Susanne E.; Menon, Surabi; Koch, Dorothy; Bond, Tami; Tsigaridis, Kostas

    2010-04-09

    Recently, attention has been drawn towards black carbon aerosols as a likely short-term climate warming mitigation candidate. However the global and regional impacts of the direct, cloud-indirect and semi-direct forcing effects are highly uncertain, due to the complex nature of aerosol evolution and its climate interactions. Black carbon is directly released as particle into the atmosphere, but then interacts with other gases and particles through condensation and coagulation processes leading to further aerosol growth, aging and internal mixing. A detailed aerosol microphysical scheme, MATRIX, embedded within the global GISS modelE includes the above processes that determine the lifecycle and climate impact of aerosols. This study presents a quantitative assessment of the impact of microphysical processes involving black carbon, such as emission size distributions and optical properties on aerosol cloud activation and radiative forcing. Our best estimate for net direct and indirect aerosol radiative forcing change is -0.56 W/m{sup 2} between 1750 and 2000. However, the direct and indirect aerosol effects are very sensitive to the black and organic carbon size distribution and consequential mixing state. The net radiative forcing change can vary between -0.32 to -0.75 W/m{sup 2} depending on these carbonaceous particle properties. Assuming that sulfates, nitrates and secondary organics form a coating shell around a black carbon core, rather than forming a uniformly mixed particles, changes the overall net radiative forcing from a negative to a positive number. Black carbon mitigation scenarios showed generally a benefit when mainly black carbon sources such as diesel emissions are reduced, reducing organic and black carbon sources such as bio-fuels, does not lead to reduced warming.

  18. 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

  19. 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)

  20. Limitations of integrated assessment models of climate change

    E-Print Network [OSTI]

    Ackerman, Frank; DeCanio, Stephen J.; Howarth, Richard B.; Sheeran, Kristen

    2009-01-01

    Climatic Change (2009) 95:297–315 DOI 10.1007/s10584-009-MD 20686-3001, USA Climatic Change (2009) 95:297–315 ofgreenhouse gas (GHG) Climatic Change (2009) 95:297– 315

  1. Sandia Energy - Arctic Climate Measurements

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

    Arctic Climate Measurements Home Climate & Earth Systems Climate Measurement & Modeling Arctic Climate Measurements Arctic Climate Measurementscwdd2015-05-08T01:51:20+00:00 A...

  2. Computational load in model physics of the parallel NCAR community climate model

    SciTech Connect (OSTI)

    Michalakes, J.G.; Nanjundiah, R.S.

    1994-11-01

    Maintaining a balance of computational load over processors is a crucial issue in parallel computing. For efficient parallel implementation, complex codes such as climate models need to be analyzed for load imbalances. In the present study we focus on the load imbalances in the physics portion of the community climate model`s (CCM2) distributed-memory parallel implementation on the Intel Touchstone DELTA computer. We note that the major source of load imbalance is the diurnal variation in the computation of solar radiation. Convective weather patterns also cause some load imbalance. Land-ocean contrast is seen to have little effect on computational load in the present version of the model.

  3. Holism and Entrenchment in Climate Model Validation J. Lenhard and E. Winsberg, draft March 7, 2008

    E-Print Network [OSTI]

    Winsberg, Eric B.

    of complex systems, particularly modelers of the earth's climate, face a deeply entrenched form models--with a particular emphasis on models of the earth's climate. The first claim is about holism. We, on the one hand, and the dynamics of the real world system to be modeled, on the other. To be sure

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

    E-Print Network [OSTI]

    DĂ­az, JesĂşs 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

  5. IPA: improved phone modelling with recurrent neural networks 

    E-Print Network [OSTI]

    Robinson, Tony; Hochberg, Mike; Renals, Steve

    This paper describes phone modelling improvements to the hybrid connectionist-hidden Markov model speech recognition system developed at Cambridge University. These improvements are applied to phone recognition from the ...

  6. 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.

    2004-07-30

    for approaches Can. J. Zool. 82: 851–858 (2004) doi: 10.1139/Z04-064 © 2004 NRC Canada 851 Received 22 July 2003. Accepted 21 May 2004. Published on the NRC Research Press Web site at http://cjz.nrc.ca on 30 July 2004. A.T. Peterson. 1 Natural History Museum...-Cordero, V., Soberon, J., Bartley, J., Buddemeier, R.H., and Navarro-Siguenza, A.G. 2001. Effects of global climate change on geographic distributions of Mexican Cracidae. Ecol. Model. 144: 21–30. Peterson, A.T., Ball, L.G., and Cohoon, K.C. 2002a. Predicting...

  7. ARM - PI Product - Climate Modeling Best Estimate (CMBE)

    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: Alternative Fuels Data Center Homesum_a_epg0_fpd_mmcf_m.xls" ,"Available from WebQuantity ofkandz-cm11 Outreach HomeA Better Anode DesigngovCampaignsSpring SinglegovFieldgovDataPI Data ProductsClimate Modeling Best

  8. Terrestrial aridity and its response to greenhouse warming1 across CMIP5 climate models2

    E-Print Network [OSTI]

    Frierson, Dargan

    Terrestrial aridity and its response to greenhouse warming1 across CMIP5 climate models2 Jacob climatic aridity, it makes sense to consider P relative to potential37 evapotranspiration PET (e using v4.3.2 of the AMS LATEX template 1 #12;ABSTRACT 2 #12;The aridity of a terrestrial climate

  9. Technical Note: On the use of nudging for aerosol-climate model intercomparison studies

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

    Zhang, K.; Wan, H.; Liu, X.; Ghan, S. J.; Kooperman, G. J.; Ma, P.-L.; Rasch, P. J.

    2014-04-24

    Nudging is an assimilation technique widely used in the development and evaluation of climate models. Constraining 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 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 sensitivity of simulated ice formation to anthropogenic aerosolmore »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 nudging the horizontal winds but not temperature is a good strategy for the investigation of aerosol indirect effects through ice clouds, since it provides well-constrained meteorology without strongly perturbing the model's mean climate.« less

  10. Atmospheric Properties from the 2006 Niamey Deployment and Climate Simulation with a Geodesic Grid Coupled Climate Model

    SciTech Connect (OSTI)

    Jensen, M; Johnson, K; Mather, J; Randall, D

    2008-03-01

    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.

  11. 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...

  12. A CONCEPT TO ASSESS THE PERFORMANCE OF A PERMAFROST MODEL RUN FULLY COUPLED WITH A CLIMATE MODEL

    E-Print Network [OSTI]

    Moelders, Nicole

    A CONCEPT TO ASSESS THE PERFORMANCE OF A PERMAFROST MODEL RUN FULLY COUPLED WITH A CLIMATE MODEL APPROVED: Dean, College of Natural Science and Mathematics Dean of the Graduate School Date #12;A CONCEPT TO ASSESS THE PERFORMANCE OF A PERMAFROST MODEL RUN FULLY COUPLED WITH A CLIMATE MODEL A DISSERTATION

  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.

    2014-05-16

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

    E-Print Network [OSTI]

    Edwards, Paul N.

    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 this: Global warming is a myth. It's all model predictions, nothing but simulations. Before you believe

  15. Technical Note: On the use of nudging for aerosol–climate model intercomparison studies

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

    Zhang, K.; Wan, H.; Liu, X.; Ghan, S. J.; Kooperman, G. J.; Ma, P.-L.; Rasch, P. J.; Neubauer, D.; Lohmann, U.

    2014-08-26

    Nudging as an assimilation technique has seen increased use in recent years in the development and evaluation of climate models. Constraining 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 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 (CAM5), due to the systematic temperature bias in the standard model and the sensitivity ofmore »simulated ice formation to anthropogenic aerosol concentration, nudging towards reanalysis results in substantial reductions in the ice cloud amount and the impact of anthropogenic aerosols on long-wave 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. Results from both CAM5 and a second aerosol–climate model ECHAM6-HAM2 also indicate that compared to the wind-and-temperature nudging, constraining only winds leads to better agreement with the free-running model in terms of the estimated shortwave cloud forcing and the simulated convective activities. This suggests nudging the horizontal winds but not temperature is a good strategy for the investigation of aerosol indirect effects since it provides well-constrained meteorology without strongly perturbing the model's mean climate.« less

  16. Improving complex enterprises with system models

    E-Print Network [OSTI]

    Hemann, Justin M. (Justin Matthew)

    2005-01-01

    Air Force sustainment operations are the focus of an intensive internal effort to improve performance and reduce costs. Past improvement initiatives have often failed to produce the intended results, and have caused ...

  17. 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

    2013-11-01

    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.

  18. Shan Sun Rainer Bleck Multi-century simulations with the coupled GISSHYCOM climate model

    E-Print Network [OSTI]

    Shan Sun Ć Rainer Bleck Multi-century simulations with the coupled GISS­HYCOM climate model models. Diversity in model design is one of the very few S. Sun (&) NASA Goddard Institute for Space

  19. A Sparse Bayesian Model for Dependence Analysis of Extremes: Climate Applications

    E-Print Network [OSTI]

    Obradovic, Zoran

    , 360 Huntington Avenue, Boston, MA, USA Zoran Obradovic zoran@ist.temple.edu Center for Data Analysis relevant for improved understanding of hydrological extremes un- der climate variability and change and urgency across societal priorities, ranging from natural haz- ards and climate change to security

  20. 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

  1. 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

  2. California Wintertime Precipitation in Regional and Global Climate Models

    SciTech Connect (OSTI)

    Caldwell, P M

    2009-04-27

    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.

  3. Short-term time step convergence in a climate model

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

    Wan, Hui; Rasch, Philip J.; Taylor, Mark; Jablonowski, Christiane

    2015-02-11

    A testing procedure is designed to assess the convergence property of a global climate model with respect to time step size, based on evaluation of the root-mean-square temperature difference at the end of very short (1 h) simulations with time step sizes ranging from 1 s to 1800 s. A set of validation tests conducted without sub-grid scale parameterizations confirmed that the method was able to correctly assess the convergence rate of the dynamical core under various configurations. The testing procedure was then applied to the full model, and revealed a slow convergence of order 0.4 in contrast to themore »expected first-order convergence. Sensitivity experiments showed without ambiguity that the time stepping errors in the model were dominated by those from the stratiform cloud parameterizations, in particular the cloud microphysics. This provides a clear guidance for future work on the design of more accurate numerical methods for time stepping and process coupling in the model.« less

  4. Short-term Time Step Convergence in a Climate Model

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

    Wan, Hui; Rasch, Philip J.; Taylor, Mark; Jablonowski, Christiane

    2015-02-11

    A testing procedure is designed to assess the convergence property of a global climate model with respect to time step size, based on evaluation of the root-mean-square temperature difference at the end of very short (1 h) simulations with time step sizes ranging from 1 s to 1800 s. A set of validation tests conducted without sub-grid scale parameterizations confirmed that the method was able to correctly assess the convergence rate of the dynamical core under various configurations. The testing procedure was then applied to the full model, and revealed a slow convergence of order 0.4 in contrast to themore »expected first-order convergence. Sensitivity experiments showed without ambiguity that the time stepping errors in the model were dominated by those from the stratiform cloud parameterizations, in particular the cloud microphysics. This provides a clear guidance for future work on the design of more accurate numerical methods for time stepping and process coupling in the model.« less

  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

    2013-07-15

    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. 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

    2013-08-09

    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.

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

    E-Print Network [OSTI]

    Edwards, Paul N.

    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

  8. Sand dune dynamics and climate change: A modeling H. Yizhaq,1

    E-Print Network [OSTI]

    Ashkenazy, Yossi "Yosef"

    Sand dune dynamics and climate change: A modeling approach H. Yizhaq,1 Y. Ashkenazy,1 and H. Tsoar2] We provide several examples for the coexistence of active and fixed sand dunes under similar climatic conditions, namely, with respect to wind power and precipitation rate. A model is developed for dune

  9. LoadBalancing Algorithms for Climate Models Ian T. Foster and Brian R. Toonen

    E-Print Network [OSTI]

    Load­Balancing Algorithms for Climate Models Ian T. Foster and Brian R. Toonen Mathematics­balancing algorithms that we have devel­ oped for PCCM2, a scalable parallel implementation of the Community Climate Model, and present exper­ imental results that demonstrate the effectiveness of these algorithms

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

    E-Print Network [OSTI]

    Robock, Alan

    Nuclear winter revisited with a modern climate model and current nuclear arsenals: Still of climate model simulations of the response to smoke and dust from a massive nuclear exchange between the superpowers could be summarized as ``nuclear winter,'' with rapid temperature, precipitation, and insolation

  11. Multi-century Changes to Global Climate and Carbon Cycle: Results from a Coupled Climate and Carbon Cycle Model

    SciTech Connect (OSTI)

    Bala, G; Caldeira, K; Mirin, A; Wickett, M; Delire, C

    2005-02-17

    In this paper, we use a coupled climate and carbon cycle model to investigate the global climate and carbon cycle changes out to year 2300 that would occur if CO{sub 2} emissions from all the currently estimated fossil fuel resources were released to the atmosphere. By year 2300, the global climate warms by about 8 K and atmospheric CO{sub 2} reaches 1423 ppmv. The warming is higher than anticipated because the sensitivity to radiative forcing increases as the simulation progresses. In our simulation, the rate of emissions peak at over 30 PgC yr{sup -1} early in the 22nd century. Even at year 2300, nearly 50% of cumulative emissions remain in the atmosphere. In our simulations both soils and living biomass are net carbon sinks throughout the simulation. Despite having relatively low climate sensitivity and strong carbon uptake by the land biosphere, our model projections suggest severe long-term consequences for global climate if all the fossil-fuel carbon is ultimately released to the atmosphere.

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

    SciTech Connect (OSTI)

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

    2012-05-02

    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.

  13. The use of imprecise processing to improve accuracy in weather and climate prediction

    SciTech Connect (OSTI)

    Düben, Peter D.; McNamara, Hugh; Palmer, T.N.

    2014-08-15

    The use of stochastic processing hardware and low precision arithmetic in atmospheric models is investigated. Stochastic processors allow hardware-induced faults in calculations, sacrificing bit-reproducibility and precision in exchange for improvements in performance and potentially accuracy of forecasts, due to a reduction in power consumption that could allow higher resolution. A similar trade-off is achieved using low precision arithmetic, with improvements in computation and communication speed and savings in storage and memory requirements. As high-performance computing becomes more massively parallel and power intensive, these two approaches may be important stepping stones in the pursuit of global cloud-resolving atmospheric modelling. The impact of both hardware induced faults and low precision arithmetic is tested using the Lorenz '96 model and the dynamical core of a global atmosphere model. In the Lorenz '96 model there is a natural scale separation; the spectral discretisation used in the dynamical core also allows large and small scale dynamics to be treated separately within the code. Such scale separation allows the impact of lower-accuracy arithmetic to be restricted to components close to the truncation scales and hence close to the necessarily inexact parametrised representations of unresolved processes. By contrast, the larger scales are calculated using high precision deterministic arithmetic. Hardware faults from stochastic processors are emulated using a bit-flip model with different fault rates. Our simulations show that both approaches to inexact calculations do not substantially affect the large scale behaviour, provided they are restricted to act only on smaller scales. By contrast, results from the Lorenz '96 simulations are superior when small scales are calculated on an emulated stochastic processor than when those small scales are parametrised. This suggests that inexact calculations at the small scale could reduce computation and power costs without adversely affecting the quality of the simulations. This would allow higher resolution models to be run at the same computational cost.

  14. Improved computer models support genetics research

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

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

  15. 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...

  16. 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.

    2014-03-27

    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.

  17. 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

    2014-12-15

    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.

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

    SciTech Connect (OSTI)

    JH Mather; DA Randall; CJ Flynn

    2008-06-30

    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. This report describes the aerosol optical depth (AOD) product.

  19. "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

  20. 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.

    2012-05-10

    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.

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

    SciTech Connect (OSTI)

    Drake, John B; Worley, Patrick H; Hoffman, Forrest M; Jones, Phil

    2009-01-01

    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.

  2. 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.

    2014-08-26

    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.

  3. Simulation Models for Improved Water Heating Systems

    E-Print Network [OSTI]

    Lutz, Jim

    2014-01-01

    Air Conditioners. Arthur D. Little, Cambridge, Mass. No.Model User’s Guide. Arthur D. Little, Cambridge, Mass. DE-described in the Arthur D. Little model will serve as the

  4. Simple improvements to classical bubble nucleation models

    E-Print Network [OSTI]

    Tanaka, Kyoko K; Angélil, Raymond; Diemand, Jürg

    2015-01-01

    We revisit classical nucleation theory (CNT) for the homogeneous bubble nucleation rate and improve the classical formula using a new prefactor in the nucleation rate. Most of the previous theoretical studies have used the constant prefactor determined by the bubble growth due to the evaporation process from the bubble surface. However, the growth of bubbles is also regulated by the thermal conduction, the viscosity, and the inertia of liquid motion. These effects can decrease the prefactor significantly, especially when the liquid pressure is much smaller than the equilibrium one. The deviation in the nucleation rate between the improved formula and the CNT can be as large as several orders of magnitude. Our improved, accurate prefactor and recent advances in molecular dynamics simulations and laboratory experiments for argon bubble nucleation enable us to precisely constrain the free energy barrier for bubble nucleation. Assuming the correction to the CNT free energy is of the functional form suggested by T...

  5. A Study of Longwave Radiation Codes for Climate Studies: Validation with ARM Observations and Tests in General Circulation Models

    SciTech Connect (OSTI)

    Robert G. Ellingson

    2004-09-28

    One specific goal of the Atmospheric Radiation Measurements (ARM) program is to improve the treatment of radiative transfer in General Circulation Models (GCMs) under clear-sky, general overcast and broken cloud conditions. Our project was geared to contribute to this goal by attacking major problems associated with one of the dominant radiation components of the problem --longwave radiation. The primary long-term project objectives were to: (1) develop an optimum longwave radiation model for use in GCMs that has been calibrated with state-of-the-art observations for clear and cloudy conditions, and (2) determine how the longwave radiative forcing with an improved algorithm contributes relatively in a GCM when compared to shortwave radiative forcing, sensible heating, thermal advection and convection. The approach has been to build upon existing models in an iterative, predictive fashion. We focused on comparing calculations from a set of models with operationally observed data for clear, overcast and broken cloud conditions. The differences found through the comparisons and physical insights have been used to develop new models, most of which have been tested with new data. Our initial GCM studies used existing GCMs to study the climate model-radiation sensitivity problem. Although this portion of our initial plans was curtailed midway through the project, we anticipate that the eventual outcome of this approach will provide both a better longwave radiative forcing algorithm and from our better understanding of how longwave radiative forcing influences the model equilibrium climate, how improvements in climate prediction using this algorithm can be achieved.

  6. Valuing climate impacts in integrated assessment models: the MIT IGSM*

    E-Print Network [OSTI]

    interactions among natural and human climate system components; objectively assess uncertainty in economic, monitor and verify greenhouse gas emissions and climatic impacts. This reprint is one of a series intended to their daily lives--crop yield, food prices, premature death, flooding or drought events, land use change

  7. Improving the Performance of Air-Conditioning Systems in an ASEAN Climate 

    E-Print Network [OSTI]

    Busch, J. F.; Warren, M. L.

    1988-01-01

    This paper describes an analysis of air conditioning performance under hot and humid tropical climate conditions appropriate to the Association of South East Asian Nations (ASEAN) countries. This region, with over 280 million people, has one...

  8. 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

  9. 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

    2009-01-01

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

  10. Simulation Models for Improved Water Heating Systems

    E-Print Network [OSTI]

    Lutz, Jim

    2014-01-01

    with studies of solar water heaters. Another area withto model hybrid water heaters or solar thermal systems. Theof a Gas Tankless Water Heater. ” In SOLAR 2008 San Diego,

  11. Simulation Models for Improved Water Heating Systems

    E-Print Network [OSTI]

    Lutz, Jim

    2014-01-01

    E. Inc. 1990. “Residential Water Heating Study: TechnicalScott. 2007. “HWSIM Hot Water Distribution Model Validationand Simulation of a Smart Water Heater. ” In Workshop in

  12. Detecting changes in seasonal precipitation extremes using regional climate model projections: Implications for managing fluvial flood

    E-Print Network [OSTI]

    Fowler, Hayley

    further demonstrates that existing precautionary allowances for climate change used for flood managementClick Here for Full Article Detecting changes in seasonal precipitation extremes using regional climate model projections: Implications for managing fluvial flood risk H. J. Fowler1 and R. L. Wilby2

  13. Accounting for species taxonomy improves distribution models Aidin Niamir a

    E-Print Network [OSTI]

    models, multispecies models, species distribution models Abstract: The use of species atlas data of species distribution models. Using atlas data, two taxonomically enhanced datasets were created for 356. Enhancement of atlas data by excluding irrelevant absences based on species taxonomy significantly improved

  14. Improved Crosstalk Modeling with Applications to Noise Constrained Interconnect Optimization

    E-Print Network [OSTI]

    Pan, David Z.

    Improved Crosstalk Modeling with Applications to Noise Constrained Interconnect Optimization This paper presents a highly accurate yet efficient crosstalk noise model, the 2-˘ model, and applies to be noise immune, ac- curate yet efficient noise models are needed to guide interconnect optimizations

  15. HIDDENARTICULATOR MARKOV MODELS: PERFORMANCE IMPROVEMENTS AND ROBUSTNESS TO NOISE

    E-Print Network [OSTI]

    Noble, William Stafford

    HIDDEN­ARTICULATOR MARKOV MODELS: PERFORMANCE IMPROVEMENTS AND ROBUSTNESS TO NOISE Matt Richardson@cs}.washington.edu ABSTRACT A Hidden­Articulator Markov Model (HAMM) is a Hidden Markov Model (HMM) in which each state], we extended the articulatory­feature model introduced by Erler [7] by using diphone units and a new

  16. 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

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

    E-Print Network [OSTI]

    Cho, S.; Haberl, J.

    2009-01-01

    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... HIGH-PERFORMANCE OFFICE BUILDING SIMULATION MODEL FOR A HOT AND HUMID CLIMATE Soolyeon Cho1 and Jeff S. Haberl2 1The Catholic University of America, Washington, D.C., USA 2Texas A&M University, College Station, TX, USA ABSTRACT...

  18. Simple improvements to classical bubble nucleation models

    E-Print Network [OSTI]

    Kyoko K. Tanaka; Hidekazu Tanaka; Raymond Angélil; Jürg Diemand

    2015-07-13

    We revisit classical nucleation theory (CNT) for the homogeneous bubble nucleation rate and improve the classical formula using a new prefactor in the nucleation rate. Most of the previous theoretical studies have used the constant prefactor determined by the bubble growth due to the evaporation process from the bubble surface. However, the growth of bubbles is also regulated by the thermal conduction, the viscosity, and the inertia of liquid motion. These effects can decrease the prefactor significantly, especially when the liquid pressure is much smaller than the equilibrium one. The deviation in the nucleation rate between the improved formula and the CNT can be as large as several orders of magnitude. Our improved, accurate prefactor and recent advances in molecular dynamics simulations and laboratory experiments for argon bubble nucleation enable us to precisely constrain the free energy barrier for bubble nucleation. Assuming the correction to the CNT free energy is of the functional form suggested by Tolman, the precise evaluations of the free energy barriers suggest the Tolman length is $\\simeq 0.3 \\sigma$ independently of the temperature for argon bubble nucleation, where $\\sigma$ is the unit length of the Lenard-Jones potential. With this Tolman correction and our new prefactor one gets accurate bubble nucleation rate predictions in the parameter range probed by current experiments and molecular dynamics simulations.

  19. 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

    2013-04-08

    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.

  20. 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 ...

  1. Climate Change and Extinctions

    E-Print Network [OSTI]

    Sinervo, Barry

    2013-01-01

    Lectures presents: Climate Change and Extinctions Happening2013. He will present a climate change extinction model that

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

    SciTech Connect (OSTI)

    Lackmann, Gary

    2013-06-10

    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.

  3. Zooming in: From global to regional climate models | Argonne...

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

    to explore climate changes that occur on a diurnal scale, such as thunderstorms or urban heat islands. With Mira, approximately 1 million core-hours are needed to run a one-year...

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

    E-Print Network [OSTI]

    Reilly, John

    2012-05-22

    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 ...

  5. Interactive chemistry and climate models in global change studies

    E-Print Network [OSTI]

    Wang, Chien.; Prinn, Ronald G.

    Continually increasing atmospheric concentrations of radiatively important chemical species such as CO2, CH4, N2O, tropospheric O3, and certain halocarbons most likely will cause future climate changes, which could in turn ...

  6. World's largest climate research site pilots integrated modeling...

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

    at the Southern Great Plains site. Image courtesy of the U.S. Department of Energy ARM Climate Research Facility; click to view larger. A graphic illustrating new data collection...

  7. 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 ...

  8. A new Geoengineering Model Intercomparison Project (GeoMIP) experiment designed for climate and chemistry models

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

    Tilmes, S.; Mills, Mike; Niemeier, Ulrike; Schmidt, Hauke; Robock, Alan; Kravitz, Benjamin S.; Lamarque, J. F.; Pitari, G.; English, J. M.

    2015-01-15

    A new Geoengineering Model Intercomparison Project (GeoMIP) experiment "G4 specified stratospheric aerosols" (short name: G4SSA) is proposed to investigate the impact of stratospheric aerosol geoengineering on atmosphere, chemistry, dynamics, climate, and the environment. In contrast to the earlier G4 GeoMIP experiment, which requires an emission of sulfur dioxide (SO?) into the model, a prescribed aerosol forcing file is provided to the community, to be consistently applied to future model experiments between 2020 and 2100. This stratospheric aerosol distribution, with a total burden of about 2 Tg S has been derived using the ECHAM5-HAM microphysical model, based on a continuous annualmore »tropical emission of 8 Tg SO? yr?ą. A ramp-up of geoengineering in 2020 and a ramp-down in 2070 over a period of 2 years are included in the distribution, while a background aerosol burden should be used for the last 3 decades of the experiment. The performance of this experiment using climate and chemistry models in a multi-model comparison framework will allow us to better understand the impact of geoengineering and its abrupt termination after 50 years in a changing environment. The zonal and monthly mean stratospheric aerosol input data set is available at https://www2.acd.ucar.edu/gcm/geomip-g4-specified-stratospheric-aerosol-data-set.« less

  9. A new Geoengineering Model Intercomparison Project (GeoMIP) experiment designed for climate and chemistry models

    SciTech Connect (OSTI)

    Tilmes, S. [National Center for Atmospheric Research, Boulder, CO (United States); Mills, Mike [National Center for Atmospheric Research, Boulder, CO (United States); Niemeier, Ulrike [Max Planck Inst. for Meteorology, Hamburg (Germany); Schmidt, Hauke [Max Planck Inst. for Meteorology, Hamburg (Germany); Robock, Alan [Rutgers Univ., New Brunswick, NJ (United States). Dept. of Environmental Sciences; Kravitz, Benjamin S. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Lamarque, J. F. [National Center for Atmospheric Research, Boulder, CO (United States); Pitari, G. [Univ. L'Aquila (Italy). Dept. of Physical and Chemical Sciences; English, J. M. [Univ. of Colorado, Boulder, CO (United States)

    2015-01-01

    A new Geoengineering Model Intercomparison Project (GeoMIP) experiment "G4 specified stratospheric aerosols" (short name: G4SSA) is proposed to investigate the impact of stratospheric aerosol geoengineering on atmosphere, chemistry, dynamics, climate, and the environment. In contrast to the earlier G4 GeoMIP experiment, which requires an emission of sulfur dioxide (SO?) into the model, a prescribed aerosol forcing file is provided to the community, to be consistently applied to future model experiments between 2020 and 2100. This stratospheric aerosol distribution, with a total burden of about 2 Tg S has been derived using the ECHAM5-HAM microphysical model, based on a continuous annual tropical emission of 8 Tg SO? yr?ą. A ramp-up of geoengineering in 2020 and a ramp-down in 2070 over a period of 2 years are included in the distribution, while a background aerosol burden should be used for the last 3 decades of the experiment. The performance of this experiment using climate and chemistry models in a multi-model comparison framework will allow us to better understand the impact of geoengineering and its abrupt termination after 50 years in a changing environment. The zonal and monthly mean stratospheric aerosol input data set is available at https://www2.acd.ucar.edu/gcm/geomip-g4-specified-stratospheric-aerosol-data-set.

  10. 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

    2012-11-01

    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.

  11. Modelling vegetation dynamics at global scale due to climate changes: Comparison of two approaches

    SciTech Connect (OSTI)

    Belotelov, N.V.; Bogatyrev, B.G.; Lobanov, A.I.

    1996-12-31

    Climate changes will influence vegetation dynamics. One of the ways of forecasting these changes is the creation of mathematical models describing vegetation dynamics. Computer experiments can then be conducted under climate change scenarios. Two main approaches are used to create such models. The first approach is based on a bioclimatic dynamic approach. The second approach is based on modelling the main eco-physiological processes. The bioclimatic dynamic approach consists of hypotheses about vegetation types or biomes, and their interrelationships with climate. In the eco-physiological approach, a detailed description of the processes, such as production, mortality, plants migration and their competition is presented. A number of computer experiments has been conducted for several climatic scenario for Russia and the whole world. A qualitative comparison of the results with the results of an earlier bioclimatic model has been done.

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

    E-Print Network [OSTI]

    Winter, Jonathan (Jonathan Mark)

    2010-01-01

    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 ...

  13. Evaluating the Use of Ocean Models of Different Complexity in Climate Change Studies

    E-Print Network [OSTI]

    Sokolov, Andrei P.

    The study of the uncertainties in future climate projections requires large ensembles of simulations with different values of model characteristics that define its response to external forcing. These characteristic include ...

  14. The Surface-Pressure Signature of Atmospheric Tides in Modern Climate Models

    E-Print Network [OSTI]

    Covey, Curt

    Although atmospheric tides driven by solar heating are readily detectable at the earth’s surface as variations in air pressure, their simulations in current coupled global climate models have not been fully examined. This ...

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

    E-Print Network [OSTI]

    Rivington, Michael

    2011-06-28

    This Thesis explored a range of approaches to study the uncertainty and impacts associated with climate change at the farm scale in Scotland. The research objective was to use a process of uncertainty evaluation and simulation modelling to provide...

  16. Coupling of Integrated Biosphere Simulator to Regional Climate Model Version 3

    E-Print Network [OSTI]

    Winter, Jonathan (Jonathan Mark)

    A description of the coupling of Integrated Biosphere Simulator (IBIS) to Regional Climate Model version 3 (RegCM3) is presented. IBIS introduces several key advantages to RegCM3, most notably vegetation dynamics, the ...

  17. 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

  18. An Urban Parameterization for a Global Climate Model. Part I: Formulation and Evaluation for Two Cities

    E-Print Network [OSTI]

    Oleson, Keith W.; Bonan, Gordon B.; Feddema, Johannes J.; Vertenstein, M.; Grimmond, C.S.B.

    2008-01-01

    stream_size 70935 stream_content_type text/plain stream_name Feddema_Urban_Parameterization_Climate Model_PtI.pdf.txt stream_source_info Feddema_Urban_Parameterization_Climate Model_PtI.pdf.txt Content-Encoding UTF-8 Content-Type..., all of these studies have focused on land use/land cover re- lated to changes in vegetation types. Urbanization, or the expansion of built-up areas, is an important yet less studied aspect of anthropogenic land use/land cover change in climate science...

  19. Link between land-ocean warming contrast and surface relative humidities in simulations with coupled climate models

    E-Print Network [OSTI]

    Byrne, Michael Patrick

    Simulations of warming climates with coupled climate models exhibit strong land-ocean contrasts in changes in surface temperature and relative humidity, but little land-ocean contrast in changes in equivalent potential ...

  20. An Improved MUSIC Model for Gibbsite Surfaces

    SciTech Connect (OSTI)

    Mitchell, Scott C.; Bickmore, Barry R.; Tadanier, Christopher J.; Rosso, Kevin M.

    2004-06-01

    Here we use gibbsite as a model system with which to test a recently published, bond-valence method for predicting intrinsic pKa values for surface functional groups on oxides. At issue is whether the method is adequate when valence parameters for the functional groups are derived from ab initio structure optimization of surfaces terminated by vacuum. If not, ab initio molecular dynamics (AIMD) simulations of solvated surfaces (which are much more computationally expensive) will have to be used. To do this, we had to evaluate extant gibbsite potentiometric titration data that where some estimate of edge and basal surface area was available. Applying BET and recently developed atomic force microscopy methods, we found that most of these data sets were flawed, in that their surface area estimates were probably wrong. Similarly, there may have been problems with many of the titration procedures. However, one data set was adequate on both counts, and we applied our method of surface pKa int prediction to fitting a MUSIC model to this data with considerable success—several features of the titration data were predicted well. However, the model fit was certainly not perfect, and we experienced some difficulties optimizing highly charged, vacuum-terminated surfaces. Therefore, we conclude that we probably need to do AIMD simulations of solvated surfaces to adequately predict intrinsic pKa values for surface functional groups.

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

    SciTech Connect (OSTI)

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

    2014-05-01

    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.

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

    E-Print Network [OSTI]

    Thompson, Starley Lee

    1977-01-01

    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. 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 are emerging that leads to cost reductions in construction. In this strive towards improvement, logistics on cost savings from the logistics perspective in different areas of the logistic system. Keywords

  4. 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

    2012-06-01

    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 presented as powerful tools that distill complex datasets into concise statements on likely impact, and as highly effective communication devices. Capsule: "Combining dynamical modeling of high-impact weather using traditional regional climate models with statistical techniques allows for comprehensive sampling of the full distribution, uncertainty estimation, direct assessment of impacts, and increased confidence in future changes."

  5. Software Maintainability Improvement: Integrating Standards and Models William C. Chu,

    E-Print Network [OSTI]

    Chung, Yeh-Ching

    Software Maintainability Improvement: Integrating Standards and Models William C. Chu, Dpt Science and Engineering, Southeast University, China National Key Laboratory of Software Engineering, Wuhan University, China Abstract Software standards are highly recommended because they promise faster

  6. Improved lumped parameter thermal modelling of synchronous generators 

    E-Print Network [OSTI]

    Mejuto, Carlos

    2010-01-01

    Within the existing available mix of numerical and analytical thermal analysis options, lumped parameter thermal modelling is selected as the operational backbone to develop an improved novel synchronous generator thermal ...

  7. Some improvements to the spherical collapse model

    E-Print Network [OSTI]

    Antonino Del Popolo

    2008-01-07

    I study the joint effect of dynamical friction, tidal torques and cosmological constant on clusters of galaxies formation I show that within high-density environments, such as rich clusters of galaxies, both dynamical friction and tidal torques slows down the collapse of low-? peaks producing an observable variation in the time of collapse of the perturbation and, as a consequence, a reduction in the mass bound to the collapsed perturbation Moreover, the delay of the collapse produces a tendency for less dense regions to accrete less mass, with respect to a classical spherical model, inducing a biasing of over-dense regions toward higher mass I show how the threshold of collapse is modified if dynamical friction, tidal torques and a non-zero cosmological constant are taken into account and I use the Extended Press Schecter (EPS) approach to calculate the effects on the mass function Then, I compare the numerical mass function given in Reed et al (2003) with the theoretical mass function obtained in the present paper I show that the barrier obtained in the present paper gives rise to a better description of the mass function evolution with respect to other previous models (Sheth & Tormen 1999, MNRAS, 308, 119 (hereafter ST); Sheth & Tormen 2002, MNRAS, 329, 61 (hereafter ST1))

  8. Atmospheric Properties from the 2006 Niamey Deployment and Climate Simulation with a Geodesic Grid Coupled Climate Model - First Quarter 2008

    SciTech Connect (OSTI)

    JH Mather; D Randall

    2007-12-30

    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 is ‘initial formulation of the algorithm to produce and make available, new continuous time series of retrieved cloud , aerosol and dust properties, based on results from the ARM Mobile Facility deployment in Niger, Africa. The first quarter milestone has been achieved.

  9. 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.

    2012-12-01

    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

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

    SciTech Connect (OSTI)

    Penner, Joyce

    2012-06-30

    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.

  11. 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

  12. Improving Energy Efficiency by Developing Components for Distributed Cooling and Heating Based on Thermal Comfort Modeling

    Office of Energy Efficiency and Renewable Energy (EERE)

    Discusses comfort model enhancement/validation, climate system efficiency parameters and system trade off, and powertrain mode operation changes to further vehicle energy saving while preserving occupant comfort.

  13. 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

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

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

    Nazarenko, L.; NASA Goddard Institute for Space Studies, New York, NY; Schmidt, G. A.; Miller, R. L.; Tausnev, N.; Trinnovim LLC, New York, NY; Kelley, M.; Trinnovim LLC, New York, NY; Ruedy, R.; Trinnovim LLC, New York, NY; et al

    2015-02-24

    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

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

    SciTech Connect (OSTI)

    Nazarenko, L.; Schmidt, G. A.; Miller, R. L.; Tausnev, N.; Kelley, M.; Ruedy, R.; Russell, G. L.; Aleinov, I.; Bauer, M.; Bauer, S.; Bleck, R.; Canuto, V.; Cheng, Y.; Clune, T. L.; Del Genio, A. D.; Faluvegi, G.; Hansen, J. E.; Healy, R. J.; Kiang, N. Y.; Koch, D.; Lacis, A. A.; LeGrande, A. N.; Lerner, J.; Lo, K. K.; Menon, S.; Oinas, V.; Perlwitz, J.; Puma, M. J.; Rind, D.; Romanou, A.; Sato, M.; Shindell, D. T.; Sun, S.; Tsigaridis, K.; Unger, N.; Voulgarakis, A.; Yao, M. -S.; Zhang, Jinlun

    2015-02-24

    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 atmospheric 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.

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

    SciTech Connect (OSTI)

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

    2014-01-01

    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.

  17. 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

    2014-01-01

    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.

  18. Improved Power Modeling of DDR SDRAMs Karthik Chandrasekar

    E-Print Network [OSTI]

    Improved Power Modeling of DDR SDRAMs Karthik Chandrasekar Computer Engineering TU Delft one of the most defining aspects in designing modern embedded systems. In this context, DDR SDRAM model on power and energy for DDR3-800. We show differences of up to 60% in energy

  19. 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, the fuels are often toxic to cell growth, creating a negative feedback loop that limits biofuel production

  20. GFDL's ESM2 Global Coupled ClimateCarbon Earth System Models. Part I: Physical Formulation and Baseline Simulation Characteristics

    E-Print Network [OSTI]

    Wittenberg, Andrew

    GFDL's ESM2 Global Coupled Climate­Carbon Earth System Models. Part I: Physical Formulation coupled carbon­climate Earth System Models, ESM2M and ESM2G, are described. These models demonstrate al. 2002; Delworth et al. 2006). Our approach has been to de- velop two Earth System Models

  1. 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

    2013-06-30

    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.

  2. Modeling Building Energy Use and HVAC Efficiency Improvements in Extreme Hot and Humid Regions 

    E-Print Network [OSTI]

    Bible, Mitchell

    2011-10-21

    improvement was studied. Simulations were run in the relatively milder climates of Houston and Phoenix and compared to those found for Doha. It was found that variable speed fan operation is a more cost effective option for milder climates, while outside air...

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

    SciTech Connect (OSTI)

    Rood, Richard B; Jablonowski, Christiane

    2012-10-31

    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.

  4. 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

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

    E-Print Network [OSTI]

    Laitner, J. A.

    2007-01-01

    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...

  6. 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

  7. Characteristics of tropical cyclones in high-resolution models in the present climate

    SciTech Connect (OSTI)

    Shaevitz, Daniel A.; Camargo, Suzana J.; Sobel, Adam H.; Jonas, Jeffrey A.; Kim, Daehyun; Kumar, Arun; Lim, Young -Kwon; Reed, Kevin A.; Roberts, Malcolm J.; Scoccimarro, Enrico; Vidale, Pier Luigi; Wang, Hui; Zhao, Ming; Henderson, Naomi

    2014-12-05

    The global characteristics of tropical cyclones (TCs) simulated by several climate models are analyzed and compared with observations. The global climate models were forced by the same sea surface temperature (SST) fields in two types of experiments, using climatological SST and interannually varying SST. TC tracks and intensities are derived from each model's output fields by the group who ran that model, using their own preferred tracking scheme; the study considers the combination of model and tracking scheme as a single modeling system, and compares the properties derived from the different systems. Overall, the observed geographic distribution of global TC frequency was reasonably well reproduced. As expected, with the exception of one model, intensities of the simulated TC were lower than in observations, to a degree that varies considerably across models.

  8. Characteristics of tropical cyclones in high-resolution models in the present climate

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

    Shaevitz, Daniel A.; Camargo, Suzana J.; Sobel, Adam H.; Jonas, Jeffrey A.; Kim, Daehyun; Kumar, Arun; LaRow, Timothy E.; Lim, Young -Kwon; Murakami, Hiroyuki; Reed, Kevin A.; et al

    2014-12-05

    The global characteristics of tropical cyclones (TCs) simulated by several climate models are analyzed and compared with observations. The global climate models were forced by the same sea surface temperature (SST) fields in two types of experiments, using climatological SST and interannually varying SST. TC tracks and intensities are derived from each model's output fields by the group who ran that model, using their own preferred tracking scheme; the study considers the combination of model and tracking scheme as a single modeling system, and compares the properties derived from the different systems. Overall, the observed geographic distribution of global TCmore »frequency was reasonably well reproduced. As expected, with the exception of one model, intensities of the simulated TC were lower than in observations, to a degree that varies considerably across models.« less

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

    E-Print Network [OSTI]

    Dommenget, Dietmar

    on the surface energy balance by very simple repre- sentations of solar and thermal radiation, the atmosphericConceptual understanding of climate change with a globally resolved energy balance model Dietmar will introduce a very simple, globally resolved energy bal- ance (GREB) model, which is capable of simulating

  10. 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

  11. Dansgaard-Oeschger oscillations predicted in a comprehensive model of glacial climate

    E-Print Network [OSTI]

    Peltier, W. Richard

    " salt oscillator in the Atlantic W. Richard Peltier1 and Guido Vettoretti1 1 Department of Physics formation [e.g., Sakai and Peltier, 1996, 1997] subsequent to which the overturning circulation "fibrillates and Peltier [2013] who employed the Community Climate System Model version 3 (CCSM3) model to perform an Last

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

    E-Print Network [OSTI]

    Winter, Jonathan (Jonathan Mark)

    2006-01-01

    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, ...

  13. Modeling the response of subglacial drainage at Paakitsoq, West Greenland, to 21st century climate change

    E-Print Network [OSTI]

    Mayaud, Jerome R.; Banwell, Alison F.; Arnold, Neil S.; Willis, Ian C.

    2015-01-22

    , and into the future. Here, we apply a physically-based, subglacial hydrological model to the Paakitsoq region, west Greenland, and run it into the future to calculate patterns of daily subglacial water pressure fluctuations in response to climatic warming. The model...

  14. 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

  15. Centennial-scale interactions between the carbon cycle and anthropogenic climate change using a dynamic Earth system model

    E-Print Network [OSTI]

    Winguth, Arne

    a dynamic Earth system model A. Winguth Center for Climatic Research, Department of Atmospheric and Oceanic; accepted 26 October 2005; published 15 December 2005. [1] A complex Earth system model including atmosphere and anthropogenic climate change using a dynamic Earth system model, Geophys. Res. Lett., 32, L23714, doi:10

  16. 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

    2013-10-19

    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.

  17. DOE Project Taps HPC for Next-Generation Climate 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: Alternative Fuels Data Center Homesum_a_epg0_fpd_mmcf_m.xls" ,"Available from WebQuantity ofkandz-cm11 Outreach Home Room NewsInformation Current HAB Packet HanfordDOE Project Taps HPC for Next-Generation Climate

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

    E-Print Network [OSTI]

    Koven, C.D.

    2014-01-01

    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)

  19. 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

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

    E-Print Network [OSTI]

    Maryland at College Park, University of

    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

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

    E-Print Network [OSTI]

    Theodore E. Liolios

    2003-06-23

    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.

  2. Open problem: Dynamic Relational Models for Improved Hazardous Weather Prediction

    E-Print Network [OSTI]

    McGovern, Amy

    Open problem: Dynamic Relational Models for Improved Hazardous Weather Prediction Amy McGovern1 dis- covery methods for use on mesoscale weather data. Severe weather phenomena such as tornados, thun, current techniques for predicting severe weather are tied to specific characteristics of the radar systems

  3. A Hierarchical Evaluation of Regional Climate Simulations

    SciTech Connect (OSTI)

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

    2013-08-20

    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.

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

    E-Print Network [OSTI]

    -driven, the Program uses extensive Earth system and economic data and models to produce quantitative analysis of the Program's work lies MIT's Integrated Global System Model. Through this integrated model, the Program seeks interactions. We demonstrate a new modeling system that integrates cli- matic and hydrological determinants

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

    SciTech Connect (OSTI)

    Johannesson, G

    2010-03-17

    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.

  6. 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

    2008-09-30

    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.

  7. Global warming and climate change - predictive models for temperate and tropical regions

    SciTech Connect (OSTI)

    Malini, B.H.

    1997-12-31

    Based on the assumption of 4{degree}C increase of global temperature by the turn of 21st century due to the accumulation of greenhouse gases an attempt is made to study the possible variations in different climatic regimes. The predictive climatic water balance model for Hokkaido island of Japan (a temperate zone) indicates the possible occurrence of water deficit for two to three months, which is a unknown phenomenon in this region at present. Similarly, India which represents tropical region also will experience much drier climates with increased water deficit conditions. As a consequence, the thermal region of Hokkaido which at present is mostly Tundra and Micro thermal will change into a Meso thermal category. Similarly, the moisture regime which at present supports per humid (A2, A3 and A4) and Humid (B4) climates can support A1, B4, B3, B2 and B1 climates indicating a shift towards drier side of the climatic spectrum. Further, the predictive modes of both the regions have indicated increased evapotranspiration rates. Although there is not much of change in the overall thermal characteristics of the Indian region the moisture regime indicates a clear shift towards the aridity in the country.

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

    SciTech Connect (OSTI)

    Estep, Donald

    2013-04-15

    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.

  9. 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 ...

  10. Visualizing Life Zone Boundary Sensitivities Across Climate Models and Temporal Spans

    SciTech Connect (OSTI)

    Sisneros, Roberto R; Huang, Jian; Ostrouchov, George; Hoffman, Forrest M

    2011-01-01

    Life zones are a convenient and quantifiable method for delineating areas with similar plant and animal communities based on bioclimatic conditions. Such ecoregionalization techniques have proved useful for defining habitats and for studying how these habitats may shift due to environmental change. The ecological impacts of climate change are of particular interest. Here we show that visualizations of the geographic projection of life zones may be applied to the investigation of potential ecological impacts of climate change using the results of global climate model simulations. Using a multi-factor classification scheme, we show how life zones change over time based on quantitative model results into the next century. Using two straightforward metrics, we identify regions of high sensitivity to climate changes from two global climate simulations under two different greenhouse gas emissions scenarios. Finally, we identify how preferred human habitats may shift under these scenarios. We apply visualization methods developed for the purpose of displaying multivariate relationships within data, especially for situations that involve a large number of concurrent relationships. Our method is based on the concept of multivariate classification, and is implemented directly in VisIt, a production quality visualization package.

  11. Circumpolar Deep Water Circulation and Variability in a Coupled Climate Model AGUS SANTOSO AND MATTHEW H. ENGLAND

    E-Print Network [OSTI]

    Santoso, Agus

    Circumpolar Deep Water Circulation and Variability in a Coupled Climate Model AGUS SANTOSO Deep Water (CDW) is analyzed using a long-term integration of a coupled climate model. The variability into the Southern Ocean via North Atlantic Deep Water (NADW). Salinity dipole anomalies appear to propagate around

  12. 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

  13. Improved Specifications for FEMA Procured Ruggedized Manufactured Homes for Hot/Humid Climates 

    E-Print Network [OSTI]

    Thomas-Rees, S.; Barkaszi, S.; Chandra, S.; Chasar, D.; McIlvaine, J.

    2006-01-01

    stream_source_info ESL-HH-06-07-25.pdf.txt stream_content_type text/plain stream_size 32416 Content-Encoding UTF-8 stream_name ESL-HH-06-07-25.pdf.txt Content-Type text/plain; charset=UTF-8 Improved Specifications... requesting quotes from manufact home builders to build the homes in accordance with HUD Manufacturing Housing Standards, al as Title 24 (Chasar, et al. 2004). The ma homes specified to these standards, devel 70’s, are often constructed to the minimu...

  14. Climate Change and National Security

    E-Print Network [OSTI]

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

    2015-01-01

    data needed to construct effective climate change models and forecasts. Academic “Centers of Excellence” that focus on climate change

  15. An Evaluation of Unsaturated Flow Models in an Arid Climate

    SciTech Connect (OSTI)

    Dixon, J.

    1999-12-01

    The objective of this study was to evaluate the effectiveness of two unsaturated flow models in arid regions. The area selected for the study was the Area 5 Radioactive Waste Management Site (RWMS) at the Nevada Test Site in Nye County, Nevada. The two models selected for this evaluation were HYDRUS-1D [Simunek et al., 1998] and the SHAW model [Flerchinger and Saxton, 1989]. Approximately 5 years of soil-water and atmospheric data collected from an instrumented weighing lysimeter site near the RWMS were used for building the models with actual initial and boundary conditions representative of the site. Physical processes affecting the site and model performance were explored. Model performance was based on a detailed sensitivity analysis and ultimately on storage comparisons. During the process of developing descriptive model input, procedures for converting hydraulic parameters for each model were explored. In addition, the compilation of atmospheric data collected at the site became a useful tool for developing predictive functions for future studies. The final model results were used to evaluate the capacities of the HYDRUS and SHAW models for predicting soil-moisture movement and variable surface phenomena for bare soil conditions in the arid vadose zone. The development of calibrated models along with the atmospheric and soil data collected at the site provide useful information for predicting future site performance at the RWMS.

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

    E-Print Network [OSTI]

    Kuhlbrodt, Till

    is the 12 improvement of convection parameterization schemes, but the question of grid geometry also plays.elsevier.com/locate/omodol OCEMOD 100 No. of Pages 18, DTD = 4.3.1 28 August 2003 Type ARTICLE IN PRESS #12;UNCORRECTED PROOF 26 1 density gradient actually vanishes, one observes a strong vertical turbulent mixing to 32 depths of 2 km

  17. 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 Markus reconstructions for the last glacial inception. As postulated in35 Milankovitch's hypothesis the only necessary positive feedback is the snow albedo36 feedback, which is initiated by reduced melting of snow and sea

  18. Freshwater Discharge, Sediment Transport, and Modeled Climate Impacts of the Final Drainage of Glacial Lake Agassiz

    E-Print Network [OSTI]

    Bush, John W.M.

    Freshwater Discharge, Sediment Transport, and Modeled Climate Impacts of the Final Drainage, whereas the postflood outflow through Hudson Strait had a lower load of suspended sediment and was buoyant hemispheric extent. This claim was bolstered by analyses of marine sediments in the tropical and North

  19. Optimizing Computations in Weather and Climate Prediction Models* F. BAER, BANGLIN ZHANG, AND BING ZHANG

    E-Print Network [OSTI]

    Baer, Ferdinand

    Optimizing Computations in Weather and Climate Prediction Models* F. BAER, BANGLIN ZHANG, AND BING scenarios for many time scales, more computer power than is currently available will be needed. One and sometimes with a biosphere included, are very complex and require so much computing power on available

  20. Climate-based models of spatial patterns of species richness in Egypt's butterfly

    E-Print Network [OSTI]

    Obbard, Darren

    ORIGINAL ARTICLE Climate-based models of spatial patterns of species richness in Egypt's butterfly, Egyptian Environmental Affairs Agency, Maadi, Cairo and 3 Suez Canal University, Ismailia, Egypt of butterfly and mammal species richness. Location Egypt. Methods Data on the occurrence of butterflies

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

    SciTech Connect (OSTI)

    Burtis, M.D.; Razuvaev, V.N.; Sivachok, S.G.

    1996-10-01

    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.

  2. Sensitivity of modeled Cretaceous climate to insolation forcing created by varying Earth-Sun orbital relationships

    SciTech Connect (OSTI)

    Glancy, T.J. Jr.

    1992-01-01

    Rhythmic sedimentation patterns observed within the Cretaceous Western Interior Seaway, such as those in the Bridge Creek Limestone Member of the Greenhorn Limestone Formation exposed near Pueblo, Colorado, appear to be a response to episodic climate change. These climatic variations could, in turn, be forced by the periodic insolation change over the North American continent created by Milankovitch-scale Earth-Sun orbital relationships - eccentricity (100 kiloyears), obliquity (41 kiloyears) and precession of the equinox (23 kiloyears). To test the sensitivity of Cretaceous climate to changes in Milankovitch-scale insolation forcing, a set of seasonal simulations using maximum difference insolation forcing conditions was conducted with the National Center for Atmospheric Research's Community Climate Model using 100 MA Cretaceous paleogeography and paleotopography. Analysis showed statistically significant differences in surface temperature, precipitation, surface wind, storm track location, and upwelling occurred over many regions of the Cretaceous Earth, particularly in the summer and winter monsoon system. During Northern Hemisphere winter, differences in the position of storm passage over Cretaceous western North America under maximum difference insolation forcing conditions varies the precipitation received over the southern Western Interior Seaway at the location where the Bridge Creek Limestone Member rhythmic sedimentation was produced. Northern Hemisphere winter simulations removing all sea ice from the model showed little difference in the climatic effects observed over southwestern North America from the case with sea ice present. Additional simulations varying only the obliquity within the model suggest that the observed Bridge Creek Limestone Member rhythmic sedimentation patterns are controlled by climatic change produced by cyclic variation in the precession of the equinox and eccentricity insolation forcing.

  3. 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

  4. 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 ...

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

    SciTech Connect (OSTI)

    Bond-Lamberty, Benjamin

    2013-11-08

    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.

  6. 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 ...

  7. 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

  8. Simulating the Biogeochemical and Biogeophysical Impacts of Transient Land Cover Change and Wood Harvest in the Community Climate System Model (CCSM4) from 1850 to 2100

    E-Print Network [OSTI]

    Lawrence, Peter J.; Feddema, Johannes J.; Bonan, Gordon B.; Meehl, Gerald A.; O’ Neill, Brian C.; Oleson, Keith W.; Levis, Samuel; Lawrence, David M.; Kluzek, Erik; Lindsay, Keith

    2012-05-01

    To assess the climate impacts of historical and projected land cover change in the Community Climate System Model, version 4 (CCSM4), new time series of transient Community Land Model, version 4 (CLM4) plant functional ...

  9. 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.

    2004-07-01

    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.

  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

    2007-01-01

    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. Short ensembles: An Efficient Method for Discerning Climate-relevant Sensitivities in Atmospheric General Circulation Models

    SciTech Connect (OSTI)

    Wan, Hui; Rasch, Philip J.; Zhang, Kai; Qian, Yun; Yan, Huiping; Zhao, Chun

    2014-09-08

    This paper explores the feasibility of an experimentation strategy for investigating sensitivities in fast components of atmospheric general circulation models. The basic idea is to replace the traditional serial-in-time long-term climate integrations by representative ensembles of shorter simulations. The key advantage of the proposed method lies in its efficiency: since fewer days of simulation are needed, the computational cost is less, and because individual realizations are independent and can be integrated simultaneously, the new dimension of parallelism can dramatically reduce the turnaround time in benchmark tests, sensitivities studies, and model tuning exercises. The strategy is not appropriate for exploring sensitivity of all model features, but it is very effective in many situations. Two examples are presented using the Community Atmosphere Model version 5. The first example demonstrates that the method is capable of characterizing the model cloud and precipitation sensitivity to time step length. A nudging technique is also applied to an additional set of simulations to help understand the contribution of physics-dynamics interaction to the detected time step sensitivity. In the second example, multiple empirical parameters related to cloud microphysics and aerosol lifecycle are perturbed simultaneously in order to explore which parameters have the largest impact on the simulated global mean top-of-atmosphere radiation balance. Results show that in both examples, short ensembles are able to correctly reproduce the main signals of model sensitivities revealed by traditional long-term climate simulations for fast processes in the climate system. The efficiency of the ensemble method makes it particularly useful for the development of high-resolution, costly and complex climate models.

  13. Short-term time step convergence in a climate model

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

    Wan, Hui; Rasch, Philip J.; Taylor, Mark A.; Jablonowski, Christiane

    2015-02-11

    This paper evaluates the numerical convergence of very short (1 h) simulations carried out with a spectral-element (SE) configuration of the Community Atmosphere Model version 5 (CAM5). While the horizontal grid spacing is fixed at approximately 110 km, the process-coupling time step is varied between 1800 and 1 s to reveal the convergence rate with respect to the temporal resolution. Special attention is paid to the behavior of the parameterized subgrid-scale physics. First, a dynamical core test with reduced dynamics time steps is presented. The results demonstrate that the experimental setup is able to correctly assess the convergence rate ofmore »the discrete solutions to the adiabatic equations of atmospheric motion. Second, results from full-physics CAM5 simulations with reduced physics and dynamics time steps are discussed. It is shown that the convergence rate is 0.4—considerably slower than the expected rate of 1.0. Sensitivity experiments indicate that, among the various subgrid-scale physical parameterizations, the stratiform cloud schemes are associated with the largest time-stepping errors, and are the primary cause of slow time step convergence. While the details of our findings are model specific, the general test procedure is applicable to any atmospheric general circulation model. The need for more accurate numerical treatments of physical parameterizations, especially the representation of stratiform clouds, is likely common in many models. The suggested test technique can help quantify the time-stepping errors and identify the related model sensitivities.« less

  14. Toward understanding predictability of climate: a linear stochastic modeling approach 

    E-Print Network [OSTI]

    Wang, Faming

    2004-11-15

    in examining a dynamical system. The origin and growth of small perturbations are often attributed to the 10 existence of unstable modes. In the limit of long times, the ?rst normal mode (least damped mode) dominates the response. The above classical stability... for the linear case. Recently, Neumaier and Schneider (2001) developed a procedure to estimate eigen- modes of high order autoregressive (AR) models, while (2.3) is basically an AR(1) model. Traditionally, the least damped eigenmodes are considered to be the most...

  15. Decadal climate predictions using sequential learning algorithms

    E-Print Network [OSTI]

    Strobach, Ehud

    2015-01-01

    Ensembles of climate models are commonly used to improve climate predictions and assess the uncertainties associated with them. Weighting the models according to their performances holds the promise of further improving their predictions. Here, we use an ensemble of decadal climate predictions to demonstrate the ability of sequential learning algorithms (SLAs) to reduce the forecast errors and reduce the uncertainties. Three different SLAs are considered, and their performances are compared with those of an equally weighted ensemble, a linear regression and the climatology. Predictions of four different variables--the surface temperature, the zonal and meridional wind, and pressure--are considered. The spatial distributions of the performances are presented, and the statistical significance of the improvements achieved by the SLAs is tested. Based on the performances of the SLAs, we propose one to be highly suitable for the improvement of decadal climate predictions.

  16. ICRCCM Phase 2: Verification and calibration of radiation codes in climate models

    SciTech Connect (OSTI)

    Ellingson, R.G.; Wiscombe, W.J.; Murcray, D.; Smith, W.; Strauch, R.

    1992-01-01

    Following the finding by the InterComparison of Radiation Codes used in Climate Models (ICRCCM) of large differences among fluxes predicted by sophisticated radiation models that could not be sorted out because of the lack of a set of accurate atmospheric spectral radiation data measured simultaneously with the important radiative properties of the atmosphere, our team of scientists proposed to remedy the situation by carrying out a comprehensive program of measurement and analysis called SPECTRE (Spectral Radiance Experiment). The data collected during SPECTRE form the test bed for the second phase of ICRCCM, namely verification and calibration of radiation codes used in climate models. This should lead to more accurate radiation models for use in parameterizing climate models, which in turn play a key role in the prediction of trace-gas greenhouse effects. This report summarizes the activities of our group during the project's Third year to meet our stated objectives. The report is divided into three sections entitled: SPECTRE Activities, ICRCCM Activities, and summary information. The section on SPECTRE activities summarizes the field portion of the project during 1991, and the data reduction/analysis performed by the various participants. The section on ICRCCM activities summarizes our initial attempts to select data for distribution to ICRCCM participants and at comparison of observations with calculations as will be done by the ICRCCM participants. The Summary Information section lists data concerning publications, presentations, graduate students supported, and post-doctoral appointments during the project.

  17. A Global Climate Model Agent for High Spatial and Temporal Resolution Data

    SciTech Connect (OSTI)

    Wood, Lynn S.; Daily, Jeffrey A.; Henry, Michael J.; Palmer, Bruce J.; Schuchardt, Karen L.; Dazlich, Donald A.; Heikes, Ross P.; Randall, David

    2015-02-01

    Fine cell granularity in modern climate models can produce terabytes of data in each snapshot, causing significant I/O overhead. To address this issue, a method of reducing the I/O latency of high-resolution climate models by identifying and selectively outputting regions of interest is presented. Working with a Global Cloud Resolving Model and running with up to 10240 processors on a Cray XE6, this method provides significant I/O bandwidth reduction depending on the frequency of writes and size of the region of interest. The implementation challenges of determining global parameters in a strictly core-localized model and properly formatting output files that only contain subsections of the global grid are addressed, as well as the overall bandwidth impact and benefits of the method. The gains in I/O throughput provided by this method allow dual output rates for high-resolution climate models: a low-frequency global snapshot as well as a high-frequency regional snapshot when events of particular interest occur.

  18. 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

    2008-01-01

    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.

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

    SciTech Connect (OSTI)

    Maurakis, Eugene G

    2010-10-01

    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.

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

    E-Print Network [OSTI]

    Subin, Z.M.

    2013-01-01

    light extinction on thermal stratification in reservoirs andresponse of the thermal stratification of South Bay (Lakedepth, increasing thermal stratification and decreasing the

  1. 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.

    1994-01-01

    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 ...

  2. Heat and freshwater exchange on the Antarctic continental1" shelf in a regional coupled climate model2"

    E-Print Network [OSTI]

    Gerber, Edwin

    Heat and freshwater exchange on the Antarctic continental1" shelf in a regional coupled climate, South Korea 120-749. Email:21" cyoo@cims.nyu.edu.22" #12;2" Abstract23" Understanding heat. This study analyzes the heat and freshwater budget using a regional25" coupled climate model, which has been

  3. 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)

    2012-07-01

    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 Ĺ 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 Ĺ r.m.s.d. representing 65–100% of the structure.

  4. 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.

    2013-09-01

    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.

  5. 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

    2013-07-24

    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.

  6. An Improved Procedure for Developing Calibrated Hourly Simulation Models 

    E-Print Network [OSTI]

    Bou-Saada, T. E.; Haberl, J. S.

    1995-01-01

    . REFERENCES Abbas, M. 1993. Development of graphical indices for building energy data, M.S. Thesis, Energy Systems Rpt No. ESL-TH-93/12-02, Texas A&M University, College Station, TX. ASHRAE. 1991. ASHRAE handbook: 1991 HVAC applications volume. American... Support Office, University of Illinois Urbana-Champaign. Bou-Saada, T.E. 1994a. An improved procedure for developing a calibrated hourly simulation model of an electrically heated and cooled commercial building, M.S. Thesis, Energy Systems Rpt No. ESL- TH...

  7. 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.

    2008-04-15

    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.

  8. 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

    2015-01-01

    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...

  9. Flooding Experiments and Modeling for Improved Reactor Safety

    SciTech Connect (OSTI)

    Solmos, M., Hogan, K.J., VIerow, K.

    2008-09-14

    Countercurrent two-phase flow and “flooding” phenomena in light water reactor systems are being investigated experimentally and analytically to improve reactor safety of current and future reactors. The aspects that will be better clarified are the effects of condensation and tube inclination on flooding in large diameter tubes. The current project aims to improve the level of understanding of flooding mechanisms and to develop an analysis model for more accurate evaluations of flooding in the pressurizer surge line of a Pressurized Water Reactor (PWR). Interest in flooding has recently increased because Countercurrent Flow Limitation (CCFL) in the AP600 pressurizer surge line can affect the vessel refill rate following a small break LOCA and because analysis of hypothetical severe accidents with the current flooding models in reactor safety codes shows that these models represent the largest uncertainty in analysis of steam generator tube creep rupture. During a hypothetical station blackout without auxiliary feedwater recovery, should the hot leg become voided, the pressurizer liquid will drain to the hot leg and flooding may occur in the surge line. The flooding model heavily influences the pressurizer emptying rate and the potential for surge line structural failure due to overheating and creep rupture. The air-water test results in vertical tubes are presented in this paper along with a semi-empirical correlation for the onset of flooding. The unique aspects of the study include careful experimentation on large-diameter tubes and an integrated program in which air-water testing provides benchmark knowledge and visualization data from which to conduct steam-water testing.

  10. Use of Climate Data in Climate Research

    E-Print Network [OSTI]

    von Storch, Hans

    Use of Climate Data in Climate Research A Random Walk Through the MPI Hans von Storch Max and Technical Committee of the Global Climate Observing System in Hamburg, Germany September 19 - 22, 1994 #12;For which- Purposes do we Use 0bserved Data · Climate modelling - Design of parameterisations

  11. CLIMATE VARIABILITY, CLIMATE CHANGE, AND WESTERN

    E-Print Network [OSTI]

    Keeton, William S.

    CHAPTER 13 CLIMATE VARIABILITY, CLIMATE CHANGE, AND WESTERN WILDFIRE WITH IMPLICATIONS FOR THE URBAN­WILDLAND INTERFACE William S. Keeton, Philip W. Mote and Jerry F. Franklin ABSTRACT Climate change hazards by the warmer, drier summers projected for much of the western U.S. by climate models would

  12. Sensitivity of a global climate model to the critical Richardson number in the boundary layer parameterization

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

    Zhang, Ning; Liu, Yangang; Gao, Zhiqiu; Li, Dan

    2015-04-27

    The critical bulk Richardson number (Ricr) is an important parameter in planetary boundary layer (PBL) parameterization schemes used in many climate models. This paper examines the sensitivity of a Global Climate Model, the Beijing Climate Center Atmospheric General Circulation Model, BCC_AGCM to Ricr. The results show that the simulated global average of PBL height increases nearly linearly with Ricr, with a change of about 114 m for a change of 0.5 in Ricr. The surface sensible (latent) heat flux decreases (increases) as Ricr increases. The influence of Ricr on surface air temperature and specific humidity is not significant. The increasingmore »Ricr may affect the location of the Westerly Belt in the Southern Hemisphere. Further diagnosis reveals that changes in Ricr affect stratiform and convective precipitations differently. Increasing Ricr leads to an increase in the stratiform precipitation but a decrease in the convective precipitation. Significant changes of convective precipitation occur over the inter-tropical convergence zone, while changes of stratiform precipitation mostly appear over arid land such as North Africa and Middle East.« less

  13. On the characteristics of aerosol indirect effect based on dynamic regimes in global climate models

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

    Zhang, S.; Wang, M.; Ghan, S. J.; Ding, A.; Wang, H.; Zhang, K.; Neubauer, D.; Lohmann, U.; Ferrachat, S.; Takeamura, T.; et al

    2015-09-02

    Aerosol-cloud interactions continue to constitute a major source of uncertainty for the estimate of climate radiative forcing. The variation of aerosol indirect effects (AIE) in climate models is investigated across different dynamical regimes, determined by monthly mean 500 hPa vertical pressure velocity (?500), lower-tropospheric stability (LTS) and large-scale surface precipitation rate derived from several global climate models (GCMs), with a focus on liquid water path (LWP) response to cloud condensation nuclei (CCN) concentrations. The LWP sensitivity to aerosol perturbation within dynamic regimes is found to exhibit a large spread among these GCMs. It is in regimes of strong large-scale ascendmore »(?500 ?1) and low clouds (stratocumulus and trade wind cumulus) where the models differ most. Shortwave aerosol indirect forcing is also found to differ significantly among different regimes. Shortwave aerosol indirect forcing in ascending regimes is as large as that in stratocumulus regimes, which indicates that regimes with strong large-scale ascend are as important as stratocumulus regimes in studying AIE. It is further shown that shortwave aerosol indirect forcing over regions with high monthly large-scale surface precipitation rate (> 0.1 mm d?1) contributes the most to the total aerosol indirect forcing (from 64 to nearly 100 %). Results show that the uncertainty in AIE is even larger within specific dynamical regimes than that globally, pointing to the need to reduce the uncertainty in AIE in different dynamical regimes.« less

  14. Impact of Emissions, Chemistry, and Climate on Atmospheric Carbon Monoxide: 100-year Predictions from a Global Chemistry-Climate Model

    E-Print Network [OSTI]

    of methane and the production of CO2, ozone, and sulfate aerosols and thus affects climate, while, producing formaldehyde (CH2O) and then carbon monoxide. This methane reaction, in combination with R1

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

    SciTech Connect (OSTI)

    Gharagozloo, Patricia E.; Drewry, Jessica L.

    2013-01-01

    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.

  17. 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

    2014-09-23

    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.

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

    SciTech Connect (OSTI)

    Not Available

    2013-11-01

    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.

  19. An Analogue Approach to Identify Extreme Precipitation Events: Evaluation and Application to CMIP5 Climate Models in the United States

    E-Print Network [OSTI]

    Gao, Xiang

    Global warming is expected to alter the frequency, intensity, and risk of extreme precipitation events. However, global climate models in general do not correctly reproduce the frequency and intensity distribution of ...

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

    E-Print Network [OSTI]

    Collier, Jonathan Craig

    2005-11-01

    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, ...

  1. Investigation of the Summer Climate of the Contiguous United States and Mexico Using the Regional Atmospheric Modeling System (RAMS).

    E-Print Network [OSTI]

    Castro, Christopher L.

    to observations. The Great Plains low-level jet (LLJ) is also well represented in both RAMS and NARR, but the Baja Atmospheric Modeling System (RAMS). Part I: Model Climatology (1950­2002) CHRISTOPHER L. CASTRO* Department downscaled using the Regional Atmospheric Modeling System (RAMS) to generate a regional climate model (RCM

  2. 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

    2015-01-01

    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.

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

    SciTech Connect (OSTI)

    Tidwell, Vincent C.; Sue Tillery; Phillip King

    2008-09-01

    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.

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

    SciTech Connect (OSTI)

    Zhang, Guang J [Scripps Institution of Oceanography

    2013-07-29

    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.

  5. Incorporating Urban Systems in Global Climate Models: The Role of GIScience

    E-Print Network [OSTI]

    Feddema, Johannes J.

    2006-11-15

    city with H/W=0.5,?,3.0 Simulated Urban Heat Island ? NCEP atmospheric forcing ? Rural grassland ? Default city with H/W=0.5,?,3.0 With Q f Without Q f Variability in Simulated Heat Island caused by Climate and Rural Environment ?Atmospheric forcing... from CAM (offline model) ?Default city with H/W=0.5,?,3.0 ?Rural environment from CLM Surface Data Model Validation: ? At a given height to width ratio, a wide range of heat islands is simulated depending on prevailing meteorological conditions...

  6. Modeling U.S. Energy Use Changes with Global Climate Change

    SciTech Connect (OSTI)

    Hadley, Stanton W; Erickson III, David J; Hernandez Figueroa, Jose L

    2006-09-01

    Using a general circulation model of Earth climate (PCM-IBIS) to drive an energy use model (DD-NEMS), we calculated the energy use changes for each year from 2003-2025 for the nine U.S. Census regions. We used five scenarios: 1) a reference with no change in temperatures from the 1970-2003 average, 2) a gradual 1 F rise in temperature by 2025, 3) a gradual 3 F rise by 2025, 4) a climate simulation with low temperature response to CO2 doubling in the atmosphere, and 5) a climate simulation with a more extreme response. The low-?T scenario had a cumulative reduction in energy of 2.1 Quads but an increase in cost of $14.8 billion. The northern states had reductions in cost over the entire period, but most other regions had increases in costs because increases in cooling costs outweighed reductions in heating and other energy uses. Higher temperature sensitivity resulted in increased warming, especially in the winter months. Because heating needs decreased, total energy requirements declined by a cumulative 4.2 Quads. However, total cost still increased $6.1 billion and carbon emissions still rose as coal-based electricity for cooling needs grew.

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

    E-Print Network [OSTI]

    Rabin, Gregory S

    2007-01-01

    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 ...

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

    SciTech Connect (OSTI)

    Vierow, Karen

    2008-09-26

    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.

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

    SciTech Connect (OSTI)

    Morrison, PI Hugh

    2012-09-21

    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).

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

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

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

    2015-05-19

    The mineral dust cycle responds to climate variations and plays an important role in the climate system by affecting the radiative balance of the atmosphere and modifying biogeochemistry. Polar ice cores provide unique information about deposition of aeolian dust particles transported over long distances. These cores are a palaeoclimate proxy archive of climate variability thousands of years ago. The current study is a first attempt to simulate past interglacial dust cycles with a global aerosol–climate model ECHAM5-HAM. The results are used to explain the dust deposition changes in Antarctica in terms of quantitative contribution of different processes, such as emission,more »atmospheric transport and precipitation, which will help to interpret palaeodata from Antarctic ice cores. The investigated periods include four interglacial time slices: the pre-industrial control (CTRL), mid-Holocene (6000 yr BP; hereafter referred to as \\"6 kyr\\"), last glacial inception (115 000 yr BP; hereafter \\"115 kyr\\") and Eemian (126 000 yr BP; hereafter \\"126 kyr\\"). One glacial time interval, the Last Glacial Maximum (LGM) (21 000 yr BP; hereafter \\"21 kyr\\"), was simulated as well to be a reference test for the model. Results suggest an increase in mineral dust deposition globally, and in Antarctica, in the past interglacial periods relative to the pre-industrial CTRL simulation. Approximately two-thirds of the increase in the mid-Holocene and Eemian is attributed to enhanced Southern Hemisphere dust emissions. Slightly strengthened transport efficiency causes the remaining one-third of the increase in dust deposition. The moderate change in 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. Maximum dust deposition in Antarctica was simulated for the glacial period. LGM dust deposition in 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 climates.« less

  11. 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

    2015-01-01

    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...

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

    ScienceCinema (OSTI)

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

    2010-09-01

    In the last 100 years, the Earth has warmed by about 1şF, 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.

  13. 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

    2010-05-12

    In the last 100 years, the Earth has warmed by about 1şF, 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.

  14. 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 ...

  15. Adjusting to policy expectations in climate change modeling : an interdiciplinary study of flux adjustments in coupled atmosphere-ocean general circulation models

    E-Print Network [OSTI]

    Shackley, Simon.; Risbey, James; Stone, Peter H.; Wynne, Brian

    This paper surveys and interprets the attitudes of scientists to the use of flux adjustments in climate projections with coupled Atmosphere Ocean General Circulation Models. The survey is based largely on the responses of ...

  16. 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.

    2011-11-01

    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.

  17. CRED: A New Model of Climate and Development | 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 on Google Bookmark EERE: Alternative Fuels Data Center Home Page on QA:QA J-E-1 SECTION J APPENDIX ECoopButte County, California: Energy ResourcesCRED: A New Model of Climate and

  18. Implementation and evaluation of online gas-phase chemistry within a regional climate model (RegCM-CHEM4)

    SciTech Connect (OSTI)

    Shalaby, A. K.; Zakey, A. S.; Tawfik, A. B.; Solmon, F.; Giorgi, Filippo; Stordal, F.; Sillman, S.; Zaveri, Rahul A.; Steiner, A. L.

    2012-05-22

    The RegCM-CHEM4 is a new online climate-chemistry model based on the International Centre for Theoretical Physics (ICTP) regional climate model (RegCM4). Tropospheric gas-phase chemistry is integrated into the climate model using the condensed version of the Carbon Bond Mechanism (CBM-Z; Zaveri and Peters, 1999) with a fast solver based on radical balances. We evaluate the model over Continental Europe for two different time scales: (1) an event-based analysis of the ozone episode associated with the heat wave of August 2003 and (2) a climatological analysis of a sixyear simulation (2000-2005). For the episode analysis, model simulations show good agreement with European Monitoring and Evaluation Program (EMEP) observations of hourly ozone over different regions in Europe and capture ozone concentrations during and after the August 2003 heat wave event. For long-term climate simulations, the model captures the seasonal cycle of ozone concentrations with some over prediction of ozone concentrations in non-heat wave summers. Overall, the ozone and ozone precursor evaluation shows the feasibility of using RegCM-CHEM4 for decadal-length simulations of chemistry-climate interactions.

  19. 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.

    2014-12-01

    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.

  20. Using Land to Mitigate Climate Change: Hitting the Target, Recognizing the Trade-offs

    E-Print Network [OSTI]

    model, the Program seeks to: discover new interactions among natural and human climate system components that will shape our future; and improve methods to model, monitor and verify greenhouse gas emissions and climatic environmental conditions there may be implications for food prices. Using an integrated global system model, we

  1. Model of calcareous deposit formation on cathodically protected steel in seawater: improvements and extensions 

    E-Print Network [OSTI]

    Blackburne, Patricia Nicole

    1996-01-01

    A mathematical model of calcareous deposits on cathodically protected steel in seawater has been improved for practical applications. The model can be used in industry and as a pedagogical tool. The model extracts useful information from National...

  2. 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

  3. Recent carbonate sedimentation on Balearic platform: model for temperate-climate carbonate shelves

    SciTech Connect (OSTI)

    Fornos, J.; Rodriguez-Perea, A.; Massuti, C.; Pomar, L.; Acosta, J.; Herranz, P.; Sanz, J.L.

    1989-03-01

    Existing models for carbonate sedimentation on continental platforms are derived from the study of modern carbonate platforms in tropical climates. The Balearic platform in the western Mediterranean provides a new model for carbonate sedimentation in a temperature, semiarid climate. On most of the continental shelf around the Balearic Islands, modern sediments are exclusively bioclastic carbonates. Shoreline carbonate sediments are bioclastic sands and muds accumulating in beach-dune systems without significant tidal influence (there are no astronomical tides in the western Mediterranean ). From the upper shoreface to 35 m deep, the sandy bottom is extensively colonized by sea grass (Posidonia oceanica), the rhizomes and roots of which form a rigid entrapment that retains the sediment derived from calcareous organisms living within the sea grass and from calcareous epiphytes living on the stems and leaves. Archeological dating establishes a rate of vertical accretion in this zone of 10/sup 3/ Bubnoff units (1 Bubnoff unit = 1 mm/1000 years). Between depths of 40 and 60 m, carbonate sands are composed predominantly or red-algal fragments. Intensely bioturbated wave ripples occur in environments dominated by laminar red algae (Lithothamnium and Phymatolithon). Below depths of 60 m, coarse sediment produced by rhodolitic and ramose red algae is deposited in areas of tens to hundreds of meters in size. Biogenic buildups up to 2 m high occur in sandy areas as well as in deeper muddy areas. At the same depth in open-platform zones, the bottom topography is characterized by large hummocks several hundred meters across. From the horizontal distribution of facies, it is possible to construct the probable vertical sequence of lithofacies which would characterize carbonates accumulating on a temperate-climate carbonate shelf. Many of these lithofacies are recognized in upper Miocene limestones on the Balearic Islands.

  4. The 'why' of models | ornl.gov

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

    of Agricultural Sciences. The study is published in Nature Climate Change as "Using ecosystem experiments to improve vegetation models." The ORNL research was supported by...

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

    E-Print Network [OSTI]

    Lines, Emily

    2012-06-12

    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...

  6. 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.

    2013-01-01

    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.

  7. 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.

    2014-05-13

    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.

  8. 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

  9. Preindustrial to present-day changes in tropospheric hydroxyl radical and methane lifetime from the Atmospheric Chemistry and Climate Model Intercomparison Project (ACCMIP)

    E-Print Network [OSTI]

    2013-01-01

    hindcasts of atmospheric chemistry: the role of meteorology,J. : Introduction to atmospheric chemistry, Princeton Uni-and Zeng, G. : The Atmospheric Chemistry and Climate Model

  10. 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

    2013-03-18

    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.

  11. Can Fully Accounting for Clouds in Data Assimilation Improve Short-Term Forecasts by Global Models?

    E-Print Network [OSTI]

    Robert, Pincus

    ? ROBERT PINCUS AND ROBERT J. PATRICK HOFMANN University of Colorado and NOAA/Earth System Research for Atmospheric Research, Boulder, Colorado JEFFREY S. WHITAKER NOAA/Earth Systems Research Laboratory using a single ensemble data assimilation system coupled to two present-generation climate models

  12. 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

  13. Modeling the climate impact of Southern Hemisphere ozone depletion: The importance

    E-Print Network [OSTI]

    MacDonald, Mark

    Processes and their Role in Climate (SPARC)) used by many Intergovernmental Panel on Climate Change Fifth/summer polar cap cooling, geopotential height decreases, and zonal wind increases in the BDBP simulations

  14. Integrated Drought Modeling For Texas Under Climate Change Impact With Implications For Water Resources Planning 

    E-Print Network [OSTI]

    Rajsekhar, Deepthi

    2014-12-02

    Drought is a deficiency in the hydro climatic variable of interest that is experienced for an extended period of time. In many parts of the world, it is a normal, recurring feature of climate and is therefore inevitable. Adequate monitoring...

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

    E-Print Network [OSTI]

    Huybers, Peter, 1974-

    2004-01-01

    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 ...

  16. Downscaling CMIP5 climate models shows increased tropical cyclone activity over the 21st century

    E-Print Network [OSTI]

    Emanuel, Kerry Andrew

    A recently developed technique for simulating large [O(10[superscript 4])] numbers of tropical cyclones in climate states described by global gridded data is applied to simulations of historical and future climate states ...

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

    E-Print Network [OSTI]

    Reilly, John M.

    1993-01-01

    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 ...

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

    E-Print Network [OSTI]

    Dunlop, Mary

    2012-01-01

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

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

    E-Print Network [OSTI]

    Dunlop, Mary

    2012-01-01

    for improving microbial biofuel production using a synthetica model for microbial biofuel production where a syntheticloop that limits biofuel production. These toxic effects may

  20. Improving Face Recognition Performance Using a Hierarchical Bayesian Model

    E-Print Network [OSTI]

    Shikaripur Nadig, Ashwini

    2010-04-27

    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. Modelling prominence and emphasis improves unit-selection synthesis 

    E-Print Network [OSTI]

    Strom, Volker; Nenkova, Ani; Clark, Robert A J; Vazquez-Alvarez, Yolanda; Brenier, Jason; King, Simon; Jurafsky, Daniel

    2007-01-01

    We describe the results of large scale perception experiments showing improvements in synthesising two distinct kinds of prominence: standard pitch-accent and strong emphatic accents. Previously prominence assignment has ...

  2. 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

    2015-01-01

    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.

  3. Detection and Attribution of Regional Climate Change

    SciTech Connect (OSTI)

    Bala, G; Mirin, A

    2007-01-19

    We developed a high resolution global coupled modeling capability to perform breakthrough studies of the regional climate change. The atmospheric component in our simulation uses a 1{sup o} latitude x 1.25{sup o} longitude grid which is the finest resolution ever used for the NCAR coupled climate model CCSM3. Substantial testing and slight retuning was required to get an acceptable control simulation. The major accomplishment is the validation of this new high resolution configuration of CCSM3. There are major improvements in our simulation of the surface wind stress and sea ice thickness distribution in the Arctic. Surface wind stress and ocean circulation in the Antarctic Circumpolar Current are also improved. Our results demonstrate that the FV version of the CCSM coupled model is a state of the art climate model whose simulation capabilities are in the class of those used for IPCC assessments. We have also provided 1000 years of model data to Scripps Institution of Oceanography to estimate the natural variability of stream flow in California. In the future, our global model simulations will provide boundary data to high-resolution mesoscale model that will be used at LLNL. The mesoscale model would dynamically downscale the GCM climate to regional scale on climate time scales.

  4. Global air quality and climate

    E-Print Network [OSTI]

    2012-01-01

    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.

  5. A comparison of neural network and processbased models for vegetation distribution under global climate change

    E-Print Network [OSTI]

    climate change Eric Chown chown@cs.orst.edu Thomas G. Dietterich tgd@cs.orst.edu Department of Computer covering current climate and vegetation distribution in the coterminous United States. Completely automated on two tasks: prediction of current vegetation distribution given current climate and prediction

  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

    2013-01-17

    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. Synthesis of Remote Sensing and Field Observations to Model and Understand Disturbance and Climate Effects on the Carbon Balance of Oregon & Northern California

    SciTech Connect (OSTI)

    Beverly Law; David Turner; Warren Cohen; Mathias Goeckede

    2008-05-22

    The goal is to quantify and explain the carbon (C) budget for Oregon and N. California. The research compares "bottom -up" and "top-down" methods, and develops prototype analytical systems for regional analysis of the carbon balance that are potentially applicable to other continental regions, and that can be used to explore climate, disturbance and land-use effects on the carbon cycle. Objectives are: 1) Improve, test and apply a bottom up approach that synthesizes a spatially nested hierarchy of observations (multispectral remote sensing, inventories, flux and extensive sites), and the Biome-BGC model to quantify the C balance across the region; 2) Improve, test and apply a top down approach for regional and global C flux modeling that uses a model-data fusion scheme (MODIS products, AmeriFlux, atmospheric CO2 concentration network), and a boundary layer model to estimate net ecosystem production (NEP) across the region and partition it among GPP, R(a) and R(h). 3) Provide critical understanding of the controls on regional C balance (how NEP and carbon stocks are influenced by disturbance from fire and management, land use, and interannual climate variation). The key science questions are, "What are the magnitudes and distributions of C sources and sinks on seasonal to decadal time scales, and what processes are controlling their dynamics? What are regional spatial and temporal variations of C sources and sinks? What are the errors and uncertainties in the data products and results (i.e., in situ observations, remote sensing, models)?

  8. 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.

    2014-05-01

    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.

  9. Improving the Performance of a Dutch CSR by Modeling Pronunciation Variation 

    E-Print Network [OSTI]

    Wester, Mirjam; Kessens, Judith M; Strik, Helmer

    This paper describes how the performance of a continuous speech recognizer for Dutch has been improved by modeling pronunciation variation. We used three methods in order to model pronunciation variation. First, within-word ...

  10. Development of an equipment management model to improve effectiveness of processes

    SciTech Connect (OSTI)

    Chang, H. S.; Ju, T. Y.; Song, T. Y.

    2012-07-01

    The nuclear industries have developed and are trying to create a performance model to improve effectiveness of the processes implemented at nuclear plants in order to enhance performance. Most high performing nuclear stations seek to continually improve the quality of their operations by identifying and closing important performance gaps. Thus, many utilities have implemented performance models adjusted to their plant's configuration and have instituted policies for such models. KHNP is developing a standard performance model to integrate the engineering processes and to improve the inter-relation among processes. The model, called the Standard Equipment Management Model (SEMM), is under development first by focusing on engineering processes and performance improvement processes related to plant equipment used at the site. This model includes performance indicators for each process that can allow evaluating and comparing the process performance among 21 operating units. The model will later be expanded to incorporate cost and management processes. (authors)

  11. An improved structural mechanics model for the FRAPCON nuclear fuel performance code

    E-Print Network [OSTI]

    Mieloszyk, Alexander James

    2012-01-01

    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 ...

  12. Vapor intrusion modeling : limitations, improvements, and value of information analyses

    E-Print Network [OSTI]

    Friscia, Jessica M. (Jessica Marie)

    2014-01-01

    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 ...

  13. CFD modeling of entrained-flow coal gasifiers with improved physical and chemical sub-models

    SciTech Connect (OSTI)

    Ma, J.; Zitney, S.

    2012-01-01

    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.

  14. Design report on SCDAP/RELAP5 model improvements - debris bed and molten pool behavior

    SciTech Connect (OSTI)

    Allison, C.M.; Rempe, J.L.; Chavez, S.A.

    1994-11-01

    the SCDAP/RELAP5/MOD3 computer code is designed to describe the overall reactor coolant system thermal-hydraulic response, core damage progression, and in combination with VICTORIA, fission product release and transport during severe accidents. Improvements for existing debris bed and molten pool models in the SCDAP/RELAP5/MOD3.1 code are described in this report. Model improvements to address (a) debris bed formation, heating, and melting; (b) molten pool formation and growth; and (c) molten pool crust failure are discussed. Relevant data, existing models, proposed modeling changes, and the anticipated impact of the changes are discussed. Recommendations for the assessment of improved models are provided.

  15. 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

    2009-01-10

    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.

  16. Crisis of the Chaotic Attractor of a Climate Model: A Transfer Operator Approach

    E-Print Network [OSTI]

    Alexis Tantet; Valerio Lucarini; Frank Lunkeit; Henk A. Dijkstra

    2015-07-08

    The destruction of a chaotic attractor leading to a rough change in the dynamics of a system as a control parameter is smoothly varied is studied. While bifurcations involving non-chaotic invariant sets, such as fixed points or periodic orbits, can be characterised by a Lyapunov exponent crossing the imaginary axis, little is known about the changes in a chaotic attractor during a crisis. The statistical physics framework, is particularly well suited for the study of global properties of chaotic systems. In particular, the semigroup of transfer operators governing the finite time evolution of probability distributions in phase space and its spectrum characterises both the relaxation rate of distributions to a statistical steady-state and the stability of this steady-state to perturbations. If critical slowing down indeed occurs in the approach to an attractor crisis, the gap in the spectrum (between the leading eigenvalue and the secondary ones) of the semigroup is expected to shrink. Here we use a high-dimensional, chaotic climate model system in which a transition from today's warm climate state to a snow-covered state occurs. This transition is associated with the destruction of a chaotic attractor as the solar constant is decreased. We show that critical slowing down develops in this model before the destruction of the chaotic attractor and that it can be observed from trajectories along the attractor. In addition, we demonstrate that the critical slowing down can be traced back to the shrinkage of the leading eigenvalues of coarse-grained approximations of the transfer operators and that these eigenvalues capture the fundamental features of the attractor crisis.

  17. 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

  18. An Urban Parameterization for a Global Climate Model. Part II: Sensitivity to Input Parameters and the Simulated Urban Heat Island in Offline Simulations

    E-Print Network [OSTI]

    Oleson, Keith W.; Bonan, Gordon B.; Feddema, Johannes J.; Vertenstein, M.

    2008-01-01

    -Type text/plain; charset=UTF-8 An Urban Parameterization for a Global Climate Model. Part II: Sensitivity to Input Parameters and the Simulated Urban Heat Island in Offline Simulations K. W. OLESON AND G. B. BONAN Climate and Global Dynamics... Model. Here the robustness of the model is tested through sensitivity studies and the model’s ability to simulate urban heat islands in different environments is evaluated. Findings show that heat storage and sensible heat flux are most sensitive...

  19. 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

  20. 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)

    2013-01-01

    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 ...

  1. Improved atmosphere-ocean coupled modeling in the tropics for climate

    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: Alternative Fuels Data Center Homesum_a_epg0_fpd_mmcf_m.xls" ,"Available from WebQuantity of NaturalDukeWakefieldSulfate Reducing(Journal Article)lasers(Journal Article)Curves (Journal Article)Connect

  2. Improved atmosphere-ocean coupled modeling in the tropics for climate

    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: Alternative Fuels Data Center Homesum_a_epg0_fpd_mmcf_m.xls" ,"Available from WebQuantity of NaturalDukeWakefieldSulfate Reducing(Journal Article)lasers(Journal Article)Curves (Journal Article)Connectprediction

  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: Alternative Fuels Data Center Homesum_a_epg0_fpd_mmcf_m.xls" ,"Available from WebQuantityBonneville Power AdministrationRobust,Field-effectWorking With WIPPfinalUnexpectedofWykoW03:Connect Uses of antimicrobial

  4. LASSO: Tying ARM Data and LES Modeling Together to Improve Climate Science

    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: Alternative Fuels Data Center Homesum_a_epg0_fpd_mmcf_m.xls" ,"Available from WebQuantityBonneville Power Administration would likeUniverseIMPACTThousand CubicResource and Job EventpopLA TexturePresentations atLASSO:

  5. Incorporation of a physically based melt pond scheme into the sea ice component of a climate model

    E-Print Network [OSTI]

    Feltham, Daniel

    Incorporation of a physically based melt pond scheme into the sea ice component of a climate model and evolution of melt ponds. Melt ponds accumulate on the surface of sea ice from snow and sea ice melt, melt ponds cover up to 50% of the sea ice surface. We have developed a melt pond evolution theory. Here

  6. Modeling the Cost of Climate Policy: Distinguishing Between Alternative Cost Deftitions and Long-Run Cost Dynamics

    E-Print Network [OSTI]

    Modeling the Cost of Climate Policy: Distinguishing Between Alternative Cost Deftitions and Long. There are alternative definitions of cost and the evolution of technologies and preferences is a complex and highly, some are more useful." To be more useful, The Energy Journal, Vol. 24, No. 1. CopyrightQ2003

  7. Diagnosing Northern Hemisphere Jet Portrayal in 17 CMIP3 Global Climate Models: Twenty-First-Century Projections

    E-Print Network [OSTI]

    Wisconsin at Madison, University of

    an intensified midlatitude jet stream and an elevated tropopause, as well as a poleward-shifted jet. While both to impact modeled Northern Hemisphere jet stream changes. In particular, El Nin~o­Southern Oscillation in the Northern Hemisphere zonal wind response to climate change. 1. Background Understanding how jet streams

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

    E-Print Network [OSTI]

    Yang, Zhenyu

    . As a typical modern and large-sized stable system, the considered stable uses hybrid ventilation and low described. The models for air inlets, outlets and their driving systems as well as the heating systems, one climate control systems. A typical modern stable system is usually equipped with a hybrid ventilation [3

  9. 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

  10. Improving Air-Conditioner and Heat Pump Modeling

    SciTech Connect (OSTI)

    Winkler, Jon

    2012-03-02

    This presentation describes a new approach to modeling residential air conditioners and heat pumps, which 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.

  11. Improving Air-Conditioner and Heat Pump Modeling (Presentation)

    SciTech Connect (OSTI)

    Winkler, J.

    2012-03-01

    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.

  12. 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.

    2006-10-01

    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.

  13. 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

    2005-08-01

    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.

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

    SciTech Connect (OSTI)

    Eric T. DeWeaver

    2010-02-17

    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.

  15. Stochastic Parameterization for Light Absorption by Internally Mixed BC/dust in Snow Grains for Application to Climate Models

    SciTech Connect (OSTI)

    Liou, K. N.; Takano, Y.; He, Cenlin; Yang, P.; Leung, Lai-Yung R.; Gu, Y.; Lee, W- L.

    2014-06-27

    A stochastic approach to model the positions of BC/dust internally mixed with two snow-grain types has been developed, including hexagonal plate/column (convex) and Koch snowflake (concave). Subsequently, light absorption and scattering analysis can be followed by means of an improved geometric-optics approach coupled with Monte Carlo photon tracing to determine their single-scattering properties. For a given shape (plate, Koch snowflake, spheroid, or sphere), internal mixing absorbs more light than external mixing. The snow-grain shape effect on absorption is relatively small, but its effect on the asymmetry factor is substantial. Due to a greater probability of intercepting photons, multiple inclusions of BC/dust exhibit a larger absorption than an equal-volume single inclusion. The spectral absorption (0.2 – 5 um) for snow grains internally mixed with BC/dust is confined to wavelengths shorter than about 1.4 um, beyond which ice absorption predominates. Based on the single-scattering properties determined from stochastic and light absorption parameterizations and using the adding/doubling method for spectral radiative transfer, we find that internal mixing reduces snow albedo more than external mixing and that the snow-grain shape plays a critical role in snow albedo calculations through the asymmetry factor. Also, snow albedo reduces more in the case of multiple inclusion of BC/dust compared to that of an equal-volume single sphere. For application to land/snow models, we propose a two-layer spectral snow parameterization containing contaminated fresh snow on top of old snow for investigating and understanding the climatic impact of multiple BC/dust internal mixing associated with snow grain metamorphism, particularly over mountains/snow topography.

  16. 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...

  17. Knowledge Graphs as Context Models: Improving the Detection of

    E-Print Network [OSTI]

    Rosso, Paolo

    character n-gram (CL-CNG) model [9] which is based on the syntax of docu- ments, which uses character n among them. Some of these models have been compared in detecting CL plagiarism in [14]. CL-ASA and CL-CNG

  18. Security Analysis and Improvement Model for Web-based Applications 

    E-Print Network [OSTI]

    Wang, Yong

    2010-01-14

    to the current states in software systems and hardware systems, and independent of web application system states in the past. Therefore, the web-based applications can be approximately modeled by the Markov Process Model. The web-based applications can...

  19. 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 ...

  20. Improving Energy Efficiency by Developing Components for Distributed Cooling and Heating Based on Thermal Comfort Modeling[Thermoelectric (TE) HVAC

    Broader source: Energy.gov [DOE]

    Discusses results from TE HVAC project to add detail to a human thermal comfort model and further allow load reduction in the climate control energy through a distributed TE network

  1. 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.

    2014-01-01

    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.

  2. 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

    2007-03-01

    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.

  3. Analysis of Cooling Regression Models for Hot and Humid Climates Based on "Operational Effective Enthalpy 

    E-Print Network [OSTI]

    Li, X.; Baltazar, J. C.

    2013-01-01

    determination for energy efficiency projects is based on procedures established in the International Performance Measurement and Verification Protocol (IPMVP, 2012), specifically Option C. Energy use baseline models are developed from a regression analysis... constitute a smaller fraction of total cooling load show a more modest improvement using OEE instead of OAT. INTRODUCTION The International Performance Measurement and Verification Protocol (IPMVP, 2012) Option C provides procedures to determine...

  4. 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

  5. The Role of Multimodel Climate Forecasts in Improving Water and Energy Management over the Tana River Basin, Kenya

    E-Print Network [OSTI]

    Arumugam, Sankar

    - logical ensembles are used in a reservoir model to allocate water for power generation by ensuring clima. Retrospective reservoir analysis shows that inflow forecasts developed from single GCM and multiple GCMs perform the single- model inflow forecasts by reducing uncertainty and the overconfidence of individual model

  6. HIDDENARTICULATOR MARKOV MODELS: PERFORMANCE IMPROVEMENTS AND ROBUSTNESS TO NOISE

    E-Print Network [OSTI]

    Bilmes, Jeff

    ], we extended the articulatory­feature model introduced by Erler [7] by using diphone units and a new] discuss the analysis­by­synthesis approach, which attempts to estimate the parameters of the Coker [3

  7. New Methods in Tissue Engineering: Improved Models for Viral Infection

    E-Print Network [OSTI]

    Ramanan, Vyas

    New insights in the study of virus and host biology in the context of viral infection are made possible by the development of model systems that faithfully recapitulate the in vivo viral life cycle. Standard tissue culture ...

  8. USING NETWORKS OF JOURNEYS TO IMPROVE A PETROL MARKET MODEL

    E-Print Network [OSTI]

    Clark, Joanna

    producing promising results, the model was limited by the assumption that con- sumers would only buy petrol at the micro level are not tied to global level variables like oil prices); the parameters are often difficult

  9. An Improved Simple Chilled Water Cooling Coil Model

    E-Print Network [OSTI]

    Wang, Liping

    2014-01-01

    design and control of chilled water systems, Ph.D. Thesis,Dynamic modeling of chilled water cooling coils. PhD thesis,of the ratio of the water-side to the air-side conductance

  10. Systematic assessment of terrestrial biogeochemistry in coupled climate-carbon models

    E-Print Network [OSTI]

    2009-01-01

    Mirin A (2007) Combined climate and carbon-cycle effects ofcycle are a robust constraint at a large spatial scale on the combined

  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: Alternative Fuels Data Center Homesum_a_epg0_fpd_mmcf_m.xls" ,"Available from WebQuantityBonneville Power Administration would likeUniverseIMPACT EVALUATION PLAN FOR THE SITE-218 58 84(Technical Report) |Improvements

  12. Impacts of Climate Change on Biofuels Production

    SciTech Connect (OSTI)

    Melillo, Jerry M.

    2014-04-30

    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.

  13. Global well-posedness of strong solutions to a tropical climate model

    E-Print Network [OSTI]

    Li, Jinkai

    2015-01-01

    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...

  14. Improved modelling of helium and tritium production for spallation targets

    E-Print Network [OSTI]

    S. Leray; A. Boudard; J. Cugnon; J. C. David; A. Kelic-Heil; D. Mancusi; M. V. Ricciardi

    2009-12-11

    Reliable predictions of light charged particle production in spallation reactions are important to correctly assess gas production in spallation targets. In particular, the helium production yield is important for assessing damage in the window separating the accelerator vacuum from a spallation target, and tritium is a major contributor to the target radioactivity. Up to now, the models available in the MCNPX transport code, including the widely used default option Bertini-Dresner and the INCL4.2-ABLA combination of models, were not able to correctly predict light charged particle yields. The work done recently on both the intranuclear cascade model INCL4, in which cluster emission through a coalescence process has been introduced, and on the de-excitation model ABLA allows correcting these deficiencies. This paper shows that the coalescence emission plays an important role in the tritium and $^3He$ production and that the combination of the newly developed versions of the codes, INCL4.5-ABLA07, now lead to good predictions of both helium and tritium cross sections over a wide incident energy range. Comparisons with other available models are also presented.

  15. 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

  16. Improving Battery Design with Electro-Thermal Modeling

    SciTech Connect (OSTI)

    Bharathan, D.; Pesaran, A.; Vlahinos, A.; Kim, G.-H.

    2005-01-01

    Operating temperature greatly affects the performance and life of batteries in electric and hybrid vehicles. Increased attention is necessary to battery thermal management. Electrochemical models and finite element analysis tools are available for predicting the thermal performance of batteries, but each has limitations. In this study we describe an electro-thermal finite element approach that predicts the thermal performance of a cell or module with realistic geometry. To illustrate the process, we simulated the thermal performance of two generations of Panasonic prismatic nickel-metal-hydride modules used in the Toyota Prius. The model showed why the new generation of Panasonic modules had better thermal performance. Thermal images from two battery modules under constant current discharge indicate that the model predicts the experimental trend reasonably well.

  17. Climate Change and National Security

    E-Print Network [OSTI]

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

    2015-01-01

    Pew Project on National Security, Energy and Climate http://of climate change, energy security and economic stability.DoD is improving U.S. energy security and national security.

  18. 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

    2014-04-29

    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.

  19. IMPROVING EFFICIENT MARGINAL ESTIMATORS IN BIVARIATE MODELS WITH PARAMETRIC MARGINALS

    E-Print Network [OSTI]

    Schick, Anton

    AND ANTON SCHICK Abstract. Suppose we have data from a bivariate model with parametric marginals. Efficient nonparametric estimators in the presence of a constraint, see e.g. Schick and Wefelmeyer (2008) for a recent = The research of Hanxiang Peng was supported in parts by NSF Grant DMS 0940365. The research of Anton Schick

  20. 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

  1. Improving Battery Design with Electro-Thermal Modeling

    SciTech Connect (OSTI)

    Pesaran, A.; Vlahinos, A.; Bharathan, D.; Kim, G.-H.; Duong, T.

    2005-08-01

    Temperature greatly affects the performance and life of batteries in electric and hybrid vehicles under real driving conditions, so increased attention is being paid to battery thermal management. Sophisticated electrochemical models and finite element analysis tools are available for predicting the thermal performance of batteries, but each has limitations. In this study we describe an electro-thermal finite element approach that predicts the thermal performance of a cell or module with realistic geometry, material properties, loads, and boundary conditions.

  2. Electro-Thermal Modeling to Improve Battery Design: Preprint

    SciTech Connect (OSTI)

    Bharathan, D.; Pesaran, A.; Kim, G.; Vlahinos, A.

    2005-09-01

    Operating temperature greatly affects the performance and life of batteries in electric and hybrid electric vehicles (HEVs). Increased attention is necessary to battery thermal management. Electrochemical models and finite element analysis tools are available for predicting the thermal performance of batteries, but each has limitations. This study describes an electro-thermal finite element approach that predicts the thermal performance of a battery cell or module with realistic geometry.

  3. 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

    2015-01-12

    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.

  4. FUTURE CLIMATE ANALYSIS

    SciTech Connect (OSTI)

    R.M. Forester

    2000-03-14

    This Analysis/Model Report (AMR) documents an analysis that was performed to estimate climatic variables for the next 10,000 years by forecasting the timing and nature of climate change at Yucca Mountain (YM), Nevada (Figure l), the site of a potential repository for high-level radioactive waste. The future-climate estimates are based on an analysis of past-climate data from analog meteorological stations, and this AMR provides the rationale for the selection of these analog stations. The stations selected provide an upper and a lower climate bound for each future climate, and the data from those sites will provide input to the infiltration model (USGS 2000) and for the total system performance assessment for the Site Recommendation (TSPA-SR) at YM. Forecasting long-term future climates, especially for the next 10,000 years, is highly speculative and rarely attempted. A very limited literature exists concerning the subject, largely from the British radioactive waste disposal effort. The discussion presented here is one method, among many, of establishing upper and lower bounds for future climate estimates. The method used here involves selecting a particular past climate from many past climates, as an analog for future climate. Other studies might develop a different rationale or select other past climates resulting in a different future climate analog.

  5. Simple Tests of Simple Climate

    E-Print Network [OSTI]

    Withers, Paul

    Simple Tests of Simple Climate Models on More Than One Planet Paul Withers and Ralph Lorenz Spring simple climate models? * Focus on variation with latitude of annually averaged temperatures * Surface * Seasonal effects on Earth * Conclusions #12;Complicated Climate Models * General Circulation Models (GCMs

  6. Cirrus clouds in a global climate model with a statistical cirrus cloud scheme

    SciTech Connect (OSTI)

    Wang, Minghuai; Penner, Joyce E.

    2010-06-21

    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.

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

    SciTech Connect (OSTI)

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

    2013-01-01

    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.

  8. Improvements to building energy usage modeling during early design stages and retrofits

    E-Print Network [OSTI]

    Mandelbaum, Andrew (Andrew Joseph)

    2014-01-01

    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 ...

  9. Reverse supply chain forecasting and decision modeling for improved inventory management

    E-Print Network [OSTI]

    Petersen, Brian J. (Brian Jude)

    2013-01-01

    This thesis details research performed during a six-month engagement with Verizon Wireless (VzW) in the latter half of 2012. The key outcomes are a forecasting model and decision-support framework to improve management of ...

  10. 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

  11. Dissemination of Climate Model Output to the Public and Commercial Sector

    SciTech Connect (OSTI)

    Robert Stockwell, PhD

    2010-09-23

    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).

  12. Climate Science and Climate Economics

    E-Print Network [OSTI]

    Fisher, Anthony

    2014-01-01

    the World Bank by the Potsdam Institute for Climate ImpactResearch and Climate Analytics.of carbon under non-linear climate response. ESRI working

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

    SciTech Connect (OSTI)

    Baechler, M C; Love, P M

    2005-09-01

    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.

  14. A framework for interpreting climate model outputs Nadja A. Leith and Richard E. Chandler

    E-Print Network [OSTI]

    Guillas, Serge

    , the Intergovernmental Panel on Climate Change (IPCC) recently asserted that "the observed pattern of tropospheric warming and stratospheric cooling is very likely due to the influence of anthropogenic forcing" (Hegerl et

  15. Coastal communities and climate change : a dynamic model of risk perception, storms, and adaptation

    E-Print Network [OSTI]

    Franck, Travis Read

    2009-01-01

    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 ...

  16. Coupled Model Intercomparison Project 5 (CMIP5) simulations of climate following volcanic eruptions

    E-Print Network [OSTI]

    Robock, Alan

    to capture the NH dynamical response following eruptions. They do not sufficiently simulate the observed post] For a volcano to have a significant long-term impact on the climate it must inject a sufficient amount of sulfur

  17. Community level consequences of adaptive management through Climate Matching: oak galls as a model system 

    E-Print Network [OSTI]

    Sinclair, Frazer Hamilton

    2012-11-30

    In the present century, ecosystems across the globe will be subject to profound changes in climate. Forests are expected to be particularly sensitive to such change as the long life span of trees limits the potential for ...

  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.

    1992-06-01

    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.

    1992-06-01

    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. Technology Solutions Case Study: Improving Comfort in Hot-Humid Climates with a Whole-House Dehumidifier

    SciTech Connect (OSTI)

    2013-11-01

    In order to quantify the performance of a combined whole-house dehumidifier (WHD) AC system, researchers from the Consortium of Advanced Residential Buildings (CARB) team 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°-80°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.

  1. 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

    2013-07-22

    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.

  2. 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 ...

  3. The physical science behind climate change

    SciTech Connect (OSTI)

    Collins, William; Collins, William; Colman, Robert; Haywood, James; Manning, Martin R.; Mote, Philip

    2007-07-01

    For a scientist studying climate change, 'eureka' moments are unusually rare. Instead progress is generally made by a painstaking piecing together of evidence from every new temperature measurement, satellite sounding or climate-model experiment. Data get checked and rechecked, ideas tested over and over again. Do the observations fit the predicted changes? Could there be some alternative explanation? Good climate scientists, like all good scientists, want to ensure that the highest standards of proof apply to everything they discover. And the evidence of change has mounted as climate records have grown longer, as our understanding of the climate system has improved and as climate models have become ever more reliable. Over the past 20 years, evidence that humans are affecting the climate has accumulated inexorably, and with it has come ever greater certainty across the scientific community in the reality of recent climate change and the potential for much greater change in the future. This increased certainty is starkly reflected in the latest report of the Intergovernmental Panel on Climate Change (IPCC), the fourth in a series of assessments of the state of knowledge on the topic, written and reviewed by hundreds of scientists worldwide. The panel released a condensed version of the first part of the report, on the physical science basis of climate change, in February. Called the 'Summary for Policymakers,' it delivered to policymakers and ordinary people alike an unambiguous message: scientists are more confident than ever that humans have interfered with the climate and that further human-induced climate change is on the way. Although the report finds that some of these further changes are now inevitable, its analysis also confirms that the future, particularly in the longer term, remains largely in our hands--the magnitude of expected change depends on what humans choose to do about greenhouse gas emissions. The physical science assessment focuses on four topics: drivers of climate change, changes observed in the climate system, understanding cause-and-effect relationships, and projection of future changes. Important advances in research into all these areas have occurred since the IPCC assessment in 2001. In the pages that follow, we lay out the key findings that document the extent of change and that point to the unavoidable conclusion that human activity is driving it.

  4. 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

  5. 2 CONCEPT OF MODEL BASED TAMPERING FOR 3 IMPROVING PROCESS PERFORMANCE

    E-Print Network [OSTI]

    Bukkapatnam, Satish T.S.

    1 2 CONCEPT OF MODEL BASED TAMPERING FOR 3 IMPROVING PROCESS PERFORMANCE: 4 AN ILLUSTRATIVE 14 This paper presents the concept of a methodology called Model Based 15 Tampering (MBT based tampering (MBT), which is conceptualized in this paper, will 38 become necessary in order to meet

  6. Development of an Improved Model for Piezo-Electric Driven Ink Jets

    E-Print Network [OSTI]

    Recktenwald, Gerald

    Development of an Improved Model for Piezo-Electric Driven Ink Jets Sharon S. Berger Xerox dynamic behavior of phase-change ink jets, including the individual jets in a print head. A typical model of an ink jet is based upon lumped-parameter (no spatial variation) assumptions. While quite accurately

  7. CLIMATE RESEARCH Vol. 61: 7591, 2014

    E-Print Network [OSTI]

    sample of climate projections, including 1 regional climate model (RCM) following 3 emission scenarios (A. KEY WORDS: Heat waves · Regional climate models · Reference historical time series · Sources) with the ECHAM3 model and Meehl & Tebaldi (2004) with the Parallel Climate Model. More recently, Chauvin & Denvil

  8. Uncertainty analysis of an aviation climate model and an aircraft price model for assessment of environmental effects

    E-Print Network [OSTI]

    Jun, Mina

    2007-01-01

    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 ...

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

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

    Hartin, Corinne A.; Patel, Pralit L.; Schwarber, Adria; Link, Robert P.; Bond-Lamberty, Benjamin

    2015-04-01

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

  10. 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

    2015-01-01

    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.

  11. Energy Department Announces Funding to Improve Grid Resiliency...

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

    Energy Department Announces Funding to Improve Grid Resiliency and Climate Preparedness Energy Department Announces Funding to Improve Grid Resiliency and Climate Preparedness...

  12. An assessment of possible climate change in the Australian region based on intercomparison of general circulation modeling results

    SciTech Connect (OSTI)

    Whetton, P.H.; Pittock, A.B.; Haylock, M.R. ); Rayner, P.J. )

    1994-03-01

    To assist in estimating likely future climate change in the Australian region, the authors examine the results of four different general circulation modeling experiments run to assess the equilibrium impact of doubling greenhouse gases. The results examined were the most recent available at the time of study from various research centers in North America and Europe, as well as those of the Commonwealth Scientific and Industrial Research Organisation (CSIRO). The approach used is, first, to assess the quality of the control (1 x CO[sub 2]) simulations from each of the models of mean sea level (MSL) pressure and precipitation in the Australian region by comparing these with the corresponding observed patterns; and, second, to then analyze the 2 x CO[sub 2] results of only those model experiments with the best control simulations. Of the models examined two are chosen on the basis of their simulation of current climate in the region: the CSIRO four-level model (CSIRO4) and the United Kingdom Meteorological Office (UKMO) model. For conditions of equivalent doubling of CO[sub 2], both models show substantial increases in surface air temperature of around 4[degrees]-6[degrees] inland and 2[degrees]-4[degrees]C in coastal regions. Both models show decreased MSL pressure over the Australian continent and increases in rainfall over northern, central, and eastern Australia, particularly in the summer half of the year. The CSIRO4 model, but not the UKMO model, also shows increased pressure to the south of the continent and decreased winter rainfall in southwest and southern Australia. Generally, field significance tests show the pattern and magnitude of the changes to be significant of CSIRO4 (for which the necessary monthly simulated data were available). 42 refs., 20 figs., 5 tabs.

  13. Information theory and climate prediction 

    E-Print Network [OSTI]

    Leung, Lai-yung

    1988-01-01

    obtained from more sophisticated model. It is amazing that the complicated climate system can be described by such simple energy balance concept. The assumption of homogeneous noise over the sphere is for convenient of calculation and interpretation... in climate prediction study will be demonstrated by using a simple stochastic climate model. Its interpretations and usefulness especially when generalized to other climate models will be discussed and suggestions for using these concepts of information...

  14. Future Climate Analysis

    SciTech Connect (OSTI)

    James Houseworth

    2001-10-12

    This Analysis/Model Report (AMR) documents an analysis that was performed to estimate climatic variables for the next 10,000 years by forecasting the timing and nature of climate change at Yucca Mountain (YM), Nevada (Figure 1), the site of a potential repository for high-level radioactive waste. The future-climate estimates are based on an analysis of past-climate data from analog meteorological stations, and this AMR provides the rationale for the selection of these analog stations. The stations selected provide an upper and a lower climate bound for each future climate, and the data from those sites will provide input to the infiltration model (USGS 2000) and for the total system performance assessment for the Site Recommendation (TSPA-SR) at YM. Forecasting long-term future climates, especially for the next 10,000 years, is highly speculative and rarely attempted. A very limited literature exists concerning the subject, largely from the British radioactive waste disposal effort. The discussion presented here is one method, among many, of establishing upper and lower bounds for future climate estimates. The method used here involves selecting a particular past climate from many past climates, as an analog for future climate. Other studies might develop a different rationale or select other past climates resulting in a different future climate analog. Revision 00 of this AMR was prepared in accordance with the ''Work Direction and Planning Document for Future Climate Analysis'' (Peterman 1999) under Interagency Agreement DE-AI08-97NV12033 with the U.S. Department of Energy (DOE). The planning document for the technical scope, content, and management of ICN 01 of this AMR is the ''Technical Work Plan for Unsaturated Zone (UZ) Flow and Transport Process Model Report'' (BSC 2001a). The scope for the TBV resolution actions in this ICN is described in the ''Technical Work Plan for: Integrated Management of Technical Product Input Department''. (BSC 2001b, Addendum B, Section 4.1).

  15. Application of an online-coupled regional climate model, WRF-CAM5, over East Asia for examination of ice nucleation schemes: Part I. Comprehensive model evaluation and trend analysis for 2006 and 2011

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

    Chen, Ying; Zhang, Yang; Fan, Jiwen; Leung, Lai -Yung; Zhang, Qiang; He, Kebin

    2015-08-18

    Online-coupled climate and chemistry models are necessary to realistically represent the interactions between climate variables and chemical species and accurately simulate aerosol direct and indirect effects on cloud, precipitation, and radiation. In this Part I of a two-part paper, simulations from the Weather Research and Forecasting model coupled with the physics package of Community Atmosphere Model (WRF-CAM5) are conducted with the default heterogeneous ice nucleation parameterization over East Asia for two full years: 2006 and 2011. A comprehensive model evaluation is performed using satellite and surface observations. The model shows an overall acceptable performance for major meteorological variables at themore »surface and in the boundary layer, as well as column variables (e.g., precipitation, cloud fraction, precipitating water vapor, downward longwave and shortwave radiation). Moderate to large biases exist for cloud condensation nuclei over oceanic areas, cloud variables (e.g., cloud droplet number concentration, cloud liquid and ice water paths, cloud optical depth, longwave and shortwave cloud forcing). These biases indicate a need to improve the model treatments for cloud processes, especially cloud droplets and ice nucleation, as well as to reduce uncertainty in the satellite retrievals. The model simulates well the column abundances of chemical species except for column SO2 but relatively poor for surface concentrations of several species such as CO, NO2, SO2, PM2.5, and PM10. Several reasons could contribute to the underestimation of major chemical species in East Asia including underestimations of anthropogenic emissions and natural dust emissions, uncertainties in the spatial and vertical distributions of the anthropogenic emissions, as well as biases in meteorological, radiative, and cloud predictions. Despite moderate to large biases in the chemical predictions, the model performance is generally consistent with or even better than that reported for East Asia with only a few exceptions. The model generally reproduces the observed seasonal variations and the difference between 2006 and 2011 for most variables or chemical species. Overall, these results demonstrate promising skills of WRF-CAM5 for long-term simulations at a regional scale and suggest several areas of potential improvements.« less

  16. 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

  17. Improved Crosstalk Modeling for Noise Constrained Interconnect Optimization Jason Cong, David Zhigang Pan and Prasanna V. Srinivas

    E-Print Network [OSTI]

    Pan, David Z.

    Improved Crosstalk Modeling for Noise Constrained Interconnect Optimization Jason Cong, David This paper presents a much improved, highly accurate yet effi- cient crosstalk noise model, the 2-˘ model, and applies it to noise- constrained interconnect optimizations. Compared with previous crosstalk noise models

  18. A MODELING APPROACH TO ESTIMATING SNOW COVER DEPLETION AND SOIL MOISTURE RECHARGE IN A SEMI-ARID CLIMATE AT TWO NASA CLPX

    E-Print Network [OSTI]

    Anderson, Charles W.

    THESIS A MODELING APPROACH TO ESTIMATING SNOW COVER DEPLETION AND SOIL MOISTURE RECHARGE IN A SEMI A MODELING APPROACH TO ESTIMATING SNOW COVER DEPLETION AND SOIL MOISTURE RECHARGE IN A SEMI-ARID CLIMATE ________________________________________ Department Head #12;iii ABSTRACT A MODELING APPROACH TO ESTIMATING SNOW COVER DEPLETION AND SOIL MOISTURE

  19. Climate change under aggressive mitigation: the ENSEMBLES multi-model experiment

    E-Print Network [OSTI]

    Dufresne, Jean-Louis

    -10, 12165 Berlin, Germany H. Huebener Hessian Agency for the Environment and Geology, Rheingaustraße 186, Italy W. May Á S. Yang Danish Climate Centre, Danish Meteorological Institute, Lyngbyvej 100, 2100.4) with reduced fossil fuel use for energy production aimed at stabilizing global warming below 2 K, is studied

  20. Pluralistic Modelling Approaches to Simulating Climate-Land Change Interactions in East Africa

    E-Print Network [OSTI]

    . Alexandridis4 1 Department of Forestry and Natural Resources, Purdue University, West Lafayette, Indiana 47906 food production systems, crop prices and market dynamics, human behavioural factors such as risk with atmospheric trends such as greenhouse gas concentrations, to loop back to regional and global climate change

  1. OFFICE OF BIOLOGICAL AND ENVIRONMENTAL RESEARCH Climate and Earth System Modeling

    E-Print Network [OSTI]

    and their interactions with climate under conditions of increasing atmospheric carbon dioxide (CO2 ), we need to develop-analyses of terrestrial ecosystem manipulations of carbon dioxide, warming, nutrients, soil moisture, and tree cover benchmarking system that leverages a growing collection of laboratory, field, and remote sensing data

  2. MODELING LAND SURFACE PROCESSES IN SHORT-TERM WEATHER AND CLIMATE STUDIES

    E-Print Network [OSTI]

    Yang, Zong-Liang

    , glaciers, inland water, mountains, animals, human beings, their shelters, and much more. Land surface@mail.utexas.edu Website: www.geo.utexas.edu/climate (Manuscript received 31 January 2003) Land exchanges momentum, energy, water, aerosols, carbon dioxide and other trace gases with its overlying atmosphere. The land surface

  3. Modeling Climate Change Policies in Canada and the U.S.: An Update 

    E-Print Network [OSTI]

    Roop, J. M.; Tubbs, W. J.

    2009-01-01

    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...

  4. Climate change and human health: Spatial modeling of water availability, malnutrition, and livelihoods in Mali, Africa

    E-Print Network [OSTI]

    Lopez-Carr, David

    , and livelihoods in Mali, Africa Marta M. Jankowskaa,*,1 , David Lopez-Carrb,1 , Chris Funkc , Gregory J. Husakd Malnutrition Mali-Africa Livelihoods a b s t r a c t This study develops a novel approach for projecting climate trends in the Sahel in relation to shifting livelihood zones and health outcomes. Focusing on Mali

  5. Identification of Linear Climate Models from the CMIP3 Multimodel Ensemble

    E-Print Network [OSTI]

    Phipps, Steven J.

    a superimposed impulse in solar radiative forcing for the purposes of system identification, we identify 12 to geoengineering of the climate based on solar radiation management (SRM). 1. INTRODUCTION In response to the risks greenhouse gases (GHGs) by restricting anthro- pogenic emissions. The limited effectiveness to date

  6. The Program for Climate Model Diagnosis and Intercomparison (PCMDI) Software Development: Applications, Infrastructure, and Middleware/Networks

    SciTech Connect (OSTI)

    Williams, Dean N.

    2011-06-30

    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.

  7. 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

    2013-12-16

    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.

  8. 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

  9. IN THIS ISSUE Regional Climate Change..............1

    E-Print Network [OSTI]

    Hamann, Andreas

    IN THIS ISSUE · Regional Climate Change..............1 · From the Executive Director...........2 release of new climate change scenarios from the Canadian Regional Climate Model (CRCM) heralds of the fundamental questions remaining with respect to understanding climate change and even climate variability. And

  10. 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

  11. An improved constitutive model for cyclic material behavior in creep range

    SciTech Connect (OSTI)

    Kussmaul, K.; Maile, K.; Xu, H.; Sheng, S.

    1995-12-31

    Structural components operated at elevated temperatures are often subjected to complex loading histories combining cyclic plasticity and creep. The design and life prediction of these components require accurate description of the non-linear stress-strain response under the cyclic loading. In the paper the results of an ongoing R&D-programme performed at MPA Stuttgart is presented. The objective of this work is to model the cyclic material behavior in the temperature range where time-dependent plasticity is dominant. A series of tests from room temperature UP to 550{degrees}C have been carried out to determine the cyclic material behavior of the turbine steels 1 CrMoV, 2CrMoVNiW and the bolt material Nimonic 80A. On the basis of the acquired experimental data the commonly used constitutive model developed by Chaboche et al. is evaluated and improved. The following aspects are considered in the improved model: Influence of the kinematic back stress on the viscoplastic material behavior Description of the temperature dependent and time-dependent viscosity Method of determination of the material constants used in the model: The comparison of these analytical results and the experimental data shows that the improved model is suitable to describe the cyclic material behavior under uniaxial loading. To verify the developed model for multiaxial loading on the basis of the test data, an implementation of the constitutive model in a finite element code will be performed.

  12. 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.

    2012-04-30

    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.

  13. Improved blade profile loss and deviation angle models for advanced transonic compressor bladings. Part 1: A model for subsonic flow

    SciTech Connect (OSTI)

    Koenig, W.M.; Hennecke, D.K.; Fottner, L.

    1996-01-01

    New blading concepts as used in modern transonic axial-flow compressors require improved loss and deviation angle correlations. The new model presented in this paper incorporates several elements and treats blade-row flows having subsonic and supersonic inlet conditions separately. In the first part of this paper two proved and well-established profile loss correlations for subsonic flows are extended to quasi-two-dimensional conditions and to custom-tailored blade designs. Instead of a deviation angle correlation, a simple method based on singularities is utilized. The comparison between the new model and a recently published model demonstrates the improved accuracy in prediction of cascade performance achieved by the new model.

  14. CLIMATE CHANGE AND SEA LEVEL RISE SCENARIOS FOR CALIFORNIA

    E-Print Network [OSTI]

    CLIMATE CHANGE AND SEA LEVEL RISE SCENARIOS FOR CALIFORNIA VULNERABILITY AND ADAPTATION ASSESSMENT A White Paper from the California Energy Commission's California Climate Change Center for Climate Model Diagnosis and Intercomparison and the World Climate Research Program (WCRP) Working Group

  15. Simulated diurnal rainfall physics in a multi-scale global climate model with embedded explicit convection

    E-Print Network [OSTI]

    Pritchard, Michael Stephen

    2011-01-01

    their Community Earth System Model (Richard Neale, personaldevelopment of Earth system models capable of reproducing

  16. Effect of Scale on the Modeling of Hydrologic Effects of Climate Change on the Niger River Basin

    E-Print Network [OSTI]

    Mountziaris, T. J.

    infrastructural investments for irrigation and hydroelectricity development. Climate change is a potential threat

  17. CLIMATE RISK AND CLIMATE CHANGE

    E-Print Network [OSTI]

    Smerdon, Jason E.

    CLIMATE RISK AND CLIMATE CHANGE Scenarios of what the climate will be like 50 to 100 years from now associated with climate change demand these efforts continue. However, the long time horizons have led many decision makers to regard climate change as a problem of the distant future. But is it? I n many regions

  18. An improved Reynolds-equation model for gas damping of microbeam motion.

    SciTech Connect (OSTI)

    Gallis, Michail A.; Torczynski, John Robert

    2003-09-01

    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.

  19. 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)

    2008-05-01

    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.

  20. Wake models are used to improve predictions of Annual Energy Production (AEP) of wind farms.

    E-Print Network [OSTI]

    Daraio, Chiara

    measurements in the ETHZ facility compare well with measurements at the Horns Rev offshore wind farm·Wake models are used to improve predictions of Annual Energy Production (AEP) of wind farms. ·Wake and wind turbine wakes in large windfarms offshore, Wind Energy 12, pp. 431-444, 2009. [2] L.P. Chamorro

  1. Adaptive Software Testing in the Context of an Improved Controlled Markov Chain Model

    E-Print Network [OSTI]

    Kundu, Sukhamay

    Adaptive Software Testing in the Context of an Improved Controlled Markov Chain Model Hai Hu, Chang@buaa.edu.cn Abstract Adaptive software testing is the counterpart of adaptive control in software testing. It means that software testing strategy should be adjusted on- line by using the testing data collected during software

  2. 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

  3. On Closed Task of Chinese Word Segmentation: An Improved CRF Model Coupled with Character Clustering and

    E-Print Network [OSTI]

    Chu, Hao-hua

    On Closed Task of Chinese Word Segmentation: An Improved CRF Model Coupled with Character,yabt,clsung,hongjie,hsu}@iis.sinica.edu.tw Abstract This paper addresses two major prob- lems in closed task of Chinese word segmentation (CWS): tagging sentences interspersed with non-Chinese words, and long named entity (NE) identifica- tion

  4. Project Title Improved Emission Models for Project Evaluation (MOVES-Matrix) University Georgia Institute of Technology

    E-Print Network [OSTI]

    California at Davis, University of

    Project Title Improved Emission Models for Project Evaluation (MOVES-Matrix) University Georgia or organization) DOT - $92,292.15 Total Project Cost $92,292.15 Agency ID or Contract Number DTRT13-G-UTC29 Start and End Dates November 1, 2013 ­ June 30, 2015 Brief Description of Research Project Local governments

  5. 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

  6. A Supply-Demand Model Based Scalable Energy Management System for Improved Energy

    E-Print Network [OSTI]

    Bhunia, Swarup

    A Supply-Demand Model Based Scalable Energy Management System for Improved Energy Utilization: sxn124@case.edu Abstract-Harvesting energy from the environment can play an important role in reducing the dependency of an electronic system to primary energy sources (i.e. AC power or battery). For reliable

  7. Three-body interactions improve the prediction of rate and mechanism in protein folding models

    E-Print Network [OSTI]

    Plotkin, Steven S.

    Three-body interactions improve the prediction of rate and mechanism in protein folding models M. R-body interactions on rate and mechanism in protein folding by using the results of molecular dynamics simulations that stabilize protein structures and govern protein folding mechanisms is a fundamental problem in molecular

  8. he Impact of Primary Marine Aerosol on Atmospheric Chemistry, Radiation and Climate: A CCSM Model Development Study

    SciTech Connect (OSTI)

    Keene, William C.; Long, Michael S.

    2013-05-20

    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.

  9. Systematic assessment of terrestrial biogeochemistry in coupled climate-carbon models

    E-Print Network [OSTI]

    2009-01-01

    coming from earth system models performing simulations forecological and earth system observations. Model results fromEarth System Grid. Keywords: ameriflux, atmospheric tracer transport model

  10. 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.

    2010-11-01

    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.

  11. Data Quality Assessment and Control for the ARM Climate Research Facility

    SciTech Connect (OSTI)

    Peppler, R

    2012-06-26

    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.

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

    SciTech Connect (OSTI)

    2005-08-01

    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.

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

    SciTech Connect (OSTI)

    2005-09-01

    This 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.

  14. 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.

    2008-02-12

    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.

  15. 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.

    2013-09-30

    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.

  16. Use of North American and European air quality networks to evaluate global chemistry-climate modeling of surface ozone

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

    Schnell, J. L.; Prather, M. J.; Josse, B.; Naik, V.; Horowitz, L. W.; Cameron-Smith, P.; Bergmann, D.; Zeng, G.; Plummer, D. A.; Sudo, K.; et al

    2015-04-16

    We test the current generation of global chemistry-climate models in their ability to simulate observed, present-day surface ozone. Models are evaluated against hourly surface ozone from 4217 stations in North America and Europe that are averaged over 1° × 1° grid cells, allowing commensurate model-measurement comparison. Models are generally biased high during all hours of the day and in all regions. Most models simulate the shape of regional summertime diurnal and annual cycles well, correctly matching the timing of hourly (~ 15:00) and monthly (mid-June) peak surface ozone abundance. The amplitude of these cycles is less successfully matched. The observedmore »summertime diurnal range (~ 25 ppb) is underestimated in all regions by about 7 ppb, and the observed seasonal range (~ 21 ppb) is underestimated by about 5 ppb except in the most polluted regions where it is overestimated by about 5 ppb. The models generally match the pattern of the observed summertime ozone enhancement, but they overestimate its magnitude in most regions. Most models capture the observed distribution of extreme episode sizes, correctly showing that about 80% of individual extreme events occur in large-scale, multi-day episodes of more than 100 grid cells. The observed linear relationship showing increases in ozone by up to 6 ppb for larger-sized episodes is also matched.« less

  17. Multi-model Mean Nitrogen and Sulfur Deposition from the Atmospheric Chemistry and Climate Model Intercomparison Project (ACCMIP): Evaluation of Historical and Projected Future Changes

    SciTech Connect (OSTI)

    Lamarque, Jean-Francois; Dentener, Frank; McConnell, J.R.; Ro, C-U; Shaw, Mark; Vet, Robert; Bergmann, D.; Cameron-Smith, Philip; Dalsoren, S.; Doherty, R.; Faluvegi, G.; Ghan, Steven J.; Josse, B.; Lee, Y. H.; MacKenzie, I. A.; Plummer, David; Shindell, Drew; Skeie, R. B.; Stevenson, D. S.; Strode, S.; Zeng, G.; Curran, M.; Dahl-Jensen, D.; Das, S.; Fritzsche, D.; Nolan, M.

    2013-08-20

    We present multi-model global datasets of nitrogen and sulfate deposition covering time periods from 1850 to 2100, calculated within the Atmospheric Chemistry and Climate Model Intercomparison Project (ACCMIP). The computed deposition fluxes are compared to surface wet deposition and ice-core measurements. We use a new dataset of wet deposition for 2000-2002 based on critical assessment of the quality of existing regional network data. We show that for present-day (year 2000 ACCMIP time-slice), the ACCMIP results perform similarly to previously published multi-model assessments. The analysis of changes between 1980 and 2000 indicates significant differences between model and measurements over the United States, but less so over Europe. This difference points towards misrepresentation of 1980 NH3 emissions over North America. Based on ice-core records, the 1850 deposition fluxes agree well with Greenland ice cores but the change between 1850 and 2000 seems to be overestimated in the Northern Hemisphere for both nitrogen and sulfur species. Using the Representative Concentration Pathways to define the projected climate and atmospheric chemistry related emissions and concentrations, we find large regional nitrogen deposition increases in 2100 in Latin America, Africa and parts of Asia under some of the scenarios considered. Increases in South Asia are especially large, and are seen in all scenarios, with 2100 values more than double 2000 in some scenarios and reaching >1300 mgN/m2/yr averaged over regional to continental scale regions in RCP 2.6 and 8.5, ~30-50% larger than the values in any region currently (2000). Despite known issues, the new ACCMIP deposition dataset provides novel, consistent and evaluated global gridded deposition fields for use in a wide range of climate and ecological studies.

  18. Effects of Market Approaches to Green Technologies for the Poor: The Case of Improved Cookstoves

    E-Print Network [OSTI]

    Booker, Kayje Merrea

    2011-01-01

    quot;climate-poverty-energy" technologies (Casillas &a single climate-poverty-energy technology, improved biomass77 important technology for both climate change mitigation

  19. 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

    2015-01-01

    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...

  20. 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)

    2003-07-01

    A procedure for iterative model-building, statistical density modification and refinement at moderate resolution (up to about 2.8 Ĺ) is described. An iterative process for improving the completeness and quality of atomic models automatically built at moderate resolution (up to about 2.8 Ĺ) 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 Ĺ, 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 Ĺ) was rebuilt using only structure-factor amplitude information at varying resolutions from 2.0 to 3.0 Ĺ. Rebuilding was effective at resolutions up to about 2.5 Ĺ. 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 Ĺ. The algorithm is useful for building preliminary models of macromolecules suitable for an experienced crystallographer to extend, correct and fully refine.