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1

Arctic Sea ice model sensitivities.  

SciTech Connect

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 state to internal model parameters. A new sea ice model that holds some promise for improving 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 this MPM sea ice code and compare it with the Los Alamos National Laboratory CICE 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.

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

2010-12-01T23:59:59.000Z

2

Arctic Inversion Strength in Climate Models  

Science Conference Proceedings (OSTI)

Recent work indicates that climate models have a positive bias in the strength of the wintertime low-level temperature inversion over the high-latitude Northern Hemisphere. It has been argued this bias leads to underestimates of the Arctic’s ...

Brian Medeiros; Clara Deser; Robert A. Tomas; Jennifer E. Kay

2011-09-01T23:59:59.000Z

3

Development of a Regional Climate Model of the Western Arctic  

Science Conference Proceedings (OSTI)

An Arctic region climate system model has been developed to simulate coupled interactions among the atmosphere, sea ice, ocean, and land surface of the western Arctic. The atmospheric formulation is based upon the NCAR regional climate model ...

Amanda H. Lynch; William L. Chapman; John E. Walsh; Gunter Weller

1995-06-01T23:59:59.000Z

4

Arctic Precipitation and Evaporation: Model Results and Observational Estimates  

Science Conference Proceedings (OSTI)

Observational estimates of precipitation and evaporation over the Arctic Ocean and its terrestrial watersheds are compared with corresponding values from the climate model simulations of the Atmospheric Model Intercomparison Project (AMIP). ...

John E. Walsh; Vladimir Kattsov; Diane Portis; Valentin Meleshko

1998-01-01T23:59:59.000Z

5

Ocean Heat Transport as a Cause for Model Uncertainty in Projected Arctic Warming  

Science Conference Proceedings (OSTI)

The Arctic climate is governed by complex interactions and feedback mechanisms between the atmosphere, ocean, and solar radiation. One of its characteristic features, the Arctic sea ice, is very vulnerable to anthropogenically caused warming. ...

Irina Mahlstein; Reto Knutti

2011-03-01T23:59:59.000Z

6

Do General Circulation Models Underestimate the Natural Variability in the Arctic Climate?  

Science Conference Proceedings (OSTI)

The authors examine the natural variability of the arctic climate system simulated by two very different models: the Geophysical Fluid Dynamics Laboratory (GFDL) global climate model, and an area-averaged model of the arctic atmosphere–sea ice–...

D. S. Battisti; C. M. Bitz; R. E. Moritz

1997-08-01T23:59:59.000Z

7

An Investigation of an Arctic Front with a Vertically Nested Mesoscale Model  

Science Conference Proceedings (OSTI)

A vertically mesoscale regional numerical weather prediction model is used to simulate an arctic front. The front was observed during the Arctic Cyclone Expedition of 1984. The regional model employs a unique vertical nesting scheme in which the ...

William T. Thompson; Stephen D. Burk

1991-02-01T23:59:59.000Z

8

Modeling the subsurface thermal impact of Arctic thaw lakes in a warming climate  

Science Conference Proceedings (OSTI)

Warming air temperatures in the Arctic are modifying the rates of thermokarst processes along Alaska's Arctic Coastal Plain. The Arctic Coastal Plain is dominated by thaw lakes. These kilometer-scale lakes are the most visible surface features in the ... Keywords: MATLAB, Numerical model, Permafrost, Thaw lakes, Thermal model

N. Matell; R. S. Anderson; I. Overeem; C. Wobus; F. E. Urban; G. D. Clow

2013-04-01T23:59:59.000Z

9

Mesoscale Modeling During Mixed-Phase Arctic Cloud Experiment  

SciTech Connect

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.

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

2005-03-18T23:59:59.000Z

10

How Well Do Regional Climate Models Reproduce Radiation and Clouds in the Arctic? An Evaluation of ARCMIP Simulations  

Science Conference Proceedings (OSTI)

Downwelling radiation in six regional models from the Arctic Regional Climate Model Intercomparison (ARCMIP) project is systematically biased negative in comparison with observations from the Surface Heat Budget of the Arctic Ocean (SHEBA) ...

Michael Tjernström; Joseph Sedlar; Matthew D. Shupe

2008-09-01T23:59:59.000Z

11

Reformulated Gasoline Complex Model  

Gasoline and Diesel Fuel Update (EIA)

Refiners Switch to Reformulated Refiners Switch to Reformulated Gasoline Complex Model Contents * Summary * Introduction o Table 1. Comparison of Simple Model and Complex Model RFG Per Gallon Requirements * Statutory, Individual Refinery, and Compliance Baselines o Table 2. Statutory Baseline Fuel Compositions * Simple Model * Complex Model o Table 3. Complex Model Variables * Endnotes Related EIA Short-Term Forecast Analysis Products * RFG Simple and Complex Model Spreadsheets * Areas Particpating in the Reformulated Gasoline Program * Environmental Regulations and Changes in Petroleum Refining Operations * Oxygenate Supply/Demand Balances in the Short-Term Integrated Forecasting Model * Reformulated Gasoline Foreign Refinery Rules * Demand, Supply, and Price Outlook for Reformulated Motor Gasoline, 1995 , (Adobe

12

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

Science Conference Proceedings (OSTI)

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.

Lettenmaier, Dennis P

2013-04-08T23:59:59.000Z

13

Status of and Outlook for Large-Scale Modeling of Atmosphere–Ice–Ocean Interactions in the Arctic  

Science Conference Proceedings (OSTI)

Arctic air masses have direct impacts on the weather and climatic extremes of midlatitude areas such as central North America. Arctic physical processes pose special and very important problems for global atmospheric models used for climate ...

David Randall; Judith Curry; David Battisti; Gregory Flato; Robert Grumbine; Sirpa Hakkinen; Doug Martinson; Ruth Preller; John Walsh; John Weatherly

1998-02-01T23:59:59.000Z

14

Present-Day Arctic Sea Ice Variability in the Coupled ECHAM5/MPI-OM Model  

Science Conference Proceedings (OSTI)

As a contribution to a detailed evaluation of Intergovernmental Panel on Climate Change (IPCC)-type coupled climate models against observations, this study analyzes Arctic sea ice parameters simulated by the Max-Planck-Institute for Meteorology (...

Nikolay V. Koldunov; Detlef Stammer; Jochem Marotzke

2010-05-01T23:59:59.000Z

15

Remote sensing of freeze-thaw transitions in Arctic soils using the complex resistivity method  

Science Conference Proceedings (OSTI)

Our ability to monitor freeze - thaw transitions is critical to developing a predictive understanding of biogeochemical transitions and carbon dynamics in high latitude environments. In this study, we conducted laboratory column experiments to explore the potential of the complex resistivity method for monitoring the freeze - thaw transitions of the arctic permafrost soils. Samples for the experiment were collected from the upper active layer of Gelisol soils at the Barrow Environmental Observatory, Barrow Alaska. Freeze - thaw transitions were induced through exposing the soil column to controlled temperature environments at 4 C and -20 C. Complex resistivity and temperature measurements were collected regularly during the freeze - thaw transitions using electrodes and temperature sensors installed along the column. During the experiments, over two orders of magnitude of resistivity variations were observed when the temperature was increased or decreased between -20 C and 0 C. Smaller resistivity variations were also observed during the isothermal thawing or freezing processes that occurred near 0 C. Single frequency electrical phase response and imaginary conductivity at 1 Hz were found to be exclusively related to the unfrozen water in the soil matrix, suggesting that these geophysical 24 attributes can be used as a proxy for the monitoring of the onset and progression of the freeze - thaw transitions. Spectral electrical responses and fitted Cole Cole parameters contained additional information about the freeze - thaw transition affected by the soil grain size distribution. Specifically, a shift of the observed spectral response to lower frequency was observed during isothermal thawing process, which we interpret to be due to sequential thawing, first from fine then to coarse particles within the soil matrix. Our study demonstrates the potential of the complex resistivity method for remote monitoring of freeze - thaw transitions in arctic soils. Although conducted at the laboratory scale, this study provides the foundation for exploring the potential of the complex resistivity signals for monitoring spatiotemporal variations of freeze - thaw transitions over field-relevant scales.

Wu, Yuxin [Lawrence Berkeley National Laboratory (LBNL); Hubbard, Susan S [Lawrence Berkeley National Laboratory (LBNL); Ulrich, Craig [Lawrence Berkeley National Laboratory (LBNL); Wullschleger, Stan D [ORNL

2013-01-01T23:59:59.000Z

16

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

SciTech Connect

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.

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

2010-09-01T23:59:59.000Z

17

Comparison of Arctic Climate Simulations by Uncoupled and Coupled Global Models  

Science Conference Proceedings (OSTI)

Simulations of present-day Arctic climate are assessed from suites of 1) 13 global atmosphere-only models from the Atmospheric Model Intercomparison Project (AMIP-II) and 2) 8 coupled atmosphere–ocean–ice models from the Data Distribution Center ...

John E. Walsh; Vladimir M. Kattsov; William L. Chapman; Veronika Govorkova; Tatyana Pavlova

2002-06-01T23:59:59.000Z

18

Performance of the Weather Research and Forecasting Model for Month-Long Pan-Arctic Simulations  

Science Conference Proceedings (OSTI)

The performance of the Weather Research and Forecasting (WRF) model was evaluated for month-long simulations over a large pan-Arctic model domain. The evaluation of seven different WRF (version 3.1) configurations for four months (January, April, ...

John J. Cassano; Matthew E. Higgins; Mark W. Seefeldt

2011-11-01T23:59:59.000Z

19

Mathematical model for ice formation in the Arctic during Alain Pham Ngoc Dinh and Phan Thanh Nam  

E-Print Network (OSTI)

Mathematical model for ice formation in the Arctic during summer Alain Pham Ngoc Dinh and Phan The only source of ice formation in the Arctic during summer is a layer of ice be- tween an under-ice melt-bottoms is governed by both of heat fluxes and salt fluxes. This is a two-phase Stefan problem with two free

20

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

Science Conference Proceedings (OSTI)

The annual energy budget of the Arctic Ocean is characterized by a net heat loss at the air–sea interface that is balanced by oceanic heat transport into the Arctic. Two 150-yr simulations (1950–2099) of a global climate model are used to examine ...

James R. Miller; Gary L. Russell

2002-11-01T23:59:59.000Z

Note: This page contains sample records for the topic "modeling complex arctic" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


21

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

SciTech Connect

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.

Cassano, John [Principal Investigator

2013-06-30T23:59:59.000Z

22

A One-Dimensional Time-Dependent Model for the Vertical Stratification of the Upper Arctic Ocean  

Science Conference Proceedings (OSTI)

A one-dimensional time-dependent model of the upper Arctic Ocean is presented. It describes the circulation above a dynamically passive reservoir of Atlantic water. The model is driven by freshwater runoff from land, ice production and export, ...

Göran Björk

1989-01-01T23:59:59.000Z

23

A Model for the Thickness and Salinity of the Upper Layer in the Arctic Ocean and the Relationship between the Ice Thickness and Some External Parameters  

Science Conference Proceedings (OSTI)

This paper presents a dynamical model for the salinity and thickness of the upper layer in the Arctic. The parameters are the river runoff to the Arctic, the buoyancy supply through the Bering Strait, the export of ice from the Arctic and a ...

Anders Stigebrandt

1981-10-01T23:59:59.000Z

24

Arctic Sea Ice and Freshwater Changes Driven by the Atmospheric Leading Mode in a Coupled Sea Ice–Ocean Model  

Science Conference Proceedings (OSTI)

Observational and modeling studies have indicated recent large changes of sea ice and hydrographic properties in the Arctic Ocean. However, the observational database is sufficiently sparse that the mechanisms responsible for the recent changes ...

Xiangdong Zhang; Moto Ikeda; John E. Walsh

2003-07-01T23:59:59.000Z

25

Fluctuating Arctic Sea Ice Thickness Changes Estimated by an In Situ Learned and Empirically Forced Neural Network Model  

Science Conference Proceedings (OSTI)

Sea ice thickness (SIT) is a key parameter of scientific interest because understanding the natural spatiotemporal variability of ice thickness is critical for improving global climate models. In this paper, changes in Arctic SIT during 1982–2003 ...

G. I. Belchansky; D. C. Douglas; N. G. Platonov

2008-02-01T23:59:59.000Z

26

Mesoscale Modeling of Springtime Arctic Mixed-Phase Stratiform Clouds Using a New Two-Moment Bulk Microphysics Scheme  

Science Conference Proceedings (OSTI)

A new two-moment bulk microphysics scheme is implemented into the polar version of the fifth-generation Pennsylvania State University–NCAR Mesoscale Model (MM5) to simulate arctic mixed-phase boundary layer stratiform clouds observed during ...

H. Morrison; J. O. Pinto

2005-10-01T23:59:59.000Z

27

The Influence of Local Feedbacks and Northward Heat Transport on the Equilibrium Arctic Climate Response to Increased Greenhouse Gas Forcing  

Science Conference Proceedings (OSTI)

This study uses coupled climate model experiments to identify the influence of atmospheric physics [Community Atmosphere Model, versions 4 and 5 (CAM4; CAM5)] and ocean model complexity (slab ocean, full-depth ocean) on the equilibrium Arctic ...

Jennifer E. Kay; Marika M. Holland; Cecilia M. Bitz; Edward Blanchard-Wrigglesworth; Andrew Gettelman; Andrew Conley; David Bailey

2012-08-01T23:59:59.000Z

28

Mechanisms of Decadal Arctic Climate Variability in the Community Climate System Model, Version 2 (CCSM2)  

Science Conference Proceedings (OSTI)

Several mechanisms have been proposed to explain natural climate variability in the Arctic. These include processes related to the influence of the North Atlantic Oscillation/Arctic Oscillation (NAO/AO), anticyclonic/cyclonic regimes, changes in ...

Hugues Goosse; Marika M. Holland

2005-09-01T23:59:59.000Z

29

Arctic and Antarctic Climatology of a GLAS General Circulation Model  

Science Conference Proceedings (OSTI)

The performance of a recent version of the general circulation model used at the Goddard Laboratory for Atmospheric Science is evaluated with particular emphasis on its behavior at high latitudes of the Northern and Southern Hemispheres. A ...

G. F. Herman; W. T. Johnson

1980-12-01T23:59:59.000Z

30

Winter Precipitation Patterns in Arctic Alaska Determined from a Blowing-Snow Model and Snow-Depth Observations  

Science Conference Proceedings (OSTI)

A blowing-snow model (SnowTran-3D) was combined with field measurements of end-of-winter snow depth and density to simulate solid (winter) precipitation, snow transport, and sublimation distributions over a 20?000-km2 arctic Alaska domain. The ...

Glen E. Liston; Matthew Sturm

2002-12-01T23:59:59.000Z

31

Modeling the Effects of Lakes and Wetlands on the Water Balance of Arctic Environments  

Science Conference Proceedings (OSTI)

Lakes, ponds, and wetlands are common features in many low-gradient arctic watersheds. Storage of snowmelt runoff in lakes and wetlands exerts a strong influence on both the interannual and interseasonal variability of northern rivers. This ...

Laura C. Bowling; Dennis P. Lettenmaier

2010-04-01T23:59:59.000Z

32

The Representation of Arctic Soils in the Land Surface Model: The Importance of Mosses  

Science Conference Proceedings (OSTI)

Mosses dominate the surface cover in high northern latitudes and have the potential to play a key role in modifying the thermal and hydrologic regime of Arctic soils. These modifications in turn feed back to influence surface energy exchanges and ...

Jason Beringer; Amanda H. Lynch; F. Stuart Chapin III; Michelle Mack; Gordon B. Bonan

2001-08-01T23:59:59.000Z

33

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)

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

Zuidema, Paquita

34

Arctic house  

E-Print Network (OSTI)

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 ...

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

1999-01-01T23:59:59.000Z

35

Modeling complexity of enterprise routing design  

Science Conference Proceedings (OSTI)

Enterprise networks often have complex routing designs given the need to meet a wide set of resiliency, security and routing policies. In this paper, we take the position that minimizing design complexity must be an explicit objective of routing design. ... Keywords: network complexity, routing design, top-down modeling

Xin Sun; Sanjay G. Rao; Geoffrey G. Xie

2012-12-01T23:59:59.000Z

36

Intrinsic versus Forced Variation in Coupled Climate Model Simulations over the Arctic during the Twentieth Century  

Science Conference Proceedings (OSTI)

There were two major multiyear, Arctic-wide (60°–90°N) warm anomalies (>0.7°C) in land surface air temperature (LSAT) during the twentieth century, between 1920 and 1950 and again at the end of the century after 1979. Reproducing this decadal and ...

Muyin Wang; James E. Overland; Vladimir Kattsov; John E. Walsh; Xiangdong Zhang; Tatyana Pavlova

2007-03-01T23:59:59.000Z

37

The rotation model for the opening of the Canada Basin of the Arctic Ocean pre-  

E-Print Network (OSTI)

stromatolites, giant wave rip- ples, and decameters of pseudomorphosed former aragonite crystal fans, rests Katakturuk Dolomite, as the Cam- brian Saline River Formation rests on the ca. 723 Ma Natkusiak Formation) away from the Cana- dian Arctic islands about a pole in the Mack- enzie River Delta (Hamilton, 1970

Schrag, Daniel

38

Snow–Ground Interface Temperatures in the Kuparuk River Basin, Arctic Alaska: Measurements and Model  

Science Conference Proceedings (OSTI)

Air and snow–ground interface temperatures were measured during two winters at 33 stations spanning the 180-km-long Kuparuk basin in arctic Alaska. Interface temperatures averaged 7.5°C higher than air temperatures and varied in a manner that was ...

Brian Taras; Matthew Sturm; Glen E. Liston

2002-08-01T23:59:59.000Z

39

Sea Ice in the Canadian Arctic Archipelago: Modeling the Past (1950–2004) and the Future (2041–60)  

Science Conference Proceedings (OSTI)

Considering the recent losses observed in Arctic sea ice and the anticipated future warming due to anthropogenic greenhouse gas emissions, sea ice retreat in the Canadian Arctic Archipelago (CAA) is expected and indeed is already being observed. ...

Tessa Sou; Gregory Flato

2009-04-01T23:59:59.000Z

40

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

E-Print Network (OSTI)

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

Solomon, Amy

Note: This page contains sample records for the topic "modeling complex arctic" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


41

Wind and Diffusion Modeling for Complex Terrain  

Science Conference Proceedings (OSTI)

Atmospheric transport and dispersion over complex terrain were investigated. Meteorological and sulfur hexafluoride (SF6) concentration data were collected and used to evaluate the performance of a transport and diffusion model coupled with a ...

Robert M. Cox; John Sontowski; Richard N. Fry Jr.; Catherine M. Dougherty; Thomas J. Smith

1998-10-01T23:59:59.000Z

42

K. Toyota et al.: 3-D modeling of boundary-layer bromine and ozone in the Arctic (Supplement) 1 Supplement to "Analysis of reactive bromine production and ozone  

E-Print Network (OSTI)

K. Toyota et al.: 3-D modeling of boundary-layer bromine and ozone in the Arctic (Supplement) 1 3-D simulations with GEM-AQ: Inference from synoptic-scale patterns" K. Toyota1,2 , J. C. McConnell1. Toyota (kenjiro.toyota@ec.gc.ca) scale forcing resolved well at the grid resolution used in the present

Meskhidze, Nicholas

43

Modeling Snow-Cover Heterogeneity over Complex Arctic Terrain for Regional and Global Climate Models  

Science Conference Proceedings (OSTI)

The small-scale (10 to 100 m) and local-scale (100 m to 10 km) effects of topography (elevation, slope, and aspect) and snow redistribution by wind on the evolution of the snowmelt are investigated. The chosen study area is the 142 km2 Upper ...

Stephen J. Déry; Wade T. Crow; Marc Stieglitz; Eric F. Wood

2004-02-01T23:59:59.000Z

44

Latitudinal distribution of the recent Arctic warming  

Science Conference Proceedings (OSTI)

Increasing Arctic temperature, disappearance of Arctic sea ice, melting of the Greenland ice sheet, sea level rise, increasing strength of Atlantic hurricanes are these impending climate catastrophes supported by observations? Are the recent data really unprecedented during the observational records? Our analysis of Arctic temperature records shows that the Arctic and temperatures in the 1930s and 1940s were almost as high as they are today. We argue that the current warming of the Arctic region is affected more by the multi-decadal climate variability than by an increasing concentration of carbon dioxide. Unfortunately, none of the existing coupled Atmosphere-Ocean General Circulation Models used in the IPCC 2007 cIimate change assessment is able to reproduce neither the observed 20th century Arctic cIimate variability nor the latitudinal distribution of the warming.

Chylek, Petr [Los Alamos National Laboratory; Lesins, Glen K [DALLHOUSIE UNIV.; Wang, Muyin [UNIV OF WASHINGTON

2010-12-08T23:59:59.000Z

45

Coastal Structures Modeling Complex | Open Energy Information  

Open Energy Info (EERE)

Structures Modeling Complex Structures Modeling Complex Jump to: navigation, search Basic Specifications Facility Name Coastal Structures Modeling Complex Overseeing Organization United States Army Corp of Engineers (ERDC) Hydrodynamic Testing Facility Type Wave Basin Length(m) 54.9 Beam(m) 35.4 Depth(m) 1.4 Water Type Freshwater Cost(per day) Contact POC Towing Capabilities Towing Capabilities None Wavemaking Capabilities Wavemaking Capabilities Yes Maximum Wave Height(m) 0.3 Wave Period Range(s) 0.0 Current Velocity Range(m/s) 0.0 Programmable Wavemaking Yes Wave Direction Both Simulated Beach No Channel/Tunnel/Flume Channel/Tunnel/Flume None Wind Capabilities Wind Capabilities None Control and Data Acquisition Description Automated data acquisition and control system Cameras None

46

Simulating Future Changes in Arctic and Subarctic Vegetation  

Science Conference Proceedings (OSTI)

The Arctic is a sensitive system undergoing dramatic changes related to recent warming trends. Vegetation dynamics—increases in the quantity of green vegetation and a northward migration of trees into the arctic tundra—are a component of ... Keywords: Arctic, biogeography, boreal forest, climate change, forest migration, shrub encroachment, subarctic, tundra, vegetation dynamics models

Howard E. Epstein; Jed O. Kaplan; Heike Lischke; Qin Yu

2007-07-01T23:59:59.000Z

47

Refiners Switch to RFG Complex Model  

Reports and Publications (EIA)

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.

Information Center

1998-01-02T23:59:59.000Z

48

Modeling train movements through complex rail networks  

Science Conference Proceedings (OSTI)

Trains operating in densely populated metropolitan areas typically encounter complex trackage configurations. To make optimal use of the available rail capacity, some portions of the rail network may consist of single-track lines while other locations ... Keywords: Trains, deadlock, dispatching, modeling

Quan Lu; Maged Dessouky; Robert C. Leachman

2004-01-01T23:59:59.000Z

49

Bailey, D. A., P. B. Rhines, and S. Hkkinen, 2005: Formation and pathways of North Atlantic Deep Water in a coupled ice-ocean model of the Arctic-North Atlantic Oceans. Climate  

E-Print Network (OSTI)

Water in a coupled ice-ocean model of the Arctic-North Atlantic Oceans. Climate Dyn., 25, doi:10.1007/s. P. Shen, World Scientific, Singapore, 360pp. Yeh, S.- W., and B. P. Kirtman, 2005: Pacific decadal

50

Population Size Does Not Predict Artifact Complexity: Analysis of Data from Tasmania, Arctic Hunter-Gatherers, and Oceania Fishing Groups  

E-Print Network (OSTI)

A, Wachtmeister C-A (2008) Why does human culture increasePOPULATION SIZE DOES NOT PREDICT ARTIFACT COMPLEXITY:interac- tion population and does a task requiring his or

Read, Dwight

2012-01-01T23:59:59.000Z

51

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

SciTech Connect

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.

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

52

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

SciTech Connect

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.

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

53

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

SciTech Connect

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.

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

54

The Arctic Haze Phenomenon  

Science Conference Proceedings (OSTI)

The arctic atmosphere is the repository for surprisingly high concentrations of pollutants throughout the winter months. The polluted air mass in question includes virtually all the atmosphere above the Arctic Circle and also two great lobes that ...

Glenn E. Shaw

1995-12-01T23:59:59.000Z

55

Modeling of Plume Downwash and Enhanced Diffusion near Buildings: Comparison to Wind Tunnel Observations for in Arctic Industrial Site  

Science Conference Proceedings (OSTI)

The ability of a modified Industrial Source Complex model to simulate concentration distributions resulting from high wind speeds (neutral conditions) has been evaluated by comparison to data from a wind tunnel study of a Prudhoe Bay, AK oil-...

Alex Guenther; Brian Lamb; Ronald Petersen

1989-05-01T23:59:59.000Z

56

DOE/SC-ARM-10-034 The Arctic Lower Troposphere Observed  

NLE Websites -- All DOE Office Websites (Extended Search)

since the late 1960s. Inter-model scatter in projected Arctic temperatures is also an order of magnitude larger in the Arctic than in mid- latitudes. Current climate models do...

57

Arctic Ocean circulation patterns revealed by GRACE  

Science Conference Proceedings (OSTI)

Measurements of ocean bottom pressure (OBP) anomalies from the satellite mission GRACE, complemented by information from two ocean models, are used to investigate the variations and distribution of the Arctic Ocean mass from 2002 through 2011. The ...

Cecilia Peralta-Ferriz; James H. Morison; John M. Wallace; Jennifer A. Bonin; Jinlun Zhang

58

An Improved Parameterization for Simulating Arctic Cloud Amount in the CCSM3 Climate Model  

Science Conference Proceedings (OSTI)

A simple alternative parameterization for predicting cloud fraction in the Community Climate System Model, version 3 (CCSM3) global climate model is presented. This formula, dubbed “freeezedry,” is designed to alleviate the bias of excessive low ...

Steve Vavrus; Duane Waliser

2008-11-01T23:59:59.000Z

59

Effects of Stochastic Ice Strength Perturbation on Arctic Finite Element Sea Ice Modeling  

Science Conference Proceedings (OSTI)

The ice strength parameter P* is a key parameter in dynamic/thermodynamic sea ice models that cannot be measured directly. Stochastically perturbing P* in the Finite Element Sea Ice–Ocean Model (FESOM) of the Alfred Wegener Institute aims at ...

Stephan Juricke; Peter Lemke; Ralph Timmermann; Thomas Rackow

2013-06-01T23:59:59.000Z

60

Arctic Mixed-Phase Clouds Simulated by a Cloud-Resolving Model: Comparison with ARM Observations and Sensitivity to Microphysics Parameterizations  

Science Conference Proceedings (OSTI)

Single-layer mixed-phase stratiform (MPS) Arctic clouds, which formed under conditions of large surface heat flux combined with general subsidence during a subperiod of the Atmospheric Radiation Measurement (ARM) Program’s Mixed-Phase Arctic ...

Yali Luo; Kuan-Man Xu; Hugh Morrison; Greg McFarquhar

2008-04-01T23:59:59.000Z

Note: This page contains sample records for the topic "modeling complex arctic" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


61

Numerical Simulations of Observed Arctic Stratus Clouds Using a Second-Order Turbulence Closure Model  

Science Conference Proceedings (OSTI)

A high-resolution one-dimensional version of a second-order turbulence closure radiative-convective model, developed at Los Alamos National Laboratory, is used to simulate the interactions among turbulence, radiation, and bulk cloud parameters in ...

W. S. Smith; C-Y. J. Kao

1996-01-01T23:59:59.000Z

62

Multimodel Combination by a Bayesian Hierarchical Model: Assessment of Ice Accumulation over the Oceanic Arctic Region  

Science Conference Proceedings (OSTI)

The performance of general circulation models (GCMs) varies across regions and periods. When projecting into the future, it is therefore not obvious whether to reject or to prefer a certain GCM. Combining the outputs of several GCMs may enhance ...

Malaak Kallache; Elena Maksimovich; Paul-Antoine Michelangeli; Philippe Naveau

2010-10-01T23:59:59.000Z

63

The Effects of Different Climate Input Datasets on Simulated Carbon Dynamics in the Western Arctic  

Science Conference Proceedings (OSTI)

As part of the Western Arctic Linkage Experiment (WALE), simulations of carbon dynamics in the western Arctic (WALE region) were conducted during two recent decades by driving the Terrestrial Ecosystem Model (TEM) with three alternative climate ...

Joy Clein; A. David McGuire; Eugenie S. Euskirchen; Monika Calef

2007-08-01T23:59:59.000Z

64

Recovery mechanisms of Arctic summer sea ice  

E-Print Network (OSTI)

[1] We examine the recovery of Arctic sea ice from prescribed ice?free summer conditions in simulations of 21st century climate in an atmosphere–ocean general circulation model. We find that ice extent recovers typically within two years. The excess oceanic heat that had built up during the ice?free summer is rapidly returned to the atmosphere during the following autumn and winter, and then leaves the Arctic partly through increased longwave emission at the top of the atmosphere and partly through reduced atmospheric heat advection from lower latitudes. Oceanic heat transport does not contribute significantly to the loss of the excess heat. Our results suggest that anomalous loss of Arctic sea ice during asinglesummerisreversible,astheice–albedo feedback is alleviated by large?scale recovery mechanisms. Hence, hysteretic threshold behavior (or a “tipping point”) is unlikely to occur during the decline of Arctic summer sea?

unknown authors

2011-01-01T23:59:59.000Z

65

NETL: Arctic Energy Office  

NLE Websites -- All DOE Office Websites (Extended Search)

The Arctic Energy Office image showing Alaska landscape Alaska North Slope Resources Alaska Unconventional Resources ChallengesShortages AEO Program Fact Sheet Alaskas fossil...

66

Modelling Complex Fenestration Systems using physical and virtual models  

Science Conference Proceedings (OSTI)

Physical or virtual models are commonly used to visualize the conceptual ideas of architects, lighting designers and researchers; they are also employed to assess the daylighting performance of buildings, particularly in cases where Complex Fenestration Systems (CFS) are considered. Recent studies have however revealed a general tendency of physical models to over-estimate this performance, compared to those of real buildings; these discrepancies can be attributed to several reasons. In order to identify the main error sources, a series of comparisons in-between a real building (a single office room within a test module) and the corresponding physical and virtual models was undertaken. The physical model was placed in outdoor conditions, which were strictly identical to those of the real building, as well as underneath a scanning sky simulator. The virtual model simulations were carried out by way of the Radiance program using the GenSky function; an alternative evaluation method, named Partial Daylight Factor method (PDF method), was also employed with the physical model together with sky luminance distributions acquired by a digital sky scanner during the monitoring of the real building. The overall daylighting performance of physical and virtual models were assessed and compared. The causes of discrepancies between the daylighting performance of the real building and the models were analysed. The main identified sources of errors are the reproduction of building details, the CFS modelling and the mocking-up of the geometrical and photometrical properties. To study the impact of these errors on daylighting performance assessment, computer simulation models created using the Radiance program were also used to carry out a sensitivity analysis of modelling errors. The study of the models showed that large discrepancies can occur in daylighting performance assessment. In case of improper mocking-up of the glazing for instance, relative divergences of 25-40% can be found in different room locations, suggesting that more light is entering than actually monitored in the real building. All these discrepancies can however be reduced by making an effort to carefully mock up the geometry and photometry of the real building. A synthesis is presented in this article which can be used as guidelines for daylighting designers to avoid or estimate errors during CFS daylighting performance assessment. (author)

Thanachareonkit, Anothai; Scartezzini, Jean-Louis [Solar Energy and Building Physics Laboratory (LESO-PB), Ecole Polytechnique Federale de Lausanne (EPFL), CH-1015 Lausanne (Switzerland)

2010-04-15T23:59:59.000Z

67

A Composite Model of Mesoscale Convective Complexes  

Science Conference Proceedings (OSTI)

A composite analysis technique is used to investigate the evolution of mesoscale features of mesoscale convective complexes (MCCs). The early stage of the MCC lifecycle is characterized by convergence, vertical motion and heating being centered ...

William R. Cotton; Ming-Sen Lin; Ray L. McAnelly; Craig J. Tremback

1989-04-01T23:59:59.000Z

68

Modeling the impact of complexity on transportation  

E-Print Network (OSTI)

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 ...

Fernandez, Jose A. (Jose Antonio Fernandez Chavira)

2012-01-01T23:59:59.000Z

69

The Impact of Snow Model Complexity at Three CLPX Sites  

Science Conference Proceedings (OSTI)

Many studies have developed snow process understanding by exploring the impact of snow model complexity on simulation performance. This paper revisits this topic using several recently developed land surface models, including the Simplified ...

Xia Feng; Alok Sahoo; Kristi Arsenault; Paul Houser; Yan Luo; Tara J. Troy

2008-12-01T23:59:59.000Z

70

Robust nite-di erence modelling of complex structures1  

E-Print Network (OSTI)

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

Cerveny, Vlastislav

71

Modeling complex heterogeneous objects with non-manifold heterogeneous cells  

Science Conference Proceedings (OSTI)

This paper presents a new approach to model complex heterogeneous objects with simultaneous geometry intricacies as well as complex material distributions. Different from most of the existing approaches, which utilize manifold B-Rep and the assembly ... Keywords: Attribute based reasoning, Boolean operation, Cellular model, Heterogeneous material, Non-manifold

X. Y. Kou; S. T. Tan; W. S. Sze

2006-05-01T23:59:59.000Z

72

Improvements to the EPA Industrial Source Complex Dispersion Model  

Science Conference Proceedings (OSTI)

Air quality models are a key component in determining air pollution control requirements. The Industrial Source Complex (ISC2) model is a steady-state Gaussian plume model that is used for modeling point, area, volume, and line sources. Since its ...

Dennis G. Atkinson; Desmond T. Bailey; John S. Irwin; Jawad S. Touma

1997-08-01T23:59:59.000Z

73

Representation of Arctic Mixed-Phase clouds and the Wegener-Bergeron-Findeisen Process in Climate Models: Perspectives from a Cloud-Resolving Study  

SciTech Connect

Two types of Arctic mixed-phase clouds observed during the ISDAC and M-PACE field campaigns are simulated using a 3-dimensional cloud-resolving model (CRM) with size-resolved cloud microphysics. The modeled cloud properties agree reasonably well with aircraft measurements and surface-based retrievals. Cloud properties such as the probability density function (PDF) of vertical velocity (w), cloud liquid and ice, the regime of ice growth at the expense of liquid water (i.e., Wegener-Bergeron-Findeisen (WBF) process), and the inherent relationships among cloud properties/processes in the mixed-phase layers are examined to gain insights for improving the representation of the mixed-phase processes in General Circulation Models (GCMs). We find that, the WBF process only occurs in about 50% of the mixed-phase regime with the vast majority occurring in the downdrafts. In updrafts both liquid and ice grow simultaneously. But in GCMs, it is not necessary to treat the WBF process at the subgrid scale. Our CRM results produce a w distribution well represented by a Gaussian normal function, validating, at least for arctic clouds, the subgrid treatment used in GCMs. Our CRM results also support the assumption frequently used in GCMs that mixed phase clouds maintain water vapor very near liquid saturation. A Gamma function with a fixed variance does not accurately represent the subgrid variability of cloud liquid. The PDFs of cloud liquid and cloud ice can be fitted with Gamma functions, and a normal function can be used for total water, but the variance should not be fixed. The relationship between the ice depositional growth rate and cloud ice strongly depends on the capacitance of ice particles. The assumption for the capacitance of ice particles (e.g., 1.0 for spheres) used in GCMs could lead to a large deviation in ice depositional growth. At large sales, the maximum overlap assumption looks appropriate.

Fan, Jiwen; Ghan, Steven J.; Ovchinnikov, Mikhail; Liu, Xiaohong; Rasch, Philip J.; Korolev, Alexei

2011-09-20T23:59:59.000Z

74

Twenty-First-Century Arctic Climate Change in CCSM4  

Science Conference Proceedings (OSTI)

The authors summarize the twenty-first-century Arctic climate simulated by NCAR’s Community Climate System Model, version 4 (CCSM4). Under a strong radiative forcing scenario, the model simulates a much warmer, wetter, cloudier, and stormier ...

Stephen J. Vavrus; Marika M. Holland; Alexandra Jahn; David A. Bailey; Benjamin A. Blazey

2012-04-01T23:59:59.000Z

75

Modeling Power Systems as Complex Adaptive Systems  

Science Conference Proceedings (OSTI)

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.

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

2004-12-30T23:59:59.000Z

76

Environmental and petroleum resource conflicts: a simulation model to determine the benefits of petroleum production in the Arctic National Wildlife Refuge, Alaska  

Science Conference Proceedings (OSTI)

The Arctic National Wildlife Refuge (ANWR), located on the Alaska North Slope, is believed to contain high petroleum production potential. This region also has outstanding wildlife and wilderness values. Currently ANWR is closed to oil and gas leasing. However, Congress is considering an Interior Department recommendation to open a portion of ANWR to oil and gas production. Environmentalists maintain that petroleum exploration and development will have severe environmental impacts. A draft study by the Interior Department reports values that are used to generate an expected present value of the net economic benefits of petroleum development in ANWR of $2.98 billion. Alternatively, using updated oil price projections and revised tax and financial assumptions, the Arctic National Wildlife Refuge Financial Analysis Simulation Model (AFAM) projects the expected present value of net economic benefits of oil production at between $0.32 and $1.39 billion. AFAM results indicate that, within most drilling cost scenarios, oil producers would earn an aftertax profit in 100% of the simulation trials. However, in a high-cost drilling scenario, AFAM projects aftertax losses to oil producers in 45% of the simulation trials. Although the Interior Department does not report a range of net economic benefits from oil development of ANWR, AFAM indicates that the distribution of net economic benefits across all scenarios is positively skewed. Net economic benefits from oil development range from $0 to $4.75 billion with a greater probability of benefits closer to the lower value. Decision makers considering whether or not to open ANWR to petroleum development can use these values to judge if the economic benefits outweigh the projected negative wilderness and wildlife impacts. 10 references, 9 figures, 6 tables.

Goerold, W.T.

1987-01-01T23:59:59.000Z

77

An energy complexity model for algorithms  

Science Conference Proceedings (OSTI)

Energy consumption has emerged as a first class computing resource for both server systems and personal computing devices. The growing importance of energy has led to rethink in hardware design, hypervisors, operating systems and compilers. Algorithm ... Keywords: energy efficient algorithms, parallel disk i/o model

Swapnoneel Roy; Atri Rudra; Akshat Verma

2013-01-01T23:59:59.000Z

78

Computational Modeling of Uranium Hydriding and Complexes  

DOE Green Energy (OSTI)

Uranium hydriding is one of the most important processes that has received considerable attention over many years. Although many experimental and modeling studies have been carried out concerning thermochemistry, diffusion kinetics and mechanisms of U-hydriding, very little is known about the electronic structure and electronic features that govern the U-hydriding process. Yet it is the electronic feature that controls the activation barrier and thus the rate of hydriding. Moreover the role of impurities and the role of the product UH{sub 3} on hydriding rating are not fully understood. An early study by Condon and Larson concerns with the kinetics of U-hydrogen system and a mathematical model for the U-hydriding process. They proposed that diffusion in the reactant phase by hydrogen before nucleation to form hydride phase and that the reaction is first order for hydriding and zero order for dehydriding. Condon has also calculated and measures the reaction rates of U-hydriding and proposed a diffusion model for the U-hydriding. This model was found to be in excellent agreement with the experimental reaction rates. From the slopes of the Arrhenius plot the activation energy was calculated as 6.35 kcal/mole. In a subsequent study Kirkpatrick formulated a close-form for approximate solution to Condon's equation. Bloch and Mintz have proposed the kinetics and mechanism for the U-H reaction over a wide range of pressures and temperatures. They have discussed their results through two models, one, which considers hydrogen diffusion through a protective UH{sub 3} product layer, and the second where hydride growth occurs at the hydride-metal interface. These authors obtained two-dimensional fits of experimental data to the pressure-temperature reactions. Kirkpatrick and Condon have obtained a linear solution to hydriding of uranium. These authors showed that the calculated reaction rates compared quite well with the experimental data at a hydrogen pressure of 1 atm. Powell et al. have studied U-hydriding in ultrahigh vacuum and obtained the linear rate data over a wide range of temperatures and pressures. They found reversible hydrogen sorption on the UH{sub 3} reaction product from kinetic effects at 21 C. This demonstrates restarting of the hydriding process in the presence of UH{sub 3} reaction product. DeMint and Leckey have shown that Si impurities dramatically accelerate the U-hydriding rates. We report our recent results of relativistic computations that vary from complete active space multi-configuration interaction (CAS-MCSCF) followed by multi-reference configuration interaction (MRSDCI) computations that included up to 50 million configurations for modeling of uranium-hydriding with cluster models will be presented.

Balasubramanian, K; Siekhaus, W J; McLean, W

2003-02-03T23:59:59.000Z

79

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

SciTech Connect

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.

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

80

Arctic Solar | Open Energy Information  

Open Energy Info (EERE)

search Name Arctic Solar Place G"LLIVARE, Sweden Zip SE- 98228 Product manufacturers of PV modules References Arctic Solar1 LinkedIn Connections CrunchBase Profile No...

Note: This page contains sample records for the topic "modeling complex arctic" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


81

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

SciTech Connect

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.

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

82

Drilling into Complex 3D Models with Gimlenses Cyprien Pindat  

E-Print Network (OSTI)

-Neira et al. 1992]. For instance, Boeing's 777 air- liner was entirely modeled using CAD software into complex 3D models with gimlenses. In Proceedings of the 19th ACM Symposium on Virtual Reality Software and Technology (VRST '13). ACM. 223-230. c ACM, 2013. This is the author's version of the work. It is posted here

Recanati, Catherine

83

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

SciTech Connect

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.

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

2009-02-27T23:59:59.000Z

84

Review of Science Issues, Deployment Strategy, and Status for the ARM North Slope of Alaska–Adjacent Arctic Ocean Climate Research Site  

Science Conference Proceedings (OSTI)

Recent climate modeling results point to the Arctic as a region that is particularly sensitive to global climate change. The Arctic warming predicted by the models to result from the expected doubling of atmospheric carbon dioxide is two to three ...

K. Stamnes; R. G. Ellingson; J. A. Curry; J. E. Walsh; B. D. Zak

1999-01-01T23:59:59.000Z

85

CONTENTS Developing Alaskan Arctic  

NLE Websites -- All DOE Office Websites (Extended Search)

Developing Alaskan Arctic Developing Alaskan Arctic Potential ...........................................1 Commentary ...................................2 NETL Develops Strategic Partnership with the Alaska Center for Energy and Power ...8 Deepwater and Ultra-Deepwater Produced Water Discharge ....10 Intelligent Production System for Ultra Deepwater with Short Hop Wireless Power and Wireless Data Transfer .........................................16 Snapshots ......................................19 CONTACTS Roy Long Technology Manager Ultra-Deepwater/Offshore 304-285-4479 roy.long@netl.doe.gov Ray Boswell Technology Manager Natural Gas Technology R&D 412-386-7614 ray.boswell@netl.doe.gov Eric Smistad Technology Manager Oil Technology R&D 281-494-2619 eric.smistad@netl.doe.gov

86

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

E-Print Network (OSTI)

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 ...

Monier, Erwan

87

Arctic ice islands  

SciTech Connect

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.

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

1988-01-01T23:59:59.000Z

88

Statistical Analysis of Forecasting Models across the North Slope of Alaska during the Mixed-Phase Arctic Clouds Experiment  

Science Conference Proceedings (OSTI)

The National Centers for Environmental Prediction’s (NCEP) Eta Model, the models of the European Centre for Medium-Range Weather Forecasts (ECMWF) and the National Aeronautics and Space Administration’s (NASA) Global Modeling and Assimilation ...

Victor T. Yannuzzi; Eugene E. Clothiaux; Jerry Y. Harrington; Johannes Verlinde

2009-12-01T23:59:59.000Z

89

Why sequence arctic algae for alternative energy?  

NLE Websites -- All DOE Office Websites (Extended Search)

arctic algae for alternative energy? Five different protists representing different algal classes isolated from the Arctic Ocean are being investigated for adaptation to perennial...

90

Plant roots in arctic tundra  

DOE Data Explorer (OSTI)

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

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

91

Information Society: Modeling A Complex System With Scarce Data  

E-Print Network (OSTI)

Considering electronic implications in the Information Society (IS) as a complex system, complexity science tools are used to describe the processes that are seen to be taking place. The sometimes troublesome relationship between the information and communication new technologies and e-society gives rise to different problems, some of them being unexpected. Probably, the Digital Divide (DD) and the Internet Governance (IG) are among the most conflictive ones of internationally based e-Affairs. Admitting that solutions should be found for these problems, certain international policies are required. In this context, data gathering and subsequent analysis, as well as the construction of adequate physical models are extremely important in order to imagine different future scenarios and suggest some subsequent control. In the main text, mathematical modelization helps for visualizing how policies could e.g. influence the individual and collective behavior in an empirical social agent system. In order to show how t...

Olivera, Noemi L; Ausloos, Marcel

2012-01-01T23:59:59.000Z

92

NETL: Arctic Energy Office  

NLE Websites -- All DOE Office Websites (Extended Search)

Facts/Issues Facts/Issues Average South-Central natural gas consumption in 2005 was: 13.9% gas utility 20.0% power generation 54.3% industrial-LNG sales, oil refining, and fertilizer manufacturing 7.2% field operations 4.6% other Due to a lack of natural gas deliverability, the Cook Inlet fertilizer plant terminated operations in May 2008. LNG sales are increasingly curtailed during cold weather due to peak demand shortages. The LNG export license is up for renewal in 2011. Exploration must find new reserves on the order of 500 Bcf, and that will only solve the natural gas shortage until approximately 2019. Challenges Natural gas in the Arctic, until recently, has been largely overlooked. Little is known about the possible breadth of the Arctic storehouse of natural gas apart from the resource associated with the currently producing

93

Arctic Energy Office  

NLE Websites -- All DOE Office Websites (Extended Search)

O O G R A M FAC T S Strategic Center for Natural Gas & Oil CONTACTS Joel Lindstrom Arctic Energy Office National Energy Technology Laboratory 420 L Street, Suite 305 Anchorage, Alaska 99501 907-271-3618 joel.lindstrom@contr.netl.doe.gov Albert B. Yost II Sr. Management Technical Advisor Strategic Center for Natural Gas & Oil National Energy Technology Laboratory 3610 Collins Ferry Road Morgantown, WV 26507-0880 304-285-4479 albert.yost@netl.doe.gov

94

CTDMPLUS: A Dispersion Model for Sources near Complex Topography. Part I: Technical Formulations  

Science Conference Proceedings (OSTI)

The Complex Terrain Dispersion Model (CTDMPLUS), a point-source, steady-state model for complex-terrain applications, is described. The model simulates the flow and plume distortion near user-selected, three-dimensional terrain features, yet ...

Steven G. Perry

1992-07-01T23:59:59.000Z

95

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

E-Print Network (OSTI)

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

Doran, Simon J.

96

Considerations in the Selection of Global Climate Models for Regional Climate Projections: The Arctic as a Case Study  

Science Conference Proceedings (OSTI)

Climate projections at regional scales are in increased demand from management agencies and other stakeholders. While global atmosphere–ocean climate models provide credible quantitative estimates of future climate at continental scales and above,...

James E. Overland; Muyin Wang; Nicholas A. Bond; John E. Walsh; Vladimir M. Kattsov; William L. Chapman

2011-03-01T23:59:59.000Z

97

Source and Pathway of the Western Arctic Upper Halocline in a Data-Constrained Coupled Ocean and Sea Ice Model  

E-Print Network (OSTI)

A coupled ocean and sea ice model is used to investigate dense water (DW) formation in the Chukchi and Bering shelves and the pathways by which this water feeds the upper halocline. Two 1992–2008 data-constrained solutions ...

Nguyen, An T.

98

Source and Pathway of the Western Arctic Upper Halocline in a Data-Constrained Coupled Ocean and Sea Ice Model  

Science Conference Proceedings (OSTI)

A coupled ocean and sea ice model is used to investigate dense water (DW) formation in the Chukchi and Bering shelves and the pathways by which this water feeds the upper halocline. Two 1992–2008 data-constrained solutions at 9- and 4-km ...

An T. Nguyen; Ronald Kwok; Dimitris Menemenlis

2012-05-01T23:59:59.000Z

99

Optimization of a Sea Ice Model Using Basinwide Observations of Arctic Sea Ice Thickness, Extent, and Velocity  

Science Conference Proceedings (OSTI)

A stand-alone sea ice model is tuned and validated using satellite-derived, basinwide observations of sea ice thickness, extent, and velocity from the years 1993 to 2001. This is the first time that basin-scale measurements of sea ice thickness ...

Paul A. Miller; Seymour W. Laxon; Daniel L. Feltham; Douglas J. Cresswell

2006-04-01T23:59:59.000Z

100

On the circulation of Atlantic Water in the Arctic Ocean  

Science Conference Proceedings (OSTI)

An idealized eddy-resolving numerical model and an analytic three-layer model are used to develop ideas about what controls the circulation of Atlantic Water in the Arctic Ocean. The numerical model is forced with a surface heat flux, uniform ...

Michael A. Spall

Note: This page contains sample records for the topic "modeling complex arctic" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


101

Impacts of Land Surface Model Complexity on a Regional Simulation of a Tropical Synoptic Event  

Science Conference Proceedings (OSTI)

A multimode Chameleon Surface Model (CHASM) with different levels of complexity in parameterizing surface energy balance is coupled to a limited-area model (DARLAM) to investigate the impacts of complexity in land surface representations on the ...

H. Zhang; J. L. McGregor; A. Henderson-Sellers; J. J. Katzfey

2004-02-01T23:59:59.000Z

102

ATP-Induced Shape Change in a Model Protein Complexed in ...  

Science Conference Proceedings (OSTI)

ATP-Induced Shape Change in a Model Protein Complexed in Chaperonins. The role of molecular chaperones in mediating ...

103

Complex Geometry Creation and Turbulent Conjugate Heat Transfer Modeling  

Science Conference Proceedings (OSTI)

The multiphysics capabilities of COMSOL provide the necessary tools to simulate the turbulent thermal-fluid aspects of the High Flux Isotope Reactor (HFIR). Version 4.1, and later, of COMSOL provides three different turbulence models: the standard k-{var_epsilon} closure model, the low Reynolds number (LRN) k-{var_epsilon} model, and the Spalart-Allmaras model. The LRN meets the needs of the nominal HFIR thermal-hydraulic requirements for 2D and 3D simulations. COMSOL also has the capability to create complex geometries. The circular involute fuel plates used in the HFIR require the use of algebraic equations to generate an accurate geometrical representation in the simulation environment. The best-estimate simulation results show that the maximum fuel plate clad surface temperatures are lower than those predicted by the legacy thermal safety code used at HFIR by approximately 17 K. The best-estimate temperature distribution determined by COMSOL was then used to determine the necessary increase in the magnitude of the power density profile (PDP) to produce a similar clad surface temperature as compared to the legacy thermal safety code. It was determined and verified that a 19% power increase was sufficient to bring the two temperature profiles to relatively good agreement.

Bodey, Isaac T [ORNL; Arimilli, Rao V [ORNL; Freels, James D [ORNL

2011-01-01T23:59:59.000Z

104

Sensitivity of Arctic Climate Variability to Mean State: Insights from the Cretaceous  

Science Conference Proceedings (OSTI)

This study investigates Arctic climate variability during a period of extreme warmth using the Community Climate System Model, version 3 (CCSM3) coupled ocean–atmosphere general circulation model. Four mid-Cretaceous simulations were completed ...

Christopher J. Poulsen; Jing Zhou

2013-09-01T23:59:59.000Z

105

Numerical Modeling of Complex Porous Media For Borehole Applications  

E-Print Network (OSTI)

The diffusion/relaxation behavior of polarized spins of pore filling fluid, as often probed by NMR relaxometry, is widely used to extract information on the pore-geometry. Such information is further interpreted as an indicator of the key transport property of the formation in the oil industry. As the importance of reservoirs with complex pore geometry grows, so does the need for deeper understanding of how these properties are inter-related. Numerical modeling of relevant physical processes using a known pore geometry promises to be an effective tool in such endeavor. Using a suite of numerical techniques based on random-walk (RW) and Lattice-Boltzmann (LB) algorithms, we compare sandstone and carbonate pore geometries in their impact on NMR and flow properties. For NMR relaxometry, both laboratory measurement and simulation were done on the same source to address some of the long-standing issues in its borehole applications. Through a series of "numerical experiments" in which the interfacial relaxation properties of the pore matrix is varied systematically, we study the effect of a variable surface relaxivity while fully incorporating the complexity of the pore geometry. From combined RW and LB simulations, we also obtain diffusion-convection propagator and compare the result with experimental and network-simulation counterparts.

Seungoh Ryu; Weishu Zhao; Gabriela Leu; Philip M. Singer; Hyung Joon Cho; Youngseuk Keehm

2009-08-13T23:59:59.000Z

106

Springtime Visibility in the Arctic  

Science Conference Proceedings (OSTI)

Since the Ptarmigan flights in the 1950s, the springtime visibility reduction in the Arctic has been identified with pollution aerosol. However, observed values of the dry aerosol extinction coefficient are too small to explain the observed ...

F. G. Meyer; J. A. Curry; C. A. Brock; L. F. Radke

1991-03-01T23:59:59.000Z

107

Synoptically Driven Arctic Winter States  

Science Conference Proceedings (OSTI)

The dense network of the Surface Heat Budget of the Arctic (SHEBA) observations is used to assess relationships between winter surface and atmospheric variables as the SHEBA site came under the influence of cyclonic and anticyclonic atmospheric ...

Kirstie Stramler; Anthony D. Del Genio; William B. Rossow

2011-03-01T23:59:59.000Z

108

Complexity management through product portfolio cost modeling and optimization  

E-Print Network (OSTI)

A significant amount of complexity exists within the brand and product portfolios of PharmaCo. This complexity is driven by several factors: first, medical needs for differing products and dosages; second, marketing requests ...

Sommerkorn, Peter (Peter Wilford)

2013-01-01T23:59:59.000Z

109

Evaluating a Hybrid Prognostic–Diagnostic Model That Improves Wind Forecast Resolution in Complex Coastal Topography  

Science Conference Proceedings (OSTI)

The results from a hybrid approach that combines the forecasts of a mesoscale model with a diagnostic wind model to produce high-resolution wind forecasts in complex coastal orography are evaluated. The simple diagnostic wind model [Winds on ...

Francis L. Ludwig; Douglas K. Miller; Shawn G. Gallaher

2006-01-01T23:59:59.000Z

110

Overview of Arctic Cloud and Radiation Characteristics  

Science Conference Proceedings (OSTI)

To provide a background for ARM's activities at the North Slope of Alaska/Adjacent Arctic Ocean sites, an overview is given of our current state of knowledge of Arctic cloud and radiation properties and processes. The authors describe the Arctic ...

Judith A. Curry; Julie L. Schramm; William B. Rossow; David Randall

1996-08-01T23:59:59.000Z

111

Factors Influencing Simulated Changes in Future Arctic Cloudiness  

Science Conference Proceedings (OSTI)

This study diagnoses the changes in Arctic clouds simulated by the Community Climate System Model version 3 (CCSM3) in a transient 2 × CO2 simulation. Four experiments—one fully coupled and three with prescribed SSTs and/or sea ice cover—are used ...

Stephen J. Vavrus; Uma S. Bhatt; Vladimir A. Alexeev

2011-09-01T23:59:59.000Z

112

NRELs System Advisor Model Simplifies Complex Energy Analysis...  

NLE Websites -- All DOE Office Websites (Extended Search)

to traditional power sources, decision makers can choose among solar, wind, and geothermal technologies as well. Each of these technologies has complex performance...

113

Crude Oil Price Forecasting: A Transfer Learning Based Analog Complexing Model  

Science Conference Proceedings (OSTI)

Most of the existing models for oil price forecasting only use the data in the forecasted time series itself. This study proposes a transfer learning based analog complexing model (TLAC). It first transfers some related time series in source domain to ... Keywords: transfer learning method, analog complexing model, genetic algorithm, crude oil price forecasting

Jin Xiao; Changzheng He; Shouyang Wang

2012-08-01T23:59:59.000Z

114

A Characterization of the Present-Day Arctic Atmosphere in CCSM4  

Science Conference Proceedings (OSTI)

Simulation of key features of the Arctic atmosphere in the Community Climate System Model, version 4 (CCSM4) is evaluated against observational and reanalysis datasets for the present-day (1981–2005). Surface air temperature, sea level pressure, ...

Gijs de Boer; William Chapman; Jennifer E. Kay; Brian Medeiros; Matthew D. Shupe; Steve Vavrus; John Walsh

2012-04-01T23:59:59.000Z

115

Impact of Daily Arctic Sea Ice Variability in CAM3.0 during Fall and Winter  

Science Conference Proceedings (OSTI)

Climate projections suggest that an ice-free summer Arctic Ocean is possible within several decades and with this comes the prospect of increased ship traffic and safety concerns. The daily sea ice concentration tendency in five Coupled Model ...

Dyre O. Dammann; Uma S. Bhatt; Peter L. Langen; Jeremy R. Krieger; Xiangdong Zhang

2013-03-01T23:59:59.000Z

116

Future Projections of Landfast Ice Thickness and Duration in the Canadian Arctic  

Science Conference Proceedings (OSTI)

Projections of future landfast ice thickness and duration were generated for nine sites in the Canadian Arctic and one site on the Labrador coast with a simple downscaling technique that used a one-dimensional sea ice model driven by ...

J. A. Dumas; G. M. Flato; R. D. Brown

2006-10-01T23:59:59.000Z

117

Toward an Explanation of the Annual Cycle of Cloudiness over the Arctic Ocean  

Science Conference Proceedings (OSTI)

The annual cycle of low cloud amount over the Arctic Ocean is examined using climatological data and a radiative-turbulent column model. Three hypotheses for the annual cycle are formulated, compared with climatological data for consistency, and ...

J. A. Beesley; R. E. Moritz

1999-02-01T23:59:59.000Z

118

Turbulence Structure of Arctic Stratus Clouds Derived from Measurements and Calculations  

Science Conference Proceedings (OSTI)

Results are presented from a detailed case study of an Arctic stratus cloud over the Fram Strait that is based on aircraft measurements and model calculations. The measurements have been performed during MIZEX 1984 (Marginal Ice Zone Experiment) ...

Jörg E. Finger; Peter Wendling

1990-06-01T23:59:59.000Z

119

Remote Sensing of Surface and Cloud Properties in the Arctic from AVHRR Measurements  

Science Conference Proceedings (OSTI)

Algorithms to retrieve cloud optical depth and effective radius in the Arctic using Advanced Very High Resolution Radiometer (AVHRR) data are developed, using a comprehensive radiative transfer model in which the atmosphere is coupled to the ...

W. Han; K. Stamnes; Dan Lubin

1999-07-01T23:59:59.000Z

120

The Changing Cryosphere: Pan-Arctic Snow Trends (1979–2009)  

Science Conference Proceedings (OSTI)

Arctic snow presence, absence, properties, and water amount are key components of Earth’s changing climate system that incur far-reaching physical and biological ramifications. Recent dataset and modeling developments permit relatively high-...

Glen E. Liston; Christopher A. Hiemstra

2011-11-01T23:59:59.000Z

Note: This page contains sample records for the topic "modeling complex arctic" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


121

Sensitivity of CAM5-Simulated Arctic Clouds and Radiation to Ice Nucleation Parameterization  

Science Conference Proceedings (OSTI)

Sensitivity of Arctic clouds and radiation in the Community Atmospheric Model, version 5, to the ice nucleation process is examined by testing a new physically based ice nucleation scheme that links the variation of ice nuclei (IN) number ...

Shaocheng Xie; Xiaohong Liu; Chuanfeng Zhao; Yuying Zhang

2013-08-01T23:59:59.000Z

122

Complex event processing model for distributed RFID network  

Science Conference Proceedings (OSTI)

RFID complex event processing technology, which is proved to be a powerful tool in describing relationship between different events, such as timing, causality, and membership in RFID data streams or events, is a key point of RFID researching in these ... Keywords: RFID, RFID network, complex event processing

Xiao Jia; Yuan Wenming; Wang Dong

2009-11-01T23:59:59.000Z

123

A task-based model of perceived website complexity  

Science Conference Proceedings (OSTI)

In this study, we propose that perceived website complexity (PWC) is central to understanding how sophisticated features of a website (such as animation, audio, video, and rollover effects) affect a visitor's experience at the site. Although previous ... Keywords: perceived website complexity, user perception, website usability

Sucheta Nadkarni; Reetika Gupta

2007-09-01T23:59:59.000Z

124

The Necklace around the Arctic Arctic indigenous peoples  

E-Print Network (OSTI)

national choir). #12;The economies of the Arctic settlements invariably involve fish, oil or gas: natural in the 1002 area. This work was undertaken by a private exploration firm and funded by a group of oil exploration apparently began abruptly in A.D. 793 with an attack on Lindesfarne, an island off the NE

125

Sensitivity of Annual Evaporation to Soil and Root Properties in Two Models of Contrasting Complexity  

Science Conference Proceedings (OSTI)

Simulations of soil water and evapotranspiration with physically based models at broad scales vary in both complexity of processes modeled and in parameterization of soil and root properties. Sensitivity of annual evaporation Eann to some of ...

C. A. Federer; C. Vörösmarty; B. Fekete

2003-12-01T23:59:59.000Z

126

Limited-Area Model Sensitivity to the Complexity of Representation of the Land Surface Energy Balance  

Science Conference Proceedings (OSTI)

By coupling a multimode land surface scheme with a regional climate model, three scientific issues are addressed in this paper: (i) the regional model's sensitivity to the different levels of complexity presented by the land surface ...

H. Zhang; A. Henderson-Sellers; A. J. Pitman; C. E. Desborough; J. L. McGregor; J. J. Katzfey

2001-10-01T23:59:59.000Z

127

Complexes  

DOE Green Energy (OSTI)

Iron L-edge, iron K-edge, and sulfur K-edge X-ray absorption spectroscopy was performed on a series of compounds [Fe{sup III}H{sub 3}buea(X)]{sup n-} (X = S{sup 2-}, O{sup 2-}, OH{sup -}). The experimentally determined electronic structures were used to correlate to density functional theory calculations. Calculations supported by the data were then used to compare the metal-ligand bonding and to evaluate the effects of H-bonding in Fe{sup III}-O vs Fe{sup III-}S complexes. It was found that the Fe{sup III-}O bond, while less covalent, is stronger than the FeIII-S bond. This dominantly reflects the larger ionic contribution to the Fe{sup III-}O bond. The H-bonding energy (for three H-bonds) was estimated to be -25 kcal/mol for the oxo as compared to -12 kcal/mol for the sulfide ligand. This difference is attributed to the larger charge density on the oxo ligand resulting from the lower covalency of the Fe-O bond. These results were extended to consider an Fe{sup IV-}O complex with the same ligand environment. It was found that hydrogen bonding to Fe{sup IV-}O is less energetically favorable than that to Fe{sup III-}O, which reflects the highly covalent nature of the Fe{sup IV-}O bond.

Dey, Abhishek; Hocking, Rosalie K.; /Stanford U., Chem. Dept.; Larsen, Peter; Borovik, Andrew S.; /Kansas U.; Hodgson, Keith O.; Hedman, Britt; Solomon, Edward I.; /SLAC,

2006-09-27T23:59:59.000Z

128

A DSS Design Model for complex problems: Lessons from mission critical infrastructure  

Science Conference Proceedings (OSTI)

This paper presents a new DSS Design Model for complex, mission critical decision-making situations and its technical, conceptual, and partial empirical evaluation. The new model was derived from conceptual design research and through a deep qualitative ... Keywords: Complex adaptive systems, Decision support systems, Design, Electricity, Infrastructure, Knowledge management, Wicked decisions

Robb Klashner; Sameh Sabet

2007-04-01T23:59:59.000Z

129

Proceedings of the 2008 Workshop on Complex Systems Modelling and Simulation  

E-Print Network (OSTI)

Proceedings of the 2008 Workshop on Complex Systems Modelling and Simulation CoSMoS 2008 #12;. #12 system, without permission in writing from the copyright holder. ISBN-10: 1-905986-17-3 ISBN-13: 978. Complex Systems often involve a large num- ber of agents, which can be modelled as processes

Augusto, Juan Carlos

130

Instantaneous current modeling in a complex VLIW processor core  

Science Conference Proceedings (OSTI)

Measuring and modeling instantaneous current consumption or current dynamics of a processor is important in embedded system designs, wireless communications, low-energy mobile computing, security of communications, and reliability. In this paper, we ... Keywords: Instruction-level current model, current and power measurement in a processor, instantaneous current model, power and energy model

Radu Muresan; Catherine Gebotys

2005-05-01T23:59:59.000Z

131

Precipitation Shifts over Western North America as a Result of Declining Arctic Sea Ice Cover: The Coupled System Response  

Science Conference Proceedings (OSTI)

Changes in Arctic sea ice cover have the potential to impact midlatitude climate. A previous sensitivity study utilizing the National Center for Atmospheric Research’s (NCAR) atmospheric general circulation model [AGCM; Community Climate Model, ...

Jacob O. Sewall

2005-12-01T23:59:59.000Z

132

Short-Term Climatic Variability of the Arctic  

Science Conference Proceedings (OSTI)

The circulation of the Arctic atmosphere undergoes large fluctuations about its monthly and annual means. The statistics of Arctic sea level pressure and temperature are evaluated in order to place Arctic atmospheric variability into the context ...

John E. Walsh; William L. Chapman

1990-02-01T23:59:59.000Z

133

An accelerating rendering method of hybrid point and polygon for complex three-dimensional models  

Science Conference Proceedings (OSTI)

This paper presents an accelerating hybrid rendering method for complex three-dimensional models using both points and polygons. In circumstance of current PC hardware, our rendering method that integrates advantages of both GBMR (Graphics -Based Modeling ... Keywords: continuous multi-resolution models, modeling and rendering, point clouds, real-time property, virtual reality

Aimin Hao; Guifen Tian; Qinping Zhao; Zhide Li

2006-11-01T23:59:59.000Z

134

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

DOE Green Energy (OSTI)

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).

Not Available

2011-10-01T23:59:59.000Z

135

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

U.S. Energy Information Administration (EIA)

1. Overview of the Arctic National Wildlife Refuge. Background. The Arctic National Wildlife Refuge (ANWR) 1002 Area of the Alaska North Slope represents an area ...

136

The ecology of Arctic cod (Boreogadus saida) and interactions with seabirds, seals, and whales in the Canadian Arctic.  

E-Print Network (OSTI)

??This thesis investigates the foraging of Arctic cod (Boreogadus saida) and its predators during the summer in the Canadian Arctic. Findings included the identification of… (more)

Matley, Jordan

2012-01-01T23:59:59.000Z

137

A Physically Based Daily Hydrometeorological Model for Complex Mountain Terrain  

Science Conference Proceedings (OSTI)

This paper describes the continued development of the physically based hydrometeorological model Generate Earth Systems Science input (GENESYS) and its application in simulating snowpack in the St. Mary (STM) River watershed, Montana. GENESYS is ...

Ryan J. MacDonald; James M. Byrne; Stefan W. Kienzle

2009-12-01T23:59:59.000Z

138

Climate Determinism Revisited: Multiple Equilibria in a Complex Climate Model  

E-Print Network (OSTI)

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 ...

Ferreira, David

139

Climate Determinism Revisited: Multiple Equilibria in a Complex Climate Model  

Science Conference Proceedings (OSTI)

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 parameters and external ...

David Ferreira; John Marshall; Brian Rose

2011-02-01T23:59:59.000Z

140

A Complex Systems Modelling Approach for Decentralised Simulation of Electrical Microgrids  

Science Conference Proceedings (OSTI)

The structure and behaviour of Electrical Grids share many of the properties of Complex Computer Systems, with microgrids and other decentralised electrical systems attached to them, so they can be interpreted as Systems of Systems. Furthermore, the ... Keywords: electrical grid, microgrid, agent-based models, complex computer systems, systems of systems

Enrique Kremers; Pablo Viejo; Oscar Barambones; Jose Gonzalez de Durana

2010-03-01T23:59:59.000Z

Note: This page contains sample records for the topic "modeling complex arctic" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


141

Modelling excitonic-energy transfer in light-harvesting complexes  

E-Print Network (OSTI)

The theoretical and experimental study of energy transfer in photosynthesis has revealed an interesting transport regime, which lies at the borderline between classical transport dynamics and quantum-mechanical interference effects. Dissipation is caused by the coupling of electronic degrees of freedom to vibrational modes and leads to a directional energy transfer from the antenna complex to the target reaction-center. The dissipative driving is robust and does not rely on fine-tuning of specific vibrational modes. For the parameter regime encountered in the biological systems new theoretical tools are required to directly compare theoretical results with experimental spectroscopy data. The calculations require to utilize massively parallel graphics processor units (GPUs) for efficient and exact computations.

Kramer, Tobias

2013-01-01T23:59:59.000Z

142

Including cognitive biases and distance-based rewards in a connectionist model of complex problem solving  

Science Conference Proceedings (OSTI)

We present a cognitive, connectionist-based model of complex problem solving that integrates cognitive biases and distance-based and environmental rewards under a temporal-difference learning mechanism. The model is tested against experimental data obtained ... Keywords: Cognitive biases, Computational modeling, Distance-reduction heuristic, Problem solving, Reinforcement learning, Temporal-difference learning

Frédéric Dandurand; Thomas R. Shultz; Arnaud Rey

2012-01-01T23:59:59.000Z

143

A Distributed Active Information Model Enabling Distributed Autonomics in Complex Electronic Enviornments  

Science Conference Proceedings (OSTI)

Information modeling plays a central role in managing complexity of the distributed electronic systems. This paper proposes a nature-inspired distributed active information model (DAIM) to enable the local decision-making process, that will fundamentally ... Keywords: Distributed Information Model, Object-oriented, XML

Robin Braun; Frank Chiang

2008-11-01T23:59:59.000Z

144

Model-Driven Engineering of Complex Embedded Systems: Concepts and Tools  

E-Print Network (OSTI)

Model-Driven Engineering of Complex Embedded Systems: Concepts and Tools Fl´avio Rech Wagner- neering methods till Model-Driven Engineering (MDE). Then, it introduces the basic principles of MDE Architecture), Software Factories, and MIC (Model Integrated Computing), are explained, and we provide a short

Wagner, Flávio Rech

145

Model Catalysts: Simulating the Complexities of Heterogeneous Catalysts  

Science Conference Proceedings (OSTI)

Surface-science investigations have contributed significantly to heterogeneous catalysis in the past several decades. Fundamental studies of reactive systems on metal single crystals have aided researchers in understanding the effect of surface structure on catalyst reactivity and selectivity for a number of important reactions. Recently, model systems, consisting of metal clusters deposited on planar oxide surfaces, have facilitated the study of metal particle-size and support effects. These model systems not only are useful for carrying out kinetic investigations, but are also amenable to surface spectroscopic techniques, thus enabling investigations under realistic pressures and at working temperatures. By combining surface-science characterization methods with kinetic measurements under realistic working conditions, researchers are continuing to advance the molecular-level understanding of heterogeneous catalysis and are narrowing he pressure and material gap between model and real-world catalysts.

Gao, Feng; Goodman, D. W.

2012-05-01T23:59:59.000Z

146

CTDMPLUS: A Dispersion Model for Sources near Complex Topography. Part II: Performance Characteristics  

Science Conference Proceedings (OSTI)

The Complex Terrain Dispersion Model (CTDMPLUS), described in Part I of this paper, was evaluated using the SO2 field-study data from the Lovett generating station in southeastern New York state. For perspective, CTDMPLUS estimates were also ...

James O. Paumier; Donna J. Burns; Steven G. Perry

1992-07-01T23:59:59.000Z

147

Transferability of a Three-Dimensional Air Quality Model between Two Different Sites in Complex Terrain  

Science Conference Proceedings (OSTI)

The three-dimensional, diagnostic, particle-in-cell transport and diffusion model MATHEW/ADPIC is used to test its transferability from one site in complex terrain to another with different characteristics, under stable nighttime drainage flow ...

Rolf Lange

1989-07-01T23:59:59.000Z

148

On the Ability of the WRF Model to Reproduce the Surface Wind Direction over Complex Terrain  

Science Conference Proceedings (OSTI)

The ability of the Weather Research and Forecasting (WRF) model to reproduce the surface wind direction over complex terrain is examined. A simulation spanning a winter season at a high horizontal resolution of 2 km is compared with wind direction ...

Pedro A. Jiménez; Jimy Dudhia

2013-07-01T23:59:59.000Z

149

Mesoscale Modeling and Four-Dimensional Data Assimilation in Areas of Highly Complex Terrain  

Science Conference Proceedings (OSTI)

A multiscale four-dimensional data assimilation (FDDA) technique, based on Newtonian relaxation, is incorporated into a mesoscale model and evaluated using meteorological and tracer data collected during the Atmospheric Studies in Complex Terrain ...

J. D. Fast

1995-12-01T23:59:59.000Z

150

The Principles of Laboratory Modeling of Stratified Atmospheric Flows over Complex Terrain  

Science Conference Proceedings (OSTI)

Laboratory modeling provides a reasonably quick and relatively inexpensive method for investigating stratified air Row around mesoscale topography. Quantitative results for stratified flow over complex terrain may be obtained from suitably ...

Peter G. Baines; Peter C. Manins

1989-11-01T23:59:59.000Z

151

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

E-Print Network (OSTI)

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 ...

Goosse, H.

152

Complexity of Snow Schemes in a Climate Model and Its Impact on Surface Energy and Hydrology  

Science Conference Proceedings (OSTI)

Three different complexity snow schemes implemented in the ECMWF land surface scheme Hydrology Tiled ECMWF Scheme of Surface Exchanges over Land (HTESSEL) are evaluated within the EC-EARTH climate model. The snow schemes are (i) the original ...

Emanuel Dutra; Pedro Viterbo; Pedro M. A. Miranda; Gianpaolo Balsamo

2012-04-01T23:59:59.000Z

153

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

Science Conference Proceedings (OSTI)

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.

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

154

Structuring of Large-scale Complex Hybrid Systems: from Illustrative Analysis toward Modelization  

Science Conference Proceedings (OSTI)

System structuring is paramount to the development of large-scale complex hybrid systems (LCHS). However, there is no well-established and effective methodology for the structuring of LCHS. Using the approach of illustrating and abstracting, this paper ... Keywords: autonomous system, block-diagram-based model, distributed system, hierarchical system, large-scale complex hybrid system (LCHS), multiple gradation, nested system, nesting, perception–decision link, system geometry, system modelization, system structuring

Huaglory Tianfield

2001-02-01T23:59:59.000Z

155

The Climatological Skill of a Regional Model over Complex Terrain  

Science Conference Proceedings (OSTI)

As part of an ongoing study of the regional climate and hydrology of the southwestern United States, in this paper we investigate the systematic biases of two versions of the PSU/NCAR mesoscale model (MM4). These are a standard version and one ...

Filippo Giorgi; Gary T. Bates

1989-11-01T23:59:59.000Z

156

8, 1175511819, 2008 mixed-phase Arctic  

E-Print Network (OSTI)

, process of ice phase initiation due to freezing of25 supercooled water in both saturatedACPD 8, 11755­11819, 2008 Simulating mixed-phase Arctic stratus clouds I. Sednev et al. Title Page.0 License. Atmospheric Chemistry and Physics Discussions Simulating mixed-phase Arctic stratus clouds

Paris-Sud XI, Université de

157

Wind-Driven Variability of the Large-Scale Recirculating Flow in the Nordic Seas and Arctic Ocean  

Science Conference Proceedings (OSTI)

The varying depth-integrated currents in the Nordic seas and Arctic Ocean are modeled using an integral equation derived from the shallow-water equations. This equation assumes that mass divergence in the surface Ekman layer is balanced by ...

Pål E. Isachsen; J. H. LaCasce; C. Mauritzen; S. Häkkinen

2003-12-01T23:59:59.000Z

158

Vegetation and Topographic Control of Wind-Blown Snow Distributions in Distributed and Aggregated Simulations for an Arctic Tundra Basin  

Science Conference Proceedings (OSTI)

A finescale model of blowing snow is used to simulate the characteristics of snow cover in a low-Arctic catchment with moderate topography and partial shrub cover. The influence of changing shrub characteristics is investigated by performing a ...

Richard Essery; John Pomeroy

2004-10-01T23:59:59.000Z

159

Interdecadal Connection between Arctic Temperature and Summer Precipitation over the Yangtze River Valley in the CMIP5 Historical Simulations  

Science Conference Proceedings (OSTI)

This study assesses the ability of the Phase 5 Coupled Model Intercomparison Project (CMIP5) simulations in capturing the interdecadal precipitation enhancement over the Yangtze River valley (YRV) and investigates the contributions of Arctic ...

Yuefeng Li; L. Ruby Leung; Ziniu Xiao; Min Wei; Qingquan Li

160

A Numerical Study of Sea Ice and Ocean Circulation in the Arctic  

Science Conference Proceedings (OSTI)

A sea-ice model based bulk-viscous plastic dynamics and 3-layer thermodynamics is coupled to a multilevel primitive equation model of the Arctic Ocean and Greenland Sea. The combined model is forced by inflow through the Faeroe-Shetland Channel ...

Albert J. Semtner Jr.

1987-08-01T23:59:59.000Z

Note: This page contains sample records for the topic "modeling complex arctic" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


161

Putting the organization back into computational organization theory: a complex Perrowian model of organizational action  

Science Conference Proceedings (OSTI)

At best, computational models that study organizations incorporate only one perspective of how organizations are known to act within their environments. Such single-perspective models are limited in their generalizability and applicability to the real ... Keywords: Agent-based simulation, Computational organization theory, Organization theory, Organizational complexity

Brian W. Kulik; Timothy Baker

2008-06-01T23:59:59.000Z

162

Multiple Equilibria of the Hadley Circulation in an Intermediate-Complexity Axisymmetric Model  

Science Conference Proceedings (OSTI)

A model of intermediate complexity based on quasi-equilibrium theory—a version of the Quasi-Equilibrium Tropical Circulation Model with a prognostic atmospheric boundary layer, as well as two free-tropospheric modes in momentum, and one each in ...

Gilles Bellon; Adam H. Sobel

2010-04-01T23:59:59.000Z

163

A Model for Objective Simulation of Boundary-Layer Winds in an Area of Complex Terrain  

Science Conference Proceedings (OSTI)

An objective analysis model is formulated to simulate the boundary-layer wind field in an area of complex terrain on the island of Oahu, Hawaii. The model is designed to reproduce the effects of the terrain on the undisturbed trade wind flow in ...

D. André Erasmus

1986-12-01T23:59:59.000Z

164

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

E-Print Network (OSTI)

Modeling Complex Control Systems to Identify Remotely Accessible Devices Vulnerable to Cyber Attack Acquisition (SCADA) systems that allows us to calculate device vulnerability and help power substation vulnerable to cyber attack. We use graph theory to model electric power control and protection devices

Krings, Axel W.

165

Evaluation of Arctic Broadband Surface Radiation Measurements  

Science Conference Proceedings (OSTI)

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.

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

166

Arctic Sea Ice Retreat in 2007 Follows Thinning Trend  

E-Print Network (OSTI)

The minimum of Arctic sea ice extent in the summer of 2007 was unprecedented in the historical record. A coupled ice–ocean model is used to determine the state of the ice and ocean over the past 29 yr to investigate the causes of this ice extent minimum within a historical perspective. It is found that even though the 2007 ice extent was strongly anomalous, the loss in total ice mass was not. Rather, the 2007 ice mass loss is largely consistent with a steady decrease in ice thickness that began in 1987. Since then, the simulated mean September ice thickness within the Arctic Ocean has declined from 3.7 to 2.6 m at a rate of ?0.57 m decade ?1. Both the area coverage of thin ice at the beginning of the melt season and the total volume of ice lost in the summer have been steadily increasing. The combined impact of these two trends caused a large reduction in the September mean ice concentration in the Arctic Ocean. This created conditions during the summer of 2007 that allowed persistent winds to push the remaining ice from the Pacific side to the Atlantic side of the basin and more than usual into the Greenland Sea. This exposed large areas of open water, resulting in the record ice extent anomaly. 1.

R. W. Lindsay; J. Zhang; A. Schweiger; M. Steele; H. Stern

2008-01-01T23:59:59.000Z

167

Radiative Impacts on the Growth of a Population of Drops within Simulated Summertime Arctic Stratus  

Science Conference Proceedings (OSTI)

The impact of solar heating and infrared cooling on the growth of a population of drops is studied with two numerical modeling frameworks. An eddy-resolving model (ERM) simulation of Arctic stratus clouds is used to generate a dataset of 500 ...

Jerry Y. Harrington; Graham Feingold; William R. Cotton

2000-03-01T23:59:59.000Z

168

Low-Frequency Variability in the Arctic Atmosphere, Sea Ice, and Upper-Ocean Climate System  

Science Conference Proceedings (OSTI)

The low-frequency natural variability of the arctic climate system is modeled using a single-column, energy balance model of the atmosphere. sea ice, and upper-ocean system. Variability in the system is induced by forcing with realistic, random ...

C. M. Bitz; D. S. Battisti; R. E. Moritz; J. A. Beesley

1996-02-01T23:59:59.000Z

169

Simulated Arctic Ocean Freshwater Budgets in the Twentieth and Twenty-First Centuries  

Science Conference Proceedings (OSTI)

The Arctic Ocean freshwater budgets in climate model integrations of the twentieth and twenty-first century are examined. An ensemble of six members of the Community Climate System Model version 3 (CCSM3) is used for the analysis, allowing the ...

Marika M. Holland; Joel Finnis; Mark C. Serreze

2006-12-01T23:59:59.000Z

170

Fractional models for modeling complex linear systems under poor frequency resolution measurements  

Science Conference Proceedings (OSTI)

When modeling a linear system in a parametric way, one needs to deal with (i) model structure selection, (ii) model order selection as well as (iii) an accurate fit of the model. The most popular model structure for linear systems has a rational form ... Keywords: Continuous-time modeling, Fractional order systems, Linear systems, Non-asymptotic, Nonlinear least squares, Parametric models, Poor frequency resolutions, Statistical signal processing, Transfer function

Kurt Barbé, Oscar J. Olarte Rodriguez, Wendy Van Moer, Lieve Lauwers

2013-07-01T23:59:59.000Z

171

Storm Studies in the Arctic (STAR)  

Science Conference Proceedings (OSTI)

The Storm Studies in the Arctic (STAR) network (2007–2010) conducted a major meteorological field project from 10 October–30 November 2007 and in February 2008, focused on southern Baffin Island, Nunavut, Canada—a region that experiences intense ...

John Hanesiak; Ronald Stewart; David Barber; George Liu; Justin Gilligan; Danielle Desjardins; Robyn Dyck; Shannon Fargey; Klaus Hochheim; Rebekah Martin; Peter Taylor; Sumita Biswas; Mark Gordon; Marna Albarran Melzer; Kent Moore; Robert Field; Carling Hay; Shunli Zhang; Gordon McBean; Walter Strapp; David Hudak; John Scott; Mengistu Wolde; Ron Goodson; Edward Hudson; Gabrielle Gascon; Heather Greene; William Henson; Alex Laplante

2010-01-01T23:59:59.000Z

172

The Mixed-Phase Arctic Cloud Experiment  

Science Conference Proceedings (OSTI)

The Mixed-Phase Arctic Cloud Experiment (M-PACE) was conducted from 27 September through 22 October 2004 over the Department of Energy's Atmospheric Radiation Measurement (ARM) Climate Research Facility (ACRF) on the North Slope of Alaska. The ...

J. Verlinde; J. Y. Harrington; V. T. Yannuzzi; A. Avramov; S. Greenberg; S. J. Richardson; C. P. Bahrmann; G. M. McFarquhar; G. Zhang; N. Johnson; M. R. Poellot; J. H. Mather; D. D. Turner; E. W. Eloranta; D. C. Tobin; R. Holz; B. D. Zak; M. D. Ivey; A. J. Prenni; P. J. DeMott; J. S. Daniel; G. L. Kok; K. Sassen; D. Spangenberg; P. Minnis; T. P. Tooman; M. Shupe; A. J. Heymsfield; R. Schofield

2007-02-01T23:59:59.000Z

173

A Comparison Between Modeled and Measured Clear-Sky Radiative Shortwave Fluxes in Arctic Environments, with Special Emphasis on Diffuse Radiation  

SciTech Connect

The ability of the SBDART radiative transfer model to predict clear-sky diffuse and direct normal broadband shortwave irradiances is investigated. Model calculations of these quantities are compared with data from the Atmospheric Radiation Measurement (ARM) program’s Southern Great Plains (SGP) and North Slope of Alaska (NSA) sites. The model tends to consistently underestimate the direct normal irradiances at both sites by about 1%. In regards to clear-sky diffuse irradiance, the model overestimates this quantity at the SGP site in a manner similar to what has been observed in other studies (Halthore and Schwartz, 2000). The difference between the diffuse SBDART calculations and Halthore and Schwartz’s MODTRAN calculations is very small, thus demonstrating that SBDART performs similarly to MODTRAN. SBDART is then applied to the NSA site, and here it is found that the discrepancy between the model calculations and corrected diffuse measurements (corrected for daytime offsets, Dutton et al., 2001) is 0.4 W/m2 when averaged over the 12 cases considered here. Two cases of diffuse measurements from a shaded “black and white” pyranometer are also compared with the calculations and the discrepancy is again minimal. Thus, it appears as if the “diffuse discrepancy” that exists at the SGP site does not exist at the NSA sites. We cannot yet explain why the model predicts diffuse radiation well at one site but not at the other.

Barnard, James C.; Flynn, Donna M.

2002-10-08T23:59:59.000Z

174

A Context Model and Reasoning System to improve object trackingin complex scenarios  

Science Conference Proceedings (OSTI)

Tracking algorithms in computer vision usually fail when dealing with complex scenarios. This paper presents an extension of a general tracking system that uses context knowledge to solve tracking issues. The context layer represents knowledge about ... Keywords: Context based reasoning, Knowledge modeling, Video processing, Visual tracking

A. M. Sánchez; M. A. Patricio; J. García; J. M. Molina

2009-10-01T23:59:59.000Z

175

Mechanics of complex bodies: commentary on the unified modelling of material substructures  

E-Print Network (OSTI)

Basic issues of the general model-building framework of the mechanics of complex bodies are discussed. Attention is focused on the representation of the material elements, the conditions for the existence of ground states in conservative setting and the interpretation of the nature of the various balance laws occurring.

Paolo Maria Mariano

2008-03-26T23:59:59.000Z

176

Modeling complex wells with the multi-scale finite-volume method  

Science Conference Proceedings (OSTI)

In this paper, an extension of the multi-scale finite-volume (MSFV) method is devised, which allows to simulate flow and transport in reservoirs with complex well configurations. The new framework fits nicely into the data structure of the original MSFV ... Keywords: Gravity, Heterogeneous media, Multi-phase flow, Multi-scale finite-volume, Porous media, Well modeling

Patrick Jenny; Ivan Lunati

2009-02-01T23:59:59.000Z

177

Speciation model selection by Monte Carlo analysis of optical absorption spectra: Plutonium(IV) nitrate complexes  

Science Conference Proceedings (OSTI)

Standard modeling approaches can produce the most likely values of the formation constants of metal-ligand complexes if a particular set of species containing the metal ion is known or assumed to exist in solution equilibrium with complexing ligands. Identifying the most likely set of species when more than one set is plausible is a more difficult problem to address quantitatively. A Monte Carlo method of data analysis is described that measures the relative abilities of different speciation models to fit optical spectra of open-shell actinide ions. The best model(s) can be identified from among a larger group of models initially judged to be plausible. The method is demonstrated by analyzing the absorption spectra of aqueous Pu(IV) titrated with nitrate ion at constant 2 molal ionic strength in aqueous perchloric acid. The best speciation model supported by the data is shown to include three Pu(IV) species with nitrate coordination numbers 0, 1, and 2. Formation constants are {beta}{sub 1}=3.2{+-}0.5 and {beta}{sub 2}=11.2{+-}1.2, where the uncertainties are 95% confidence limits estimated by propagating raw data uncertainties using Monte Carlo methods. Principal component analysis independently indicates three Pu(IV) complexes in equilibrium. (c) 2000 Society for Applied Spectroscopy.

Berg, John M. [Nuclear Materials Technology Division, Los Alamos National Laboratory, Los Alamos, New Mexico 87545 (United States); Veirs, D. Kirk [Nuclear Materials Technology Division, Los Alamos National Laboratory, Los Alamos, New Mexico 87545 (United States); Vaughn, Randolph B. [Nuclear Materials Technology Division, Los Alamos National Laboratory, Los Alamos, New Mexico 87545 (United States); Cisneros, Michael R. [Nuclear Materials Technology Division, Los Alamos National Laboratory, Los Alamos, New Mexico 87545 (United States); Smith, Coleman A. [Nuclear Materials Technology Division, Los Alamos National Laboratory, Los Alamos, New Mexico 87545 (United States)

2000-06-01T23:59:59.000Z

178

ORNL DAAC, Arctic Tundra Flux Data, February 2002  

NLE Websites -- All DOE Office Websites (Extended Search)

atmospheric fluxes in the Arctic tundra are now available on-line. The newly released data set "Arctic Tundra Flux Study in the Kuparuk River Basin (Alaska), 1994-1996" contains...

179

Is A Sleeping Climate Giant Stirring in the Arctic?  

NLE Websites -- All DOE Office Websites (Extended Search)

Is A Sleeping Climate Giant Stirring in the Arctic? Print E-mail Is a sleeping climate giant stirring in the arctic? Wednesday, June 12, 2013 Featured by NASA a member of the U.S....

180

Arctic Climate Change as Manifest in Cyclone Behavior  

Science Conference Proceedings (OSTI)

The Arctic region has exhibited dramatic changes in recent times. Many of these are intimately tied up with synoptic activity, but little research has been undertaken on how the characteristics of Arctic cyclones have changed. This paper presents ...

Ian Simmonds; Craig Burke; Kevin Keay

2008-11-01T23:59:59.000Z

Note: This page contains sample records for the topic "modeling complex arctic" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


181

Comments on “Current GCMs' Unrealistic Negative Feedback in the Arctic”  

Science Conference Proceedings (OSTI)

In contrast to prior studies showing a positive lapse-rate feedback associated with the Arctic inversion, Boé et al. reported that strong present-day Arctic temperature inversions are associated with stronger negative longwave feedbacks and thus ...

Felix Pithan; Thorsten Mauritsen

2013-10-01T23:59:59.000Z

182

Dynamical and Microphysical Characteristics of Arctic Clouds during BASE  

Science Conference Proceedings (OSTI)

In this study, observations from aircraft, Doppler radar, and LANDSAT are used to better understand dynamical and microphysical characteristics of low-level Arctic clouds for climate change studies. Observations during the Beaufort and Arctic ...

I. Gultepe; G. Isaac; D. Hudak; R. Nissen; J. W. Strapp

2000-04-01T23:59:59.000Z

183

Comments on “Current GCMs’ Unrealistic Negative Feedback in the Arctic”  

Science Conference Proceedings (OSTI)

Contrasting our expectation of a positive lapse-rate feedback associated with the Arctic inversion, Boé et al. (2009) report that strong present-day Arctic temperature inversions are associated with stronger negative longwave feedbacks and thus ...

Felix Pithan; Thorsten Mauritsen

184

Vertical Motions in Arctic Mixed-Phase Stratiform Clouds  

Science Conference Proceedings (OSTI)

The characteristics of Arctic mixed-phase stratiform clouds and their relation to vertical air motions are examined using ground-based observations during the Mixed-Phase Arctic Cloud Experiment (MPACE) in Barrow, Alaska, during fall 2004. The ...

Matthew D. Shupe; Pavlos Kollias; P. Ola G. Persson; Greg M. McFarquhar

2008-04-01T23:59:59.000Z

185

Tuktoyaktuk : responsive strategies for a new Arctic urbanism  

E-Print Network (OSTI)

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 ...

Ritchot, Pamela (Pamela Rae)

2011-01-01T23:59:59.000Z

186

The Western Arctic Linkage Experiment (WALE): Overview and Synthesis  

Science Conference Proceedings (OSTI)

The primary goal of the Western Arctic Linkage Experiment (WALE) was to better understand uncertainties of simulated hydrologic and ecosystem dynamics of the western Arctic in the context of 1) uncertainties in the data available to drive the ...

A. D. McGuire; J. E. Walsh; J. S. Kimball; J. S. Clein; S. E. Euskirchen; S. Drobot; U. C. Herzfeld; J. Maslanik; R. B. Lammers; M. A. Rawlins; C. J. Vorosmarty; T. S. Rupp; W. Wu; M. Calef

2008-06-01T23:59:59.000Z

187

The Arctic Ocean Response to the North Atlantic Oscillation  

Science Conference Proceedings (OSTI)

The climatically sensitive zone of the Arctic Ocean lies squarely within the domain of the North Atlantic oscillation (NAO), one of the most robust recurrent modes of atmospheric behavior. However, the specific response of the Arctic to annual ...

R. R. Dickson; T. J. Osborn; J. W. Hurrell; J. Meincke; J. Blindheim; B. Adlandsvik; T. Vinje; G. Alekseev; W. Maslowski

2000-08-01T23:59:59.000Z

188

Position paper for UCSB workshop “Agent-based modeling of complex spatial systems”  

E-Print Network (OSTI)

Early successful examples of spatial agent-based models were often highly abstract, and were used to demonstrate how particular macro-scale outcomes could emerge as the result of decentralized interactions of autonomous decision-making agents. Examples include the demonstration of segregation provided by Schelling’s early models (Schelling 1971) and the emergence of power-law distributions of wealth from Epstein and Axtell’s Sugarscape model (Epstein and Axtell 1996). Such models had a very simple role: to extend theory by demonstrating that a particular set of behaviors and interactions could generate a particular macro-scale or emergent outcome (Epstein 1999). As the discipline of spatial-agent based modeling matures, an increasing number of highly empirical models (in the style of “Cell 4 ” models as described by Parker, Berger, and Manson (2002) are being constructed. These models are often developed to support policy analysis, and are motivated by a belief that models that include complex dynamics and interactions are likely to produce “better ” results that models that omit those dynamics. While my discussion focuses on models of human-environment interactions (Bousquet

Dawn Parker

2007-01-01T23:59:59.000Z

189

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

SciTech Connect

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.

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

2008-11-01T23:59:59.000Z

190

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

Science Conference Proceedings (OSTI)

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

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

2010-09-01T23:59:59.000Z

191

Normal matrix models, dbar-problem, and orthogonal polynomials on the complex plane  

E-Print Network (OSTI)

We introduce a dbar-formulation of the orthogonal polynomials on the complex plane, and hence of the related normal matrix model, which is expected to play the same role as the Riemann-Hilbert formalism in the theory of orthogonal polynomials on the line and for the related Hermitian model. We propose an analog of Deift-Kriecherbauer-McLaughlin-Venakides-Zhou asymptotic method for the analysis of the relevant dbar-problem, and indicate how familiar steps for the Hermitian model, e.g. the g-function ``undressing'', might look like in the case of the normal model. We use the particular model considered recently by P. Elbau and G. Felder as a case study.

Alexander R. Its; Leon A. Takhtajan

2007-08-28T23:59:59.000Z

192

Real-time modeling of complex atmospheric releases in urban areas  

Science Conference Proceedings (OSTI)

If a nuclear installation in or near an urban area has a venting, fire, or explosion, airborne radioactivity becomes the major concern. Dispersion models are the immediate tool for estimating the dose and contamination. Responses in urban areas depend on knowledge of the amount of the release, representative meteorological data, and the ability of the dispersion model to simulate the complex flows as modified by terrain or local wind conditions. A centralized dispersion modeling system can produce realistic assessments of radiological accidents anywhere in a country within several minutes if it is computer-automated. The system requires source-term, terrain, mapping and dose-factor databases, real-time meteorological data acquisition, three-dimensional atmospheric transport and dispersion models, and experienced staff. Experience with past responses in urban areas by the Atmospheric Release Advisory Capability (ARAC) program at Lawrence Livermore National Laboratory illustrate the challenges for three-dimensional dispersion models.

Baskett, R.L. [EG and G Energy Measurements, Inc., Pleasanton, CA (United States); Ellis, J.S.; Sullivan, T.J. [Lawrence Livermore National Lab., CA (United States)

1994-08-01T23:59:59.000Z

193

Sensitivity of Arctic Climate Variability to Mean State: Insights from the Cretaceous  

Science Conference Proceedings (OSTI)

This study investigates Arctic climate variability during a period of extreme warmth using the CCSM3 coupled ocean-atmosphere general circulation model. Four mid-Cretaceous simulations were completed with different CO2 levels (1x, 10x, and 16x pre-...

Christopher J. Poulsen; Jing Zhou

194

Late-Twentieth-Century Simulation of Arctic Sea Ice and Ocean Properties in the CCSM4  

Science Conference Proceedings (OSTI)

To establish how well the new Community Climate System Model, version 4 (CCSM4) simulates the properties of the Arctic sea ice and ocean, results from six CCSM4 twentieth-century ensemble simulations are compared here with the available data. It ...

Alexandra Jahn; Kara Sterling; Marika M. Holland; Jennifer E. Kay; James A. Maslanik; Cecilia M. Bitz; David A. Bailey; Julienne Stroeve; Elizabeth C. Hunke; William H. Lipscomb; Daniel A. Pollak

2012-03-01T23:59:59.000Z

195

The ocean's role in polar climate change: asymmetric Arctic and Antarctic responses to greenhouse gas and  

E-Print Network (OSTI)

by order 12% per decade, with smaller reductions in winter. Coupled models suggest that under greenhouse-gasThe ocean's role in polar climate change: asymmetric Arctic and Antarctic responses to greenhouse gas and ozone forcing John Marshall, Kyle Armour, Jeffery Scott and Yavor Kostov (MIT) David Ferreira

Wirosoetisno, Djoko

196

Impact of variable atmospheric and oceanic form drag on simulations of Arctic sea ice  

Science Conference Proceedings (OSTI)

Over Arctic sea ice, pressure ridges, floe and melt pond edges all introduce discrete obstructions to the flow of air or water past the ice, and are a source of form drag. In current climate models form drag is only accounted for by tuning the air-...

Michel Tsamados; Daniel L. Feltham; David Schroeder; Daniela Flocco; Sinead L. Farrell; Nathan Kurtz; Seymour W. Laxon; Sheldon Bacon

197

Agent-based and macroscopic modeling of the complex socio-economic systems  

E-Print Network (OSTI)

The current economic crisis has provoked an active response from the interdisciplinary scientific community. As a result many papers suggesting what can be improved in understanding of the complex socio-economics systems were published. Some of the most prominent papers on the topic include (Bouchaud, 2009; Farmer and Foley, 2009; Farmer et al, 2012; Helbing, 2010; Pietronero, 2008). These papers share the idea that agent-based modeling is essential for the better understanding of the complex socio-economic systems and consequently better policy making. Yet in order for an agent-based model to be useful it should also be analytically tractable, possess a macroscopic treatment (Cristelli et al, 2012). In this work we shed a new light on our research group's contributions towards understanding of the correspondence between the inter-individual interactions and collective behavior. We also provide some new insights into the implications of the global and local interactions, the leadership and the predator-prey i...

Kononovicius, Aleksejus

2013-01-01T23:59:59.000Z

198

Status of Wind-Diesel Applications in Arctic Climates: Preprint  

DOE Green Energy (OSTI)

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.

Baring-Gould, I.; Corbus, D.

2007-12-01T23:59:59.000Z

199

The 1990 Valentine's Day Arctic Outbreak. Part I: Mesoscale and Microscale Structure and Evolution of a Colorado Front Range Shallow Upslope Cloud  

Science Conference Proceedings (OSTI)

The mesoscale and microscale structure and evolution of a shallow, upslope cloud is described using observations obtained during the Winter Icing and Storms Project (WISP) and model stimulations. The upslope cloud formed within a shallow arctic ...

Roy M. Rasmussen; Ben C. Bernstein; Masataka Murakami; Greg Stossmeister; Jon Reisner; Boba Stankov

1995-07-01T23:59:59.000Z

200

Response of the Wintertime Northern Hemisphere Atmospheric Circulation to Current and Projected Arctic Sea Ice Decline: A Numerical Study with CAM5  

Science Conference Proceedings (OSTI)

The wintertime Northern Hemisphere (NH) atmospheric circulation response to current (2007–12) and projected (2080–99) Arctic sea ice decline is examined with the latest version of the Community Atmospheric Model (CAM5). The numerical experiments ...

Yannick Peings; Gudrun Magnusdottir

2014-01-01T23:59:59.000Z

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201

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

DOE Green Energy (OSTI)

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.

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

2012-04-01T23:59:59.000Z

202

Modeling the electricity market as a complex adaptive system with an agent-based approach.  

SciTech Connect

As power markets are relatively new and still continue to evolve, there is a growing need for advanced modeling approaches that simulate the behavior of electricity markets over time and how market participants may act and react to the changing economic, financial and regulatory environments in which they operate. A new and rather promising approach is to model the electricity market as a complex adaptive system using an agent-based modeling and simulation (ABMS) approach. The purpose of an ABMS model is not necessarily to predict the outcome of a system but to reveal and understand the complex and aggregate system behaviors that emerge from the interactions of the heterogeneous individual entities. Emergent behavior is a key feature of ABMS and is not easily inferred from the simple sum of the behavior of its components. By relying on both established engineering modeling techniques as well as advanced quantitative economic market principles, the ABMS approach is uniquely suited to addressing the strategic issues of interest to different market participants as well as those of market monitors and regulators.

Koritarov, V.; Decision and Information Sciences

2004-07-01T23:59:59.000Z

203

ISDAC Modeling  

NLE Websites -- All DOE Office Websites (Extended Search)

Modeling Modeling Modeling of aerosol effects on Arctic stratiform clouds: Preliminary results from the ISDAC case study (poster 13J) Mikhail Ovchinnikov, Steve Ghan, Jiwen Fan, Xiaohong Liu (PNNL), Alexei Korolev, Peter Liu (Env. Canada) Shaocheng Xie (LLNL), Hugh Morrison (NCAR), ISDAC PI's, and members of the CMWG 2 Indirect Semi-Direct Aerosol Campaign Science questions: How do properties of the arctic aerosol during April differ from those measured during the MPACE in October? To what extent do the different properties of the arctic aerosol during April produce differences in the microphysical and macrophysical properties of clouds and the surface energy balance? To what extent can cloud models and the cloud parameterizations used in climate models simulate the sensitivity of arctic clouds and

204

Arctic Methane, Hydrates, and Global Climate  

NLE Websites -- All DOE Office Websites (Extended Search)

Arctic Methane, Hydrates, and Global Climate Arctic Methane, Hydrates, and Global Climate Speaker(s): Matthew T. Reagan Date: March 17, 2010 - 12:00pm Location: 90-3122 Paleooceanographic evidence has been used to postulate that methane may have had a significant role in regulating past climate. However, the behavior of contemporary permafrost deposits and oceanic methane hydrate deposits subjected to rapid temperature changes, like those now occurring in the arctic and those predicted under future climate change scenarios, has only recently been investigated. A recent expedition to the west coast of Spitsbergen discovered substantial methane gas plumes exiting the seafloor at depths that correspond to the upper limit of the receding gas hydrate stability zone. It has been suggested that these plumes may be the

205

Diagnostic Wind Field Modeling for Complex Terrain: Model Development and Testing  

Science Conference Proceedings (OSTI)

A three dimensional diagnostic wind field model is shown to be capable of generating potential flow solutions associated with simple terrain features. This is achieved by modifying an initially uniform background wind to make the flow divergence ...

D. G. Ross; I. N. Smith; P. C. Manins; D. G. Fox

1988-07-01T23:59:59.000Z

206

A unified fuzzy model-based framework for modeling and control of complex systems: from flying vehicle control to brain-machine cooperative control  

Science Conference Proceedings (OSTI)

The invited lecture in 2012 IEEE World Congress on Computational Intelligence (WCCI 2012) presents an overview of a unified fuzzy model-based framework for modeling and control of complex systems. A number of practical applications, ranging from flying ...

Kazuo Tanaka

2012-06-01T23:59:59.000Z

207

A ‘‘string of feature graphs’’ model for recognition of complex activities  

E-Print Network (OSTI)

Videos usually consist of activities involving interactions between multiple actors, sometimes referred to as complex activities. Recognition of such activities requires modeling the spatio-temporal relationships between the actors and their individual variabilities. In this paper, we consider the problem of recognition of complex activities in a video given a query example. We propose a new feature model based on a string representation of the video which respects the spatio-temporal ordering. This ordered arrangement of local collections of features (e.g., cuboids, STIP), which are the characters in the string, are initially matched using graph-based spectral techniques. Final recognition is obtained by matching the string representations of the query and the test videos in a dynamic programming framework which allows for variability in sampling rates and speed of activity execution. The method does not require tracking or recognition of body parts, is able to identify the region of interest in a cluttered scene, and gives reasonable performance with even a single query example. We test our approach in an example-based video retrieval framework with two publicly available complex activity datasets and provide comparisons against other methods that have studied this problem. 1.

U. Gaur; Y. Zhu; B. Song; A. Roy-chowdhury

2011-01-01T23:59:59.000Z

208

The Arctic and Subarctic Ocean Flux of Potential Vorticity and the Arctic Ocean Circulation  

Science Conference Proceedings (OSTI)

According to observations, the Arctic Ocean circulation beneath a shallow thermocline can be schematized by cyclonic rim currents along shelves and over ridges. In each deep basin, the circulation is also believed to be cyclonic. This circulation ...

Jiayan Yang

2005-12-01T23:59:59.000Z

209

Arctic Energy Technology Development Laboratory  

DOE Green Energy (OSTI)

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.

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

210

Spatiotemporal Climate Model Validation—Case Studies for MM5 over Northwestern Canada and Alaska  

Science Conference Proceedings (OSTI)

The Western Arctic Linkage Experiment (WALE) is aimed at understanding the role of high-latitude terrestrial ecosystems in the response of the Arctic system to global change through collection and comparison of climate datasets and model results. ...

Ute C. Herzfeld; Sheldon Drobot; Wanli Wu; Charles Fowler; James Maslanik

2007-12-01T23:59:59.000Z

211

Development of Exhibit on Arctic Climate Change Called The Arctic: A Friend Acting Strangely Exhibition  

SciTech Connect

The exhibition, The Arctic: A Friend Acting Strangely, was developed at the Smithsonian Institution’s National Museum of Natural History (NMNH) as a part of the museum’s Forces of Change exhibit series on global change. It opened to the public in Spring 2006, in conjunction with another Forces of Change exhibit on the Earth’s atmosphere called Change Is in the Air. The exhibit was a 2000 square-foot presentation that explored the forces and consequences of the changing Arctic as documented by scientists and native residents alike. Native peoples of the Arctic have always lived with year-to-year fluctuations in weather and ice conditions. In recent decades, they have witnessed that the climate has become unpredictable, the land and sea unfamiliar. An elder in Arctic Canada recently described the weather as uggianaqtuq —an Inuit word that can suggest strange, unexpected behavior, sometimes described as that of “a friend acting strangely.” Scientists too have been documenting dramatic changes in the Arctic. Air temperatures have warmed over most—though not all—of the Arctic since the 1950s; Arctic precipitation may have increased by as much as 8%; seasonal melting of the Greenland Ice Sheet has increased on average by 16% since 1979; polar-orbiting satellites have measured a 15¬–20% decline in sea ice extent since the 1970s; aircraft reconnaissance and ship observations show a steady decrease in sea ice since the 1950s. In response to this warming, plant distributions have begun to shift and animals are changing their migration routes. Some of these changes may have beneficial effects while others may bring hardship or have costly implications. And, many scientists consider arctic change to be a ‘bell-weather’ for large-scale changes in other regions of the world. The exhibition included text, photos artifacts, hands-on interactives and other exhibitry that illustrated the changes being documented by indigenous people and scientists alike.

Stauffer, Barbara W.

2006-04-01T23:59:59.000Z

212

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

SciTech Connect

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.

Eric T. DeWeaver

2010-02-17T23:59:59.000Z

213

Review of science issues, deployment strategy, and status for the ARM north slope of Alaska-Adjacent Arctic Ocean climate research site  

SciTech Connect

Recent climate modeling results point to the Arctic as a region that is particularly sensitive to global climate change. The Arctic warming predicted by the models to result from the expected doubling of atmospheric carbon dioxide is two to three times the predicted mean global warming, and considerably greater than the warming predicted for the Antarctic. The North Slope of Alaska-Adjacent Arctic Ocean (NSA-AAO) Cloud and Radiation Testbed (CART) site of the Atmospheric Radiation Measurement (ARM) Program is designed to collect data on temperature-ice-albedo and water vapor-cloud-radiation feedbacks, which are believed to be important to the predicted enhanced warming in the Arctic. The most important scientific issues of Arctic, as well as global, significance to be addressed at the NSA-AAO CART site are discussed, and a brief overview of the current approach toward, and status of, site development is provided. ARM radiometric and remote sensing instrumentation is already deployed and taking data in the perennial Arctic ice pack as part of the SHEBA (Surface Heat Budget of the Arctic ocean) experiment. In parallel with ARM`s participation in SHEBA, the NSA-AAO facility near Barrow was formally dedicated on 1 July 1997 and began routine data collection early in 1998. This schedule permits the US Department of Energy`s ARM Program, NASA`s Arctic Cloud program, and the SHEBA program (funded primarily by the National Science Foundation and the Office of Naval Research) to be mutually supportive. In addition, location of the NSA-AAO Barrow facility on National Oceanic and Atmospheric Administration land immediately adjacent to its Climate Monitoring and Diagnostic Laboratory Barrow Observatory includes NOAA in this major interagency Arctic collaboration.

Stamnes, K. [Univ. of Alaska, Fairbanks, AK (United States). Geophysical Inst.; Ellingson, R.G. [Univ. of Maryland, College Park, MD (United States). Dept. of Meteorology; Curry, J.A. [Univ. of Colorado, Boulder, CO (United States). Dept. of Aerospace and Engineering Sciences; Walsh, J.E. [Univ. of Illinois, Urbana, IL (United States). Dept. of Atmospheric Sciences; Zak, B.D. [Sandia National Labs., Albuquerque, NM (United States)

1999-01-01T23:59:59.000Z

214

Low complexity channel models for approximating flat Rayleigh fading in network simulations  

E-Print Network (OSTI)

The intricate dependency of networking protocols upon the performance of the wireless channel motivates the investigation of network channel approximations for fading channels. Wireless networking protocols are increasingly being designed and evaluated with the assistance of networking simulators. While evaluating networking protocols such as medium access control, routing, and reliable transport, the network channel model, and its associated capacity, will drastically impact the achievable network throughput. Researcher relying upon simulation results must therefore use extreme caution to ensure the use of similar channel models when performing protocol comparisons. Some channel approximations have been created to mimic the behavior of a fading environment, however there exists little to no justification for these channel approximations. This dissertation addresses the need for a computationally efficient fading channel approximation for use in network simulations. A rigorous flat fading channel model was developed for use in accuracy measurements of channel approximations. The popular two-state Markov model channel approximation is analyzed and shown to perform poorly for low to moderate signal-to-noise ratios (SNR). Three novel channel approximations are derived, with multiple methods of parameter estimation. Each model is analyzed for both statistical performance and network performance. The final model is shown to achieve very accurate network throughput performance by achieving a very close matching of the frame run distributions. This work provides a rigorous evaluation of the popular two-state Markov model, and three novel low complexity channel models in both statistical accuracy and network throughput performance. The novel models are formed through attempts to match key statistical parameters of frame error run and good frame run statistics. It is shown that only matching key parameters is insufficient to achieve an acceptable channel approximation and that it is necessary to approximate the distribution of frame error duration and good frame run duration. The final novel channel approximation, the three-state run-length model, is shown to achieve a good approximation of the desired distributions when some key statistical parameters are matched.

McDougall, Jeffrey Michael

2003-08-01T23:59:59.000Z

215

Development of a Composite Non-Electrostatic Surface Complexation Model Describing Plutonium Sorption to Aluminosilicates  

SciTech Connect

Due to their ubiquity in nature and chemical reactivity, aluminosilicate minerals play an important role in retarding actinide subsurface migration. However, very few studies have examined Pu interaction with clay minerals in sufficient detail to produce a credible mechanistic model of its behavior. In this work, Pu(IV) and Pu(V) interactions with silica, gibbsite (Aloxide), and Na-montmorillonite (smectite clay) were examined as a function of time and pH. Sorption of Pu(IV) and Pu(V) to gibbsite and silica increased with pH (4 to 10). The Pu(V) sorption edge shifted to lower pH values over time and approached that of Pu(IV). This behavior is apparently due to surface mediated reduction of Pu(V) to Pu(IV). Surface complexation constants describing Pu(IV)/Pu(V) sorption to aluminol and silanol groups were developed from the silica and gibbsite sorption experiments and applied to the montmorillonite dataset. The model provided an acceptable fit to the montmorillonite sorption data for Pu(V). In order to accurately predict Pu(IV) sorption to montmorillonite, the model required inclusion of ion exchange. The objective of this work is to measure the sorption of Pu(IV) and Pu(V) to silica, gibbsite, and smectite (montmorillonite). Aluminosilicate minerals are ubiquitous at the Nevada National Security Site and improving our understanding of Pu sorption to aluminosilicates (smectite clays in particular) is essential to the accurate prediction of Pu transport rates. These data will improve the mechanistic approach for modeling the hydrologic source term (HST) and provide sorption Kd parameters for use in CAU models. In both alluvium and tuff, aluminosilicates have been found to play a dominant role in the radionuclide retardation because their abundance is typically more than an order of magnitude greater than other potential sorbing minerals such as iron and manganese oxides (e.g. Vaniman et al., 1996). The sorption database used in recent HST models (Carle et al., 2006) and upscaled for use in CAU models (Stoller-Navarro, 2008) includes surface complexation constants for U, Am, Eu, Np and Pu (Zavarin and Bruton, 2004). Generally, between 15 to 30 datasets were used to develop the constants for each radionuclide. However, the constants that describe Pu sorption to aluminosilicates were developed using only 10 datasets, most of which did not specify the oxidation state of Pu in the experiment. Without knowledge or control of the Pu oxidation state, a high degree of uncertainty is introduced into the model. The existing Pu surface complexation model (e.g. Zavarin and Bruton, 2004) drastically underestimates Pu sorption and, thus, will overestimate Pu migration rates (Turner, 1995). Recent HST simulations at Cambric (Carle et al., 2006) suggest that the existing surface complexation model may underpredict Pu K{sub d}s by as much as 3 orders of magnitude. In order to improve HST and CAU-scale transport models (and, as a result, reduce the conservative nature Pu migration estimates), sorption experiments were performed over a range of solution conditions that brackets the groundwater chemistry of the Nevada National Security Site. The aluminosilicates examined were gibbsite, silica, and montmorillonite.

Powell, B A; Kersting, A; Zavarin, M; Zhao, P

2008-10-28T23:59:59.000Z

216

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

SciTech Connect

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.

Eric T. DeWeaver

2010-01-19T23:59:59.000Z

217

Snow Depth on Arctic Sea Ice  

Science Conference Proceedings (OSTI)

Snow depth and density were measured at Soviet drifting stations on multiyear Arctic sea ice. Measurements were made daily at fixed stakes at the weather station and once- or thrice-monthly at 10-m intervals on a line beginning about 500 m from ...

Stephen G. Warren; Ignatius G. Rigor; Norbert Untersteiner; Vladimir F. Radionov; Nikolay N. Bryazgin; Yevgeniy I. Aleksandrov; Roger Colony

1999-06-01T23:59:59.000Z

218

Arctic Sea Ice Albedo from AVHRR  

Science Conference Proceedings (OSTI)

The seasonal cycle of surface albedo of sea ice in the Arctic is estimated from measurements made with the Advanced Very High Resolution Radiometer (AVHRR) on the polar-orbiting satellites NOAA-10 and NOAA-11. The albedos of 145 200-km-square ...

R. W. Lindsay; D. A. Rothrock

1994-11-01T23:59:59.000Z

219

The FGGE Arctic Data Buoy Program  

Science Conference Proceedings (OSTI)

An array of about 20 drifting data buoys was established in the Arctic Ocean during the early months of 1979. The position of each buoy and the surface pressure and temperature are measured several times daily. The program expands our capability ...

A. S. Thorndike

1980-12-01T23:59:59.000Z

220

NOAAINMFS Developments Arctic Marine Research Contracts Awarded  

E-Print Network (OSTI)

on tunal porpoise, and the economic and biolog- August 1977 pacts of gas and oil exploration pre- dict the probable ecological impacts of oil and gas development on Alaska's outer continental mammals, and birds, and smaller organisms which oc- cupy the two Arctic coastal areas prior to oil and gas

Note: This page contains sample records for the topic "modeling complex arctic" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


221

Surface Heat Budget of the Arctic Ocean  

Science Conference Proceedings (OSTI)

A summary is presented of the Surface Heat Budget of the Arctic Ocean (SHEBA) project, with a focus on the field experiment that was conducted from October 1997 to October 1998. The primary objective of the field work was to collectocean, ice, ...

Taneil Uttal; Judith A. Curry; Miles G. Mcphee; Donald K. Perovich; Richard E. Moritz; James A. Maslanik; Peter S. Guest; Harry L. Stern; James A. Moore; Rene Turenne; Andreas Heiberg; Mark C. Serreze; Donald P. Wylie; Ola G. Persson; Clayton A. Paulson; Christopher Halle; James H. Morison; Patricia A. Wheeler; Alexander Makshtas; Harold Welch; Matthew D. Shupe; Janet M. Intrieri; Knut Stamnes; Ronald W. Lindsey; Robert Pinkel; W. Scott Pegau; Timothy P. Stanton; Thomas C. Grenfeld

2002-02-01T23:59:59.000Z

222

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

E-Print Network (OSTI)

Turbulent flows and coherent structures emerging within turbulent flow fields have been extensively studied for the past few decades and a wide variety of experimental and numerical techniques have been developed for measurement and analysis of turbulent flows. The complex nature of turbulence requires methods that can accurately estimate its highly chaotic spatial and temporal behavior. Some of the classical cases of turbulent flows with simpler geometries have been well characterized by means of the existing experimental techniques and numerical models. Nevertheless, since most turbulent fields are of complex geometries; there is an increasing interest in the study of turbulent flows through models with more complicated geometries. In this dissertation, characteristics of turbulent flows through two different facilities with complex geometries are studied applying two different experimental methods. The first study involves the investigation of turbulent impinging jets through a staggered array of rods with or without crossflow. Such flows are crucial in various engineering disciplines. This experiment aimed at modeling the coolant flow behavior and mixing phenomena within the lower plenum of a Very High Temperature Reactor (VHTR). Dynamic Particle Image Velocimetry (PIV) and Matched Index of Refraction (MIR) techniques were applied to acquire the turbulent velocity fields within the model. Some key flow features that may significantly enhance the flow mixing within the test section or actively affect some of the structural components were identified in the velocity fields. The evolution of coherent structures within the flow field is further investigated using a Snapshot Proper Orthogonal Decomposition (POD) technique. Furthermore, a comparative POD method is proposed and successfully implemented for identification of the smaller but highly influential coherent structures which may not be captured in the full-field POD analysis. The second experimental study portrays the coolant flow 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 Anemometry (HWA) system is applied for velocity measurements and investigation of the bypass flow phenomena within the near wall gaps of the core. The velocity profiles within the gaps verify the presence of an area of increased velocity close to the outer reflector wall; however, the characteristics of the coolant flow profile is highly dependent on the gap geometry and to a less extent on the Reynolds number of the flow. The time histories of the velocity are further analyzed using a Power Spectra Density (PSD) technique to acquire information about the energy content and energy transfer between eddies of different sizes at each point within the gaps.

Amini, Noushin

2011-12-01T23:59:59.000Z

223

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

SciTech Connect

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.

Kim, Tae Yun; Khangaonkar, Tarang

2012-05-01T23:59:59.000Z

224

Thermodynamic modeling of neptunium(V)-acetate complexation in concentrated NaCl media  

Science Conference Proceedings (OSTI)

The complexation of neptunium(V), Np(V), with the acetate anion, Ac{sup -}, was measured in sodium chloride media to high concentration using an extraction technique. The data were interpreted using the thermodynamic formalism of Pitzer, which is valid to high electrolyte concentrations. A consistent model for the deprotonation constants of acetic acid in NaCl and NaClO{sub 4} media was developed. For the concentrations of acetate expected in a waste repository, only the neutral complex NpO{sub 2}Ac(aq) was important in describing the interactions between the neptunyl ion and acetate. The thermodynamic stability constant log {beta}{sup 0}{sub 101} for the reaction NpO{sub 2}{sup +} + Ac{sup -} {leftrightarrow} NpO{sub 2}Ac was calculated to be 1.46{plus_minus}0.11. This weak complexing behavior between the neptunyl ion and acetate indicates that acetate will not significantly enhance dissolved Np(V) concentrations in ground waters associated with nuclear waste repositories that may contain acetate.

Novak, C.F.; Borkowski, M.; Choppin, G.R.

1995-09-01T23:59:59.000Z

225

A recent bifurcation in Arctic sea-ice cover  

E-Print Network (OSTI)

There is ongoing debate over whether Arctic sea-ice has already passed a 'tipping point', or whether it will do so in future, with several recent studies arguing that the loss of summer sea ice does not involve a bifurcation because it is highly reversible in models. Recently developed methods can detect and sometimes forewarn of bifurcations in time-series data, hence we applied them to satellite data for Arctic sea-ice cover. Here we show that a new low ice cover state has appeared from 2007 onwards, which is distinct from the normal state of seasonal sea ice variation, suggesting a bifurcation has occurred from one attractor to two. There was no robust early warning signal of critical slowing down prior to this bifurcation, consistent with it representing the appearance of a new ice cover state rather than the loss of stability of the existing state. The new low ice cover state has been sampled predominantly in summer-autumn and seasonal forcing combined with internal climate variability are likely respons...

Livina, Valerie N

2012-01-01T23:59:59.000Z

226

A Comparison of Simple and Complex Treatments of Surface Hydrology and Thermodynamics Suitable for Mesoscale Atmospheric Models  

Science Conference Proceedings (OSTI)

Alternative treatments of the hydrologic and thermodynamic processes at the earth's surface within a mesoscale model are discussed in this study. Specifically, the question of under what circumstances it is necessary to use a complex surface ...

Mercedes N. Lakhtakia; Thomas T. Warner

1994-05-01T23:59:59.000Z

227

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

E-Print Network (OSTI)

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 ...

Alfaris, Anas (Anas Faris)

2009-01-01T23:59:59.000Z

228

An Immersed Boundary Method Enabling Large-Eddy Simulations of Flow over Complex Terrain in the WRF Model  

Science Conference Proceedings (OSTI)

This paper describes a three-dimensional immersed boundary method (IBM) that facilitates the explicit resolution of complex terrain within the Weather Research and Forecasting (WRF) model. Two interpolation methods—trilinear and inverse distance ...

Katherine A. Lundquist; Fotini Katopodes Chow; Julie K. Lundquist

2012-12-01T23:59:59.000Z

229

Modeling Wind Field and Pollution Transport over a Complex Terrain Using an Emergency Dose Information Code SPEEDI  

Science Conference Proceedings (OSTI)

Atmospheric dispersion code system SPEEDI (System for Prediction of Environmental Emergency Dose Information) has been applied to simulate the field experiments conducted over a complex terrain. A diagnostic mass-consistent wind field model of ...

R. Venkatesan; M. Möllmann-Coers; A. Natarajan

1997-09-01T23:59:59.000Z

230

Probing Complex Free-Radical Reaction Pathways of Fuel Model Compounds  

Science Conference Proceedings (OSTI)

Fossil (e.g. coal) and renewable (e.g. woody biomass) organic energy resources have received considerable attention as possible sources of liquid transportation fuels and commodity chemicals. Knowledge of the reactivity of these complex materials has been advanced through fundamental studies of organic compounds that model constituent substructures. In particular, an improved understanding of thermochemical reaction pathways involving free-radical intermediates has arisen from detailed experimental kinetic studies and, more recently, advanced computational investigations. In this presentation, we will discuss our recent investigations of the fundamental pyrolysis pathways of model compounds that represent key substructures in the lignin component of woody biomass with a focus on molecules representative of the dominant beta-O-4 aryl ether linkages. Additional mechanistic insights gleaned from DFT calculations on the kinetics of key elementary reaction steps will also be presented, as well as a few thoughts on the significant contributions of Jim Franz to this area of free radical chemistry.

Buchanan III, A C [ORNL; Kidder, Michelle [ORNL; Beste, Ariana [ORNL; Britt, Phillip F [ORNL

2012-01-01T23:59:59.000Z

231

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

SciTech Connect

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.

Donald Gautier; Timothy Klett

2008-12-31T23:59:59.000Z

232

Brine-Driven Eddies under Sea Ice Leads and Their Impact on the Arctic Ocean Mixed Layer  

Science Conference Proceedings (OSTI)

Eddy generation induced by a line-shaped salt flux under a sea ice lead and associated salt transport are investigated using a three-dimensional numerical model. The model is designed to represent a typical condition for the wintertime Arctic ...

Yoshimasa Matsumura; Hiroyasu Hasumi

2008-01-01T23:59:59.000Z

233

The Seasonal Atmospheric Response to Projected Arctic Sea Ice Loss in the Late Twenty-First Century  

Science Conference Proceedings (OSTI)

The authors investigate the atmospheric response to projected Arctic sea ice loss at the end of the twenty-first century using an atmospheric general circulation model (GCM) coupled to a land surface model. The response was obtained from two 60-...

Clara Deser; Robert Tomas; Michael Alexander; David Lawrence

2010-01-01T23:59:59.000Z

234

A New Paradigm for Optimizing Hybrid Simulations of Rare Event Modeling for Complex Systems  

E-Print Network (OSTI)

-scale complex systems. Most complex systems such as our cities, national air space, nuclear power plants complex systems such as our cities, national air space, nuclear power plants, theme parks and global

Cook, Jeanine

235

Polyethylene Pipe Failure in the Arctic - Programmaster.org  

Science Conference Proceedings (OSTI)

In the current study, a new high density polyethylene (HDPE) pipe in the Arctic region of ... Heat Tint Effects on General Corrosion Resistance of Stainless Steels .

236

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

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

2. Analysis Discussion Resource Assessment The USGS most recent assessment of oil and gas resources of ANWR Coastal Plain (The Oil and Gas Resource Potential of the Arctic...

237

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 Glossary ANILCA: Alaska National Interest Lands Conservation Act ANS:...

238

Complex state found in the colossal magnetoresistance regime of models for manganites  

Science Conference Proceedings (OSTI)

The colossal magnetoresistance (CMR) effect of manganites is widely believed to be caused by the competition between a ferromagnetic (FM) metallic state induced by the double-exchange mechanism and an insulator with complex spin, charge, and orbital order. Recent computational studies in small clusters have indeed reported a CMR precisely near the frontier between those two states at a realistic hole density x = 1/4. However, the detailed characteristics of the competing insulator were not fully understood in those previous investigations. This insulator is expected to display special properties that lead to the CMR; otherwise any competition between ferromagnetic and antiferromagnetic states would induce such an effect, which is not the case experimentally. In this report, the competing insulator at electronic density x = 1/4 and in the CMR regime is studied in detail using the double-exchange two-orbital model with Jahn-Teller lattice distortions on two-dimensional clusters, employing a careful large-scale cooling down process in the Monte Carlo simulations to avoid being trapped in metastable states. Our investigations show that this competing insulator has an unexpected complex structure, involving diagonal stripes with alternating regions displaying FM and CE-like order. The level of complexity of this new state even surpasses that of the recently unveiled spin-orthogonal-stripe states and their associated high degeneracy. This new state complements the long-standing scenario of phase separation, since the alternating FM-CE pattern appears even in the clean limit. The present and recent investigations are also in agreement with the many glassy characteristics of the CMR state found experimentally, due to the high degeneracy of the insulating states involved in the process. Results for the spin-structure factor of the new states are also here provided to facilitate the analysis of neutron scattering experiments for these materials.

Sen, Cengiz [ORNL; Liang, Shuhua [ORNL; Dagotto, Elbio R [ORNL

2012-01-01T23:59:59.000Z

239

A hypertext model for accessing complex information: the reconstruction of a journey through Italy and Greece  

E-Print Network (OSTI)

The objective of this study is to construct a model of a computer based hypertext environment to enable easier access to complex information while providing the viewer with greater insight into a particular subject matter than could traditional text. The study addresses the importance of active participation and the relationship of new knowledge with existing knowledge, both of which the hypertext environment supports. The project will compile my postcards, sketches and journal entries which were gathered during a semester long study abroad program in Italy. The hypertext will provide the viewer with an opportunity to choose items of personal interest and experience the Italian culture in a way which is specific to each person. The project will be organized geographically, to simulate the traveling experience. It will feature various levels of personal involvement, allowing the viewer to merely observe images of sites, or to explore deeply into the culture and the people through my documented experiences. The goal is to present many facets of a complex land and culture within a medium better suited than traditional text to allowing the user choices as to how they wish to explore such an environment.

Parrish, David Allen

1995-01-01T23:59:59.000Z

240

Climate-derived tensions in Arctic security.  

Science Conference Proceedings (OSTI)

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.

Backus, George A.; Strickland, James Hassler

2008-09-01T23:59:59.000Z

Note: This page contains sample records for the topic "modeling complex arctic" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


241

Can we assess the model complexity for a bioprocess ? Theory and example of the anaerobic digestion process  

E-Print Network (OSTI)

Can we assess the model complexity for a bioprocess ? Theory and example of the anaerobic digestion the bioreactor. This provides the dimension of K. The method is applied to data from an anaerobic digestion can be obtained with 2 biomasses. Keywords Anaerobic digestion; Bioreactors; Modelling; Nonlinear

Paris-Sud XI, Université de

242

Source Attribution of Light Absorbing Aerosol in Arctic Snow  

NLE Websites -- All DOE Office Websites (Extended Search)

Source Attribution of Light Absorbing Source Attribution of Light Absorbing Aerosol in Arctic Snow (Preliminary analysis of 2008-2009 data) Outline * Receptor modeling overview * Results from 2007 data set * New goals arising from analysis of 2007 data * New data for 2008 * New data for 2009 * Tentative conclusions * Future analysis i Factor profiles from 2007 analysis Source attribution of Black Carbon from 2007 analysis Goals/Issues suggested by the analysis of the 2007 data set * Are there seasonal differences in the source strengths? * Are there other LAA chemical components besides black carbon. What are their sources? * Can the various data sets available (e.g., 2007, 2008, 2009) be combined in a single large PMF analysis 2008 Data Set For Receptor Analysis * 42 samples from Eastern Siberia including 4 depth profiles

243

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

Science Conference Proceedings (OSTI)

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.

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

2010-10-01T23:59:59.000Z

244

Use and Application of the ARCON96 Dispersion Model at the Y-12 Complex  

Science Conference Proceedings (OSTI)

The Atmospheric Relative Concentrations in Building Wakes computer code (ARCON96) was developed for the U.S. Nuclear Regulatory Commission (NRC) to calculate normalized concentrations in plumes from nuclear power plants at control room air intakes in the vicinity of hypothetical accidental releases. ARCON96 implements a straight-line Gaussian dispersion model with dispersion coefficients that are modified to account for low-wind-speed meander and building wake effects. These two modifications to the dispersion coefficients were benchmarked and justified in the ARCON96 code documentation. The code calculates {chi}/Q values (normalized concentrations) consistent with the methodology defined in NRC Regulatory Guide (RG) 1.145, position 3. Based on recent U. S. Department of Energy (DOE) acceptance of NRC RG 1.145, position 3 methodology for performing accident dispersion analyses, BWXT Y-12 L.L.C. evaluated the potential use and application for performing dispersion analyses at the Y-12 Complex. Using site specific meteorology inputs, a generic analysis (assuming ground-level releases) was performed to develop site-wide normalized concentrations for various distances to be used in consequence screening analyses. Additionally, the results were compared to other dispersion analysis models for confirmation of the results.

Walker, D.A.; Lee, D.W.; Miller, R.L.

2001-06-04T23:59:59.000Z

245

Attribution of Projected Changes in Atmospheric Moisture Transport in the Arctic: A Self-Organizing Map Perspective  

Science Conference Proceedings (OSTI)

Meridonal moisture transport into the Arctic derived from one simulation of the National Center for Atmospheric Research Community Climate System Model (CCSM3), spanning the periods of 1960–99, 2010–30, and 2070–89, is analyzed. The twenty-first-...

Natasa Skific; Jennifer A. Francis; John J. Cassano

2009-08-01T23:59:59.000Z

246

Arctic Sea Ice Decline: Observations, Projections, Mechanisms, and Implications  

E-Print Network (OSTI)

or phase space. In this work we con- sider the trajectory of sea ice in the ice thickness phase space. We175 Arctic Sea Ice Decline: Observations, Projections, Mechanisms, and Implications Geophysical Is the Trajectory of Arctic Sea Ice? Harry L. Stern and Ronald W. Lindsay Polar Science Center, Applied Physics

Lindsay, Ron

247

Near-Inertial Wave Propagation in the Western Arctic  

Science Conference Proceedings (OSTI)

From October 1997 through October 1998, the Surface Heat Budget of the Arctic (SHEBA) ice camp drifted across the western Arctic Ocean, from the central Canada Basin over the Northwind Ridge and across the Chukchi Cap. During much of this period, ...

Robert Pinkel

2005-05-01T23:59:59.000Z

248

AUTOMATIC GENERATION OF DIGITAL BUILDING MODELS FOR COMPLEX STRUCTURES FROM LIDAR DATA  

E-Print Network (OSTI)

Automated and reliable 3D reconstruction of man-made structures is important for various applications in virtual reality, city modeling, military training, etc. This paper is concerned with the automated generation of Digital Building Models (DBM) associated with complex structures comprised of small parts with different slopes, sizes, and shapes, from a LiDAR point cloud. The proposed methodology consists of a sequence of four steps: ground/non-ground point separation; building hypothesis generation; segmentation of planar patches and intermediate boundary generation; and boundary refinement and 3D wire frame generation. First, a novel ground/non-ground point classification technique is proposed based on the visibility analysis among ground and non-ground points in a synthesized perspective view. Once the LiDAR point cloud has been classified into ground and non-ground points, the non-ground points are analyzed and used to generate hypotheses of building instances based on the point attributes and the spatial relationships among the points. The third step of the proposed methodology segments each building hypothesis into a group of planar patches while simultaneously considering the attribute similarity and the spatial proximity among the points. The intermediate boundaries for segmented clusters are produced by using a modified convex hull algorithm. These boundaries are used as initial approximations of the planar surfaces comprising the building model of a given hypothesis. The last step of the proposed methodology utilizes these initial boundaries to come up with a refined set of boundaries, which are connected to produce a wire frame representing the DBM. The performance of the proposed methodology has been evaluated using experimental results from real data.

Changjae Kim; Ayman Habib; Yu-chuan Chang

2008-01-01T23:59:59.000Z

249

Towards A Novel Unified Framework for Developing Formal, Network and Validated Agent-Based Simulation Models of Complex Adaptive Systems  

E-Print Network (OSTI)

Literature on the modeling and simulation of complex adaptive systems (cas) has primarily advanced vertically in different scientific domains with scientists developing a variety of domain-specific approaches and applications. However, while cas researchers are inherently interested in an interdisciplinary comparison of models, to the best of our knowledge, there is currently no single unified framework for facilitating the development, comparison, communication and validation of models across different scientific domains. In this thesis, we propose first steps towards such a unified framework using a combination of agent-based and complex network-based modeling approaches and guidelines formulated in the form of a set of four levels of usage, which allow multidisciplinary researchers to adopt a suitable framework level on the basis of available data types, their research study objectives and expected outcomes, thus allowing them to better plan and conduct their respective research case studies. Firstly, the complex network modeling level of the proposed framework entails the development of appropriate complex network models for the case where interaction data of cas components is available, with the aim of detecting emergent patterns in the cas under

Muaz Ahmed; Khan Niazi

2011-01-01T23:59:59.000Z

250

Semantic-based web service discovery and chaining for building an Arctic spatial data infrastructure  

Science Conference Proceedings (OSTI)

Increasing interests in a global environment and climate change have led to studies focused on the changes in the multinational Arctic region. To facilitate Arctic research, a spatial data infrastructure (SDI), where Arctic data, information, and services ... Keywords: Arctic, Crawler, Hydrology, Knowledge base, Ontology, SDI, Semantic, Service chain

W. Li; C. Yang; D. Nebert; R. Raskin; P. Houser; H. Wu; Z. Li

2011-11-01T23:59:59.000Z

251

Arctic Lower Troposphere Observed Structure (ALTOS)  

NLE Websites -- All DOE Office Websites (Extended Search)

Lower Troposphere Observed Structure (ALTOS) Lower Troposphere Observed Structure (ALTOS) will raise and lower a heavily instrumented tethered balloon system at regular intervals in the lower 2 kilometers of the atmosphere at Oliktok Point. Data obtained during the ALTOS campaign will provide a statistically significant set of observed in situ cloud properties for validating retrieval algorithms and help scientists reduce the uncertainty in the radiative forcing and heating rates on hourly time scales. The data will also help researchers gain a better understanding of the driving processes that control climate changes and determine the state of the Arctic climate system. Collaborators Science Team: The Pennsylvania State University, Stratton

252

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

E-Print Network (OSTI)

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 ...

Wongviriyawong, Chanikarn Mint

2012-01-01T23:59:59.000Z

253

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

Science Conference Proceedings (OSTI)

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.

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

2010-11-01T23:59:59.000Z

254

A 20-year data set of surface longwave fluxes in the Arctic  

SciTech Connect

Creation of 20-year data set of surface infrared fluxes from satellite measurements. A reliable estimate of the surface downwelling longwave radiation flux (DLF) is a glaring void in available forcing data sets for models of Arctic sea ice and ocean circulation. We have developed a new method to estimate the DLF from a combination of satellite sounder retrievals and brightness temperatures from the TIROS Operational Vertical Sounder (TOVS), which has flown on NOAA polar-orbiting satellites continuously since late 1979. The overarching goal of this project was to generate a 20-year data set of surface downwelling longwave flux measurements from TOVS data over the Arctic Ocean. Daily gridded fields of DLF were produced with a spatial resolution of (100 km){sup 2} north of 60{sup o}N for 22.5 years rather than only 20. Surface measurements from the field station at Barrow, AK--part of the Atmospheric Radiation Measurement (ARM) Program --and from the Surface Heat Budget of the Arctic (SHEBA) were used to validate the satellite-derived fluxes and develop algorithm improvements for conditions that had resulted in systematic errors in early versions of the algorithm. The resulting data set has already been sent to two other investigators for incorporation into their research, and we will soon complete preparations to send the products to the National Snow and Ice Data Center and ARM data archive, where it can be disseminated to the scientific community.

Jennifer Francis

2004-06-15T23:59:59.000Z

255

Implications of Small-Scale Flow Features to Modeling Dispersion over Complex Terrain  

Science Conference Proceedings (OSTI)

Small-scale, topographically forced wind systems often have a strong influence on flow over complex terrain. A problem is that these systems are very difficult to measure, because of their limited spatial and temporal extent. They can be ...

R. M. Banta; L. D. Olivier; P. H. Gudiksen; R. Lange

1996-03-01T23:59:59.000Z

256

A Simple Model for Correcting Sodar and Lidar Errors in Complex Terrain  

Science Conference Proceedings (OSTI)

Ground-based sensing of wind profiles by sodars and lidars is becoming the standard for wind energy and other applications. However, there remain difficulties in complex terrain since the instruments sense wind components in spatially separated ...

Stuart Bradley

2012-12-01T23:59:59.000Z

257

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

E-Print Network (OSTI)

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 ...

Bartolomei, Jason E.

258

Improved representation of tropical Pacific ocean-atmosphere dynamics in an intermediate complexity climate model  

Science Conference Proceedings (OSTI)

A new anomaly coupling technique is introduced into a coarse-resolution dynamic climate model (LOVECLIM), improving the model’s representation of eastern equatorial Pacific surface temperature variability. The anomaly coupling amplifies the ...

Ryan L. Sriver; Axel Timmermann; Michael E. Mann; Klaus Keller; Hugues Goosse

259

Nighttime Cloud Detection Over the Arctic Using AVHRR Data  

NLE Websites -- All DOE Office Websites (Extended Search)

Cloud Detection Over the Arctic Cloud Detection Over the Arctic Using AVHRR Data D. A. Spangenberg, D. R. Doelling, and V. Chakrapani Analytical Services & Materials, Inc. Hampton, Virginia P. Minnis National Aeronautics and Space Administration Hampton, Virginia T. Uttal National Oceanic and Atmospheric Administration Boulder, Colorado Introduction Clouds play an important role in the Arctic energy budget. The magnitude and significance of the radiative impact of polar clouds, however, are not well known. Polar nocturnal clouds are often warmer or at the same temperature as the background snow surface, complicating cloud detection. Also, these clouds tend to be thin, with lower emittances than clouds occurring during the summer. Using only the infrared (IR) channels of satellite data to characterize cloud amount and distribution in the Arctic is

260

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...

Note: This page contains sample records for the topic "modeling complex arctic" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


261

Arctic Tropospheric Winds Derived from TOVS Satellite Retrievals  

Science Conference Proceedings (OSTI)

Accurate three-dimensional wind fields are essential for diagnosing a variety of important climate processes in the Arctic, such as the advection and deposition of heat and moisture, changes in circulation features, and transport of trace ...

Jennifer A. Francis; Elias Hunter; Cheng-Zhi Zou

2005-07-01T23:59:59.000Z

262

AMOC: Acoustic monitoring of the ocean climate of the Arctic  

Science Conference Proceedings (OSTI)

The overall objective of AMOC is to develop and design an acoustic system for long?term monitoring of the ocean temperature and ice thickness in the Arctic Ocean including the Fram Strait

Ola M. Johannessen; AMOC Group

1999-01-01T23:59:59.000Z

263

Statistical Characterization of Arctic Polar-Night Jet Oscillation Events  

Science Conference Proceedings (OSTI)

A novel diagnostic tool is presented, based on polar-cap temperature anomalies, for visualizing daily variability of the Arctic stratospheric polar vortex over multiple decades. This visualization illustrates the ubiquity of extended-time-scale ...

Peter Hitchcock; Theodore G. Shepherd; Gloria L. Manney

2013-03-01T23:59:59.000Z

264

Regional Variations of Moist Static Energy Flux into the Arctic  

Science Conference Proceedings (OSTI)

The authors investigate the climmological heating of the Arctic by the atmospheric moist static energy (MSE) flux from lower latitudes based on 25 years (November 1964–1989) of the GFDL dataset. During the five month winter period (NDJFM) the ...

James E. Overland; Philip Turet; Abraham H. Oort

1996-01-01T23:59:59.000Z

265

Autumnal Mixed-Phase Cloudy Boundary Layers in the Arctic  

Science Conference Proceedings (OSTI)

Two mixed-phase cloudy boundary layer events observed over the Arctic ice pack in autumn are extensively analyzed. The local dynamic and thermodynamic structure of the boundary layers is determined from aircraft measurements including analysis of ...

James O. Pinto

1998-06-01T23:59:59.000Z

266

Clouds at Arctic Atmospheric Observatories. Part II: Thermodynamic Phase Characteristics  

Science Conference Proceedings (OSTI)

Cloud phase defines many cloud properties and determines the ways in which clouds interact with other aspects of the climate system. The occurrence fraction and characteristics of clouds distinguished by their phase are examined at three Arctic ...

Matthew D. Shupe

2011-03-01T23:59:59.000Z

267

Multiparameter AVHRR-Derived Products for Arctic Climate Studies  

Science Conference Proceedings (OSTI)

Generation and sample applications of an integrated set of remotely sensed products for investigations of Arctic climate are described. Cloud fraction, ice surface temperature, surface albedo, downwelling radiative fluxes, ice motion vectors, and ...

Walter N. Meier; James A. Maslanik; Charles W. Fowler; Jeffrey R. Key

1997-01-01T23:59:59.000Z

268

Stratospheric Forcing of Surface Climate in the Arctic Oscillation  

Science Conference Proceedings (OSTI)

Diagnostic results are presented indicating that during the Arctic oscillation surface climate variations are directly forced by changes in the strength of the stratospheric polar vortex. To be specific, large-scale potential vorticity anomalies ...

Robert X. Black

2002-02-01T23:59:59.000Z

269

Intensification of Geostrophic Currents in the Canada Basin, Arctic Ocean  

Science Conference Proceedings (OSTI)

Continuous sampling of upper-ocean hydrographic data in the Canada Basin from various sources spanning from 2003 through 2011 provides an unprecedented opportunity to observe changes occurring in a major feature of the Arctic Ocean. In a 112-km-...

Miles G. McPhee

2013-05-01T23:59:59.000Z

270

Relationships between Arctic Sea Ice and Clouds during Autumn  

Science Conference Proceedings (OSTI)

The connection between sea ice variability and cloud cover over the Arctic seas during autumn is investigated by analyzing the 40-yr ECMWF Re-Analysis (ERA-40) products and the Television and Infrared Observation Satellite (TIROS) Operational ...

Axel J. Schweiger; Ron W. Lindsay; Steve Vavrus; Jennifer A. Francis

2008-09-01T23:59:59.000Z

271

Weather Forecasts by the WRF-ARW Model with the GSI Data Assimilation System in the Complex Terrain Areas of Southwest Asia  

Science Conference Proceedings (OSTI)

This paper will first describe the forecasting errors encountered from running the National Center for Atmospheric Research (NCAR) mesoscale model (the Advanced Research Weather Research and Forecasting model; ARW) in the complex terrain of ...

J. Xu; S. Rugg; L. Byerle; Z. Liu

2009-08-01T23:59:59.000Z

272

Primitive-Equation-Based Low-Order Models with Seasonal Cycle. Part II: Application to Complexity and Nonlinearity of Large-Scale Atmosphere Dynamics  

Science Conference Proceedings (OSTI)

A recently developed class of semiempirical low-order models is utilized for the reexamination of several aspects of the complexity and nonlinearity of large-scale dynamics in a GCM. Given their low dimensionality, these models are quite ...

Ulrich Achatz; J. D. Opsteegh

2003-02-01T23:59:59.000Z

273

Design options for an Arctic-class LNG carrier  

SciTech Connect

Melville Shipping Ltd., with Petro-Canada's Arctic pilot project, is designing the first commercial LNG system for year-round operations in the Canadian Arctic. Economical adaptation to the region will be maximized by the design combination of current icebreaking and LNG-transport technologies, with special concentration on the ship's hull form, hull structure and materials, LNG-containment system, and propulsion and transmission systems.

Dick, R.A.; Laskov, V.; Wainwright, J.

1979-01-01T23:59:59.000Z

274

Quality indicators for business process models from a gateway complexity perspective  

Science Conference Proceedings (OSTI)

Context: Quality assurance of business process models has been recognized as an important factor for modeling success at an enterprise level. Since quality of models might be subject to different interpretations, it should be addressed in the most objective ... Keywords: Business process model, Indicator, Measure, Threshold

Laura SáNchez-GonzáLez; FéLix GarcíA; Francisco Ruiz; Jan Mendling

2012-11-01T23:59:59.000Z

275

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

Science Conference Proceedings (OSTI)

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.

Brown, D L

2009-05-01T23:59:59.000Z

276

A supply chain paradigm to model business pprocesses at the Y-12 National Security Complex  

Science Conference Proceedings (OSTI)

The NNSA's Y-12 National Security Complex is a manufacturing facility operated by BWXT Y-12. Y-12's missions include ensuring the US' nuclear weapons deterrent, storing nuclear materials, and fueling US naval reactors. In order to understand the impacts ...

Reid Kress; Jack Dixon; Tom Insalaco; Richard Rinehart

2007-12-01T23:59:59.000Z

277

Renormalization of Orientable Non-Commutative Complex $?^6_3$ Model  

E-Print Network (OSTI)

In this paper we prove that the Grosse-Wulkenhaar type non-commutative orientable complex scalar $\\phi^6_3$ theory, with two non-commutative coordinates and the third one commuting with the other two, is renormalizable to all orders in perturbation theory. Our proof relies on a multiscale analysis in x space.

Zhituo Wang; Shaolong Wan

2007-10-15T23:59:59.000Z

278

Modeling the structure and dynamics of the consonant inventories: a complex network approach  

Science Conference Proceedings (OSTI)

We study the self-organization of the consonant inventories through a complex network approach. We observe that the distribution of occurrence as well as co-occurrence of the consonants across languages follow a power-law behavior. The co-occurrence ...

Animesh Mukherjee; Monojit Choudhury; Anupam Basu; Niloy Ganguly

2008-08-01T23:59:59.000Z

279

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

Science Conference Proceedings (OSTI)

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

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

2011-02-14T23:59:59.000Z

280

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

SciTech Connect

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

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

2011-02-14T23:59:59.000Z

Note: This page contains sample records for the topic "modeling complex arctic" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


281

Combining Case-Based and Model-Based Reasoning for the Diagnosis of Complex Devices  

Science Conference Proceedings (OSTI)

A novel approach to integrating case-based reasoning with model-based diagnosis is presented. This approach, called Experience Aided Diagnosis (EAD), uses the model of the device and the results of diagnostic tests to index and match cases representing past ... Keywords: case-based reasoning, hybrid problem-solving methods, model-based diagnosis

M. P. Féret; J. I. Glasgow

1997-01-01T23:59:59.000Z

282

Major Cloud Plumes in the Arctic and Their Relation to Fronts and Ice Movement  

Science Conference Proceedings (OSTI)

A study of the movement of orographic cloud plumes from one island to another in the Svalbard-Novaya Zemlya region of the Barents Sea revealed a close association with similar movements of arctic fronts. Strong northerly winds behind arctic ...

Robert W. Fett

1992-06-01T23:59:59.000Z

283

The Influence of Changes in Cloud Cover on Recent Surface Temperature Trends in the Arctic  

Science Conference Proceedings (OSTI)

A method is presented to assess the influence of changes in Arctic cloud cover on the surface temperature trend, allowing for a more robust diagnosis of causes for surface warming or cooling. Seasonal trends in satellite-derived Arctic surface ...

Yinghui Liu; Jeffrey R. Key; Xuanji Wang

2008-02-01T23:59:59.000Z

284

The Norwegian IPY–THORPEX: Polar Lows and Arctic Fronts during the 2008 Andøya Campaign  

Science Conference Proceedings (OSTI)

From a weather forecasting perspective, the Arctic poses particular challenges for mainly two reasons: 1) The observational data are sparse and 2) the weather phenomena responsible for severe weather, such as polar lows, Arctic fronts, and orographic ...

J. E. Kristjánsson; I. Barstad; T. Aspelien; I. Føre; Ø. Godøy; Ø. Hov; E. Irvine; T. Iversen; E. Kolstad; T. E. Nordeng; H. McInnes; R. Randriamampianina; J. Reuder; Ø. Saetra; M. Shapiro; T. Spengler; H. Ólafsson

2011-11-01T23:59:59.000Z

285

Modelling complex draft-tube flows using near-wall turbulence closures  

Science Conference Proceedings (OSTI)

This paper presents a finite-volume method for simulating flows through complex hydroturbine draft-tube configurations using near-wall turbulence closures. The method employs the artificial-compressibility pressure-velocity coupling approach in conjunction with multigrid acceleration for fast convergence on very fine grids. Calculations are carried out for a draft tube with two downstream piers on a computational mesh consisting of 1.2x10{sup 6} nodes. Comparisons of the computed results with measurements demonstrate the ability of the method to capture most experimental trends with reasonable accuracy. Calculated three-dimensional particle traces reveal very complex flow features in the vicinity of the piers, including horse-shoe longitudinal vortices and and regions of flow reversal.

Ventikos, Y.; Sotiropoulos, F. [Georgia Institute of Technology, Atlanta, GA (United States). School of Civil and Environmental Engineering; Patel, V.C. [Univ. of Iowa, Iowa City, IA (United States). Iowa Institute of Hydraulic Research

1996-12-31T23:59:59.000Z

286

Geochemistry of clathrate-derived methane in Arctic Ocean waters  

SciTech Connect

Alterations to the composition of seawater are estimated for microbial oxidation of methane from large polar clathrate destabilizations, which may arise in the coming century. Gas fluxes are taken from porous flow models of warming Arctic sediment. Plume spread parameters are then used to bracket the volume of dilution. Consumption stoichiometries for the marine methanotrophs are based on growth efficiency and elemental/enzyme composition data. The nutritional demand implied by extra CH{sub 4} removal is compared with supply in various high latitude water masses. For emissions sized to fit the shelf break, reaction potential begins at one hundred micromolar and falls to order ten a thousand kilometers downstream. Oxygen loss and carbon dioxide production are sufficient respectively to hypoxify and acidify poorly ventilated basins. Nitrogen and the monooxygenase transition metals may be depleted in some locations as well. Deprivation is implied relative to existing ecosystems, along with dispersal of the excess dissolved gas. Physical uncertainties are inherent in the clathrate abundance, patch size, outflow buoyancy and mixing rate. Microbial ecology is even less defined but may involve nutrient recycling and anaerobic oxidizers.

Elliott, S.M.; Reagan, M.T.; Moridis, G.J.; Cameron-Smith, P.J.

2010-03-15T23:59:59.000Z

287

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

SciTech Connect

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).

2011-10-01T23:59:59.000Z

288

Eggs Show Arctic Mercury Cycling May Be Linked to Ice Cover  

Science Conference Proceedings (OSTI)

... cycling of mercury in the Arctic biosphere. Credit: D. Roseneau, US Fish and Wildlife Service View hi-resolution image. ...

2011-01-20T23:59:59.000Z

289

Mathematical modelling, analysis and computation of some complex and nonlinear flow problems.  

E-Print Network (OSTI)

???This thesis consists of two parts: (I) modelling, analysis and computation of sweat transport in textile media; (II) unconditional convergence and optimal error analysis of… (more)

Li, Buyang (???)

2012-01-01T23:59:59.000Z

290

A Mathematical Framework for Agent Based Models of Complex Biological Networks  

E-Print Network (OSTI)

Agent-based modeling and simulation is a useful method to study biological phenomena in a wide range of fields, from molecular biology to ecology. Since there is currently no agreed-upon standard way to specify such models it is not always easy to use published models. Also, since model descriptions are not usually given in mathematical terms, it is difficult to bring mathematical analysis tools to bear, so that models are typically studied through simulation. In order to address this issue, Grimm et al. proposed a protocol for model specification, the so-called ODD protocol, which provides a standard way to describe models. This paper proposes an addition to the ODD protocol which allows the description of an agent-based model as a dynamical system, which provides access to computational and theoretical tools for its analysis. The mathematical framework is that of algebraic models, that is, time-discrete dynamical systems with algebraic structure. It is shown by way of several examples how this mathematical ...

Hinkelmann, Franziska; Jarrah, Abdul Salam; Laubenbacher, Reinhard

2010-01-01T23:59:59.000Z

291

Surface Complexation of Neptunium(V) onto Whole Cells and Cell Components of Shewanella alga: Modeling and Experimental Study  

Science Conference Proceedings (OSTI)

We systematically quantified surface complexation of Np(V) onto whole cells, cell wall, and extracellular polymeric substances (EPS) of Shewanella alga strain BrY. We first performed acid and base titrations and used the mathematical model FITEQL to estimate the concentrations and deprotonation constants of specific surface functional groups. Deprotonation constants most likely corresponded to a carboxyl group not associated with amino acids (pK{sub a} {approx} 5), a phosphoryl site (pK{sub a} {approx} 7.2), and an amine site (pK{sub a} > 10). We then carried out batch sorption experiments with Np(V) and each of the S. alga components as a function of pH. Since significant Np(V) sorption was observed on S. alga whole cells and its components in the pH range 2-5, we assumed the existence of a fourth site: a low-pK{sub a} carboxyl site (pK{sub a} {approx} 2.4) that is associated with amino acids. We used the SPECIATE submodel of the biogeochemical model CCBATCH to compute the stability constants for Np(V) complexation to each surface functional group. The stability constants were similar for each functional group on S. alga bacterial whole cells, cell walls, and EPS, and they explain the complicated sorption patterns when they are combined with the aqueous-phase speciation of Np(V). For pH XNH{sub 3}{sup +}, which complexed with NpO{sub 2}(CO{sub 3}){sub 3}{sup 5-}. The log K for NpO{sub 2}(CO{sub 3}){sub 3}{sup 5-} complexed onto the amine groups was 3.1-3.9. All of the log K values are similar to those of Np(V) complexes with aqueous carboxyl and N-containing carboxyl ligands. These results help quantify the role of surface complexation in defining actinide-microbiological interactions in the subsurface.

Deo, Randhir P.; Songkasiri, Warinthorn; Rittmann, Bruce E.; Reed, Donald T. (King Mongkut); (AZU); (LANL)

2012-04-30T23:59:59.000Z

292

A High-Resolution Air Pollution Model Suitable for Dispersion Studies in Complex Terrain  

Science Conference Proceedings (OSTI)

The development of an air pollution transport model that uses an expanding terrain-following coordinate with high resolution in analytic form near the surface and a high-order accurate transport algorithm is described. The model is designed to be ...

Ming Liu; John J. Carroll

1996-10-01T23:59:59.000Z

293

Internal variability in projections of twenty-first century Arctic sea ice loss: Role of the large-scale atmospheric circulation  

Science Conference Proceedings (OSTI)

Internal variability in twenty-first century summer Arctic sea ice loss and its relationship to the large-scale atmospheric circulation is investigated in a 39-member Community Climate System Model version 3 (CCSM3) ensemble for the period 2000–...

Justin J. Wettstein; Clara Deser

294

The Role of Sea Ice Thickness Distribution in the Arctic Sea Ice Potential Predictability: A Diagnostic Approach with a Coupled GCM  

Science Conference Proceedings (OSTI)

The intrinsic seasonal predictability of Arctic sea ice is investigated in a 400-yr-long preindustrial simulation performed with the Centre National de Recherches Météorologiques Coupled Global Climate Model, version 3.3 (CNRM-CM3.3). The skill of ...

Matthieu Chevallier; David Salas-Mélia

2012-04-01T23:59:59.000Z

295

Preliminary Geospatial Analysis of Arctic Ocean Hydrocarbon Resources  

SciTech Connect

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.

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

2008-10-01T23:59:59.000Z

296

Horizontal Heat Fluxes over Complex Terrain Computed Using a Simple Mixed-Layer Model and a Numerical Model  

Science Conference Proceedings (OSTI)

The thermally induced local circulation over a periodic valley is simulated by a two-dimensional numerical model that does not include condensational processes. During the daytime of a clear, calm day, heat is transported from the mountainous ...

Fujio Kimura; Tuneo Kuwagata

1995-02-01T23:59:59.000Z

297

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

SciTech Connect

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.

Stuart Walsh; Shane Cherry; Lyle Roybal

2009-05-01T23:59:59.000Z

298

Sensitivity of a Complex Urban Air Quality Model to Input Data  

Science Conference Proceedings (OSTI)

In recent years, urban-scale photochemical simulation models have been developed that are of practical value for predicting air quality and analyzing the impacts of alternative emission control strategies. Although the performance of some urban-...

Christian Seigneur; Thomas W. Tesche; Philip M. Roth; Larry E. Reid

1981-09-01T23:59:59.000Z

299

Steady Nonlinear Response of a Barotropic Quasi-unidimensional Model to Complex Topography  

Science Conference Proceedings (OSTI)

The response of a simple quasi-unidimensional barotropic model is studied. Wave-wave interaction, and bending the linear resonant response to the topographic forcing allows multiple equilibria if the zonal mean flow is assigned. The stationary ...

R. Benzi; S. Iarloir; G. Lippolis; A. Sutera

1988-11-01T23:59:59.000Z

300

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

E-Print Network (OSTI)

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 ...

Friedle, Simone

Note: This page contains sample records for the topic "modeling complex arctic" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


301

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

E-Print Network (OSTI)

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

Sokolov, Andrei P.

302

Bias Correction of Regional Climate Model Simulations in a Region of Complex Orography  

Science Conference Proceedings (OSTI)

This study presents a method to correct regional climate model (RCM) outputs using observations from automatic weather stations. The correction applies a nonlinear procedure, which recently appeared in the literature, to both precipitation and ...

Roger Bordoy; Paolo Burlando

2013-01-01T23:59:59.000Z

303

Calibrating a Land Surface Model of Varying Complexity Using Multicriteria Methods and the Cabauw Dataset  

Science Conference Proceedings (OSTI)

The multicriteria methodology, which provides a means to estimate optimal ranges for land surface model parameter values via calibration, is evaluated. Following calibration, differences between schemes resulting from effective parameter values ...

Y. Xia; A. J. Pitman; H. V. Gupta; M. Leplastrier; A. Henderson-Sellers; L. A. Bastidas

2002-04-01T23:59:59.000Z

304

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

Science Conference Proceedings (OSTI)

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.

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

305

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

Science Conference Proceedings (OSTI)

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.

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

306

ARM - Publications: Science Team Meeting Documents: An Arctic Springtime  

NLE Websites -- All DOE Office Websites (Extended Search)

An Arctic Springtime Mixed-Phase Cloudy Boundary Layer observed during An Arctic Springtime Mixed-Phase Cloudy Boundary Layer observed during SHEBA Zuidema, Paquita RSMAS/MPO University of Miami Han, Yong NASA Goddard Space Flight Center Intrieri, Janet NOAA/Environmental Technology Laboratory Key, Jeffrey Boston University Lawson, Paul SPEC Inc. Matrosov, Sergey NOAA/Environmental Technology Laboratory Shupe, Matthew CIRES/NOAA/ETL Uttal, Taneil NOAA/Environmental Technology Laboratory The microphysical characteristics, radiative impact, and lifecycle of a long-lived, surface-based mixed-layer, mixed-phase cloud with an average temperature of approximately -20 C are presented and discussed. The cloud was observed during the Surface Heat Budget of the Arctic experiment from May 1 through May 10, 1998. Vertically-resolved properties of the liquid

307

ARM - Field Campaign - Arctic Winter Water Vapor IOP  

NLE Websites -- All DOE Office Websites (Extended Search)

govCampaignsArctic Winter Water Vapor IOP govCampaignsArctic Winter Water Vapor IOP Comments? We would love to hear from you! Send us a note below or call us at 1-888-ARM-DATA. Send Campaign : Arctic Winter Water Vapor IOP 2004.03.09 - 2004.04.09 Lead Scientist : Ed Westwater Data Availability http://www.etl.noaa.gov/programs/2004/wviop/data will contain quicklooks of all of the data. For data sets, see below. Summary During the IOP, the Ground-based Scanning Radiometer of NOAA/ETL, and the ARM MicroWave Radiometer and Microwave Profiler, yielded excellent data over a range of conditions. In all, angular-scanned and calibrated radiometric data from 22.345 to 380 GHz were taken. The Precipitable Water Vapor varied about an order of magnitude from 1 to 10 mm, and surface temperatures varied from about -10 to -40 deg. Celcius. Vaisala RS90

308

Towards a Characterization of Arctic Mixed-Phase Clouds  

NLE Websites -- All DOE Office Websites (Extended Search)

Towards a Characterization of Arctic Mixed-Phase Clouds Towards a Characterization of Arctic Mixed-Phase Clouds Shupe, Matthew CIRES/NOAA/ETL Kollias, Pavlos Brookhaven National Laboratory Category: Cloud Properties Mixed-phase clouds play a unique role in the Arctic, where the delicate balance of phases in these clouds can have a profound impact on the surface radiation balance and various cloud-atmosphere-radiation-surface feedback processes. A better understanding of these clouds is clearly important and has been a recent objective of the ARM program. To this end, multiple sensors including radar, lidar, and temperature soundings, have been utilized in an automated cloud type classification scheme for clouds observed at the North Slope of Alaska site. The performance of this new algorithm at identifying mixed-phase cloud conditions is compared with an

309

Designing Logical Rules to Model the Response of Biomolecular Networks with Complex Interactions: An Application to Cancer Modeling  

Science Conference Proceedings (OSTI)

We discuss the propagation of constraints in eukaryotic interaction networks in relation to model prediction and the identification of critical pathways. In order to cope with posttranslational interactions, we consider two types of nodes in the network, ... Keywords: Systems biology, regulatory networks, posttranslational effects, in-silico analysis, automatic reasoning, cancer.

Carito Guziolowski; Sylvain Blachon; Tatiana Baumuratova; Gautier Stoll; Ovidiu Radulescu; Anne Siegel

2011-09-01T23:59:59.000Z

310

Agent-Based Model Approach to Complex Phenomena in Real Economy  

E-Print Network (OSTI)

An agent-based model for firms' dynamics is developed. The model consists of firm agents with identical characteristic parameters and a bank agent. Dynamics of those agents is described by their balance sheets. Each firm tries to maximize its expected profit with possible risks in market. Infinite growth of a firm directed by the "profit maximization" principle is suppressed by a concept of "going concern". Possibility of bankruptcy of firms is also introduced by incorporating a retardation effect of information on firms' decision. The firms, mutually interacting through the monopolistic bank, become heterogeneous in the course of temporal evolution. Statistical properties of firms' dynamics obtained by simulations based on the model are discussed in light of observations in the real economy.

Iyetomi, Hiroshi; Fujiwara, Yoshi; Ikeda, Yuichi; Souma, Wataru

2009-01-01T23:59:59.000Z

311

Extreme Value Statistics of the Total Energy in an Intermediate-Complexity Model of the Midlatitude Atmospheric Jet. Part I: Stationary Case  

Science Conference Proceedings (OSTI)

A baroclinic model of intermediate complexity for the atmospheric jet at middle latitudes is used as a stochastic generator of atmosphere-like time series. In this case, time series of the total energy of the system are considered. Statistical ...

Mara Felici; Valerio Lucarini; Antonio Speranza; Renato Vitolo

2007-07-01T23:59:59.000Z

312

Neptunium (V) Adsorption to a Halophilic Bacterium Under High Ionic Strength Conditions: A Surface Complexation Modeling Approach  

Science Conference Proceedings (OSTI)

Rationale for experimental design: Np(V) -- important as analog for Pu(V) and for HLW scenarios; High ionic strength -- relevant to salt-based repositories such as the WIPP; Halophilic microorganisms -- representative of high ionic strength environments. For the first time showed: Significant adsorbant to halophilic microorganisms over entire pH range under high ionic strength conditions; Strong influence of ionic strength with increasing adsorption with increasing ionic strength (in contrast to trends of previous low ionic strength studies); Effect of aqueous Np(V) and bacterial surface site speciation on adsorption; and Developed thermodynamic models that can be incorporated into geochemical speciation models to aid in the prediction of the fate and transport of Np(V) in more complex systems.

Ams, David A [Los Alamos National Laboratory

2012-06-11T23:59:59.000Z

313

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

E-Print Network (OSTI)

on the solar surface. These features correspond to the tops of submerged magnetic flux tubes, and coronal field lines often connect one flux tube to another, defining a pattern of inter­linkage. Using a model field­linkage. If the coronal field were current free then motions of the magnetic features would change the inter

Longcope, Dana

314

Employing description logics in Ambient Intelligence for modeling and reasoning about complex situations  

Science Conference Proceedings (OSTI)

Ambient Intelligence systems need to represent information about their environment and recognize relevant situations to perform appropriate actions proactively and autonomously. The context information gathered by these systems comes with imperfections ... Keywords: OWL DL, Situation-awareness, description logics, modeling context information, reasoning services

Thomas Springer; Anni-Yasmin Turhan

2009-08-01T23:59:59.000Z

315

The complex fuzzy system forecasting model based on triangular fuzzy robust wavelet ?-support vector machine  

Science Conference Proceedings (OSTI)

This paper presents a new version of fuzzy wavelet support vector regression machine to forecast the nonlinear fuzzy system with multi-dimensional input variables. The input and output variables of the proposed model are described as triangular fuzzy ... Keywords: Fuzzy ?-support vector machine, Fuzzy system forecasting, Particle swarm optimization, Wavelet kernel function

Qi Wu

2011-11-01T23:59:59.000Z

316

The Arctic Lower Troposphere Observed Structure (ALTOS) Campaign  

SciTech Connect

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.

Verlinde, J

2010-10-18T23:59:59.000Z

317

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

SciTech Connect

A comprehensive dataset of microphysical and radiative properties of aerosols and clouds in the arctic boundary layer in the vicinity of Barrow, Alaska was collected in April 2008 during the Indirect and Semi-Direct Aerosol Campaign (ISDAC) sponsored by the Department of Energy Atmospheric Radiation Measurement (ARM) and Atmospheric Science Programs. The primary aim of ISDAC was to examine indirect effects of aerosols on clouds that contain both liquid and ice water. The experiment utilized the ARM permanent observational facilities at the North Slope of Alaska (NSA) in Barrow. These include a cloud radar, a polarized micropulse lidar, and an atmospheric emitted radiance interferometer as well as instruments specially deployed for ISDAC measuring aerosol, ice fog, precipitation and spectral shortwave radiation. The National Research Council of Canada Convair-580 flew 27 sorties during ISDAC, collecting data using an unprecedented 42 cloud and aerosol instruments for more than 100 hours on 12 different days. Data were obtained above, below and within single-layer stratus on 8 April and 26 April 2008. These data enable a process-oriented understanding of how aerosols affect the microphysical and radiative properties of arctic clouds influenced by different surface conditions. Observations acquired on a heavily polluted day, 19 April 2008, are enhancing this understanding. Data acquired in cirrus on transit flights between Fairbanks and Barrow are improving our understanding of the performance of cloud probes in ice. Ultimately the ISDAC data will be used to improve the representation of cloud and aerosol processes in models covering a variety of spatial and temporal scales, and to determine the extent to which long-term surface-based measurements can provide retrievals of aerosols, clouds, precipitation and radiative heating in the Arctic.

McFarquhar, Greg; Ghan, Steven J.; Verlinde, J.; Korolev, Alexei; Strapp, J. Walter; Schmid, Beat; Tomlinson, Jason M.; Wolde, Mengistu; Brooks, Sarah D.; Cziczo, Daniel J.; Dubey, Manvendra K.; Fan, Jiwen; Flynn, Connor J.; Gultepe, Ismail; Hubbe, John M.; Gilles, Mary K.; Laskin, Alexander; Lawson, Paul; Leaitch, W. R.; Liu, Peter S.; Liu, Xiaohong; Lubin, Dan; Mazzoleni, Claudio; Macdonald, A. M.; Moffet, Ryan C.; Morrison, H.; Ovchinnikov, Mikhail; Shupe, Matthew D.; Turner, David D.; Xie, Shaocheng; Zelenyuk, Alla; Bae, Kenny; Freer, Matthew; Glen, Andrew

2011-02-01T23:59:59.000Z

318

Arctic Oil and Natural Gas Potential Philip Budzik U.S. Energy Information Administration  

Gasoline and Diesel Fuel Update (EIA)

Arctic Oil and Natural Gas Potential Arctic Oil and Natural Gas Potential Philip Budzik U.S. Energy Information Administration Office of Integrated Analysis and Forecasting Oil and Gas Division October, 2009 Introduction The Arctic is defined as the Northern hemisphere region located north of the Arctic Circle, the circle of latitude where sunlight is uniquely present or absent for 24 continuous hours on the summer and winter solstices, respectively. The Arctic Circle spans the globe at 66.56° (66°34') north latitude (Figure 1). 1 The Arctic could hold about 22 percent of the world's undiscovered conventional oil and natural gas resources. The prospects for Arctic oil and natural gas production are discussed taking into consideration the nature of the resources, the cost of developing them, and the

319

The resilience and functional role of moss in boreal and arctic ecosystems  

Science Conference Proceedings (OSTI)

Mosses in boreal and arctic ecosystems are ubiquitous components of plant communities, represent an important component of plant diversity, and strongly influence the cycling of water, nutrients, energy and carbon. Here we use a literature review and synthesis as well as model simulations to explore the role of moss in ecological stability and resilience. Our literature review of moss community responses to disturbance showed all possible responses (increases, decreases, no change) within most disturbance categories in boreal and arctic regions. Our modeling simulations suggest that loss of moss within northern plant communities will reduce soil carbon accumulation primarily by influencing decomposition rates and soil nitrogen availability. While two models (HPM and STM-TEM) showed a significant effect of moss removal, results from the Biome-BGC and DVM-TEM models suggest that northern, moss-rich ecosystems would need to experience extreme perturbation before mosses were eliminated. We highlight a number of issues that have not been adequately explored in moss communities, such as functional redundancy and singularity, relationships between response and effect traits, phenotypical plasticity in traits, and whether the effects of moss on ecosystem processes scale with local abundance. We also suggest that as more models explore issues related to ecological resilience, issues related to both parameter and conceptual uncertainty should be addressed: are the models more limited by uncertainty in the parameterization of the processes included or by what is not represented in the model at all? It seems clear from our review that mosses need to be incorporated into models as one or more plant functional types, but more empirical work is needed to determine how to best aggregate species.

Turetsky, Merritt; Bond-Lamberty, Benjamin; Euskirchen, Eugenie S.; Talbot, Julie; Frolking, Steve; McGuire, A. David; Tuittila, Eeva-Stiina

2012-08-24T23:59:59.000Z

320

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

Science Conference Proceedings (OSTI)

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 (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.

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

Note: This page contains sample records for the topic "modeling complex arctic" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


321

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

SciTech Connect

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.

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

2009-04-10T23:59:59.000Z

322

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

SciTech Connect

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.

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

2008-02-18T23:59:59.000Z

323

Spatial and Temporal Variability of Aerosol Particles in Arctic Spring  

SciTech Connect

The objective of this work is to investigate the variability in the particle number concentration that may affect climate change assessment for Arctic regions. The Indirect and Semi-Direct Aerosol Campaign (ISDAC) was conducted in April 2008, in the vicinities of Fairbanks and Barrow, Alaska. Measurements of particle number concentrations and size distributions were conducted using a Passive Cavity Aerosol Spectrometer Probe (PCASP-100X) mounted under the Convair-580 aircraft wing. Total number concentration of particles (Na) with diameters in the range 0.12-3 ?m was determined for polluted and clean air masses during times when the air was free of clouds and/or precipitation. Variability in Na was considered for both vertical profiles and constant altitude (horizontal) flight legs. This variability can have important implications for estimates of particle properties used in global climate model (GCM) simulations. When aerosol particle layers were encountered, Na rapidly increased from 25 cm-3 up to 550 cm-3 within relatively clean air masses, and reached up to 2200 cm-3 within polluted air masses, dominated by biomass burning pollution. When averaging Na over different distance scales, it was found that Na=140 cm-3 represent an average value for the majority of the encountered clean cases; while Na=720 cm-3 is a mean for polluted cases dominated by biomass burning plumes. These estimates, however, would not capture the details of particle layers encountered during most of the flights. Average aerosol particle characteristics can be difficult to interpret, especially during polluted cases, due to small-scale spatial and temporal variability.

Shantz, Nicole C.; Gultepe, Ismail; Liu, Peter; Earle, Michael; Zelenyuk, Alla

2012-10-01T23:59:59.000Z

324

Developing custom fire behavior fuel models from ecologically complex fuel structures for upper Atlantic Coastal Plain forests.  

SciTech Connect

Currently geospatial fire behavior analyses are performed with an array of fire behavior modeling systems such as FARSITE, FlamMap, and the Large Fire Simulation System. These systems currently require standard or customized surface fire behavior fuel models as inputs that are often assigned through remote sensing information. The ability to handle hundreds or thousands of measured surface fuelbeds representing the fine scale variation in fire behavior on the landscape is constrained in terms of creating compatible custom fire behavior fuel models. In this study, we demonstrate an objective method for taking ecologically complex fuelbeds from inventory observations and converting those into a set of custom fuel models that can be mapped to the original landscape. We use an original set of 629 fuel inventory plots measured on an 80,000 ha contiguous landscape in the upper Atlantic Coastal Plain of the southeastern United States. From models linking stand conditions to component fuel loads, we impute fuelbeds for over 6000 stands. These imputed fuelbeds were then converted to fire behavior parameters under extreme fuel moisture and wind conditions (97th percentile) using the fuel characteristic classification system (FCCS) to estimate surface fire rate of spread, surface fire flame length, shrub layer reaction intensity (heat load), non-woody layer reaction intensity, woody layer reaction intensity, and litter-lichen-moss layer reaction intensity. We performed hierarchical cluster analysis of the stands based on the values of the fire behavior parameters. The resulting 7 clusters were the basis for the development of 7 custom fire behavior fuel models from the cluster centroids that were calibrated against the FCCS point data for wind and fuel moisture. The latter process resulted in calibration against flame length as it was difficult to obtain a simultaneous calibration against both rate of spread and flame length. The clusters based on FCCS fire behavior parameters represent reasonably identifiable stand conditions, being: (1) pine dominated stands with more litter and down woody debriscomponents than other stands, (2) hardwood and pine stands with no shrubs, (3) hardwood dominated stands with low shrub and high non-woody biomass and high down woody debris, (4) stands with high grass and forb (i.e., non-woody) biomass as well as substantial shrub biomass, (5) stands with both high shrub and litter biomass, (6) pine-mixed hardwood stands with moderate litter biomass and low shrub biomass, and (7) baldcypress-tupelo stands. Models representing these stand clusters generated flame lengths from 0.6 to 2.3 musing a 30 km h{sub 1} wind speed and fireline intensities of 100-1500 kW m{sub 1} that are typical within the range of experience on this landscape. The fuel models ranked 1 < 2 < 7 < 5 < 4 < 3 < 6 in terms of both flame length and fireline intensity. The method allows for ecologically complex data to be utilized in order to create a landscape representative of measured fuel conditions and to create models that interface with geospatial fire models.

Parresol, Bernard, R.; Scott, Joe, H.; Andreu, Anne; Prichard, Susan; Kurth, Laurie

2012-01-01T23:59:59.000Z

325

Arctic Ocean Warming Contributes to Reduced Polar Ice Cap  

Science Conference Proceedings (OSTI)

Analysis of modern and historical observations demonstrates that the temperature of the intermediate-depth (150–900 m) Atlantic water (AW) of the Arctic Ocean has increased in recent decades. The AW warming has been uneven in time; a local 1°C ...

Igor V. Polyakov; Leonid A. Timokhov; Vladimir A. Alexeev; Sheldon Bacon; Igor A. Dmitrenko; Louis Fortier; Ivan E. Frolov; Jean-Claude Gascard; Edmond Hansen; Vladimir V. Ivanov; Seymour Laxon; Cecilie Mauritzen; Don Perovich; Koji Shimada; Harper L. Simmons; Vladimir T. Sokolov; Michael Steele; John Toole

2010-12-01T23:59:59.000Z

326

Cirriform Rotor Cloud Observed on a Canadian Arctic Ice Cap  

Science Conference Proceedings (OSTI)

A thin rotor cloud was observed on the lee side of Penny Ice Cap in the Canadian Arctic on 21 April 1996. The cloud consisted of thin cirriform layers, so that its motion was clearly observed. By means of time-lapse camera photography, the ...

Hisashi Ozawa; Kumiko Goto-Azuma; Koyuru Iwanami; Roy M. Koerner

1998-06-01T23:59:59.000Z

327

Interannual variability of arctic landfast ice between 1976 and 2007  

Science Conference Proceedings (OSTI)

Analysis of weekly sea ice charts produced by the U.S. National Ice Center from 1976 to 2007 indicates large interannual variations in the averaged winter landfast ice extent around the Arctic Basin. During the 32-year period of the record, ...

Yanling Yu; Harry Stern; Charles Fowler; Florence Fetterer; James Maslanik

328

Observation of Ice Crystal Formation in Lower Arctic Atmosphere  

Science Conference Proceedings (OSTI)

Clear sky ice crystals or diamond dust displays are observed in polar regions, both remote and populated; when the temperature falls to ?20°C and where abundant sources of water vapor are present. In remote areas of the Arctic, these ice crystals ...

Takeshi Ohtake; Kolf Jayaweera; Ken-Ichi Sakurai

1982-12-01T23:59:59.000Z

329

Hafnium isotopes in Arctic Ocean water Bettina Zimmermann a  

E-Print Network (OSTI)

-GEOMAR, 24148 Kiel, Germany d Laboratory for Isotope Geology, Swedish Museum of Natural History, Box 50007, SEHafnium isotopes in Arctic Ocean water Bettina Zimmermann a , Don Porcelli b,*, Martin Frank c-104 05 Stockholm, Sweden e Department of Geology, Wayne State University, Detroit, MI 48202, USA f

Baskaran, Mark

330

The Water and Energy Budget of the Arctic Atmosphere  

Science Conference Proceedings (OSTI)

The Arctic plays a major role in the global circulation, and its water and energy budget is not as well explored as that in other regions of the world. The aim of this study is to calculate the climatological mean water and energy fluxes ...

Tido Semmler; Daniela Jacob; K. Heinke Schlünzen; Ralf Podzun

2005-07-01T23:59:59.000Z

331

The Gravity Wave–Arctic Stratospheric Vortex Interaction  

Science Conference Proceedings (OSTI)

Four hundred and twenty-two nights of stratospheric gravity wave observations were obtained with a Rayleigh lidar in the High Arctic at Eureka (80°N, 86°W) during six wintertime measurement campaigns between 1992/93 and 1997/98. The measurements ...

Thomas J. Duck; James A. Whiteway; Allan I. Carswell

2001-12-01T23:59:59.000Z

332

Warming Trends in the Arctic from Clear Sky Satellite Observations  

Science Conference Proceedings (OSTI)

Satellite thermal infrared data on surface temperatures provide pan-Arctic coverage from 1981 to 2001 during cloud-free conditions and reveal large warming anomalies in the 1990s compared to the 1980s and regional variability in the trend. The ...

Josefino C. Comiso

2003-11-01T23:59:59.000Z

333

Estimation of Heat and Mass Fluxes Over Arctic Leads  

Science Conference Proceedings (OSTI)

Recent work on the turbulent transfer of scalar quantities following a step increase in the surface value of the scalar is directly applicable to the problem of estimating heat and mass transfer from Arctic leads in winter. If the turbulent flux ...

Edgar L. Andreas

1980-12-01T23:59:59.000Z

334

The Summer Cyclone Maximum over the Central Arctic Ocean  

Science Conference Proceedings (OSTI)

A fascinating feature of the northern high-latitude circulation is a prominent summer maximum in cyclone activity over the Arctic Ocean, centered near the North Pole in the long-term mean. This pattern is associated with the influx of lows ...

Mark C. Serreze; Andrew P. Barrett

2008-03-01T23:59:59.000Z

335

Synoptic Activity in the Arctic Basin, 1979–85  

Science Conference Proceedings (OSTI)

Synoptic activity in the Arctic basin from 70°–907deg;N is examined for the period 1979–85, using improved pressure analyses incorporating data from a network of drifting buoys. Geographical and seasonal variations in cyclone and anticyclone ...

Mark C. Serreze; Roger G. Barry

1988-12-01T23:59:59.000Z

336

Flawed Assumptions, Models and Decision Making: Misconceptions Concerning Human Elements in Complex System  

SciTech Connect

The history of high consequence accidents is rich with events wherein the actions, or inaction, of humans was critical to the sequence of events preceding the accident. Moreover, it has been reported that human error may contribute to 80% of accidents, if not more (dougherty and Fragola, 1988). Within the safety community, this reality is widely recognized and there is a substantially greater awareness of the human contribution to system safety today than has ever existed in the past. Despite these facts, and some measurable reduction in accident rates, when accidents do occur, there is a common lament. No matter how hard we try, we continue to have accidents. Accompanying this lament, there is often bewilderment expressed in statements such as, ''There's no explanation for why he/she did what they did''. It is believed that these statements are a symptom of inadequacies in how they think about humans and their role within technological systems. In particular, while there has never been a greater awareness of human factors, conceptual models of human involvement in engineered systems are often incomplete and in some cases, inaccurate.

FORSYTHE,JAMES C.; WENNER,CAREN A.

1999-11-03T23:59:59.000Z

337

Influence of initial and boundary conditions for ozone modeling in very complex terrains: A case study in the northeastern Iberian Peninsula  

Science Conference Proceedings (OSTI)

Initial (IC) and boundary conditions (BC) are required in order to solve the set of stiff differential equations included in air quality models. In this work, the influences of IC-BC are analyzed in the northeastern Iberian Peninsula (NEIP) by applying ... Keywords: Air quality modeling, Complex terrains, Initial and boundary conditions, Ozone, Photochemistry

Pedro Jiménez; René Parra; José M. Baldasano

2007-09-01T23:59:59.000Z

338

Potential impacts of the Arctic on interannual and interdecadal summer precipitation over China  

SciTech Connect

After the end of the 1970s, there has been a tendency for enhanced summer precipitation over South China and the Yangtze River valley and drought over North China and Northeastern China. Coincidentally, Arctic ice concentration has decreased since the late 1970s, with larger reduction in summer than spring. However, the Arctic warming is more significant in spring than summer, suggesting that spring Arctic conditions could be more important in their remote impacts. This study investigates the potential impacts of the Arctic on summer precipitation in China. The leading spatial patterns and time coefficients of the unfiltered, interannual, and interdecadal precipitation (1960-2008) modes were analyzed and compared using empirical orthogonal function (EOF) analysis, which shows that the first three EOFs can capture the principal precipitation patterns (northern, central and southern patterns) over eastern China. Regression of the Arctic spring and summer temperature onto the time coefficients of the leading interannual and interdecadal precipitation modes shows that interdecadal summer precipitation in China is related to the Arctic spring warming, but the relationship with Arctic summer temperature is weak. Moreover, no notable relationships were found between the first three modes of interannual precipitation and Arctic spring or summer temperatures. Finally, correlations between summer precipitation and the Arctic Oscillation (AO) index from January to August were investigated, which indicate that summer precipitation in China correlates with AO only to some extent. Overall, this study suggests important relationships between the Arctic spring temperature and summer precipitation over China at the interdecadal time scale.

Li, Yuefeng; Leung, Lai-Yung R.

2013-02-01T23:59:59.000Z

339

Arctic National Wildlife Refuge: oil field or wilderness  

Science Conference Proceedings (OSTI)

The second session of the 100th Congress will see continued debate over the prospect of oil and gas drilling on a 19-million-acre expanse of mountains and tundra known as the Arctic National Wildlife Refuge (ANWR). The arctic refuge, most of which lies above the Arctic Circle, is larger than any refuges in the lower 48 states. Because of its size, the area supports a broad range of linked ecosystems. Of particular concern is the 1.5-million-acre coastal plain, which may be targeted for development. The coastal plain provides a home, at least part of the year, to Alaska's porcupine caribou. The coastal plain also supports many other forms of wildlife-including the wolf, arctic fox, brown bear, polar bear, and arctic peregrine falcon, which is listed as a threatened species. The potential effects of drilling projects extend beyond loss of wildlife; they include desecration of the land itself. Although few members of Congress deny the value of protecting the amazing variety of life on the coastal plain, some insist that limited drilling could be conducted without destroying crucial habitat. Last July, the department tentatively divided some of the targeted lands among native corporations in preparation for leasing to oil companies. In response to what was felt to be an attempt to overstep congressional authority, the House passed HR 2629, banning this kind of land deal without congressional approval. In essence, the measure reiterated congressional authority provided by the Alaska National Interest Lands Conservation Act (ANILCA) of 1980. This act mandated the study of environmental threats and oil potential by the Department of Interior, while putting the ANWR coastal plain off-limits to development without an explicit congressional directive.

Spitler, A.

1987-11-01T23:59:59.000Z

340

A FIRE-ACE/SHEBA Case Study of Mixed-Phase Arctic Boundary Layer Clouds: Entrainment Rate Limitations on Rapid Primary Ice Nucleation Processes  

Science Conference Proceedings (OSTI)

Observations of long-lived mixed-phase Arctic boundary layer clouds on 7 May 1998 during the First International Satellite Cloud Climatology Project (ISCCP) Regional Experiment (FIRE)–Arctic Cloud Experiment (ACE)/Surface Heat Budget of the Arctic ...

Ann M. Fridlind; Bastiaan van Diedenhoven; Andrew S. Ackerman; Alexander Avramov; Agnieszka Mrowiec; Hugh Morrison; Paquita Zuidema; Matthew D. Shupe

2012-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "modeling complex arctic" from the National Library of EnergyBeta (NLEBeta).
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341

Modelling the X-ray polarimetric signatures of complex geometry: the case study of the "changing look" AGN NGC 1365  

E-Print Network (OSTI)

"Changing look" Active Galactic Nuclei (AGN) are a subset of Seyfert galaxies characterized by rapid transitions between Compton-thin and Compton-thick regimes. In their Compton-thin state, the central engine is less obscured, hence spectroscopy or timing observations can probe their innermost structures. However, it is not clear if the observed emission features and the Compton hump are associated with relativistic reflection onto the accretion disc, or complex absorption by distant, absorbing gas clouds passing by the observer's line-of-sight. Here, we investigate these two scenarios under the scope of X-ray polarimetry, providing the first polarisation predictions for an archetypal "changing look" AGN: NGC 1365. We explore the resulting polarisation emerging from lamp-post emission and scattering off an accretion disc in the immediate vicinity of a supermassive black hole. The computed polarisation signatures are compared to the results of an absorption-dominated model, where high column density gas partially covers the central source. While the shape of the polarisation spectrum is similar, the two models differ in net polarisation percentage, with the relativistic reflection scenario producing significantly stronger polarisation. Additionally, the variation of the polarisation position angle is distinctly different between both scenarios: the reflection-dominated model produces smooth rotations of the polarisation angle with photon energy whereas circumnuclear absorption causes an orthogonal switch of the polarisation angle between the soft and the hard X-ray bands. By comparing the predicted polarisation of NGC 1365 to the detectability levels of X-ray polarimetry mission concepts proposed in the past, we demonstrate that with a large, soft X-ray observatory or a medium-sized mission equipped with a hard (6 - 35 keV) polarimeter, the correct interpretation would be unambiguous.

Frederic Marin; Delphine Porquet; Rene W. Goosmann; Michal Dovciak; Fabio Muleri; Nicolas Grosso; Vladimir Karas

2013-09-06T23:59:59.000Z

342

Arctic oil and natural gas resources - Today in Energy - U.S ...  

U.S. Energy Information Administration (EIA)

Wind › Geothermal › ... seals, whales, and other sea life. The adequacy of existing technology to manage offshore oil spills in an arctic environment is another ...

343

inner-sphere complexation of cations at the rutile-water interface: A concise surface structural interpretation with the CD and MUSIC model  

Science Conference Proceedings (OSTI)

Acid base reactivity and ion-interaction between mineral surfaces and aqueous solutions is most frequently investigated at the macroscopic scale as a function of pH. Experimental data are then rationalized by a variety of surface complexation models. These models are thermodynamically based which in principle does not require a molecular picture. The models are typically calibrated to relatively simple solid-electrolyte solution pairs and may provide poor descriptions of complex multicomponent mineral aqueous solutions, including those found in natural environments. Surface complexation models may be improved by incorporating molecular-scale surface structural information to constrain the modeling efforts. Here, we apply a concise, molecularly-constrained surface complexation model to a diverse suite of surface titration data for rutile and thereby begin to address the complexity of multi-component systems. Primary surface charging curves in NaCl, KCl, and RbCl electrolyte media were fit simultaneously using a charge distribution (CD) and multisite complexation (MUSIC) model [Hiemstra T. and Van Riemsdijk W. H. (1996) A surface structural approach to ion adsorption: the charge distribution (CD) model. J. Colloid Interf. Sci. 179, 488 508], coupled with a Basic Stern layer description of the electric double layer. In addition, data for the specific interaction of Ca2+ and Sr2+ with rutile, in NaCl and RbCl media, were modeled. In recent developments, spectroscopy, quantum calculations, and molecular simulations have shown that electrolyte and divalent cations are principally adsorbed in various inner-sphere configurations on the rutile 110 surface [Zhang Z., Fenter P., Cheng L., Sturchio N. C., Bedzyk M. J., Pr edota M., Bandura A., Kubicki J., Lvov S. N., Cummings P. T., Chialvo A. A., Ridley M. K., Be ne zeth P., Anovitz L., Palmer D. A., Machesky M. L. and Wesolowski D. J. (2004) Ion adsorption at the rutile water interface: linking molecular and macroscopic properties. Langmuir 20, 4954 4969]. Our CD modeling results are consistent with these adsorbed configurations provided adsorbed cation charge is allowed to be distributed between the surface (0-plane) and Stern plane (1-plane). Additionally, a complete description of our titration data required inclusion of outer-sphere binding, principally for Cl which was common to all solutions, but also for Rb+ and K+. These outer-sphere species were treated as point charges positioned at the Stern layer, and hence determined the Stern layer capacitance value. The modeling results demonstrate that a multi-component suite of experimental data can be successfully rationalized within a CD and MUSIC model using a Stern-based description of the EDL. Furthermore, the fitted CD values of the various inner-sphere complexes of the mono- and divalent ions can be linked to the microscopic structure of the surface complexes and other data found by spectroscopy as well as molecular dynamics (MD). For the Na+ ion, the fitted CD value points to the presence of bidenate inner-sphere complexation as suggested by a recent MD study. Moreover, its MD dominance quantitatively agrees with the CD model prediction. For Rb+, the presence of a tetradentate complex, as found by spectroscopy, agreed well with the fitted CD and its predicted presence was quantitatively in very good agreement with the amount found by spectroscopy.

Ridley, Mora K. [Texas Tech University, Lubbock; Hiemstra, T [Oak Ridge National Laboratory (ORNL); Van Riemsdijk, Willem H. [Wageningen University and Research Centre, The Netherlands; Machesky, Michael L. [Illinois State Water Survey, Champaign, IL

2009-01-01T23:59:59.000Z

344

Modeling Organic Aerosols in a Megacity: Comparison of Simple and Complex Representations of the Volatility Basis Set Approach  

Science Conference Proceedings (OSTI)

The Weather Research and Forecasting model coupled with chemistry (WRF-Chem) is modified to include a volatility basis set (VBS) treatment of secondary organic aerosol formation. The VBS approach, coupled with SAPRC-99 gas-phase chemistry mechanism, is used to model gas-particle partitioning and multiple generations of gas-phase oxidation of organic vapors. In addition to the detailed 9-species VBS, a simplified mechanism using 2 volatility species (2-species VBS) is developed and tested for similarity to the 9-species VBS in terms of both mass and oxygen-to-carbon ratios of organic aerosols in the atmosphere. WRF-Chem results are evaluated against field measurements of organic aerosols collected during the MILAGRO 2006 campaign in the vicinity of Mexico City. The simplified 2-species mechanism reduces the computational cost by a factor of 2 as compared to 9-species VBS. Both ground site and aircraft measurements suggest that the 9-species and 2-species VBS predictions of total organic aerosol mass as well as individual organic aerosol components including primary, secondary, and biomass burning are comparable in magnitude. In addition, oxygen-to-carbon ratio predictions from both approaches agree within 25%, providing evidence that the 2-species VBS is well suited to represent the complex evolution of organic aerosols. Model sensitivity to amount of anthropogenic semi-volatile and intermediate volatility (S/IVOC) precursor emissions is also examined by doubling the default emissions. Both the emission cases significantly under-predict primary organic aerosols in the city center and along aircraft flight transects. Secondary organic aerosols are predicted reasonably well along flight tracks surrounding the city, but are consistently over-predicted downwind of the city. Also, oxygen-to-carbon ratio predictions are significantly improved compared to prior studies by adding 15% oxygen mass per generation of oxidation; however, all modeling cases still under-predict these ratios downwind as compared to measurements, suggesting a need to further improve chemistry parameterizations of secondary organic aerosol formation.

Shrivastava, ManishKumar B.; Fast, Jerome D.; Easter, Richard C.; Gustafson, William I.; Zaveri, Rahul A.; Jimenez, Jose L.; Saide, Pablo; Hodzic, Alma

2011-07-13T23:59:59.000Z

345

Managing Complexity: Disease Control as a Complex Adaptive System  

Science Conference Proceedings (OSTI)

Trends in computer and communications technologies are enabling increased globalization and integration of enterprises, and corresponding increases of enterprise complexity.ï¾ ï¾ This article addresses management of this complexity using a complex adaptive ... Keywords: complex adaptive systems, disease control, strategic management, complexity, system models

William B. Rouse

2000-04-01T23:59:59.000Z

346

Surface Energy Balance on the Arctic Tundra: Measurements and Models  

Science Conference Proceedings (OSTI)

The progress made in the Land–Atmosphere–Ice Interactions Flux Study over the past 4 yr to fully characterize the biophysical fluxes in the snow-free tundra ecosystem and their relationship to climate and climate change is described. This paper ...

A. H. Lynch; F. S. Chapin III; L. D. Hinzman; W. Wu; E. Lilly; G. Vourlitis; E. Kim

1999-08-01T23:59:59.000Z

347

New Algorithm Enables Unprecedented Sampling, Modeling of Arctic...  

NLE Websites -- All DOE Office Websites (Extended Search)

the U.S. Department of Agriculture's Forest Service used a unique algorithm to divide the state of Alaska into "bioclimatic" regions based on the results of climate and permafrost...

348

The Melting of Ice in the Arctic Ocean: The Influence of Double-Diffusive Transport of Heat from Below  

Science Conference Proceedings (OSTI)

This investigation was originally prompted by two oceanographic observations: an increased rate of melting of sea ice in the Arctic Ocean, and the advance of an anomalously warm tongue of Atlantic water intruding across the Arctic below the ...

J. S. Turner

2010-01-01T23:59:59.000Z

349

Arctic ocean long-term acoustic monitoring : ambient noise, environmental correlates, and transients north of Barrow, Alaska  

E-Print Network (OSTI)

Ambient Noise in the Arctic Ocean,” J. Acoust. Soc. Am. Vol.for sound speed in the oceans,” J. Acoust. Soc. Am. Vol. 70,Pritchard, R. S. , “Arctic Ocean Background Noise Caused by

Roth, Ethan H.

2008-01-01T23:59:59.000Z

350

Advancement into the Arctic Region for Bioactive Sponge Secondary Metabolites  

E-Print Network (OSTI)

Abstract: Porifera have long been a reservoir for the discovery of bioactive compounds and drug discovery. Most research in the area has focused on sponges from tropical and temperate waters, but more recently the focus has shifted to the less accessible colder waters of the Antarctic and, to a lesser extent, the Arctic. The Antarctic region in particular has been a more popular location for natural products discovery and has provided promising candidates for drug development. This article reviews groups of bioactive compounds that have been isolated and reported from the southern reaches of the Arctic Circle, surveys the known sponge diversity present in the Arctic waters, and details a recent sponge collection by our group in the Aleutian Islands, Alaska. The collection has yielded previously undescribed sponge species along with primary activity against opportunistic infectious diseases, malaria, and HCV. The discovery of new sponge species and bioactive crude extracts gives optimism for the isolation of new bioactive compounds from a relatively unexplored source.

Samuel Abbas; Michelle Kelly; John Bowling; James Sims; A Waters; Mark Hamann

2011-01-01T23:59:59.000Z

351

Nonlinear threshold behavior during the loss of Arctic sea ice  

E-Print Network (OSTI)

In light of the rapid recent retreat of Arctic sea ice, a number of studies have discussed the possibility of a critical threshold (or "tipping point") beyond which the ice-albedo feedback causes the ice cover to melt away in an irreversible process. The focus has typically been centered on the annual minimum (September) ice cover, which is often seen as particularly susceptible to destabilization by the ice-albedo feedback. Here we examine the central physical processes associated with the transition from ice-covered to ice-free Arctic Ocean conditions. We show that while the ice-albedo feedback promotes the existence of multiple ice cover states, the stabilizing thermodynamic effects of sea ice mitigate this when the Arctic Ocean is ice-covered during a sufficiently large fraction of the year. These results suggest that critical threshold behavior is unlikely during the approach from current perennial sea ice conditions to seasonally ice-free conditions. In a further warmed climate, however, we find that a ...

Eisenman, I; 10.1073/pnas.0806887106

2008-01-01T23:59:59.000Z

352

Stable isotopes in benthic foraminiferal calcite from a river-influenced Arctic marine environment, Kara and Pechora Seas  

E-Print Network (OSTI)

the World Ocean [e.g., Aagard and Car- mack, 1994]. During glacial periods, the Arctic hydro- graphic

Howat, Ian M.

353

Emergence of Fusion/Fission Cycling and Self-Organized Criticality from a Simulation Model of Early Complex Polities  

E-Print Network (OSTI)

Stanish, Charles, 2007. An Agent-based Model of Prehistoriccase of spatial agent- based models) that simulates wild

Griffin, Arthur F

2011-01-01T23:59:59.000Z

354

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

SciTech Connect

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.

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

2005-03-18T23:59:59.000Z

355

Do Changes in the Midlatitude Circulation Have Any Impact on the Arctic Surface Air Temperature Trend?  

Science Conference Proceedings (OSTI)

The warming of the near-surface air in the Arctic region has been larger than the global mean surface warming. There is general agreement that the Arctic amplification of the surface air temperature (SAT) trend to a considerable extent is due to ...

R. G. Graversen

2006-10-01T23:59:59.000Z

356

Low-Level Temperature Inversions of the Eurasian Arctic and Comparisons with Soviet Drifting Station Data  

Science Conference Proceedings (OSTI)

Seasonal and regional variations in characteristics of the Arctic low-level temperature inversion are examined using up to 12 years of twice-daily rawinsonde data from 31 inland and coastal sites of the Eurasian Arctic and a total of nearly six ...

Mark C. Serreze; Russell C. Schnell; Jonathan D. Kahl

1992-06-01T23:59:59.000Z

357

TOWARDS A CHARACTERIZATION OF ARCTIC MIXED-PHASE CLOUDS CIRES/NOAA/ETL  

E-Print Network (OSTI)

, radar-based retrieval methods. On average, mixed-phase cloud ice particle mean diameters increase fromTOWARDS A CHARACTERIZATION OF ARCTIC MIXED-PHASE CLOUDS Shupe, M. CIRES/NOAA/ETL Kollias, P Laboratory P.O. Box, Upton, NY www.bnl.gov ABSTRACT Mixed-phase clouds play a unique role in the Arctic

358

Fluctuations and seasonality in the Arctic sea ice area: A sudden regime shift in 2007?  

E-Print Network (OSTI)

Since the beginning of satellite observations, the Arctic sea ice extent has shown a downward trend. The decline has been weaker in the March maximum than in the September minimum and masked by inter-annual fluctuations. One of the less understood aspects of the sea ice response is the persistence times for fluctuations, which could indicate the dominant physical processes behind the sea ice decline. To determine the fluctuation persistence times, however, it is necessary to first filter out the dominant effect of the seasonal cycle. In the current study, we thus develop a statistical model, which accurately decomposes the ice area changes into: (1) a variable seasonal cycle component with a constant shape and (2) a residual (short term) fluctuation. We find the persistence time of fluctuations to be only about three weeks, independently from season, which is substantially shorter than previously reported. Such short time scale points to the dominance of atmospheric forcing. The shape of the seasonal cycle is surprisingly constant for the whole observational record despite the rapid decline. This is in agreement with the suggestion that the asymmetry of the seasonal cycle is an effect of Arctic land-sea geography, which has not changed with climate change. The analysis suggest a jump in the annual sea ice area amplitude occurring in 2007, from which it has not yet recovered, possibly revealing a permanent amplitude shift. In physical sense, this could imply a shift towards the younger, thinner and more susceptible ice cover commencing after the immense 2007 multi-year ice loss.

Peter D. Ditlevsen; Ivana Cvijanovic

2013-08-22T23:59:59.000Z

359

Simulations of Arctic Mixed-Phase Clouds in Forecasts with CAM3 and AM2 for M-PACE  

SciTech Connect

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.

Xie, Shaocheng; Boyle, James; Klein, Stephen A.; Liu, Xiaohong; Ghan, Steven J.

2008-02-29T23:59:59.000Z

360

The 2004 North Slope of Alaska Arctic Winter Radiometric Experiment  

NLE Websites -- All DOE Office Websites (Extended Search)

2004 North Slope of Alaska 2004 North Slope of Alaska Arctic Winter Radiometric Experiment E. R. Westwater, M. A. Klein, and V. Leuski Cooperative Institute for Research in Environmental Sciences University of Colorado National Oceanic and Atmospheric Administration Environmental Technology Laboratory Boulder, Colorado A. J. Gasiewski, T. Uttal, and D. A. Hazen National Oceanic and Atmospheric Administration Environmental Technology Laboratory Boulder, Colorado D. Cimini Remote Sensing Division, CETEMPS Universita' dell'Aquila L'Aquila, Italy V. Mattioli Dipartimento di Ingegneria Elettronica e dell'Informazione Perugia, Italy B. L. Weber and S. Dowlatshahi Science Technology Corporation Boulder, Colorado J. A. Shaw Department of Electrical and Computer Engineering

Note: This page contains sample records for the topic "modeling complex arctic" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


361

Oil production in the Arctic Natl. Wildlife Refuge  

Science Conference Proceedings (OSTI)

This assessment responds to U.S. House and Senate committee requests for an examination of technical issues concerning potential development of the Arctic Natl. Wildlife Refuge (ANWAR) in northeastern Alaska. The illustrated report presents the results of an assessment of oilfield technology used to develop the Alaskan North Slope, as an analog for technology at ANWR. The report considers prospects for future North Slope oil production, especially the likelihood that oil flowing through the Trans Alaskan Pipeline System will decline dramatically during the next decade.

Not Available

1988-01-01T23:59:59.000Z

362

Formulation and Evaluation of Fast Dissolving Tablet of a Model Anti-Diabetic Drug By Inclusion Complexation Using Beta  

E-Print Network (OSTI)

In the present investigation an attempt was made to formulate fast dissolving tablets using BCS class II drug Repaglinide, ie low solubility and high permeability to form an inclusion complex to improve the dissolution rate, thus enhancing the bioavailability. Beta-CD inclusion complex was made in varying ratios 1:1, 1:3 and 1:5 of drug and polymer by solvent evaporation method. The complexes were evaluated for phase solubility, drug content and drug release. Phase solubility study revealed AL type indicating linear increase in solubility with increase in the carrier concentrations. The inclusion complex 1:1 ratio prepared by spray dried was studied for drug content uniformity which was ranging from 85-98%, FTIR showed no any compatibility of the drug and beta-CD; DSC and XRD showed distinct loss of drug crystallinity accounting for enhancement in the dissolution rate. SEM revealed spherical shape of the inclusion complex. The drug release study was carried out in 0.1N HCL using USP type paddle dissolution apparatus revealed to be 93 % within 5 mins. The FDT was formulated by direct compression method six batches of tablets were prepared with varying ratios of superdisintegrants (F1-F6). The tablets were evaluated for hardness, friability, weight variation, disintegration which was found within

Mahalingan K; Ganesh R. S; Ronak Patel; Umashankar M. S

2012-01-01T23:59:59.000Z

363

Modeling of complex oxide materials from the first principles: systematic applications to vanadates RVO3 with distorted perovskite structure  

Science Conference Proceedings (OSTI)

"Realistic modeling" is a new direction of electronic structure calculations, where the main emphasis is made on the construction of some effective low-energy model entirely within a first-principle framework. Ideally, it is a model in form, but with ... Keywords: Effective models, First-principle calculations, Perovskite vanadates, Spin-orbital order

Igor Solovyev

2011-06-01T23:59:59.000Z

364

A Micro-Grid Simulator Tool (SGridSim) using Effective Node-to-Node Complex Impedance (EN2NCI) Models  

SciTech Connect

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%.

Udhay Ravishankar; Milos manic

2013-08-01T23:59:59.000Z

365

On the Closure Problem in the Reduction of Complex Atmospheric Models by PIPs and EOFs: A Comparison for the Case of a Two-Layer Model with Zonally Symmetric Forcing  

Science Conference Proceedings (OSTI)

The reduction of complex systems to their essential degrees of freedom (e.g., patterns spanning that part of state space that the system’s trajectory passes in time) and development of reduced models based on these might be one tool for improving ...

U. Achatz; G. Schmitz

1997-10-01T23:59:59.000Z

366

Model and solution for the multilevel production-inventory system before ironmaking in shanghai baoshan iron and steel complex  

Science Conference Proceedings (OSTI)

This research deals with the production-inventory problem originating from the ironmaking production system in Shanghai Baoshan Iron and Steel Complex (Baosteel). To solve this multilevel, multi-item, multi-period, capacitated lot-sizing problem, a deterministic ... Keywords: combinatorial optimization, lagrangian relaxation, lot-sizing

Guoli Liu; Lixin Tang

2006-05-01T23:59:59.000Z

367

An integrated safety prognosis model for complex system based on dynamic Bayesian network and ant colony algorithm  

Science Conference Proceedings (OSTI)

In complex industrial system, most of single faults have multiple propagation paths, so any local slight deviation is able to propagate, spread, accumulate and increase through system fault causal chains. It will finally result in unplanned outages and ... Keywords: Ant colony algorithm, Dynamic Bayesian networks, Fault propagation path, Proactive maintenance, Risk evaluation, Safety prognosis

Jinqiu Hu; Laibin Zhang; Lin Ma; Wei Liang

2011-03-01T23:59:59.000Z

368

A systems-theoretic security model for large scale, complex systems applied to the US air transportation system  

E-Print Network (OSTI)

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 ...

Laracy, Joseph R. (Joseph Raymond)

2007-01-01T23:59:59.000Z

369

A Potential Role for Immersion Freezing in Arctic Mixed-Phase Stratus  

NLE Websites -- All DOE Office Websites (Extended Search)

Potential Role for Immersion Freezing in Arctic Mixed-Phase Stratus Potential Role for Immersion Freezing in Arctic Mixed-Phase Stratus Gijs de Boer, Edwin W. Eloranta, Tempei Hashino, and Gregory J. Tripoli The University of Wisconsin - Madison (1) Introduction Ice formation appears to a dominant factor controlling the lifecycle of Arctic mixed-phase clouds. To date, our understanding of ice formation in these long-lasting cloud structures does not explain the formation of observed ice amounts. Particularly puzzling are observa-

370

Arctic Energy Technology Development Laboratory (Part 2)  

DOE Green Energy (OSTI)

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.

See OSTI ID Number 960443

2008-12-31T23:59:59.000Z

371

Remote Monitoring of Freeze -Thaw Transitions in Arctic Soils using1 the Complex Resistivity Method2  

E-Print Network (OSTI)

) EDITORA¸C~AO ELETR^ONICA: Viveca Sant´Ana Lemos - Servi¸co de Informa¸c~ao e Documenta¸c~ao (SID) #12;INPE

Hubbard, Susan

372

Regional Variability of the Arctic Heat Budget in Fall and Winter  

Science Conference Proceedings (OSTI)

In the Arctic atmosphere, the fall cooling cycle involves the evolution of the zonally symmetric circulation in late summer into the asymmetric flow of winter. This paper uses historical reanalysis data to document how the dominant components of ...

Jennifer Miletta Adams; Nicholas A. Bond; James E. Overland

2000-10-01T23:59:59.000Z

373

Observed atmospheric response to cold season sea ice variability in the Arctic  

Science Conference Proceedings (OSTI)

The relation between weekly Arctic sea ice concentrations (SIC) from December to April and sea level pressure (SLP) during 1979-2007 is investigated using Maximum Covariance Analysis (MCA). In the North Atlantic sector, the interaction between the ...

Claude Frankignoul; Nathalie Sennéchael; Pierre Cauchy

374

An Observational Estimate of Volume and Freshwater Flux Leaving the Arctic Ocean through Nares Strait  

Science Conference Proceedings (OSTI)

The Arctic Ocean is an important link in the global hydrological cycle, storing freshwater and releasing it to the North Atlantic Ocean in a variable fashion as pack ice and freshened seawater. An unknown fraction of this return flow passes ...

Andreas Münchow; Humfrey Melling; Kelly K. Falkner

2006-11-01T23:59:59.000Z

375

Climatology and Interannual Variability of Arctic Cyclone Activity: 1948–2002  

Science Conference Proceedings (OSTI)

Arctic cyclone activity is investigated in the context of climate change and variability by using a modified automated cyclone identification and tracking algorithm, which differs from previously used algorithms by single counting each cyclone. ...

Xiangdong Zhang; John E. Walsh; Jing Zhang; Uma S. Bhatt; Moto Ikeda

2004-06-01T23:59:59.000Z

376

Energy Policy 35 (2007) 47204729 Should we drill in the Arctic National Wildlife Refuge?  

E-Print Network (OSTI)

information and provides original analysis. We apEnergy Policy 35 (2007) 4720­4729 Should we drill in the Arctic National Wildlife Refuge $123 billion to extract and bring to market. The difference, $251 billion, would generate social

Kotchen, Matthew J.

377

Potential Oil Production from the Coastal Plain of the Arctic National  

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

Potential Oil Production from the Coastal Plain of the Arctic National Wildlife Refuge: Updated Assessment Potential Oil Production from the Coastal Plain of the Arctic National Wildlife Refuge: Updated Assessment References Energy Information Administration, Annual Energy Outlook 2000, DOE/EIA-0383(2000) (Washington, DC, December 1999), Table A11. Energy Information Administration, Potential Oil Production from the Coastal Plain of the Arctic National Wildlife Refuge, SR/RNGD/87-01 (Washington, DC, September 1987). U.S. Department of Interior, Arctic National Wildlife Refuge, Alaska, Coastal Plain Resource Assessment, (Washington, DC, November, 1986). U.S. Department of Interior, Bureau of Land Management, Minerals Management Service. Northeast National Petroleum Reserve-Alaska Final Integrated Activity Plan / Environmental Impact Statement, (Anchorage , Alaska, August, 1998).

378

Variations in Surface Air Temperatures: Part 2. Arctic Regions, 1881–1980  

Science Conference Proceedings (OSTI)

We describe annual and seasonal changes in air temperatures over high latitudes of the Northern Hemisphere during the period 1881–1980. Trends (that is, fluctuations on time scales greater than 20 years) in the average temperature of the Arctic ...

P. M. Kelly; P. D. Jones; C. B. Sear; B. S. G. Cherry; R. K. Tavakol

1982-02-01T23:59:59.000Z

379

Arctic Cloud Microphysics Retrievals from Surface-Based Remote Sensors at SHEBA  

Science Conference Proceedings (OSTI)

An operational suite of ground-based, remote sensing retrievals for producing cloud microphysical properties is described, assessed, and applied to 1 yr of observations in the Arctic. All measurements were made in support of the Surface Heat ...

Matthew D. Shupe; Taneil Uttal; Sergey Y. Matrosov

2005-10-01T23:59:59.000Z

380

An Empirical Blowing Snow Forecast Technique for the Canadian Arctic and the Prairie Provinces  

Science Conference Proceedings (OSTI)

Blowing snow has a major impact on transportation and public safety. The goal of this study is to provide an operational technique for forecasting high-impact blowing snow on the Canadian arctic and the Prairie provinces using historical ...

David G. Baggaley; John M. Hanesiak

2005-02-01T23:59:59.000Z

Note: This page contains sample records for the topic "modeling complex arctic" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


381

Satellite-Derived Surface Energy Balance Estimates in the Alaskan Sub-Arctic  

Science Conference Proceedings (OSTI)

Heat Capacity Mapping Mission (HCMM) data for 12 May 1978 were used in an energy balance modelto estimate evapotranspiration in sub-Arctic Alaska following snowmelt. The HCMM scene contained severalareas of melting snow as well as an actively ...

R. J. Gurney; D. K. Hall

1983-01-01T23:59:59.000Z

382

Satellite Retrievals of Arctic and Equatorial Rain and Snowfall Rates Using Millimeter Wavelengths  

E-Print Network (OSTI)

A new global precipitation retrieval algorithm for the millimeter-wave Advanced Microwave Sounding Unit is presented that also retrieves Arctic precipitation rates over surface snow and ice. This algorithm improves upon ...

Surussavadee, Chinnawat

383

A Thermodynamic Analysis of an Intense North American Arctic Air Mass  

Science Conference Proceedings (OSTI)

Northwestern Canada is a genesis region of arctic air masses often considered to be formed primarily through radiative processes. However, the details of their life cycle are poorly understood. This paper examines the formation, maintenance, and ...

Jessica K. Turner; John Gyakum; Shawn M. Milrad

2013-01-01T23:59:59.000Z

384

The Uses and Limitations of Contour Advection as a Technique for Examining Arctic Vortex Dynamics  

Science Conference Proceedings (OSTI)

A contour advection technique, contour advection with surgery (CAS), is applied to the Northern Hemisphere Arctic vortex during several dynamically active periods in midwinter and at several different levels in the stratosphere. The ability of ...

Michael N. Baker; Derek M. Cunnold

2001-08-01T23:59:59.000Z

385

Surface Albedo over the Arctic Ocean Derived from AVHRR and Its Validation with SHEBA Data  

Science Conference Proceedings (OSTI)

A method is presented for retrieving the broadband albedo over the Arctic Ocean using advanced very high resolution radiometer (AVHRR) data obtained from NOAA polar-orbiting satellites. Visible and near-infrared albedos over snow and ice surfaces ...

Xiaozhen Xiong; Knut Stamnes; Dan Lubin

2002-04-01T23:59:59.000Z

386

On the Relationship between Thermodynamic Structure and Cloud Top, and Its Climate Significance in the Arctic  

Science Conference Proceedings (OSTI)

Cloud and thermodynamic characteristics from three Arctic observation sites are investigated to understand the collocation between low-level clouds and temperature inversions. A regime where cloud top was 100–200 m above the inversion base [cloud ...

Joseph Sedlar; Matthew D. Shupe; Michael Tjernström

2012-04-01T23:59:59.000Z

387

Climate Change and Cultural Survival in the Arctic: People of the Whales and Muktuk Politics  

Science Conference Proceedings (OSTI)

This article explores the interface of climate change and society in a circumpolar context, particularly experienced among the Iñupiaq people (Iñupiat) of Arctic Alaska. The Iñupiat call themselves the “People of the Whales,” and their physical ...

Chie Sakakibara

2011-04-01T23:59:59.000Z

388

Using A-Train Arctic cloud observations to constrain and improve...  

NLE Websites -- All DOE Office Websites (Extended Search)

radiation anomalies to the 2007 Arctic sea ice loss Jennifer E. Kay 1,2 Andrew Gettelman 1 , Tristan L'Ecuyer 2 ,Graeme Stephens 2 , and Chris O'Dell 2 1 National Center for...

389

Short-lived pollutants in the Arctic: their climate impact and possible mitigation strategies  

E-Print Network (OSTI)

reduced rate of ice formation in mixed- phase Arctic cloudsincreases occur in phase with sea ice melt, potentiallyIce properties of single-layer stratocumulus during the Mixed-Phase

Quinn, P.K.

2008-01-01T23:59:59.000Z

390

Temporal Variability in the Expression of the Arctic Oscillation in the North Pacific  

Science Conference Proceedings (OSTI)

Although the Arctic Oscillation (AO) and North Atlantic Oscillation (NAO) have been identified as important modes of climate variability during the Northern Hemisphere (NH) winter, whether the AO or the NAO is more fundamental to the description ...

Hongxu Zhao; G. W. K. Moore

2009-06-01T23:59:59.000Z

391

Instrumentation to Measure the Depth/Time Fluctuations in Acoustic Pulses Propagated through Arctic Internal Waves  

Science Conference Proceedings (OSTI)

Instrumentation for measuring the evolution of volume-scattered acoustic signals in both depth and time is described. Measurements were taken for 12 days during the spring of 1985 with transmitters and receivers suspended beneath arctic pack ice ...

Terry E. Ewart; Stephen A. Reynolds

1990-02-01T23:59:59.000Z

392

Potential Impacts of the Arctic on Interannual and Interdecadal Summer Precipitation over China  

Science Conference Proceedings (OSTI)

After the end of the 1970s, there has been a tendency for enhanced summer precipitation over south China and the Yangtze River valley and drought over north China and northeastern China. Coincidentally, Arctic ice concentration has decreased since ...

Yuefeng Li; L. Ruby Leung

2013-02-01T23:59:59.000Z

393

Observational and Theoretical Studies of Solar Radiation in Arctic Stratus Clouds  

Science Conference Proceedings (OSTI)

A series of clouds-radiation experiments was carried out in June 1980 in Arctic stratus clouds occurring over the Beaufort Sea using the NCAR Electra aircraft. This paper is an analysis of the hemispheric radiation fields obtained with Eppley ...

G. F. Herman; J. A. Curry

1984-01-01T23:59:59.000Z

394

Simulated Response of the Arctic Freshwater Budget to Extreme NAO Wind Forcing  

Science Conference Proceedings (OSTI)

The authors investigate the response of the Arctic Ocean freshwater budget to changes in the North Atlantic Oscillation (NAO) using a regional-ocean configuration of the Massachusetts Institute of Technology GCM (MITgcm) and carry out several ...

Alan Condron; Peter Winsor; Chris Hill; Dimitris Menemenlis

2009-05-01T23:59:59.000Z

395

Variations in Surface Air Temperature Observations in the Arctic, 1979–97  

Science Conference Proceedings (OSTI)

The statistics of surface air temperature observations obtained from buoys, manned drifting stations, and meteorological land stations in the Arctic during 1979–97 are analyzed. Although the basic statistics agree with what has been published in ...

Ignatius G. Rigor; Roger L. Colony; Seelye Martin

2000-03-01T23:59:59.000Z

396

Seasonal and Regional Variation of Pan-Arctic Surface Air Temperature over the Instrumental Record  

Science Conference Proceedings (OSTI)

Instrumental surface air temperature (SAT) records beginning in the late 1800s from 59 Arctic stations north of 64°N show monthly mean anomalies of several degrees and large spatial teleconnectivity, yet there are systematic seasonal and regional ...

James E. Overland; Michael C. Spillane; Donald B. Percival; Muyin Wang; Harold O. Mofjeld

2004-09-01T23:59:59.000Z

397

The Development of Arctic Air Masses in Northwest Canada and Their Behavior in a Warming Climate  

Science Conference Proceedings (OSTI)

Surface observations, soundings, and a thermodynamic budget are used to investigate the formation process of 93 arctic airmass events. The events involve very cold surface temperatures—an average of ?42.8°C at Norman Wells, a centrally located ...

Jessica K. Turner; John R. Gyakum

2011-09-01T23:59:59.000Z

398

Influence of Humidified Aerosol on Lidar Depolarization Measurements below Ice-Precipitating Arctic Stratus  

Science Conference Proceedings (OSTI)

Lidar measurements obtained during the Surface Heat Budget of the Arctic Ocean (SHEBA) experiment under a mixed-phase stratus cloud that was lightly precipitating ice show a range of surprisingly low depolarization ratios (4%–23%), despite an ...

Bastiaan van Diedenhoven; Ann M. Fridlind; Andrew S. Ackerman

2011-10-01T23:59:59.000Z

399

Clouds at Arctic Atmospheric Observatories. Part I: Occurrence and Macrophysical Properties  

Science Conference Proceedings (OSTI)

Cloud observations over the past decade from six Arctic atmospheric observatories are investigated to derive estimates of cloud occurrence fraction, vertical distribution, persistence in time, diurnal cycle, and boundary statistics. Each ...

Matthew D. Shupe; Von P. Walden; Edwin Eloranta; Taneil Uttal; James R. Campbell; Sandra M. Starkweather; Masataka Shiobara

2011-03-01T23:59:59.000Z

400

Observed Relationships between Arctic Longwave Cloud Forcing and Cloud Parameters Using a Neural Network  

Science Conference Proceedings (OSTI)

A neural network technique is used to quantify relationships involved in cloud–radiation feedbacks based on observations from the Surface Heat Budget of the Arctic (SHEBA) project. Sensitivities of longwave cloud forcing (CFL) to cloud parameters ...

Yonghua Chen; Filipe Aires; Jennifer A. Francis; James R. Miller

2006-08-01T23:59:59.000Z

Note: This page contains sample records for the topic "modeling complex arctic" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


401

Deep-Water Flow over the Lomonosov Ridge in the Arctic Ocean  

Science Conference Proceedings (OSTI)

The Arctic Ocean likely impacts global climate through its effect on the rate of deep-water formation and the subsequent influence on global thermohaline circulation. Here, the renewal of the deep waters in the isolated Canadian Basin is ...

M-L. Timmermans; P. Winsor; J. A. Whitehead

2005-08-01T23:59:59.000Z

402

Abstract--Modelling and control of gas turbines (GTs) have always been a controversial issue because of the complex  

E-Print Network (OSTI)

Abstract--Modelling and control of gas turbines (GTs) have always been a controversial issue that there is no end to the efforts for performance optimization of gas turbines. A variety of analytical and experimental models as well as control systems has been built so far for gas turbines. However, the need

Sainudiin, Raazesh

403

Research article: Monte Carlo-based rigid body modelling of large protein complexes against small angle scattering data  

Science Conference Proceedings (OSTI)

We present a modular, collaborative, open-source architecture for rigid body modelling based upon small angle scattering data, named sas_rigid. It is designed to provide a fast and extensible scripting interface using the easy-to-learn Python programming ... Keywords: Hemocyanin, Monte Carlo with simulated annealing, Rigid body modelling, Small angle scattering (SAS)

Christian Meesters; Bruno Pairet; Anja Rabenhorst; Heinz Decker; Elmar Jaenicke

2010-06-01T23:59:59.000Z

404

Energy Design Guidelines for High Performance Schools: Arctic and Subarctic Climates  

Science Conference Proceedings (OSTI)

The Energy Design Guidelines for High Performance Schools--Arctic and Subarctic Climates provides school boards, administrators, and design staff with guidance to help them make informed decisions about energy and environmental issues important to school systems and communities. These design guidelines outline high performance principles for the new or retrofit design of your K-12 school in arctic and subarctic climates. By incorporating energy improvements into their construction or renovation plans, schools can significantly reduce energy consumption and costs.

Not Available

2004-11-01T23:59:59.000Z

405

The Influence of Artificial and Physical Factors upon Predictability Estimates Using a Complex Limited-Area Model  

Science Conference Proceedings (OSTI)

Recently, optimistic reports have appeared indicating that mesoscale circulations are more predictable than synoptic scale circulations. These have been based on studies using limited-area meso-?-scale forecast models. Warnings have also appeared ...

Tomislava Vukicevic; Ronald M. Errico

1990-07-01T23:59:59.000Z

406

Evaluation of Turbulence Closure Models for Large-Eddy Simulation over Complex Terrain: Flow over Askervein Hill  

Science Conference Proceedings (OSTI)

The evaluation of turbulence closure models for large-eddy simulation (LES) has primarily been performed over flat terrain, where comparisons with theory and observations are simplified. The authors have previously developed improved closure ...

Fotini Katopodes Chow; Robert L. Street

2009-05-01T23:59:59.000Z

407

Renewable Resources: a national catalog of model projects. Volume 2. Mid-American Solar Energy Complex Region  

DOE Green Energy (OSTI)

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)

None

1980-07-01T23:59:59.000Z

408

Recent Greenland Accumulation Estimated from Regional Climate Model Simulations and Ice Core Analysis  

Science Conference Proceedings (OSTI)

The accumulation defined as “precipitation minus evaporation” over Greenland has been simulated with the high-resolution limited-area regional climate model HIRHAM4 applied over an Arctic integration domain. This simulation is compared with a ...

K. Dethloff; M. Schwager; J. H. Christensen; S. Kiilsholm; A. Rinke; W. Dorn; F. Jung-Rothenhäusler; H. Fischer; S. Kipfstuhl; H. Miller

2002-10-01T23:59:59.000Z

409

Mercury uptake and dynamics in sea ice algae, phytoplankton and grazing copepods from a Beaufort Sea Arctic marine food web.  

E-Print Network (OSTI)

??Mercury (Hg) is one of the primary contaminants of concern in the Arctic marine ecosystem. Methyl Hg (MeHg) is known to biomagnify in food webs.… (more)

Burt, Alexis Emelia

2012-01-01T23:59:59.000Z

410

Use of GIS and 3D Modeling for Development and Conceptualization of a Performance Assessment Model for Decommissioning of a Complex Site  

Science Conference Proceedings (OSTI)

Geographic Information Systems (GIS) and 3D geo-spatial modeling were employed to facilitate development and conceptualization of a performance assessment (PA) model that will be used to evaluate the health impacts of residual radioactivity at a former nuclear materials processing facility site in New York. Previous operations have resulted in a number of different sources of radiological contamination that must be assessed during site decommissioning. A performance assessment model is being developed to estimate radiological dose to potential receptors through the simulation of the release and transport of radionuclides, and exposure to residual contamination for hundreds to thousands of years in the future. A variety of inputs are required to parameterize the performance assessment model, such as: distance from the waste to surface water bodies, thickness of geologic units for saturated transport, saturated thickness of the geologic units, and spatial and temporal average of percent of waste that is saturated. GIS and 3D modeling are used to analyze and abstract aleatory uncertainty associated with the dimensionality of the geologic system into epistemic uncertainty for one- and two-dimensional process models for flow and transport of radionuclides. Three-dimensional geo-spatial modeling was used to develop the geologic framework and the geometrical representation of the residual contamination within the geologic framework. GIS was used in the initial development and parameterization of the transport pathways, to provide spatial context to the PA model, and to link it to the 3D geologic framework and contamination geometry models. Both the GIS and 3-D modeling were used to interpret the results of runs of the PA model. (authors)

Esh, D. W.; Gross, A. J.; Thaggard, M. [U.S. Nuclear Regulatory Commission, Two White Flint North, MS T7J8, 11545 Rockville Pike, Rockville, MD 20852 (United States)

2006-07-01T23:59:59.000Z

411

Automating calibration, sensitivity and uncertainty analysis of complex models using the R package Flexible Modeling Environment (FME): SWAT as an example  

Science Conference Proceedings (OSTI)

Parameter optimization and uncertainty issues are a great challenge for the application of large environmental models like the Soil and Water Assessment Tool (SWAT), which is a physically-based hydrological model for simulating water and nutrient cycles ... Keywords: Calibration, FME, Monte Carlo, R, SWAT, Sensitivity and uncertainty analysis

Yiping Wu; Shuguang Liu

2012-05-01T23:59:59.000Z

412

Lyapunov exponent for inertial particles in the 2D Kraichnan model as a problem of Anderson localization with complex valued potential  

E-Print Network (OSTI)

We exploit the analogy between dynamics of inertial particle pair separation in a random-in-time flow and the Anderson model of a quantum particle on the line in a spatially random real-valued potential. Thereby we get an exact formula for the Lyapunov exponent of pair separation in a special case, and we are able to generalize the class of solvable models slightly, for potentials that are real up to a global complex multiplier. A further important result for inertial particle behavior, supported by analytical computations in some cases and by numerics more generally, is that of the decay of the Lyapunov exponent with large Stokes number (quotient of particle relaxation and flow turn-over time-scales) as Stokes number to the power -2/3.

Peter Horvai

2005-11-14T23:59:59.000Z

413

Evaluation of Mixed-Phase Cloud Parameterizations in Short-Range Weather Forecasts with CAM3 and AM2 for Mixed-Phase Arctic Cloud Experiment  

SciTech Connect

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.

Xie, S; Boyle, J; Klein, S; Liu, X; Ghan, S

2007-06-01T23:59:59.000Z

414

Energy variational analysis of ions in water and channels: Field theory for primitive models of complex ionic fluids  

E-Print Network (OSTI)

Energy variational analysis of ions in water and channels: Field theory for primitive models EnVarA energy variational analysis that combines Hamilton's least action and Rayleigh's dissipation, and ion channels. Flows are driven by a combination of electrical and chemical potentials that depend

Liu, Chun

415

3D modeling of large and complex site using multi-sensor integration and multi-resolution data  

Science Conference Proceedings (OSTI)

The article describes a multi-resolution approach developed for the 3D modeling of the entire Roman Forum in Pompeii, Italy. The archaeological area, approximately 150 x 80 m, contains more than 350 finds spread all over the Forum as well as larger mural ...

Gabriele Guidi; Fabio Remondino; Michele Russo; Fabio Menna; Alessandro Rizzi

2008-12-01T23:59:59.000Z

416

Concept Study: Exploration and Production in Environmentally Sensitive Arctic Areas  

Science Conference Proceedings (OSTI)

The Alaska North Slope offers one of the best prospects for increasing U.S. domestic oil and gas production. However, this region faces some of the greatest environmental and logistical challenges to oil and gas production in the world. A number of studies have shown that weather patterns in this region are warming, and the number of days the tundra surface is adequately frozen for tundra travel each year has declined. Operators are not allowed to explore in undeveloped areas until the tundra is sufficiently frozen and adequate snow cover is present. Spring breakup then forces rapid evacuation of the area prior to snowmelt. Using the best available methods, exploration in remote arctic areas can take up to three years to identify a commercial discovery, and then years to build the infrastructure to develop and produce. This makes new exploration costly. It also increases the costs of maintaining field infrastructure, pipeline inspections, and environmental restoration efforts. New technologies are needed, or oil and gas resources may never be developed outside limited exploration stepouts from existing infrastructure. Industry has identified certain low-impact technologies suitable for operations, and has made improvements to reduce the footprint and impact on the environment. Additional improvements are needed for exploration and economic field development and end-of-field restoration. One operator-Anadarko Petroleum Corporation-built a prototype platform for drilling wells in the Arctic that is elevated, modular, and mobile. The system was tested while drilling one of the first hydrate exploration wells in Alaska during 2003-2004. This technology was identified as a potentially enabling technology by the ongoing Joint Industry Program (JIP) Environmentally Friendly Drilling (EFD) program. The EFD is headed by Texas A&M University and the Houston Advanced Research Center (HARC), and is co-funded by the National Energy Technology Laboratory (NETL). The EFD participants believe that the platform concept could have far-reaching applications in the Arctic as a drilling and production platform, as originally intended, and as a possible staging area. The overall objective of this project was to document various potential applications, locations, and conceptual designs for the inland platform serving oil and gas operations on the Alaska North Slope. The University of Alaska Fairbanks assisted the HARC/TerraPlatforms team with the characterization of potential resource areas, geotechnical conditions associated with continuous permafrost terrain, and the potential end-user evaluation process. The team discussed the various potential applications with industry, governmental agencies, and environmental organizations. The benefits and concerns associated with industry's use of the technology were identified. In this discussion process, meetings were held with five operating companies (22 people), including asset team leaders, drilling managers, HSE managers, and production and completion managers. Three other operating companies and two service companies were contacted by phone to discuss the project. A questionnaire was distributed and responses were provided, which will be included in the report. Meetings were also held with State of Alaska Department of Natural Resources officials and U.S. Bureau of Land Management regulators. The companies met with included ConcoPhillips, Chevron, Pioneer Natural Resources, Fairweather E&P, BP America, and the Alaska Oil and Gas Association.

Shirish Patil; Rich Haut; Tom Williams; Yuri Shur; Mikhail Kanevskiy; Cathy Hanks; Michael Lilly

2008-12-31T23:59:59.000Z

417

Final Technical Report: Development of the DUSTRAN GIS-Based Complex Terrain Model for Atmospheric Dust Dispersion  

SciTech Connect

Activities at U.S. Department of Defense (DoD) training and testing ranges can be sources of dust in local and regional airsheds governed by air-quality regulations. The U.S. Department of Energy’s Pacific Northwest National Laboratory just completed a multi-year project to develop a fully tested and documented atmospheric dispersion modeling system (DUST TRANsport or DUSTRAN) to assist the DoD in addressing particulate air-quality issues at military training and testing ranges.

Allwine, K Jerry; Rutz, Frederick C.; Shaw, William J.; Rishel, Jeremy P.; Fritz, Brad G.; Chapman, Elaine G.; Hoopes, Bonnie L.; Seiple, Timothy E.

2007-05-01T23:59:59.000Z

418

Petroleum geochemistry of oils and rocks in Arctic National Wildlife Refuge, Alaska  

Science Conference Proceedings (OSTI)

Thirteen oil seeps or oil-stained outcrops in or adjacent to the coastal plain of the Arctic National Wildlife Refuge (ANWR) in northeastern Alaska indicate that commercial quantities of hydrocarbons may be present in the subsurface. The area is flanked by two important petroleum provinces: the Prudhoe Bay area on the west and the Mackenzie delta on the east. Organic carbon content (wt. %), organic matter type, and pyrolysis hydrocarbon yield show that rock units such as the Kingak Shale (average 1.3 wt. %), pebble shale unit (2.1 wt. %), and Canning Formation (1.9 wt. %) contain predominantly type III organic matter. The exception is the Hue Shale (5.9 wt. %), which contains type II organic matter. Pre-Cretaceous rocks that crop out in the Brooks Range could not be adequately evaluated because of high thermal maturity. Thermal maturity thresholds for oil, condensate, and gas calculated from vitrinite reflectance gradients in the Point Thomson area are 4000, 7300, and 9330 m, respectively (12,000, 22,500, and 28,000 ft). Time-temperature index (TTI) calculations for the Beli-1 and Point Thomson-1 wells immediately west of ANWR indicate that maturity first occurred in the south and progressed north. The Cretaceous Hue Shale matured in the Beli-1 well during the Eocene and in the Point Thomson-1 well in the late Miocene to early Pliocene. In the Point Thomson area, the condensate and gas recovered from the Thomson sandstone and basement complex based on API gravity and gas/oil ratio (GOR) probably originated from the pebble shale unit, and on the same basis, the oil recovered from the Canning Formation probably originated from the Hue Shale. The gas recovered from the three wells in the Kavik area is probably thermal gas from overmature source rocks in the immediate area.

Magoon, L.B.; Anders, D.E.

1987-05-01T23:59:59.000Z

419

Concept of the transport system in the western part of the Arctic  

Science Conference Proceedings (OSTI)

According to the concept of the energy policy of Russia under new economic conditions, the production of oil and gas condensate after a decline to 300-345 million tons/yr in 1997 will reach 370-400 million tons in 2010, and the export of oil and petroleum products, apart from countries of the CIS, will be 90-120 million tons/yr and of natural gas 130-140 billion m{sup 3}. The main sources of oil and gas production will be Volga region and Tyumen, Yamal, and Pechora-Nenets provinces. The most prospective oil and gas fields are located in an extensive territory north of the Arctic Circle and on the continental shelf of the Barnets and Kara Seas. The geographic location of the world`s richest fields of energy resources creates favorable conditions for their export to Northern Europe, northern states of the USA and Canada, and after developing direct sailing along the Northern Sea Route. According to preliminary data, the volume of export of oil and petroleum products in the next 10-15 years form this region can amount to 20-25 millions tons and delivery of supplies 1.5-2.0 million tons. Sea transport plays a substantial role in export shipments. In 1989, 98.0 Million tons of oil was unloaded through Black Sea and Baltic ports. The transport system should be reliable, ecologically safe, and cost-effective, should adapt well for providing the fields being developed on the continent and shelf with transport services, and should deliver oil and products to any importing country. With consideration of the complex; and importance of the problem, in the present concept the transport system in the stretch of domestic traffic is examined in there variants: variant 1 - {open_quotes}Island terminal,{close_quotes} variant 2 - {open_quotes}Oil trunk pipeline,{close_quotes} 3 - {open_quotes}Shore terminal.{close_quotes}

Parfenov, A.F.

1994-09-01T23:59:59.000Z

420

One-Level Diagnostic Modeling of Mesoscale Surface Winds in Complex Terrain. Part I: Comparison with Three-Dimensional Modeling in Israel  

Science Conference Proceedings (OSTI)

A one-level sigma-coordinate model originally developed by Danard and modified by Mass and Dempsey and Alpert et al., is applied to the study of surface flow over an averaged summer diurnal cycle in Israel. The detailed flow features are compared ...

P. Alpert; B. Getenio

1988-10-01T23:59:59.000Z

Note: This page contains sample records for the topic "modeling complex arctic" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


421

Evolution of the Arctic Ocean Salinity, 2007–08: Contrast between the Canadian and the Eurasian Basins  

Science Conference Proceedings (OSTI)

The authors investigate the variability of salinity in the Arctic Ocean and in the Nordic and Labrador Seas over recent years to see how the freshwater balance in the Arctic and the exchanges with the North Atlantic have been affected by the ...

Camille Lique; Gilles Garric; Anne-Marie Treguier; Bernard Barnier; Nicolas Ferry; Charles-Emmanuel Testut; Fanny Girard-Ardhuin

2011-03-01T23:59:59.000Z

422

Development of an Antarctic Regional Climate System Model. Part I: Sea Ice and Large-Scale Circulation  

Science Conference Proceedings (OSTI)

A coupled atmosphere–ice regional model previously used for simulations in the Arctic has been implemented in the Antarctic. Three 14-month simulations were performed for 1988–89, with different oceanic specifications. The year 1988 was ...

David A. Bailey; Amanda H. Lynch

2000-04-01T23:59:59.000Z

423

Modeling Linear Kinematic Features in Sea Ice  

Science Conference Proceedings (OSTI)

Sea ice deformation is localized in narrow zones of high strain rate that extend hundreds of kilometers, for example, across the Arctic Basin. This paper demonstrates that these failure zones may be modeled with a viscous–plastic sea ice model, ...

Jennifer K. Hutchings; Petra Heil; William D. Hibler III

2005-12-01T23:59:59.000Z

424

Reservoir quality studies, Arctic National Wildlife Refuge, Alaska  

Science Conference Proceedings (OSTI)

Reservoir quality studies are part of the reservoir management and resource assessment programs of the U.S. Bureau of Land Management in Alaska. Petrographic analyses have been carried out of samples collected from surface exposures in the Arctic National Wildlife Refuge (ANWR), Alaska, to evaluate surface materials as to their potential reservoir rock qualities in the subsurface. This entails characterization of relevant petrologic-petrophysical properties, integration with regional geological-geophysical relationships, and synthesis in terms of likely diagenetic, structural, and stratigraphic conditions in the subsurface. There is a paucity of relevant data in this region. Inferences must be predicated largely on general principles and known relationships elsewhere. A spectrum of lithologies were studied, representing a substantial portion of the regional stratigraphic column. In a number of cases, particularly among the pre-Brookian samples, the rocks appear to have low reservoir potential, based on their present high degree of diagenetic maturity. There is always the possibility - deemed somewhat unlikely here - of subsurface equivalents with more favorable characteristics, due to different original compositions, textures, and/or geologic histories. Brookian sandstones and conglomerates feature samples with fair-good reservoir characteristics, with prospects of being equally good or better in the subsurface. The samples studied suggest the likelihood of horizons with viable reservoir qualities in the subsurface within the ANWR region.

Mowatt, T.C.; Banet, A. (U.S. Bureau of Land Management, Anchorage, AK (United States))

1991-03-01T23:59:59.000Z

425

CFD [computational fluid dynamics] And Safety Factors. Computer modeling of complex processes needs old-fashioned experiments to stay in touch with reality.  

SciTech Connect

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.

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

426

A 22-Year Dataset of Surface Longwave Fluxes in the Arctic  

NLE Websites -- All DOE Office Websites (Extended Search)

22-Year Dataset of Surface Longwave Fluxes 22-Year Dataset of Surface Longwave Fluxes in the Arctic J. Francis and J. Secora Institute of Marine and Coastal Sciences Rutgers University New Brunswick, New Jersey Abstract Downwelling longwave fluxes (DLFs) over the Arctic surface have been generated from 22.5 years of radiances and retrievals from the TIROS (television and infrared observation satellite) operational vertical sounder (TOVS). The flux retrieval algorithm has been validated and improved using surface- based radiation and cloud observations from the Atmospheric Radiation Measurement (ARM) North Slope of Alaska (NSA) site in Barrow, Alaska, and from the Surface Heat Balance of the Arctic (SHEBA) field program (1997-98) in the Beaufort Sea. The DLF product is presented on a 100 x

427

A 20-Year Dataset of Downwelling Longwave Flux at the Arctic Surface from TOVS Satellite Data  

NLE Websites -- All DOE Office Websites (Extended Search)

20-Year Dataset of Downwelling Longwave Flux 20-Year Dataset of Downwelling Longwave Flux at the Arctic Surface from TOVS Satellite Data J. Francis Rutgers University New Brunswick, New Jersey A. Schweiger Polar Science Center University of Washington Seattle, Washington J. Key National Oceanic and Atmospheric Administration National Environmental Satellite, Data, and Information Service Madison, Wisconsin Introduction This paper summarizes the progress of a study under way to generate a 20-year dataset of surface downwelling longwave flux (DLF) retrievals from satellite data over the Arctic Ocean. We will produce daily fields between late 1979 and late 1998 on a grid with a spatial resolution of 100 km x 100 km 2 north of 60°N. Surface measurements from the Surface Heat Budget of the Arctic (SHEBA) and the

428

Potential Oil Production from the Coastal Plain of the Arctic National  

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

Potential Oil Production from the Coastal Plain of the Arctic National Wildlife Refuge: Updated Assessment Potential Oil Production from the Coastal Plain of the Arctic National Wildlife Refuge: Updated Assessment Glossary ANILCA: Alaska National Interest Lands Conservation Act ANS: Alaskan North 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 wells, region, etc. (usually expressed in barrels per day) EIA: Energy Information Administration MBbls: thousand barrels MMBbls: million barrels NPR-A: National Petroleum Reserve-Alaska Petroleum Play: A set of known or postulated petroleum accumulations sharing similar geologic, geographic, and temporal properties such as source rock, migration, pathway, timing, trapping mechanism, and hydrocarbon type

429

SCC: The Strategic Computing Complex  

NLE Websites -- All DOE Office Websites (Extended Search)

SCC: The Strategic Computing Complex SCC: The Strategic Computing Complex SCC: The Strategic Computing Complex The Strategic Computing Complex (SCC) is a secured supercomputing facility that supports the calculation, modeling, simulation, and visualization of complex nuclear weapons data in support of the Stockpile Stewardship Program. The 300,000-square-foot, vault-type building features an unobstructed 43,500-square-foot computer room, which is an open room about three-fourths the size of a football field. The Strategic Computing Complex (SCC) at the Los Alamos National Laboratory (LANL) is a secured supercomputing facility that supports the calculation, modeling, simulation, and visualization of complex nuclear weapons data in support of the Stockpile Stewardship Program. National Security

430

Conceptual Models for Migration of Key Groundwater Contaminants Through the Vadose Zone and Into the Upper Unconfined Aquifer Below the B-Complex  

Science Conference Proceedings (OSTI)

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.

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

431

Probing The Electronic Structure of the Di-iron Subsite of[Fe] -hydrogenase: A Photoelectron Spectroscopic Study of Fe(I)- Fe(I) Model Complexes  

Science Conference Proceedings (OSTI)

The electronic structures of a series of Fe(I)-Fe(I) model complexes of the di-iron subsite of[Fe]-hydrogenase,[(mu- PDT)Fe-2(CO)(4)(CN)(2)](2-) (1),[Fe- 2(CO)(4)(MeSCH2C(Me)(CH2S)(2))(CN)(2)](2-) (II),[Fe- 2(CO)(4)(PhCH2SCH2C(Me)-(CH2S)(2))(CN)(2)](2-) (III),[Fe- 2(CO)(4)(PhCH2SCH2C(Me) (CH2S)(2))(CN)](-) (IV), and[Fe- 2(CO)(4)(MeSCH2C(Me)(CH2S)(2))(CN)](-) (V), were investigated in the gas phase using photodetachment photoelectron spectroscopy. The adiabatic electron detachment energy (ADE) of each species and the intramolecular Coulomb repulsion for the doubly charged species were obtained. The ADEs correspond to the intrinsic redox potentials (in vacuo) of reactions involving the Fe(I)-Fe(I)/Fe(I)-Fe(II) couples in these compounds. The photoelectron spectra were understood and qualitatively assigned by comparing with that of Fe-2(CO)(6)S- 2, which has been well studied previously and exhibits similar valence spectral features as I-V. A''normal level scheme'' is suggested for the electronic structure of these low spin di- iron compounds, in which all occupied 3d levels lie above all occupied ligand levels. We also observed subtle differences in the electronic structures of the five di-iron complexes due to the slightly different ligand environments.

Yang, Xin; Razavet, Mathieu; Wang, Xue B.; Pickett, Chris J.; Wang, Lai S.

2003-06-12T23:59:59.000Z

432

LES Simulations of Roll Clouds Observed During Mixed- Phase Arctic Cloud Experiment  

SciTech Connect

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.

Greenberg, S.D.; Harrington, J.Y.; Prenni, A.; DeMott, P.

2005-03-18T23:59:59.000Z

433

Use of Synthetic Aperture Radar (SAR) for geologic reconnaissance in Arctic regions: An example from the Arctic National Wildlife Refuge, Alaska  

Science Conference Proceedings (OSTI)

Satellite-based synthetic aperture radar (SAR) can provide an additional remote-sensing tool for regional geologic studies in arctic regions. Although SAR data do not yield direct information on rock type and do not replace traditional optical data, SAR data can provide useful geologic information in arctic regions where the stratigraphic column includes a wide range of lithologies, and bedrock exposures have been reduced to rubble by frost action. For example, in ERS-1 SAR data from the Arctic National Wildlife Refuge (ANWR) of the northeastern Brooks Range, Alaska, carbonate and clastic rocks can give remarkably different radar responses on minimally reprocessed SAR data. The different radar response of different lithologies can specifically the size and angularity of scree in talus slopes. Additional postacquisition processing can both remove many of the negative terrain effects common in SAR data and enhance contrasts in bedrock lithology. Because of this ability to discriminate between gross lithologic packages, the ERS-1 SAR data can be used to provide a regional view of ANWR and a detailed look at specific areas. A mosaic of ERS-1 SAR data from all of ANWR provides a synoptic view of the regional structural framework, such as the anticlinoria of northern ANWR and the different allochthonous units of central and southern ANWR. Higher resolution ERS-1 SAR data of the Porcupine Lake area can be used to examine specific structural and stratigraphic problems associated with several major structural boundaries.

Hanks, C.L.; Guritz, R.M. [Univ. of Alaska, Fairbanks, AK (United States)

1997-01-01T23:59:59.000Z

434

2012 Changing Arctic Ocean 506E/497E -Lecture 1 -Woodgate What makes the  

E-Print Network (OSTI)

"? Decreasing Ice cover Local communities subsistence Arctic Shipping Routes? Oil/Gas Exploration Links INPUTS/OUTPUTS ­ E-P, rivers RIVERS (Russian and US) - order 3000 km3/yr freshwater Evaporation-Precipitation - order 2000 km3/yr freshwater Ice Export through the Fram Strait - equivalent to order 2000 km3/yr

Washington at Seattle, University of

435

A Variational Method for Computation of Sensible Heat Flux over the Arctic Sea Ice  

Science Conference Proceedings (OSTI)

In this study, a variational approach was employed to compute surface sensible heat flux over the Arctic sea ice. Because the variational approach is able to take into account information from the Monin–Obukhov similarity theory (MOST) as well as ...

Zuohao Cao; Jianmin Ma

2009-04-01T23:59:59.000Z

436

The Early Twentieth-Century Warming in the Arctic—A Possible Mechanism  

Science Conference Proceedings (OSTI)

The huge warming of the Arctic that started in the early 1920s and lasted for almost two decades is one of the most spectacular climate events of the twentieth century. During the peak period 1930–40, the annually averaged temperature anomaly for ...

Lennart Bengtsson; Vladimir A. Semenov; Ola M. Johannessen

2004-10-01T23:59:59.000Z

437

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

438

Impact of a Reduced Arctic Sea Ice Cover on Ocean and Atmospheric Properties  

Science Conference Proceedings (OSTI)

The Arctic sea ice cover declined over the last few decades and reached a record minimum in 2007, with a slight recovery thereafter. Inspired by this the authors investigate the response of atmospheric and oceanic properties to a 1-yr period of ...

Jan Sedlá?ek; Reto Knutti; Olivia Martius; Urs Beyerle

2012-01-01T23:59:59.000Z

439

Ice-Tethered Profiler Measurements of Dissolved Oxygen under Permanent Ice Cover in the Arctic Ocean  

Science Conference Proceedings (OSTI)

Four ice-tethered profilers (ITPs), deployed between 2006 and 2009, have provided year-round dissolved oxygen (DO) measurements from the surface mixed layer to 760-m depth under the permanent sea ice cover in the Arctic Ocean. These ITPs drifted ...

M.-L. Timmermans; R. Krishfield; S. Laney; J. Toole

2010-11-01T23:59:59.000Z

440

A Remotely Operated Lidar for Aerosol, Temperature, and Water Vapor Profiling in the High Arctic  

Science Conference Proceedings (OSTI)

A Rayleigh–Mie–Raman lidar has been installed and is operating in the Polar Environment Atmospheric Research Laboratory at Eureka in the High Arctic (79°59?N, 85°56?W) as part of the Canadian Network for the Detection of Atmospheric Change. The ...

G. J. Nott; T. J. Duck; J. G. Doyle; M. E. W. Coffin; C. Perro; C. P. Thackray; J. R. Drummond; P. F. Fogal; E. McCullough; R. J. Sica

2012-02-01T23:59:59.000Z

Note: This page contains sample records for the topic "modeling complex arctic" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


441

A Critical Examination of Satellite Cloud Retrieval from AVHRR in the Arctic Using SHEBA Data  

Science Conference Proceedings (OSTI)

This study examines the validity and limitations associated with retrieval of cloud optical depth ? and effective droplet size re in the Arctic from Advanced Very High Resolution Radiometer (AVHRR) channels 2 (0.725–1.10 ?m), 3 (3.55–3.93 ?m), ...

Xiaozhen Xiong; Dan Lubin; Wei Li; Knut Stamnes

2002-12-01T23:59:59.000Z

442

Arctic and boreal ecosystems of western North America as components of the climate system  

E-Print Network (OSTI)

*Institute of Arctic Biology, University of Alaska, Fairbanks, AK 99775, USA, ²US Geological Survey, Alaska, Colorado State University, Fort Collins, CO 80523, USA, ¶Atmospheric Turbulence and Diffusion Division, PO. Changes in thermokarst and the aerial extent of wetlands, lakes, and ponds would alter high

McGuire, A. David

443

Winter convection transports Atlantic Water heat to the surface layer in the eastern Arctic Ocean.  

Science Conference Proceedings (OSTI)

A one year (2009–2010) record of temperature and salinity profiles from Ice Tethered Profiler (ITP) buoys in the Eurasian Basin (EB) of the Arctic Ocean is used to quantify the flux of heat from the upper pycnocline to the surface mixed layer. The ...

Igor V. Polyakov; Andrey V. Pnyushkov; Robert Rember; Laurie Padman; Eddy C. Carmack; Jennifer M. Jackson

444

Ice properties of single-layer stratocumulus during the Mixed-Phase Arctic Cloud Experiment  

E-Print Network (OSTI)

Ice properties of single-layer stratocumulus during the Mixed-Phase Arctic Cloud Experiment: 2 opportunity to study poorly understood ice formation processes in mixed-phase stratocumulus. Using, were not significant sources of ice based on parameterizations from existing studies. After surveying

445

Influence of parameterized ice habit on simulated mixed phase Arctic clouds  

E-Print Network (OSTI)

Influence of parameterized ice habit on simulated mixed phase Arctic clouds Alexander Avramov1 12 February 2010. [1] The phase partitioning of cloud mass between liquid and ice in mixed phase clouds and its dependence on ambient ice nuclei (IN) concentrations and ice habit parameterizations

446

The distribution of neodymium isotopes in Arctic Ocean basins Don Porcelli a,*, Per S. Andersson b  

E-Print Network (OSTI)

, University of Oxford, Parks Road, Oxford OX1 3PR, UK b Laboratory for Isotope Geology, Swedish MuseumThe distribution of neodymium isotopes in Arctic Ocean basins Don Porcelli a,*, Per S. Andersson b of Natural History, Box 50007, SE-104 05 Stockholm, Sweden c Department of Geology, Wayne State University

Baskaran, Mark

447

Winter Convection Transports Atlantic Water Heat to the Surface Layer in the Eastern Arctic Ocean  

Science Conference Proceedings (OSTI)

A 1-yr (2009/10) record of temperature and salinity profiles from Ice-Tethered Profiler (ITP) buoys in the Eurasian Basin (EB) of the Arctic Ocean is used to quantify the flux of heat from the upper pycnocline to the surface mixed layer. The upper ...

Igor V. Polyakov; Andrey V. Pnyushkov; Robert Rember; Laurie Padman; Eddy C. Carmack; Jennifer M. Jackson

2013-10-01T23:59:59.000Z

448

Large-Scale Patterns and Variability of Snowmelt and Parameterized Surface Albedo in the Arctic Basin  

Science Conference Proceedings (OSTI)

Visible-band satellite imagery is used to manually map surface brightness changes over sea ice throughout the Arctic Basin from May to mid-August over a 10-yr period. These brightness changes are primarily due to snowmelt atop the ice cover. ...

David A. Robinson; Mark C. Serreze; Roger G. Barry; Greg Scharfen; George Kukla

1992-10-01T23:59:59.000Z

449

Soil Thermal and Ecological Impacts of Rain on Snow Events in the Circumpolar Arctic  

Science Conference Proceedings (OSTI)

Rain on snow (ROS) events are rare in most parts of the circumpolar Arctic, but have been shown to have great impact on soil surface temperatures and serve as triggers for avalanches in the midlatitudes, and they have been implicated in ...

Kevin J. Rennert; Gerard Roe; Jaakko Putkonen; Cecilia M. Bitz

2009-05-01T23:59:59.000Z

450

Potential Oil Production from the Coastal Plain of the Arctic National  

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

Potential Oil Production from the Coastal Plain of the Arctic National Wildlife Refuge: Updated Assessment 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 Coastal Plain of the Arctic National Wildlife Refuge: Updated Assessment, was prepared for the U.S. Senate Committee on Energy and Natural Resources at the request of Chairman Frank H. Murkowski in a letter dated March 10, 2000. The request asked the Energy Information Administration (EIA) to develop plausible scenarios for Arctic National Wildlife Refuge (ANWR) supply development consistent with the most recent U.S. Geological Survey (USGS) resource assessments. This report contains EIA projections of future daily production rates using recent USGS resource estimates. The Coastal Plain study area includes 1.5 million acres in the ANWR 1002 Area, 92,000 acres of Native Inupiat lands and State of Alaska offshore lands out to the 3-mile limit which are expected to be explored and developed if and when ANWR is developed. (Figure ES1) About 26 percent of the technically recoverable oil resources are in the Native and State lands.

451

Effects of Contemporary Winter Seismic Exploration on Low Arctic Plant Communities and Permafrost  

E-Print Network (OSTI)

: Todd.Kemper@gov.ab.ca Abstract We studied effects of oil and gas exploration, using the most recentEffects of Contemporary Winter Seismic Exploration on Low Arctic Plant Communities and Permafrost J seismic exploration technologies, on tundra plant communities and soils in four vegetation types

Macdonald, Ellen

452

Monitoring Precipitation over the Arctic Terrestrial Drainage System: Data Requirements, Shortcomings, and Applications of Atmospheric Reanalysis  

Science Conference Proceedings (OSTI)

An effort is under way aimed at historical analysis and monitoring of the pan-Arctic terrestrial drainage system. A key element is the provision of gridded precipitation time series that can be readily updated. This has proven to be a daunting ...

Mark C. Serreze; Martyn P. Clark; David H. Bromwich

2003-04-01T23:59:59.000Z

453

Eddies in the Canada Basin, Arctic Ocean, Observed from Ice-Tethered Profilers  

Science Conference Proceedings (OSTI)

Five ice-tethered profilers (ITPs), deployed between 2004 and 2006, have provided detailed potential temperature ? and salinity S profiles from 21 anticyclonic eddy encounters in the central Canada Basin of the Arctic Ocean. The 12–35-m-thick ...

M-L. Timmermans; J. Toole; A. Proshutinsky; R. Krishfield; A. Plueddemann

2008-01-01T23:59:59.000Z

454

Dynamics in the Deep Canada Basin, Arctic Ocean, Inferred by Thermistor Chain Time Series  

Science Conference Proceedings (OSTI)

A 50-day time series of high-resolution temperature in the deepest layers of the Canada Basin in the Arctic Ocean indicates that the deep Canada Basin is a dynamically active environment, not the quiet, stable basin often assumed. Vertical ...

M-L. Timmermans; H. Melling; L. Rainville

2007-04-01T23:59:59.000Z

455

Sea Ice Cover and Related Atmospheric Conditions in Arctic Canada During the Summer of 1978  

Science Conference Proceedings (OSTI)

Maps are presented of sea ice cover and open water in the Canadian Arctic for the final day of each month, June–September, 1978. The maps are derived from NOAA satellite imagery and show an extent of open water which is considerably smaller than ...

B. Dey

1980-12-01T23:59:59.000Z

456

Evolution of the Deep Water in the Canadian Basin in the Arctic Ocean  

Science Conference Proceedings (OSTI)

An overflow of magnitude 0.25 Sv (Sv ? 106 m?3 s?1) has been predicted to enter the Makarov Basin (part of the Canadian Basin in the Arctic Ocean) from the Eurasian Basin via a deep gap in the dividing Lomonosov ridge. The authors argue that this ...

M-L. Timmermans; Chris Garrett

2006-05-01T23:59:59.000Z

457

Posters A One-Dimensional Radiative Convective Model with Detailed Cloud Microphysics  

NLE Websites -- All DOE Office Websites (Extended Search)

5 5 Posters A One-Dimensional Radiative Convective Model with Detailed Cloud Microphysics J. Simmons, O. Lie-Svendsen, and K. Stamnes Geophysical Institute University of Alaska Fairbanks, Alaska The Arctic is a key element in determining the radiation budget of the earth. Within the polar regions, the net radiation (incoming solar radiation minus outgoing infrared radiation) is negative. To understand the role this energy deficit plays in the overall radiation budget, one must examine the prevalent atmospheric features of the Arctic. One such feature is a persistent layer of low-altitude, stratiform clouds found over the central Arctic predominantly from April to September (Tsay et al. 1984). These Arctic stratus clouds (ASC) modulate the earth's radiation budget

458

Probing 3'-ssDNA Loop Formation in E. coli RecBCD/RecBC-DNA Com-plexes using Non-natural DNA: A Model for "Chi" Recognition Complexes  

E-Print Network (OSTI)

in RecBCD-DNA Complexes Keywords: helicase; fluorescence; motor protein; recombination; thermodynamics with a Cy3-labeled reference DNA which undergoes a Cy3 fluorescence enhancement upon protein binding. We) and two series of non-fluorescent competitor DNA molecules (II and III in Figure 1a) for the reasons

Ju, Tao

459

Forecast Calls for Better Models: Examining the Core  

NLE Websites -- All DOE Office Websites (Extended Search)

Forecast Calls for Better Models: Examining the Core Forecast Calls for Better Models: Examining the Core Components of Arctic Clouds to Clear Their Influence on Climate For original submission and image(s), see ARM Research Highlights http://www.arm.gov/science/highlights/ Research Highlight Predicting how atmospheric aerosols influence cloud formation and the resulting feedback to climate is a challenge that limits the accuracy of atmospheric models. This is especially true in the Arctic, where mixed-phase (both ice- and liquid-based) clouds are frequently observed, but the processes that determine their composition are poorly understood. To obtain a closer look at what makes up Arctic clouds, scientists characterized cloud droplets and ice crystals collected at the North Slope of Alaska as part of the Indirect and Semi-Direct Aerosol Campaign (ISDAC) field study

460

Intercomparison of Bulk Cloud Microphysics Schemes in Mesoscale Simulations of Springtime Arctic Mixed-Phase Stratiform Clouds  

Science Conference Proceedings (OSTI)

A persistent, weakly forced, horizontally extensive mixed-phase boundary layer cloud observed on 4–5 May 1998 during the Surface Heat Budget of the Arctic Ocean (SHEBA)/First International Satellite Cloud Climatology Project (ISCCP) Regional ...

H. Morrison; J. O. Pinto

2006-07-01T23:59:59.000Z

Note: This page contains sample records for the topic "modeling complex arctic" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


461

On the control of the residual circulation and stratospheric temperatures in the Arctic by planetary wave coupling  

Science Conference Proceedings (OSTI)

It is well established that interannual variability of eddy (meridional) heat flux near the tropopause controls the variability of Arctic lower-stratospheric temperatures during spring via a modification of the strength of the residual ...

Tiffany A. Shaw; Judith Perlwitz

462

Arctic Ocean Radiative Fluxes and Cloud Forcing Estimated from the ISCCP C2 Cloud Dataset, 1983?1990  

Science Conference Proceedings (OSTI)

Radiative fluxes and cloud forcings for the ocean areas of the Arctic are computed from the monthly cloud product of the International Satellite Cloud Climatology Project (ISCCP) for 1983?90. Spatially averaged short-wave fluxes compare well with ...

Axel J. Schweiger; Jeffrey R. Key

1994-08-01T23:59:59.000Z

463

Arctic Surface, Cloud, and Radiation Properties Based on the AVHRR Polar Pathfinder Dataset. Part I: Spatial and Temporal Characteristics  

Science Conference Proceedings (OSTI)

With broad spectral coverage and high spatial and temporal resolutions, satellite sensors can provide the data needed for the analysis of spatial and temporal variations of climate parameters in data-sparse regions such as the Arctic and ...

Xuanji Wang; Jeffrey R. Key

2005-07-01T23:59:59.000Z

464

Atmospheric Radon Measurements in the Arctic; Fronts, Seasonal Observations, and Transport of Continental Air to Polar Regions  

Science Conference Proceedings (OSTI)

Radon was determined in the atmosphere over the Arctic Ocean in flights of a United States Naval Research Laboratory aircraft in April and May 1974. Simultaneously collected air samples were analyzed for carbon monoxide, methane, ...

P. E. Wilkniss; R. E. Larson

1984-08-01T23:59:59.000Z

465

Precipitation Features Observed by Doppler Radar at Tuktoyaktuk, Northwest Territories, Canada, during the Beaufort and Arctic Storms Experiment  

Science Conference Proceedings (OSTI)

In the fall of 1994, the Beaufort and Arctic Storms Experiment (BASE) was held to collect information on the structure and evolution of mesoscale weather systems over the southern Beaufort Sea and the Mackenzie River delta of the western Canadian ...

Yoshio Asuma; Soshi Iwata; Katsuhiro Kikuchi; G. W. Kent Moore; Ryuji Kimura; Kazuhisa Tsuboki

1998-09-01T23:59:59.000Z

466

Complex fission phenomena  

E-Print Network (OSTI)

Complex fission phenomena are studied in a unified way. Very general reflection asymmetrical equilibrium (saddle point) nuclear shapes are obtained by solving an integro-differential equation without being necessary to specify a certain parametrization. The mass asymmetry in binary cold fission of Th and U isotopes is explained as the result of adding a phenomenological shell correction to the liquid drop model deformation energy. Applications to binary, ternary, and quaternary fission are outlined.

D. N. Poenaru; R. A. Gherghescu; W. Greiner

2004-04-09T23:59:59.000Z

467

Simulations of Arctic mixed-phase clouds using a new aerosol-linked ice nuclei parameterization in a prognostic ice prediction scheme.  

E-Print Network (OSTI)

??Despite the nearly universally-accepted notion that the Arctic is one of the most important areas to fully understand in the face of a changing global… (more)

Carpenter, James Michael

2013-01-01T23:59:59.000Z

468

From Jimmy Carter to George W. Bush: Presidential Policies and Involvement in the Debate over the Arctic National Wildlife Refuge, 1977-2009.  

E-Print Network (OSTI)

??The Arctic National Wildlife Refuge (ANWR), located in the Northeastern corner of Alaska, has for the last three decades been the focus of one of… (more)

Eriksen, Gisle Holsbø

2009-01-01T23:59:59.000Z

469

Debatten om «The Arctic National Wildlife Refuge» (ANWR). : En diskursanalyse av ANWR-debatten i Representantenes hus i perioden 1995-2012.  

E-Print Network (OSTI)

??I over 50 år har debatten om området «The Arctic National Wildlife Refuge» (ANWR) pågått i amerikansk politikk. Debattens kjerne handler om man skal åpne… (more)

Kristiansen, Hanne Holm

2013-01-01T23:59:59.000Z

470

Potential Oil Production from the Coastal Plain of the Arctic National  

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 Arctic National Wildlife Refuge is the largest unexplored, potentially productive geologic onshore basin in the United States. The primary area of the coastal plain is the 1002 Area of ANWR established when ANWR was created. A decision on permitting the exploration and development of the 1002 Area is up to Congress and has not been approved to date. Also included in the Coastal Plain are State lands to the 3-mile offshore limit and Native Inupiat land near the village of Kaktovik. The USGS estimated: a 95 percent probability that at least 5.7 billion barrels of technically recoverable undiscovered oil are in the ANWR coastal plain,

471

Paleoreconstruction of Particulate Organic Carbon Inputs to the High-Arctic Colville River Delta, Beaufort Sea, Alaska  

E-Print Network (OSTI)

High Arctic permafrosted soils represent a massive sink in the global carbon cycle, 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 dissertation summarizes the results of the first study to look at long term, fine scale organic carbon delivery by the high-Arctic Colville River into Simpson’s Lagoon in the near-shore Beaufort Sea. Modern delivery of organic carbon to the Lagoon was determined to come from a variety of sources through the use of a three end-member mixing model and sediment biomarker concentrations. These sources include the Colville River in the western area of the Lagoon near the river mouth, marine sources in areas of the Lagoon without protective barrier islands, and coastal erosional sources and the Mackenzie River in the eastern area of the Lagoon. Downcore organic carbon delivery was measured on two cores in the Lagoon, one taken near the mouth of the Colville River (spans about 1800 years of history) and one taken on the eastern end of the Lagoon (spans about 600 years of history). Bulk organic parameters and biomarkers were measured in both cores and analyzed with Principle Component Analysis to determine long-term trends in organic carbon delivery. It was shown that at various times in the past, highly degraded organic carbon inputs of what is likely soil and peat carbon were delivered to the Lagoon. At other times, inputs of fresher, non-degraded, terrestrially-derived organic carbon inputs of what are likely higher amounts of plant and vegetative material was delivered to the Lagoon. Inputs of degraded soil carbon were also shown to correspond to higher temperatures on the North Slope of Alaska, likely indicating that warmer temperatures lead to a thawing of permafrost and in turn organic carbon mobilization to the coastal Beaufort Sea.

Schreiner, Kathryn 1983-

2013-05-01T23:59:59.000Z

472

Potential Oil Production from the Coastal Plain of the Arctic National  

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

Potential Oil Production from the Coastal Plain of the Arctic National Wildlife Refuge: Updated Assessment 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 National Wildlife Refuge: Updated Assessment is a product of the Energy Information Administration’s (EIA) Reserves and Production Division. EIA, under various programs, has assessed foreign and domestic oil and gas resources, reserves, and production potential. As a policy-neutral agency, EIA’s standard analysis of the potential of the Alaska North Slope (ANS) has focused on the areas without exploration and development restrictions. EIA received a letter (dated March 10, 2000) from Senator Frank H. Murkowski as Chairman of the Senate Committee on Energy and Natural Resources requesting an EIA Service Report "with plausible scenarios for ANWR supply development consistent with the most recent U.S. Geological Survey resource assessments." This service report is prepared in response to the request of Senator Murkowski. It focuses on the ANWR coastal plain, a region currently restricted from exploration and development, and updates EIA’s 1987 ANWR assessment.

473

A Nonlinear Steady-State Model of the North Water Polynya, Baffin Bay  

Science Conference Proceedings (OSTI)

A nonlinear, steady-state model of the North Water (NOW), the Arctic's largest polynya, is presented. The model follows in the spirit of the recently developed latent and sensible heat polynya model of Mysak and Huang, but extends it in several ...

M. S. Darby; A. J. Willmott; L. A. Mysak

1994-05-01T23:59:59.000Z

474

Simulating Arctic mixed-phase clouds: Sensitivity to environmental...  

NLE Websites -- All DOE Office Websites (Extended Search)

as well as aggregates to precipitation fluxes and radar reflectivity. Observations of icewater drop size distributions, cloud phase, etc., allow us to constrain model...

475

An evaluation of Bayesian techniques for controlling model complexity and selecting inputs in a neural network for short-term load forecasting  

Science Conference Proceedings (OSTI)

Artificial neural networks have frequently been proposed for electricity load forecasting because of their capabilities for the nonlinear modelling of large multivariate data sets. Modelling with neural networks is not an easy task though; two of the ... Keywords: Bayesian model selection, Bayesian neural networks, Input selection, Load forecasting

Henrique S. Hippert; James W. Taylor

2010-04-01T23:59:59.000Z

476

Radiative Energy Budget in the Cloudy and Hazy Arctic  

Science Conference Proceedings (OSTI)

A radiation model is constructed that includes radiative interactions with atmospheric gases as well as parameterized treatments of scattering and absorption/emission by cloud droplets and haze particles. A unified treatment of solar and ...

Si-Chee Tsay; Knut Stamnes; Kolf Jayaweera

1989-04-01T23:59:59.000Z

477

Attribution of Seasonal and Regional Changes in Arctic Moisture Convergence  

Science Conference Proceedings (OSTI)

Spatial and temporal changes in high-latitude moisture convergence simulated by the National Center for Atmospheric Research Community Climate System Model, version 3 (CCSM3) are investigated. Moisture convergence is calculated using the ...

Natasa Skific; Jennifer A. Francis; John J. Cassano

2009-10-01T23:59:59.000Z

478

Distribution and Validation of Cloud Cover Derived from AVHRR Data Over the Arctic Ocean During the SHEBA Year  

NLE Websites -- All DOE Office Websites (Extended Search)

and Validation of Cloud Cover and Validation of Cloud Cover Derived from AVHRR Data Over the Arctic Ocean During the SHEBA Year P. Minnis National Aeronautics and Space Administration Langley Research Center Hampton, Virginia D. A. Spangenberg and V. Chakrapani Analytical Services and Materials, Inc. Hampton, Virginia Introduction Determination of cloud radiation interactions over large areas of the Arctic is possible only with the use of data from polar orbiting satellites. Cloud detection using satellite data is difficult in the Arctic due to the minimal contrast between clouds and the underlying snow surface in visible and infrared wavelengths. Polar clouds are frequently warmer or at the same brightness temperature as the background surface, complicating cloud detection. The brightness temperature differences between the

479

Ranking management strategies with complex outcomes: An AHP-fuzzy evaluation of recreational fishing using an integrated agent-based model of a coral reef ecosystem  

Science Conference Proceedings (OSTI)

The management of recreational fishing requires resolving conflicting interests and is thus among the most controversial natural resource related issues. Decision making is difficult because of two main factors: first, there is lack of prediction tools ... Keywords: AHP, Agent-based model, Area closure, Decision support system, Fuzzy evaluation, Multiple criteria decision making, Non-market valuation, Random utility model, Recreational fishing

Lei Gao; Atakelty Hailu

2012-05-01T23:59:59.000Z

480

Microphysical Properties of Single and Mixed-Phase Arctic Clouds Derived from AERI Observations  

SciTech Connect

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.

Turner, David D.

2003-06-01T23:59:59.000Z

Note: This page contains sample records for the topic "modeling complex arctic" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


481

Predictions and Studies with a One-Dimensional Ice–Ocean Model  

Science Conference Proceedings (OSTI)

A coupled one-dimensional ice-ocean model is used for studies of Arctic phenomena. The ice-snow system is represented by the simplified thermodynamic ice model of Semtner and a dynamic approximation that neglects the internal stresses. The ocean ...

Shelley H. Riedlinger; Alex Warn-Varnas

1990-10-01T23:59:59.000Z

482

Dynamic–Thermodynamic Sea Ice Model: Ridging and Its Application to Climate Study and Navigation  

Science Conference Proceedings (OSTI)

A dynamic–thermodynamic sea ice model with the ocean mixed layer forced by atmospheric data is used to investigate spatial and long-term variability of the sea ice cover in the Arctic basin. The model satisfactorily reproduces the averaged main ...

Sergey V. Shoutilin; Alexander P. Makshtas; Motoyoshi Ikeda; Alexey V. Marchenko; Roman V. Bekryaev

2005-09-01T23:59:59.000Z