Sample records for modeling complex arctic

  1. Evaluation of Arctic sea ice thickness simulated by Arctic Ocean Model Intercomparison Project models

    E-Print Network [OSTI]

    Zhang, Jinlun

    of fast ice formation and growth. Instead, the modeled fast ice is replaced with pack ice which driftsEvaluation of Arctic sea ice thickness simulated by Arctic Ocean Model Intercomparison Project with estimates of sea ice thickness derived from pan-Arctic satellite freeboard measurements (2004

  2. Network Modeling of Arctic Melt Ponds Meenakshi Barjatiaa

    E-Print Network [OSTI]

    Golden, Kenneth M.

    . In late spring and summer, the albedo of the ice pack is determined primarily by melt ponds that form­albedo feedback [7], and has played a significant role in the decline of the summer Arctic ice pack [8]. Sea ice precipitous losses of summer Arctic sea ice have outpaced the pro- jections of most climate models. Efforts

  3. Distant origins of Arctic black carbon: A Goddard Institute for Space Studies ModelE experiment

    E-Print Network [OSTI]

    [Wallace and Thompson, 2002]. The Arctic climate is especially sensitive to changes in the hydrological005296. 1. Introduction [2] The Arctic is a particularly sensitive region to global climate change. Observations and models indicate that as the climate warms, the Arctic warms most and fastest [e.g., Manabe et

  4. 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

  5. arXiv:1408.2487v2[physics.ao-ph]22Aug2014 Ising model for melt ponds on Arctic sea ice

    E-Print Network [OSTI]

    Golden, Kenneth M.

    arXiv:1408.2487v2[physics.ao-ph]22Aug2014 Ising model for melt ponds on Arctic sea ice Yi-Ping Ma,1, USA The albedo of melting Arctic sea ice, a key parameter in climate modeling, is determined by pools of water on the ice surface. Recent observations show an onset of pond complexity at a critical area

  6. A Sensitivity Study on Modeling Black Carbon in Snow and its Radiative Forcing over the Arctic and Northern China

    SciTech Connect (OSTI)

    Qian, Yun; Wang, Hailong; Zhang, Rudong; Flanner, M. G.; Rasch, Philip J.

    2014-06-02T23:59:59.000Z

    Black carbon in snow (BCS) simulated in the Community Atmosphere Model (CAM5) is evaluated against measurements over Northern China and the Arctic, and its sensitivity to atmospheric deposition and two parameters that affect post-depositional enrichment is explored. The BCS concentration is overestimated (underestimated) by a factor of two in Northern China (Arctic) in the default model, but agreement with observations is good over both regions in the simulation with improvements in BC transport and deposition. Sensitivity studies indicate that uncertainty in the melt-water scavenging efficiency (MSE) parameter substantially affects BCS and its radiative forcing (by a factor of 2-7) in the Arctic through post-depositional enrichment. The MSE parameter has a relatively small effect on the magnitude of BCS seasonal cycle but can alter its phase in Northern China. The impact of the snow aging scaling factor (SAF) on BCS, partly through the post-depositional enrichment effect, shows more complex latitudinal and seasonal dependence. Similar to MSE, SAF affects more significantly the magnitude (phase) of BCS season cycle over the Arctic (Northern China). While uncertainty associated with the representation of BC transport and deposition processes in CAM5 is more important than that associated with the two snow model parameters in Northern China, the two uncertainties have comparable effect in the Arctic.

  7. Mesoscale Modeling During Mixed-Phase Arctic Cloud Experiment

    SciTech Connect (OSTI)

    Avramov, A.; Harringston, J.Y.; Verlinde, J.

    2005-03-18T23:59:59.000Z

    Mixed-phase arctic stratus clouds are the predominant cloud type in the Arctic (Curry et al. 2000) and through various feedback mechanisms exert a strong influence on the Arctic climate. Perhaps one of the most intriguing of their features is that they tend to have liquid tops that precipitate ice. Despite the fact that this situation is colloidally unstable, these cloud systems are quite long lived - from a few days to over a couple of weeks. It has been hypothesized that mixed-phase clouds are maintained through a balance between liquid water condensation resulting from the cloud-top radiative cooling and ice removal by precipitation (Pinto 1998; Harrington et al. 1999). In their modeling study Harrington et al. (1999) found that the maintenance of this balance depends strongly on the ambient concentration of ice forming nucleus (IFN). In a follow-up study, Jiang et al. (2002), using only 30% of IFN concentration predicted by Meyers et al. (1992) IFN parameterization were able to obtain results similar to the observations reported by Pinto (1998). The IFN concentration measurements collected during the Mixed-Phase Arctic Cloud Experiment (M-PACE), conducted in October 2004 over the North Slope of Alaska and the Beaufort Sea (Verlinde et al. 2005), also showed much lower values then those predicted (Prenne, pers. comm.) by currently accepted ice nucleation parameterizations (e.g. Meyers et al. 1992). The goal of this study is to use the extensive IFN data taken during M-PACE to examine what effects low IFN concentrations have on mesoscale cloud structure and coastal dynamics.

  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)

    Lettenmaier, Dennis P

    2013-04-08T23:59:59.000Z

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

  9. An energy-diagnostics intercomparison of coupled ice-ocean Arctic models

    E-Print Network [OSTI]

    Zhang, Jinlun

    An energy-diagnostics intercomparison of coupled ice-ocean Arctic models Petteri Uotila a,*, David. Understanding the Arctic Ocean energy balance is important because it can strengthen our understanding for Atmosphere-Ocean Science, Courant Institute of Mathematical Sciences, New York University, NYU, 200 Water

  10. 2012 Changing Arctic Ocean 506E/497E -Lecture 17 -Woodgate Global models in the Arctic

    E-Print Network [OSTI]

    Washington at Seattle, University of

    ;2 2012 Changing Arctic Ocean 506E/497E - Lecture 17 - Woodgate Deep waters of the Atlantic from http://sam://iodp.tamu.edu/publications/PR/303PR/images/Fig01.jpg Dickson et al, refs Denmark Strait ~ 650m deep Iceland Scotland Ridge ~ 400

  11. Development, sensitivity analysis, and uncertainty quantification of high-fidelity arctic sea ice models.

    SciTech Connect (OSTI)

    Peterson, Kara J.; Bochev, Pavel Blagoveston; Paskaleva, Biliana S.

    2010-09-01T23:59:59.000Z

    Arctic sea ice is an important component of the global climate system and due to feedback effects the Arctic ice cover is changing rapidly. Predictive mathematical models are of paramount importance for accurate estimates of the future ice trajectory. However, the sea ice components of Global Climate Models (GCMs) vary significantly in their prediction of the future state of Arctic sea ice and have generally underestimated the rate of decline in minimum sea ice extent seen over the past thirty years. One of the contributing factors to this variability is the sensitivity of the sea ice to model physical parameters. A new sea ice model that has the potential to improve sea ice predictions incorporates an anisotropic elastic-decohesive rheology and dynamics solved using the material-point method (MPM), which combines Lagrangian particles for advection with a background grid for gradient computations. We evaluate the variability of the Los Alamos National Laboratory CICE code and the MPM sea ice code for a single year simulation of the Arctic basin using consistent ocean and atmospheric forcing. Sensitivities of ice volume, ice area, ice extent, root mean square (RMS) ice speed, central Arctic ice thickness, and central Arctic ice speed with respect to ten different dynamic and thermodynamic parameters are evaluated both individually and in combination using the Design Analysis Kit for Optimization and Terascale Applications (DAKOTA). We find similar responses for the two codes and some interesting seasonal variability in the strength of the parameters on the solution.

  12. A multi-model assessment of pollution transport to the Arctic

    SciTech Connect (OSTI)

    Shindell, D T; Chin, M; Dentener, F; Doherty, R M; Faluvegi, G; Fiore, A M; Hess, P; Koch, D M; MacKenzie, I A; Sanderson, M G; Schultz, M G; Schulz, M; Stevenson, D S; Teich, H; Textor, C; Wild, O; Bergmann, D J; Bey, I; Bian, H; Cuvelier, C; Duncan, B N; Folberth, G; Horowitz, L W; Jonson, J; Kaminski, J W; Marmer, E; Park, R; Pringle, K J; Schroeder, S; Szopa, S; Takemura, T; Zeng, G; Keating, T J; Zuber, A

    2008-03-13T23:59:59.000Z

    We examine the response of Arctic gas and aerosol concentrations to perturbations in pollutant emissions from Europe, East and South Asia, and North America using results from a coordinated model intercomparison. These sensitivities to regional emissions (mixing ratio change per unit emission) vary widely across models and species. Intermodel differences are systematic, however, so that the relative importance of different regions is robust. North America contributes the most to Arctic ozone pollution. For aerosols and CO, European emissions dominate at the Arctic surface but East Asian emissions become progressively more important with altitude, and are dominant in the upper troposphere. Sensitivities show strong seasonality: surface sensitivities typically maximize during boreal winter for European and during spring for East Asian and North American emissions. Mid-tropospheric sensitivities, however, nearly always maximize during spring or summer for all regions. Deposition of black carbon (BC) onto Greenland is most sensitive to North American emissions. North America and Europe each contribute {approx}40% of total BC deposition to Greenland, with {approx}20% from East Asia. Elsewhere in the Arctic, both sensitivity and total BC deposition are dominated by European emissions. Model diversity for aerosols is especially large, resulting primarily from differences in aerosol physical and chemical processing (including removal). Comparison of modeled aerosol concentrations with observations indicates problems in the models, and perhaps, interpretation of the measurements. For gas phase pollutants such as CO and O{sub 3}, which are relatively well-simulated, the processes contributing most to uncertainties depend on the source region and altitude examined. Uncertainties in the Arctic surface CO response to emissions perturbations are dominated by emissions for East Asian sources, while uncertainties in transport, emissions, and oxidation are comparable for European and North American sources. At higher levels, model-to-model variations in transport and oxidation are most important. Differences in photochemistry appear to play the largest role in the intermodel variations in Arctic ozone sensitivity, though transport also contributes substantially in the mid-troposphere.

  13. Ventilation of the Miocene Arctic Ocean: An idealized model study Bijoy Thompson,1

    E-Print Network [OSTI]

    Nycander, Jonas

    Ventilation of the Miocene Arctic Ocean: An idealized model study Bijoy Thompson,1 Johan Nilsson,2 the early Miocene, a feature presumably related to the opening of the Fram Strait. Here, the ventilation circulation model that includes a passive age tracer. In particular, we investigate how the ventilation

  14. Modelling the impact of superimposed ice on the mass balance of an Arctic glacier under scenarios of future climate change

    E-Print Network [OSTI]

    ). A consequence of climatic warming in the high Arctic will be an increase in surface melting of glaciers and ice component of the mass accumulation of many glaciers and ice caps in thModelling the impact of superimposed ice on the mass balance of an Arctic glacier under scenarios

  15. Fundamental problems of modeling the dynamics of internal gravity waves with applications to the Arctic Basin

    E-Print Network [OSTI]

    Vitaly V. Bulatov; Yuriy V. Vladimirov

    2012-06-26T23:59:59.000Z

    In this paper, we consider fundamental problems of the dynamics of internal gravity waves. We present analytical and numerical algorithms for calculating the wave fields for a set of values of the parameters, as observed in the ocean. We show that our mathematical models can describe the wave dynamics of the Arctic Basin, taking into account the actual physical characteristics of sea water, topography of its floor, etc. The numerical and analytical results show that the internal gravity waves have a significant effect on underwater sea objects in the Arctic Basin.

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

    SciTech Connect (OSTI)

    Cassano, John [Principal Investigator

    2013-06-30T23:59:59.000Z

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

  17. Intercomparison of cloud model simulations of Arctic mixed-phase boundary layer clouds observed during

    E-Print Network [OSTI]

    Zuidema, Paquita

    /crystal concentration also suggests the need for improved understanding of ice nucleation and its parameterizationIntercomparison of cloud model simulations of Arctic mixed-phase boundary layer clouds observed is presented. This case study is based on observations of a persistent mixed-phase boundary layer cloud

  18. The controls on net ecosystem productivity along an Arctic transect: a model comparison with ux

    E-Print Network [OSTI]

    The controls on net ecosystem productivity along an Arctic transect: a model comparison with ¯ux , * J O S E P H P . M C F A D D E N ² and F . S T U A R T C H A P I N I I I ² 2 *The Ecosystems Center ecosystem CO2-exchange data along a transect in northern Alaska. We use an extant process-based model

  19. Study Of The Fundamental Physical Principles in Atmospheric Modeling Based On Identification Of Atmosphere - Climate Control Factors: Bromine Explosion At The Polar Arctic Sunrise

    E-Print Network [OSTI]

    M. Iudin

    2010-07-09T23:59:59.000Z

    We attempt is to provide accumulated evidence and qualitative understanding of the associated atmospheric phenomena of the Arctic bromine explosion and their role in the functioning of the biotic Earth. We rationalize the empirical expression of the bromine influx into atmospheric boundary layer and calculate total amounts of the tropospheric BrO and Bry of the Arctic origin. Based on the quantities and partitioning of the reactive bromine species, we estimate the biogeochemical parametric constraint on the surface ozone field of the springtime NH. The constraint expresses strong relationship between atmosphere-climate control factors of the Earth's life and of external energy source. Physical atmosphere can be seen as a complex network of maximum complexity. Henceforth, we analyze the network context of the Arctic bromine pollution. We suggest that demonstrated attitudinal approach to the distributed surface flux would be successfully used in the innovative atmospheric modeling. The analysis is illustrated by GEM model results which stay in a good agreement with the observational data and support the original idea of the global NH effect of bromine chemistry.

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

    SciTech Connect (OSTI)

    Gutowski, William J.

    2013-02-07T23:59:59.000Z

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

  1. Source attributions of pollution to the Western Arctic during the NASA ARCTAS field campaign

    E-Print Network [OSTI]

    2013-01-01T23:59:59.000Z

    multi-model assessment of pollution transport to the Arctic,Oscillation controls air pollution transport to the Arctic,al. : Source attributions of pollution to the Western Arctic

  2. Next-Generation Ecosystem Experiments NGEE Arctic Quarterly Report

    E-Print Network [OSTI]

    to improve representation of the Arctic in Earth System Models Topography influences snow cover, thermal

  3. Modeling the formation and fate of the nearsurface temperature maximum in the Canadian Basin of the Arctic Ocean

    E-Print Network [OSTI]

    Zhang, Jinlun

    at the end of summer 2007, using both model output (described in section 2) and observed data. [3] Jackson et of the Arctic Ocean over the years 2000­2009. The NSTM is formed from local summertime absorption of solar., 2008; Nghiem et al., 2007]. This allowed 500% more solar energy into the surface layers of the Beaufort

  4. Arctic Landscapes --Complex, Connected and Vulnerable to a Changing Climate Geophysical Dynamics

    E-Print Network [OSTI]

    and reliability of climate projections. Earth System Models Models serve as tools for integration and synthesis-atmosphere interactions and their representation in Earth Systems Models. Land-Atmosphere Interactions Land surface for projections of future climate. Representation of heterogene- ity in Earth System Models will be advanced

  5. Time varying arctic climate change amplification

    SciTech Connect (OSTI)

    Chylek, Petr [Los Alamos National Laboratory; Dubey, Manvendra K [Los Alamos National Laboratory; Lesins, Glen [DALLHOUSIE U; Wang, Muyin [NOAA/JISAO

    2009-01-01T23:59:59.000Z

    During the past 130 years the global mean surface air temperature has risen by about 0.75 K. Due to feedbacks -- including the snow/ice albedo feedback -- the warming in the Arctic is expected to proceed at a faster rate than the global average. Climate model simulations suggest that this Arctic amplification produces warming that is two to three times larger than the global mean. Understanding the Arctic amplification is essential for projections of future Arctic climate including sea ice extent and melting of the Greenland ice sheet. We use the temperature records from the Arctic stations to show that (a) the Arctic amplification is larger at latitudes above 700 N compared to those within 64-70oN belt, and that, surprisingly; (b) the ratio of the Arctic to global rate of temperature change is not constant but varies on the decadal timescale. This time dependence will affect future projections of climate changes in the Arctic.

  6. A New Double-Moment Microphysics Parameterization for Application in Cloud and Climate Models. Part II: Single-Column Modeling of Arctic Clouds

    E-Print Network [OSTI]

    Shupe, Matthew

    of the arctic bound- ary layer, the presence of leads (cracks) in the sea ice surface, the persistence of mixed-phaseA New Double-Moment Microphysics Parameterization for Application in Cloud and Climate Models. Part- dicted cloud boundaries and total cloud fraction compare reasonably well with observations. Cloud phase

  7. Arctic house

    E-Print Network [OSTI]

    Turkel, Joel A. (Joel Abram), 1969-

    1999-01-01T23:59:59.000Z

    Currently available housing in the Arctic is limited to solutions that have been adapted from designs for less severe climates. This thesis has developed a new manner of residential construction designed specifically for ...

  8. Process-model Simulations of Cloud Albedo Enhancement by Aerosols in the Arctic

    SciTech Connect (OSTI)

    Kravitz, Benjamin S.; Wang, Hailong; Rasch, Philip J.; Morrison, H.; Solomon, Amy

    2014-11-17T23:59:59.000Z

    A cloud-resolving model is used to simulate the effectiveness of Arctic marine cloud brightening via injection of cloud condensation nuclei (CCN). An updated cloud microphysical scheme is employed, with prognostic CCN and cloud particle numbers in both liquid and mixed-phase marine low clouds. Injection of CCN into the marine boundary layer can delay the collapse of the boundary layer and increase low-cloud albedo. Because nearly all of the albedo effects are in the liquid phase due to the removal of ice water by snowfall when ice processes are involved, albedo increases are stronger for pure liquid clouds than mixed-phase clouds. Liquid precipitation can be suppressed by CCN injection, whereas ice precipitation (snow) is affected less; thus the effectiveness of brightening mixed-phase clouds is lower than for liquid-only clouds. CCN injection into a clean regime results in a greater albedo increase than injection into a polluted regime, consistent with current knowledge about aerosol-cloud interactions. Unlike previous studies investigating warm clouds, dynamical changes in circulation due to precipitation changes are small.

  9. Model-data Fusion Approaches for Retrospective and Predictive Assessment of the Pan-Arctic Scale Permafrost Carbon Feedback to Global Climate

    E-Print Network [OSTI]

    representation of the Arctic system carbon cycle in Earth System Modeling frameworks. This proposed study of permafrost carbon processes in terrestrial biogeochemistry models, to operate within coupled Earth system modeling frameworks. PROJECT SIGNIFICANCE This work will provide a critical bridge between the abundant

  10. Investigation of Microphysical Parameterizations of Snow and Ice in Arctic Clouds during M-PACE through ModelObservation Comparisons

    E-Print Network [OSTI]

    Solomon, Amy

    Investigation of Microphysical Parameterizations of Snow and Ice in Arctic Clouds during M the microphysical properties of Arctic mixed-phase stratocumulus. Intensive measurements taken during the Department of Energy Atmospheric Radiation Measurement Program Mixed-Phase Arctic Cloud Experiment (M

  11. A Climatology of the Arctic on Mid-Tropospheric Temperature Regulation

    E-Print Network [OSTI]

    Anthony, Jeremy Patrick

    2014-06-24T23:59:59.000Z

    The Arctic is a unique and complex environment. Many factors play a role in determining the long-term climate of the Arctic, including mesoscale weather systems and many complex ice-albedo feedback mechanisms. Previous studies determined using real...

  12. arctic ocean experiment: Topics by E-print Network

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

    Arctic Geosciences Websites Summary: Model predicted warming per century, Bitz et al In a global warming scenario, the Poles warm faster1 2012 Changing Arctic Ocean 506E497E -...

  13. arctic environmental change: Topics by E-print Network

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

    Arctic Geosciences Websites Summary: Model predicted warming per century, Bitz et al In a global warming scenario, the Poles warm faster1 2012 Changing Arctic Ocean 506E497E -...

  14. THE SHRINKING ARCTIC ICE CAP From the IPCC* Summary For Policymakers...

    E-Print Network [OSTI]

    THE SHRINKING ARCTIC ICE CAP From the IPCC* Summary For Policymakers... "Sea ice is projected] - a phenomenon sometimes referred to as "Arctic amplification". As Arctic temperatures rise, sea ice melts for the 20th century. The rate at which the modeled 21st century Arctic warming and sea ice melting occurs

  15. Intercomparison of model simulations of mixed-phase clouds observed during the ARM Mixed-Phase Arctic Cloud Experiment. Part II: Multi-layered cloud

    SciTech Connect (OSTI)

    Morrison, H; McCoy, R B; Klein, S A; Xie, S; Luo, Y; Avramov, A; Chen, M; Cole, J; Falk, M; Foster, M; Genio, A D; Harrington, J; Hoose, C; Khairoutdinov, M; Larson, V; Liu, X; McFarquhar, G; Poellot, M; Shipway, B; Shupe, M; Sud, Y; Turner, D; Veron, D; Walker, G; Wang, Z; Wolf, A; Xu, K; Yang, F; Zhang, G

    2008-02-27T23:59:59.000Z

    Results are presented from an intercomparison of single-column and cloud-resolving model simulations of a deep, multi-layered, mixed-phase cloud system observed during the ARM Mixed-Phase Arctic Cloud Experiment. This cloud system was associated with strong surface turbulent sensible and latent heat fluxes as cold air flowed over the open Arctic Ocean, combined with a low pressure system that supplied moisture at mid-level. The simulations, performed by 13 single-column and 4 cloud-resolving models, generally overestimate the liquid water path and strongly underestimate the ice water path, although there is a large spread among the models. This finding is in contrast with results for the single-layer, low-level mixed-phase stratocumulus case in Part I of this study, as well as previous studies of shallow mixed-phase Arctic clouds, that showed an underprediction of liquid water path. The overestimate of liquid water path and underestimate of ice water path occur primarily when deeper mixed-phase clouds extending into the mid-troposphere were observed. These results suggest important differences in the ability of models to simulate Arctic mixed-phase clouds that are deep and multi-layered versus shallow and single-layered. In general, models with a more sophisticated, two-moment treatment of the cloud microphysics produce a somewhat smaller liquid water path that is closer to observations. The cloud-resolving models tend to produce a larger cloud fraction than the single-column models. The liquid water path and especially the cloud fraction have a large impact on the cloud radiative forcing at the surface, which is dominated by the longwave flux for this case.

  16. Refiners Switch to RFG Complex Model

    Reports and Publications (EIA)

    1998-01-01T23:59:59.000Z

    On January 1, 1998, domestic and foreign refineries and importers must stop using the "simple" model and begin using the "complex" model to calculate emissions of volatile organic compounds (VOC), toxic air pollutants (TAP), and nitrogen oxides (NOx) from motor gasoline. The primary differences between application of the two models is that some refineries may have to meet stricter standards for the sulfur and olefin content of the reformulated gasoline (RFG) they produce and all refineries will now be held accountable for NOx emissions. Requirements for calculating emissions from conventional gasoline under the anti-dumping rule similarly change for exhaust TAP and NOx. However, the change to the complex model is not expected to result in an increase in the price premium for RFG or constrain supplies.

  17. The Role of Circulation Features on Black Carbon Transport into the Arctic in the Community Atmosphere Model Version 5 (CAM5)

    SciTech Connect (OSTI)

    Ma, Po-Lun; Rasch, Philip J.; Wang, Hailong; Zhang, Kai; Easter, Richard C.; Tilmes, S.; Fast, Jerome D.; Liu, Xiaohong; Yoon, Jin-Ho; Lamarque, Jean-Francois

    2013-05-28T23:59:59.000Z

    Current climate models generally under-predict the surface concentration of black carbon (BC) in the Arctic due to the uncertainties associated with emissions, transport, and removal. This bias is also present in the Community Atmosphere Model Version 5.1 (CAM5). In this study, we investigate the uncertainty of Arctic BC due to transport processes simulated by CAM5 by configuring the model to run in an “offline mode” in which the large-scale circulations are prescribed. We compare the simulated BC transport when the offline model is driven by the meteorology predicted by the standard free-running CAM5 with simulations where the meteorology is constrained to agree with reanalysis products. Some circulation biases are apparent: the free-running CAM5 produces about 50% less transient eddy transport of BC than the reanalysis-driven simulations, which may be attributed to the coarse model resolution insufficient to represent eddies. Our analysis shows that the free-running CAM5 reasonably captures the essence of the Arctic Oscillation (AO), but some discernable differences in the spatial pattern of the AO between the free-running CAM5 and the reanalysis-driven simulations result in significantly different AO modulation of BC transport over Northeast Asia and Eastern Europe. Nevertheless, we find that the overall climatological circulation patterns simulated by the free-running CAM5 generally resembles those from the reanalysis products, and BC transport is very similar in both simulation sets. Therefore, the simulated circulation features regulating the long-range BC transport is unlikely the most important cause of the large under-prediction of surface BC concentration in the Arctic.

  18. Intercomparison of cloud model simulations of Arctic mixed-phase boundary layer clouds observed during SHEBA/FIRE-ACE

    SciTech Connect (OSTI)

    Morrison, H.; Zuidema, Paquita; Ackerman, Andrew; Avramov, Alexander; de Boer, Gijs; Fan, Jiwen; Fridlind, Ann; Hashino, Tempei; Harrington, Jerry Y.; Luo, Yali; Ovchinnikov, Mikhail; Shipway, Ben

    2011-06-16T23:59:59.000Z

    An intercomparison of six cloud-resolving and large-eddy simulation models is presented. This case study is based on observations of a persistent mixed-phase boundary layer cloud gathered on 7 May, 1998 from the Surface Heat Budget of Arctic Ocean (SHEBA) and First ISCCP Regional Experiment - Arctic Cloud Experiment (FIRE-ACE). Ice nucleation is constrained in the simulations in a way that holds the ice crystal concentration approximately fixed, with two sets of sensitivity runs in addition to the baseline simulations utilizing different specified ice nucleus (IN) concentrations. All of the baseline and sensitivity simulations group into two distinct quasi-steady states associated with either persistent mixed-phase clouds or all-ice clouds after the first few hours of integration, implying the existence of multiple equilibria. These two states are associated with distinctly different microphysical, thermodynamic, and radiative characteristics. Most but not all of the models produce a persistent mixed-phase cloud qualitatively similar to observations using the baseline IN/crystal concentration, while small increases in the IN/crystal concentration generally lead to rapid glaciation and conversion to the all-ice state. Budget analysis indicates that larger ice deposition rates associated with increased IN/crystal concentrations have a limited direct impact on dissipation of liquid in these simulations. However, the impact of increased ice deposition is greatly enhanced by several interaction pathways that lead to an increased surface precipitation flux, weaker cloud top radiative cooling and cloud dynamics, and reduced vertical mixing, promoting rapid glaciation of the mixed-phase cloud for deposition rates in the cloud layer greater than about 1-2x10-5 g kg-1 s-1. These results indicate the critical importance of precipitation-radiative-dynamical interactions in simulating cloud phase, which have been neglected in previous fixed-dynamical parcel studies of the cloud phase parameter space. Large sensitivity to the IN/crystal concentration also suggests the need for improved understanding of ice nucleation and its parameterization in models.

  19. Carbon dynamics in arctic vegetation 

    E-Print Network [OSTI]

    Street, Lorna Elizabeth

    2011-11-24T23:59:59.000Z

    Rapid climate change in Arctic regions is of concern due to important feedbacks between the Arctic land surface and the global climate system. A large amount of organic carbon (C) is currently stored in Arctic soils; if ...

  20. Automatic Model Complexity Control Using Marginalized Discriminative Growth Functions

    E-Print Network [OSTI]

    Hain, Thomas

    Automatic model complexity control . Most LVCSR systems are trained on large amounts of data. . ManyAutomatic Model Complexity Control Using Marginalized Discriminative Growth Functions X. Liu & M. J. J. F. Gales: Automatic Model Complexity Control Using Marginalized Discriminative Growth Functions

  1. NREL's System Advisor Model Simplifies Complex Energy Analysis...

    Office of Scientific and Technical Information (OSTI)

    NREL's System Advisor Model Simplifies Complex Energy Analysis (Fact Sheet) Re-direct Destination: NREL has developed a tool -- the System Advisor Model (SAM) -- that can help...

  2. Interactive Distributed Ray Tracing of Highly Complex Models

    E-Print Network [OSTI]

    Wald, Ingo

    projects dealing with entire cars, ships, buildings, and processing plants. The complexity of such modelsInteractive Distributed Ray Tracing of Highly Complex Models Ingo Wald, Philipp Slusallek, Carsten- ulation of huge and complex 3D environments. Examples include large structural and mechanical engineering

  3. Probing a Paleoclimate Model-Data Misfit in Arctic Alaska from the Cretaceous Greenhouse World

    E-Print Network [OSTI]

    Lollar, Joseph Chad

    2011-08-31T23:59:59.000Z

    results of Ufnar et al. (2004b), but do not match those predicted by the Earth System modeling of Poulsen et al. (2007). These new data clearly emphasize the need for much more additional sampling in order to adequately characterize the hydrologic cycle...

  4. Model-Data Fusion Studies of Pacific Arctic Climate and Ice-Ocean Processes Jia Wang1, Hajo Eicken2, Yanling Yu3, X. Bai4, Jinlun Zhang3, H. Hu4, Moto Ikeda5, Kohei

    E-Print Network [OSTI]

    Zhang, Jinlun

    and Ecosystems Research (CILER), School of Natural Resources and Environment, University of Michigan, 4840 South1 Model-Data Fusion Studies of Pacific Arctic Climate and Ice-Ocean Processes Jia Wang1, Hajo. Tel: 734-741-2281; Email: Jia.Wang@noaa.gov 2. University of Alaska Fairbanks, Geophysical Institute

  5. Mechanistic kinetic modeling of the hydrocracking of complex feedstocks

    E-Print Network [OSTI]

    Kumar, Hans

    2009-05-15T23:59:59.000Z

    Two separate mechanistic kinetic models have been developed for the hydrocracking of complex feedstocks. The first model is targeted for the hydrocracking of vacuum gas oil. The second one addresses specifically the hydrocracking of long...

  6. Robust nite-di erence modelling of complex structures1

    E-Print Network [OSTI]

    Oprsal, Ivo

    with the 1Proc. of HIGH PERFORMANCE COMPUTING IN SEISMIC MODELLING, An International Sympo- sium, Zaragoza-difference modelling of complex structures Paper No. 15 in Proc. of Int. Symposium on High Performance Computing

  7. Bayesian Spatial Modeling of Complex and High Dimensional Data

    E-Print Network [OSTI]

    Konomi, Bledar

    2012-02-14T23:59:59.000Z

    The main objective of this dissertation is to apply Bayesian modeling to different complex and high-dimensional spatial data sets. I develop Bayesian hierarchical spatial models for both the observed location and the observation variable. Throughout...

  8. Modeling the impact of complexity on transportation

    E-Print Network [OSTI]

    Fernandez, Jose A. (Jose Antonio Fernandez Chavira)

    2012-01-01T23:59:59.000Z

    This thesis aimed to understand the drivers of total transportation costs during supply chain complexity events, in particular new product launches, in a fast moving consumer goods company in the United States. The research ...

  9. FIRST PRINCIPLES MODELING FOR LIDAR SENSING OF COMPLEX ICE SURFACES

    E-Print Network [OSTI]

    Kerekes, John

    FIRST PRINCIPLES MODELING FOR LIDAR SENSING OF COMPLEX ICE SURFACES J. Kerekes, A. Goodenough, S of monitoring the dynamics and mass balance of glaciers, ice caps, and ice sheets. However, it is also known that ice surfaces can have complex 3-dimensional structure, which can challenge their accurate retrieval

  10. Bayesian Networks and Evidence Theory to Model Complex Systems Reliability

    E-Print Network [OSTI]

    Paris-Sud XI, Université de

    , infrastructure of water distribution or electricity. The reliability studies of such systems are consequentlyBayesian Networks and Evidence Theory to Model Complex Systems Reliability Ch. SIMON, Ph. WEBER, E.levrat}@cran.uhp-nancy.fr Abstract-- This paper deals with the use of Bayesian Net- works to compute system reliability of complex

  11. 6, 96559722, 2006 Arctic smoke

    E-Print Network [OSTI]

    Boyer, Edmond

    Discussions Arctic smoke ­ record high air pollution levels in the European Arctic due to agricultural fires into the European Arctic and caused the most severe air pollution episodes ever recorded there. This paper confirms that biomass burning (BB) was in-5 deed the source of the observed air pollution, studies the transport

  12. arctic ocean ice: Topics by E-print Network

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

    AD of transient model simulations and a new type of sen- sitivity experiments with artificial sea ice growth Born, Andreas 320 The Thinning of Arctic Sea Ice, 19882003: Have...

  13. arctic cloud experiment: Topics by E-print Network

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

    low-level Arctic clouds in cold seasons and have a significant impact on the surface energy budget. However, the treatment of mixed-phase clouds in most current climate models...

  14. arctic ocean freshwater: Topics by E-print Network

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

    Geosciences Websites Summary: Model predicted warming per century, Bitz et al In a global warming scenario, the Poles warm faster1 2012 Changing Arctic Ocean 506E497E -...

  15. Modeling Power Systems as Complex Adaptive Systems

    SciTech Connect (OSTI)

    Chassin, David P.; Malard, Joel M.; Posse, Christian; Gangopadhyaya, Asim; Lu, Ning; Katipamula, Srinivas; Mallow, J V.

    2004-12-30T23:59:59.000Z

    Physical analogs have shown considerable promise for understanding the behavior of complex adaptive systems, including macroeconomics, biological systems, social networks, and electric power markets. Many of today's most challenging technical and policy questions can be reduced to a distributed economic control problem. Indeed, economically based control of large-scale systems is founded on the conjecture that the price-based regulation (e.g., auctions, markets) results in an optimal allocation of resources and emergent optimal system control. This report explores the state-of-the-art physical analogs for understanding the behavior of some econophysical systems and deriving stable and robust control strategies for using them. We review and discuss applications of some analytic methods based on a thermodynamic metaphor, according to which the interplay between system entropy and conservation laws gives rise to intuitive and governing global properties of complex systems that cannot be otherwise understood. We apply these methods to the question of how power markets can be expected to behave under a variety of conditions.

  16. Modeling in dyadic protocols for training complex skills

    E-Print Network [OSTI]

    Jordan, Jeffrey Alan

    1991-01-01T23:59:59.000Z

    MODELING IN DYADIC PROTOCOLS FOR TRAINING COMPLEX SKILLS A Thesis by JEFFREY ALAN JORDAN Submitted to the Office of Graduate Studies of Texas A&M University in partial fulfillment of the requirements for the degree of MASTER OF SCIENCE...) Charles FL Shea (Member) t n Worchel / e d of Department) / December 1991 ABSTRACT Modeling in Dyadic Protocols for Training Complex Skills. (December 1991) Jeffrey Alan Jordan, B. S. , Texas A&M University Chair of Advisory Committee: Dr. Wayne...

  17. Completeness and Complexity of Bounded Model Checking #

    E-Print Network [OSTI]

    Ouaknine, Joël

    of an exponent between this procedure and standard LTL model checking. We discuss ways to bridge this gap by the Semiconductor Research Corporation (SRC) under contract no. 99­TJ­684, the National Science Foundation (NSF

  18. Completeness and Complexity of Bounded Model Checking

    E-Print Network [OSTI]

    Ouaknine, Joël

    of an exponent between this procedure and standard LTL model checking. We discuss ways to bridge this gap reaches some pre-computed threshold, which indicates that This research is supported by the Semiconductor

  19. Intercomparison of model simulations of mixed-phase clouds observed during the ARM Mixed-Phase Arctic Cloud Experiment. Part I: Single layer cloud

    SciTech Connect (OSTI)

    Klein, S A; McCoy, R B; Morrison, H; Ackerman, A; Avramov, A; deBoer, G; Chen, M; Cole, J; DelGenio, A; Golaz, J; Hashino, T; Harrington, J; Hoose, C; Khairoutdinov, M; Larson, V; Liu, X; Luo, Y; McFarquhar, G; Menon, S; Neggers, R; Park, S; Poellot, M; von Salzen, K; Schmidt, J; Sednev, I; Shipway, B; Shupe, M; Spangenberg, D; Sud, Y; Turner, D; Veron, D; Falk, M; Foster, M; Fridlind, A; Walker, G; Wang, Z; Wolf, A; Xie, S; Xu, K; Yang, F; Zhang, G

    2008-02-27T23:59:59.000Z

    Results are presented from an intercomparison of single-column and cloud-resolving model simulations of a cold-air outbreak mixed-phase stratocumulus cloud observed during the Atmospheric Radiation Measurement (ARM) program's Mixed-Phase Arctic Cloud Experiment. The observed cloud occurred in a well-mixed boundary layer with a cloud top temperature of -15 C. The observed liquid water path of around 160 g m{sup -2} was about two-thirds of the adiabatic value and much greater than the mass of ice crystal precipitation which when integrated from the surface to cloud top was around 15 g m{sup -2}. The simulations were performed by seventeen single-column models (SCMs) and nine cloud-resolving models (CRMs). While the simulated ice water path is generally consistent with the observed values, the median SCM and CRM liquid water path is a factor of three smaller than observed. Results from a sensitivity study in which models removed ice microphysics indicate that in many models the interaction between liquid and ice-phase microphysics is responsible for the large model underestimate of liquid water path. Despite this general underestimate, the simulated liquid and ice water paths of several models are consistent with the observed values. Furthermore, there is some evidence that models with more sophisticated microphysics simulate liquid and ice water paths that are in better agreement with the observed values, although considerable scatter is also present. Although no single factor guarantees a good simulation, these results emphasize the need for improvement in the model representation of mixed-phase microphysics. This case study, which has been well observed from both aircraft and ground-based remote sensors, could be a benchmark for model simulations of mixed-phase clouds.

  20. Unified Modeling of Complex Real-Time Control Systems

    E-Print Network [OSTI]

    Hai, He; Chi-Lan, Cai

    2011-01-01T23:59:59.000Z

    Complex real-time control system is a software dense and algorithms dense system, which needs modern software engineering techniques to design. UML is an object-oriented industrial standard modeling language, used more and more in real-time domain. This paper first analyses the advantages and problems of using UML for real-time control systems design. Then, it proposes an extension of UML-RT to support time-continuous subsystems modeling. So we can unify modeling of complex real-time control systems on UML-RT platform, from requirement analysis, model design, simulation, until generation code.

  1. Intercomparison of model simulations of mixed-phase clouds observed during the ARM Mixed-Phase Arctic Cloud Experiment. Part I: Single layer cloud

    SciTech Connect (OSTI)

    Klein, Stephen A.; McCoy, Renata B.; Morrison, Hugh; Ackerman, Andrew S.; Avramov, Alexander; de Boer, Gijs; Chen, Mingxuan; Cole, Jason N.S.; Del Genio, Anthony D.; Falk, Michael; Foster, Michael J.; Fridlind, Ann; Golaz, Jean-Christophe; Hashino, Tempei; Harrington, Jerry Y.; Hoose, Corinna; Khairoutdinov, Marat F.; Larson, Vincent E.; Liu, Xiaohong; Luo, Yali; McFarquhar, Greg M.; Menon, Surabi; Neggers, Roel A. J.; Park, Sungsu; Poellot, Michael R.; Schmidt, Jerome M.; Sednev, Igor; Shipway, Ben J.; Shupe, Matthew D.; Spangenberg, Douglas A.; Sud, Yogesh C.; Turner, David D.; Veron, Dana E.; von Salzen, Knut; Walker, Gregory K.; Wang, Zhien; Wolf, Audrey B.; Xie, Shaocheng; Xu, Kuan-Man; Yang, Fanglin; Zhang, Gong

    2009-02-02T23:59:59.000Z

    Results are presented from an intercomparison of single-column and cloud-resolving model simulations of a cold-air outbreak mixed-phase stratocumulus cloud observed during the Atmospheric Radiation Measurement (ARM) program's Mixed-Phase Arctic Cloud Experiment. The observed cloud occurred in a well-mixed boundary layer with a cloud top temperature of -15 C. The observed average liquid water path of around 160 g m{sup -2} was about two-thirds of the adiabatic value and much greater than the average mass of ice crystal precipitation which when integrated from the surface to cloud top was around 15 g m{sup -2}. The simulations were performed by seventeen single-column models (SCMs) and nine cloud-resolving models (CRMs). While the simulated ice water path is generally consistent with the observed values, the median SCM and CRM liquid water path is a factor of three smaller than observed. Results from a sensitivity study in which models removed ice microphysics suggest that in many models the interaction between liquid and ice-phase microphysics is responsible for the large model underestimate of liquid water path. Despite this general underestimate, the simulated liquid and ice water paths of several models are consistent with the observed values. Furthermore, there is evidence that models with more sophisticated microphysics simulate liquid and ice water paths that are in better agreement with the observed values, although considerable scatter is also present. Although no single factor guarantees a good simulation, these results emphasize the need for improvement in the model representation of mixed-phase microphysics.

  2. Coastal Structures Modeling Complex | Open Energy Information

    Open Energy Info (EERE)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page onYou are now leaving Energy.gov You are now leaving Energy.gov You are beingZealand JumpConceptual Model, clickInformationNew York: Energy ResourcesCoastal Structures Modeling

  3. Ice Formation in Arctic Mixed-Phase Clouds: Insights from a 3-D Cloud-Resolving Model with Size-Resolved Aerosol and Cloud Microphysics

    SciTech Connect (OSTI)

    Fan, Jiwen; Ovtchinnikov, Mikhail; Comstock, Jennifer M.; McFarlane, Sally A.; Khain, Alexander

    2009-02-27T23:59:59.000Z

    The single-layer mixed-phase clouds observed during the Atmospheric Radiation Measurement (ARM) program’s Mixed-Phase Arctic Cloud Experiment (MPACE) are simulated with a 3-dimensional cloud-resolving model the System for Atmospheric Modeling (SAM) coupled with an explicit bin microphysics scheme and a radar-lidar simulator. Two possible ice enhancement mechanisms – activation of droplet evaporation residues by condensation-followed-by-freezing and droplet freezing by contact freezing inside-out, are scrutinized by extensive comparisons with aircraft and radar and lidar measurements. The locations of ice initiation associated with each mechanism and the role of ice nuclei (IN) in the evolution of mixed-phase clouds are mainly addressed. Simulations with either mechanism agree well with the in-situ and remote sensing measurements on ice microphysical properties but liquid water content is slightly underpredicted. These two mechanisms give very similar cloud microphysical, macrophysical, dynamical, and radiative properties, although the ice nucleation properties (rate, frequency and location) are completely different. Ice nucleation from activation of evaporation nuclei is most efficient near cloud top areas concentrated on the edges of updrafts, while ice initiation from the drop freezing process has no significant location preference (occurs anywhere that droplet evaporation is significant). Both enhanced nucleation mechanisms contribute dramatically to ice formation with ice particle concentration of 10-15 times higher relative to the simulation without either of them. The contribution of ice nuclei (IN) recycling from ice particle evaporation to IN and ice particle concentration is found to be very significant in this case. Cloud can be very sensitive to IN initially and form a nonquilibrium transition condition, but become much less sensitive as cloud evolves to a steady mixed-phase condition. The parameterization of Meyers et al. [1992] with the observed MPACE IN concentration is able to predict the observed mixed-phase clouds reasonably well. This validation may facilitate the application of this parameterization in the cloud and climate models to simulate Arctic clouds.

  4. Single-Step Stereolithography of Complex Anatomical Models

    E-Print Network [OSTI]

    Pekkan, Kerem

    Single-Step Stereolithography of Complex Anatomical Models for Optical Flow Measurements Diane de of Technology & Emory University School of Medicine, Room 2119 U.A. Whitaker Building, 313 Ferst Dr., Atlanta demonstrated in literature to be a practical model construction tool for optical flow measurements

  5. Energy-aware scheduling: models and complexity results

    E-Print Network [OSTI]

    Paris-Sud XI, Université de

    Energy-aware scheduling: models and complexity results Guillaume Aupy (1st year PhD student) LIP several energy-aware scheduling algorithms whose design is optimized for different speed models. Dynamic plans. I. INTRODUCTION Energy-aware scheduling has proven an important issue in the past decade, both

  6. Arctic ice islands

    SciTech Connect (OSTI)

    Sackinger, W.M.; Jeffries, M.O.; Lu, M.C.; Li, F.C.

    1988-01-01T23:59:59.000Z

    The development of offshore oil and gas resources in the Arctic waters of Alaska requires offshore structures which successfully resist the lateral forces due to moving, drifting ice. Ice islands are floating, a tabular icebergs, up to 60 meters thick, of solid ice throughout their thickness. The ice islands are thus regarded as the strongest ice features in the Arctic; fixed offshore structures which can directly withstand the impact of ice islands are possible but in some locations may be so expensive as to make oilfield development uneconomic. The resolution of the ice island problem requires two research steps: (1) calculation of the probability of interaction between an ice island and an offshore structure in a given region; and (2) if the probability if sufficiently large, then the study of possible interactions between ice island and structure, to discover mitigative measures to deal with the moving ice island. The ice island research conducted during the 1983-1988 interval, which is summarized in this report, was concerned with the first step. Monte Carlo simulations of ice island generation and movement suggest that ice island lifetimes range from 0 to 70 years, and that 85% of the lifetimes are less then 35 years. The simulation shows a mean value of 18 ice islands present at any time in the Arctic Ocean, with a 90% probability of less than 30 ice islands. At this time, approximately 34 ice islands are known, from observations, to exist in the Arctic Ocean, not including the 10-meter thick class of ice islands. Return interval plots from the simulation show that coastal zones of the Beaufort and Chukchi Seas, already leased for oil development, have ice island recurrences of 10 to 100 years. This implies that the ice island hazard must be considered thoroughly, and appropriate safety measures adopted, when offshore oil production plans are formulated for the Alaskan Arctic offshore. 132 refs., 161 figs., 17 tabs.

  7. Mathematical approaches for complexity/predictivity trade-offs in complex system models : LDRD final report.

    SciTech Connect (OSTI)

    Goldsby, Michael E.; Mayo, Jackson R.; Bhattacharyya, Arnab (Massachusetts Institute of Technology, Cambridge, MA); Armstrong, Robert C.; Vanderveen, Keith

    2008-09-01T23:59:59.000Z

    The goal of this research was to examine foundational methods, both computational and theoretical, that can improve the veracity of entity-based complex system models and increase confidence in their predictions for emergent behavior. The strategy was to seek insight and guidance from simplified yet realistic models, such as cellular automata and Boolean networks, whose properties can be generalized to production entity-based simulations. We have explored the usefulness of renormalization-group methods for finding reduced models of such idealized complex systems. We have prototyped representative models that are both tractable and relevant to Sandia mission applications, and quantified the effect of computational renormalization on the predictive accuracy of these models, finding good predictivity from renormalized versions of cellular automata and Boolean networks. Furthermore, we have theoretically analyzed the robustness properties of certain Boolean networks, relevant for characterizing organic behavior, and obtained precise mathematical constraints on systems that are robust to failures. In combination, our results provide important guidance for more rigorous construction of entity-based models, which currently are often devised in an ad-hoc manner. Our results can also help in designing complex systems with the goal of predictable behavior, e.g., for cybersecurity.

  8. Sandia National Laboratories: Arctic sea ice

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

    Arctic sea ice Sierra Unmanned Aerial Vehicle to Begin Flights Over Arctic Sea Ice On July 25, 2013, in Climate, Customers & Partners, Global, Monitoring, News, News & Events,...

  9. Optimal Synthesis of Complex Distillation ColumnsUsing Rigorous Models

    E-Print Network [OSTI]

    Grossmann, Ignacio E.

    a review of recent work for the optimal design of distillation of individual columns using tray review of the area of optimal design and synthesis of distillation columns, emphasizing recentOptimal Synthesis of Complex Distillation ColumnsUsing Rigorous Models Ignacio E. Grossmann1 , Pío

  10. A Hierarchical Model for Estimating the Reliability of Complex Systems

    E-Print Network [OSTI]

    Reese, Shane

    an approximation to the joint posterior distribution on the total system reliability was obtained. Many reliability or bounding moments of the system reliability posterior distribution (Cole (1975), Mastran (1976), DostalA Hierarchical Model for Estimating the Reliability of Complex Systems Valen E. Johnson, Todd L

  11. Free energy and complexity of spherical bipartite models

    E-Print Network [OSTI]

    Antonio Auffinger; Wei-Kuo Chen

    2014-05-09T23:59:59.000Z

    We investigate both free energy and complexity of the spherical bipartite spin glass model. We first prove a variational formula in high temperature for the limiting free energy based on the well-known Crisanti-Sommers representation of the mixed p-spin spherical model. Next, we show that the mean number of local minima at low levels of energy is exponentially large in the size of the system and we derive a bound on the location of the ground state energy.

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

    E-Print Network [OSTI]

    Monier, Erwan

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

  13. Coupling the high-complexity land surface model ACASA to the mesoscale model WRF

    E-Print Network [OSTI]

    Pyles, R. D.

    In this study, the Weather Research and Forecasting (WRF) model is coupled with the Advanced Canopy–Atmosphere–Soil Algorithm (ACASA), a high-complexity land surface model. Although WRF is a state-of-the-art regional ...

  14. Coupling the High Complexity Land Surface Model ACASA to the Mesoscale Model WRF

    E-Print Network [OSTI]

    Xu, L.

    In this study, the Weather Research and Forecasting Model (WRF) is coupled with the Advanced Canopy-Atmosphere-Soil Algorithm (ACASA), a high complexity land surface model. Although WRF is a state-of-the-art regional ...

  15. Long-Range Atmospheric Transport of Polycyclic Aromatic Hydrocarbons: A Global 3-D Model Analysis Including Evaluation of Arctic Sources

    E-Print Network [OSTI]

    Friedman, Carey

    We use the global 3-D chemical transport model GEOS-Chem to simulate long-range atmospheric transport of polycyclic aromatic hydrocarbons (PAHs). To evaluate the model’s ability to simulate PAHs with different volatilities, ...

  16. Modeling and Algorithmic Approaches to Constitutively-Complex, Microstructured Fluids

    SciTech Connect (OSTI)

    Miller, Gregory H.; Forest, Gregory

    2011-12-22T23:59:59.000Z

    We present a new multiscale model for complex uids based on three scales: microscopic, kinetic, and continuum. We choose the microscopic level as Kramers' bead-rod model for polymers, which we describe as a system of stochastic di#11;erential equations with an implicit constraint formulation. The associated Fokker-Planck equation is then derived, and adiabatic elimination removes the fast momentum coordinates. Approached in this way, the kinetic level reduces to a dispersive drift equation. The continuum level is modeled with a #12;nite volume Godunov-projection algorithm. We demonstrate computation of viscoelastic stress divergence using this multiscale approach.

  17. Potential Oil Production from the Coastal Plain of the Arctic...

    Annual Energy Outlook 2013 [U.S. Energy Information Administration (EIA)]

    Potential Oil Production from the Coastal Plain of the Arctic National Wildlife Refuge: Updated Assessment 1. Overview of the Arctic National Wildlife Refuge Background The Arctic...

  18. RHIC injector complex online model status and plans

    SciTech Connect (OSTI)

    Schoefer,V.; Ahrens, L.; Brown, K.; Morris, J.; Nemesure, S.

    2009-05-04T23:59:59.000Z

    An online modeling system is being developed for the RHIC injector complex, which consists of the Booster, the AGS and the transfer lines connecting the Booster to the AGS and the AGS to RHIC. Historically the injectors have been operated using static values from design specifications or offline model runs, but tighter beam optics constraints required by polarized proton operations (e.g, accelerating with near-integer tunes) have necessitated a more dynamic system. An online model server for the AGS has been implemented using MAD-X [1] as the model engine, with plans to extend the system to the Booster and the injector transfer lines and to add the option of calculating optics using the Polymorphic Tracking Code (PTC [2]) as the model engine.

  19. Defining and Model Checking Abstractions of Complex Railway Models using CSP||B

    E-Print Network [OSTI]

    Doran, Simon J.

    Defining and Model Checking Abstractions of Complex Railway Models using CSP||B Faron Moller1. In [11, 10] we propose a new modelling approach for railway interlockings. We use CSP||B [13], which involves events such as train movements and, in the interlocking, state based reasoning. In this sense, CSP

  20. Can dive cycle models predict patterns of foraging behaviour? Diving by common eiders in an Arctic polynya

    E-Print Network [OSTI]

    account for the capabilities and limitations of their respiratory system when making foraging decisions. Therefore, while static modelling ap- proaches are an important heuristic tool for elucidating mechanisms), obtaining oxygen (or exchang- ing other respiratory gases; Halsey et al. 2003a; Green et al. 2005

  1. ERS SAR characterization of coastal polynyas in the Arctic and comparison with SSM/I and numerical model investigations

    E-Print Network [OSTI]

    Winsor, Peter

    ), and a numerical polynya model (NPM) forced by National Center for Environmental Predictions (NCEP) wind fields increases to .83. The NPM computes offshore coastal polynya widths, heat exchange, and ice production is that SAR images processed through the SAR polynya algorithm in combination with the NPM is a powerful tool

  2. 1Earth System Models of Intermediate Complexity: Closing the Gap in the Spectrum of Climate System

    E-Print Network [OSTI]

    Martin Claussen; Michel Crucifix; Thierry Fichefet; Andrey Ganopolski; Huges Goosse; Vladimir Petoukhov; Thomas Stocker; Peter Stone; Zhaoming Wang; Andrew Weaver; Susanne L. Weber

    system models of intermediate complexity (EMICs) is discussed. It be-comes apparent that there exists a

  3. Data-flow graphs as a model of parallel complexity

    SciTech Connect (OSTI)

    Campbell, M.L.

    1987-01-01T23:59:59.000Z

    A new model of parallel computation based on data-flow graphs is introduced, which is specifically oriented towards complexity theory. Data-flow graphs are capable of illustrating properties of synchronous, asynchronous, and nondeterministic computations. Sufficient conditions are derived for asynchronous data-flow graphs to be determinate, i.e., all possible computations are finite and yield the same result. For determinate graphs, it is shown that the synchronous computation is as fast as any asynchronous computation. An algorithm is presented that transforms a nondeterminate data-flow graphs into a synchronous determinate one. The basic data-flow graph idea is extended into a model with greater potential parallelism, called the Uniform Data Flow Graph Family (UDFGF) Model. It is proved that time and space for the UDFGF model are polynomially related to reversal and space for the Turing Machine model, in both the deterministic and nondeterministic cases. In addition to forming an abstract computational model, data-flow graphs are parallel programs for real multiprocessors. Given a data flow graph program and a multiprocessor, each node of the graph must be assigned to one of the processors. It is proved that this problem is intractable, and a practical algorithm to find approximate solutions for it is presented.

  4. Canada's Arctic Gateway: Discussion Paper Summary

    E-Print Network [OSTI]

    Martin, Jeff

    Canada's Arctic Gateway: Discussion Paper Summary September 2010 The following summarizes key Canada's Arctic Gateway a reality in terms of both national public policy and international presence the Government of Canada's national gateway policy framework. This discussion paper's use of the term "Arctic

  5. Interannual Variations of Arctic Cloud Types

    E-Print Network [OSTI]

    Hochberg, Michael

    Sciences #12;Changes in Arctic Climate What is the role of cloud cover in Arctic climate change? What is the Cloud Radiative Effect (CRE) in the Arctic? #12;CRE depends on season, cloud type CRE ­ whether clouds specifically chosen to include nighttime obs Total cloud cover and nine cloud types: - High cloud (cirriform

  6. Interannual Variations of Arctic Cloud Types

    E-Print Network [OSTI]

    Hochberg, Michael

    Declining September sea-ice extent #12;Clouds & Changes in Arctic Climate What is the role of cloud cover in Arctic climate change? What is the Cloud Radiative Effect (CRE) in the Arctic? #12;CRE Defined CRE nighttime obs Total cloud cover and nine cloud types: - High cloud (cirriform) - Middle Clouds: Altocumulus

  7. Next-Generation Ecosystem Experiments NGEE Arctic Quarterly Report

    E-Print Network [OSTI]

    1 Next-Generation Ecosystem Experiments ­ NGEE Arctic Quarterly Report December 31, 2011 A progress Dynamics Model Used to Design Permafrost Simulator 2 Details at a Glance 3 Progress and Accomplishments 3 sample in a sleeve of highly conductive copper foil (shown in red) and then cooling coils placed

  8. Agents and artefacts for multiple models co-evolution Building complex system simulation as a set of interacting models

    E-Print Network [OSTI]

    Paris-Sud XI, Université de

    Agents and artefacts for multiple models co-evolution Building complex system simulation as a set of modelling style. [...] Thus the distinction in Cite as: AA4MM: Building complex system simulation as a set. The challenge is then to allow those scientists to build a complex simulation from their own building blocks

  9. arctic mixed-phase clouds: Topics by E-print Network

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

    low-level Arctic clouds in cold seasons and have a significant impact on the surface energy budget. However, the treatment of mixed-phase clouds in most current climate models...

  10. An AeroCom Assessment of Black Carbon in Arctic Snow and Sea Ice

    SciTech Connect (OSTI)

    Jiao, C.; Flanner, M. G.; Balkanski, Y.; Bauer, S.; Bellouin, N.; Berntsen, T.; Bian, Huisheng; Carslaw, K. S.; Chin, Mian; De Luca, N.; Diehl, Thomas; Ghan, Steven J.; Iversen, T.; Kirkevag, A.; Koch, Dorothy; Liu, Xiaohong; Mann, G. W.; Penner, Joyce E.; Pitari, G.; Schulz, M.; Seland, O.; Skeie, R. B.; Steenrod, Stephen D.; Stier, P.; Takemura, T.; Tsigaridis, Kostas; van Noije, T.; Yun, Yuxing; Zhang, Kai

    2014-03-07T23:59:59.000Z

    Though many global aerosols models prognose surface deposition, only a few models have been used to directly simulate the radiative effect from black carbon (BC) deposition to snow and sea-ice. Here, we apply aerosol deposition fields from 25 models contributing to two phases of the Aerosol Comparisons between Observations and Models (AeroCom) project to simulate and evaluate within snow BC concentrations and radiative effect in the Arctic. We accomplish this by driving the offline land and sea-ice components of the Community Earth System Model with different deposition fields and meteorological conditions from 2004-2009, during which an extensive field campaign of BC measurements in Arctic snow occurred. We find that models generally underestimate BC concentrations in snow in northern Russia and Norway, while overestimating BC amounts elsewhere in the Arctic. Although simulated BC distributions in snow are poorly correlated with measurements, mean values are reasonable. The multi-model mean (range) bias in BC concentrations, sampled over the same grid cells, snow depths, and months of measurements, are -4.4 (-13.2 to +10.7) ng g?1 for an earlier Phase of AeroCom models (Phase I), and +4.1 (-13.0 to +21.4) ng g?1 for a more recent Phase of AeroCom models (Phase II), compared to the observational mean of 19.2 ng g?1. Factors determining model BC concentrations in Arctic snow include Arctic BC emissions, transport of extra-Arctic aerosols, precipitation, deposition efficiency of aerosols within the Arctic, and meltwater removal of particles in snow. Sensitivity studies show that the model–measurement evaluation is only weakly affected by meltwater scavenging efficiency because most measurements were conducted in non-melting snow. The Arctic (60-90?N) atmospheric residence time for BC in Phase II models ranges from 3.7 to 23.2 days, implying large inter-model variation in local BC deposition efficiency. Combined with the fact that most Arctic BC deposition originates from extra-Arctic emissions, these results suggest that aerosol removal processes are a leading source of variation in model performance. The multi-model mean (full range) of Arctic radiative effect from BC in snow is 0.15 (0.07-0.25) W m?2 and 0.18 (0.06-0.28) W m?2 in Phase I and Phase II models, respectively. After correcting for model biases relative to observed BC concentrations in different regions of the Arctic, we obtain a multi-model mean Arctic radiative effect of 0.17 W m?2 for the combined AeroCom ensembles. Finally, there is a high correlation between modeled BC concentrations sampled over the observational sites and the Arctic as a whole, indicating that the field campaign provided a reasonable sample of the Arctic.

  11. The Thinning of Arctic Sea Ice, 19882003: Have We Passed a Tipping Point? R. W. LINDSAY AND J. ZHANG

    E-Print Network [OSTI]

    Zhang, Jinlun

    ­05. To determine the physical processes contributing to these changes in the Arctic pack ice, model results from ice pack is a key component of the Arctic Ocean physical and biological systems. It controls in the central pack is also thinning. Based on submarine measurements, the ice draft is reported by Rothrock et

  12. Long-term effects of anthropogenic CO2 emissions simulated with a complex earth system model

    E-Print Network [OSTI]

    Winguth, Arne

    Long-term effects of anthropogenic CO2 emissions simulated with a complex earth system model Uwe earth system model con- sisting of an atmospheric general circulation model, an ocean general

  13. Assessing complexity by means of maximum entropy models

    E-Print Network [OSTI]

    Chliamovitch, Gregor; Velasquez, Lino

    2014-01-01T23:59:59.000Z

    We discuss a characterization of complexity based on successive approximations of the probability density describing a system by means of maximum entropy methods, thereby quantifying the respective role played by different orders of interaction. This characterization is applied on simple cellular automata in order to put it in perspective with the usual notion of complexity for such systems based on Wolfram classes. The overlap is shown to be good, but not perfect. This suggests that complexity in the sense of Wolfram emerges as an intermediate regime of maximum entropy-based complexity, but also gives insights regarding the role of initial conditions in complexity-related issues.

  14. MODELING AND MEASUREMENT OF OPTICAL POLARIMETRIC IMAGE PHENOMENOLOGY IN A COMPLEX URBAN ENVIRONMENT

    E-Print Network [OSTI]

    Kerekes, John

    MODELING AND MEASUREMENT OF OPTICAL POLARIMETRIC IMAGE PHENOMENOLOGY IN A COMPLEX URBAN ENVIRONMENT be modeled and placed above a complex synthetic urban scene to create spectrally varying Stokes vector output generation (SIG) model [2]. A SIG can be configured for the same sun, scene, and sensor geometry as the real

  15. Introduction to Modelling and Control of Complex Systems P. Ioannou1

    E-Print Network [OSTI]

    Pitsillides, Andreas

    Chapter 1. Introduction to Modelling and Control of Complex Systems P. Ioannou1 , A. Pitsillides2 1 that the model of the system is so complex that it is difficult if at all possible to use existing control tools. For example a high order model could lead to a high order controller which could not be implemented due

  16. 2005: Table of EMICs (Earth System Models of Intermediate Complexity

    E-Print Network [OSTI]

    Martin Claussen

    apparent that Earth system modelling has to rely on a hierarchy of models in which models of intermediate

  17. NREL's System Advisor Model Simplifies Complex Energy Analysis...

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

    diversifying. In addition to fossil fuel- based power, decision makers can choose among solar, wind, and geothermal technologies as well. Each of these technologies has complex...

  18. Constructing Irregular Surfaces to Enclose Macromolecular Complexes for Mesoscale Modeling Using the Discrete

    E-Print Network [OSTI]

    Schlick, Tamar

    Constructing Irregular Surfaces to Enclose Macromolecular Complexes for Mesoscale Modeling Using proteins. DiSCO is generally applicable to other interesting macromolecular systems for which mesoscale

  19. Arctic Ecologies: The Politics and Poetics of Northern Literary Environments

    E-Print Network [OSTI]

    Athens, Allison Katherine

    2013-01-01T23:59:59.000Z

    Efforts: Creating an Arctic Home. ” Coca-Cola Arctic Home.Coca-Cola and WWF. Web. 10 Apr. 2013. “Arctic NationalHarvard UP, 1997. Print. “Coca-Cola: Building Support for

  20. Modeling Complex Organic Molecules in dense regions: Eley-Rideal and complex induced reaction

    E-Print Network [OSTI]

    Ruaud, M; Hickson, K M; Gratier, P; Hersant, F; Wakelam, V

    2014-01-01T23:59:59.000Z

    Recent observations have revealed the existence of Complex Organic Molecules (COMs) in cold dense cores and prestellar cores. The presence of these molecules in such cold conditions is not well understood and remains a matter of debate since the previously proposed "warm- up" scenario cannot explain these observations. In this article, we study the effect of Eley- Rideal and complex induced reaction mechanisms of gas-phase carbon atoms with the main ice components of dust grains on the formation of COMs in cold and dense regions. Based on recent experiments we use a low value for the chemical desorption efficiency (which was previously invoked to explain the observed COM abundances). We show that our introduced mechanisms are efficient enough to produce a large amount of complex organic molecules in the gas-phase at temperatures as low as 10K.

  1. Refinery fuel oxygenates in view of the complex model for reformulated gasline

    SciTech Connect (OSTI)

    Crawford, C.D.; Haelsig, C.P. [Fluor Daniel, Irvine, CA (United States)

    1994-12-31T23:59:59.000Z

    The final version of the Complex Model for reformulated gasoline (RFG) has now been issued with some surprising features that will significantly affect refinery fuel oxygenates planning. These include the following: (1) The only oxygenates included in the model are MTBE, ETBE, TAME, and Ethanol. (2) The Complex Model calculates that MTBE and TAME are significantly more effective for reduction of air toxics emissions than Ethanol and ETBE. (3) The Complex Model calculates that MTBE and TAME typically produce about equal reduction in air toxics emissions at the same RFG oxygen content. Although gasoline certification by the Complex Model is optional prior to 1998, after 1998 it will be mandatory for both reformulated and conventional gasolines. This paper considers refinery oxygenates production in view of these features of the Complex Model for RFG, basing the discussion on 2.0 weight percent oxygen content for RFG.

  2. arctic vegetation amplify: Topics by E-print Network

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

    dynamics in arctic vegetation Edinburgh, University of - Research Archive Summary: Rapid climate change in Arctic regions is of concern due to important feedbacks between the...

  3. airborne arctic stratospheric: Topics by E-print Network

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

    the Arctic System Reanalysis Natalia Tilinina1 , Sergey, Vienna MOTIVATION Key role of cyclone activity in the Arctic energy and hydrological cycles Cyclones impact on sea ice...

  4. arctic cloudy boundary: Topics by E-print Network

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

    the Arctic System Reanalysis Natalia Tilinina1 , Sergey, Vienna MOTIVATION Key role of cyclone activity in the Arctic energy and hydrological cycles Cyclones impact on sea ice...

  5. arctic ground squirrel: Topics by E-print Network

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

    the Arctic System Reanalysis Natalia Tilinina1 , Sergey, Vienna MOTIVATION Key role of cyclone activity in the Arctic energy and hydrological cycles Cyclones impact on sea ice...

  6. alesund arctic base: Topics by E-print Network

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

    the Arctic System Reanalysis Natalia Tilinina1 , Sergey, Vienna MOTIVATION Key role of cyclone activity in the Arctic energy and hydrological cycles Cyclones impact on sea ice...

  7. arctic stratospheric expedition: Topics by E-print Network

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

    the Arctic System Reanalysis Natalia Tilinina1 , Sergey, Vienna MOTIVATION Key role of cyclone activity in the Arctic energy and hydrological cycles Cyclones impact on sea ice...

  8. arctic ground squirrels: Topics by E-print Network

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

    the Arctic System Reanalysis Natalia Tilinina1 , Sergey, Vienna MOTIVATION Key role of cyclone activity in the Arctic energy and hydrological cycles Cyclones impact on sea ice...

  9. arctic shrub tundra: Topics by E-print Network

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

    Sites, Abandoned Dwellings, and Trampled Tundra in the Eastern Canadian Arctic: A Multivariate Analysis CiteSeer Summary: ABSTRACT. Arctic terrestrial ecosystems subjected...

  10. Potential Oil Production from the Coastal Plain of the Arctic...

    U.S. Energy Information Administration (EIA) Indexed Site

    Potential Oil Production from the Coastal Plain of the Arctic National Wildlife Refuge: Updated Assessment Preface Potential Oil Production from the Coastal Plain of the Arctic...

  11. arctic ecosystems dominated: Topics by E-print Network

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

    by: Arctic Institute of North America Stable URL: http Vermont, University of 7 Improved Climate Prediction through a System Level Understanding of Arctic Terrestrial Ecosystems...

  12. arctic ice islands: Topics by E-print Network

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

    analogous to the effects of the Arctic region; KEYWORDS: Arctic Ocean, ice rafting, climate change Citation: Darby, D. A., and J. F. Bischof (2004), A Holocene record of...

  13. Modelling the transition to complex, culturally transmitted communication 

    E-Print Network [OSTI]

    Ritchie, Graham R S

    2009-01-01T23:59:59.000Z

    Human language is undoubtedly one of the most complex and powerful communication systems to have evolved on Earth. Study of the evolution of this behaviour is made difficult by the lack of comparable communication systems ...

  14. Complexity cost quantification and modeling for strategic portfolio management

    E-Print Network [OSTI]

    Ma, Jan, S.M. Massachusetts Institute of Technology

    2014-01-01T23:59:59.000Z

    This project explores portfolio management and planning through effectively reducing complexity within operations. We apply this to a major healthcare company (referred to as Company X). The anticipated launch of new ...

  15. Arctic sea ice extent small as never before Alerting message from the Arctic: The extent the the Arctic sea ice has reached on Sep. 8

    E-Print Network [OSTI]

    Bremen, Universität

    Arctic sea ice extent small as never before Alerting message from the Arctic: The extent the the Arctic sea ice has reached on Sep. 8 with 4.240 million km2 a new historic minimum (Figure 1). Physicists of the University of Bremen now confirm the apprehension existing since July 2011 that the ice melt in the Arctic

  16. Modeling complex biological flows in multi-scale systems using the APDEC framework

    E-Print Network [OSTI]

    Modeling complex biological flows in multi-scale systems using the APDEC framework David Trebotich methods are based on higher-order finite difference methods in complex geometry with adaptivity-mail: trebotich1@llnl.gov Abstract. We have developed advanced numerical algorithms to model biological fluids

  17. Statistical Image Modeling with the Magnitude Probability Density Function of Complex Wavelet

    E-Print Network [OSTI]

    Oraintara, Soontorn

    Statistical Image Modeling with the Magnitude Probability Density Function of Complex Wavelet the probability density function (pdf) of the magnitude of complex wavelet coefficients with the assump- tion Statistical image modeling in the wavelet domain is of inter- est in recent years due to the ability

  18. Biodiesel Sim: Crowdsourcing Simulations for Complex Model Analysis Derek Riley, Xiaowei Zhang, Xenofon Koutsoukos

    E-Print Network [OSTI]

    Koutsoukos, Xenofon D.

    Biodiesel Sim: Crowdsourcing Simulations for Complex Model Analysis Derek Riley, Xiaowei Zhang Computation, Biodiesel Abstract Biodiesel is an alternative fuel source that can be easily made by novices of the proces- sor. A biodiesel processor is a complex system that can be modeled and simulated using formal

  19. CITPUFF: a gaussian puff model for estimating pollutant concentration in complex terrain. Forest Service research paper

    SciTech Connect (OSTI)

    Ross, D.G.; Fox, D.G.; Dietrich, D.L.; Childs, J.E.; Marlatt, W.E.

    1985-07-01T23:59:59.000Z

    CITPUFF, is a puff-type dispersion model that uses a wind field calculated from a complex-terrain wind model. It accommodates a variety of source types including point, area, and line sources; calculates plume rise where applicable; and outputs a graphic display of puff trajectories and concentrations. The model is compared against models currently used for assessing air quality impacts in complex topography.

  20. Primary production of arctic waters

    SciTech Connect (OSTI)

    Rao, D.V.S.; Platt, T.

    1984-01-01T23:59:59.000Z

    Using data that have become available during the last ten years they have reestimated the annual production by phytoplankton in the arctic marine ecosystem. The new figure is some sixteen times higher than an estimate made in 1975. This is of considerable significance regionally, but still does not, of itself, imply that global phytoplankton production is underestimated at present. 82 references, 3 figures, 9 tables.

  1. Information geometric complexity of a trivariate Gaussian statistical model

    E-Print Network [OSTI]

    D. Felice; C. Cafaro; S. Mancini

    2014-05-30T23:59:59.000Z

    We evaluate the information geometric complexity of entropic motion on low-dimensional Gaussian statistical manifolds in order to quantify how difficult is making macroscopic predictions about a systems in the presence of limited information. Specifically, we observe that the complexity of such entropic inferences not only depends on the amount of available pieces of information but also on the manner in which such pieces are correlated. Finally, we uncover that for certain correlational structures, the impossibility of reaching the most favorable configuration from an entropic inference viewpoint, seems to lead to an information geometric analog of the well-known frustration effect that occurs in statistical physics.

  2. Technology Characterization Models and Their Use in Designing Complex Systems

    E-Print Network [OSTI]

    Parker, Robert Reed

    2011-08-08T23:59:59.000Z

    , SHGF). In lieu of sending this model to an architect (to prevent divulging trade secrets or because the architect may not want to deal with these detailed models), the inventor could create a more abstracted model of the performance of his window...

  3. NREL's System Advisor Model Simplifies Complex Energy Analysis (Fact Sheet)

    SciTech Connect (OSTI)

    Not Available

    2011-10-01T23:59:59.000Z

    The energy market is diversifying. In addition to traditional power sources, decision makers can choose among solar, wind, and geothermal technologies as well. Each of these technologies has complex performance characteristics and economics that vary with location and other project specifics, making it difficult to analyze the viability of such projects. But that analysis is easier now, thanks to the National Renewable Energy Laboratory (NREL).

  4. A 2D Pseudodynamic Rupture Model Generator for Earthquakes on Geometrically Complex Faults

    E-Print Network [OSTI]

    Dunham, Eric M.

    A 2D Pseudodynamic Rupture Model Generator for Earthquakes on Geometrically Complex Faults complexity in the rupture process and resulting ground motion. We present a 2D kinematic rupture generator that emulates the strong dependence of earthquake source parameters on local fault geometry observed in dynamic

  5. Reducing Complexity of Rule Based Models via Meta Mining Lukasz A. Kurgan

    E-Print Network [OSTI]

    Kurgan, Lukasz

    Reducing Complexity of Rule Based Models via Meta Mining Lukasz A. Kurgan Department of Electrical that 50% complexity reduction can be achieved virtually without any loss of accuracy. Keywords: Rule, and for ease of explanation to non-technical decision makers

  6. On synchronous robotic networks - Part I: Models, tasks, and complexity

    E-Print Network [OSTI]

    Frazzoli, Emilio; Bullo, Francesco; Cortes, Jorge; Martinez, Sonia

    2007-01-01T23:59:59.000Z

    E. Frazzoli, “On synchronous robotic networks Part II: Timeto control design for mobile robotic networks. Application2007 On Synchronous Robotic Networks—Part I: Models, Tasks,

  7. A Decomposition Method for Synthesizing Complex Column Configurations Using Tray-by-Tray GDP Models

    E-Print Network [OSTI]

    Grossmann, Ignacio E.

    , complex distillation columns, initialization, discrete decision. Abstract This paper describes on the Reversible Distillation Sequence Model (RDSM) is proposed embedding all possible alternative designs using applied mathematical programming tools to rigorously solve the distillation design problem

  8. Critical enhancements of a dynamic traffic assignment model for highly congested, complex urban network

    E-Print Network [OSTI]

    Wei, Zheng, S.M. Massachusetts Institute of Technology

    2010-01-01T23:59:59.000Z

    To accurately replicate the highly congested traffic situation of a complex urban network, significant challenges are posed to current simulation-based dynamic traffic assignment (DTA) models. This thesis discusses these ...

  9. Description of the Earth system model of intermediate complexity LOVECLIM version 1.2

    E-Print Network [OSTI]

    Goosse, H.

    The main characteristics of the new version 1.2 of the three-dimensional Earth system model of intermediate complexity LOVECLIM are briefly described. LOVECLIM 1.2 includes representations of the atmosphere, the ocean and ...

  10. Modelling of wind turbine wakes in complex terrain using computational fluid dynamics 

    E-Print Network [OSTI]

    Makridis, Alexandros

    2012-06-25T23:59:59.000Z

    This thesis focuses on modelling of wind turbine wakes when they are affected by real complex terrain features, such as hills and forests, and also examines the effect of the rotational momentum imparted to the downstream ...

  11. Planning the Next Generation of Arctic Ecosystem Experiments

    SciTech Connect (OSTI)

    Hinzman, Larry D [International Arctic Research Center; Wilson, Cathy [Los Alamos National Laboratory (LANL)

    2011-01-01T23:59:59.000Z

    Climate Change Experiments in High-Latitude Ecosystems; Fairbanks, Alaska, 13-14 October 2010; A 2-day climate change workshop was held at the International Arctic Research Center, University of Alaska Fairbanks. The workshop, sponsored by Biological and Environmental Research, Office of Science, U.S. Department of Energy (DOE), was attended by 45 subject matter experts from universities, DOE national laboratories, and other federal and nongovernmental organizations. The workshop sought to engage the Arctic science community in planning for a proposed Next-Generation Ecosystem Experiments (NGEE-Arctic) project in Alaska (http:// ngee.ornl.gov/). The goal of this activity is to provide data, theory, and models to improve representations of high-latitude terrestrial processes in Earth system models. In particular, there is a need to better understand the processes by which warming may drive increased plant productivity and atmospheric carbon uptake and storage in biomass and soils, as well as those processes that may drive an increase in the release of methane (CH{sub 4}) and carbon dioxide (CO{sub 2}) through microbial decomposition of soil carbon stored in thawing permafrost. This understanding is required to quantify the important feedback mechanisms that define the role of terrestrial processes in regional and global climate.

  12. Immobilized metallodithiolate ligand supports for construction of bioinorganic model complexes

    E-Print Network [OSTI]

    Green, Kayla Nalynn

    2009-05-15T23:59:59.000Z

    as to protect the resin-bound models from O2 decomposition. As a model of the NiN2S2 ligand observed in the A-cluster of acetyl coA synthase, the CGC tripeptide was constructed on resins using Merrifield solid phase peptide synthesis and then metallated with Ni...

  13. Comparing Model-based and Design-based Structural Equation Modeling Approaches in Analyzing Complex Survey Data 

    E-Print Network [OSTI]

    Wu, Jiun-Yu

    2011-10-21T23:59:59.000Z

    Conventional statistical methods assuming data sampled under simple random sampling are inadequate for use on complex survey data with a multilevel structure and non-independent observations. In structural equation modeling ...

  14. Virtual enterprise model for the electronic components business in the Nuclear Weapons Complex

    SciTech Connect (OSTI)

    Ferguson, T.J.; Long, K.S.; Sayre, J.A. [Sandia National Labs., Albuquerque, NM (United States); Hull, A.L. [Sandia National Labs., Livermore, CA (United States); Carey, D.A.; Sim, J.R.; Smith, M.G. [Allied-Signal Aerospace Co., Kansas City, MO (United States). Kansas City Div.

    1994-08-01T23:59:59.000Z

    The electronic components business within the Nuclear Weapons Complex spans organizational and Department of Energy contractor boundaries. An assessment of the current processes indicates a need for fundamentally changing the way electronic components are developed, procured, and manufactured. A model is provided based on a virtual enterprise that recognizes distinctive competencies within the Nuclear Weapons Complex and at the vendors. The model incorporates changes that reduce component delivery cycle time and improve cost effectiveness while delivering components of the appropriate quality.

  15. 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 ...

  16. Springtime Arctic haze contributions of submicron organic particles from European and Asian combustion sources

    E-Print Network [OSTI]

    Kroll, Jesse

    The composition of Arctic aerosol, especially during the springtime Arctic haze, may play an important role in the radiative balance of the Arctic. The contribution of organic components to Arctic haze has only recently ...

  17. Evaluation of Arctic Broadband Surface Radiation Measurements

    SciTech Connect (OSTI)

    Matsui, N.; Long, Charles N.; Augustine, J. A.; Halliwell, D.; Uttal, Taneil; Longenecker, D.; Niebergale, J.; Wendell, J.; Albee, R.

    2012-02-24T23:59:59.000Z

    The Arctic is a challenging environment for making in-situ radiation measurements. A standard suite of radiation sensors is typically designed to measure the total, direct and diffuse components of incoming and outgoing broadband shortwave (SW) and broadband thermal infrared, or longwave (LW) radiation. Enhancements can include various sensors for measuring irradiance in various narrower bandwidths. Many solar radiation/thermal infrared flux sensors utilize protective glass domes and some are mounted on complex mechanical platforms (solar trackers) that rotate sensors and shading devices that track the sun. High quality measurements require striking a balance between locating sensors in a pristine undisturbed location free of artificial blockage (such as buildings and towers) and providing accessibility to allow operators to clean and maintain the instruments. Three significant sources of erroneous data include solar tracker malfunctions, rime/frost/snow deposition on the instruments and operational problems due to limited operator access in extreme weather conditions. In this study, a comparison is made between the global and component sum (direct [vertical component] + diffuse) shortwave measurements. The difference between these two quantities (that theoretically should be zero) is used to illustrate the magnitude and seasonality of radiation flux measurement problems. The problem of rime/frost/snow deposition is investigated in more detail for one case study utilizing both shortwave and longwave measurements. Solutions to these operational problems are proposed that utilize measurement redundancy, more sophisticated heating and ventilation strategies and a more systematic program of operational support and subsequent data quality protocols.

  18. Gaussian Process Model for Collision Dynamics of Complex Molecules

    E-Print Network [OSTI]

    Cui, Jie

    2015-01-01T23:59:59.000Z

    We show that a Gaussian Process model can be combined with a small number of scattering calculations to provide an accurate multi-dimensional dependence of scattering observables on the experimentally controllable parameters (such as the collision energy, temperature or external fields) as well as the potential energy surface parameters. This can be used for solving the inverse scattering problem, the prediction of collision properties of a specific molecular system based on the information for another molecule, the efficient calculation of thermally averaged observables and for reducing the error of the molecular dynamics calculations by averaging over the potential energy surface variations. We show that, trained by a combination of classical and quantum dynamics calculations, the model provides an accurate description of the scattering cross sections, even near scattering resonances. In this case, the classical calculations stabilize the model against uncertainties arising from wildly varying correlations ...

  19. Immobilized metallodithiolate ligand supports for construction of bioinorganic model complexes 

    E-Print Network [OSTI]

    Green, Kayla Nalynn

    2009-05-15T23:59:59.000Z

    + ........................................................................................ 109 Conclusions .................................................................................... 111 xi CHAPTER Page VII RESIN-BOUND MODELS OF THE [FeFe] HYDROGENASE ENZYME ACTIVE SITE AND REACTIVITY...) TentaGel beads incubated with Cu(OAc) 2 ?4H 2 O and (b) 20 equivalents of Cu(OAc) 2 ?4H 2 O mixed with ?-CysGlyCys..................................................................................... 108 VI-15 FTIR spectra of (a) ?-Cu...

  20. NREL's System Advisor Model Simplifies Complex Energy Analysis (Fact Sheet)

    SciTech Connect (OSTI)

    Not Available

    2015-01-01T23:59:59.000Z

    NREL has developed a tool -- the System Advisor Model (SAM) -- that can help decision makers analyze cost, performance, and financing of any size grid-connected solar, wind, or geothermal power project. Manufacturers, engineering and consulting firms, research and development firms, utilities, developers, venture capital firms, and international organizations use SAM for end-to-end analysis that helps determine whether and how to make investments in renewable energy projects.

  1. Real-time Rendering of Complex Vector Data on 3d Terrain Models

    E-Print Network [OSTI]

    Behnke, Sven

    Real-time Rendering of Complex Vector Data on 3d Terrain Models M. Schneider, M. Guthe, and R of buildings, streets and runway (from left to right). Abstract. In this paper we present a hybrid technique model. The first part of this hybrid technique is a texture-based approach that is especially suited

  2. AIP/123-QED Fuzzy structure theory modeling of sound-insulation layers in complex

    E-Print Network [OSTI]

    Paris-Sud XI, Université de

    AIP/123-QED Fuzzy structure theory modeling of sound-insulation layers in complex vibroacoustic France (Dated: September 11, 2008) Fuzzy structure theory for sound-insulation layers 1 hal-00684495 is proposed in developing an elas- toacoustic element useful to model sound-insulation layers for compu

  3. Local Genealogies in a Linear Mixed Model for Genome-Wide Association Mapping in Complex

    E-Print Network [OSTI]

    Schierup, Mikkel Heide

    Local Genealogies in a Linear Mixed Model for Genome-Wide Association Mapping in Complex Pedigreed fashion. Here, we present a complementary approach, called `GENMIX (genealogy based mixed model)' which combines advantages from two powerful GWAS methods: genealogy-based haplotype grouping and MMA. Subjects

  4. Arctic Ice Dynamics Joint Experiment (AIDJEX) assumptions revisited and found inadequate

    E-Print Network [OSTI]

    Sulsky, Deborah L.

    the Arctic Ice Dynamics Joint Experiment (AIDJEX) assumptions about pack ice behavior with an eye to modeling the behavior of pack ice. A model based on these assumptions is needed to represent the deformation and stress in pack ice on scales from 10 to 100 km, and would need to explicitly resolve discontinuities

  5. Greenland's Island Rule and the Arctic Ocean circulation by Terrence M. Joyce1,2

    E-Print Network [OSTI]

    Joyce, Terrence M.

    Greenland's Island Rule and the Arctic Ocean circulation by Terrence M. Joyce1,2 and Andrey made for the flow around Greenland. Godfrey's theory has been extended to permit inclusion of Bering Archipelago in the modeled flow west of Greenland. In both models, the forcing has been applied in a quasi

  6. Heavy Metal Contamination in the Taimyr Peninsula, Siberian Arctic

    SciTech Connect (OSTI)

    Allen-Gil, Susan M.; Ford, Jesse; Lasorsa, Brenda K.; Monetti, Matthew; Vlasova, Tamara; Landers, Dixon H.

    2003-01-01T23:59:59.000Z

    The Taimyr Peninsula is directly north of the world's largest heavy metal smelting complex (Norilsk, Russia). Despite this proximity, there has been little research to examine the extent of contamination of the Taimyr Peninsula. We analyzed heavy metal concentrations in lichen (Cetraria cucullata), moss (Hylocomium splendens), soils, lake sediment, freshwater fish (Salvelinus alpinus, Lota lota, and Coregonus spp.) and collared lemming (Dicrostonyx torquatus) from 13 sites between 30 and 300 km from Norilsk. Element concentrations were low in both C. cucullata and H. splendens, although concentrations of Al, Fe, Cu, Ni, and Pb were significantly higher than those in Arctic Alaska, probably due to natural differences in the geochemical environments. Inorganic surface soils had significantly higher concentrations of Cd, Zn, Pb, and Mg than inorganic soils at depth, although a lake sediment core from the eastern Taimyr Peninsula indicated no recent enrichment by atmospherically transported elements. Tissue concentrations of heavy metals in fish and lemming were not elevated relative to other Arctic sites. Our results show that the impact of the Norilsk smelting complex is primarily localized rather than regional, and does not extend northward beyond 100 km.

  7. Tuktoyaktuk : responsive strategies for a new Arctic urbanism

    E-Print Network [OSTI]

    Ritchot, Pamela (Pamela Rae)

    2011-01-01T23:59:59.000Z

    The Canadian Arctic is facing a set of compounding crises that will drastically impact the future of its coastal frontier. At a time when climate change is having a detrimental impact on the Arctic landscape, Northern ...

  8. Economic feasibility of shipping containers through the Arctic

    E-Print Network [OSTI]

    Pollock, Russell (Russell Clayton)

    2009-01-01T23:59:59.000Z

    As the Arctic ice cover continues to retreat, the possibility of regular transit through the Arctic becomes an increasing reality. Liner companies could take advantage of distance savings (up to 4000 nautical miles less ...

  9. Annotated bibliography of the Northwest Territories action on water component of the Arctic environmental strategy

    SciTech Connect (OSTI)

    Goodwin, R.

    1998-01-01T23:59:59.000Z

    Water-related research conducted under the 1991--97 Arctic Environmental Strategy resulted in the production of 215 publications listed in this bibliography. The main section sorts citations by author and then by title. All citations are annotated and are keyed to the database of the Arctic Science and Technology Information System (ASTIS). The bibliography has three indexes that refer back to the main section: Subject, geographic area, and title. Topics covered include Northwest Territories hydrology, environmental fate of contaminants, water quality, snow, the water cycle, modelling, and limnology.

  10. Long-term ice sheetclimate interactions under anthropogenic greenhouse forcing simulated with a complex Earth System Model

    E-Print Network [OSTI]

    Winguth, Arne

    with a complex Earth System Model Miren Vizcai´no Æ Uwe Mikolajewicz Æ Matthias Gro¨ger Æ Ernst Maier-Reimer Æ-millennia simulations have been performed with a complex Earth System Model (ESM) for different anthropogenic climate climate change Á Meridional overturning circulation Á Earth system modelling Á Sea level 1 Introduction

  11. The Arctic as a test case for an assessment of climate impacts on national security.

    SciTech Connect (OSTI)

    Taylor, Mark A.; Zak, Bernard Daniel; Backus, George A.; Ivey, Mark D.; Boslough, Mark Bruce Elrick

    2008-11-01T23:59:59.000Z

    The Arctic region is rapidly changing in a way that will affect the rest of the world. Parts of Alaska, western Canada, and Siberia are currently warming at twice the global rate. This warming trend is accelerating permafrost deterioration, coastal erosion, snow and ice loss, and other changes that are a direct consequence of climate change. Climatologists have long understood that changes in the Arctic would be faster and more intense than elsewhere on the planet, but the degree and speed of the changes were underestimated compared to recent observations. Policy makers have not yet had time to examine the latest evidence or appreciate the nature of the consequences. Thus, the abruptness and severity of an unfolding Arctic climate crisis has not been incorporated into long-range planning. The purpose of this report is to briefly review the physical basis for global climate change and Arctic amplification, summarize the ongoing observations, discuss the potential consequences, explain the need for an objective risk assessment, develop scenarios for future change, review existing modeling capabilities and the need for better regional models, and finally to make recommendations for Sandia's future role in preparing our leaders to deal with impacts of Arctic climate change on national security. Accurate and credible regional-scale climate models are still several years in the future, and those models are essential for estimating climate impacts around the globe. This study demonstrates how a scenario-based method may be used to give insights into climate impacts on a regional scale and possible mitigation. Because of our experience in the Arctic and widespread recognition of the Arctic's importance in the Earth climate system we chose the Arctic as a test case for an assessment of climate impacts on national security. Sandia can make a swift and significant contribution by applying modeling and simulation tools with internal collaborations as well as with outside organizations. Because changes in the Arctic environment are happening so rapidly, a successful program will be one that can adapt very quickly to new information as it becomes available, and can provide decision makers with projections on the 1-5 year time scale over which the most disruptive, high-consequence changes are likely to occur. The greatest short-term impact would be to initiate exploratory simulations to discover new emergent and robust phenomena associated with one or more of the following changing systems: Arctic hydrological cycle, sea ice extent, ocean and atmospheric circulation, permafrost deterioration, carbon mobilization, Greenland ice sheet stability, and coastal erosion. Sandia can also contribute to new technology solutions for improved observations in the Arctic, which is currently a data-sparse region. Sensitivity analyses have the potential to identify thresholds which would enable the collaborative development of 'early warning' sensor systems to seek predicted phenomena that might be precursory to major, high-consequence changes. Much of this work will require improved regional climate models and advanced computing capabilities. Socio-economic modeling tools can help define human and national security consequences. Formal uncertainty quantification must be an integral part of any results that emerge from this work.

  12. Lesson Summary Students will learn about the Arctic Beaufort Sea

    E-Print Network [OSTI]

    Mojzsis, Stephen J.

    Lesson Summary Students will learn about the Arctic Beaufort Sea and research the adaptations of people and animals in the arctic regions. They will also learn about how their actions can affect the Arctic and learn about the International Polar Year. Prior Knowledge & Skills · Research skills

  13. NGEE Arctic Webcam Photographs, Barrow Environmental Observatory, Barrow, Alaska

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

    Bob Busey; Larry Hinzman

    The NGEE Arctic Webcam (PTZ Camera) captures two views of seasonal transitions from its generally south-facing position on a tower located at the Barrow Environmental Observatory near Barrow, Alaska. Images are captured every 30 minutes. Historical images are available for download. The camera is operated by the U.S. DOE sponsored Next Generation Ecosystem Experiments - Arctic (NGEE Arctic) project.

  14. Simulating Arctic Climate Warmth and Icefield Retreat in the

    E-Print Network [OSTI]

    Ingólfsson, Ólafur

    , Devon, and Meighen ice caps in the Canadian Arctic, and possibly in Camp Century (northwest Greenland the entire western Arctic from 57-N to 85-N, including Greenland and smaller scale ice caps in Iceland Project members In the future, Arctic warming and the melting of polar glaciers will be considerable

  15. NGEE Arctic Webcam Photographs, Barrow Environmental Observatory, Barrow, Alaska

    SciTech Connect (OSTI)

    Bob Busey; Larry Hinzman

    2012-04-01T23:59:59.000Z

    The NGEE Arctic Webcam (PTZ Camera) captures two views of seasonal transitions from its generally south-facing position on a tower located at the Barrow Environmental Observatory near Barrow, Alaska. Images are captured every 30 minutes. Historical images are available for download. The camera is operated by the U.S. DOE sponsored Next Generation Ecosystem Experiments - Arctic (NGEE Arctic) project.

  16. Topology and current ribbons: A model for current, reconnection and flaring in a complex, evolving corona

    E-Print Network [OSTI]

    Longcope, Dana

    (MCC), for the build­up of magnetic energy in a three­dimensional corona of arbitrary geometry. The MCCTopology and current ribbons: A model for current, reconnection and flaring in a complex, evolving of energy from the Sun's chromosphere and corona. The build­up and release of energy in a flare has been

  17. Hybrid Car-Parrinello/Molecular Mechanics Modelling of Transition Metal Complexes: Structure, Dynamics and Reactivity

    E-Print Network [OSTI]

    Guidoni, Leonardo

    Hybrid Car-Parrinello/Molecular Mechanics Modelling of Transition Metal Complexes: Structure). We have recently developed a QM/MM extension of a Car-Parrinello scheme [5]. These hybrid Car functional theory embedded in a classical force field description. The power of such a combined Car

  18. New Logic Modeling Paradigms for Complex System Reliability and Risk Analysis

    E-Print Network [OSTI]

    Bernstein, Joseph B.

    New Logic Modeling Paradigms for Complex System Reliability and Risk Analysis Antoine Rauzy Chair ground ... is a mature technology ... is a great tool for decision making So, what's next? · More://www.lgi.ecp.fr/pmwiki.php/PagesPerso/ARauzy *Sponsored by SAFRAN group #12;Probabilistic Risk Assessment ... ... is now established on a solid scientific

  19. MICROELECTRONIC ENGINEERING RESEARCH CONFERENCE 2003 1 Low Complexity Gaussian Mixture Model-based Block

    E-Print Network [OSTI]

    is jointly Gaussian, hence Lloyd- Max non-uniform scalar quantisers are used in traditional block quan-based Block Quantisation of Images Stephen So and Kuldip K. Paliwal Abstract--In this paper, we present a low complexity version of Gaus- sian mixture model-based block quantisation for images. The latter coding method

  20. Inference-based Geometric Modeling for the Generation of Complex Cluttered Virtual Environments

    E-Print Network [OSTI]

    Biggers, Keith Edward

    2012-07-16T23:59:59.000Z

    that support the automatic construction of complex cluttered environments. The rst method we present is a surface reconstruction-based approach that is capable of reconstructing solid models from a point cloud capture of a cluttered environment. Our... III INFERENCE-BASED POINT CLOUD RECONSTRUCTION : 35 A. Overview . . . . . . . . . . . . . . . . . . . . . . . . . . . . 35 B. Algorithm Details . . . . . . . . . . . . . . . . . . . . . . . 37 1. Phase I: Setup...

  1. Quantitative Modeling of Complex Environments 1 Keith Decker and Victor Lesser

    E-Print Network [OSTI]

    Massachusetts at Amherst, University of

    an example model of cooperative problem solving in a distributed sensor network. 1 This paper, which extends resources of an agent or agents, as opposed to physical resources such as materials, machines, or men. Examples of such environments are distributed sensor networks, distributed design problems, complex

  2. Bayesian Emulation of Complex Multi-Output and Dynamic Computer Models

    E-Print Network [OSTI]

    Oakley, Jeremy

    Bayesian Emulation of Complex Multi-Output and Dynamic Computer Models Stefano Conti Anthony O the case). In particular, standard Monte Carlo-based methods of sensitivity analysis (extensively reviewed'Hagan, 2002), offering substantial efficiency gains over standard Monte Carlo-based meth- ods. These authors

  3. Coupling control and human factors in mathematical models of complex systems

    E-Print Network [OSTI]

    Melnik, Roderick

    dynamic systems Coupled field theory Systems science and cybernetics Markov chains and decision analysis process of the models for other complex dynamic systems. & 2008 Elsevier Ltd. All rights reserved. 1 systems between themselves and with dynamically changing environment, coupled effects and phenomena

  4. Status of Wind-Diesel Applications in Arctic Climates: Preprint

    SciTech Connect (OSTI)

    Baring-Gould, I.; Corbus, D.

    2007-12-01T23:59:59.000Z

    The rising cost of diesel fuel and the environmental regulation for its transportation, use, and storage, combined with the clear impacts of increased arctic temperatures, is driving remote communities to examine alternative methods of providing power. Over the past few years, wind energy has been increasingly used to reduce diesel fuel consumption, providing economic, environmental, and security benefits to the energy supply of communities from Alaska to Antarctica. This summary paper describes the current state of wind-diesel systems, reviews the operation of wind-diesel plants in cold climates, discusses current research activities pertaining to these systems, and addresses their technical and commercial challenges. System architectures, dispatch strategies, and operating experience from a variety of wind-diesel systems in Alaska will be reviewed. Specific focus will also be given to the control of power systems with large amounts of wind generation and the complexities of replacing diesel engine waste heat with excess wind energy, a key factor in assessing power plants for retrofit. A brief overview of steps for assessing the viability of retrofitting diesel power systems with wind technologies will also be provided. Because of the large number of isolated diesel minigrids, the market for adding wind to these systems is substantial, specifically in arctic climates and on islands that rely on diesel-only power generation.

  5. NAO influence on net sea ice production and exchanges in the Arctic region

    E-Print Network [OSTI]

    Hu, Aixue

    NAO influence on net sea ice production and exchanges in the Arctic region Aixue Hu, Claes Rooth and Rainer Bleck February 18, 2003 Abstract The variability of the net sea ice production and the sea ice circulation model. The wind driven divergence (or ice flux export) is the major factor controlling the net sea

  6. Modeling and Algorithmic Approaches to Constitutively-Complex, Micro-structured Fluids

    SciTech Connect (OSTI)

    Forest, Mark Gregory [University of North Carolina at Chapel Hill] [University of North Carolina at Chapel Hill

    2014-05-06T23:59:59.000Z

    The team for this Project made significant progress on modeling and algorithmic approaches to hydrodynamics of fluids with complex microstructure. Our advances are broken down into modeling and algorithmic approaches. In experiments a driven magnetic bead in a complex fluid accelerates out of the Stokes regime and settles into another apparent linear response regime. The modeling explains the take-off as a deformation of entanglements, and the longtime behavior is a nonlinear, far-from-equilibrium property. Furthermore, the model has predictive value, as we can tune microstructural properties relative to the magnetic force applied to the bead to exhibit all possible behaviors. Wave-theoretic probes of complex fluids have been extended in two significant directions, to small volumes and the nonlinear regime. Heterogeneous stress and strain features that lie beyond experimental capability were studied. It was shown that nonlinear penetration of boundary stress in confined viscoelastic fluids is not monotone, indicating the possibility of interlacing layers of linear and nonlinear behavior, and thus layers of variable viscosity. Models, algorithms, and codes were developed and simulations performed leading to phase diagrams of nanorod dispersion hydrodynamics in parallel shear cells and confined cavities representative of film and membrane processing conditions. Hydrodynamic codes for polymeric fluids are extended to include coupling between microscopic and macroscopic models, and to the strongly nonlinear regime.

  7. Pluton-dyke relationships in a Variscan granitic complex from AMS and gravity modelling. Inception of the extensional tectonics

    E-Print Network [OSTI]

    Paris-Sud XI, Université de

    Pluton-dyke relationships in a Variscan granitic complex from AMS and gravity modelling. Inception Orléans cedex 2, France Abstract The Carnac granitic Complex (South Armorican Domain, Western France zones in the western part of the complex, interpreted as the pluton feeder zones. The internal granitic

  8. Age characteristics in a multidecadal Arctic sea ice simulation

    SciTech Connect (OSTI)

    Hunke, Elizabeth C [Los Alamos National Laboratory; Bitz, Cecllia M [UNIV. OF WASHINGTON

    2008-01-01T23:59:59.000Z

    Results from adding a tracer for age of sea ice to a sophisticated sea ice model that is widely used for climate studies are presented. The consistent simulation of ice age, dynamics, and thermodynamics in the model shows explicitly that the loss of Arctic perennial ice has accelerated in the past three decades, as has been seen in satellite-derived observations. Our model shows that the September ice age average across the Northern Hemisphere varies from about 5 to 8 years, and the ice is much younger (about 2--3 years) in late winter because of the expansion of first-year ice. We find seasonal ice on average comprises about 5% of the total ice area in September, but as much as 1.34 x 10{sup 6} km{sup 2} survives in some years. Our simulated ice age in the late 1980s and early 1990s declined markedly in agreement with other studies. After this period of decline, the ice age began to recover, but in the final years of the simulation very little young ice remains after the melt season, a strong indication that the age of the pack will again decline in the future as older ice classes fail to be replenished. The Arctic ice pack has fluctuated between older and younger ice types over the past 30 years, while ice area, thickness, and volume all declined over the same period, with an apparent acceleration in the last decade.

  9. Simulation of complex glazing products; from optical data measurements to model based predictive controls

    SciTech Connect (OSTI)

    Kohler, Christian

    2012-08-01T23:59:59.000Z

    Complex glazing systems such as venetian blinds, fritted glass and woven shades require more detailed optical and thermal input data for their components than specular non light-redirecting glazing systems. Various methods for measuring these data sets are described in this paper. These data sets are used in multiple simulation tools to model the thermal and optical properties of complex glazing systems. The output from these tools can be used to generate simplified rating values or as an input to other simulation tools such as whole building annual energy programs, or lighting analysis tools. I also describe some of the challenges of creating a rating system for these products and which factors affect this rating. A potential future direction of simulation and building operations is model based predictive controls, where detailed computer models are run in real-time, receiving data for an actual building and providing control input to building elements such as shades.

  10. Final Technical Report for Project "Improving the Simulation of Arctic Clouds in CCSM3"

    SciTech Connect (OSTI)

    Stephen J. Vavrus

    2008-11-15T23:59:59.000Z

    This project has focused on the simulation of Arctic clouds in CCSM3 and how the modeled cloud amount (and climate) can be improved substantially by altering the parameterized low cloud fraction. The new formula, dubbed 'freeezedry', alleviates the bias of excessive low clouds during polar winter by reducing the cloud amount under very dry conditions. During winter, freezedry decreases the low cloud amount over the coldest regions in high latitudes by over 50% locally and more than 30% averaged across the Arctic (Fig. 1). The cloud reduction causes an Arctic-wide drop of 15 W m{sup -2} in surface cloud radiative forcing (CRF) during winter and about a 50% decrease in mean annual Arctic CRF. Consequently, wintertime surface temperatures fall by up to 4 K on land and 2-8 K over the Arctic Ocean, thus significantly reducing the model's pronounced warm bias (Fig. 1). While improving the polar climate simulation in CCSM3, freezedry has virtually no influence outside of very cold regions (Fig. 2) or during summer (Fig. 3), which are space and time domains that were not targeted. Furthermore, the simplicity of this parameterization allows it to be readily incorporated into other GCMs, many of which also suffer from excessive wintertime polar cloudiness, based on the results from the CMIP3 archive (Vavrus et al., 2008). Freezedry also affects CCSM3's sensitivity to greenhouse forcing. In a transient-CO{sub 2} experiment, the model version with freezedry warms up to 20% less in the North Polar and South Polar regions (1.5 K and 0.5 K smaller warming, respectively) (Fig. 4). Paradoxically, the muted high-latitude response occurs despite a much larger increase in cloud amount with freezedry during non-summer months (when clouds warm the surface), apparently because of the colder modern reference climate. These results of the freezedry parameterization have recently been published (Vavrus and D. Waliser, 2008: An improved parameterization for simulating Arctic cloud amount in the CCSM3 climate model. J. Climate, 21, 5673-5687.). The article also provides a novel synthesis of surface- and satellite-based Arctic cloud observations that show how much the new freezedry parameterization improves the simulated cloud amount in high latitudes (Fig. 3). Freezedry has been incorporated into the CCSM3.5 version, in which it successfully limits the excessive polar clouds, and may be used in CCSM4. Material from this work is also appearing in a synthesis article on future Arctic cloud changes (Vavrus, D. Waliser, J. Francis, and A. Schweiger, 'Simulations of 20th and 21st century Arctic cloud amount in the global climate models assessed in the IPCC AR4', accepted in Climate Dynamics) and was used in a collaborative paper on Arctic cloud-sea ice coupling (Schweiger, A., R. Lindsay, S. Vavrus, and J. Francis, 2008: Relationships between Arctic sea ice and clouds during autumn. J. Climate, 21, 4799-4810.). This research was presented at the 2007 CCSM Annual Workshop, as well as the CCSM's 2007 Atmospheric Model Working Group and Polar Working Group Meetings. The findings were also shown at the 2007 Climate Change Prediction Program's Science Team Meeting. In addition, I served as an instructor at the International Arctic Research Center's (IARC) Summer School on Arctic Climate Modeling in Fairbanks this summer, where I presented on the challenges and techniques used in simulating polar clouds. I also contributed to the development of a new Arctic System Model by attending a workshop in Colorado this summer on this fledgling project. Finally, an outreach activity for the general public has been the development of an interactive web site (model/visualization/ipcc/>) that displays Arctic cloud amount in the CMIP3 climate model archive under present and future scenarios. This site allows users to make polar and global maps of a variety of climate variables to investigate the individual and ensemble-mean GCM response to greenhouse warming and the extent to which models adequately represent Arctic clouds in the modern clima

  11. Generative model selection using a scalable and size-independent complex network classifier

    SciTech Connect (OSTI)

    Motallebi, Sadegh, E-mail: motallebi@ce.sharif.edu; Aliakbary, Sadegh, E-mail: aliakbary@ce.sharif.edu; Habibi, Jafar, E-mail: jhabibi@sharif.edu [Department of Computer Engineering, Sharif University of Technology, Tehran (Iran, Islamic Republic of)] [Department of Computer Engineering, Sharif University of Technology, Tehran (Iran, Islamic Republic of)

    2013-12-15T23:59:59.000Z

    Real networks exhibit nontrivial topological features, such as heavy-tailed degree distribution, high clustering, and small-worldness. Researchers have developed several generative models for synthesizing artificial networks that are structurally similar to real networks. An important research problem is to identify the generative model that best fits to a target network. In this paper, we investigate this problem and our goal is to select the model that is able to generate graphs similar to a given network instance. By the means of generating synthetic networks with seven outstanding generative models, we have utilized machine learning methods to develop a decision tree for model selection. Our proposed method, which is named “Generative Model Selection for Complex Networks,” outperforms existing methods with respect to accuracy, scalability, and size-independence.

  12. Arctic Energy Summit | Department of Energy

    Energy Savers [EERE]

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page onYou are now leaving Energy.gov You are now leaving Energy.gov You are being directed off Energy.gov. Are you0 ARRA NewslettersPartnership of theArctic Energy Summit Arctic Energy Summit

  13. QMU as an approach to strengthening the predictive capabilities of complex models.

    SciTech Connect (OSTI)

    Gray, Genetha Anne; Boggs, Paul T.; Grace, Matthew D.

    2010-09-01T23:59:59.000Z

    Complex systems are made up of multiple interdependent parts, and the behavior of the entire system cannot always be directly inferred from the behavior of the individual parts. They are nonlinear and system responses are not necessarily additive. Examples of complex systems include energy, cyber and telecommunication infrastructures, human and animal social structures, and biological structures such as cells. To meet the goals of infrastructure development, maintenance, and protection for cyber-related complex systems, novel modeling and simulation technology is needed. Sandia has shown success using M&S in the nuclear weapons (NW) program. However, complex systems represent a significant challenge and relative departure from the classical M&S exercises, and many of the scientific and mathematical M&S processes must be re-envisioned. Specifically, in the NW program, requirements and acceptable margins for performance, resilience, and security are well-defined and given quantitatively from the start. The Quantification of Margins and Uncertainties (QMU) process helps to assess whether or not these safety, reliability and performance requirements have been met after a system has been developed. In this sense, QMU is used as a sort of check that requirements have been met once the development process is completed. In contrast, performance requirements and margins may not have been defined a priori for many complex systems, (i.e. the Internet, electrical distribution grids, etc.), particularly not in quantitative terms. This project addresses this fundamental difference by investigating the use of QMU at the start of the design process for complex systems. Three major tasks were completed. First, the characteristics of the cyber infrastructure problem were collected and considered in the context of QMU-based tools. Second, UQ methodologies for the quantification of model discrepancies were considered in the context of statistical models of cyber activity. Third, Bayesian methods for optimal testing in the QMU framework were developed. This completion of this project represent an increased understanding of how to apply and use the QMU process as a means for improving model predictions of the behavior of complex systems. 4

  14. Arctic Energy Technology Development Laboratory

    SciTech Connect (OSTI)

    Sukumar Bandopadhyay; Charles Chamberlin; Robert Chaney; Gang Chen; Godwin Chukwu; James Clough; Steve Colt; Anthony Covescek; Robert Crosby; Abhijit Dandekar; Paul Decker; Brandon Galloway; Rajive Ganguli; Catherine Hanks; Rich Haut; Kristie Hilton; Larry Hinzman; Gwen Holdman; Kristie Holland; Robert Hunter; Ron Johnson; Thomas Johnson; Doug Kame; Mikhail Kaneveskly; Tristan Kenny; Santanu Khataniar; Abhijeet Kulkami; Peter Lehman; Mary Beth Leigh; Jenn-Tai Liang; Michael Lilly; Chuen-Sen Lin; Paul Martin; Pete McGrail; Dan Miller; Debasmita Misra; Nagendra Nagabhushana; David Ogbe; Amanda Osborne; Antoinette Owen; Sharish Patil; Rocky Reifenstuhl; Doug Reynolds; Eric Robertson; Todd Schaef; Jack Schmid; Yuri Shur; Arion Tussing; Jack Walker; Katey Walter; Shannon Watson; Daniel White; Gregory White; Mark White; Richard Wies; Tom Williams; Dennis Witmer; Craig Wollard; Tao Zhu

    2008-12-31T23:59:59.000Z

    The Arctic Energy Technology Development Laboratory was created by the University of Alaska Fairbanks in response to a congressionally mandated funding opportunity through the U.S. Department of Energy (DOE), specifically to encourage research partnerships between the university, the Alaskan energy industry, and the DOE. The enabling legislation permitted research in a broad variety of topics particularly of interest to Alaska, including providing more efficient and economical electrical power generation in rural villages, as well as research in coal, oil, and gas. The contract was managed as a cooperative research agreement, with active project monitoring and management from the DOE. In the eight years of this partnership, approximately 30 projects were funded and completed. These projects, which were selected using an industry panel of Alaskan energy industry engineers and managers, cover a wide range of topics, such as diesel engine efficiency, fuel cells, coal combustion, methane gas hydrates, heavy oil recovery, and water issues associated with ice road construction in the oil fields of the North Slope. Each project was managed as a separate DOE contract, and the final technical report for each completed project is included with this final report. The intent of this process was to address the energy research needs of Alaska and to develop research capability at the university. As such, the intent from the beginning of this process was to encourage development of partnerships and skills that would permit a transition to direct competitive funding opportunities managed from funding sources. This project has succeeded at both the individual project level and at the institutional development level, as many of the researchers at the university are currently submitting proposals to funding agencies, with some success.

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

    SciTech Connect (OSTI)

    Eric T. DeWeaver

    2010-02-17T23:59:59.000Z

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

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

    SciTech Connect (OSTI)

    Eric T. DeWeaver

    2010-01-19T23:59:59.000Z

    This is the final report for DOE grant DE-FG02-07ER64434 to Eric DeWeaver at the University of Wisconsin-Madison. 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. 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 furthe 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 to the extent that research targets of opportunity present themselves. Research performed under the grant falls into five main research areas: 1) a study of data assimilation using an ensemble filter with the atmospheric circulation model of the National Center for Atmospheric Research, in which both conventional observations and observations of the refraction of radio waves from GPS satellites were used to constrain the atmospheric state of the model; 2) research on the likely future status of polar bears, in which climate model simluations were used to assess the effectiveness of climate change mitigation efforts in preserving the habitat of polar bears, now considered a threatened species under global warming; 3) as assessment of the credibility of Arctic sea ice thickness simulations from climate models; 4) An examination of the persistence and reemergence of Northern Hemisphere sea ice area anomalies in climate model simulations and in observations; 5) An examination of the roles played by changes in net radiation and surface relative humidity in determine the response of the hydrological cycle to global warming.

  17. Transport of anthropogenic and biomass burning aerosols from Europe to the Arctic during spring 2008

    SciTech Connect (OSTI)

    Marelle, L.; Raut, Jean-Christophe; Thomas, J. L.; Law, K. S.; Quennehen, Boris; Ancellet, G.; Pelon, J.; Schwarzenboeck, A.; Fast, Jerome D.

    2015-01-01T23:59:59.000Z

    During the POLARCAT-France airborne campaign in April 2008, pollution originating from anthropogenic and biomass burning emissions was measured in the European Arctic. We compare these aircraft measurements with simulations using the WRF-Chem model to investigate model representation of aerosols transported from Europe to the Arctic. Modeled PM2.5 is evaluated using EMEP measurements in source regions and POLARCAT aircraft measurements in the Scandinavian Arctic, showing a good agreement, although the model overestimates nitrate and underestimates organic carbon in source regions. Using WRF-Chem in combination with the Lagrangian model FLEXPART-WRF, we find that during the campaign the research aircraft sampled two different types of European plumes: mixed anthropogenic and fire plumes from eastern Europe and Russia transported below 2 km, and anthropogenic plumes from central Europe uplifted by warm conveyor belt circulations to 5–6 km. Both modeled plume types had significant wet scavenging (> 50% PM10) during transport. Modeled aerosol vertical distributions and optical properties below the aircraft are evaluated in the Arctic using airborne LIDAR measurements. Evaluating the regional impacts in the Arctic of this event in terms of aerosol vertical structure, we find that during the 4 day presence of these aerosols in the lower European Arctic (< 75° N), biomass burning emissions have the strongest influence on concentrations between 2.5 and 3 km altitudes, while European anthropogenic emissions influence aerosols at both lower (~1.5 km) and higher altitudes (~4.5 km). As a proportion of PM2.5, modeled black carbon and SO4= concentrations are more enhanced near the surface. The European plumes sampled during POLARCAT-France were transported over the region of springtime snow cover in Northern Scandinavia, where they had a significant local atmospheric warming effect. We find that, during this transport event, the average modeled top of atmosphere (TOA) shortwave direct and semi-direct radiative effect (DSRE) north of 60° N over snow and ice-covered surfaces reaches +0.58 W m?², peaking at +3.3 W m?² at noon over Scandinavia and Finland.

  18. Circumpolar Arctic Tundra Vegetation Change Is Linked

    E-Print Network [OSTI]

    Bhatt, Uma

    of Plant Biology, Michigan State University, East Lansing, Michigan Received 7 December 2009; accepted 4Circumpolar Arctic Tundra Vegetation Change Is Linked to Sea Ice Decline Uma S. Bhatt*,1 Donald A Institute, and Department of Atmospheric Sciences, University of Alaska Fairbanks, Fairbanks, Alaska

  19. Computationally Efficient Use of Derivatives in Emulation of Complex Computational Models

    SciTech Connect (OSTI)

    Williams, Brian J. [Los Alamos National Laboratory; Marcy, Peter W. [University of Wyoming

    2012-06-07T23:59:59.000Z

    We will investigate the use of derivative information in complex computer model emulation when the correlation function is of the compactly supported Bohman class. To this end, a Gaussian process model similar to that used by Kaufman et al. (2011) is extended to a situation where first partial derivatives in each dimension are calculated at each input site (i.e. using gradients). A simulation study in the ten-dimensional case is conducted to assess the utility of the Bohman correlation function against strictly positive correlation functions when a high degree of sparsity is induced.

  20. Determining Wind Turbine Gearbox Model Complexity Using Measurement Validation and Cost Comparison: Preprint

    SciTech Connect (OSTI)

    LaCava, W.; Xing, Y.; Guo, Y.; Moan, T.

    2012-04-01T23:59:59.000Z

    The Gearbox Reliability Collaborative (GRC) has conducted extensive field and dynamometer test campaigns on two heavily instrumented wind turbine gearboxes. In this paper, data from the planetary stage is used to evaluate the accuracy and computation time of numerical models of the gearbox. First, planet-bearing load and motion data is analyzed to characterize planetary stage behavior in different environments and to derive requirements for gearbox models and life calculations. Second, a set of models are constructed that represent different levels of fidelity. Simulations of the test conditions are compared to the test data and the computational cost of the models are compared. The test data suggests that the planet-bearing life calculations should be made separately for each bearing on a row due to unequal load distribution. It also shows that tilting of the gear axes is related to planet load share. The modeling study concluded that fully flexible models were needed to predict planet-bearing loading in some cases, although less complex models were able to achieve good correlation in the field-loading case. Significant differences in planet load share were found in simulation and were dependent on the scope of the model and the bearing stiffness model used.

  1. APPLICATION OF CARBOHYDRATES AND PHENOLS AS BIOMARKERS TO STUDY DISSOLVED ORGANIC MATTER RESERVOIRS IN ARCTIC RIVERS.

    E-Print Network [OSTI]

    McMahon, Rachel

    2014-01-22T23:59:59.000Z

    Arctic rivers are the dominant pathways for the transport of terrestrial dissolved organic carbon to the Arctic Ocean, but knowledge of sources, transformations and transfer of organic carbon and nitrogen in Arctic river watersheds is extremely...

  2. U.S. Geological Survery Oil and Gas Resource Assessment of the Russian Arctic

    SciTech Connect (OSTI)

    Donald Gautier; Timothy Klett

    2008-12-31T23:59:59.000Z

    The U.S. Geological Survey (USGS) recently completed a study of undiscovered petroleum resources in the Russian Arctic as a part of its Circum-Arctic Resource Appraisal (CARA), which comprised three broad areas of work: geological mapping, basin analysis, and quantitative assessment. The CARA was a probabilistic, geologically based study that used existing USGS methodology, modified somewhat for the circumstances of the Arctic. New map compilation was used to identify assessment units. The CARA relied heavily on geological analysis and analog modeling, with numerical input consisting of lognormal distributions of sizes and numbers of undiscovered accumulations. Probabilistic results for individual assessment units were statistically aggregated, taking geological dependencies into account. The U.S. Department of Energy (DOE) funds were used to support the purchase of crucial seismic data collected in the Barents Sea, East Siberian Sea, and Chukchi Sea for use by USGS in its assessment of the Russian Arctic. DOE funds were also used to purchase a commercial study, which interpreted seismic data from the northern Kara Sea, and for geographic information system (GIS) support of USGS mapping of geological features, province boundaries, total petroleum systems, and assessment units used in the USGS assessment.

  3. Evaluating Model Parameterizations of Arctic Processes

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

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative1 First Use of Energy for All Purposes (Fuel and Nonfuel), 2002; Level: National5Sales for4,645U.S. DOEThe Bonneville Power AdministrationField8,Dist. Category UC-l 1, 13Evacuation Emergency Informationthe Effect

  4. E-Print Network 3.0 - arctic cooling silentium Sample Search...

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

    12;Abstract The Arctic is melting ...fast. 12;IMPACTS OF A WARMING ARCTIC... 's Greenhouse Effect Thesur face cools by radiating heat energyupward. ... Source: Zender, Charles -...

  5. MODELING THE GENERATION AND DISSOCIATION OF THE BORON-OXYGEN COMPLEX IN B-DOPED CZ-SI

    E-Print Network [OSTI]

    MODELING THE GENERATION AND DISSOCIATION OF THE BORON-OXYGEN COMPLEX IN B-DOPED CZ-SI Bianca Lim Emmerthal, Germany ABSTRACT We demonstrate that the boron-oxygen (BsO2i) re- combination center responsible of this complex with the oxygen dimer O2i into XO2i, thereby reducing the concen- tration of unbound O2i

  6. Relative importance of multiple factors on terrestrial loading of DOC to Arctic river networks

    SciTech Connect (OSTI)

    Kicklighter, David W. [Ecosystem Center, The] [Ecosystem Center, The; Hayes, Daniel J [ORNL] [ORNL; Mcclelland, James W [University of Texas] [University of Texas; Peterson, Bruce [Marine Biological Laboratory] [Marine Biological Laboratory; Mcguire, David [University of Alaska] [University of Alaska; Melillo, Jerry [Marine Biological Laboratory] [Marine Biological Laboratory

    2014-01-01T23:59:59.000Z

    Terrestrial carbon dynamics influence the contribution of dissolved organic carbon (DOC) to river networks in addition to controlling carbon fluxes between the land surface and the atmosphere. In this study, we use a biogeochemical process model to simulate the lateral transfer of DOC from land to the Arctic Ocean via riverine transport. We estimate that the pan-arctic watershed has contributed, on average, 32 Tg C/yr of DOC to the Arctic Ocean over the 20th century with most coming from the extensive area of boreal deciduous needle-leaved forests and forested wetlands in Eurasian watersheds. We also estimate that the rate of terrestrial DOC loading has been increasing by 0.037 Tg C/yr2 over the 20th century primarily as a result of increases in air temperatures and precipitation. These increases have been partially compensated by decreases in terrestrial DOC loading caused by wildfires. Other environmental factors (CO2 fertilization, ozone pollution, atmospheric nitrogen deposition, timber harvest, agriculture) are estimated to have relatively small effects on terrestrial DOC loading to arctic rivers. The effects of the various environmental factors on terrestrial carbon dynamics have both compensated and enhanced concurrent effects on hydrology to influence terrestrial DOC loading. Future increases in riverine DOC concentrations and export may occur from warming-induced increases in terrestrial DOC production associated with enhanced microbial metabolism and the exposure of additional organic matter from permafrost degradation along with decreases in water yield associated with warming-induced increases in evapotranspiration. Improvements in simulating terrestrial DOC loading to pan-arctic rivers in the future will require better information on the spatial distribution of precipitation and its temporal trends, carbon dynamics of larch-dominated ecosystems in eastern Siberia, and the role of industrial organic effluents on carbon budgets of rivers in western Russia.

  7. arctic endemic brown: Topics by E-print Network

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

    Geosciences Websites Summary: 12;4 C. Duguay, Interdisciplinary Centre on Climate Change & Department of Geography-Harte, Institute of Arctic Biology, University of Alaska...

  8. arctic populations differential: Topics by E-print Network

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

    climate connection, total solar irradiance, Atlantic meridional overturning circulation, climate variability. Willie W. -h. Soon 2009-01-01 168 Arctic catastrophes in an idealized...

  9. arctic petroleum operators: Topics by E-print Network

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

    operations waste water injection and disposal wells, geothermal resource development, and EORCO2 Southern California, University of 66 A Holocene record of changing Arctic Ocean...

  10. arctic region baltic: Topics by E-print Network

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

    look at the higher trophic re-lationships of the crustacean zooplankton of arctic polygon depression ponds, hoping not only to discover which species were predaceous, but to...

  11. arctic study area: Topics by E-print Network

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

    Explosion At The Polar Arctic Sunrise Physics (arXiv) Summary: We attempt is to provide accumulated evidence and qualitative understanding of the associated atmospheric phenomena...

  12. arctic polar vortex: Topics by E-print Network

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

    Explosion At The Polar Arctic Sunrise Physics (arXiv) Summary: We attempt is to provide accumulated evidence and qualitative understanding of the associated atmospheric phenomena...

  13. Potential Oil Production from the Coastal Plain of the Arctic...

    U.S. Energy Information Administration (EIA) Indexed Site

    Slope ANWR: Arctic National Wildlife Refuge BBbls: billion barrels Bbls: barrels Daily Petroleum Production Rate: The amount of petroleum extracted per day from a well, group of...

  14. arctic crude oil: Topics by E-print Network

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

    water to form an emulsion that often looks like chocolate pudding. This emulsion 89 Lesson Plan Arctic Biome Geosciences Websites Summary: -class instruction and small group...

  15. Potential Oil Production from the Coastal Plain of the Arctic...

    Gasoline and Diesel Fuel Update (EIA)

    Potential Oil Production from the Coastal Plain of the Arctic National Wildlife Refuge: Updated Assessment Executive Summary This Service Report, Potential Oil Production from the...

  16. Potential Oil Production from the Coastal Plain of the Arctic...

    U.S. Energy Information Administration (EIA) Indexed Site

    Potential Oil Production from the Coastal Plain of the Arctic National Wildlife Refuge: Updated Assessment 2. Analysis Discussion Resource Assessment The USGS most recent...

  17. Potential Oil Production from the Coastal Plain of the Arctic...

    U.S. Energy Information Administration (EIA) Indexed Site

    Potential Oil Production from the Coastal Plain of the Arctic National Wildlife Refuge: Updated Assessment References Energy Information Administration, Annual Energy Outlook 2000,...

  18. arctic ocean sediments: Topics by E-print Network

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

    Is the central Arctic Ocean a sediment starved basin, University of Bergen, Norway d Byrd Polar Research Center, Ohio State University, USA Abstract Numerous short...

  19. arctic marine environment: Topics by E-print Network

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

    of Technology, Cambridge, MA Patrikalakis, Nicholas M. 4 UiT The Arctic University of Norway Fakultet for biovitenskap, fiskeri og konomi -Inst. for arktisk og marin biologi...

  20. arctic ocean sediment: Topics by E-print Network

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

    Is the central Arctic Ocean a sediment starved basin, University of Bergen, Norway d Byrd Polar Research Center, Ohio State University, USA Abstract Numerous short...

  1. arctic flora origins: Topics by E-print Network

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

    combustion of fossil fuels and biomass, may have a severe impact on the sensitive Arctic climate, possibly altering the temperature profile, cloud temperature and amount, the...

  2. arctic lake correlate: Topics by E-print Network

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

    Alaskan arctic lake Sally MacIntyre,a,b* Geosciences Websites Summary: . In summers with cold surface temperatures, the surface energy fluxes which induce mixing by heat loss...

  3. arctic marine ecosystem: Topics by E-print Network

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

    the Bamboung marine protected area social-ecosystem. Key words Social-ecological system, climate Paris-Sud XI, Universit de 6 Perfluoroalkyl Contaminants in an Arctic Marine...

  4. alaskan arctic tundra: Topics by E-print Network

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

    Alaskan arctic lake Sally MacIntyre,a,b* Geosciences Websites Summary: . In summers with cold surface temperatures, the surface energy fluxes which induce mixing by heat loss...

  5. arctic charr salvelinus: Topics by E-print Network

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

    have raised concern over potential responses of Arctic charr, Salvelinus alpinus, a cold-adapted freshwateranadromous fish species in (more) Sinnatamby, Ramila Niloshini...

  6. arctic char salvelinus: Topics by E-print Network

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

    have raised concern over potential responses of Arctic charr, Salvelinus alpinus, a cold-adapted freshwateranadromous fish species in (more) Sinnatamby, Ramila Niloshini...

  7. arctic research station: Topics by E-print Network

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

    The Rocky Mountain Research Sta- tion is one of five 19 Z .Atmospheric Research 51 1999 4575 Cloud resolving simulations of Arctic stratus Geosciences Websites Summary: Z...

  8. arctic terns sterna: Topics by E-print Network

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

    together. Amie L. Black; Antony W. Diamond 2 Duffy et al.: Arctic Tern migration over Patagonia 155 Marine Ornithology 41: 155159 (2013) Environmental Sciences and Ecology Websites...

  9. arctic climate system: Topics by E-print Network

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

    Alaskan arctic lake Sally MacIntyre,a,b* Geosciences Websites Summary: . In summers with cold surface temperatures, the surface energy fluxes which induce mixing by heat loss...

  10. alaskan arctic coastal: Topics by E-print Network

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

    Alaskan arctic lake Sally MacIntyre,a,b* Geosciences Websites Summary: . In summers with cold surface temperatures, the surface energy fluxes which induce mixing by heat loss...

  11. arctic tundra vegetation: Topics by E-print Network

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

    of woody vegetation in arctic tundra? Biology and Medicine Websites Summary: 33124, USA. Global climate warming is projected to promote the increase of woody plants, especially of...

  12. arctas arctic research: Topics by E-print Network

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

    Arctic. It often serves as the measuring stick for global climate change. It is where warming has been strongest in the past century, Environmental Sciences and Ecology Websites...

  13. ALUMINUM DISTRIBUTIONSIN THE EURASIAN BASIN OF THE ARCTIC OCEAN

    E-Print Network [OSTI]

    Luther, Douglas S.

    ALUMINUM DISTRIBUTIONSIN THE EURASIAN BASIN OF THE ARCTIC OCEAN A THESISSUBMITTEDTO THE GRADUATE Section(1994)cruiseswere analyzed for their aluminum (Al) content; these two data setswere then combined

  14. arctic marine food: Topics by E-print Network

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

    Next Page Last Page Topic Index 1 Perfluoroalkyl Contaminants in an Arctic Marine Food Web: Trophic Environmental Sciences and Ecology Websites Summary: Perfluoroalkyl...

  15. The Evolutionary Design Model (EDM) for the design of complex engineered systems : Masdar City as a case study

    E-Print Network [OSTI]

    Alfaris, Anas (Anas Faris)

    2009-01-01T23:59:59.000Z

    This thesis develops a framework for constructing an Evolutionary Design Model (EDM) that would enhance the design of complex systems through an efficient process. The framework proposed is generic and suggests a group of ...

  16. Numerical simulation of swirling flow in complex hydroturbine draft tube using unsteady statistical turbulence models

    SciTech Connect (OSTI)

    Paik, Joongcheol [University of Minnesota; Sotiropoulos, Fotis [University of Minnesota; Sale, Michael J [ORNL

    2005-06-01T23:59:59.000Z

    A numerical method is developed for carrying out unsteady Reynolds-averaged Navier-Stokes (URANS) simulations and detached-eddy simulations (DESs) in complex 3D geometries. The method is applied to simulate incompressible swirling flow in a typical hydroturbine draft tube, which consists of a strongly curved 90 degree elbow and two piers. The governing equations are solved with a second-order-accurate, finite-volume, dual-time-stepping artificial compressibility approach for a Reynolds number of 1.1 million on a mesh with 1.8 million nodes. The geometrical complexities of the draft tube are handled using domain decomposition with overset (chimera) grids. Numerical simulations show that unsteady statistical turbulence models can capture very complex 3D flow phenomena dominated by geometry-induced, large-scale instabilities and unsteady coherent structures such as the onset of vortex breakdown and the formation of the unsteady rope vortex downstream of the turbine runner. Both URANS and DES appear to yield the general shape and magnitude of mean velocity profiles in reasonable agreement with measurements. Significant discrepancies among the DES and URANS predictions of the turbulence statistics are also observed in the straight downstream diffuser.

  17. Intercomparison and Evaluation of Global Aerosol Microphysical Properties among AeroCom Models of a Range of Complexity

    SciTech Connect (OSTI)

    Mann, G. W.; Carslaw, K. S.; Reddington, C. L.; Pringle, K. J.; Schulz, M.; Asmi, A.; Spracklen, D. V.; Ridley, D. A.; Woodhouse, M. T.; Lee, L. A.; Zhang, Kai; Ghan, Steven J.; Easter, Richard C.; Liu, Xiaohong; Stier, P.; Lee, Y. H.; Adams, P. J.; Tost, H.; Lelieveld, J.; Bauer, S.; Tsigaridis, Kostas; van Noije, T.; Strunk, A.; Vignati, E.; Bellouin, N.; Dalvi, M.; Johnson, C. E.; Bergman, T.; Kokkola, H.; Von Salzen, Knut; Yu, Fangqun; Luo, Gan; Petzold, A.; Heintzenberg, J.; Clarke, A. D.; Ogren, J. A.; Gras, J.; Baltensperger, Urs; Kaminski, U.; Jennings, S. G.; O'Dowd, C. D.; Harrison, R. M.; Beddows, D. C.; Kulmala, M.; Viisanen, Y.; Ulevicius, V.; Mihalopoulos, Nikos; Zdimal, V.; Fiebig, M.; Hansson, H. C.; Swietlicki, E.; Henzing, J. S.

    2014-05-13T23:59:59.000Z

    Many of the next generation of global climate models will include aerosol schemes which explicitly simulate the microphysical processes that determine the particle size distribution. These models enable aerosol optical properties and cloud condensation nuclei (CCN) concentrations to be determined by fundamental aerosol processes, which should lead to a more physically based simulation of aerosol direct and indirect radiative forcings. This study examines the global variation in particle size distribution simulated by twelve global aerosol microphysics models to quantify model diversity and to identify any common biases against observations. Evaluation against size distribution measurements from a new European network of aerosol supersites shows that the mean model agrees quite well with the observations at many sites on the annual mean, but there are some seasonal biases common to many sites. In particular, at many of these European sites, the accumulation mode number concentration is biased low during winter and Aitken mode concentrations tend to be overestimated in winter and underestimated in summer. At high northern latitudes, the models strongly underpredict Aitken and accumulation particle concentrations compared to the measurements, consistent with previous studies that have highlighted the poor performance of global aerosol models in the Arctic. In the marine boundary layer, the models capture the observed meridional variation in the size distribution, which is dominated by the Aitken mode at high latitudes, with an increasing concentration of accumulation particles with decreasing latitude. Considering vertical profiles, the models reproduce the observed peak in total particle concentrations in the upper troposphere due to new particle formation, although modelled peak concentrations tend to be biased high over Europe. Overall, the results suggest that most global aerosol microphysics models simulate the global variation of the particle size distribution with a good degree of skill, but some models are in poor agreement with the observations. Further work is required to better constrain size-resolved primary and secondary particle number sources, and an improved understanding of nucleation and growth (e.g. the role of nitrate and secondary organics) will improve the fidelity of simulated particle size distributions.

  18. An offline unstructured biogeochemical model (UBM) for complex estuarine and coastal environments

    SciTech Connect (OSTI)

    Kim, Tae Yun; Khangaonkar, Tarang

    2012-05-01T23:59:59.000Z

    Due to increased pollutant loads and water use from coastal development and population growth, occurrences of low-dissolved oxygen and "hypoxic zones" have increased. Reports of fish kills and water quality impairment are also becoming more frequent in many coastal waters. Water quality managers and regulatory agencies rely on numerical modeling tools to quantify the relative contributions of anthropogenic and "natural" pollutant loads (nutrients and biochemical oxygen demand) on dissolved oxygen levels and use the results for remedial activities and source control. The ability to conduct seasonlong simulations with sufficient nearshore resolution is therefore a key requirement. Mesh flexibility and the ability to increase site specific resolution without disturbing the larger domain setup and calibration are critical. The objective of this effort was to develop a robust biogeochemical model suitable for simulation of water quality dynamics including dissolved oxygen in complex coastal environments with multiple tidal channels, tidal flats, and density-driven circulation using unstructured-grid formulation. This paper presents an offline unstructured biogeochemical model that uses the Finite Volume Coastal Ocean Model (FVCOM) discretization of the study domain and the corresponding hydrodynamic solution to drive biogeochemical kinetics based on a water quality model CE-QUAL-ICM. In this paper, the linkage between selected hydrodynamic and water quality models is subjected to several scalar transport and biogeochemical module tests (plume transport and dilution, BOD/DO sag, and phytoplankton/nutrients reaction), and results are compared to their analytical solutions as part of model validation. A preliminary application of the biogeochemical model with a year-long simulation of Hood Canal basin in Puget Sound, USA, is presented as an example and a test of the tool in a real estuary setting. The model reproduced the dynamics and seasonal variations in the biogeochemical state variables and was used to test short-term wind-driven dynamics that could influence dissolved oxygen concentrations in Hood Canal.

  19. Climate-derived tensions in Arctic security.

    SciTech Connect (OSTI)

    Backus, George A.; Strickland, James Hassler

    2008-09-01T23:59:59.000Z

    Globally, there is no lack of security threats. Many of them demand priority engagement and there can never be adequate resources to address all threats. In this context, climate is just another aspect of global security and the Arctic just another region. In light of physical and budgetary constraints, new security needs must be integrated and prioritized with existing ones. This discussion approaches the security impacts of climate from that perspective, starting with the broad security picture and establishing how climate may affect it. This method provides a different view from one that starts with climate and projects it, in isolation, as the source of a hypothetical security burden. That said, the Arctic does appear to present high-priority security challenges. Uncertainty in the timing of an ice-free Arctic affects how quickly it will become a security priority. Uncertainty in the emergent extreme and variable weather conditions will determine the difficulty (cost) of maintaining adequate security (order) in the area. The resolution of sovereignty boundaries affects the ability to enforce security measures, and the U.S. will most probably need a military presence to back-up negotiated sovereignty agreements. Without additional global warming, technology already allows the Arctic to become a strategic link in the global supply chain, possibly with northern Russia as its main hub. Additionally, the multinational corporations reaping the economic bounty may affect security tensions more than nation-states themselves. Countries will depend ever more heavily on the global supply chains. China has particular needs to protect its trade flows. In matters of security, nation-state and multinational-corporate interests will become heavily intertwined.

  20. Transport of anthropogenic and biomass burning aerosols from Europe to the Arctic during spring 2008

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

    Marelle, L.; Raut, Jean-Christophe; Thomas, J. L.; Law, K. S.; Quennehen, Boris; Ancellet, G.; Pelon, J.; Schwarzenboeck, A.; Fast, Jerome D.

    2015-01-01T23:59:59.000Z

    During the POLARCAT-France airborne campaign in April 2008, pollution originating from anthropogenic and biomass burning emissions was measured in the European Arctic. We compare these aircraft measurements with simulations using the WRF-Chem model to investigate model representation of aerosols transported from Europe to the Arctic. Modeled PM2.5 is evaluated using European Monitoring and Evaluation Programme (EMEP) measurements in source regions and POLARCAT aircraft measurements in the Scandinavian Arctic. Total PM2.5 agrees well with the measurements, although the model overestimates nitrate and underestimates organic carbon in source regions. Using WRF-Chem in combination with the Lagrangian model FLEXPART-WRF, we find that duringmore »the campaign the research aircraft sampled two different types of European plumes: mixed anthropogenic and fire plumes from eastern Europe and Russia transported below 2 km, and anthropogenic plumes from central Europe uplifted by warm conveyor belt circulations to 5–6 km. Both modeled plume types had undergone significant wet scavenging (> 50% PM10) during transport. Modeled aerosol vertical distributions and optical properties below the aircraft are evaluated in the Arctic using airborne lidar measurements. Model results show that the pollution event transported aerosols into the Arctic (> 66.6° N) for a 4-day period. During this 4-day period, biomass burning emissions have the strongest influence on concentrations between 2.5 and 3 km altitudes, while European anthropogenic emissions influence aerosols at both lower (~ 1.5 km) and higher altitudes (~ 4.5 km). As a proportion of PM2.5, modeled black carbon and SO4= concentrations are more enhanced near the surface in anthropogenic plumes. The European plumes sampled during the POLARCAT-France campaign were transported over the region of springtime snow cover in northern Scandinavia, where they had a significant local atmospheric warming effect. We find that, during this transport event, the average modeled top-of-atmosphere (TOA) shortwave direct and semi-direct radiative effect (DSRE) north of 60° N over snow and ice-covered surfaces reaches +0.58 W m?2, peaking at +3.3 W m?2 at noon over Scandinavia and Finland.« less

  1. The Complex Spherical 2+4 Spin Glass Model: application to optics

    E-Print Network [OSTI]

    Antenucci, Fabrizio; Leuzzi, Luca

    2015-01-01T23:59:59.000Z

    A disordered mean field model for multimode laser in open and irregular cavities is proposed and discussed within the replica analysis. The model includes the dynamics of the mode intensity and accounts also for the possible presence of a linear coupling between the modes, due, e.g., to the leakages from an open cavity. The complete phase diagram, in terms of disorder strength, source pumping and non-linearity, consists of four different optical regimes: incoherent fluorescence, standard mode locking, random lasing and the novel spontaneous phase locking. A replica symmetry breaking phase transition is predicted at the random lasing threshold. For a high enough strength of non-linearity, a whole region with nonvanishing complexity anticipates the transition, and the light modes in the disordered medium display typical discontinuous glassy behavior, i.e., the photonic glass has a multitude of metastable states that corresponds to different mode-locking processes in random lasers. The lasing regime is still pre...

  2. The Arctic Ocean--a Canadian perspective from IPY H. Melling & R. Francois & P. G. Myers & W. Perrie &

    E-Print Network [OSTI]

    Long, Bernard

    ice, enhanced shelf-break upwelling and a maximum in freshwater retention in the Beaufort Gyre the Arctic Oscillation as a dominant cause of long- period climate variations during the Holocene. One a reliable affordable logistic framework, while a wave forecast model developed by another for the Beaufort

  3. Soil carbon sensitivity to temperature and carbon use efficiency compared across microbial-ecosystem models of varying complexity

    SciTech Connect (OSTI)

    Li, Jianwei [University of Oklahoma] [University of Oklahoma; Wang, Gangsheng [ORNL] [ORNL; Allison, Steven D. [University of California, Irvine] [University of California, Irvine; Mayes, Melanie [ORNL] [ORNL; Luo, Yiqi [University of Oklahoma] [University of Oklahoma

    2014-01-01T23:59:59.000Z

    Global ecosystem models may require microbial components to accurately predict feedbacks between climate warming and soil decomposition, but it is unclear what parameters and levels of complexity are ideal for scaling up to the globe. Here we conducted a model comparison using a conventional model with first-order decay and three microbial models of increasing complexity that simulate short- to long-term soil carbon dynamics. We focused on soil carbon responses to microbial carbon use efficiency (CUE) and temperature. Three scenarios were implemented in all models: constant CUE (held at 0.31), varied CUE ( 0.016 C 1), and 50 % acclimated CUE ( 0.008 C 1). Whereas the conventional model always showed soil carbon losses with increasing temperature, the microbial models each predicted a temperature threshold above which warming led to soil carbon gain. The location of this threshold depended on CUE scenario, with higher temperature thresholds under the acclimated and constant scenarios. This result suggests that the temperature sensitivity of CUE and the structure of the soil carbon model together regulate the long-term soil carbon response to warming. Equilibrium soil carbon stocks predicted by the microbial models were much less sensitive to changing inputs compared to the conventional model. Although many soil carbon dynamics were similar across microbial models, the most complex model showed less pronounced oscillations. Thus, adding model complexity (i.e. including enzyme pools) could improve the mechanistic representation of soil carbon dynamics during the transient phase in certain ecosystems. This study suggests that model structure and CUE parameterization should be carefully evaluated when scaling up microbial models to ecosystems and the globe.

  4. 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

  5. Systems Modeling and Analysis Industrial Engineers are interested in optimizing the design and operation of complex systems

    E-Print Network [OSTI]

    Dyer, Bill

    Systems Modeling and Analysis Industrial Engineers are interested in optimizing the design and operation of complex systems composed of people and machines using information, materials and energy to produce goods and services. Analyzing such systems with information-driven models is an essential step

  6. Efficiency of attack strategies on complex model and real-world networks

    E-Print Network [OSTI]

    Bellingeri, Michele; Vincenzi, Simone

    2013-01-01T23:59:59.000Z

    We investigated the efficiency of attack strategies to network nodes when targeting several complex model and real-world networks. We tested 5 attack strategies, 3 of which were introduced in this work for the first time, to attack 3 model (Erdos and Renyi, Barabasi and Albert preferential attachment network, and scale-free network configuration models) and 3 real networks (Gnutella peer-to-peer network, email network of the University of Rovira i Virgili, and immunoglobulin interaction network). Nodes were removed sequentially according to the importance criterion defined by the attack strategy. We used the size of the largest connected component (LCC) as a measure of network damage. We found that the efficiency of attack strategies (fraction of nodes to be deleted for a given reduction of LCC size) depends on the topology of the network, although attacks based on the number of connections of a node and betweenness centrality were often the most efficient strategies. Sequential deletion of nodes in decreasin...

  7. Mercury Issues and Complexities in Oak Ridge, Tennessee; Redefining the Conceptual Model - 12277

    SciTech Connect (OSTI)

    Peterson, Mark; Southworth, George; Watson, David [Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831 (United States); Looney, Brian; Eddy-Dilek, Carol [Savannah River National Laboratory, Aiken, South Carolina 29808 (United States); Ketelle, Richard [Restoration Services Inc., Oak Ridge, Tennessee 37831 (United States)

    2012-07-01T23:59:59.000Z

    Releases of mercury from an industrial facility in Oak Ridge, Tennessee in the 1950's and early 1960's resulted in contamination of soil and groundwater within the facility, as well as downstream surface waters. Remediation efforts, which began in the 1980's, have decreased waterborne mercury concentrations near the facility, but elevated levels of mercury remain in the soil, sediment, water, and biota. Widespread distribution of mercury sources and complex mercury transport pathways are some of many challenges at the site. For effective environmental management and closure decision making relative to mercury contamination at the facilities, an up-to-date conceptual model of mercury source areas, processes, likely flow paths, and flux was deemed necessary. Recent facility and reconfiguration efforts, site characterizations, remedial actions, and research are facilitating the collection of new mercury data in Oak Ridge. To develop the current model, a multi-organizational team reviewed existing conceptual models from a variety of sources, consolidated historical data and source information, gathered input from local experts with extensive site knowledge, and used recently collected mercury data from a variety of sampling programs. The developed site conceptual model indicates that the nature and extent of mercury concentration and contaminant flux has significantly changed in the ten years since flux-based conceptual models were used for previous remedial action decisions. A new water treatment system has effectively reduced mercury inputs to the creek and is removing substantially greater quantities of mercury from groundwater than was expected. However, fish concentrations in downstream waters have not responded to decreased water concentrations in the stream. Flux from one large out-fall at the creek's headwaters appears to be a greater percentage of the overall flux leaving the site than previous years, albeit year to year variation in flux is large, and the many small sources of mercury identified in the model may also be important if the goal is to reach very low mercury levels in stream water and fish. The conceptual model is a key reference in helping to prioritize future remedial actions, defining future monitoring, conducting numerical modeling efforts, and evaluating research needs. (authors)

  8. Model complexes for active sites of diiron metalloproteins, dioxygen reactivity and water effects

    E-Print Network [OSTI]

    Yoon, Sungho, 1971-

    2004-01-01T23:59:59.000Z

    (cont.) tetrairon(II) cubane complex was identified and structurally characterized. Chapter 4: Synthesis and Characterization of [Fe?...CR)]³? and [Fe?...CR)]³? Complexes with Carboxylate-Rich Metal Coordination Environment ...

  9. Materiel availability modeling and analysis for a complex army weapon system.

    SciTech Connect (OSTI)

    Gunther, David W. (US Army); Anderson, Dennis James; Martin, Jeffrey A. (US Army); Hoffman, Matthew J.

    2010-10-01T23:59:59.000Z

    Materiel availability (A{sub m}) is a new US Department of Defense Key Performance Parameter (KPP) implemented through a mandatory Sustainment Metric consisting of an Availability KPP and two supporting Key System Attributes (KSAs), materiel reliability and ownership cost. Sandia National Laboratories (Sandia), in conjunction with several US Army organizations, developed the analytical foundation, assumptions, and brigade-level modeling approach to support lifecycle, fleet-wide A{sub m} modeling and analysis of a complex Army weapon system. Like operational availability (A{sub o}), A{sub m} is dependent on reliability, but A{sub m} is also affected by other factors that do not impact A{sub o}. The largest influences on A{sub m} are technology insertion and reset downtimes. A{sub m} is a different metric from A{sub o}. Whereas A{sub o} is an operational measure, A{sub m} is more of a programmatic measure that spans a much larger timeframe, additional sources of downtime, and additional sources of unscheduled maintenance.

  10. International Snow Science Workshop Grenoble Chamonix Mont-Blanc -2013 Why don't avalanche-dynamics models of higher complexity necessarily

    E-Print Network [OSTI]

    Lenstra, Arjen K.

    -dynamics models of higher complexity necessarily lead to better predictions? Christophe Ancey École Polytechnique worldwide. Paradoxically, the substantial increase in model complexity can lead us to lose sight of the empirical nature of the assumptions used to build the models. Human expertise should still be of paramount

  11. Simplicity versus complexity in modelling groundwater recharge in Chalk catchments Hydrology and Earth System Sciences, 6(5), 927937 (2002) EGS

    E-Print Network [OSTI]

    Paris-Sud XI, Université de

    rainfall. Keywords: Chalk, modelling, groundwater recharge Introduction The Chalk is the main aquiferSimplicity versus complexity in modelling groundwater recharge in Chalk catchments 927 Hydrology and Earth System Sciences, 6(5), 927­937 (2002) © EGS Simplicity versus complexity in modelling groundwater

  12. The Impact of Global Warming on the Carbon Cycle of Arctic Permafrost: An Experimental and Field Based Study

    SciTech Connect (OSTI)

    Onstott, Tullis C [Princeton University; Pffifner, Susan M; Chourey, Karuna [Oak Ridge National Laboratory

    2014-11-07T23:59:59.000Z

    Our results to date indicate that CO2 and CH4 fluxes from organic poor, Arctic cryosols on Axel Heiberg Island are net CH4 sinks and CO2 emitters in contrast to organic-rich peat deposits at sub-Arctic latitudes. This is based upon field observations and a 1.5 year long thawing experiment performed upon one meter long intact cores. The results of the core thawing experiments are in good agreement with field measurements. Metagenomic, metatranscriptomic and metaproteomic analyses indicate that high affinity aerobic methanotrophs belong to the uncultivated USCalpha are present in <1% abundance in these cryosols are are active in the field during the summer and in the core thawing experiments. The methanotrophs are 100 times more abundant than the methanogens. As a result mineral cryosols, which comprise 87% of Arctic tundra, are net methane sinks. Their presence and activity may account for the discrepancies observed between the atmospheric methane concentrations observed in the Arctic predicted by climate models and the observed seasonal fluctuations and decadal trends. This has not been done yet.

  13. 11.1 DEVELOPMENT OF AN IMMERSED BOUNDARY METHOD TO RESOLVE COMPLEX TERRAIN IN THE WEATHER RESEARCH AND FORECASTING MODEL

    E-Print Network [OSTI]

    Chow, Fotini Katopodes

    11.1 DEVELOPMENT OF AN IMMERSED BOUNDARY METHOD TO RESOLVE COMPLEX TERRAIN IN THE WEATHER RESEARCH AND FORECASTING MODEL Katherine A. Lundquist1 , Fotini K. Chow 2 , Julie K. Lundquist 3 , and Jeffery D. Mirocha 3 in urban areas are profoundly influenced by the presence of build- ings which divert mean flow, affect

  14. Winner-Take-All Correlation-Based Complex Networks for Modeling Stock Market and Degree-Based Indexes

    E-Print Network [OSTI]

    Tse, Chi K. "Michael"

    Winner-Take-All Correlation-Based Complex Networks for Modeling Stock Market and Degree are constructed to study corre- lations between the closing prices for all US stocks that were traded from July 1, 2005 to August 30, 2007. The nodes are the stocks, and the connections are determined by cross

  15. Existence of patchiness in constricted lungs : from experiments to complex system modeling

    E-Print Network [OSTI]

    Wongviriyawong, Chanikarn Mint

    2012-01-01T23:59:59.000Z

    Understanding asthma pathophysiology can directly help researchers and physicians pinpoint mechanisms that govern airway hyperresponsiveness and effectively treat complex respiratory diseases such as asthma. The advancement ...

  16. National Strategy for the Arctic Region Stakeholder Outreach...

    Energy Savers [EERE]

    energy deployment in the Arctic Region. The purpose of this round is to give feedback on the elements of the draft plan. DOE encourages stakeholders to provide comments on...

  17. Arctic Ecologies: The Politics and Poetics of Northern Literary Environments

    E-Print Network [OSTI]

    Athens, Allison Katherine

    2013-01-01T23:59:59.000Z

    which lives mainly on pack ice and is a powerful swimmerfor this change: “Arctic pack ice has formed progressivelychanges have resulted in pack ice that is a less stable

  18. National Strategy for the Arctic Tribal Consultation Session...

    Energy Savers [EERE]

    Tribal Consultation Session: Fairbanks National Strategy for the Arctic Tribal Consultation Session: Fairbanks February 19, 2015 9:30AM to 10:30AM AKST Fairbanks, Alaska BLM...

  19. Potential Oil Production from the Coastal Plain of the Arctic...

    U.S. Energy Information Administration (EIA) Indexed Site

    Potential Oil Production from the Coastal Plain of the Arctic National Wildlife Refuge: Updated Assessment 3. Summary The 1.5 million-acre coastal plain of the 19 million-acre...

  20. National Strategy for the Arctic Region Tribal Consultation Session...

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

    Arctic Region Tribal Consultation Session: Dutch HarborUnalaska February 27, 2015 10:00AM to 12:00PM EST Unalaska, Alaska Unalaska Public Library 64 Eleanor Dr. Unalaska, AK 99685...

  1. arctic haze: Topics by E-print Network

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

    Srinivas 7 NASA ARCTAS PROJECT The Arctic. It often serves as the measuring stick for global climate change. It is where warming has been strongest in the past century,...

  2. Integration of 3-D seismic data with reservoir modeling of a stratigraphically complex reservoir, central Saudi Arabia

    SciTech Connect (OSTI)

    Simms, S.C. (Saudi Aramco, Dhahran (Saudi Arabia))

    1993-09-01T23:59:59.000Z

    A 425-km[sup 2], three-dimensional (3-D) seismic survey was shot in 1992 over one of the recently discovered oil fields in central Saudi Arabia. The primary objective of this survey was to provide stratigraphic control within a complex fluvial reservoir. The Permian age reservoir is a multistory, multilateral sequence of sandstones interbedded with nonproductive mudstones and siltstones. The seismic data were integrated with well control from over 50 wells to produce a 3-D geologic model of the reservoir. Numerous examples of the seismic and well data are presented in this case history. Stratigraphic cross sections through the wells illustrate that the complex nature of the reservoir and seismic sections through these wells show good correlation between seismic character and stratigraphy. Meandering channels and massive siltstone/mudstone bodies are clearly visible on seismic horizon slices and time slices. Faulting is evident on both seismic section at times slices. Acoustic impedance sections produced from both forward and inverse modeling of the seismic data are compared with geologic models of porosity and lithology based on well control alone. Good correlation between acoustic impedance and porosity/lithology allow the use of the seismic data to guide the model between well locations. A geostatistical approach was used to interpolate between well control using the inverted seismic as [open quotes]soft data.[close quotes] 3-D visualization of the geological model illustrates increasing complexity from well control only to an integrated model.

  3. The Genetic Prehistory of the New World Arctic

    E-Print Network [OSTI]

    Raghavan, Maanasa; DeGiorgio, Michael; Albrechtsen, Anders; Moltke, Ida; Skoglund, Pontus; Korneliussen, Thorfinn S.; Grønnow, Bjarne; Appelt, Martin; Gulløv, Hans Christian; Friesen, T. Max; Fitzhugh, William; Malmström, Helena; Rasmussen, Simon; Olsen, Jesper; Melchior, Linea; Fuller, Benjamin T.; Fahrni, Simon M.; Stafford, Thomas Jr; Grimes, Vaughan; Renouf, M. A. Priscilla; Cybulski, Jerome; Lynnerup, Niels; Lahr, Marta Mirazon; Britton, Kate; Knecht, Rick; Arneborg, Jette; Metspalu, Mait; Cornejo, Omar E.; Malaspinas, Anna-Sapfo; Wang, Yong; Rasmussen, Morten; Raghavan, Vibha; Hansen, Thomas V. O.; Khusnutdinova, Elza; Pierre, Tracey; Dneprovsky, Kirill; Andreasen, Claus; Lange, Hans; Hayes, M. Geoffrey; Coltrain, Joan; Spitsyn, Victor A.; Götherström, Anders; Orlando, Ludovic; Kivisild, Toomas; Villems, Richard; Crawford, Michael H.; Nielsen, Finn C.; Dissing, Jørgen; Heinemeier, Jan; Meldgaard, Morten; Bustamante, Carlos; O’Rourke, Dennis H.; Jakobsson, Matthias; Gilbert, M. Thomas P.; Nielsen, Rasmus; Willerslev, Eske

    2014-08-29T23:59:59.000Z

    archaeological phases within a culture are separated by a white line. Dark reddish-brown towards the top of the figure indicates historical times. Cultural contexts from which samples included in this study arise are highlighted in yellow. B) A two... -Eskimo beginnings in North America: a new discovery at Kuzitrin Lake, Alaska. Etudes Inuit 22, 61-81 (1998). 2. H. B. Collins, in Prehistoric cultural relations between the arctic and temperate zones of North America, J. M. Campbell, Ed. (Arctic Institute...

  4. Space Complexity Algorithms & Complexity

    E-Print Network [OSTI]

    Way, Andy

    Space Complexity Algorithms & Complexity Space Complexity Nicolas Stroppa Patrik Lambert - plambert@computing.dcu.ie CA313@Dublin City University. 2008-2009. December 4, 2008 #12;Space Complexity Hierarchy of problems #12;Space Complexity NP-intermediate Languages If P = NP, then are there languages which neither in P

  5. The dynamic response of high Arctic glaciers to global warming and their contribution to sea-level rise

    SciTech Connect (OSTI)

    Lam, J.K.W. [Univ. of Cambridge (United Kingdom). Scott Polar Research Inst.; Dowdeswell, J.A. [Univ. of Wales (United Kingdom)

    1995-06-01T23:59:59.000Z

    Simulations with General Circulation Models have indicated that global warming will be enhanced at high latitudes. Regions in the high Arctic are highly sensitive to increased concentrations of greenhouse gases, with an amplified theoretical rise of 8--14 C predicted to take place in winter and a negligible rise of 2 C in summer. Wetter conditions in these regions are quite plausible with global warming due to warmer sea surface temperatures, melting of sea ice and a greater moisture holding capacity of the atmosphere. Recent observations show a marked increase in precipitation in the high Arctic regions during the past decades, particularly in the winters. The notion of whether the increased melting of snow due to global warming would be offset by increased snowfall is investigated in this study. To make reliable predictions of the response of high Arctic glaciers to global warming and hence their contribution to sea-level rise, a numerical model has been developed to investigate the interactions of the glaciers with climate change induced by global warming. The model is a one-dimensional numerical ice-flow model coupled with a surface balance model. Accumulation and ablation at the glacier surface are determined by the surface balance model using an energy balance approach.

  6. Modeling Single Well Injection-Withdrawal (SWIW) Tests for Characterization of Complex Fracture-Matrix Systems

    SciTech Connect (OSTI)

    Cotte, F.P.; Doughty, C.; Birkholzer, J.

    2010-11-01T23:59:59.000Z

    The ability to reliably predict flow and transport in fractured porous rock is an essential condition for performance evaluation of geologic (underground) nuclear waste repositories. In this report, a suite of programs (TRIPOLY code) for calculating and analyzing flow and transport in two-dimensional fracture-matrix systems is used to model single-well injection-withdrawal (SWIW) tracer tests. The SWIW test, a tracer test using one well, is proposed as a useful means of collecting data for site characterization, as well as estimating parameters relevant to tracer diffusion and sorption. After some specific code adaptations, we numerically generated a complex fracture-matrix system for computation of steady-state flow and tracer advection and dispersion in the fracture network, along with solute exchange processes between the fractures and the porous matrix. We then conducted simulations for a hypothetical but workable SWIW test design and completed parameter sensitivity studies on three physical parameters of the rock matrix - namely porosity, diffusion coefficient, and retardation coefficient - in order to investigate their impact on the fracture-matrix solute exchange process. Hydraulic fracturing, or hydrofracking, is also modeled in this study, in two different ways: (1) by increasing the hydraulic aperture for flow in existing fractures and (2) by adding a new set of fractures to the field. The results of all these different tests are analyzed by studying the population of matrix blocks, the tracer spatial distribution, and the breakthrough curves (BTCs) obtained, while performing mass-balance checks and being careful to avoid some numerical mistakes that could occur. This study clearly demonstrates the importance of matrix effects in the solute transport process, with the sensitivity studies illustrating the increased importance of the matrix in providing a retardation mechanism for radionuclides as matrix porosity, diffusion coefficient, or retardation coefficient increase. Interestingly, model results before and after hydrofracking are insensitive to adding more fractures, while slightly more sensitive to aperture increase, making SWIW tests a possible means of discriminating between these two potential hydrofracking effects. Finally, we investigate the possibility of inferring relevant information regarding the fracture-matrix system physical parameters from the BTCs obtained during SWIW testing.

  7. 12.086 / 12.586 Modeling Environmental Complexity, Fall 2008

    E-Print Network [OSTI]

    Rothman, Daniel

    This course provides an introduction to the study of environmental phenomena that exhibit both organized structure and wide variability—i.e., complexity. Through focused study of a variety of physical, biological, ...

  8. Application of the Software as a Service Model to the Control of Complex Building Systems

    E-Print Network [OSTI]

    Stadler, Michael

    2011-01-01T23:59:59.000Z

    cell and PV, electricity in and out of the battery as welloriginal battery specifications are used. Given that the PVPV system and fuel cell, describes the complex optimization applied to the battery

  9. Understanding, modeling and improving the development of complex products : method and study

    E-Print Network [OSTI]

    Rogers, Bradley W. (Bradley Warren)

    2009-01-01T23:59:59.000Z

    Development of new aerostructure designs frequently occurs through a complex process that is difficult to understand and control. Tight requirements for weight, cost, strength, and aerodynamic behavior create many ...

  10. Characterization of a synthetic peroxodiiron(III) protein model complex by nuclear resonance vibrational spectroscopy

    E-Print Network [OSTI]

    Do, Loi Hung

    The vibrational spectrum of an ?[superscript 1],?[superscript 1]-1,2-peroxodiiron(III) complex was measured by nuclear resonance vibrational spectroscopy and fit using an empirical force field analysis. Isotopic 18O2 ...

  11. Engineering Systems Matrix: An organizing framework for modeling large-scale complex systems

    E-Print Network [OSTI]

    Bartolomei, Jason E.

    The scope and complexity of engineered systems are ever-increasing as burgeoning global markets, unprecedented technological capabilities, rising consumer expectations, and ever-changing social requirements present difficult ...

  12. Indirect and Semi-Direct Aerosol Campaign: The Impact of Arctic...

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

    Indirect and Semi-Direct Aerosol Campaign: The Impact of Arctic Aerosols on Clouds . Indirect and Semi-Direct Aerosol Campaign: The Impact of Arctic Aerosols on Clouds . Abstract:...

  13. Small Thaw Ponds: An Unaccounted Source of Methane in the Canadian High Arctic

    E-Print Network [OSTI]

    2013-01-01T23:59:59.000Z

    other Archaea in high Arctic peat. ISME J 2: 37–48. 38. Højmethanogenic pathways in a peat from subarctic permafrost.Canadian Arctic tundra leads to peat erosion and slumping in

  14. Next-Generation Ecosystem Experiments NGEE Arctic Quarterly Report

    E-Print Network [OSTI]

    Clips 10 Appendix 11 #12;2 Can Microbial Community Composition be Incorporated into Earth System Models? Accurate projections of greenhouse gas fluxes by Earth System Models require that they contain process and to mechanistically represent the complex plant-microbe-soil system in Earth System Models. Xu et al. (2011) Feedback

  15. A global conformance quality model. A new strategic tool for minimizing defects caused by variation, error, and complexity

    SciTech Connect (OSTI)

    Hinckley, C.M.

    1994-01-01T23:59:59.000Z

    The performance of Japanese products in the marketplace points to the dominant role of quality in product competition. Our focus is motivated by the tremendous pressure to improve conformance quality by reducing defects to previously unimaginable limits in the range of 1 to 10 parts per million. Toward this end, we have developed a new model of conformance quality that addresses each of the three principle defect sources: (1) Variation, (2) Human Error, and (3) Complexity. Although the role of variation in conformance quality is well documented, errors occur so infrequently that their significance is not well known. We have shown that statistical methods are not useful in characterizing and controlling errors, the most common source of defects. Excessive complexity is also a root source of defects, since it increases errors and variation defects. A missing link in the defining a global model has been the lack of a sound correlation between complexity and defects. We have used Design for Assembly (DFA) methods to quantify assembly complexity and have shown that assembly times can be described in terms of the Pareto distribution in a clear exception to the Central Limit Theorem. Within individual companies we have found defects to be highly correlated with DFA measures of complexity in broad studies covering tens of millions of assembly operations. Applying the global concepts, we predicted that Motorola`s Six Sigma method would only reduce defects by roughly a factor of two rather than orders of magnitude, a prediction confirmed by Motorola`s data. We have also shown that the potential defects rates of product concepts can be compared in the earliest stages of development. The global Conformance Quality Model has demonstrated that the best strategy for improvement depends upon the quality control strengths and weaknesses.

  16. Review of technology for Arctic offshore oil and gas recovery. Appendices

    SciTech Connect (OSTI)

    Sackinger, W. M.

    1980-06-06T23:59:59.000Z

    This volume contains appendices of the following: US Geological Survey Arctic operating orders, 1979; Det Noske Vertas', rules for the design, construction and inspection of offshore technology, 1977; Alaska Oil and Gas Association, industry research projects, March 1980; Arctic Petroleum Operator's Association, industry research projects, January 1980; selected additional Arctic offshore bibliography on sea ice, icebreakers, Arctic seafloor conditions, ice-structures, frost heave and structure icing.

  17. Impacts of Climate Change on Human Access and Resource Development in the Arctic

    E-Print Network [OSTI]

    Stephenson, Scott Ryan

    2014-01-01T23:59:59.000Z

    September 22). Reuters. 56. Budzik, P. (2009). Arctic oilin Alaska, and one in Norway (Budzik, 2009). These fields

  18. Spectroscopic measurement of bromine oxide and ozone in the high Arctic during Polar Sunrise Experiment 1992

    SciTech Connect (OSTI)

    Hausmann, M.; Platt, U. [Universitaet Heidelberg (Germany)] [Universitaet Heidelberg (Germany)

    1994-12-20T23:59:59.000Z

    The authors report the measurement of BrO radical densities and ozone in the Arctic troposphere by means of differential optical absorption using very long paths. They observed levels of BrO which varied from below the detection limit to 17 ppt. Such concentrations alone cannot account for the catalytic destruction of ozone observed during periods of episodic ozone variation. The authors offer a model which involves BrO catalyzed reactions, advection, and atmospheric mixing which they argue could account for the observed ozone depletions.

  19. Modeling, Simulation and Analysis of Complex Networked Systems: A Program Plan for DOE Office of Advanced Scientific Computing Research

    SciTech Connect (OSTI)

    Brown, D L

    2009-05-01T23:59:59.000Z

    Many complex systems of importance to the U.S. Department of Energy consist of networks of discrete components. Examples are cyber networks, such as the internet and local area networks over which nearly all DOE scientific, technical and administrative data must travel, the electric power grid, social networks whose behavior can drive energy demand, and biological networks such as genetic regulatory networks and metabolic networks. In spite of the importance of these complex networked systems to all aspects of DOE's operations, the scientific basis for understanding these systems lags seriously behind the strong foundations that exist for the 'physically-based' systems usually associated with DOE research programs that focus on such areas as climate modeling, fusion energy, high-energy and nuclear physics, nano-science, combustion, and astrophysics. DOE has a clear opportunity to develop a similarly strong scientific basis for understanding the structure and dynamics of networked systems by supporting a strong basic research program in this area. Such knowledge will provide a broad basis for, e.g., understanding and quantifying the efficacy of new security approaches for computer networks, improving the design of computer or communication networks to be more robust against failures or attacks, detecting potential catastrophic failure on the power grid and preventing or mitigating its effects, understanding how populations will respond to the availability of new energy sources or changes in energy policy, and detecting subtle vulnerabilities in large software systems to intentional attack. This white paper outlines plans for an aggressive new research program designed to accelerate the advancement of the scientific basis for complex networked systems of importance to the DOE. It will focus principally on four research areas: (1) understanding network structure, (2) understanding network dynamics, (3) predictive modeling and simulation for complex networked systems, and (4) design, situational awareness and control of complex networks. The program elements consist of a group of Complex Networked Systems Research Institutes (CNSRI), tightly coupled to an associated individual-investigator-based Complex Networked Systems Basic Research (CNSBR) program. The CNSRI's will be principally located at the DOE National Laboratories and are responsible for identifying research priorities, developing and maintaining a networked systems modeling and simulation software infrastructure, operating summer schools, workshops and conferences and coordinating with the CNSBR individual investigators. The CNSBR individual investigator projects will focus on specific challenges for networked systems. Relevancy of CNSBR research to DOE needs will be assured through the strong coupling provided between the CNSBR grants and the CNSRI's.

  20. Arctic sea ice declined rapidly to unprec-edented low extents in the summer of 2007,

    E-Print Network [OSTI]

    Clements, Craig

    Arctic sea ice declined rapidly to unprec- edented low extents in the summer of 2007, raising concern that the Arctic may be on the verge of a fundamental transition toward a seasonal ice cover. Arctic sea ice extent typically attains a seasonal maximum in March and minimum in September. Over

  1. Hydraulic controls of summer Arctic pack ice albedo H. Eicken,1

    E-Print Network [OSTI]

    Eicken, Hajo

    Hydraulic controls of summer Arctic pack ice albedo H. Eicken,1 T. C. Grenfell,2 D. K. Perovich,3 J. Perovich, J. A. Richter-Menge, and K. Frey (2004), Hydraulic controls of summer Arctic pack ice albedo, J that feedback processes involving the input of solar energy and subsequent changes in Arctic pack-ice albedo

  2. September Arctic sea ice predicted to disappear near 2 warming above present

    E-Print Network [OSTI]

    Fischlin, Andreas

    September Arctic sea ice predicted to disappear near 2 C global warming above present Irina; published 24 March 2012. [1] The decline of Arctic sea ice is one of the most visible signs of climate change over the past several decades. Arctic sea ice area shows large interannual variability due

  3. Arctic sea ice velocity field: General circulation and turbulent-like fluctuations

    E-Print Network [OSTI]

    Boyer, Edmond

    Arctic sea ice velocity field: General circulation and turbulent-like fluctuations P. Rampal,1,2 J the Arctic sea ice velocity field as the superposition of a mean field and fluctuations. We study how subtracting the mean field, are analyzed in terms of diffusion properties. Although the Arctic sea ice cover

  4. Carbonaceous species and humic like substances (HULIS) in Arctic snowpack during OASIS field campaign in Barrow

    E-Print Network [OSTI]

    Sheldon, Nathan D.

    Carbonaceous species and humic like substances (HULIS) in Arctic snowpack during OASIS field on snow albedo and arctic atmospheric chemistry. During the OASIS field campaign, in March and April 2009), Carbonaceous species and humic like substances (HULIS) in Arctic snowpack during OASIS field campaign in Barrow

  5. This Page Intentionally Left Blank Next-Generation Ecosystem Experiments (NGEE Arctic)

    E-Print Network [OSTI]

    Lincoln #12;This Page Intentionally Left Blank #12;#12;Next-Generation Ecosystem Experiments--Arctic iv#12;This Page Intentionally Left Blank #12;Next-Generation Ecosystem Experiments (NGEE Arctic This Page Intentionally Left Blank #12;Next-Generation Ecosystem Experiments--Arctic Contents v CONTENTS

  6. Surface salinity fields in the Arctic Ocean and statistical approaches to predicting anomalies and patterns

    E-Print Network [OSTI]

    Golden, Kenneth M.

    to changing environmental conditions. Its surface layer is a key component of the Arctic climate system, which. In this context, the Arctic Ocean surface layer is a critical indicator of climate change in the Arctic [Zaharov. Petersburg, Russia. Ivan Sudakov, Department of Mathematics, University of Utah, Salt Lake City, Utah, USA

  7. NAO influence on net sea ice production and exchanges in the Arctic region

    E-Print Network [OSTI]

    Hu, Aixue

    NAO influence on net sea ice production and exchanges in the Arctic region Aixue Hu National Center of the net sea ice production and the sea ice exchanges between the Arctic and its adjacent seas are studied) is the major factor controlling the net sea ice production in the Arctic region since a thinning ice cover

  8. NAO influence on net sea ice production and exchanges in the Arctic region: a numerical study

    E-Print Network [OSTI]

    Hu, Aixue

    NAO influence on net sea ice production and exchanges in the Arctic region: a numerical study Aixue The variability of net sea ice production and sea ice exchange between the Arctic and its adjacent seas export) is the major factor controlling the net sea ice production in the Arctic region since a thinning

  9. Model--Based 3D Scene Analysis from Stereoscopic Image Sequences An approach for the modelling of complex 3D scenes like outdoor street views from a sequence of

    E-Print Network [OSTI]

    the problems stated above for building a true 3D model of a complex scene from a sequence of stereoscopic image for the modelling of complex 3D scenes like outdoor street views from a sequence of stereoscopic image pairs geometry is generated. Not only the scene geometry but also surface texture is stored within the model. 3D

  10. Arctic Sea Ice Retreat in 2007 Follows Thinning Trend R. W. LINDSAY, J. ZHANG, A. SCHWEIGER, M. STEELE, AND H. STERN

    E-Print Network [OSTI]

    Zhang, Jinlun

    Arctic Sea Ice Retreat in 2007 Follows Thinning Trend R. W. LINDSAY, J. ZHANG, A. SCHWEIGER, M ice extent in the summer of 2007 was unprecedented in the historical record. A coupled ice­ocean model is used to determine the state of the ice and ocean over the past 29 yr to investigate the causes

  11. Preliminary Geospatial Analysis of Arctic Ocean Hydrocarbon Resources

    SciTech Connect (OSTI)

    Long, Philip E.; Wurstner, Signe K.; Sullivan, E. C.; Schaef, Herbert T.; Bradley, Donald J.

    2008-10-01T23:59:59.000Z

    Ice coverage of the Arctic Ocean is predicted to become thinner and to cover less area with time. The combination of more ice-free waters for exploration and navigation, along with increasing demand for hydrocarbons and improvements in technologies for the discovery and exploitation of new hydrocarbon resources have focused attention on the hydrocarbon potential of the Arctic Basin and its margins. The purpose of this document is to 1) summarize results of a review of published hydrocarbon resources in the Arctic, including both conventional oil and gas and methane hydrates and 2) develop a set of digital maps of the hydrocarbon potential of the Arctic Ocean. These maps can be combined with predictions of ice-free areas to enable estimates of the likely regions and sequence of hydrocarbon production development in the Arctic. In this report, conventional oil and gas resources are explicitly linked with potential gas hydrate resources. This has not been attempted previously and is particularly powerful as the likelihood of gas production from marine gas hydrates increases. Available or planned infrastructure, such as pipelines, combined with the geospatial distribution of hydrocarbons is a very strong determinant of the temporal-spatial development of Arctic hydrocarbon resources. Significant unknowns decrease the certainty of predictions for development of hydrocarbon resources. These include: 1) Areas in the Russian Arctic that are poorly mapped, 2) Disputed ownership: primarily the Lomonosov Ridge, 3) Lack of detailed information on gas hydrate distribution, and 4) Technical risk associated with the ability to extract methane gas from gas hydrates. Logistics may control areas of exploration more than hydrocarbon potential. Accessibility, established ownership, and leasing of exploration blocks may trump quality of source rock, reservoir, and size of target. With this in mind, the main areas that are likely to be explored first are the Bering Strait and Chukchi Sea, in spite of the fact that these areas do not have highest potential for future hydrocarbon reserves. Opportunities for improving the mapping and assessment of Arctic hydrocarbon resources include: 1) Refining hydrocarbon potential on a basin-by-basin basis, 2) Developing more realistic and detailed distribution of gas hydrate, and 3) Assessing the likely future scenarios for development of infrastructure and their interaction with hydrocarbon potential. It would also be useful to develop a more sophisticated approach to merging conventional and gas hydrate resource potential that considers the technical uncertainty associated with exploitation of gas hydrate resources. Taken together, additional work in these areas could significantly improve our understanding of the exploitation of Arctic hydrocarbons as ice-free areas increase in the future.

  12. A computational methodology for learning low-complexity surrogate models of process from experiments or simulations. (Paper 679a)

    SciTech Connect (OSTI)

    Cozad, A.; Sahinidis, N.; Miller, D.

    2011-01-01T23:59:59.000Z

    Costly and/or insufficiently robust simulations or experiments can often pose difficulties when their use extends well beyond a single evaluation. This is case with the numerous evaluations of uncertainty quantification, when an algebraic model is needed for optimization, as well as numerous other areas. To overcome these difficulties, we generate an accurate set of algebraic surrogate models of disaggregated process blocks of the experiment or simulation. We developed a method that uses derivative-based and derivative-free optimization alongside machine learning and statistical techniques to generate the set of surrogate models using data sampled from experiments or detailed simulations. Our method begins by building a low-complexity surrogate model for each block from an initial sample set. The model is built using a best subset technique that leverages a mixed-integer linear problem formulation to allow for very large initial basis sets. The models are then tested, exploited, and improved through the use of derivative-free solvers to adaptively sample new simulation or experimental points. The sets of surrogate models from each disaggregated process block are then combined with heat and mass balances around each disaggregated block to generate a full algebraic model of the process. The full model can be used for cheap and accurate evaluations of the original simulation or experiment or combined with design specifications and an objective for nonlinear optimization.

  13. An inverse cascade model for self-organized complexity and natural ...

    E-Print Network [OSTI]

    2005-02-19T23:59:59.000Z

    In this paper we build on earlier work (Gabrielov, et al.1999) and show that the .... sensitive to their initial conditions, they are termed “complex.” The use of the word ..... (22). Noting that with. = 1 we have (sum of the infinite geometrical series).

  14. Turbulent Flow Analysis and Coherent Structure Identification in Experimental Models with Complex Geometries

    E-Print Network [OSTI]

    Amini, Noushin

    2012-02-14T23:59:59.000Z

    through the core of an annular pebble bed VHTR. The complex geometry of the core and the highly turbulent nature of the coolant flow passing through the gaps of fuel pebbles make this case quite challenging. In this experiment, a high frequency Hot Wire...

  15. Bath Institute for Complex Systems Young measure flow as a model for damage

    E-Print Network [OSTI]

    Zimmer, Johannes

    if the energy were to obtain its global minimum. A natural strategy is therefore to search for local minimisers and Johannes Zimmer Bath Institute For Complex Systems Preprint 11/05 (2005) http://www.bath.ac.uk than global minimisation. In particular, the case of a non-coercive elastic energy density of Lennard

  16. Motion Pattern Analysis for Modeling and Recognition of Complex Human Activities

    E-Print Network [OSTI]

    Chowdhury, Amit K. Roy

    , research in activity recognition is moving towards more complex scenes involving multiple objects-mail: amitrc@ee.ucr.edu 1 This work has been partially supported by the DARPA VIRAT program and NSF award IIS to several kinds of activity recognition systems. For example, in a surveillance system, the interest could

  17. The First Example of a Nitrile Hydratase Model Complex that Reversibly Binds Nitriles

    E-Print Network [OSTI]

    Kaminsky, Werner

    with both methanol and acetonitrile to afford a six-coordinate solvent-bound complex. Competitive binding for acetonitrile (H ) -6.2((0.2) kcal/mol, S ) -29.4((0.8) eu), benzonitrile (-4.2((0.6) kcal/mol, S ) -18((3) eu-temperature electronic absorption spectroscopy. Ligand exchange kinetics were examined for acetonitrile, iso

  18. The new WAsP flow model: a fast, linearized Mixed Spectral-Integration model applicable to complex terrain

    E-Print Network [OSTI]

    . There is interest in placing wind turbines in hilly and mountainous areas, due to the potentially high speed commercial PC-based tool to estimate wind resources at a potential wind turbine site, given a set of wind challenge for the wind energy industry is the prediction of the wind resource in complex terrain

  19. Discovery of Novel Complex Metal Hydrides for Hydrogen Storage through Molecular Modeling and Combinatorial Methods

    SciTech Connect (OSTI)

    Lesch, David A; Adriaan Sachtler, J.W. J.; Low, John J; Jensen, Craig M; Ozolins, Vidvuds; Siegel, Don

    2011-02-14T23:59:59.000Z

    UOP LLC, a Honeywell Company, Ford Motor Company, and Striatus, Inc., collaborated with Professor Craig Jensen of the University of Hawaii and Professor Vidvuds Ozolins of University of California, Los Angeles on a multi-year cost-shared program to discover novel complex metal hydrides for hydrogen storage. This innovative program combined sophisticated molecular modeling with high throughput combinatorial experiments to maximize the probability of identifying commercially relevant, economical hydrogen storage materials with broad application. A set of tools was developed to pursue the medium throughput (MT) and high throughput (HT) combinatorial exploratory investigation of novel complex metal hydrides for hydrogen storage. The assay programs consisted of monitoring hydrogen evolution as a function of temperature. This project also incorporated theoretical methods to help select candidate materials families for testing. The Virtual High Throughput Screening served as a virtual laboratory, calculating structures and their properties. First Principles calculations were applied to various systems to examine hydrogen storage reaction pathways and the associated thermodynamics. The experimental program began with the validation of the MT assay tool with NaAlH4/0.02 mole Ti, the state of the art hydrogen storage system given by decomposition of sodium alanate to sodium hydride, aluminum metal, and hydrogen. Once certified, a combinatorial 21-point study of the NaAlH4 â?? LiAlH4 â??Mg(AlH4)2 phase diagram was investigated with the MT assay. Stability proved to be a problem as many of the materials decomposed during synthesis, altering the expected assay results. This resulted in repeating the entire experiment with a mild milling approach, which only temporarily increased capacity. NaAlH4 was the best performer in both studies and no new mixed alanates were observed, a result consistent with the VHTS. Powder XRD suggested that the reverse reaction, the regeneration of the alanate from alkali hydride, Al and hydrogen, was hampering reversibility. The reverse reaction was then studied for the same phase diagram, starting with LiH, NaH, and MgH2, and Al. The study was extended to phase diagrams including KH and CaH2 as well. The observed hydrogen storage capacity in the Al hexahydrides was less than 4 wt. %, well short of DOE targets. The HT assay came on line and after certification with studies on NaAlH4, was first applied to the LiNH2 - LiBH4 - MgH2 phase diagram. The 60-point study elucidated trends within the system locating an optimum material of 0.6 LiNH2 â?? 0.3 MgH2 â?? 0.1 LiBH4 that stored about 4 wt. % H2 reversibly and operated below 220 °C. Also present was the phase Li4(NH2)3BH4, which had been discovered in the LiNH2 -LiBH4 system. This new ternary formulation performed much better than the well-known 2 LiNH2 â?? MgH2 system by 50 °C in the HT assay. The Li4(NH2)3BH4 is a low melting ionic liquid under our test conditions and facilitates the phase transformations required in the hydrogen storage reaction, which no longer relies on a higher energy solid state reaction pathway. Further study showed that the 0.6 LiNH2 â?? 0.3 MgH2 â?? 0.1 LiBH4 formulation was very stable with respect to ammonia and diborane desorption, the observed desorption was from hydrogen. This result could not have been anticipated and was made possible by the efficiency of HT combinatorial methods. Investigation of the analogous LiNH2 â?? LiBH4 â?? CaH2 phase diagram revealed new reversible hydrogen storage materials 0.625 LiBH4 + 0.375 CaH2 and 0.375 LiNH2 + 0.25 LiBH4 + 0.375 CaH2 operating at 1 wt. % reversible hydrogen below 175 °C. Powder x-ray diffraction revealed a new structure for the spent materials which had not been previously observed. While the storage capacity was not impressive, an important aspect is that it boron appears to participate in a low temperature reversible reaction. The last major area of study also focused

  20. Application of Aspect-based Modeling and Weaving for Complexity Reduction in Development of Automotive

    E-Print Network [OSTI]

    Schmidt, Douglas C.

    of Automotive Distributed Real-time Embedded System Andrey Nechypurenko, Egon Wuchner Siemens AG, Corporate the stringent resource and costs constraints in de- veloping modern automotive embedded electronic systems collaboration model, and timing models. An emerging trend in automotive sys- tems is to apply Model

  1. Reduction of U(VI) Complexes by Anthraquinone Disulfonate: Experiment and Molecular Modeling

    SciTech Connect (OSTI)

    Ainsworth, C.C.; Wang, Z.; Rosso, K.M.; Wagnon, K.; Fredrickson, J.K.

    2004-03-17T23:59:59.000Z

    Past studies demonstrate that complexation will limit abiotic and biotic U(VI) reduction rates and the overall extent of reduction. However, the underlying basis for this behavior is not understood and presently unpredictable across species and ligand structure. The central tenets of these investigations are: (1) reduction of U(VI) follows the electron-transfer (ET) mechanism developed by Marcus; (2) the ET rate is the rate-limiting step in U(VI) reduction and is the step that is most affected by complexation; and (3) Marcus theory can be used to unify the apparently disparate U(VI) reduction rate data and as a computational tool to construct a predictive relationship.

  2. Network Analysis in the Legal Domain: A complex model for European Union legal sources

    E-Print Network [OSTI]

    Koniaris, Marios; Vassiliou, Yannis

    2015-01-01T23:59:59.000Z

    Legislators, designers of legal information systems, as well as citizens face often problems due to the interdependence of the laws and the growing number of references needed to interpret them. Quantifying this complexity is not an easy task. In this paper, we introduce the "Legislation Network" as a novel approach to address related problems. We have collected an extensive data set of a more than 60-year old legislation corpus, as published in the Official Journal of the European Union, and we further analysed it as a complex network, thus gaining insight into its topological structure. Among other issues, we have performed a temporal analysis of the evolution of the Legislation Network, as well as a robust resilience test to assess its vulnerability under specific cases that may lead to possible breakdowns. Results are quite promising, showing that our approach can lead towards an enhanced explanation in respect to the structure and evolution of legislation properties.

  3. The Arctic Lower Troposphere Observed Structure (ALTOS) Campaign

    SciTech Connect (OSTI)

    Verlinde, J

    2010-10-18T23:59:59.000Z

    The ALTOS campaign focuses on operating a tethered observing system for routine in situ sampling of low-level (< 2 km) Arctic clouds. It has been a long-term hope to fly tethered systems at Barrow, Alaska, but it is clear that the Federal Aviation Administration (FAA) will not permit in-cloud tether systems at Barrow, even if unmanned aerial vehicle (UAV) operations are allowed in the future. We have provided the scientific rationale for long-term, routine in situ measurements of cloud and aerosol properties in the Arctic. The existing restricted air space at Oliktok offers an opportunity to do so.

  4. Comprehensive Thermodynamics of Nickel Hydride Bis(Diphosphine) Complexes: A Predictive Model through Computations

    SciTech Connect (OSTI)

    Chen, Shentan; Rousseau, Roger J.; Raugei, Simone; Dupuis, Michel; DuBois, Daniel L.; Bullock, R. Morris

    2011-11-28T23:59:59.000Z

    Prediction of thermodynamic quantities such as redox potentials and homolytic and heterolytic metal hydrogen bond energies is critical to the a priori design of molecular catalysts. In this paper we expound upon a density functional theory (DFT)-based isodesmic methodology for the accurate computation of the above quantities across a series of Ni(diphosphine)2 complexes compounds that are potential catalysts for production of H2 from protons and electrons, or oxidation of H2 to electrons and protons. Isodesmic schemes give relative free energies between the complex of interest and a reference system. A natural choice is to use as a reference a compound that shares similarities with the chemical species under study and for which the properties of interest have been measured with accuracy. However, this is not always possible as in the case of the Ni complexes considered here where data are experimentally available for only some species. To overcome this difficulty we employed a theoretical reference compound, Ni(PH3)4, which is amenable to highly accurate electron-correlated calculations, which allows one to explore thermodynamics properties even when no experimental input is accessible. The reliability of this reference is validated against the available thermodynamics data in acetonitrile solution. Overall the proposed protocol yields excellent accuracy for redox potentials (~ 0.10 eV of accuracy), for acidities (~1.5 pKa units of accuracy), for hydricities (~2 kcal/mol of accuracy), and for homolytic bond dissociation free energies (~ 1-2 kcal/mol of accuracy). The calculated thermodynamic properties are then analyzed for a broad set of Ni complexes. The power of the approach is demonstrated through the validation of previously reported linear correlations among properties. New correlations are revealed. It emerges that only two quantities, the Ni(II)/Ni(I) and Ni(I)/Ni(0) redox potentials (which are easily accessible experimentally), suffice to predict with high confidence the energetics of all relevant species involved in the catalytic cycles for H2 oxidation and production. The approach is extendable to other transition metal complexes. This material is based upon work supported as part of the Center for Molecular Electrocatalysis, an Energy Frontier Research Center funded by the US Department of Energy, Office of Science, Office of Basic Energy Sciences.

  5. Simulating mixed-phase Arctic stratus clouds: Sensitivity to ice initiationmechanisms

    SciTech Connect (OSTI)

    Sednev, I.; Menon, S.; McFarquhar, G.

    2009-04-10T23:59:59.000Z

    The importance of Arctic mixed-phase clouds on radiation and the Arctic climate is well known. However, the development of mixed-phase cloud parameterization for use in large scale models is limited by lack of both related observations and numerical studies using multidimensional models with advanced microphysics that provide the basis for understanding the relative importance of different microphysical processes that take place in mixed-phase clouds. To improve the representation of mixed-phase cloud processes in the GISS GCM we use the GISS single-column model coupled to a bin resolved microphysics (BRM) scheme that was specially designed to simulate mixed-phase clouds and aerosol-cloud interactions. Using this model with the microphysical measurements obtained from the DOE ARM Mixed-Phase Arctic Cloud Experiment (MPACE) campaign in October 2004 at the North Slope of Alaska, we investigate the effect of ice initiation processes and Bergeron-Findeisen process (BFP) on glaciation time and longevity of single-layer stratiform mixed-phase clouds. We focus on observations taken during October 9th-10th, which indicated the presence of a single-layer mixed-phase clouds. We performed several sets of 12-hour simulations to examine model sensitivity to different ice initiation mechanisms and evaluate model output (hydrometeors concentrations, contents, effective radii, precipitation fluxes, and radar reflectivity) against measurements from the MPACE Intensive Observing Period. Overall, the model qualitatively simulates ice crystal concentration and hydrometeors content, but it fails to predict quantitatively the effective radii of ice particles and their vertical profiles. In particular, the ice effective radii are overestimated by at least 50%. However, using the same definition as used for observations, the effective radii simulated and that observed were more comparable. We find that for the single-layer stratiform mixed-phase clouds simulated, process of ice phase initiation due to freezing of supercooled water in both saturated and subsaturated (w.r.t. water) environments is as important as primary ice crystal origination from water vapor. We also find that the BFP is a process mainly responsible for the rates of glaciation of simulated clouds. These glaciation rates cannot be adequately represented by a water-ice saturation adjustment scheme that only depends on temperature and liquid and solid hydrometeors contents as is widely used in bulk microphysics schemes and are better represented by processes that also account for supersaturation changes as the hydrometeors grow.

  6. Simulating mixed-phase Arctic stratus clouds: sensitivity to ice initiation mechanisms

    SciTech Connect (OSTI)

    Sednev, Igor; Sednev, I.; Menon, S.; McFarquhar, G.

    2008-02-18T23:59:59.000Z

    The importance of Arctic mixed-phase clouds on radiation and the Arctic climate is well known. However, the development of mixed-phase cloud parameterization for use in large scale models is limited by lack of both related observations and numerical studies using multidimensional models with advanced microphysics that provide the basis for understanding the relative importance of different microphysical processes that take place in mixed-phase clouds. To improve the representation of mixed-phase cloud processes in the GISS GCM we use the GISS single-column model coupled to a bin resolved microphysics (BRM) scheme that was specially designed to simulate mixed-phase clouds and aerosol-cloud interactions. Using this model with the microphysical measurements obtained from the DOE ARM Mixed-Phase Arctic Cloud Experiment (MPACE) campaign in October 2004 at the North Slope of Alaska, we investigate the effect of ice initiation processes and Bergeron-Findeisen process (BFP) on glaciation time and longevity of single-layer stratiform mixed-phase clouds. We focus on observations taken during 9th-10th October, which indicated the presence of a single-layer mixed-phase clouds. We performed several sets of 12-h simulations to examine model sensitivity to different ice initiation mechanisms and evaluate model output (hydrometeors concentrations, contents, effective radii, precipitation fluxes, and radar reflectivity) against measurements from the MPACE Intensive Observing Period. Overall, the model qualitatively simulates ice crystal concentration and hydrometeors content, but it fails to predict quantitatively the effective radii of ice particles and their vertical profiles. In particular, the ice effective radii are overestimated by at least 50%. However, using the same definition as used for observations, the effective radii simulated and that observed were more comparable. We find that for the single-layer stratiform mixed-phase clouds simulated, process of ice phase initiation due to freezing of supercooled water in both saturated and undersaturated (w.r.t. water) environments is as important as primary ice crystal origination from water vapor. We also find that the BFP is a process mainly responsible for the rates of glaciation of simulated clouds. These glaciation rates cannot be adequately represented by a water-ice saturation adjustment scheme that only depends on temperature and liquid and solid hydrometeors contents as is widely used in bulk microphysics schemes and are better represented by processes that also account for supersaturation changes as the hydrometeors grow.

  7. Computer aided modeling and simulation of complex physical systems, using components from multiple

    E-Print Network [OSTI]

    Zhao, Yuxiao

    .g., Modelica[1], gPROMS[2], and VHDL-AMS[3]) based on acausal modeling using Differential Algebraic Equations units (e.g., newton, meter, and ampere). Separately Compiled Components In for example Modelica Modelica models collected from industry to MKL. Perform experiments on a prototype implementation of MKL

  8. Modeling Complex Control Systems to Identify Remotely Accessible Devices Vulnerable to Cyber Attack1

    E-Print Network [OSTI]

    Krings, Axel W.

    : Security, Vulnerabilities, Cyber Attack, Critical Infrastructure Protection, Electric Power Management present a model developed for Electric Power Management Systems (EPMS) and Supervisory Control and Data vulnerable to cyber attack. We use graph theory to model electric power control and protection devices

  9. Energy and Uncertainty: Models and Algorithms for Complex Energy Systems Warren B. Powell

    E-Print Network [OSTI]

    Powell, Warren B.

    a community. Ignoring for the moment our inability to agree on the right way to write down these problems (generation, transmission, storage, investment) introduces a number of optimization problems which need a way of modeling them that represents a slight departure from the classical modeling frameworks used

  10. Graph-based simulated annealing: A hybrid approach to stochastic modeling of complex

    E-Print Network [OSTI]

    Kroese, Dirk P.

    microstructure of (uncompressed) graphite electrodes used in Li-ion batteries. In Thiedmann et al. (2011), another stochastic simulation model for (compressed) graphite electrodes used in Li-ion batteries the microstructure of electrodes in Li- ion batteries. The goodness of model fit is validated by comparing

  11. Underwater ambient noise in the Alaskan Arctic from 20062009

    E-Print Network [OSTI]

    Frandsen, Jannette B.

    , a proxy for multiyear ice. Perennial pack ice is diminishing while thin seasonal pack ice is more The Arctic Ocean has experienced diminished ice cover as record lows have been measured for sea ice thickness prevalent. These changes in sea ice affect the acoustic field as well as the sources of sound, both natural

  12. arctic energy technology: Topics by E-print Network

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

    arctic energy technology First Page Previous Page 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 Next Page Last Page Topic Index 1 Energy distribution in an...

  13. arctic van test: Topics by E-print Network

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

    arctic van test First Page Previous Page 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 Next Page Last Page Topic Index 1 Action Refinement in Testing with uioco...

  14. UnderSea Solutions, Inc. Arctic AUV Proposal

    E-Print Network [OSTI]

    Wood, Stephen L.

    the conceptual design and analysis of an AUV, Autonomous Underwater Vehicle, for Arctic under-ice water sampling Electrical Design: ? Power Consumption ? Battery Requirements & Selection ? Thrust Motor Requirements for nose cone Lift points Hull Form The hydrodynamic form of the AUV determines the propulsion energy

  15. Arctic EnginEEring College of Engineering and Mines

    E-Print Network [OSTI]

    Hartman, Chris

    Arctic EnginEEring College of Engineering and Mines Department of Civil and Environmental Engineering Management. See Environmental Engineering and Environmental Quality Science. See Science Engineering 907-474-7241 http://cem.uaf.edu/cee/ MS Degree Minimum Requirements for Degree: 30 credits

  16. A new way to study the changing Arctic ecosystem

    ScienceCinema (OSTI)

    Hubbard, Susan

    2013-05-29T23:59:59.000Z

    Berkeley Lab scientists Susan Hubbard and Margaret Torn discuss the proposed Next Generation Ecosystem Experiment, which is designed to answer one of the most urgent questions facing researchers today: How will a changing climate impact the Arctic, and how will this in turn impact the planet's climate? More info: http://newscenter.lbl.gov/feature-stories/2011/09/14/alaska-climate-change/

  17. Global warming and Arctic climate. Raymond S. Bradley

    E-Print Network [OSTI]

    Mountziaris, T. J.

    Global warming and Arctic climate. Raymond S. Bradley Climate System Research Center University of Massachusetts Amherst #12;How have global temperatures changed & why? 1. Average instrumental records from around the world; express all as anomalies from 1961-90 average #12;#12;Overall trend is upward ("global

  18. arctic food web: Topics by E-print Network

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

    arctic food web First Page Previous Page 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 Next Page Last Page Topic Index 1 Perfluoroalkyl Contaminants in an...

  19. Critical Infrastructure Modeling: An Approach to Characterizing Interdependencies of Complex Networks & Control Systems

    SciTech Connect (OSTI)

    Stuart Walsh; Shane Cherry; Lyle Roybal

    2009-05-01T23:59:59.000Z

    Critical infrastructure control systems face many challenges entering the 21st century, including natural disasters, cyber attacks, and terrorist attacks. Revolutionary change is required to solve many existing issues, including gaining greater situational awareness and resiliency through embedding modeling and advanced control algorithms in smart sensors and control devices instead of in a central controller. To support design, testing, and component analysis, a flexible simulation and modeling capability is needed. Researchers at Idaho National Laboratory are developing and evaluating such a capability through their CIPRsim modeling and simulation framework.

  20. Second cancer incidence risk estimates using BEIR VII models for standard and complex external beam radiotherapy for early breast cancer

    SciTech Connect (OSTI)

    Donovan, E. M.; James, H.; Bonora, M.; Yarnold, J. R.; Evans, P. M. [Joint Department of Physics, Royal Marsden NHS Foundation Trust and Institute of Cancer Research, Sutton SM2 5PT (United Kingdom); Physics Department, Ipswich Hospital NHS Foundation Trust, Ipswich IP4 5PD (United Kingdom); Department of Academic Radiotherapy, Institute of Cancer Research and Royal Marsden NHS Foundation Trust, Sutton SM2 5PT, United Kingdom and School of Radiotherapy, University of Milan, Milan 20122 (Italy); Department of Academic Radiotherapy, Institute of Cancer Research and Royal Marsden NHS Foundation Trust, Sutton SM2 5PT (United Kingdom); Centre for Vision Speech and Signal Processing, University of Surrey, Guildford GU2 7XH (United Kingdom)

    2012-10-15T23:59:59.000Z

    Purpose: To compare organ specific cancer incidence risks for standard and complex external beam radiotherapy (including cone beam CT verification) following breast conservation surgery for early breast cancer.Method: Doses from breast radiotherapy and kilovoltage cone beam CT (CBCT) exposures were obtained from thermoluminescent dosimeter measurements in an anthropomorphic phantom in which the positions of radiosensitive organs were delineated. Five treatment deliveries were investigated: (i) conventional tangential field whole breast radiotherapy (WBRT), (ii) noncoplanar conformal delivery applicable to accelerated partial beast irradiation (APBI), (iii) two-volume simultaneous integrated boost (SIB) treatment, (iv) forward planned three-volume SIB, and (v) inverse-planned three volume SIB. Conformal and intensity modulated radiotherapy methods were used to plan the complex treatments. Techniques spanned the range from simple methods appropriate for patient cohorts with a low cancer recurrence risk to complex plans relevant to cohorts with high recurrence risk. Delineated organs at risk included brain, salivary glands, thyroid, contralateral breast, left and right lung, esophagus, stomach, liver, colon, and bladder. Biological Effects of Ionizing Radiation (BEIR) VII cancer incidence models were applied to the measured mean organ doses to determine lifetime attributable risk (LAR) for ages at exposure from 35 to 80 yr according to radiotherapy techniques, and included dose from the CBCT imaging. Results: All LAR decreased with age at exposure and were lowest for brain, thyroid, liver, and bladder (<0.1%). There was little dependence of LAR on radiotherapy technique for these organs and for colon and stomach. LAR values for the lungs for the three SIB techniques were two to three times those from WBRT and APBI. Uncertainties in the LAR models outweigh any differences in lung LAR between the SIB methods. Constraints in the planning of the SIB methods ensured that contralateral breast doses and LAR were comparable to WBRT, despite their added complexity. The smaller irradiated volume of the ABPI plan contributed to a halving of LAR for contralateral breast compared with the other plan types. Daily image guided radiotherapy (IGRT) for a left breast protocol using kilovoltage CBCT contributed <10% to LAR for the majority of organs, and did not exceed 22% of total organ dose. Conclusions: Phantom measurements and calculations of LAR from the BEIR VII models predict that complex breast radiotherapy techniques do not increase the theoretical risk of second cancer incidence for organs distant from the treated breast, or the contralateral breast where appropriate plan constraints are applied. Complex SIB treatments are predicted to increase the risk of second cancer incidence in the lungs compared to standard whole breast radiotherapy; this is outweighed by the threefold reduction in 5 yr local recurrence risk for patients of high risk of recurrence, and young age, from the use of radiotherapy. APBI may have a favorable impact on risk of second cancer in the contralateral breast and lung for older patients at low risk of recurrence. Intensive use of IGRTincreased the estimated values of LAR but these are dominated by the effect of the dose from the radiotherapy, and any increase in LAR from IGRT is much lower than the models' uncertainties.

  1. Complex Dynamics in Equilibrium Asset Pricing Models with Boundedly Rational, Heterogeneous

    E-Print Network [OSTI]

    their optimal portfolio and the market equilibrium, investors must compute future aggregate demands for assets] for critiques of equilibrium models and the response [4] by Robert Lucas. 3The Lucas [5] paper is one one

  2. Mode Estimation of Model-based Programs: Monitoring Systems with Complex Behavior

    E-Print Network [OSTI]

    Williams, Brian C.

    - active programming constructs with probabilistic, constraint-based modeling, and that offers a sim- ple controllers, have simple behaviors. However, the above trajectory spends most of its time wend- ing its way

  3. Mode Estimation of Model-based Programs: Monitoring Systems with Complex Behavior

    E-Print Network [OSTI]

    Williams, Brian C.

    that combines reactive programming constructs with probabilistic, constraint-based modeling, and that offers wending its way through software functions. DS-1 is an instance of modern embedded systems whose

  4. SINARI page 1/6 Towards a Complex Networks Modeling of

    E-Print Network [OSTI]

    Boyer, Edmond

    , and distribution of oil, gas, and electric power. However, this infrastructure integrates high-speed, reliable, bi Critical Infrastructures: Information and Communication Technologies (ICT) and Power Systems. Modeling inherent vulnerabilities of coupled infrastructures to be identified. The method is demonstrated

  5. 10.1098/rsta.2000.0751 Nonlinear models for complex dynamics

    E-Print Network [OSTI]

    of polycarbonate plastic is reviewed. The authors draw the conclusion that single-degree-of-freedom models new experimental results in non-regenerative cutting of polycarbonate plastic that associates chaos

  6. Current Challenges for Modeling Enzyme Active Sites by Biomimetic Synthetic Diiron Complexes

    E-Print Network [OSTI]

    Friedle, Simone

    This tutorial review describes recent progress in modeling the active sites of carboxylate-rich non-heme diiron enzymes that activate dioxygen to carry out several key reactions in Nature. The chemistry of soluble methane ...

  7. The Simplest Walking Model: Stability, Complexity, and Scaling Mariano Garcia Anindya Chatterjee Andy Ruina Michael Coleman

    E-Print Network [OSTI]

    Ruina, Andy L.

    become chaotic through a sequence of period doublings. Scaling laws for the model predict that walking speed is proportional to stance angle, stance angle is proportional to 1/3 , and that the gravitational

  8. Improving capabilities for dealing with key complexities of water availability modeling

    E-Print Network [OSTI]

    Olmos Alejo, Hector Elias

    2005-02-17T23:59:59.000Z

    SYSTEM MANAGEMENT STRATEGIES AND MODELING PREMISES....................... 55 4.1 Single Reservoir Yield-Reliability Tables for Each BRA Reservoir..... 57 4.2 Yield-Reliability Tables for System Diversion at Cameron, Glen Rose, High Banks, and Gulf... management strategies and modeling premises for the Brazos River Authority System ? Evaluate the impact of the beginning storage adopted for the WRAP simulation on reliabilities and firm yields for reservoirs in the Brazos River Authority System...

  9. Thermally Induced Chemistry of Meteoritic Complex Organic Molecules: A New Heat-Diffusion Model for the Atmospheric Entry of Meteorites

    E-Print Network [OSTI]

    Shingledecker, Christopher N

    2014-01-01T23:59:59.000Z

    Research over the past four decades has shown a rich variety of complex organic molecular content in some meteorites. This current study is an attempt to gain a better insight into the thermal conditions experienced by these molecules inside meteorites during atmospheric entry. In particular, we wish to understand possible chemical processes that can occur during entry and that might have had an effect on complex organic or prebiotic species that were delivered in this way to the early Earth. A simulation was written in Fortran to model heating by the shock generated during entry and the subsequent thermal diffusion inside the body of a meteorite. Experimental data was used for the thermal parameters of several types of meteorites, including iron-nickel and several classes of chondrites. A Sutton-Graves model of stagnation-point heating was used to calculate peak surface temperatures and an explicit difference formula was used to generate thermal diffusion profiles for both chondrites and iron-nickel type met...

  10. Review of technology for Arctic offshore oil and gas recovery

    SciTech Connect (OSTI)

    Sackinger, W. M.

    1980-08-01T23:59:59.000Z

    The technical background briefing report is the first step in the preparation of a plan for engineering research oriented toward Arctic offshore oil and gas recovery. A five-year leasing schedule for the ice-prone waters of the Arctic offshore is presented, which also shows the projected dates of the lease sale for each area. The estimated peak production rates for these areas are given. There is considerable uncertainty for all these production estimates, since no exploratory drilling has yet taken place. A flow chart is presented which relates the special Arctic factors, such as ice and permafrost, to the normal petroleum production sequence. Some highlights from the chart and from the technical review are: (1) in many Arctic offshore locations the movement of sea ice causes major lateral forces on offshore structures, which are much greater than wave forces; (2) spray ice buildup on structures, ships and aircraft will be considerable, and must be prevented or accommodated with special designs; (3) the time available for summer exploratory drilling, and for deployment of permanent production structures, is limited by the return of the pack ice. This time may be extended by ice-breaking vessels in some cases; (4) during production, icebreaking workboats will service the offshore platforms in most areas throughout the year; (5) transportation of petroleum by icebreaking tankers from offshore tanker loading points is a highly probable situation, except in the Alaskan Beaufort; and (6) Arctic pipelines must contend with permafrost, making instrumentation necessary to detect subtle changes of the pipe before rupture occurs.

  11. Application of the Software as a Service Model to the Control of Complex Building Systems

    SciTech Connect (OSTI)

    Stadler, Michael; Donadee, Jonathan; Marnay, Chris; Mendes, Goncalo; Appen, Jan von; Megel, Oliver; Bhattacharya, Prajesh; DeForest, Nicholas; Lai, Judy

    2011-03-17T23:59:59.000Z

    In an effort to create broad access to its optimization software, Lawrence Berkeley National Laboratory (LBNL), in collaboration with the University of California at Davis (UC Davis) and OSISoft, has recently developed a Software as a Service (SaaS) Model for reducing energy costs, cutting peak power demand, and reducing carbon emissions for multipurpose buildings. UC Davis currently collects and stores energy usage data from buildings on its campus. Researchers at LBNL sought to demonstrate that a SaaS application architecture could be built on top of this data system to optimize the scheduling of electricity and heat delivery in the building. The SaaS interface, known as WebOpt, consists of two major parts: a) the investment& planning and b) the operations module, which builds on the investment& planning module. The operational scheduling and load shifting optimization models within the operations module use data from load prediction and electrical grid emissions models to create an optimal operating schedule for the next week, reducing peak electricity consumption while maintaining quality of energy services. LBNL's application also provides facility managers with suggested energy infrastructure investments for achieving their energy cost and emission goals based on historical data collected with OSISoft's system. This paper describes these models as well as the SaaS architecture employed by LBNL researchers to provide asset scheduling services to UC Davis. The peak demand, emissions, and cost implications of the asset operation schedule and investments suggested by this optimization model are analysed.

  12. Application of the Software as a Service Model to the Control of Complex Building Systems

    SciTech Connect (OSTI)

    Stadler, Michael; Donadee, Jon; Marnay, Chris; Lai, Judy; Mendes, Goncalo; Appen, Jan von; M& #233; gel, Oliver; Bhattacharya, Prajesh; DeForest, Nicholas; Lai, Judy

    2011-03-18T23:59:59.000Z

    In an effort to create broad access to its optimization software, Lawrence Berkeley National Laboratory (LBNL), in collaboration with the University of California at Davis (UC Davis) and OSISoft, has recently developed a Software as a Service (SaaS) Model for reducing energy costs, cutting peak power demand, and reducing carbon emissions for multipurpose buildings. UC Davis currently collects and stores energy usage data from buildings on its campus. Researchers at LBNL sought to demonstrate that a SaaS application architecture could be built on top of this data system to optimize the scheduling of electricity and heat delivery in the building. The SaaS interface, known as WebOpt, consists of two major parts: a) the investment& planning and b) the operations module, which builds on the investment& planning module. The operational scheduling and load shifting optimization models within the operations module use data from load prediction and electrical grid emissions models to create an optimal operating schedule for the next week, reducing peak electricity consumption while maintaining quality of energy services. LBNL's application also provides facility managers with suggested energy infrastructure investments for achieving their energy cost and emission goals based on historical data collected with OSISoft's system. This paper describes these models as well as the SaaS architecture employed by LBNL researchers to provide asset scheduling services to UC Davis. The peak demand, emissions, and cost implications of the asset operation schedule and investments suggested by this optimization model are analyzed.

  13. RGPS/Model Ice Deformation July 3, 2003 1 Sea Ice Deformation Rates From Satellite Measurements and in a Model

    E-Print Network [OSTI]

    Lindsay, Ron

    of the Arctic geophysical environment. The deformation rate of pack ice, determined from the spatial gradientsRGPS/Model Ice Deformation July 3, 2003 1 Sea Ice Deformation Rates From Satellite Measurements The deformation of sea ice is an important element of the Arctic climate system because of its influence

  14. Composition-Space Model for the Investigation of Complex Molecular Architectures near Interfaces with

    E-Print Network [OSTI]

    Loesche, Mathias

    #12;Keywords Model membrane, supported bilayer, tethered bilayer, reflectometry, neutron scattering of scattering techniques, such questions are arguably best investigated with x-ray or neutron reflectometry (XR with Scattering Techniques Frank Heinrich,1,2,a) Prabhanshu Shekhar,2) Hirsh Nanda,1) Mathias Lösche1,2,3,b) 1The

  15. Organometallic Complexes that Model the Active Sites of the [FeFe]- and [Fe]-Hydrogenases 

    E-Print Network [OSTI]

    Liu, Tianbiao

    2011-02-22T23:59:59.000Z

    My research primarily focuses on biomimetics of the active sites of the [FeFe]- and [Fe]-hydrogenases (H2ase) and is classified into three parts. Part A: The one-electron oxidation of asymmetrically disubstituted FeIFeI models of the active site...

  16. Researchers at the National Renewable Energy Laboratory (NREL) develop a new complex modeling and analysis tool

    E-Print Network [OSTI]

    and analysis tool capable of analyzing floating platform concepts for offshore wind turbines. The new modeling tool combines the computational methodologies used to analyze land-based wind turbines dynamic simulation tool will enable the development of cost-effective offshore technologies capable

  17. Organometallic Complexes that Model the Active Sites of the [FeFe]- and [Fe]-Hydrogenases

    E-Print Network [OSTI]

    Liu, Tianbiao

    2011-02-22T23:59:59.000Z

    My research primarily focuses on biomimetics of the active sites of the [FeFe]- and [Fe]-hydrogenases (H2ase) and is classified into three parts. Part A: The one-electron oxidation of asymmetrically disubstituted FeIFeI models of the active site...

  18. A Framework for Dynamic Safety and Risk Management Modeling in Complex Engineering Systems

    E-Print Network [OSTI]

    Leveson, Nancy

    analysis (FTA), and probabilistic risk analysis (PRA) rely on a chain-of-event paradigm of accident analysis or risk assessment techniques, such as failure modes and effect analysis (FMEA), fault tree and organizational boundaries. STAMP (System-Theoretic Accident Model and Processes) is a comprehensive accident

  19. Redox control of electric melters with complex feed compositions. Part I: analytical methods and models

    SciTech Connect (OSTI)

    Bickford, D F; Diemer, Jr, R B

    1985-01-01T23:59:59.000Z

    The redox state of glass from electric melters with complex feed compositions is determined by balance between gases above the melt, and transition metals and organic compounds in the feed. Part I discusses experimental and computational methods of relating flowrates and other melter operating conditions to the redox state of glass, and composition of the melter offgas. Computerized thermodynamic computational methods are useful in predicting the sequence and products of redox reactions and in assessing individual process variations. Melter redox state can be predicted by combining monitoring of melter operating conditions, redox measurement of fused melter feed samples, and periodic redox measurement of product. Mossbauer spectroscopy, and other methods which measure Fe(II)/Fe(III) in glass, can be used to measure melter redox state. Part II develops preliminary operating limits for the vitrification of High-Level Radioactive Waste. Limits on reducing potential to preclude the accumulation of combustible gases, accumulation of sulfides and selenides, and degradation of melter components are the most critical. Problems associated with excessively oxidizing conditions, such as glass foaming and potential ruthenium volatility, are controlled when sufficient formic acid is added to adjust melter feed rheology.

  20. Groundwater transport modeling of constituents originating from the Burial Grounds Complex

    SciTech Connect (OSTI)

    Andersen, P.F.; Shupe, M.G.; Spalding, C.P. [GeoTrans, Inc., Sterling, VA (US)

    1992-10-30T23:59:59.000Z

    The Savannah River Site (SRS), operates a number of sites for the land disposal of various leachable radionuclide, organic, and inorganic wastes. Located within the General Separations Area (GSA) of SRS are the Low Level Radioactive Waste Disposal Facility (LLRWDF) and the Old Burial Ground (OBG). A portion of the LLRWDF has been designated as the Mixed Waste Management Facility (MWMF). The OBG began receiving waste in 1952 and was closed in 1974. Various wastes, including transuranic, intermediate and low level beta-gamma, and solvents, were received during this period of operation. In 1969, prior to the closing of the OBG, a portion of the MWMF/LLRWDF (the MWMF) began receiving waste. GeoTrans, Inc. was contracted by WSRC to conduct a numerical modeling study to assess groundwater flow and contaminant transport in the vicinity of the MWMF in support of an Alternate Concentration Limits demonstration for the Part B permit. The project was divided into two phases: development of a groundwater flow model of the hydrogeologic system underlying the MWMF which includes the entire GSA, and development of a solute transport model to assess migration of 19 designated constituents of concern (COCs) over a period 30 years into the future. The first phase was completed in May of 1992 and the results documented in GeoTrans (1992). That report serves as the companion volume to the present contaminant transport modeling report. The transport study is intended to develop predictions of concentration and mass flux of the 19 COCs at downgradient exposure points over the 30 year period of interest. These results are to be used in human health and ecological risk assessments which are also being performed in support of the Part B permit.

  1. Hawaii International Conference on System Sciences, January 2001, Maui, Hawaii. c 2001 IEEE An initial model for complex dynamics in electric power system blackouts

    E-Print Network [OSTI]

    Newman, David

    An initial model for complex dynamics in electric power system blackouts I. Dobson ECE Department University of electric power transmission system blackouts. The model describes opposing forces which have been conjectured to cause self-organized criticality in power system blackouts. There is a slow time scale

  2. Modeling the heat transfer in geometrically complex media with a volume source

    SciTech Connect (OSTI)

    Gurevich, M. I., E-mail: gur.m@mail.ru; Tel’kovskaya, O. V.; Chukbar, B. K.; Shkarovskiy, D. A. [National Research Center Kurchatov Institute (Russian Federation)

    2014-12-15T23:59:59.000Z

    Fuel elements produced from spent fuel are porous media with spatially varying characteristics. A hierarchical discrete structure for the numerical modeling of heat-transfer processes in media with an anisotropic geometry that is characterized by both the microscopic voids and macroscopic changes in the parameters is proposed. The basic unit of the structure at its lower level is a cell that represents the local properties of the medium. The cells have a standard interface that allows one to form three-dimensional networks of such cells. Different types of cells in the network represent macroscopic changes. The potential for parallel processing is analyzed.

  3. Plant Root Characteristics and Dynamics in Arctic Tundra Ecosystems, 1960-2012

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

    Sullivan, Paddy; Sloan, Victoria; Warren, Jeff; McGuire, Dave; Euskirchen, Eugenie; Norby, Richard; Iversen, Colleen; Walker, Anthony; Wullschleger, Stan

    A synthesis of the available literature on tundra root distribution and dynamics, and their role in key ecosystem processes in the Arctic.

  4. arctic animals-a review: Topics by E-print Network

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

    Is the central Arctic Ocean a sediment starved basin, University of Bergen, Norway d Byrd Polar Research Center, Ohio State University, USA Abstract Numerous short...

  5. arctic-breeding glaucous gulls: Topics by E-print Network

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

    stress. Norwegian Polar Institute, Polar Environmental Centre, NO-9296 Troms, Norway. Tel.: 47 7775 0500; fax: 47 Bech, Claus 8 ARCTIC Sabines Gull (Xema...

  6. E-Print Network 3.0 - arctic fox pups Sample Search Results

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

    . Mortality of arctic ... Source: Hayssen, Virginia - Department of Biological Sciences, Smith College Collection: Environmental Sciences and Ecology 2 Leashing the AlphaWolves:...

  7. Radiocarbon Content of CO 2 Respired from High Arctic Tundra in Northwest Greenland

    E-Print Network [OSTI]

    Czimczik, Claudia I; Welker, Jeffrey M

    2010-01-01T23:59:59.000Z

    J. E. , 2002: Survey of Greenland instrumental temperaturetypes in northwestern Greenland. Arctic, Antarctic, andfen ecosystem in NE-Greenland. Theoretical and Applied

  8. Adsorption desorption processes on mesoscopic pores conected to microscopic pores of complex geometry using the Ising model

    E-Print Network [OSTI]

    M. A. Balderas Altamirano; S. Cordero; G. Roman; A. Gama Goicochea

    2015-03-15T23:59:59.000Z

    In this work we report studies of nitrogen adsorption and desorption onto solid surfaces using computer simulations of the three dimensional Ising model, for systems with complex porous structures at the mesoscopic and microscopic levels. A hysteresis cycle between the adsorption and desorption processes appears and we find that its characteristics are dependent on the geometry of the pore and on the strength of the surface fluid interaction. We obtained also an average adsorption isotherm, which represents a combination of differently shaped pores, and shows robust jumps at certain values of the chemical potential as a consequence of the structures of the pores. Lastly, we compare our results with experimental data and also report the filling process of microscopic pores connected with mesopores. It is argued that these predictions are useful for researchers working on the enhanced recovery of oil and for the design of new nanomaterials, among others.

  9. Stability and Complexity in

    E-Print Network [OSTI]

    Landweber, Laura

    and complexity of a commu- nity of interacting plants and animals, following the food web as a clue. Contrary in power. Stability and Complexity in Model Ecosystems played a key role in introducing nonlinear thinking, and current threats to biodiversity have made questions about the role of ecosystem complexity

  10. Complexity penalized hydraulic fracture localization and moment tensor estimation under limited model information

    E-Print Network [OSTI]

    Ely, Gregory

    2013-01-01T23:59:59.000Z

    In this paper we present a novel technique for micro-seismic localization using a group sparse penalization that is robust to the focal mechanism of the source and requires only a velocity model of the stratigraphy rather than a full Green's function model of the earth's response. In this technique we construct a set of perfect delta detector responses, one for each detector in the array, to a seismic event at a given location and impose a group sparsity across the array. This scheme is independent of the moment tensor and exploits the time compactness of the incident seismic signal. Furthermore we present a method for improving the inversion of the moment tensor and Green's function when the geometry of seismic array is limited. In particular we demonstrate that both Tikhonov regularization and truncated SVD can improve the recovery of the moment tensor and be robust to noise. We evaluate our algorithm on synthetic data and present error bounds for both estimation of the moment tensor as well as localization...

  11. Complex particle and light fragment emission in the cascade-excitation model of nuclear reactions

    SciTech Connect (OSTI)

    Mashnik, S. G. (Stepan G.); Sierk, A. J. (Arnold J.); Gudima, K. K. (Konstantin K.)

    2002-01-01T23:59:59.000Z

    A brief description of our improvements and refinements that led from the CEM95 version of the Cascade-Exciton Model (CEM) code to CEM97 and to CEM2k is given. The increased accuracy and predictive power of the code CEM2k are shown by several examples. To describe fission and light-fragment (heavier than {sup 4}He) production, the CEM2k code has been merged with the GEM2 code of Furihata. We present some results on proton-induced fragmentation and fission reactios predicted by this extended version of CEM2k. We show that merging CEM2k with GEM2 allows us to describe many fission and fragmentation reactions in addition to the spallation reactions which are already relatively well described.

  12. Wellbore Heat Transfer Model for Wax Deposition in Permafrost Region

    E-Print Network [OSTI]

    Cui, Xiaoting

    2012-05-31T23:59:59.000Z

    Producing waxy oil in arctic area may cause wax deposited on the well wall. Since wax deposition is strongly thermal related, accurate heat transfer model is necessary in predicting and preventing wax depostion. A mathematical model was derived...

  13. Polar amplification of climate change in coupled models Received: 21 November 2002 / Accepted: 11 March 2003 / Published online: 17 June 2003

    E-Print Network [OSTI]

    Bitz, Cecilia

    the models. The range of simulated polar warming in the Arctic is from 1.5 to 4.5 times the global mean among models that the Arctic warms more than subpolar regions when subject to increasing levels hemispheres the range of warming across global climate models is considerable, with the range of warm- ing

  14. Oceanic periglacial in the evolution of the Arctic marine ecosystem

    SciTech Connect (OSTI)

    Matishov, G.G. [Russian Academy of Sciences, Murmansk (Russian Federation). Murmansk Marine Biological Inst.

    1996-12-31T23:59:59.000Z

    A study of the Arctic marine and land environment and biota is connected with the analysis of the global climatic changes and the general history of Arctic and subarctic ecological systems. Ancient glaciation not only influenced the geomorphology of landscapes, physical and chemical properties of the ocean and its seas, but also caused the global change of the morphoclimatic zonality in the ocean as a whole. Submarine and subaqual hydrological, geomorphological and biological processes on the shelves of polar and temperate latitudes had intensified especially during the melting of continental glaciers. The study of the periglacial problem consists, as a whole, in the research of the geological and biological phenomena which take place in the pelagial and the benthal outside the ice sheets and are connected with them by causal, spatial and temporal relations.

  15. Compact complex manifolds as models Main theorem Strongly minimal groups Higher rank groups Questions Groups in the theory of compact complex

    E-Print Network [OSTI]

    Scanlon, Thomas

    = {z U | f (z) = 0}. Definition The structure CCM is the multisorted structure having a sort M Questions Basic model theory of CCM · CCM eliminates quantifiers. Thomas Scanlon University of California theorem Strongly minimal groups Higher rank groups Questions Basic model theory of CCM · CCM eliminates

  16. Development of Surface Complexation Models of Cr(VI) Adsorption on Soils, Sediments and Model Mixtures of Kaolinite, Montmorillonite, ?-Alumina, Hydrous Manganese and Ferric Oxides and Goethite

    SciTech Connect (OSTI)

    Koretsky, Carla [Western Michigan University] [Western Michigan University

    2013-11-29T23:59:59.000Z

    Hexavalent chromium is a highly toxic contaminant that has been introduced into aquifers and shallow sediments and soils via many anthropogenic activities. Hexavalent chromium contamination is a problem or potential problem in the shallow subsurface at several DOE sites, including Hanford, Idaho National Laboratory, Los Alamos National Laboratory and the Oak Ridge Reservation (DOE, 2008). To accurately quantify the fate and transport of hexavalent chromium at DOE and other contaminated sites, robust geochemical models, capable of correctly predicting changes in chromium chemical form resulting from chemical reactions occurring in subsurface environments are needed. One important chemical reaction that may greatly impact the bioavailability and mobility of hexavalent chromium in the subsurface is chemical binding to the surfaces of particulates, termed adsorption or surface complexation. Quantitative thermodynamic surface complexation models have been derived that can correctly calculate hexavalent chromium adsorption on well-characterized materials over ranges in subsurface conditions, such pH and salinity. However, models have not yet been developed for hexavalent chromium adsorption on many important constituents of natural soils and sediments, such as clay minerals. Furthermore, most of the existing thermodynamic models have been developed for relatively simple, single solid systems and have rarely been tested for the complex mixtures of solids present in real sediments and soils. In this study, the adsorption of hexavalent chromium was measured as a function of pH (3-10), salinity (0.001 to 0.1 M NaNO3), and partial pressure of carbon dioxide(0-5%) on a suite of naturally-occurring solids including goethite (FeOOH), hydrous manganese oxide (MnOOH), hydrous ferric oxide (Fe(OH)3), ?-alumina (Al2O3), kaolinite (Al2Si2O5(OH)4), and montmorillonite (Na3(Al, Mg)2Si4O10(OH)2?nH2O). The results show that all of these materials can bind substantial quantities of hexavalent chromium, especially at low pH. Unexpectedly, experiments with the clay minerals kaolinite and montmorillonite suggest that hexavalent chromium may interact with these solids over much longer periods of time than expected. Furthermore, hexavalent chromium may irreversibly bind to these solids, perhaps because of oxidation-reduction reactions occurring on the surfaces of the clay minerals. More work should be done to investigate and quantify these chemical reactions. Experiments conducted with mixtures of goethite, hydrous manganese oxide, hydrous ferric oxide, ?-alumina, montmorillonite and kaolinite demonstrate that it is possible to correctly predict hexavalent chromium binding in the presence of multiple minerals using thermodynamic models derived for the simpler systems. Further, these models suggest that of the six solid considered in this study, goethite is typically the solid to which most of the hexavalent chromium will bind. Experiments completed with organic-rich and organic-poor natural sediments demonstrate that in organic-rich substrates, organic matter is likely to control uptake of the hexavalent chromium. The models derived and tested in this study for hexavalent chromium binding to ?-alumina, hydrous manganese oxide, goethite, hydrous ferric oxide and clay minerals can be used to better predict changes in hexavalent chromium bioavailability and mobility in contaminated sediments and soils.

  17. PACIFIC VENTILATION OF THE ARCTIC OCEAN'S LOWER HALOCLINE BY UPWELLING AND DIAPYCNAL MIXING OVER THE CONTINENTAL MARGIN

    E-Print Network [OSTI]

    Washington at Seattle, University of

    PACIFIC VENTILATION OF THE ARCTIC OCEAN'S LOWER HALOCLINE BY UPWELLING AND DIAPYCNAL MIXING OVER of nutrients and buoyancy to the Arctic Ocean, are thought to ventilate the Arctic's lower halocline either waters upwelled onto the shelf. Although ventilation at salinity (S) > 34 psu has previously been

  18. IGS 2000: RGPS Albedo June 15, 2001 1 Arctic sea ice albedo derived from RGPS-based

    E-Print Network [OSTI]

    Lindsay, Ron

    of Arctic pack ice ia a highly significant factor for establishing the energy balance of the ice. The netIGS 2000: RGPS Albedo June 15, 2001 1 Arctic sea ice albedo derived from RGPS-based ice thickness Geophysical Processor System (RGPS) uses sequential synthetic aperture radar images of Arctic sea ice taken

  19. Retrieval of Cloud Phase Using the Moderate Resolution Imaging Spectroradiometer Data during the Mixed-Phase Arctic Cloud Experiment

    SciTech Connect (OSTI)

    Spangenberg, D.; Minnis, P.; Shupe, M.; Uttal, T.; Poellot, M.

    2005-03-18T23:59:59.000Z

    Improving climate model predictions over Earth's polar regions requires a comprehensive knowledge of polar cloud microphysics. Over the Arctic, there is minimal contrast between the clouds and background snow surface, making it difficult to detect clouds and retrieve their phase from space. Snow and ice cover, temperature inversions, and the predominance of mixed-phase clouds make it even more difficult to determine cloud phase. Also, since determining cloud phase is the first step toward analyzing cloud optical depth, particle size, and water content, it is vital that the phase be correct in order to obtain accurate microphysical and bulk properties. Changes in these cloud properties will, in turn, affect the Arctic climate since clouds are expected to play a critical role in the sea ice albedo feedback. In this paper, the IR trispectral technique (IRTST) is used as a starting point for a WV and 11-{micro}m brightness temperature (T11) parameterization (WVT11P) of cloud phase using MODIS data. In addition to its ability to detect mixed-phase clouds, the WVT11P also has the capability to identify thin cirrus clouds overlying mixed or liquid phase clouds (multiphase ice). Results from the Atmospheric Radiation Measurement (ARM) MODIS phase model (AMPHM) are compared to the surface-based cloud phase retrievals over the ARM North Slope of Alaska (NSA) Barrow site and to in-situ data taken from University of North Dakota Citation (CIT) aircraft which flew during the Mixed-Phase Arctic Cloud Experiment (MPACE). It will be shown that the IRTST and WVT11P combined to form the AMPHM can achieve a relative high accuracy of phase discrimination compared to the surface-based retrievals. Since it only uses MODIS WV and IR channels, the AMPHM is robust in the sense that it can be applied to daytime, twilight, and nighttime scenes with no discontinuities in the output phase.

  20. Arctic ice export events and their potential impact on global climate during the late Pleistocene

    E-Print Network [OSTI]

    Darby, Dennis

    Arctic ice export events and their potential impact on global climate during the late Pleistocene export events are identified from the Laurentide and the Innuitian ice sheets, between 14 and 34 ka, the Arctic export events appear to occur prior to Heinrich events. INDEX TERMS: 4207 Oceanography: General

  1. On the Microphysical Representation of Observed Arctic Mixed-Phase Clouds

    E-Print Network [OSTI]

    Zuidema, Paquita

    On the Microphysical Representation of Observed Arctic Mixed-Phase Clouds Paquita Zuidema, Paul Lawson, Hugh Morrison U of Miami/SPEC, Inc. Boulder CO/NCAR #12;Arctic clouds are often: mixed-phase (ie. both ice + supercooled water) yet long-lasting (despite disequilibrium) #12;why? - are ice nuclei over

  2. Impact of sudden Arctic sea-ice loss on stratospheric polar ozone recovery

    E-Print Network [OSTI]

    Wirosoetisno, Djoko

    Impact of sudden Arctic sea-ice loss on stratospheric polar ozone recovery 1234567 89A64BC7DEF72B4BE647 #12;Impact of sudden Arctic sea-ice loss on stratospheric polar ozone recovery J. F. Scinocca,1. [1] We investigate the sensitivity of Northern Hemisphere polar ozone recovery to a scenario in which

  3. Revised 1/11/05 BOWHEAD WHALE (Balaena mysticetus): Western Arctic Stock

    E-Print Network [OSTI]

    and the mobile polar pack ice. There is evidence of whales following each other, even when their route does+++++ +++++++ + +++++++++ Ice Front Revised 1/11/05 BOWHEAD WHALE (Balaena mysticetus): Western in seasonally ice-covered waters of the Arctic and near-Arctic, generally north of 60(N and south of 75(N

  4. Variability of sea ice cover in the Chukchi Sea (western Arctic Ocean) during the Holocene

    E-Print Network [OSTI]

    Darby, Dennis

    of the Arctic Ocean during the last decades suggest a decrease in areal extent and thickness of its pack ice [e be tentatively attributed to global warming and raises concerns about the stability and fate of the pack ice of Arctic pack ice, which cannot be fully assessed from short-term instrumental observations alone

  5. Mechanisms of summertime upper Arctic Ocean warming and the effect on sea ice melt

    E-Print Network [OSTI]

    Zhang, Jinlun

    but occurs over a much broader area of the ice pack. Citation: Steele, M., J. Zhang, and W. Ermold (2010Mechanisms of summertime upper Arctic Ocean warming and the effect on sea ice melt Michael Steele,1 summertime upper ocean warming and sea ice melt during the 21st century in the Arctic Ocean. Our first

  6. Cloud water contents and hydrometeor sizes during the FIRE Arctic Clouds Experiment

    E-Print Network [OSTI]

    Shupe, Matthew

    of radiometers at an ice station frozen into the drifting ice pack of the Arctic Ocean. The NASA/FIRE Arctic- dependent water contents and hydrometeor sizes for all-ice and all-liquid clouds. For the spring and early summer period, all-ice cloud retrievals showed a mean particle diameter of about 60 m and ice water

  7. Future abrupt reductions in the summer Arctic sea ice Marika M. Holland,1

    E-Print Network [OSTI]

    Bitz, Cecilia

    years with considerable thinning of the ice pack [Rothrock et al., 1999; Wadhams and Davis, 2000Future abrupt reductions in the summer Arctic sea ice Marika M. Holland,1 Cecilia M. Bitz,2 12 December 2006. [1] We examine the trajectory of Arctic summer sea ice in seven projections from

  8. Impact of underwater-ice evolution on Arctic summer sea ice

    E-Print Network [OSTI]

    Worster, M. Grae

    Impact of underwater-ice evolution on Arctic summer sea ice Dirk Notz,1,4 Miles G. McPhee,2 M. Grae the simultaneous growth and ablation of a layer of ice between an under-ice melt pond and the underlying ocean. Such ``false bottoms'' are the only significant source of ice formation in the Arctic during summer. Analytical

  9. Conservative behavior of uranium vs. salinity in Arctic sea ice and brine Christelle Not a,

    E-Print Network [OSTI]

    Available online 23 December 2011 Keywords: Uranium Salinity Sea ice Brine Seawater Arctic UraniumConservative behavior of uranium vs. salinity in Arctic sea ice and brine Christelle Not a, ,1 disequilibrium The conservative behavior of uranium (U) with respect to salinity in open ocean waters is widely

  10. Be production-rate calibration for the Arctic NICOLA S E. YOUNG,1,2

    E-Print Network [OSTI]

    Briner, Jason P.

    A 10 Be production-rate calibration for the Arctic NICOLA´ S E. YOUNG,1,2 * JOERG M. SCHAEFER,1 2013; Accepted 18 April 2013 ABSTRACT: We present a Baffin Bay 10 Be production-rate calibration published 10 Be calibration datasets to develop an Arctic 10 Be production rate. Our calibration comprises

  11. ORIGINAL PAPER Sedimentary pellets as an ice-cover proxy in a High Arctic

    E-Print Network [OSTI]

    Vincent, Warwick F.

    ORIGINAL PAPER Sedimentary pellets as an ice-cover proxy in a High Arctic ice-covered lake Jessica-cover extent and dynamics on this perennially ice-covered, High Arctic lake. These pellets are interpreted growth. The pellets remain frozen in the ice until a summer or series of summers with reduced ice cover

  12. REGULAR ARTICLE Soil nitrogen cycling rates in low arctic shrub tundra

    E-Print Network [OSTI]

    Grogan, Paul

    of the soil microbial community in both ecosystems indicat- ed similar fungal dominance (epifluorescence landscape. Keywords 15 Nitrogen . Gross N mineralization . Arctic tundra . Litter. Soil microbial community). For example, remote sensing studies have characterized an increase in peak-season biomass across the Arctic

  13. JP2.3 CLOUD RADIATIVE HEATING RATE FORCING FROM PROFILES OF RETRIEVED ARCTIC CLOUD MICROPHYSICS

    E-Print Network [OSTI]

    Shupe, Matthew

    JP2.3 CLOUD RADIATIVE HEATING RATE FORCING FROM PROFILES OF RETRIEVED ARCTIC CLOUD MICROPHYSICS surface. In 1997-1998, a large multi-agency effort made the Surface Heat Budget of the Arctic (SHEBA with the ice pack in the Beaufort and Chukchi Seas for one year. Surface-based remote sensors generated

  14. ORIGINAL PAPER Arctic fisheries catches in Russia, USA, and Canada: baselines

    E-Print Network [OSTI]

    Pauly, Daniel

    years due to climate change. The Arctic is one of the last and most extensive ocean wilderness areas climate change pressures, is considerable. The United Nations Food and Agriculture Organization's (FAOORIGINAL PAPER Arctic fisheries catches in Russia, USA, and Canada: baselines for neglected

  15. The Arctic Ocean carbon sink G.A. MacGilchrist a,n

    E-Print Network [OSTI]

    Naveira Garabato, Alberto

    Carbon sequestration Biological pump a b s t r a c t We present observation based estimatesThe Arctic Ocean carbon sink G.A. MacGilchrist a,n , A.C. Naveira Garabato a , T. Tsubouchi b , S January 2014 Keywords: Arctic Ocean Dissolved inorganic carbon Carbon budget Air­sea carbon dioxide flux

  16. Duffy et al.: Arctic Tern migration over Patagonia 155 Marine Ornithology 41: 155159 (2013)

    E-Print Network [OSTI]

    Duffy, David Cameron

    Duffy et al.: Arctic Tern migration over Patagonia 155 Marine Ornithology 41: 155­159 (2013 productive offshore waters of Argentinian Patagonia. We then explore possible reasons for this behavior-ANDEAN PASSAGE OF MIGRATING ARCTIC TERNS OVER PATAGONIA DAVID CAMERON DUFFY1 , ALY MCKNIGHT2 & DAVID B. IRONS2 1

  17. Interannual variability of Arctic sea ice export into the East Greenland Current

    E-Print Network [OSTI]

    Rohling, Eelco

    Interannual variability of Arctic sea ice export into the East Greenland Current K. A. Cox,1 J. D cycle, Arctic sea ice decline, and increasing Greenland glacial melt. Here we use new d18 O data from the East Greenland Current system at Cape Farewell and Denmark Strait to determine the relative proportions

  18. Simulated Arctic atmospheric feedbacks associated with late summer sea ice anomalies

    E-Print Network [OSTI]

    Moore, John

    Simulated Arctic atmospheric feedbacks associated with late summer sea ice anomalies A. Rinke,1,2 K depend on regional and decadal variations in the coupled atmosphere-ocean-sea ice system. Citation: Rinke to investigate feedbacks between September sea ice anomalies in the Arctic and atmospheric conditions in autumn

  19. Growing season methyl bromide and methyl chloride fluxes at a sub-arctic wetland in Sweden 

    E-Print Network [OSTI]

    Hardacre, Catherine J.; Blei, Emanuel; Heal, Mathew R

    2009-01-01T23:59:59.000Z

    Methyl bromide and methyl chloride fluxes were measured at several sites in a sub-arctic wetland near Abisko, Sweden (68°28?N 18°49?E) throughout the 2008 growing season. Averaged over 92 flux measurements the sub-arctic wetland was found to be a...

  20. Climate warming will be particularly intense over the Arctic and several observations

    E-Print Network [OSTI]

    Strong, Kimberly

    -rein- forced research ship Mirai. The icebreaker Oden supports Sweden's program. Even China is now deploying appointed by the Natural Sciences and Engineering Research Council (NSERC) and the Social Sciences and Hu Canada Closing Arctic Ozone Observatory 6 Exploring for Gas Hydrate in the Arctic 9 Book Review: Writing

  1. Moisture budget of the Arctic atmosphere from TOVS satellite data David G. Groves

    E-Print Network [OSTI]

    Francis, Jennifer

    and radiative heating of the atmosphere. These, in turn, affect surface temperature, ice growth and melt and hemispheric atmospheric processes affect the Arctic Ocean. The lack of humidity data over the Arctic Ocean. Our method yields an average annual net precipitation of 15.1 cm yrÀ1 over the polar cap (poleward

  2. Melting of small Arctic ice caps observed from ERS scatterometer time series

    E-Print Network [OSTI]

    Smith, Laurence C.

    Melting of small Arctic ice caps observed from ERS scatterometer time series Laurence C. Smith,1 of melt onset can be observed over small ice caps, as well as the major ice sheets and multi-year sea ice for 14 small Arctic ice caps from 1992­2000. Interannual and regional variability in the timing of melt

  3. The Arctic Oscillation, climate change and the effects on precipitation in Israel

    E-Print Network [OSTI]

    Daniel, Rosenfeld

    in the Mediterranean basin. © 2013 Elsevier B.V. All rights reserved. Keywords: Climate change Arctic Oscillation) investigated the effect of climate change on water resources of Eastern Mediterranean and Middle East regionThe Arctic Oscillation, climate change and the effects on precipitation in Israel Amir Givati b

  4. U.S. Arctic Research Policy: What do we need to know now?

    E-Print Network [OSTI]

    Kuligowski, Bob

    ;11 September 2007 Arctic ice retreat ­ minimum coverage and thickness #12;Carbon dioxide climbs #12;Methane: mitigation, adaptation, Arctic feedbacks, alternative energy, sequestration, Black Carbon Task Force · Involve indigenous communities in decisions · Enhance scientific monitoring and research into local

  5. Aerosol Effects on Cloud Emissivity and Surface Longwave Heating in the Arctic TIMOTHY J. GARRETT1,*

    E-Print Network [OSTI]

    ) studies show that in the Arctic cloud cover generally acts to warm the surface, while coolingAerosol Effects on Cloud Emissivity and Surface Longwave Heating in the Arctic TIMOTHY J. GARRETT1 in the atmosphere tend to increase the reflectance of solar (shortwave) radiation from water clouds, which can lead

  6. Arctic catastrophes in an idealized sea ice model Ian Eisenman

    E-Print Network [OSTI]

    Eisenman, Ian

    thermodynamics, varying open water fraction, an energy balance atmosphere, and scalable CO2. We find that summer.e., reflectiveness) between sea ice and the open water that is exposed when it melts. Bare or snow-covered sea ice reflects most sunlight back to space, while the dark ocean surface absorbs most incident light. Global

  7. Complex Dynamics

    E-Print Network [OSTI]

    Complex Dynamics Bernardo Da Costa, Koushik Ramachandran, Jingjing Qu, and I had a two semester learning seminar in complex analysis and potential ...

  8. Reformulated Gasoline Complex Model

    Gasoline and Diesel Fuel Update (EIA)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative1 First Use of Energy for All Purposes (Fuel and Nonfuel), 2002; Level: National5Sales for On-Highway4,1,50022,3,,,,6,1,9,1,50022,3,,,,6,1,Decade Energy I I' a evie _ =_ In7, 20116,650.0622Product:Refiners Switch to

  9. Exponential Random Simplicial Complexes

    E-Print Network [OSTI]

    Zuev, Konstantin; Krioukov, Dmitri

    2015-01-01T23:59:59.000Z

    Exponential random graph models have attracted significant research attention over the past decades. These models are maximum-entropy ensembles under the constraints that the expected values of a set of graph observables are equal to given values. Here we extend these maximum-entropy ensembles to random simplicial complexes, which are more adequate and versatile constructions to model complex systems in many applications. We show that many random simplicial complex models considered in the literature can be casted as maximum-entropy ensembles under certain constraints. We introduce and analyze the most general random simplicial complex ensemble $\\mathbf{\\Delta}$ with statistically independent simplices. Our analysis is simplified by the observation that any distribution $\\mathbb{P}(O)$ on any collection of objects $\\mathcal{O}=\\{O\\}$, including graphs and simplicial complexes, is maximum-entropy under the constraint that the expected value of $-\\ln \\mathbb{P}(O)$ is equal to the entropy of the distribution. W...

  10. Simulations of Arctic Mixed-Phase Clouds in Forecasts with CAM3 and AM2 for M-PACE

    SciTech Connect (OSTI)

    Xie, Shaocheng; Boyle, James; Klein, Stephen A.; Liu, Xiaohong; Ghan, Steven J.

    2008-02-29T23:59:59.000Z

    Simulations of mixed-phase clouds in short-range forecasts with the National Center for Atmospheric Research Community Atmosphere Model version 3 (CAM3) and the Geophysical Fluid Dynamics Laboratory (GFDL) climate model (AM2) for the Mixed-Phase Arctic Cloud Experiment (M-PACE) are performed under the DOE CCPP-ARM Parameterization Testbed (CAPT), which initializes the climate models with analysis data produced from numerical weather prediction (NWP) centers. It is shown that CAM3 significantly underestimates the observed boundary layer mixed-phase clouds and cannot realistically simulate the variations with temperature and cloud height of liquid water fraction in the total cloud condensate based an oversimplified cloud microphysical scheme. In contrast, AM2 reasonably reproduces the observed boundary layer clouds while its clouds contain much less cloud condensate than CAM3 and the observations. Both models underestimate the observed cloud top and base for the boundary layer clouds. The simulation of the boundary layer mixed-phase clouds and their microphysical properties is considerably improved in CAM3 when a new physically based cloud microphysical scheme is used. The new scheme also leads to an improved simulation of the surface and top of the atmosphere longwave radiative fluxes in CAM3. It is shown that the Bergeron-Findeisen process, i.e., the ice crystal growth by vapor deposition at the expense of coexisting liquid water, is important for the models to correctly simulate the characteristics of the observed microphysical properties in mixed-phase clouds. Sensitivity tests show that these results are not sensitive to the analysis data used for model initializations. Increasing model horizontal resolution helps capture the subgrid-scale features in Arctic frontal clouds but does not help improve the simulation of the single-layer boundary layer clouds. Ice crystal number density has large impact on the model simulated mixed-phase clouds and their microphysical properties and needs to be accurately represented in climate models.

  11. 4, 50455074, 2004 Arctic ozone loss in

    E-Print Network [OSTI]

    Paris-Sud XI, Université de

    , Germany 4 Central Aerological Observatory (CAO), Moscow, Russia 5 Institute of Atmospheric Sciences and Climate (ISAC), Italian National Research Council, Bologna, Italy 6 Alfred Wegener Institute, Potsdam changes to the CTM have improved the model's ability to reproduce polar chemical and dynamical processes.5

  12. ARM - Field Campaign - FIRE-Arctic Cloud Experiment/SHEBA

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

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative1 First Use of Energy for All Purposes (Fuel and Nonfuel), 2002; Level: National5Sales for4,645U.S. DOE Office of ScienceandMesa del(ANL-IN-03-032)8LigovCampaignsCLEX-5 CampaignSP2govCampaignsFIRE-Arctic Cloud

  13. ARM - Field Campaign - Mixed-Phase Arctic Cloud Experiment

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

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative1 First Use of Energy for All Purposes (Fuel and Nonfuel), 2002; Level: National5Sales for4,645U.S. DOE Office of ScienceandMesa- Polarization Diversity Lidar (PDL)govCampaignsMixed-Phase Arctic Cloud Experiment

  14. ARM - Publications: Science Team Meeting Documents: An Arctic Springtime

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

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative1 First Use of Energy for All Purposes (Fuel and Nonfuel), 2002; Level: National5Sales for4,645U.S. DOE Office of ScienceandMesa-Anomalous Radiative AbsorptionARM InArctic Facility for Atmospheric Remote

  15. Understanding complex Earth systems: volatile metabolites as microbial ecosystem proxies and student conceptual model development of coastal eutrophication

    E-Print Network [OSTI]

    McNeal, Karen Sue

    2009-05-15T23:59:59.000Z

    research strands which contribute to the scientific and pedagogical understanding of complex Earth systems. In the first strand, a method that characterizes volatile organic compounds (VOCs) as ecological proxies of soil microbial ecosystems was validated...

  16. Introduction Complexity &

    E-Print Network [OSTI]

    Bonet, Blai

    Introduction Basics Complexity & Expressivity Analysis Techniques Special Classes of Nets Conclusion Petri Nets (for Planners) B. Bonet, P. Haslum ... from various places ... ICAPS 2011 #12;Introduction Basics Complexity & Expressivity Analysis Techniques Special Classes of Nets Conclusion

  17. Distribution kinetics of dietary methylmercury in the arctic charr (Salvelinus alpinus)

    SciTech Connect (OSTI)

    Ribeiro, C.A.O. [Univ. Federal do Parana, Curitiba, Parana (Brazil). Dept. de Biologia Celular] [Univ. Federal do Parana, Curitiba, Parana (Brazil). Dept. de Biologia Celular; Rouleau, C. [Inst. Maurice-Lamontagne, Mont-Joli, Quebec (Canada)] [Inst. Maurice-Lamontagne, Mont-Joli, Quebec (Canada); Pelletier, E.; Audet, C. [Univ. du Quebec, Rimouski, Quebec (Canada). INRS-Oceanologie] [Univ. du Quebec, Rimouski, Quebec (Canada). INRS-Oceanologie; Tjaelve, H. [Swedish Univ. of Agricultural Sciences, Uppsala (Sweden)] [Swedish Univ. of Agricultural Sciences, Uppsala (Sweden)

    1999-03-15T23:59:59.000Z

    The authors fed immature 1+ arctic charr with a single dose of methyl[{sup 203}Hg]mercury (MeHg) and quantified distribution kinetics with a new and simple three-compartment caternary model having well-perfused viscera and blood as the central compartment (VB), whereas gut (G) and the rest of body (R) constituted the peripheral compartments. The model accurately described distribution kinetics of MeHg in the fish, using either data of MeHg content in compartments or blood concentration data. Despite the known fast translocation of MeHg between binding sites at the molecular level, its translocation rate between compartments was surprisingly slow, 27 days being needed to complete 95% of the transfer from gut to blood and 48 days for the subsequent transfer to compartment R. This probably results from a limitation of the stepwise transfer rate of MeHg from red blood cells, which contain most of blood MeHg, to plasma and then to tissues due to low plasmatic concentration of small mobile sulfhydryl ligands. The model presented is a convenient tool that could be used to compare the fate of MeHg and other organometals, such as butyltins and alkylleads, in various aquatic and terrestrial animal species.

  18. Arctic Energy Technology Development Laboratory (Part 2)

    SciTech Connect (OSTI)

    See OSTI ID Number 960443

    2008-12-31T23:59:59.000Z

    Methane (CH{sub 4}) in natural gas is a major energy source in the U.S., and is used extensively on Alaska's North Slope, including the oilfields in Prudhoe Bay, the community of Barrow, and the National Petroleum Reserve, Alaska (NPRA). Smaller villages, however, are dependent on imported diesel fuel for both power and heating, resulting in some of the highest energy costs in the U.S. and crippling local economies. Numerous CH{sub 4} gas seeps have been observed on wetlands near Atqasuk, Alaska (in the NPRA), and initial measurements have indicated flow rates of 3,000-5,000 ft{sup 3} day{sup -1} (60-100 kg CH{sub 4} day{sup -1}). Gas samples collected in 1996 indicated biogenic origin, although more recent sampling indicated a mixture of biogenic and thermogenic gas. In this study, we (1) quantified the amount of CH{sub 4} generated by several seeps and evaluated their potential use as an unconventional gas source for the village of Atqasuk; (2) collected gas and analyzed its composition from multiple seeps several miles apart to see if the source is the same, or if gas is being generated locally from isolated biogenic sources; and (3) assessed the potential magnitude of natural CH{sub 4} gas seeps for future use in climate change modeling.

  19. Mobilization pathways of organic carbon from permafrost to arctic rivers in a changing climate

    E-Print Network [OSTI]

    Guo, Laodong

    and subarctic river waters is dominated by contemporary sour- ces [Benner et al., 2004; Guo and Macdonald, 2006 in arctic rivers should then become older, reflecting the age of that reservoir [Schell and Ziemann, 1983

  20. Assessing the Predictability of the Beaufort Sea Minimum Ice Extent in a Changing Arctic Climate Regime

    E-Print Network [OSTI]

    Quirk, Laura Marie

    2014-04-25T23:59:59.000Z

    Understanding the climatic drivers of changes in sea ice extent in the Arctic has become increasingly important as record minima in the September sea ice extent continue to be reached. This research therefore addresses the question of which synoptic...

  1. Metal Analysis of Scales Taken from Arctic Grayling A. P. Farrell,1

    E-Print Network [OSTI]

    Farrell, Anthony P.

    scales taken from Arctic grayling using laser ablation­induc- tively coupled plasma mass spectrometry (LA of the scales. Ten elements (Mg, Ca, Ni, Zn, As, Se, Cd, Sb, Hg, and Pb) were measured in 10 to 16 ablation

  2. Building skills : a construction trades training facility for the eastern Canadian Arctic

    E-Print Network [OSTI]

    Roszler, Sarah Katherine, 1977-

    2005-01-01T23:59:59.000Z

    On April 1, 1999, the Inuit of the Eastern Canadian Arctic achieved sovereignty over a new territory, Nunavut, envisioning economic self-reliance, political self-determination, and renewal of confidence in Inuit community. ...

  3. A Micro-Grid Simulator Tool (SGridSim) using Effective Node-to-Node Complex Impedance (EN2NCI) Models

    SciTech Connect (OSTI)

    Udhay Ravishankar; Milos manic

    2013-08-01T23:59:59.000Z

    This paper presents a micro-grid simulator tool useful for implementing and testing multi-agent controllers (SGridSim). As a common engineering practice it is important to have a tool that simplifies the modeling of the salient features of a desired system. In electric micro-grids, these salient features are the voltage and power distributions within the micro-grid. Current simplified electric power grid simulator tools such as PowerWorld, PowerSim, Gridlab, etc, model only the power distribution features of a desired micro-grid. Other power grid simulators such as Simulink, Modelica, etc, use detailed modeling to accommodate the voltage distribution features. This paper presents a SGridSim micro-grid simulator tool that simplifies the modeling of both the voltage and power distribution features in a desired micro-grid. The SGridSim tool accomplishes this simplified modeling by using Effective Node-to-Node Complex Impedance (EN2NCI) models of components that typically make-up a micro-grid. The term EN2NCI models means that the impedance based components of a micro-grid are modeled as single impedances tied between their respective voltage nodes on the micro-grid. Hence the benefit of the presented SGridSim tool are 1) simulation of a micro-grid is performed strictly in the complex-domain; 2) faster simulation of a micro-grid by avoiding the simulation of detailed transients. An example micro-grid model was built using the SGridSim tool and tested to simulate both the voltage and power distribution features with a total absolute relative error of less than 6%.

  4. Real-time processing of remote sensor data as applied to Arctic ice classification

    E-Print Network [OSTI]

    Permenter, James Austin

    1973-01-01T23:59:59.000Z

    REAL-TIME PROCESSING OF REMOTE SENSOR DATA AS APPLIED TO ARCTIC ICE CLASSIFICATION A Thesis by JAMES AUSTIN PERMENTER partial ! Submitted to the Graduate College of Texas A)M University in fulfillment of the requirement for the degree... of MASTER OF SCIENCE December 1973 Major Subject: Electrical Engineering REAL-TIME PROCESSING OF REMOTE SENSOR DATA AS APPLIED TO ARCTIC ICE CLASSIFICATION A Thesis by James Austin Permenter Approved as to style and content by: ] ( rman of Commi...

  5. Generating Structurally Complex Test Cases by Data Mutation: A Case Study of Testing an Automated Modelling Tool

    E-Print Network [OSTI]

    Zhu, Hong

    - 1 - Generating Structurally Complex Test Cases by Data Mutation: A Case Study of Testing Brookes University, Oxford OX33 1HX, UK Email: hzhu@brookes.ac.uk ABSTRACT Generation of adequate test cases is difficult and expensive, especially for testing software systems whose input is structurally

  6. JOURNAL OF INFORMATION SCIENCE AND ENGINEERING 28, 689-704 (2012) The Complexity of GARCH Option Pricing Models

    E-Print Network [OSTI]

    Lyuu, Yuh-Dauh

    2012-01-01T23:59:59.000Z

    JOURNAL OF INFORMATION SCIENCE AND ENGINEERING 28, 689-704 (2012) 689 The Complexity of GARCH computational over- head. In fact, raising n makes the popular Ritchken-Trevor tree under non-linear GARCH that LGARCH, AGARCH, GJR-GARCH, TS-GARCH and TGARCH share the same properties as NGARCH. The theoretical

  7. Research on the seasonal snow of the Arctic Slope

    SciTech Connect (OSTI)

    Benson, C.S.

    1988-01-01T23:59:59.000Z

    The original objectives of this research included a regional study of snow on the entire Arctic Slope. During the first year the scope was restricted to the R{sub 4}D area. In the second and third years the primary focus was also on the R{sub 4}D area,but measurements were made at Prudhoe Bay, Atgasuk and Wainwright to determine the flux of wind-blown snow on a wider scale. Additional broadening of scope was discussed at the San Diego R{sub 4}D meetings in April 1986 and 1987 and at the extrapolation workshop held at Penn State University in Spring 1987. The broadening of scope has also included detailed studies of chemistry and controls exerted by large-scale advection of air masses on the longwave, thermal IR, and radiation. The latter phenomena are critical in initiating snowmelt.

  8. 90 4,000 Meters under the Ice The Arctic is one of the habitats undergoing the most

    E-Print Network [OSTI]

    PlanckResearch 89 RUSSIA Special RUSSIA Special #12;#12;TEXT MAREN EMMERICH The Arctic is one of the habitats

  9. A systems-theoretic security model for large scale, complex systems applied to the US air transportation system

    E-Print Network [OSTI]

    Laracy, Joseph R. (Joseph Raymond)

    2007-01-01T23:59:59.000Z

    Classical risk-based or game-theoretic security models rely on assumptions from reliability theory and rational expectations economics that are not applicable to security threats. Additionally, these models suffer from ...

  10. A Model pH Induced Drug-Delivery System Based on Poly(methacrylic acid) and its Interpolymer complex

    E-Print Network [OSTI]

    Murugan, K Durai; Natarajan, P

    2015-01-01T23:59:59.000Z

    The dynamics and structural aspects of polymethacrylic acid bound rhodamine-123 (PMAA-R123) and its interpolymer complex with poly(vinylpyrrolidone) were investigated and the results show that these complexes have potential for use as drug-delivery system under physiological conditions. The time resolved fluorescence anisotropy decay of PMAA-R123 at different pH exhibits an associated anisotropy decay behavior characteristic of two different environments experienced by the fluorophore and decays with one shorter and another longer lifetime components. The anisotropy decay retains normal bi-exponential behavior under neutral pH. Fluorescence correlation spectroscopic investigation reveals that the attached fluorophore undergoes hydrolysis under basic condition which results in the release of the fluorophore from the polymer backbone. Shrinkage in the hydrodynamic radius of PMAA is observed on addition of the complementary polymer PVP which is attributed to the formation compact solubilised nanoparticle like ag...

  11. Evaluation of Mixed-Phase Cloud Parameterizations in Short-Range Weather Forecasts with CAM3 and AM2 for Mixed-Phase Arctic Cloud Experiment

    SciTech Connect (OSTI)

    Xie, S; Boyle, J; Klein, S; Liu, X; Ghan, S

    2007-06-01T23:59:59.000Z

    By making use of the in-situ data collected from the recent Atmospheric Radiation Measurement Mixed-Phase Arctic Cloud Experiment, we have tested the mixed-phase cloud parameterizations used in the two major U.S. climate models, the National Center for Atmospheric Research Community Atmosphere Model version 3 (CAM3) and the Geophysical Fluid Dynamics Laboratory climate model (AM2), under both the single-column modeling framework and the U.S. Department of Energy Climate Change Prediction Program-Atmospheric Radiation Measurement Parameterization Testbed. An improved and more physically based cloud microphysical scheme for CAM3 has been also tested. The single-column modeling tests were summarized in the second quarter 2007 Atmospheric Radiation Measurement metric report. In the current report, we document the performance of these microphysical schemes in short-range weather forecasts using the Climate Chagne Prediction Program Atmospheric Radiation Measurement Parameterizaiton Testbest strategy, in which we initialize CAM3 and AM2 with realistic atmospheric states from numerical weather prediction analyses for the period when Mixed-Phase Arctic Cloud Experiment was conducted.

  12. Kinetic Modeling of Halogen-Based Plasma Etching of Complex Oxide Films and its Application to Predictive Feature Profile Simulation

    E-Print Network [OSTI]

    Marchack, Nathan

    2012-01-01T23:59:59.000Z

    model for Si etching by fluorocarbon plasmas." Journal Ofwith inductively coupled fluorocarbon plasmas." Journal ofwith inductively coupled fluorocarbon plasmas." Journal of

  13. Published by the Arctic Research Consortium of the United States 3535 College Road Suite 101 Fairbanks, AK 99709 Arctic Research at the University of Northern British Columbia

    E-Print Network [OSTI]

    Dery, Stephen

    · Fairbanks, AK 99709 Arctic Research at the University of Northern British Columbia Establishedin1994 Columbia Prince George Campus 3333 University Way Prince George, BC V2N 4Z9 Canada 250-960-5555 sderywithconsiderablepublicendorsementandenthusiasm,theUniver- sity of Northern British Columbia (UNBC) has grown into one of Canada's premier

  14. Near UV atmospheric absorption measurements of column abundances during Airborne Arctic Stratospheric Expedition, January-February 1989: 3. BrO observations

    SciTech Connect (OSTI)

    Wahner, A.; Callies, J.; Dorn, H.P.; Platt, U.; Schiller, C. (Kernforschungsanlage Juelich (West Germany))

    1990-03-01T23:59:59.000Z

    Column abundances of BrO were measured during the Airborne Arctic Stratospheric Expedition from January 6 to February 9, 1989 by near UV absorption spectroscopy. BrO was detected during early flights by scattered sunlight observations during twilight and direct moon light observations during the night. The daytime vertical column abundances of BrO varied between 2 {times} 10{sup 13} cm{sup {minus}2} and 13 {times} 10{sup 13} cm{sup {minus}2} and are consistent with observed OClO column abundances and chemical model calculations. The nighttime presence of BrO suggests different vertical profiles of BrO and ClO.

  15. Published in: Annals of Glaciology, vol. 33, pp. 194-200, 2001 Indirect measurements of the mass balance of summer Arctic sea

    E-Print Network [OSTI]

    Eicken, Hajo

    of summer ablation are of great importance in determining the overall mass balance of the Arctic ice pack in determining the state of the Arctic ice pack. Measurements of annual loss and gain of ice mass are required balance of summer Arctic sea ice with an electromagnetic induction technique H. EICKEN Geophysical

  16. Dynamics of Arctic and Sub-Arctic Climate and Atmospheric Circulation: Diagnosis of Mechanisms and Model Biases Using data Assimilation

    SciTech Connect (OSTI)

    Sumant Nigam

    2013-02-05T23:59:59.000Z

    These five publications are summarized: Key role of the Atlantic Multidecadal Oscillation in 20th century drought and wet periods over the Great Plains; A Sub-Seasonal Teleconnection Analysis: PNA Development and Its Relationship to the NAO; AMO's Structure and Climate Footprint in Observations and IPCC AR5 Climate Simulations; The Atlantic Multidecadal Oscillation in 20th Century Climate Simulations: Uneven Progress from CMIP3 to CMIP5; and Tropical Atlantic Biases in CCSM4.

  17. Critical mechanisms for the formation of extreme arctic sea-ice extent in the summers of 2007 and 1996

    E-Print Network [OSTI]

    Dong, Xiquan

    deformation on top of the long-term thinning of an Arctic ice pack that had become more dominated by seasonalCritical mechanisms for the formation of extreme arctic sea-ice extent in the summers of 2007 system, the largest year-to-year variation in sea-ice extent (SIE) has occurred in the Laptev, East

  18. The 2007 Bering Strait Oceanic Heat Flux and anomalous Arctic Sea-ice Retreat Rebecca A. Woodgate*, Tom Weingartner

    E-Print Network [OSTI]

    where heat carried by northward flowing PW weakens the ice-pack thereby promoting more sea-ice motionThe 2007 Bering Strait Oceanic Heat Flux and anomalous Arctic Sea-ice Retreat Rebecca A. Woodgate Abstract: To illuminate the role of Pacific Waters in the 2007 Arctic sea-ice retreat, we use observational

  19. UiT The Arctic University of Norway Fakultet for biovitenskap, fiskeri og konomi -Inst. for arktisk og marin biologi

    E-Print Network [OSTI]

    Uppsala Universitet

    UiT The Arctic University of Norway Fakultet for biovitenskap, fiskeri og økonomi - Inst/616 The Faculty of Biosciences, Fishery and Economics, UiT The Arctic University of Norway has a PhD position and participate in field work in Norway and Russia. The candidate must have a god command of written and spoken

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

    E-Print Network [OSTI]

    Brooks, Ian M.

    A transitioning Arctic surface energy budget: the impacts of solar zenith angle, surface albedo surface and sea-ice energy budgets were measured near 87.5°N during the Arctic Summer Cloud Ocean Study regimes, characterized by varying cloud, thermody- namic and solar properties. An initial warm, melt

  1. Arctic-Winter Climatology and Radiative Effects of Clouds and Aerosols Based on Lidar and Radar Measurements at PEARL

    E-Print Network [OSTI]

    Eloranta, Edwin W.

    Arctic-Winter Climatology and Radiative Effects of Clouds and Aerosols Based on Lidar and Radar Atmospheric Radiative Transfer (SBDART) code. Results on the climatology and radiative effects of clouds, arctic regions are the site of interactions between aerosols, clouds, radiation and precipitations

  2. Interannual Variations of Arctic Cloud Types in Relation to Sea Ice RYAN EASTMAN AND STEPHEN G. WARREN

    E-Print Network [OSTI]

    Hochberg, Michael

    longwave cloud radiative effect (CRE), sug- gesting that infrared radiation emitted toward the surface and cloud temperatures greater than 2318C. Cloud radiative effect over the Arctic likely varies seasonally of clouds have different effects on sea ice. Visual cloud reports from land and ocean regions of the Arctic

  3. Abstract--Modelling and control of gas turbines (GTs) have always been a controversial issue because of the complex

    E-Print Network [OSTI]

    Sainudiin, Raazesh

    be utilized as main mechanical drivers for large pumps, compressors, generators or impellers. In a jet engine detection, trouble shooting, etc. To make a model, some important basic factors should be considered. GT

  4. Magnetic properties of a diferrous-water complex and ligands for modeling the active site of MMOH

    E-Print Network [OSTI]

    Kelly, Amy E. (Amy Elizabeth), 1980-

    2004-01-01T23:59:59.000Z

    Chapter 1: The Importance of Modeling Diiron Sites in Nature.There are a variety of metalloenzymes that have nearly identical carboxylate-bridged diiron active sites. An example is sMMOH, an enzyme that catalyzes the ...

  5. Renewable Resources: a national catalog of model projects. Volume 2. Mid-American Solar Energy Complex Region

    SciTech Connect (OSTI)

    None

    1980-07-01T23:59:59.000Z

    This compilation of diverse conservation and renewable energy projects across the United States was prepared through the enthusiastic participation of solar and alternate energy groups from every state and region. Compiled and edited by the Center for Renewable Resources, these projects reflect many levels of innovation and technical expertise. In many cases, a critique analysis is presented of how projects performed and of the institutional conditions associated with their success or failure. Some 2000 projects are included in this compilation; most have worked, some have not. Information about all is presented to aid learning from these experiences. The four volumes in this set are arranged in state sections by geographic region, coinciding with the four Regional Solar Energy Centers. The table of contents is organized by project category so that maximum cross-referencing may be obtained. This volume includes information on the Mid-American Solar Energy Complex Region. (WHK)

  6. Use of Probabilistic Relational Model (PRM) for Dependability Analysis of Complex G. Medina Oliva, P. Weber, E. Levrat, B. Iung

    E-Print Network [OSTI]

    Paris-Sud XI, Université de

    .uhp-nancy.fr,{philippe.weber}@esstin.uhp-nancy.fr Abstract: This paper proposes a methodology to develop a decision-making aid tool which purpose related to risk analysis and dependability which allow to forecast the gaps between nominal and non of an approach to formalize a model required to evaluate risk analysis, maintenance and dependability

  7. Achieving Structural and Composable Modeling of Complex Systems David I. August Sharad Malik Li-Shiuan Peh

    E-Print Network [OSTI]

    employed to- day is hand-writing monolithic simulators in sequential pro- gramming languages such as C or C of failure. ¯ Rapid Reuse. Monolithic simulator tools tend to be "one-off" items often rewritten from scratch for each project. Models of the same single component may be written many times to fit each simulation

  8. Non-nuclear submarine tankers could cost-effectively move Arctic oil and gas

    SciTech Connect (OSTI)

    Kumm, W.H.

    1984-03-05T23:59:59.000Z

    Before the advent of nuclear propulsion for U.S. Navy submarines, fuel cells were considered to be the next logical step forward from battery powered submarines which required recharging. But with the launching of the USS Nautilus (SSN-571) in 1954, the development of fuel-cell propulsion was sidelined by the naval community. Nearly 30 years later fuel-cell propulsion on board submarines is actually more cost-effective than the use of nuclear propulsion. In the Artic Ocean, the use of the submarine tanker has long been considered commercially appropriate because of the presence of the polar ice cap, which inhibits surface ship transport. The technical difficulty and high operating cost of Arctic icebreaking tankers are strong arguments in favor of the cheaper, more efficient submarine tanker. Transiting under the polar ice cap, the submarine tanker is not an ''Arctic'' system, but merely a submerged system. It is a system usable in any ocean around the globe where sufficient depth exists (about 65% of the global surface). Ice breakers are another story; their design only makes them useful for transit through heavy sea ice in coastal environments. Used anywhere else, such as in the open ocean or at the Arctic ice cap, they are not a cost-effective means of transport. Arctic sea ice conditions require the Arctic peculiar icebreaking tanker system to do the job the hard way-on the surface. But on the other hand, Arctic sea ice conditions are neatly set aside by the submarine tanker, which does it the energy-efficient, elegant way submerged. The submarine tanker is less expensive to build, far less expensive to operate, and does not need to be nuclear propelled.

  9. arctic ocean expedition: Topics by E-print Network

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

    oceans contain a complex mixture of micro Bermingham, Eldredge 5 Integrated Ocean Drilling Program Expedition 301 Scientific Prospectus Geosciences Websites Summary: .tamu.edu...

  10. arctic vegetation damage: Topics by E-print Network

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

    gradient. Here we examine the complex interrelationships between patterned ground, climate, vegetation and soil along a north-south transect through all five bioclimate...

  11. An experimental investigation of a simple model simulation of a complex non-uniform beam (aircraft) vibration

    E-Print Network [OSTI]

    Hardin, William David

    1966-01-01T23:59:59.000Z

    CPM OR 205. 146 RAD. /SEC. . 08 NODES . 06 e 04 '0 O 02 0 z . 02 O z IP ?. 04 EX CI TER LOCA TI ON -. 06 -. 08 Station 10 FIGURE 12. SECOND MODE SHAPE CURVE OF THE MODEL BEAM 5. 0 4. 0 3. 0 PROTOTYPE Q MODEL 2. 0 1, 0 n 0 -1... obtained by utilizing the Buckingham "Pi Theorem" (8) is: ?. ER(-~J L- (x)j F'L T = IT j IFL 3 IFT L j ~L J [2] Equating exponents of the three dimensions produces: F. O = a+b L:0 = Za-2b+c T:0 = -1+Zb. Solving yields a = -s, b=z, and c=Z...

  12. Algorithmic folding complexity

    E-Print Network [OSTI]

    Cardinal, Jean

    2009-01-01T23:59:59.000Z

    How do we most quickly fold a paper strip (modeled as a line) to obtain a desired mountain-valley pattern of equidistant creases (viewed as a binary string)? Define the folding complexity of a mountain-valley string as the ...

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

    E-Print Network [OSTI]

    Hulme, Mike

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

  14. Spin densities from subsystem density-functional theory: Assessment and application to a photosynthetic reaction center complex model

    SciTech Connect (OSTI)

    Solovyeva, Alisa [Gorlaeus Laboratories, Leiden Institute of Chemistry, Leiden University, P.O. Box 9502, 2300 RA Leiden (Netherlands); Technical University Braunschweig, Institute for Physical and Theoretical Chemistry, Hans-Sommer-Str. 10, 38106 Braunschweig (Germany); Pavanello, Michele [Gorlaeus Laboratories, Leiden Institute of Chemistry, Leiden University, P.O. Box 9502, 2300 RA Leiden (Netherlands); Neugebauer, Johannes [Technical University Braunschweig, Institute for Physical and Theoretical Chemistry, Hans-Sommer-Str. 10, 38106 Braunschweig (Germany)

    2012-05-21T23:59:59.000Z

    Subsystem density-functional theory (DFT) is a powerful and efficient alternative to Kohn-Sham DFT for large systems composed of several weakly interacting subunits. Here, we provide a systematic investigation of the spin-density distributions obtained in subsystem DFT calculations for radicals in explicit environments. This includes a small radical in a solvent shell, a {pi}-stacked guanine-thymine radical cation, and a benchmark application to a model for the special pair radical cation, which is a dimer of bacteriochlorophyll pigments, from the photosynthetic reaction center of purple bacteria. We investigate the differences in the spin densities resulting from subsystem DFT and Kohn-Sham DFT calculations. In these comparisons, we focus on the problem of overdelocalization of spin densities due to the self-interaction error in DFT. It is demonstrated that subsystem DFT can reduce this problem, while it still allows to describe spin-polarization effects crossing the boundaries of the subsystems. In practical calculations of spin densities for radicals in a given environment, it may thus be a pragmatic alternative to Kohn-Sham DFT calculations. In our calculation on the special pair radical cation, we show that the coordinating histidine residues reduce the spin-density asymmetry between the two halves of this system, while inclusion of a larger binding pocket model increases this asymmetry. The unidirectional energy transfer in photosynthetic reaction centers is related to the asymmetry introduced by the protein environment.

  15. CFD [computational fluid dynamics] And Safety Factors. Computer modeling of complex processes needs old-fashioned experiments to stay in touch with reality.

    SciTech Connect (OSTI)

    Leishear, Robert A.; Lee, Si Y.; Poirier, Michael R.; Steeper, Timothy J.; Ervin, Robert C.; Giddings, Billy J.; Stefanko, David B.; Harp, Keith D.; Fowley, Mark D.; Van Pelt, William B.

    2012-10-07T23:59:59.000Z

    Computational fluid dynamics (CFD) is recognized as a powerful engineering tool. That is, CFD has advanced over the years to the point where it can now give us deep insight into the analysis of very complex processes. There is a danger, though, that an engineer can place too much confidence in a simulation. If a user is not careful, it is easy to believe that if you plug in the numbers, the answer comes out, and you are done. This assumption can lead to significant errors. As we discovered in the course of a study on behalf of the Department of Energy's Savannah River Site in South Carolina, CFD models fail to capture some of the large variations inherent in complex processes. These variations, or scatter, in experimental data emerge from physical tests and are inadequately captured or expressed by calculated mean values for a process. This anomaly between experiment and theory can lead to serious errors in engineering analysis and design unless a correction factor, or safety factor, is experimentally validated. For this study, blending times for the mixing of salt solutions in large storage tanks were the process of concern under investigation. This study focused on the blending processes needed to mix salt solutions to ensure homogeneity within waste tanks, where homogeneity is required to control radioactivity levels during subsequent processing. Two of the requirements for this task were to determine the minimum number of submerged, centrifugal pumps required to blend the salt mixtures in a full-scale tank in half a day or less, and to recommend reasonable blending times to achieve nearly homogeneous salt mixtures. A full-scale, low-flow pump with a total discharge flow rate of 500 to 800 gpm was recommended with two opposing 2.27-inch diameter nozzles. To make this recommendation, both experimental and CFD modeling were performed. Lab researchers found that, although CFD provided good estimates of an average blending time, experimental blending times varied significantly from the average.

  16. LES Simulations of Roll Clouds Observed During Mixed- Phase Arctic Cloud Experiment

    SciTech Connect (OSTI)

    Greenberg, S.D.; Harrington, J.Y.; Prenni, A.; DeMott, P.

    2005-03-18T23:59:59.000Z

    Roll clouds, and associated roll convection, are fairly common features of the atmospheric boundary layer. While these organized cumuliform clouds are found over many regions of the planet, they are quite ubiquitous near the edge of the polar ice sheets. In particular, during periods of off-ice flow, when cold polar air flows from the ice pack over the relatively warm ocean water, strong boundary layer convection develops along with frequent rolls. According to Bruemmer and Pohlman (2000), most of the total cloud cover in the Arctic is due to roll clouds. In an effort to examine the influences of mixed-phase microphysics on the boundary layer evolution of roll clouds during off-ice flow, Olsson and Harrington (2000) used a 2D mesoscale model coupled to a bulk microphysical scheme (see Section 2). Their results showed that mixed-phase clouds produced more shallow boundary layers with weaker turbulence than liquid-phase cases. Furthermore, their results showed that because of th e reduced turbulent drag on the atmosphere in the mixed-phase case, regions of mesoscale divergence in the marginal ice-zone were significantly affected. A follow-up 2D study (Harrington and Olsson 2001) showed that the reduced turbulent intensity in mixed-phase cases was due to precipitation. Ice precipitation caused downdraft stabilization which fed back and caused a reduction in the surface heat fluxes. In this work, we extend the work of Olsson and Harrington (2000) and Harrington and Olsson (2001) by examining the impacts of ice microphysics on roll convection. We will present results that illustrate how microphysics alters roll cloud structure and dynamics.

  17. Synthesis and Characterization of Metal Complexes to be Employed in the Catalytic Depolymerization of Lignin Model Compounds

    SciTech Connect (OSTI)

    Chmely, S. C.; Kim, S.; Beckham, G. T.

    2012-01-01T23:59:59.000Z

    Lignin is an earth-abundant biopolymer that is grossly underutilized as a value stream in current biomass conversion technologies because there exist no economic and technically feasible routes for lignin depolymerization and upgrading to fuels and chemicals. The development of new mild and selective catalytic routes to depolymerize this recalcitrant biopolymer is required to more effectively utilize lignin. To that end, our group aims to synthesize and characterize a collection of organometallic catalysts to promote atom-economical catalytic lignin deconstruction. These catalysts have been screened against dimeric lignin model compounds in order to gain mechanistic insights into their modes of action. In addition, experimental efforts have been coupled with quantum mechanical calculations to elucidate solution behavior of the catalysts as well as the mechanisms of lignin depolymerization. Detailed synthetic procedures, as well as spectroscopic and crystallographic characterization and DFT calculations will be presented.

  18. Managing Complexity

    SciTech Connect (OSTI)

    Chassin, David P.; Posse, Christian; Malard, Joel M.

    2004-08-01T23:59:59.000Z

    Physical analogs have shown considerable promise for understanding the behavior of complex adaptive systems, including macroeconomics, biological systems, social networks, and electric power markets. Many of today’s most challenging technical and policy questions can be reduced to a distributed economic control problem. Indeed, economically-based control of large-scale systems is founded on the conjecture that the price-based regulation (e.g., auctions, markets) results in an optimal allocation of resources and emergent optimal system control. This paper explores the state of the art in the use physical analogs for understanding the behavior of some econophysical systems and to deriving stable and robust control strategies for them. In particular we review and discussion applications of some analytic methods based on the thermodynamic metaphor according to which the interplay between system entropy and conservation laws gives rise to intuitive and governing global properties of complex systems that cannot be otherwise understood.

  19. Export of nutrients from the Arctic Ocean Sinhu Torres-Valds,1

    E-Print Network [OSTI]

    Naveira Garabato, Alberto

    Export of nutrients from the Arctic Ocean Sinhué Torres-Valdés,1 Takamasa Tsubouchi,2 Sheldon Bacon Strait, the Barents Sea Opening (BSO), and Bering Strait. We found that the major exports of all three budgets show that statistically robust net silicate and phosphate exports exist, while the net nitrate

  20. Atlantic meridional overturning and climate response to Arctic Ocean W. R. Peltier,1

    E-Print Network [OSTI]

    Peltier, W. Richard

    Atlantic meridional overturning and climate response to Arctic Ocean freshening W. R. Peltier,1 G to the response to North Atlantic freshening. Citation: Peltier, W. R., G. Vettoretti, and M. Stastna (2006 of the Atlantic by Heinrich Event 1 [Peltier, 2005]. Simi- larly, the onset of the Younger Dryas (Y-D) cold

  1. Tracer studies of pathways and rates of meltwater transport through Arctic summer sea ice

    E-Print Network [OSTI]

    Eicken, Hajo

    Tracer studies of pathways and rates of meltwater transport through Arctic summer sea ice H. Eicken) program's field site in the northern Chukchi Sea, snow and ice meltwater flow was found to have a strong impact on the heat and mass balance of sea ice during the summer of 1998. Pathways and rates of meltwater

  2. Peeking through a frosty window: molecular insights into the ecology of Arctic soil fungi

    E-Print Network [OSTI]

    Taylor, Lee

    TIMLING*, D. Lee TAYLOR Institute of Arctic Biology, University of Alaska, Fairbanks, AK 99775, USA a r Mycological Society. All rights reserved. doi:10.1016/j.funeco.2012.01.009 f u n g a l e c o l o g y 5 ( 2 0 1

  3. 255FEBRUARY 2002AMERICAN METEOROLOGICAL SOCIETY | he Surface Heat Budget of the Arctic Ocean

    E-Print Network [OSTI]

    Shupe, Matthew

    that determine the surface energy budget and the sea­ice mass balance in the Arctic (Moritz et al. 1993; Perovich of the vertical and horizontal energy exchanges within the ocean­ice­atmosphere system. The SHEBA pro- gram for Atmospheric Research, Boulder, Colorado; TURENNE--Canadian Coast Guard, Quebec City, Quebec, Canada; SERREZE

  4. Influence of transport and ocean ice extent on biogenic aerosol sulfur in the Arctic atmosphere

    E-Print Network [OSTI]

    Influence of transport and ocean ice extent on biogenic aerosol sulfur in the Arctic atmosphere S, such as methanesulfonic acid (MSA). This study examines relationships between changes in total sea ice extent north of 70. These results suggest that a decrease in seasonal ice cover influencing other mechanisms of DMS production could

  5. Underwater radiated noise levels of a research icebreaker in the central Arctic Ocean

    E-Print Network [OSTI]

    New Hampshire, University of

    , and search and rescue. The thinning Arctic ice pack and advances in ship design are allowing for longer of ice-breaking operations. Propulsion modes included transit in variable ice cover, breaking heavy iceHz when breaking ice. The highest noise levels resulted while the ship was engaged in backing

  6. A possible mechanism for combined chlorine and bromine catalyzed destruction of tropospheric ozone in the arctic

    SciTech Connect (OSTI)

    Le Bras, G. [Laboratoire de Combustion et Systemes Reactifs, Orleans (France)] [Laboratoire de Combustion et Systemes Reactifs, Orleans (France); Platt, U. [Univ. of Heidelberg (Germany)] [Univ. of Heidelberg (Germany)

    1995-03-01T23:59:59.000Z

    The authors make use of measured BrO radical densities, and ClO radical densities inferred from hydrocarbon measurements, made in the arctic troposphere, to calculate ozone depletion rates which would be expected in the spring. These rates compare favorably with field measurements.

  7. SHAPE-CONSTRAINED SEGMENTATION APPROACH FOR ARCTIC MULTIYEAR SEA ICE FLOE ANALYSIS

    E-Print Network [OSTI]

    Boyer, Edmond

    SHAPE-CONSTRAINED SEGMENTATION APPROACH FOR ARCTIC MULTIYEAR SEA ICE FLOE ANALYSIS Yuliya Tarabalka Research Association, MD, USA. e-mail: yuliya.tarabalka@inria.fr ABSTRACT The melting of sea ice, it is important to investigate how rapidly sea ice floes melt. For this purpose, a new TempoSeg method

  8. TOPOGRAPHY OF TITAN'S ARCTIC LAKE DISTRICT: IMPLICATIONS FOR SUBSURFACE LIQUID ALKANE FLOW. K. L. Mitchell1

    E-Print Network [OSTI]

    TOPOGRAPHY OF TITAN'S ARCTIC LAKE DISTRICT: IMPLICATIONS FOR SUBSURFACE LIQUID ALKANE FLOW. K. L Monopulse Amplitude Comparison method [3]. This technique estimates surface heights by comparing of good radar return where topography varies within the measurement width, and insufficient in areas

  9. Five Stages of the Alaskan Arctic Cold Season with Ecosystem Implications

    E-Print Network [OSTI]

    Sturm, Matthew

    1 Five Stages of the Alaskan Arctic Cold Season with Ecosystem Implications Peter Q. Olsson1 ecosystem processes. During the two autumnal stages (Early Snow and Early Cold) soils remain warm, unfrozen with the least amount of biological activity and have the least impact on the ecosystem. However, Early Snow

  10. Arctic Region Evaluation of the Hydro-Thermodynamic Soil Vegetation Scheme (HTSVS)

    E-Print Network [OSTI]

    Moelders, Nicole

    Arctic Region Evaluation of the Hydro-Thermodynamic Soil Vegetation Scheme (HTSVS) Pamela Spier, University of Alaska, Fairbanks, AK Abstract This paper presents an evaluation of the Hydro. Introduction and Motivation The Hydro-Thermodynamic Soil Vegetation Scheme (HTSVS, Kramm et al. 1996, Mölders

  11. Validation of Water Vapour Profiles from GPS Radio Occultations in the Arctic

    E-Print Network [OSTI]

    gas in the Earth's atmosphere, in- ducing about two third of the natural greenhouse effect anthropogenic effects from natural variability and to understand the radiative feed back from increasing water Center for Medium Range Weather Forecast (ECMWF) will be investigated for Arctic conditions. RO humidity

  12. Does Growth Rate Determine the Rate of Metabolism in Shorebird Chicks Living in the Arctic?

    E-Print Network [OSTI]

    Williams, Jos. B.

    primarily of greater metabolic inten- sities of heat-generating tissues. The maximum temperature gradient500 Does Growth Rate Determine the Rate of Metabolism in Shorebird Chicks Living in the Arctic/22/2007; Electronically Published 7/13/2007 ABSTRACT We measured resting and peak metabolic rates (RMR and PMR

  13. Latitudinal gradients in sea ice and primary production determine Arctic seabird colony

    E-Print Network [OSTI]

    Laidre, Kristin L.

    will indirectly alter energy transfer through the pelagic food web and ultimately impact apex predators. We-based observations of sea ice concentration from the Nimbus-7 scanning multichannel microwave radiometer (SMMR, 1979 recession of high Arctic seasonal ice cover created a temporally predictable primary production bloom

  14. Comparison of surface radiative flux data sets over the Arctic Ocean Jiping Liu,1,2

    E-Print Network [OSTI]

    . The reduced surface heat loss is partly offset by the reduction of solar heating due to much higher snow of these surface parameters was compared to the high-quality in situ measurements from the Surface Heat Budget; Intergovernmental Panel on Climate Change, 2001]. However, physical processes in the Arctic are not well understood

  15. Migratory connectivity in Arctic geese: spring stopovers are the weak links in meeting targets for breeding

    E-Print Network [OSTI]

    Kleyer, Michael

    makes geese particularly vul- nerable to the impact of climate change. There is an increasing mismatch trends in the Arctic target areas. Keywords Capital breeding Á Climate change Á Energetic costs 119313, Russia J. Stahl Landscape Ecology Group, University of Oldenburg, 26111 Oldenburg, Germany 123 J

  16. Topographic Controls on LAI in Arctic Tundra Luke Spadavecchia -54 -2008

    E-Print Network [OSTI]

    and surface energy balance, which can vary by an order of magnitude among Arctic tundra communities. We Spadavecchia - 55 - 2008 4.1 Declaration The following chapter was submitted to the Journal of Ecology and plant functional type of a tundra ecosystem'. Journal of Ecology 96(6): 1238-1251) we correct

  17. Response of the Greenland-Scotland overflow to changing deep water supply from the Arctic Mediterranean

    E-Print Network [OSTI]

    Response of the Greenland-Scotland overflow to changing deep water supply from the Arctic with a topographic barrier is used to study the response of the overflows across the Greenland-Scotland Ridge of the exchanges across the ridge is seen when the supply decreases. Transport variations in the East-Greenland

  18. Arctic sea ice and atmospheric circulation under the GeoMIP G1 scenario

    E-Print Network [OSTI]

    Robock, Alan

    Arctic sea ice and atmospheric circulation under the GeoMIP G1 scenario John C. Moore1 , Annette Rinke1,2 , Xiaoyong Yu1 , Duoying Ji1 , Xuefeng Cui1 , Yan Li3 , Kari Alterskjær4 , Jón Egill Centre, Danish Meteorological Institute, Copenhagen, Denmark Abstract We analyze simulated sea ice

  19. Black carbon in Arctic snow and its effect on surface albedo

    E-Print Network [OSTI]

    1 Black carbon in Arctic snow and its effect on surface albedo Stephen Warren, University wavelengths: ice is nearly transparent. Absorptive impurities: Black carbon (soot) Brown carbon (organics broadband albedo: 83% 71% (2) by addition of black carbon (BC) (20 ppb): 0.5% for r = 100 µm 1.6% for r

  20. Arctic methane sources: Isotopic evidence for atmospheric inputs R. E. Fisher,1

    E-Print Network [OSTI]

    Sheldon, Nathan D.

    Arctic methane sources: Isotopic evidence for atmospheric inputs R. E. Fisher,1 S. Sriskantharajah,1 D. Lowry,1 M. Lanoisellé,1 C. M. R. Fowler,1 R. H. James,2 O. Hermansen,3 C. Lund Myhre,3 A. Stohl,3 J. Greinert,4 P. B. R. NisbetJones,5 J. Mienert,6 and E. G. Nisbet1 Received 16 August 2011

  1. The great 2012 Arctic Ocean summer cyclone enhanced biological productivity on the shelves

    E-Print Network [OSTI]

    Zhang, Jinlun

    The great 2012 Arctic Ocean summer cyclone enhanced biological productivity on the shelves Jinlun influences the marine planktonic ecosystem by enhancing productivity on the shelves of the Chukchi, East days, the simulated biological effects on the shelves last 1 month or longer. At some locations

  2. This chapter describes observations of continuing change in the Arctic environmental system. It is or-

    E-Print Network [OSTI]

    Bhatt, Uma

    for the longest period and largest area of ice sheet melt since at least 1978, and the highest melt rate since in the Canadian Arctic, where the rate of mass loss from small glaciers and ice caps continued to increase system. It is or- ganized into five broad sections: atmosphere, ocean, sea ice cover, land, and Greenland

  3. Author's personal copy Latest Pleistocene and Holocene glaciation of Baffin Island, Arctic Canada: key

    E-Print Network [OSTI]

    Briner, Jason P.

    t Melting glaciers and ice caps on Baffin Island contribute roughly half of the sea-level rise from all ice future response of arctic glaciers and ice caps to climate change motivates the use of paleodata throughout the Holocene to its present margin (Barnes Ice Cap) except for two periods of rapid retreat

  4. Short-lived pollutants in the Arctic: their climate impact and possible mitigation strategies

    SciTech Connect (OSTI)

    Menon, Surabi; Quinn, P.K.; Bates, T.S.; Baum, E.; Doubleday, N.; Fiore, A.M.; Flanner, M.; Fridlind, A.; Garrett, T.J.; Koch, D.; Menon, S.; Shindell, D.; Stohl, A.; Warren, S.G.

    2007-09-24T23:59:59.000Z

    Several short-lived pollutants known to impact Arctic climate may be contributing to the accelerated rates of warming observed in this region relative to the global annually averaged temperature increase. Here, we present a summary of the short-lived pollutants that impact Arctic climate including methane, tropospheric ozone, and tropospheric aerosols. For each pollutant, we provide a description of the major sources and the mechanism of forcing. We also provide the first seasonally averaged forcing and corresponding temperature response estimates focused specifically on the Arctic. The calculations indicate that the forcings due to black carbon, methane, and tropospheric ozone lead to a positive surface temperature response indicating the need to reduce emissions of these species within and outside the Arctic. Additional aerosol species may also lead to surface warming if the aerosol is coincident with thin, low lying clouds. We suggest strategies for reducing the warming based on current knowledge and discuss directions for future research to address the large remaining uncertainties.

  5. Vegetation responses in Alaskan arctic tundra after 8 years of a summer warming and winter snow

    E-Print Network [OSTI]

    Ickert-Bond, Steffi

    by insulating vegetation from winter wind and temperature extremes, modifying winter soil temperaturesVegetation responses in Alaskan arctic tundra after 8 years of a summer warming and winter snow ) open-topped fiberglass chambers (OTCs) to study the effects of changes in winter snow cover and summer

  6. Quaternary Science Reviews 21 (2002) 9971021 Responses of an arctic landscape to Lateglacial and early Holocene

    E-Print Network [OSTI]

    Ltd. All rights reserved. 1. Introduction The Arctic is important to global climate because its Earth Observatory, Palisades, NY 10964, USA c Reanier and Associates, 1807 Thirty Second Avenue, Seattle to the YD are rare, suggesting that rates of paludification slowed. Immediately after 10,000 14 C yr BP

  7. Radiative and microphysical properties of Arctic stratus clouds from multiangle downwelling infrared radiances

    E-Print Network [OSTI]

    Shupe, Matthew

    climate is strongly influenced by an extensive and persistent pattern of cloud cover [Francis, 1997 properties can have significant effects on long- wave radiation, which dominates the radiation energy budgetRadiative and microphysical properties of Arctic stratus clouds from multiangle downwelling

  8. How does the atmospheric variability drive the aerosol residence time in the Arctic region?

    E-Print Network [OSTI]

    Paris-Sud XI, Université de

    for enhanced cloud evaporation and hence a decrease in the fraction of solar radiation reflected by the cloud cover. This strong climatic retroaction is referred to as the `semi-direct effect' of BC aerosols. BC of the atmospheric aerosol concentration is paramount to assess its radiative effects in the Arctic, a region

  9. Interannual variations of Arctic cloud types in relation to Ryan Eastman

    E-Print Network [OSTI]

    Hochberg, Michael

    increasing cloud cover, which may promote ice loss by the longwave effect. The trends are positive in all in sea ice extent and thickness may be affected by cloud radiative effect (CRE), and seaice changes may in turn impart changes to cloud cover. Visual cloud reports from land and ocean regions of the Arctic

  10. Relationships between Arctic Sea Ice and Clouds during Autumn AXEL J. SCHWEIGER AND RON W. LINDSAY

    E-Print Network [OSTI]

    Francis, Jennifer

    , as the direct radiative effects of cloud cover changes are compensated for by changes in the temperature The connection between sea ice variability and cloud cover over the Arctic seas during autumn is investigated that cloud cover variability near the sea ice margins is strongly linked to sea ice variability. Sea ice

  11. Expected magnitude of the aerosol shortwave indirect effect in springtime Arctic liquid water clouds

    E-Print Network [OSTI]

    reflection of photons between the snow or sea ice surface and cloud base, the shortwave first indirect effect of high quality longwave spectral radiation measurements in the Arctic from which the indirect effect can clouds both absorb and scatter radiation. We therefore do not yet have a comparable spectral capability

  12. Arctic Oscillation response to the 1991 Mount Pinatubo eruption: Effects of volcanic aerosols and ozone depletion

    E-Print Network [OSTI]

    Robock, Alan

    of perturbation experiments, the full radiative effects of the observed Pinatubo aerosol cloud were included eruption, which produced the largest global volcanic aerosol cloud in the twentieth century. A seriesArctic Oscillation response to the 1991 Mount Pinatubo eruption: Effects of volcanic aerosols

  13. On the two principal curvatures as possible entropic barriers in a mesoscopic nonequilibrium thermodynamics model of complex matter agglomeration

    E-Print Network [OSTI]

    A. Gadomski; J. M. Rubi

    2003-02-06T23:59:59.000Z

    Matter agglomeration mesoscopic phenomena of irreversible type are well described by nonequilibrium thermodynamics formalism. The description assumes that the thermodynamic (internal) state variables are in local equilibrium, and uses the well known flux-force relations, with the Onsager coefficients involved, ending eventually up at a local conservation law of Fokker-Planck type. One of central problems arising when applying it to the matter agglomeration phenomena, quite generally termed nucleation-and-growth process, appears to be some physically accepted identification of entropic barriers, or factors impeding growth. In this paper, we wish to propose certain geometric-kinetic obstacles as serious candidates for the so-called entropic barriers. Within the framework of the thermodynamic formalism offered they are always associated with a suitable choice of a physical potential governing the system. It turns out that a certain choice of the potential of Coulomb (or, gravitational) type leads to emphasizing the role of the Gaussian curvature while another choice in a form of the logaritmic physical potential results unavoidably in a pronounced role of the mean curvature. The whole reasoning has been tested succesfully on a statistical-mechanical polycris- talline evolution model introduced some years ago for physical-metalurgical purposes, and modified for a use in biophysical soft-matter agglomerations.

  14. Next-Generation Ecosystem Experiments NGEE Arctic Quarterly Report

    E-Print Network [OSTI]

    land model for inclusion in Earth system models. #12;3 Details at a Glance Activities during the April

  15. Conceptual Models for Migration of Key Groundwater Contaminants Through the Vadose Zone and Into the Upper Unconfined Aquifer Below the B-Complex

    SciTech Connect (OSTI)

    Serne, R. Jeffrey; Bjornstad, Bruce N.; Keller, Jason M.; Thorne, Paul D.; Lanigan, David C.; Christensen, J. N.; Thomas, Gregory S.

    2010-07-01T23:59:59.000Z

    The B-Complex contains 3 major crib and trench disposal sites and 3 SST farms that have released nearly 346 mega-liters of waste liquids containing the following high groundwater risk drivers: ~14,000 kg of CN, 29,000 kg of Cr, 12,000 kg of U and 145 Ci of Tc-99. After a thorough review of available vadose zone sediment and pore water, groundwater plume, field gamma logging, field electrical resistivity studies, we developed conceptual models for which facilities have been the significant sources of the contaminants in the groundwater and estimated the masses of these contaminants remaining in the vadose zone and currently present in the groundwater in comparison to the totals released. This allowed us to make mass balance calculations on how consistent our knowledge is on the current deep vadose zone and groundwater distribution of contaminants. Strengths and weaknesses of the conceptual models are discussed as well as implications on future groundwater and deep vadose zone remediation alternatives. Our hypothesized conceptual models attribute the source of all of the cyanide and most of the Tc-99 currently in the groundwater to the BY cribs. The source of the uranium is the BX-102 tank overfill event and the source of most of the chromium is the B-7-A&B and B-8 cribs. Our mass balance estimates suggest that there are much larger masses of U, CN, and Tc remaining in the deep vadose zone within ~20 ft of the water table than is currently in the groundwater plumes below the B-Complex. This hypothesis needs to be carefully considered before future remediation efforts are chosen. The masses of these groundwater risk drivers in the the groundwater plumes have been increasing over the last decade and the groundwater plumes are migrating to the northwest towards the Gable Gap. The groundwater flow rate appears to flucuate in response to seasonal changes in hydraulic gradient. The flux of contaminants out of the deep vadose zone from the three proposed sources also appears to be transient such that the evolution of the contaminant plumes is transient.

  16. Theories of phosphorescence in organo-transition metal complexes - from relativistic effects to simple models and design principles for organic light-emitting diodes

    E-Print Network [OSTI]

    Powell, B J

    2015-01-01T23:59:59.000Z

    We review theories of phosphorescence in cyclometalated complexes. We focus primarily on pseudooctahedrally coordinated $t_{2g}^6$ metals (e.g., [Os(II)(bpy)$_3$]$^{2+}$, Ir(III)(ppy)$_3$ and Ir(III)(ptz)$_3$) as, for reasons that are explored in detail, these show particularly strong phosphorescence. We discuss both first principles approaches and semi-empirical models, e.g., ligand field theory. We show that together these provide a clear understanding of the photophysics and in particular the lowest energy triplet excitation, T$_1$. In order to build a good model relativistic effects need to be included. The role of spin-orbit coupling is well-known, but scalar relativistic effects are also large - and are therefore also introduced and discussed. No expertise in special relativity or relativistic quantum mechanics is assumed and a pedagogical introduction to these subjects is given. It is shown that, once both scalar relativistic effects and spin-orbit coupling are included, time dependent density function...

  17. Sources of spread in simulations of Arctic sea ice loss over the twenty-first century: A letter

    E-Print Network [OSTI]

    Boé, Julien; Hall, Alex; Qu, Xin

    2010-01-01T23:59:59.000Z

    the ultimate fate of the ice pack. 1 Introduction Over theof the entire year’s ice pack (Fig. 3b). The relationshipultimate fate of the Arctic ice pack. In Boé et al. (2009b)

  18. Climatic responses in spring migration of boreal and arctic birds in relation to wintering area and taxonomy

    E-Print Network [OSTI]

    Laaksonen, Toni

    and taxonomy Kalle Rainio, Toni Laaksonen, Markus Ahola, Anssi V. Va¨ha¨talo and Esa Lehikoinen Rainio, K of boreal and arctic birds in relation to wintering area and taxonomy. Á J. Avian Biol. 37: 507Á515. Large

  19. Breaking the Ice: Navigation in the Arctic Grace Xingxin Gao, Liang Heng, Todd Walter, and Per Enge

    E-Print Network [OSTI]

    Gao, Grace Xingxin

    Breaking the Ice: Navigation in the Arctic Grace Xingxin Gao, Liang Heng, Todd Walter, and Per Enge (ION) Early Achievement Award. Liang Heng is a Ph.D. candidate under the guidance of Professor Per Enge

  20. Phylogenetic relationships, host affinity, and geographic structure of boreal and arctic endophytes from three major plant lineages

    E-Print Network [OSTI]

    Arnold, A. Elizabeth

    Phylogenetic relationships, host affinity, and geographic structure of boreal and arctic endophytes Although associated with all plants, fungal endophytes (microfungi that live within healthy plant tissues, or phylogenetic relationships. We surveyed endophytic Ascomycota from healthy photosyn- thetic tissues of three

  1. A Comparison of Atmospheric Reanalysis Products for the Arctic Ocean and Implications for Uncertainties in Air–Sea Fluxes

    E-Print Network [OSTI]

    Chaudhuri, Ayan H.

    The uncertainties related to atmospheric fields in the Arctic Ocean from commonly used and recently available reanalysis products are investigated. Fields from the 1) ECMWF Interim Re-Analysis (ERA-Interim), 2) Common ...

  2. The development of a signal processing network for a real-time Arctic sea ice classification system

    E-Print Network [OSTI]

    Nordhaus, William D

    1973-01-01T23:59:59.000Z

    THE DEVELOPMENT OF A SIGNAL PROCESSING NETWORK FOR A REAL-TIME ARCTIC SEA ICE CLASSIFICATION SYSTEM A Thesis by WILLIAM DOUGLAS NORDHAUS Submitted to the Graduate College of Texas A)M University in partial fulfillment of the requirement... for the degree of MASTER OF SCIENCE August 1973 Major Subject: Electrical Engineering THE DEVELOPMENT OF A SIGNAL PROCESSING NETWORK FOR A REAL-TIME ARCTIC SEA ICE CLASSIFICATION SYSTEM A Thesis by William Douglas Nordhaus Approved as to style...

  3. Towards Quantifying Complexity with Quantum Mechanics

    E-Print Network [OSTI]

    Ryan Tan; Daniel R. Terno; Jayne Thompson; Vlatko Vedral; Mile Gu

    2014-09-23T23:59:59.000Z

    While we have intuitive notions of structure and complexity, the formalization of this intuition is non-trivial. The statistical complexity is a popular candidate. It is based on the idea that the complexity of a process can be quantified by the complexity of its simplest mathematical model - the model that requires the least past information for optimal future prediction. Here we review how such models, known as $\\epsilon$-machines can be further simplified through quantum logic, and explore the resulting consequences for understanding complexity. In particular, we propose a new measure of complexity based on quantum $\\epsilon$-machines. We apply this to a simple system undergoing constant thermalization. The resulting quantum measure of complexity aligns more closely with our intuition of how complexity should behave.

  4. Simulating the Daylight Performance of Complex Fenestration Systems Using

    E-Print Network [OSTI]

    LBNL-4414E Simulating the Daylight Performance of Complex Fenestration Systems Using Bidirectional, January 21, 2011. 1 Simulating the Daylight Performance of Complex Fenestration Systems Using (BSDFs) to model the daylighting performance of complex fenestration systems (CFS), enabling greater

  5. Complexity and Productivity Differentiation Models of Metallogenic Indicator Elements in Rocks and Supergene Media Around Daijiazhuang Pb-Zn Deposit in Dangchang County, Gansu Province

    SciTech Connect (OSTI)

    He, Jin-zhong, E-mail: viewsino@163.com; Yao, Shu-zhen [China University of Geosciences, State Key Laboratory of Geological Processes and Mineral Resources (China)] [China University of Geosciences, State Key Laboratory of Geological Processes and Mineral Resources (China); Zhang, Zhong-ping; You, Guan-jin [Geological Surveying Institute of Gansu Province (China)] [Geological Surveying Institute of Gansu Province (China)

    2013-03-15T23:59:59.000Z

    With the help of complexity indices, we quantitatively studied multifractals, frequency distributions, and linear and nonlinear characteristics of geochemical data for exploration of the Daijiazhuang Pb-Zn deposit. Furthermore, we derived productivity differentiation models of elements from thermodynamics and self-organized criticality of metallogenic systems. With respect to frequency distributions and multifractals, only Zn in rocks and most elements except Sb in secondary media, which had been derived mainly from weathering and alluviation, exhibit nonlinear distributions. The relations of productivity to concentrations of metallogenic elements and paragenic elements in rocks and those of elements strongly leached in secondary media can be seen as linear addition of exponential functions with a characteristic weak chaos. The relations of associated elements such as Mo, Sb, and Hg in rocks and other elements in secondary media can be expressed as an exponential function, and the relations of one-phase self-organized geological or metallogenic processes can be represented by a power function, each representing secondary chaos or strong chaos. For secondary media, exploration data of most elements should be processed using nonlinear mathematical methods or should be transformed to linear distributions before processing using linear mathematical methods.

  6. arXiv:0806.0387v4[math.OC]24Jun2009 Euler-Lagrange models with complex currents of

    E-Print Network [OSTI]

    Paris-Sud XI, Université de

    to derive the Euler-Lagrange equations with complex stator and rotor currents. Such complexification process and of a magnetic one. This magnetic Lagrangian is expressed in terms of rotor angle, complex stator and rotor-called sensorless case when the measured output is the stator current and the load torque is constant but unknown

  7. Spatial and seasonal variations of hexachlorocyclohexanes (HCHs) and hexachlorobenzene (HCB) in the arctic atmosphere

    SciTech Connect (OSTI)

    Su, Yushan; Hung, Hayley; Blanchard, Pierrette; Patton, Gregory W.; Kallenborn, Roland; Konoplev, Alexei V.; Fellin, Phil; Li, Henrik; Geen, Charles; Stern, Gary; Rosenburg, Bruno; Barrie, Leonard A.

    2006-11-01T23:59:59.000Z

    Weekly high volume air samples were concurrently collected between 2000 and 2003 at six arctic sites, namely Alert, Little Fox Lake, Kinngait in Canada; Point Barrow in Alaska, USA; Zeppelin in Norway; and Valkarkai in Russia. Hexachlorocyclohexanes (HCHs) and hexachlorobenzene (HCB) were quantified in all samples. Data comparison showed that ?-HCH and HCB were relatively homogeneously distributed in the circumpolar atmosphere and fairly uniform throughout the seasons. However, significantly high atmospheric ?-HCH and HCB concentrations and strong seasonality of ?-HCH and ?-HCH were found at the low arctic site of Little Fox Lake. Stronger temperature dependence of ?-HCH and ?-HCH at this location suggests that secondary emissions (or re-evaporation from surface environmental media) were more important at this site than others. Tendency of the secondary emissions also appeared increased compared to a decade ago in this region. It is thus hypothesized that higher precipitation rate at this topographically elevated station facilitated the transfer of ?-HCH from the atmosphere to surface media when technical HCH was still being used worldwide. On the other hand, relatively higher temperature at this southerly station enhanced re-evaporation to the atmosphere after the global ban of technical HCH. In contrast, larger spatial and seasonal discrepancies were apparent for ''current-use'' ?-HCH than ?-HCH and HCB in the arctic atmosphere. It likely reflected different influences of primary contaminant sources on various arctic locations. Calculations of fugacity ratio suggest slight net deposition potential of HCB from air to seawater in the circumpolar environment, whereas air/seawater exchange direction of ?-HCH varied from location to location in this region.

  8. Estimating Migration Resistance: a Case Study of Greenlandic Arctic Terns

    E-Print Network [OSTI]

    Hensz, Christopher

    2013-01-15T23:59:59.000Z

    differences in environments along both paths Data ? Remote sensing: ? CCMP ocean winds ? AVHRR temperature ? AVHRR sea ice ? NPP layer 4 product ? Models: ? Linear exploration ? Circular-linear regression ? Non-linear regression m g C /m 2... d ay °C m /s Models ? Implemented in R ? Models: ? Linear exploration Southern Migration, 9 birds, n=929 Northern Migration, 9 birds, n=629 Future Directions 1: Finish non-linear model 2: Generalize procedure and include...

  9. Near UV atmospheric absorption measurements of column abundances during Airborne Arctic Stratospheric Expedition, January-February 1989: 2. OClO observations

    SciTech Connect (OSTI)

    Schiller, C.; Wahner, A.; Platt, U.; Dorn, H.P.; Callies, J.; Ehhalt, D.H. (Kernforschungsanlage Juelich (West Germany))

    1990-03-01T23:59:59.000Z

    Column abundances of OClO were measured during the Airborne Arctic Stratospheric Expedition from January 6 to February 9, 1989 by near UV absorption spectroscopy. OClO was detected during AASE inside the vortex and at the edge of the vortex with column abundances of 3-10 {times} 10{sup 12} cm{sup {minus}2} under twilight conditions and up to 1 {times} 10{sup 14} cm{sup {minus}2} during the night. For comparison, in the Antarctic winter nighttime column abundances of OClO ranged from 1-2.5 {times} 10{sup 14} cm{sup {minus}2}, while those at mid-latitudes were below the detection limit, i.e. by at least a factor of 10 lower (Solomon et al., 1988). The measurements are broadly consistent with observed BrO column abundances and chemical model calculations.

  10. arctic coastline eroding: Topics by E-print Network

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

    of spatial long-range correlations in the lithology of coastal landscapes on the fractal behavior of the corresponding coastlines. In the model, the resistance of a coast...

  11. arctic sea ice: Topics by E-print Network

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

    AD of transient model simulations and a new type of sen- sitivity experiments with artificial sea ice growth Born, Andreas 388 Sedimentation and particle dynamics in the...

  12. arctic ice dynamics: Topics by E-print Network

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

    W. F. Vincent (2008), Seasonal dynamics of bacterial Vincent, Warwick F. 168 Dynamics of artificial spin ice: a continuous honeycomb network MIT - DSpace Summary: We model the...

  13. Bayesian nonparametric learning of complex dynamical phenomena

    E-Print Network [OSTI]

    Fox, Emily Beth

    2009-01-01T23:59:59.000Z

    The complexity of many dynamical phenomena precludes the use of linear models for which exact analytic techniques are available. However, inference on standard nonlinear models quickly becomes intractable. In some cases, ...

  14. The impact of an intense summer cyclone on 2012 Arctic sea ice retreat Jinlun Zhang, Ron Lindsay, Axel Schweiger, and Michael Steele

    E-Print Network [OSTI]

    Zhang, Jinlun

    Arctic ice volume had already declined ~40% from the 2007­2011 mean. The thin sea ice pack of the low-pressure system was well within the sea ice pack, with a minimum central pressure of 974.5 hThe impact of an intense summer cyclone on 2012 Arctic sea ice retreat Jinlun Zhang, Ron Lindsay

  15. Sea ice loss and the changing atmospheric CO2 uptake capacity of the Arctic Ocean: Insights1 from the southeastern Canada Basin2

    E-Print Network [OSTI]

    Paris-Sud XI, Université de

    Sea ice loss and the changing atmospheric CO2 uptake capacity of the Arctic Ocean: Insights1 from (Arctic Ocean) to act as an atmospheric CO2 sink under the summertime ice-free conditions12 expected in the near future. Beneath a heavily decayed ice cover, we found surprisingly high13 pCO2sw (~290-320 atm

  16. Population Size Does Not Predict Artifact Complexity: Analysis of Data from Tasmania, Arctic Hunter-Gatherers, and Oceania Fishing Groups

    E-Print Network [OSTI]

    Read, Dwight

    2012-01-01T23:59:59.000Z

    Australia. Canberra: Department of Prehistory, Australiain eastern Australia. Canberra: Australian National

  17. alkaline earth complexes: Topics by E-print Network

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

    56 Historical and idealized climate model experiments: an intercomparison of Earth system models of intermediate complexity MIT - DSpace Summary: Both historical and idealized...

  18. alkaline earth metal complexes: Topics by E-print Network

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

    87 Historical and idealized climate model experiments: an intercomparison of Earth system models of intermediate complexity MIT - DSpace Summary: Both historical and idealized...

  19. Complexity, Ecology, Finance

    E-Print Network [OSTI]

    2011-01-01T23:59:59.000Z

    Systemic risk in consumer finance Uncertain about risk HowComplexity, Ecology, Finance The Pre-History of ResilienceRisk Complexity, Ecology, Finance Andrew Haldane, Senior

  20. Microphysical Properties of Single and Mixed-Phase Arctic Clouds Derived from AERI Observations

    SciTech Connect (OSTI)

    Turner, David D.

    2003-06-01T23:59:59.000Z

    A novel new approach to retrieve cloud microphysical properties from mixed-phase clouds is presented. This algorithm retrieves cloud optical depth, ice fraction, and the effective size of the water and ice particles from ground-based, high-resolution infrared radiance observations. The theoretical basis is that the absorption coefficient of ice is stronger than that of liquid water from 10-13 mm, whereas liquid water is more absorbing than ice from 16-25 um. However, due to strong absorption in the rotational water vapor absorption band, the 16-25 um spectral region becomes opaque for significant water vapor burdens (i.e., for precipitable water vapor amounts over approximately 1 cm). The Arctic is characterized by its dry and cold atmosphere, as well as a preponderance of mixed-phase clouds, and thus this approach is applicable to Arctic clouds. Since this approach uses infrared observations, cloud properties are retrieved at night and during the long polar wintertime period. The analysis of the cloud properties retrieved during a 7 month period during the Surface Heat Budget of the Arctic (SHEBA) experiment demonstrates many interesting features. These results show a dependence of the optical depth on cloud phase, differences in the mode radius of the water droplets in liquid-only and mid-phase clouds, a lack of temperature dependence in the ice fraction for temperatures above 240 K, seasonal trends in the optical depth with the clouds being thinner in winter and becoming more optically thick in the late spring, and a seasonal trend in the effective size of the water droplets in liquid-only and mixed-phase clouds that is most likely related to aerosol concentration.

  1. Source Characterization and Temporal Variation of Methane Seepage from Thermokarst Lakes on the Alaska North Slope in Response to Arctic Climate Change

    SciTech Connect (OSTI)

    None

    2012-09-30T23:59:59.000Z

    The goals of this research were to characterize the source, magnitude and temporal variability of methane seepage from thermokarst lakes (TKL) within the Alaska North Slope gas hydrate province, assess the vulnerability of these areas to ongoing and future arctic climate change and determine if gas hydrate dissociation resulting from permafrost melting is contributing to the current lake emissions. Analyses were focused on four main lake locations referred to in this report: Lake Qalluuraq (referred to as Lake Q) and Lake Teshekpuk (both on Alaska?s North Slope) and Lake Killarney and Goldstream Bill Lake (both in Alaska?s interior). From analyses of gases coming from lakes in Alaska, we showed that ecological seeps are common in Alaska and they account for a larger source of atmospheric methane today than geologic subcap seeps. Emissions from the geologic source could increase with potential implications for climate warming feedbacks. Our analyses of TKL sites showing gas ebullition were complemented with geophysical surveys, providing important insight about the distribution of shallow gas in the sediments and the lake bottom manifestation of seepage (e.g., pockmarks). In Lake Q, Chirp data were limited in their capacity to image deeper sediments and did not capture the thaw bulb. The failure to capture the thaw bulb at Lake Q may in part be related to the fact that the present day lake is a remnant of an older, larger, and now-partially drained lake. These suggestions are consistent with our analyses of a dated core of sediment from the lake that shows that a wetland has been present at the site of Lake Q since approximately 12,000 thousand years ago. Chemical analyses of the core indicate that the availability of methane at the site has changed during the past and is correlated with past environmental changes (i.e. temperature and hydrology) in the Arctic. Discovery of methane seeps in Lake Teshekpuk in the northernmost part of the lake during 2009 reconnaissance surveys provided a strong impetus to visit this area in 2010. The seismic methods applied in Lake Teshekpuk were able to image pockmarks, widespread shallow gas in the sediments, and the relationship among different sediment packages on the lake?s bottom, but even boomer seismics did not detect permafrost beneath the northern part of the lake. By characterizing the biogeochemistry of shallow TKL with methane seeps we showed that the radical seasonal shifts in ice cover and temperature. These seasonal environmental differences result in distinct consumption and production processes of biologically-relevant compounds. The combined effects of temperature, ice-volume and other lithological factors linked to seepage from the lake are manifest in the distribution of sedimentary methane in Lake Q during icecovered and ice-free conditions. The biogeochemistry results illustrated very active methanotrophy in TKLs. Substantial effort was subsequently made to characterize the nature of methanotrophic communities in TKLs. We applied stable isotope probing approaches to genetically characterize the methanotrophs most active in utilizing methane in TKLs. Our study is the first to identify methane oxidizing organisms active in arctic TKLs, and revealing that type I methanotrophs and type II methanotrophs are abundant and active in assimilating methane in TKLs. These organisms play an important role in limiting the flux of methane from these sites. Our investigations indicate that as temperatures increase in the Arctic, oxidation rates and active methanotrophic populations will also shift. Whether these changes can offset predicted increases in methanogenesis is an important question underlying models of future methane flux and resultant climate change. Overall our findings indicate that TKLs and their ability to act as both source and sink of methane are exceedingly sensitive to environmental change.

  2. Effects of simulated natural variability on Arctic temperature projections

    E-Print Network [OSTI]

    Drange, Helge

    - sea ice-ocean model is used to examine the effects of natural variability on climate projections starting from different strengths and phases of the Atlantic Meridional Overturning Circulation and cryosphere give rise to a variety of climate feedbacks as such as ice- albedo and cloud feedbacks. The direct

  3. Next-Generation Ecosystem Experiments NGEE Arctic Quarterly Report

    E-Print Network [OSTI]

    Fairbanks performed hydrologic analyses using the physically-based model WaSiM-ETH that was forced by data, and processes such as evaporation. Measurement of chemical constituents that vary in concentration according transformations such as mineralization of organic matter to ammonia, nitrate, CO2, and methane. To determ

  4. Eighth International Congress of Arctic Social Sciences (ICASS VIII)

    E-Print Network [OSTI]

    Northern British Columbia, University of

    conglomerations, requires new models of food and energy security, and of access to employment, health care to sustainability. Appropriate governance regimes for renewable and non-renewable resources underpin sustainable website). You will need to provide a rough budget of your estimated travel expenses. We anticipate

  5. Summer in the Arctic | U.S. DOE Office of Science (SC)

    Office of Science (SC) Website

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative1 First Use of Energy for All Purposes (Fuel and Nonfuel), 2002; Level:Energy: Grid Integration Redefining What'sis Taking Over OurThe Iron4 Self-Scrubbing:,, ,Development1USummer in the Arctic News News Home

  6. Variable Infiltration Capacity model (VIC) is a macro-scale energy and water balance model with lake and wetland

    E-Print Network [OSTI]

    Cherkauer, Keith

    of surface storage in a low- gradient Arctic watershed, Water Resour. Res., 39(4), 1087, doi: 10.1029/2002WR (VIC) Cold Land Process Model Updates, Global and Planetary Change, 38, 151-159, 2003. Sathulur, K., L drainage, and expanding industrial and urban areas. The water table position usually acts as the dominant

  7. Hyper Space Complex Number

    E-Print Network [OSTI]

    Shanguang Tan

    2007-04-23T23:59:59.000Z

    A new kind of numbers called Hyper Space Complex Numbers and its algebras are defined and proved. It is with good properties as the classic Complex Numbers, such as expressed in coordinates, triangular and exponent forms and following the associative and commutative laws of addition and multiplication. So the classic Complex Number is developed from in complex plane with two dimensions to in complex space with N dimensions and the number system is enlarged also.

  8. ARM - Field Campaign - Supplement to Arctic Lower Troposphere Observed

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

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative1 First Use of Energy for All Purposes (Fuel and Nonfuel), 2002; Level: National5Sales for4,645U.S. DOE Office of ScienceandMesa- PolarizationgovCampaignsSummer Single Column Model IOP ARM Data Discovery

  9. PERFORMANCE OF A POLYMER SEALANT COATING IN AN ARCTIC MARINE ENVIRONMENT

    SciTech Connect (OSTI)

    MOSKOWITZ,P.; COWGILL,M.; GRIFFITH,A.; CHERNAENKO,L.; DIASHEV,A.; NAZARIAN,A.

    2001-02-25T23:59:59.000Z

    The feasibility of using a polymer-based coating, Polibrid 705, to seal concrete and steel surfaces from permanent radioactive contamination in an Arctic marine environment has been successfully demonstrated using a combination of field and laboratory testing. A mobile, self-sufficient spraying device was developed to specifications provided by the Russian Northern Navy and deployed at the RTP Atomflot site, Murmansk, Russia. Demonstration coatings were applied to concrete surfaces exposed to conditions ranging from indoor pedestrian usage to heavy vehicle passage and container handling in a loading dock. A large steel container was also coated with the polymer, filled with solid radwaste, sealed, and left out of doors, exposed to the full annual Arctic weather cycle. The 12 months of field testing gave rise to little degradation of the sealant coating, except for a few chips and gouge marks on the loading bay surface that were readily repaired. Contamination resulting from radwaste handling was easily removed and the surface was not degraded by contact with the decontamination agents. The field tests were accompanied by a series of laboratory qualification tests carried out at a research laboratory in St. Petersburg. The laboratory tests examined a variety of properties, including bond strength between the coating and the substrate, thermal cycling resistance, wear resistance, flammability, and ease of decontamination. The Polibrid 705 coating met all the Russian Navy qualification requirements with the exception of flammability. In this last instance, it was decided to restrict application of the coating to land-based facilities.

  10. PERFORMANCE OF A POLYMER SEALANT COATING IN AN ARCTIC MARINE ENVIRONMENT.

    SciTech Connect (OSTI)

    MOSKOWITZ,P.; COWGILL,M.; GRIFFITH,A.; CHERNAENKO,L.; DIASHEV,A.; NAZARIAN,A.

    2001-02-25T23:59:59.000Z

    The feasibility of using a polymer-based coating, Polibrid 705, to seal concrete and steel surfaces from permanent radioactive contamination in an Arctic marine environment has been successfully demonstrated using a combination of field and laboratory testing. A mobile, self-sufficient spraying device was developed to specifications provided by the Russian Northern Navy and deployed at the RTP Atomflot site, Murmansk, Russia. Demonstration coatings were applied to concrete surfaces exposed to conditions ranging from indoor pedestrian usage to heavy vehicle passage and container handling in a loading dock. A large steel container was also coated with the polymer, filled with solid radwaste, sealed, and left out of doors, exposed to the full annual Arctic weather cycle. The 12 months of field testing gave rise to little degradation of the sealant coating, except for a few chips and gouge marks on the loading bay surface that were readily repaired. Contamination resulting from radwaste handling was easily removed and the surface was not degraded by contact with the decontamination agents. The field tests were accompanied by a series of laboratory qualification tests carried out at a research laboratory in St. Petersburg. The laboratory tests examined a variety of properties, including bond strength between the coating and the substrate, thermal cycling resistance, wear resistance, flammability, and ease of decontamination. The Polibrid 705 coating met all the Russian Navy qualification requirements with the exception of flammability. In this last instance, it was decided to restrict application of the coating to land-based facilities.

  11. Fine-scale Horizontal Structure of Arctic Mixed-Phase Clouds.

    SciTech Connect (OSTI)

    Rambukkange,M.; Verlinde, J.; Elorante, E.; Luke, E.; Kollias, P.; Shupe, M.

    2006-07-10T23:59:59.000Z

    Recent in situ observations in stratiform clouds suggest that mixed phase regimes, here defined as limited cloud volumes containing both liquid and solid water, are constrained to narrow layers (order 100 m) separating all-liquid and fully glaciated volumes (Hallett and Viddaurre, 2005). The Department of Energy Atmospheric Radiation Measurement Program's (DOE-ARM, Ackerman and Stokes, 2003) North Slope of Alaska (NSA) ARM Climate Research Facility (ACRF) recently started collecting routine measurement of radar Doppler velocity power spectra from the Millimeter Cloud Radar (MMCR). Shupe et al. (2004) showed that Doppler spectra has potential to separate the contributions to the total reflectivity of the liquid and solid water in the radar volume, and thus to investigate further Hallett and Viddaurre's findings. The Mixed-Phase Arctic Cloud Experiment (MPACE) was conducted along the NSA to investigate the properties of Arctic mixed phase clouds (Verlinde et al., 2006). We present surface based remote sensing data from MPACE to discuss the fine-scale structure of the mixed-phase clouds observed during this experiment.

  12. Dome takes a 20% interest in the Arctic pilot project to move LNG

    SciTech Connect (OSTI)

    Richards, B.; Bell, J.

    1980-05-05T23:59:59.000Z

    According to B. Richards of Dome Petroleum Ltd., Dome's interest will be shared with its partially owned subsidiary, Trans-Canada Pipe Lines Ltd. According to J. Bell of Petro-Canada, the operator for the Arctic project, negotiations are under way with Tenneco Inc. for gas sales of up to 225 million cu ft/day to begin in 1985-86. At first, two tankers would ship LNG to a delivery terminal at an as yet unselected site on Canada's east coast, but by 1992, nine ships capable of delivering 1.23 billion cu ft/day of LNG, could be in service. The U.S. and European potential LNG markets amounts to 3-4 trillion cu ft/yr and 3.5-4 trillion cu ft/yr, respectively. Petro-Canada also supports the Polar Gas Ltd. project to lay a gas pipeline from the Arctic Islands and Mackenzie Delta to the south; the projects are not considered to be in competition.

  13. Reconstruction of a high-resolution late holocene arctic paleoclimate record from Colville River delta sediments.

    SciTech Connect (OSTI)

    Schreiner, Kathryn Melissa; Lowry, Thomas Stephen

    2013-10-01T23:59:59.000Z

    This work was partially supported by the Sandia National Laboratories,Laboratory Directed Research and Development' (LDRD) fellowship program in conjunction with Texas A&M University (TAMU). The research described herein is the work of Kathryn M. Schreiner (Katie') and her advisor, Thomas S. Bianchi and represents a concise description of Katie's dissertation that was submitted to the TAMU Office of Graduate Studies in May 2013 in partial fulfillment of her doctorate of philosophy degree. High Arctic permafrost soils contain a massive amount of organic carbon, accounting for twice as much carbon as what is currently stored as carbon dioxide in the atmosphere. However, with current warming trends this sink is in danger of thawing and potentially releasing large amounts of carbon as both carbon dioxide and methane into the atmosphere. It is difficult to make predictions about the future of this sink without knowing how it has reacted to past temperature and climate changes. This project investigated long term, fine scale particulate organic carbon (POC) delivery by the high-Arctic Colville River into Simpson's Lagoon in the near-shore Beaufort Sea. Modern POC was determined to be a mixture of three sources (riverine soils, coastal erosion, and marine). Downcore POC measurements were performed in a core close to the Colville River output and a core close to intense coastal erosion. Inputs of the three major sources were found to vary throughout the last two millennia, and in the Colville River core covary significantly with Alaskan temperature reconstructions.

  14. Brown snow: A long-range transport event in the Canadian Arctic

    SciTech Connect (OSTI)

    Welch, H.E.; Muir, D.C.G.; Billeck, B.N.; Lockhart, W.L.; Brunskill, G.J.; Kling, H.J. (Freshwater Inst., Winnipeg (Canada)); Olson, M.P. (Atmospheric Environment Service, Downsview, Ontario (Canada)); Lemoine, R.M. (Hardy BBT Ltd., Winnipeg, Manitoba (Canada))

    1991-02-01T23:59:59.000Z

    The authors document the occurrence of a long-range transport event that deposited thousands of tons of fine particulates on the District of Keewatin, central Canadian Arctic, {approximately}63 N. Air mass trajectories, clay mineral composition, soot particles, and visible organic remains point to Asian sources for the brown snow material, probably western China. Semivolatile organic pollutants detected in the brown snow included polycyclic aromatic hydrocarbons ({Sigma}PAH), PCB congeners, and DDT-related compounds ({Sigma}DDT), polychlorinated camphenes (PCCs), as well as the herbicide trifuluralin and insecticides methoxychlor, endosulfan, and hexachlorocyclohexane (HCH). {Sigma}PAH, PCB, and PCC concentrations were within the range reported in other studies of Arctic snow but {Sigma}DDT levels were 2-10 times higher than previous reports. High molecular weight PAH may have been associated with soot particles in the brown snow but evidence for Asian sources of the pesticides was not strong because of unknown source signal strengths and possible atmospheric transformations of the compounds. Fluxes of these pollutants were also determined by analyzing sediment cores from two small headwater lakes near the sampling site. The quantities of pollutants deposited in this single event may have comprised a significant fraction (>10%) of total annual input {Sigma}PAH and {Sigma}DDT, as determined from lake sedimentation records.

  15. Correction to ``Stratospheric CO2 isotopic anomalies and SF6 and CFC tracer concentrations in the Arctic

    E-Print Network [OSTI]

    Alexander, Becky

    Correction to ``Stratospheric CO2 isotopic anomalies and SF6 and CFC tracer concentrations anomalies and SF6 and CFC tracer concentrations in the Arctic polar vortex'' [Alexander et al., 2001 of the approx- imate mean SF6 ages versus Á17 O (diamonds) and d18 O (circles). References Alexander, B., M. K

  16. The 2007 Bering Strait oceanic heat flux and anomalous Arctic sea-ice Rebecca A. Woodgate,1

    E-Print Network [OSTI]

    Lindsay, Ron

    flowing PW weakens the ice-pack thereby promoting more sea-ice motion in response to wind, which in turnThe 2007 Bering Strait oceanic heat flux and anomalous Arctic sea-ice retreat Rebecca A. Woodgate,1 sea-ice retreat, we use observational data to estimate Bering Strait volume and heat transports from

  17. JOURNAL OF GEOPHYSICAL RESEARCH, VOL. ???, XXXX, DOI:10.1029/, Age Characteristics in a Multidecadal Arctic Sea Ice1

    E-Print Network [OSTI]

    Bitz, Cecilia

    significant changes, the22 most threatening being a shift from a mostly perennial pack to an ice cover is of fundamental concern for native peoples and wildlife that depend on the pack ice for25 their livelihoods. We do brightness temperatures [Gloersen32 et al., 1992], substantive changes to the Arctic sea ice pack over

  18. 20th-Century Industrial Black Carbon Emissions Altered Arctic Climate Forcing Joseph R. McConnell,

    E-Print Network [OSTI]

    Saltzman, Eric

    in ice cores indicate that sources and concentrations of BC in Greenland precipitation varied greatly, industrial emissions resulted in a seven-fold increase in ice core BC concentrations with most change to 1910, estimated surface climate forcing in early summer from BC in Arctic snow was about 3 W m­2

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

    E-Print Network [OSTI]

    Shupe, Matthew

    A transitioning Arctic surface energy budget: the impacts of solar zenith angle, surface albedo Springer-Verlag 2010 Abstract Snow surface and sea-ice energy budgets were measured near 87.5°N during indicated four distinct tempera- ture regimes, characterized by varying cloud, thermody- namic and solar

  20. Widespread Distribution of Soluble Di-Iron Monooxygenase (SDIMO) Genes in Arctic Groundwater Impacted by 1,4-Dioxane

    E-Print Network [OSTI]

    Alvarez, Pedro J.

    Widespread Distribution of Soluble Di-Iron Monooxygenase (SDIMO) Genes in Arctic Groundwater and propane monooxygenases), are of significant interest due to their potential role in the initiation of 1 bioremediation is precluded by our very limited understanding of the diversity and spatial distribution