Powered by Deep Web Technologies
Note: This page contains sample records for the topic "improving atmospheric models" 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.


1

Evaluation of very long baseline interferometry atmospheric modeling improvements  

SciTech Connect

We determine the improvement in baseline length precision and accuracy using new atmospheric delay mapping functions and MTT by analyzing the NASA Crustal Dynamics Project research and development (R&D) experiments and the International Radio Interferometric Surveying (IRIS) A experiments. These mapping functions reduce baseline length scatter by about 20% below that using the CfA2.2 dry and Chao wet mapping functions. With the newer mapping functions, average station vertical scatter inferred from observed length precision (given by length repeatabilites) is 11.4 mm for the 1987-1990 monthly R&D series of experiments and 5.6 mm for the 3-week-long extended research and development experiment (ERDE) series. The inferred monthly R&D station vertical scatter is reduced by 2 mm or by 7 mm is a root-sum-square (rss) sense. Length repeatabilities are optimum when observations below a 7-8 deg elevation cutoff are removed from the geodetic solution. Analyses of IRIS-A data from 1984 through 1991 and the monthly R&D experiments both yielded a nonatmospheric unmodeled station vertical error or about 8 mm. In addition, analysis of the IRIS-A exeriments revealed systematic effects in the evolution of some baseline length measurements. The length rate of change has an apparent acceleration, and the length evolution has a quasi-annual signature. We show that the origin of these effects is unlikely to be related to atmospheric modeling errors. Rates of change of the transatlantic Westford-Wettzell and Richmond-Wettzell baseline lengths calculated from 1988 through 1991 agree with the NUVEL-1 plate motion model (Argus and Gordon, 1991) to within 1 mm/yr.

Macmillan, D.S.; Ma, C. [NASA, Goddard Space Flight Center, Greenbelt, MD (United States)] [NASA, Goddard Space Flight Center, Greenbelt, MD (United States)

1994-01-01T23:59:59.000Z

2

Atmospheric radiation measurement: A program for improving radiative forcing and feedback in general circulation models  

SciTech Connect

The Atmospheric Radiation Measurement (ARM) Program is a key element of the Department of Energy`s (DOE`s) global change research strategy. ARM represents a long-term commitment to conduct comprehensive studies of the spectral atmospheric radiative energy balance profile for a wide range of cloud conditions and surface types, and to develop the knowledge necessary to improve parameterizations of radiative processes under various cloud regimes for use in general circulation models (GCMs) and related models. The importance of the ARM program is a apparent from the results of model assessments of the impact on global climate change. Recent studies suggest that radiatively active trace gas emissions caused by human activity can lead to a global warming of 1.5 to 4.5 degrees Celsius and to important changes in water availability during the next century (Cess, et al. 1989). These broad-scale changes can be even more significant at regional levels, where large shifts in temperature and precipitation patterns are shown to occur. However, these analyses also indicate that considerable uncertainty exists in these estimates, with the manner in which cloud radiative processes are parameterized among the most significant uncertainty. Thus, although the findings have significant policy implications in assessment of global and regional climate change, their uncertainties greatly influence the policy debate. ARM`s highly focused observational and analytical research is intended to accelerate improvements and reduce key uncertainties associated with the way in which GCMs treat cloud cover and cloud characteristics and the resulting radiative forcing. This paper summarizes the scientific context for ARM, ARM`s experimental approach, and recent activities within the ARM program.

Patrinos, A.A. [USDOE, Washington, DC (United States); Renne, D.S.; Stokes, G.M. [Pacific Northwest Lab., Richland, WA (United States); Ellingson, R.G. [Maryland Univ., College Park, MD (United States)

1991-01-01T23:59:59.000Z

3

Atmospheric radiation measurement: A program for improving radiative forcing and feedback in general circulation models  

SciTech Connect

The Atmospheric Radiation Measurement (ARM) Program is a key element of the Department of Energy's (DOE's) global change research strategy. ARM represents a long-term commitment to conduct comprehensive studies of the spectral atmospheric radiative energy balance profile for a wide range of cloud conditions and surface types, and to develop the knowledge necessary to improve parameterizations of radiative processes under various cloud regimes for use in general circulation models (GCMs) and related models. The importance of the ARM program is a apparent from the results of model assessments of the impact on global climate change. Recent studies suggest that radiatively active trace gas emissions caused by human activity can lead to a global warming of 1.5 to 4.5 degrees Celsius and to important changes in water availability during the next century (Cess, et al. 1989). These broad-scale changes can be even more significant at regional levels, where large shifts in temperature and precipitation patterns are shown to occur. However, these analyses also indicate that considerable uncertainty exists in these estimates, with the manner in which cloud radiative processes are parameterized among the most significant uncertainty. Thus, although the findings have significant policy implications in assessment of global and regional climate change, their uncertainties greatly influence the policy debate. ARM's highly focused observational and analytical research is intended to accelerate improvements and reduce key uncertainties associated with the way in which GCMs treat cloud cover and cloud characteristics and the resulting radiative forcing. This paper summarizes the scientific context for ARM, ARM's experimental approach, and recent activities within the ARM program.

Patrinos, A.A. (USDOE, Washington, DC (United States)); Renne, D.S.; Stokes, G.M. (Pacific Northwest Lab., Richland, WA (United States)); Ellingson, R.G. (Maryland Univ., College Park, MD (United States))

1991-01-01T23:59:59.000Z

4

Improved HCN/HNC linelist, model atmospheres and synthetic spectra for WZ Cas  

E-Print Network (OSTI)

We build an accurate database of 5200 HCN and HNC rotation-vibration energy levels, determined from existing laboratory data. 20~000 energy levels in the Harris et al. (2002) linelist are assigned approximate quantum numbers. These assignments, lab determined energy levels and Harris et al (2002) energy levels are incorporated in to a new energy level list. A new linelist is presented, in which frequencies are computed using the lab determined energy levels where available, and the ab initio energy levels otherwise. The new linelist is then used to compute new model atmospheres and synthetic spectra for the carbon star WZ Cas. This results in better fit to the spectrum of WZ Cas in which the absorption feature at 3.56 micron is reproduced to a higher degree of accuracy than has previously been possible. We improve the reproduction of HCN absorption features by reducing the abundance of Si to [Si/H] = --0.5 dex, however, the strengths of the $\\Delta v=2$ CS band heads are over-predicted.

G. J. Harris; J. Tennyson; B. M. Kaminsky; Ya. V. Pavlenko; H. R. A. Jones

2005-12-14T23:59:59.000Z

5

Improvement of Moist and Radiative Processes in Highly Parallel Atmospheric General Circulation Models: Validation and Development  

SciTech Connect

Research on designing an integrated moist process parameterization package was carried. This work began with a study that coupled an ensemble of cloud models to a boundary layer model to examine the feasibility of such a methodology for linking boundary layer and cumulus parameterization schemes. The approach proved feasible, prompting research to design and evaluate a coupled parameterization package for GCMS. This research contributed to the development of an Integrated Cumulus Ensemble-Turbulence (ICET) parameterization package. This package incorporates a higher-order turbulence boundary layer that feeds information concerning updraft properties and the variances of temperature and water vapor to the cloud parameterizations. The cumulus ensemble model has been developed, and initial sensitivity tests have been performed in the single column model (SCM) version of CCM2. It is currently being coupled to a convective wake/gust front model. The major function of the convective wake/gust front model is to simulate the partitioning of the boundary layer into disturbed and undisturbed regions. A second function of this model is to predict the nonlinear enhancement of surface to air sensible heat and moisture fluxes that occur in convective regimes due to correlations between winds and anomalously cold, dry air from downdrafts in the gust front region. The third function of the convective wake/gust front model is to predict the amount of undisturbed boundary layer air lifted by the leading edge of the wake and the height to which this air is lifted. The development of the wake/gust front model has been completed, and it has done well in initial testing as a stand-alone component. The current task, to be completed by the end of the funding period, is to tie the wake model to a cumulus ensemble model and to install both components into the single column model version of CCM3 for evaluation. Another area of parametrization research has been focused on the representation of cloud radiative properties. An examination of the CCM2 simulation characteristics indicated that many surface temperature and warm land precipitation problems were linked to deficiencies in the specification of cloud optical properties, which allowed too much shortwave radiation to reach the surface. In-cloud liquid water path was statically specified in the CCM2 using a "prescribed, meridionally and height varying, but time independent, cloud liquid water density profile, which was analytically determined from a meridionally specified liquid water scale height. Single-column model integrations were conducted to explore alternative formulations for the cloud liquid water path diagnostic, converging on an approach that employs a similar, but state-dependent technique for determining in-cloud liquid water concentration. The new formulation, results in significant improvements to both the top-of- atmosphere and surface energy budgets. In particular, when this scheme is incorporated in the three-dimensional GCM, simulated July surface temperature biases are substantially reduced, where summer precipitation over the northern hemisphere continents, as well as precipitation rates over most all warm land areas, is more consistent with observations". This improved parameterization has been incorporated in the CCM3.

Frank, William M.; Hack, James J.; Kiehl, Jeffrey T.

1997-02-24T23:59:59.000Z

6

Improving Convection Parameterization Using ARM Observations and NCAR Community Atmosphere Model  

SciTech Connect

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

Zhang, Guang J [Scripps Institution of Oceanography

2013-07-29T23:59:59.000Z

7

Improving parameterization of scalar transport through vegetation in a coupled ecosystem-atmosphere model  

E-Print Network (OSTI)

Several regional-scale ecosystem models currently parameterize subcanopy scalar transport using a rough-wall boundary eddy diffusivity formulation. This formulation predicts unreasonably high soil evaporation beneath tall, ...

Link, Percy Anne

2008-01-01T23:59:59.000Z

8

Chemical modeling of exoplanet atmospheres  

E-Print Network (OSTI)

The past twenty years have revealed the diversity of planets that exist in the Universe. It turned out that most of exoplanets are different from the planets of our Solar System and thus, everything about them needs to be explored. Thanks to current observational technologies, we are able to determine some information about the atmospheric composition, the thermal structure and the dynamics of these exoplanets, but many questions remain still unanswered. To improve our knowledge about exoplanetary systems, more accurate observations are needed and that is why the Exoplanet Characterisation Observatory (EChO) is an essential space mission. Thanks to its large spectral coverage and high spectral resolution, EChO will provide exoplanetary spectra with an unprecedented accuracy, allowing to improve our understanding of exoplanets. In this work, we review what has been done to date concerning the chemical modeling of exoplanet atmospheres and what are the main characteristics of warm exoplanet atmospheres, which a...

Venot, Olivia

2014-01-01T23:59:59.000Z

9

Derivation of two models for noise due to atmospheric turbulence for improvement of resolution of beamforming algorithm  

E-Print Network (OSTI)

' the local wind conditions (speed and direction). The first model is idealized and a closed form solution is allowed. That is, the error induced by the wind can be eliminated within the beamforming algorithm. The second model is less idealized and a closed... in the direction of the acoustic waves propagating from the acoustic source is u. An array of AI acoustic sensors is assembled and a coordinate system is defined. Each sensor has position vector r, and a reference sensor is designated. See Figure 1. Note...

Hetmaniak, Joseph Christopher

2012-06-07T23:59:59.000Z

10

A Community Atmosphere Model with Superparameterized Clouds  

SciTech Connect

In 1999, National Center for Atmospheric Research (NCAR) scientists Wojciech Grabowski and Piotr Smolarkiewicz created a "multiscale" atmospheric model in which the physical processes associated with clouds were represented by running a simple high-resolution model within each grid column of a lowresolution global model. In idealized experiments, they found that the multiscale model produced promising simulations of organized tropical convection, which other models had struggled to produce. Inspired by their results, Colorado State University (CSU) scientists Marat Khairoutdinov and David Randall created a multiscale version of the Community Atmosphere Model (CAM). They removed the cloud parameterizations of the CAM, and replaced them with Khairoutdinov's high-resolution cloud model. They dubbed the embedded cloud model a "super-parameterization," and the modified CAM is now called the "SP-CAM." Over the next several years, many scientists, from many institutions, have explored the ability of the SP-CAM to simulate tropical weather systems, the day-night changes of precipitation, the Asian and African monsoons, and a number of other climate processes. Cristiana Stan of the Center for Ocean-Land-Atmosphere Interactions found that the SP-CAM gives improved results when coupled to an ocean model, and follow-on studies have explored the SP-CAM's utility when used as the atmospheric component of the Community Earth System Model. Much of this research has been performed under the auspices of the Center for Multiscale Modeling of Atmospheric Processes, a National Science Foundation (NSF) Science and Technology Center for which the lead institution is CSU.

Randall, David; Branson, Mark; Wang, Minghuai; Ghan, Steven J.; Craig, Cheryl; Gettelman, A.; Edwards, Jim

2013-06-18T23:59:59.000Z

11

Model Atmospheres for Low Field Neutron Stars  

E-Print Network (OSTI)

We compute model atmospheres and emergent spectra for low field (Bsolar abundance and iron atmospheres. We compare our results to high field magnetic atmospheres, available only for hydrogen. An application to apparently thermal flux from the low field millisecond pulsar PSR J0437--4715 shows that H atmospheres fit substantially better than Fe models. We comment on extension to high fields and the implication of these results for neutron star luminosities and radii.

Mohan Rajagopal; Roger Romani

1995-10-19T23:59:59.000Z

12

Performance Engineering in the Community Atmosphere Model  

SciTech Connect

The Community Atmosphere Model (CAM) is the atmospheric component of the Community Climate System Model (CCSM) and is the primary consumer of computer resources in typical CCSM simulations. Performance engineering has been an important aspect of CAM development throughout its existence. This paper briefly summarizes these efforts and their impacts over the past five years.

Worley, P; Mirin, A; Drake, J; Sawyer, W

2006-05-30T23:59:59.000Z

13

Soil moisture in complex terrain: quantifying effects on atmospheric boundary layer flow and providing improved surface boundary conditions for mesoscale models  

E-Print Network (OSTI)

compressible numerical weather prediction model incompressible numerical weather prediction model withcompressible numerical weather prediction model in

Daniels, Megan Hanako

2010-01-01T23:59:59.000Z

14

Visualizing Storms from NCAR's Atmosphere Model at NERSC  

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

Atmosphere Model Visualizing Storms from NCAR's Atmosphere Model CCSM-sprabhat.png Global warming will likely change the statistics of tropical cyclones and hurricanes. In this...

15

Surface Modification by Atmospheric Pressure Plasma for Improved Bonding  

E-Print Network (OSTI)

composites using atmospheric plasma treatment. J. Appl.of polymer surfaces: atmospheric plasma versus vacuum plasmaA. Morgan, The effect of atmospheric plasma treatment on the

Williams, Thomas Scott

2013-01-01T23:59:59.000Z

16

Stereographic displays of atmospheric model data  

Science Journals Connector (OSTI)

A system has been developed to display color stereographic time-lapsed sequences of outputs of three-dimensional atmospheric models. Contour lines and wind vectors derived from a model can be overlaid on a geostationary satellite image or displayed with ... Keywords: Computer graphics, Meteorology, Modeling display, Stereography

Mary desJardins; A. Frederick Hasler

1980-07-01T23:59:59.000Z

17

Adjoint modeling for atmospheric pollution process sensitivity at regional scale  

E-Print Network (OSTI)

Adjoint modeling for atmospheric pollution process sensitivity at regional scale Laurent Menut; 0345 Atmospheric Composition and Structure: Pollution--urban and regional (0305); 3210 Mathematical: atmospheric pollution, tropospheric ozone, urban pollution peaks, adjoint modeling, sensitivity Citation

Menut, Laurent

18

Improvement of Offshore Wind Resource Modeling in the Mid-  

E-Print Network (OSTI)

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

Firestone, Jeremy

19

Atmospheric Dispersion Modeling in Safety Analyses; GENII  

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

Workshop to Discuss Issues Regarding Deposition Workshop to Discuss Issues Regarding Deposition Velocity June 5-6, 2012 Jeremy Rishel Bruce Napier Atmospheric Dispersion Modeling in Safety Analyses: GENII Today's Presentation.... Will provide a high-level overview of the GENII codes. Will cover basic aspects of GENII's acute atmospheric transport model. Will review the GENII deposition model that is used to estimate the deposition velocity used in plume depletion. 2 GENII Development History 1988 - GENII V1 released ICRP-26/30/48 dosimetry 1990 - GENII V1.485 stabilized Current DOE Toolbox Version 1992 - GENII-S stochastic version 2004 - GENII V2 ICRP-72 age-dependent dosimetry Federal Guidance Report 13 risk factors

20

Improved steamflood analytical model  

E-Print Network (OSTI)

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

Chandra, Suandy

2006-10-30T23:59:59.000Z

Note: This page contains sample records for the topic "improving atmospheric models" 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

Parallel computing in atmospheric chemistry models  

SciTech Connect

Studies of atmospheric chemistry are of high scientific interest, involve computations that are complex and intense, and require enormous amounts of I/O. Current supercomputer computational capabilities are limiting the studies of stratospheric and tropospheric chemistry and will certainly not be able to handle the upcoming coupled chemistry/climate models. To enable such calculations, the authors have developed a computing framework that allows computations on a wide range of computational platforms, including massively parallel machines. Because of the fast paced changes in this field, the modeling framework and scientific modules have been developed to be highly portable and efficient. Here, the authors present the important features of the framework and focus on the atmospheric chemistry module, named IMPACT, and its capabilities. Applications of IMPACT to aircraft studies will be presented.

Rotman, D. [Lawrence Livermore National Lab., CA (United States). Atmospheric Sciences Div.

1996-02-01T23:59:59.000Z

22

Representing Grass and ShrubSnowAtmosphere Interactions in Climate System Models  

Science Journals Connector (OSTI)

A vegetation-protruding-above-snow parameterization for earth system models was developed to improve energy budget calculations of interactions among vegetation, snow, and the atmosphere in nonforested areas. These areas include shrublands, ...

Glen E. Liston; Christopher A. Hiemstra

2011-04-01T23:59:59.000Z

23

Atmospheric model intercomparison project: Monsoon simulations  

SciTech Connect

The simulation of monsoons, in particular the Indian summer monsoon, has proven to be a critical test of a general circulation model`s ability to simulate tropical climate and variability. The Monsoon Numerical Experimentation Group has begun to address questions regarding the predictability of monsoon extremes, in particular conditions associated with El Nino and La Nina conditions that tend to be associated with drought and flood conditions over the Indian subcontinent, through a series of seasonal integrations using analyzed initial conditions from successive days in 1987 and 1988. In this paper the authors present an analysis of simulations associated with the Atmospheric Model Intercomparison Project (AMIP), a coordinated effort to simulate the 1979--1988 decade using standardized boundary conditions with approximately 30 atmospheric general circulation models. The 13 models analyzed to date are listed. Using monthly mean data from these simulations they have calculated indices of precipitation and wind shear in an effort to access the performance of the models over the course of the AMIP decade.

Sperber, K.R. [Lawrence Livermore National Lab., CA (United States). Program for Climate Model Diagnosis and Intercomparison; Palmer, T.N. [European Centre for Medium-Range Weather Forecasts, Reading (United Kingdom)

1994-06-01T23:59:59.000Z

24

Singular Vector Analysis for Atmospheric Chemical Transport Models  

E-Print Network (OSTI)

are presented for a simulation of atmospheric pollution in East Asia in March 2001. The singular valuesSingular Vector Analysis for Atmospheric Chemical Transport Models Wenyuan Liao and Adrian Sandu for atmospheric chemical transport models. The distinguishing feature of these models is the presence of stiff

Sandu, Adrian

25

Discrete Packet Analysis for Improved Atmospheric Rejection on Modulated Laser Signals  

SciTech Connect

This slide-show discusses how the method of discrete packet analysis improves atmospheric compensation for quasi-CW fluorescence detection methods. This is key to improving remote sensing capabilities.

O'Neill, M., McKenna, I., DiBenedetto, J., Capelle, G., Trainham, R.

2012-07-19T23:59:59.000Z

26

Atmospheric transmittance model for photosynthetically active radiation  

SciTech Connect

A parametric model of the atmospheric transmittance in the PAR band is presented. The model can be straightforwardly applied for calculating the beam, diffuse and global components of the PAR solar irradiance. The required inputs are: air pressure, ozone, water vapor and nitrogen dioxide column content, ngstrm's turbidity coefficient and single scattering albedo. Comparison with other models and ground measured data shows a reasonable level of accuracy for this model, making it suitable for practical applications. From the computational point of view the calculus is condensed into simple algebra which is a noticeable advantage. For users interested in speed-intensive computation of the effective PAR solar irradiance, a PC program based on the parametric equations along with a user guide are available online at http://solar.physics.uvt.ro/srms.

Paulescu, Marius; Stefu, Nicoleta; Gravila, Paul; Paulescu, Eugenia; Boata, Remus; Pacurar, Angel; Mares, Oana [Physics Department, West University of Timisoara, V Parvan 4, 300223 Timisoara (Romania); Pop, Nicolina [Department of Physical Foundations of Engineering, Politehnica University of Timisoara, V Parvan 2, 300223 Timisoara (Romania); Calinoiu, Delia [Mechanical Engineering Faculty, Politehnica University of Timisoara, Mihai Viteazu 1, 300222 Timisoara (Romania)

2013-11-13T23:59:59.000Z

27

Subcycled dynamics in the Spectral Community Atmosphere Model, version 4  

SciTech Connect

To gain computational efficiency, a split explicit time integration scheme has been implemented in the CAM spectral Eulerian dynamical core. In this scheme, already present in other dynamical core options within the Community Atmosphere Model, version 4 (CAM), the fluid dynamics portion of the model is subcycled to allow a longer time step for the parameterization schemes. The physics parameterization of CAM is not subject to the stability restrictions of the fluid dynamics, and thus finer spatial resolutions of the model do not require the physics time step to be reduced. A brief outline of the subcycling algorithm implementation and resulting model efficiency improvement is presented. A discussion regarding the effect of the climate statistics derived from short model runs is provided.

Taylor, Mark [Sandia National Laboratories (SNL)] [Sandia National Laboratories (SNL); Evans, Katherine J [ORNL] [ORNL; Hack, James J [ORNL] [ORNL; Worley, Patrick H [ORNL] [ORNL

2010-01-01T23:59:59.000Z

28

Regional forecasting with global atmospheric models; Final report  

SciTech Connect

The purpose of the project was to conduct model simulations for past and future climate change with respect to the proposed Yucca Mtn. repository. The authors report on three main topics, one of which is boundary conditions for paleo-hindcast studies. These conditions are necessary for the conduction of three to four model simulations. The boundary conditions have been prepared for future runs. The second topic is (a) comparing the atmospheric general circulation model (GCM) with observations and other GCMs; and (b) development of a better precipitation data base for the Yucca Mtn. region for comparisons with models. These tasks have been completed. The third topic is preliminary assessments of future climate change. Energy balance model (EBM) simulations suggest that the greenhouse effect will likely dominate climate change at Yucca Mtn. for the next 10,000 years. The EBM study should improve rational choice of GCM CO{sub 2} scenarios for future climate change.

Crowley, T.J.; Smith, N.R. [Applied Research Corp., College Station, TX (United States)

1994-05-01T23:59:59.000Z

29

Atmospheric Chemistry, Modeling, and Biogeochemistry of Mercury  

E-Print Network (OSTI)

activities that release mercury to the atmosphere include coal burning, industrial processes, waste incine

30

Surface Modification by Atmospheric Pressure Plasma for Improved Bonding.  

E-Print Network (OSTI)

??An atmospheric pressure plasma source operating at temperatures below 150C and fed with 1.0-3.0 volume% oxygen in helium was used to activate the surfaces of (more)

Williams, Thomas Scott

2013-01-01T23:59:59.000Z

31

On Adaptive Mesh Refinement for Atmospheric Pollution Models  

E-Print Network (OSTI)

On Adaptive Mesh Refinement for Atmospheric Pollution Models Emil M. Constantinescu and Adrian Springer-Verlag Berlin Heidelberg 2005 #12;On Adaptive Mesh Refinement for Atmospheric Pollution Models 799 res- olution system for modeling regional air pollution based on the chemical transport model STEM

Sandu, Adrian

32

Targeted Observations for Atmospheric Chemistry and Transport Models  

E-Print Network (OSTI)

for a simulation of atmospheric pollution in East Asia in March 2001 show that the optimal location of observations, targeted observations. 1 Introduction Our ability to anticipate and manage changes in atmospheric pollutantTargeted Observations for Atmospheric Chemistry and Transport Models Adrian Sandu Department

Sandu, Adrian

33

Coupling Terrestrial and Atmospheric Water Dynamics to Improve Prediction in a Changing Environment  

E-Print Network (OSTI)

Fluxes across the land surface directly influence predictions of ecological processes, atmospheric dynamics, and terrestrial hydrology. However, many simplifications are made in numerical models when considering ...

Lyon, Steve W.; Dominguez, Francina; Gochis, David J.; Brunsell, Nathaniel A.; Castro, Christopher; Chow, Fotini K.; Fan, Ying; Fuka, Daniel; Hong, Yang; Kucera, Paul A.; Nesbitt, Stephen W.; Salzmann, Nadine; Schmidli, Juerg; Snyder, Peter K.; Teuling, Adriaam J.; Twine, Tracy E.; Levis, Samuel; Lundquist, Jessica D.; Salvucci, Guido D.; Sealy, Andrea M.; Walter, M. Todd

2008-09-01T23:59:59.000Z

34

IMPROVING AND EXPANDING PRECISION ORBIT DERIVED ATMOSPHERIC DENSITIES  

E-Print Network (OSTI)

, and the area facing the Earth, were determined so that these areas could be used to estimate the atmospheric drag, the force due to solar radiation pressure, and the force due to Earth radiation pressure (infrared and Earth albedo). This was done for both Terra...

Mysore Krishna, Dhaval

2012-05-31T23:59:59.000Z

35

Improved Adhesion of Dense Silica Coatings on Polymers by Atmospheric Plasma Pretreatment  

Science Journals Connector (OSTI)

Improved Adhesion of Dense Silica Coatings on Polymers by Atmospheric Plasma Pretreatment ... In another study,(7) which compared the treatments of low- and atmospheric-pressure plasmas, the authors reported that the low-pressure plasma treatment increased the adhesion with extended treatment time but prolonged atmospheric-pressure plasma treatment decreased the adhesion to epoxy. ... The authors begin with a brief overview of adhesion theory, and of the physics and chem. of cold plasmas. ...

Linying Cui; Alpana N. Ranade; Marvi A. Matos; Geraud Dubois; Reinhold H. Dauskardt

2013-08-13T23:59:59.000Z

36

Application of Improved Radiation Modeling to General Circulation Models  

SciTech Connect

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

Michael J Iacono

2011-04-07T23:59:59.000Z

37

Laboratory measurements and modeling of trace atmospheric species  

E-Print Network (OSTI)

Trace species play a major role in many physical and chemical processes in the atmosphere. Improving our understanding of the impact of each species requires a combination of laboratory exper- imentation, field measurements, ...

Sheehy, Philip M. (Philip Michael)

2005-01-01T23:59:59.000Z

38

Chapter 8: Modelling Sediment Records of Atmospherically Deposited Contaminants  

E-Print Network (OSTI)

73 Chapter 8: Modelling Sediment Records of Atmospherically Deposited Contaminants 8.1. Catchment the Water Column...............................................79 8.3 Water Column to Bottom Sediment Transfer......................................80 #12;Chapter 8: Modelling Sediment Records... 74 8

Short, Daniel

39

Modeling the effects of atmospheric emissions on groundwater composition  

SciTech Connect

A composite model of atmospheric, unsaturated and groundwater transport is developed to evaluate the processes determining the distribution of atmospherically derived contaminants in groundwater systems and to test the sensitivity of simulated contaminant concentrations to input parameters and model linkages. One application is to screen specific atmospheric emissions for their potential in determining groundwater age. Temporal changes in atmospheric emissions could provide a recognizable pattern in the groundwater system. The model also provides a way for quantifying the significance of uncertainties in the tracer source term and transport parameters on the contaminant distribution in the groundwater system, an essential step in using the distribution of contaminants from local, point source atmospheric emissions to examine conceptual models of groundwater flow and transport.

Brown, T.J.

1994-12-31T23:59:59.000Z

40

FOAM: Fast Ocean Atmosphere Model | Argonne National Laboratory  

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

FOAM: Fast Ocean Atmosphere Model FOAM: Fast Ocean Atmosphere Model FOAM: Fast Ocean Atmosphere Model FOAM is a fully coupled, mixed-resolution, general circulation model designed for high-throughput (simulated years per day) while still providing a good simulated mean climate and simulated variability. FOAM uses the combination of a low resolution (R15) atmosphere model, a highly efficient medium-resolution ocean model, and distributed memory parallel processing to achieve high throughput on relatively modest numbers of processors (16-64). The quality of the simulated climate compares well with higher resolution models. No flux corrections are used. FOAM's intended purpose is to study long-term natural variability in the climate system. FOAM is also well suited for paleoclimate applications. FOAM is highly

Note: This page contains sample records for the topic "improving atmospheric models" 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

Atmospheric Correction of Satellite Signal in Solar Domain: Impact of Improved Molecular Spectroscopy  

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

Atmospheric Correction of Satellite Signal in Solar Atmospheric Correction of Satellite Signal in Solar Domain: Impact of Improved Molecular Spectroscopy A. P. Trishchenko Canada Centre for Remote Sensing Ottawa, Ontario, Canada B. Hwang Intermap Technologies Corp. Calgary, Canada Z. Li University of Maryland and The Earth System Science Interdisciplinary Center College Park, Maryland Introduction Atmospheric correction of satellite measurements is a major step in the retrieval of surface reflective properties. It involves removing the effect of gaseous absorption as well as correcting for the effect of an atmospheric molecular and particulate scattering. In the past few years, there has been significant advancement in our knowledge of the absorbing properties of various atmospheric radiatively active

42

Extreme Precipitation in an Atmosphere General Circulation Model: Impact of Horizontal and Vertical Model Resolution  

Science Journals Connector (OSTI)

To investigate the influence of atmospheric model resolution on the representation of daily precipitation extremes, ensemble simulations with the atmospheric general circulation model ECHAM5 at different horizontal (T213 to T31) and vertical (L31 ...

Claudia Volosciuk; Douglas Maraun; Vladimir A. Semenov; Wonsun Park

43

Interactive Visualization of Modeled Atmospheric Trace Constituents Carmen M. Benkovitz  

E-Print Network (OSTI)

the effects of the emissions of Popocatepetl volcano, located near Mexico City. The effects of stronger of the Brookhaven National Laboratory Chemical Transport Model (CTM) of sulfate in the atmosphere. The visualization on climate. Anthropogenic activities affect the aerosol content of the atmosphere. Anthropogenic emissions

44

Predicting mesh density for adaptive modelling of the global atmosphere  

Science Journals Connector (OSTI)

...under investigation for atmospheric modelling for some time...atmosphere, using the shallow water equations-a necessary...to solve the shallow water equations on fixed meshes...discussed in 3. The mesh generator and the predictive adaptive...Solving the shallow water equations on polygons...

2009-01-01T23:59:59.000Z

45

Atmospheric models hybrid OpenMP/MPI implementation multicore cluster evaluation  

Science Journals Connector (OSTI)

Atmospheric models usually demand high processing power and generate large amounts of data. As the degree of parallelism grows, the I/O operations may become the major impacting factor of their performance. This work shows that a hybrid MPI/OpenMP implementation can improve the performance of the atmospheric model ocean-land-atmosphere model (OLAM) on a multicore cluster environment. We show that the hybrid MPI/OpenMP version of OLAM decreases the number of output files, resulting in better performance for I/O operations. We have evaluated OLAM on the parallel file system PVFS and shown that storing the files on PVFS results in lower performance than using the local disks of the cluster nodes due as a consequence of file creation and network concurrency. We have also shown that further parallel optimisations should be included in the hybrid version in order to improve the parallel execution time of OLAM.

Carla Osthoff; Francieli Zanon Boito; Rodrigo Virote Kassick; Laércio Lima Pilla; Philippe O.A. Navaux; Claudio Schepke; Jairo Panetta; Pablo Javier Grunmann; Nicolas Maillard; Pedro L. Silva Dias; Ro

2012-01-01T23:59:59.000Z

46

White Dwarf Spectra and Atmosphere Models  

E-Print Network (OSTI)

We describe the spectral classification of white dwarfs and some of the physical processes important for their understanding. In the major part of this paper we discuss the input physics and computational methods for one of the most widely used stellar atmosphere codes for white dwarfs.

Detlev Koester

2008-12-02T23:59:59.000Z

47

E-Print Network 3.0 - atmosphere model version Sample Search...  

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

coupling software Summary: linking the main model components of present-day Earth System models (ESMs), i.e. the atmosphere... be followed to couple ocean and atmosphere...

48

E-Print Network 3.0 - atmospheric models final Sample Search...  

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

coupling software Summary: linking the main model components of present-day Earth System models (ESMs), i.e. the atmosphere... be followed to couple ocean and atmosphere...

49

The Physical Properties of the Atmosphere in the New Hadley Centre Global Environmental Model (HadGEM1). Part I: Model Description and Global Climatology  

Science Journals Connector (OSTI)

The atmospheric component of the new Hadley Centre Global Environmental Model (HadGEM1) is described and an assessment of its mean climatology presented. HadGEM1 includes substantially improved representations of physical processes, increased ...

G. M. Martin; M. A. Ringer; V. D. Pope; A. Jones; C. Dearden; T. J. Hinton

2006-04-01T23:59:59.000Z

50

Coastal Atmospheric Circulation around an Idealized Cape during Wind-Driven Upwelling Studied from a Coupled OceanAtmosphere Model  

Science Journals Connector (OSTI)

The study analyzes atmospheric circulation around an idealized coastal cape during summertime upwelling-favorable wind conditions simulated by a mesoscale coupled oceanatmosphere model. The domain resembles an eastern ocean boundary with a ...

Natalie Perlin; Eric D. Skyllingstad; Roger M. Samelson

2011-03-01T23:59:59.000Z

51

Response of a Coupled OceanAtmosphere Model to Increasing Atmospheric Carbon Dioxide: Sensitivity to the Rate of Increase  

Science Journals Connector (OSTI)

The influence of differing rates of increase of the atmospheric CO2 concentration on the climatic response is investigated using a coupled oceanatmosphere model. Five transient integrations are performed each using a different constant ...

Ronald J. Stouffer; Syukuro Manabe

1999-08-01T23:59:59.000Z

52

Atmospheric Dispersion Model Validation in Low Wind Conditions  

SciTech Connect

Atmospheric plume dispersion models are used for a variety of purposes including emergency planning and response to hazardous material releases, determining force protection actions in the event of a Weapons of Mass Destruction (WMD) attack and for locating sources of pollution. This study provides a review of previous studies that examine the accuracy of atmospheric plume dispersion models for chemical releases. It considers the principles used to derive air dispersion plume models and looks at three specific models currently in use: Aerial Location of Hazardous Atmospheres (ALOHA), Emergency Prediction Information Code (EPIcode) and Second Order Closure Integrated Puff (SCIPUFF). Results from this study indicate over-prediction bias by the EPIcode and SCIPUFF models and under-prediction bias by the ALOHA model. The experiment parameters were for near field dispersion (less than 100 meters) in low wind speed conditions (less than 2 meters per second).

Sawyer, Patrick

2007-11-01T23:59:59.000Z

53

Ensemble operational air quality assessments in Europe Improving modeling platforms with statistical analysis  

E-Print Network (OSTI)

Ensemble operational air quality assessments in Europe ­ Improving modeling platforms. For regional air quality, seven regional modeling teams combine state-of-the-art atmospheric modeling the ensemble or a unique model. Keywords: Air quality, modeling system, ensemble approach, validation

Paris-Sud XI, Université de

54

Atmospheric Mercury Model Intercomparisons Presentation at  

E-Print Network (OSTI)

...NERI G. Petersen, R. Ebinghaus .................. Germany...GKSS J. Pacyna and Oxidants Model, GKSS Research Center, GermanyADOM MSC-E heavy metal regional model, EMEP MSC

55

Modeling Io's Sublimation-Driven Atmosphere: Gas Dynamics and Radiation Emission  

SciTech Connect

Io's sublimation-driven atmosphere is modeled using the direct simulation Monte Carlo method. These rarefied gas dynamics simulations improve upon earlier models by using a three-dimensional domain encompassing the entire planet computed in parallel. The effects of plasma impact heating, planetary rotation, and inhomogeneous surface frost are investigated. Circumplanetary flow is predicted to develop from the warm subsolar region toward the colder night-side. The non-equilibrium thermal structure of the atmosphere, including vibrational and rotational temperatures, is also presented. Io's rotation leads to an asymmetric surface temperature distribution which is found to strengthen circumplanetary flow near the dusk terminator. Plasma heating is found to significantly inflate the atmosphere on both day- and night-sides. The plasma energy flux also causes high temperatures at high altitudes but permits relatively cooler temperatures at low altitudes near the dense subsolar point due to plasma energy depletion. To validate the atmospheric model, a radiative transfer model was developed utilizing the backward Monte Carlo method. The model allows the calculation of the atmospheric radiation from emitting/absorbing and scattering gas using an arbitrary scattering law and an arbitrary surface reflectivity. The model calculates the spectra in the {nu}{sub 2} vibrational band of SO{sub 2} which are then compared to the observational data.

Walker, Andrew C.; Goldstein, David B.; Varghese, Philip L.; Trafton, Laurence M.; Moore, Chris H.; Stewart, Benedicte [University of Texas at Austin, Department of Aerospace Engineering, 210 East 24. Street W. R. Woolrich Laboratories 1 University Station, C0600 Austin, TX 78712 (United States); Gratiy, Sergey L.; Levin, Deborah A. [Pennsylvania State University, Department of Aerospace Engineering, 229 Hammond, University Park, PA 16802 (United States)

2008-12-31T23:59:59.000Z

56

A Model of the Cosmic Ray Induced Atmospheric Neutron Environment  

E-Print Network (OSTI)

In order to optimise the design of space instruments making use of detection materials with low atomic numbers, an understanding of the atmospheric neutron environment and its dependencies on time and position is needed. To produce a simple equation based model, Monte Carlo simulations were performed to obtain the atmospheric neutron fluxes produced by charged galactic cosmic ray interactions with the atmosphere. Based on the simulation results the omnidirectional neutron environment was parametrised including dependencies on altitude, magnetic latitude and solar activity. The upward- and downward-moving component of the atmospheric neutron flux are considered separately. The energy spectra calculated using these equations were found to be in good agreement with data from a purpose built balloon-borne neutron detector, high altitude aircraft data and previously published simulation based spectra.

Kole, Merlin; Salinas, Maria Muoz

2014-01-01T23:59:59.000Z

57

Modeling of Alpine Atmospheric Dynamics II  

E-Print Network (OSTI)

for large mesh sizes (x 20 km) to vertically redistribute heat and moisture in a grid column when model in a numerical model Convective cloud systems are not resolved if the mesh size of the grid is larger than small to treat convection as sub-grid scale process but too large to treat it explicitly For example

Gohm, Alexander

58

E-Print Network 3.0 - atmospheric models testing Sample Search...  

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

and Tectonics (COMET) Collection: Geosciences 7 BTRAM: An Interactive Atmospheric Radiative Transfer Model I.M. Chapman1 Summary: BTRAM: An Interactive Atmospheric Radiative...

59

E-Print Network 3.0 - atmospheric test models Sample Search Results  

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

and Tectonics (COMET) Collection: Geosciences 7 BTRAM: An Interactive Atmospheric Radiative Transfer Model I.M. Chapman1 Summary: BTRAM: An Interactive Atmospheric Radiative...

60

MULTISPECTRAL SYNTHETIC SCENE GENERATION USING ATMOSPHERIC PROPAGATION AND THERMODYNAMIC MODELS  

E-Print Network (OSTI)

of the Central Intelligence Agency, the US Department of Energy, NASA's Jet Propulsion Laboratory, ITEK a requirement. This document represents the current status of a first-principles physics-based synthetic image behavior in a natural environment, and the propagation of energy through the atmosphere. The model

Salvaggio, Carl

Note: This page contains sample records for the topic "improving atmospheric models" 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

Model projections of atmospheric steering of Sandy-like superstorms  

Science Journals Connector (OSTI)

...Polvani Adam H. Sobel aDepartment of Atmospheric Science, Colorado State University, Fort Collins, CO 80523;bDivision of Ocean...N Botzen WJW Emanuel K de Moel H ( 2013 ) Low-probability flood risk modeling for New York City . Risk Anal 33 ( 5 ): 772...

Elizabeth A. Barnes; Lorenzo M. Polvani; Adam H. Sobel

2013-01-01T23:59:59.000Z

62

White dwarf atmosphere models with Ly-$?$ opacity in the analysis of the white dwarf cooling sequence of NGC 6397  

E-Print Network (OSTI)

We discuss the importance of pure hydrogen white dwarf atmosphere models with Ly-$\\rm \\alpha$ far red wing opacity in the analysis of the white dwarf cooling sequence of the globular cluster NGC 6397. Our recently improved atmosphere models account for the previously missing opacity from the Ly-$\\rm \\alpha$ hydrogen line broadened by collisions of the absorbing hydrogen atoms with molecular and atomic hydrogen. These models are the first that well reproduce the UV colors and spectral energy distributions of cool white dwarfs with $T_{\\rm eff}white dwarf cooling sequence using atmosphere models that do not include the correct Ly-$\\alpha$ opacity is underestimated by $\\sim 0.5$ Gyr. Our analysis shows that it is essential to use white dwarf atmosphere models with Ly-$\\rm \\alpha$ opacity for precise dating of old stellar populations from white dwarf cooling sequences.

Piotr M. Kowalski

2007-08-28T23:59:59.000Z

63

A Hidden Markov Model Perspective on Regimes and Metastability in Atmospheric Flows  

Science Journals Connector (OSTI)

In this study, data from three atmospheric models are analyzed to investigate the existence of atmospheric flow regimes despite nearly Gaussian statistics of the planetary waves in these models. A hierarchy of models is used, which describes the ...

Christian Franzke; Daan Crommelin; Alexander Fischer; Andrew J. Majda

2008-04-01T23:59:59.000Z

64

Modeling of atmospheric corrosion behavior of weathering steel in sulfur dioxide-polluted atmospheres  

SciTech Connect

Atmospheric corrosion resistance of carbon steel (CS) and high-phosphorus weathering steel (WS, Acr-Ten A) was compared after exposure for up to 6 years in Taiwan. In an industrial atmosphere, corrosion kinetics of WS after 3 years of exposure deviated from behavior predicted by the well-known bilogarithmic law. This deviation was simulated using a laboratory accelerated test under cyclic wet/dry conditions with addition of 1 ppm sulfur dioxide (SO{sub 2}). In-situ electrochemical impedance measurements also were carried out in a modified three-electrode cell covered by a thin electrolyte layer to investigate corrosion behavior of WS in SO{sub 2}-polluted environments. Three impedance models were proposed to explain the characteristic corrosion behavior of WS in various stages of exposure.

Wang, J.H.; Shih, H.C. [National Tsing Hua Univ., Hsinchu (Taiwan, Province of China). Dept. of Materials Science and Engineering; Wei, F.I. [China Steel Corp., Kaoshiung (Taiwan, Province of China)

1996-12-01T23:59:59.000Z

65

Atmospheric plasma treatment to improve durability of a water and oil repellent finishing for acrylic fabrics  

Science Journals Connector (OSTI)

In this study, the influence of an atmospheric plasma treatment on the durability of a commercial water and oil repellent finish was tested. Acrylic fabrics were processed with a RF atmospheric pressure plasma generator and afterwards a fluorocarbon finish was applied through a traditional pad-dry-cure method. Two gas mixtures were tested (helium and helium/oxygen) with different plasma treatment times. The ageing of the finishing was simulated through repeated accelerated laundry cycles. The water and oil repellencies were measured through standard test methods. While the initial water and oil repellency did not change, the plasma treatment improved the durability of the finish after artificial ageing. Scanning electron microscopy analyses were carried out to highlight morphological changes.

Alberto Ceria; Peter J. Hauser

2010-01-01T23:59:59.000Z

66

The global change research center atmospheric chemistry model  

SciTech Connect

This work outlines the development of a new model of the chemistry of the natural atmosphere. The model is 2.5-dimensional, having spatial coordinates height, latitude, and, the half-dimension, land and ocean. The model spans both the troposphere and stratosphere, although the troposphere is emphasized and the stratosphere is simple and incomplete. The chemistry in the model includes the O{sub x}, HO{sub x}, NO{sub x}, and methane cycles in a highly modular fashion which allows model users great flexibility in selecting simulation parameters. A detailed modeled sensitivity analysis is also presented. A key aspect of the model is its inclusion of clouds. The model uses current understanding of the distribution and optical thickness of clouds to determine the true radiation distribution in the atmosphere. As a result, detailed studies of the radiative effects of clouds on the distribution of both oxidant concentrations and trace gas removal are possible. This work presents a beginning of this study with model results and discussion of cloud effects on the hydroxyl radical.

Moraes, F.P. Jr.

1995-01-01T23:59:59.000Z

67

Solar Radiation Estimated Through Mesoscale Atmospheric Modeling over Northeast Brazil  

Science Journals Connector (OSTI)

The use of renewable energy sources like solar wind and biomass is rapidly increasing in recent years with solar radiation as a particularly abundant energy source over Northeast Brazil. A proper quantitative knowledge of the incoming solar radiation is of great importance for energy planning in Brazil serving as basis for developing future projects of photovoltaic power plants and solar energy exploitation. This work presents a methodology for mapping the incoming solar radiation at ground level for Northeast Brazil using a mesoscale atmospheric model (Regional Atmospheric Modeling SystemRAMS) calibrated and validated using data from the network of automatic surface stations from the State Foundation for Meteorology and Water Resources from Cear (Fundao Cearense de Meteorologia e Recursos Hdricos? FUNCEME). The results showed that the model exhibits systematic errors overestimating surface radiation but that after the proper statistical corrections using a relationship between the model?predicted cloud fraction the ground?level observed solar radiation and the incoming solar radiation estimated at the top of the atmosphere a correlation of 0.92 with a confidence interval of 13.5? W / m 2 is found for monthly data. Using this methodology we found an estimate for annual average incoming solar radiation over Cear of 215? W / m 2 (maximum in October: 260? W / m 2 ).

Otacilio Leandro de Menezes Neto; Alexandre Arajo Costa; Fernando Pinto Ramalho; Paulo Henrique Santiago de Maria

2009-01-01T23:59:59.000Z

68

The Soil-Plant-Atmosphere model Manual, version 1.3, September 2005  

E-Print Network (OSTI)

handbook v 1.2 -2- Index The Soil-Plant-Atmosphere model................................................................................................................................. 3 Ecological and Physical Fundamentals................................................................................................................................. 29 #12;SPA handbook v 1.2 -3- Introduction The Soil-Plant-Atmosphere model (SPA, Williams et. al 1996

69

Model of Intraseasonal Oscillations in Earths Atmosphere  

Science Journals Connector (OSTI)

We suggest a way of rationalizing intraseasonal oscillations of Earths atmospheric flow as four meteorologically relevant triads of interacting planetary waves, isolated from the system of all of the rest of the planetary waves. Our model is independent of the topography (mountains, etc.) and gives a natural explanation of intraseasonal oscillations in both the Northern and the Southern Hemispheres. Spherical planetary waves are an example of a wave mesoscopic system obeying discrete resonances that also appears in other areas of physics.

Elena Kartashova and Victor S. Lvov

2007-05-10T23:59:59.000Z

70

Transient Responses of a Coupled OceanAtmosphere Model to Gradual Changes of Atmospheric CO2. Part I. Annual Mean Response  

Science Journals Connector (OSTI)

This study investigates the response of a climate model to a gradual increase or decrease of atmospheric carbon dioxide. The model is a general circulation model of the coupled atmosphere-ocean-land surface system with global geography and ...

S. Manabe; R. J. Stouffer; M. J. Spelman; K. Bryan

1991-08-01T23:59:59.000Z

71

Thermal shallow water models of geostrophic turbulence in Jovian atmospheres  

SciTech Connect

Conventional shallow water theory successfully reproduces many key features of the Jovian atmosphere: a mixture of coherent vortices and stable, large-scale, zonal jets whose amplitude decreases with distance from the equator. However, both freely decaying and forced-dissipative simulations of the shallow water equations in Jovian parameter regimes invariably yield retrograde equatorial jets, while Jupiter itself has a strong prograde equatorial jet. Simulations by Scott and Polvani [Equatorial superrotation in shallow atmospheres, Geophys. Res. Lett. 35, L24202 (2008)] have produced prograde equatorial jets through the addition of a model for radiative relaxation in the shallow water height equation. However, their model does not conserve mass or momentum in the active layer, and produces mid-latitude jets much weaker than the equatorial jet. We present the thermal shallow water equations as an alternative model for Jovian atmospheres. These equations permit horizontal variations in the thermodynamic properties of the fluid within the active layer. We incorporate a radiative relaxation term in the separate temperature equation, leaving the mass and momentum conservation equations untouched. Simulations of this model in the Jovian regime yield a strong prograde equatorial jet, and larger amplitude mid-latitude jets than the Scott and Polvani model. For both models, the slope of the non-zonal energy spectra is consistent with the classic Kolmogorov scaling, and the slope of the zonal energy spectra is consistent with the much steeper spectrum observed for Jupiter. We also perform simulations of the thermal shallow water equations for Neptunian parameter values, with a radiative relaxation time scale calculated for the same 25 mbar pressure level we used for Jupiter. These Neptunian simulations reproduce the broad, retrograde equatorial jet and prograde mid-latitude jets seen in observations. The much longer radiative time scale for the colder planet Neptune explains the transition from a prograde to a retrograde equatorial jet, while the broader jets are due to the deformation radius being a larger fraction of the planetary radius.

Warneford, Emma S., E-mail: emma.warneford@maths.ox.ac.uk; Dellar, Paul J., E-mail: dellar@maths.ox.ac.uk [OCIAM, Mathematical Institute, University of Oxford, Radcliffe Observatory Quarter, Oxford OX2 6GG (United Kingdom)

2014-01-15T23:59:59.000Z

72

Global Thermodynamic Atmospheric Modeling: Search for NewHeterogeneous Reactions  

SciTech Connect

This article demonstrates quantitatively how far reactions are from chemical equilibrium over the full space of a two-dimensional atmospheric model. This method could be used with data where an instrument-equipped aircraft measures numerous species simultaneously, An atmospheric reaction is displaced from equilibrium by solar radiation and relocation of species by atmospheric motions. One purpose of this study is to seek additional stratospheric or tropospheric gas-phase chemical reactions that might undergo heterogeneous catalysis. Hypothetical cases can be rapidly screened in terms of their thermodynamic potential to react under measured or modeled atmospheric conditions of temperature and local species concentrations. If a reaction is interesting, is slow in the gas phase, and has a high thermodynamic tendency to react, it is a good candidate for a laboratory study to seek a heterogeneous catalyst, if the reaction is thermodynamically unfavorable, there is no catalyst that can cause the reaction to occur. If a reaction is thermodynamically favored to occur but also endothermic, it will tend to be slow at stratospheric temperatures. We find, as expected, that four heterogeneous reactions important in causing the Antarctic ''ozone hole'' have high thermodynamic tendencies to occur under atmospheric conditions, but one of these is only weakly thermodynamically allowed in some regions of the atmosphere. The reaction of SO2 and HNO3 to form HONO has a high thermodynamic potential to occur, is a well-known laboratory reaction at ice temperature, and may occur in nitric acid-rich sulfate aerosols. Throughout the troposphere and stratosphere, we find that formaldehyde has an extremely high thermodynamic potential to reduce nitric acid. Formaldehyde is known to stick to and remain in sulfuric acid solution, where it adds water to form H2C(OH)(2). Near room-temperature H2C(OH)(2) reacts with nitric acid in a two-step mechanism to form two molecules of HONO, but the rate of this process under conditions of stratospheric sulfuric acid aerosols is unknown.

Fairbrother, D.H.; Sullivan, D.S.D.; Johnston, H.S.

1997-07-03T23:59:59.000Z

73

Improving Air Conditioner and Heat Pump Modeling  

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

Improving Air-Conditioner Improving Air-Conditioner and Heat Pump Modeling Building America Stakeholders Meeting Jon Winkler March 2, 2012 2 * How do you recommend the most cost-effective A/C? Simple Question 3 Solution Whole-House Simulation Tool A/C Information * SEER 13 * SEER 14 * SEER 15 * SEER 16 * SEER 17 * SEER 18 * SEER 21 Annualized Cooling Cost (Energy + Equipment) 4 Background * Power, capacity and SHR vary with: o Outdoor temperature o Entering wetbulb o Air mass flow rate o Part load ratio Power Sensible Capacity Latent Capacity * How to accurately and easily model A/C performance? 5 Background: Model Development * A/C modeling utilizes two types of input o Rated values (capacity, efficiency, etc.) o Performance curves Capacity 1 / Efficiency 6 Background: Manufacturer's Data

74

A Low Mach Number Model for Moist Atmospheric Flows  

E-Print Network (OSTI)

We introduce a low Mach number model for moist atmospheric flows that accurately incorporates reversible moist processes in flows whose features of interest occur on advective rather than acoustic time scales. Total water is used as a prognostic variable, so that water vapor and liquid water are diagnostically recovered as needed from an exact Clausius--Clapeyron formula for moist thermodynamics. Unlike the pseudo--incompressible formulation, this model allows a general equation of state. Low Mach number models can be computationally more efficient than a fully compressible model, but the low Mach number formulation introduces additional mathematical and computational complexity because of the divergence constraint imposed on the velocity field. Here, latent heat release is accounted for in the source term of the constraint by estimating the rate of phase change based on the time variation of saturated water vapor subject to the thermodynamic equilibrium constraint. We numerically assess the validity of the l...

Duarte, Max; Bell, John B

2014-01-01T23:59:59.000Z

75

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

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

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

76

E-Print Network 3.0 - atmospheric modeling based Sample Search...  

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

coefficient for moisture (4... linking the main model components of present-day Earth System models (ESMs), i.e. the atmosphere... that the exchanges between the ... Source:...

77

Evaluation of the Multi-scale Modeling Framework Using Data from the Atmospheric Radiation Measurement Program  

SciTech Connect

One of the goals of the Atmospheric Radiation Measurement (ARM) program is to provide long-term observations for evaluating and improving cloud and radiation treatment in global climate models. Unfortunately, the traditional parametric approach of diagnosing cloud and radiation properties for gridcells that are tens to hundreds kilometers across from large-scale model fields is not well suited for comparison with time series of ground based observations at selected locations. A recently emerging approach called a multi-scale modeling framework (MMF) has shown promise to bridge the scale gap. The MMF consists of a two-dimensional or small three-dimensional cloud resolving model (CRM) embedded into each grid column of the Community Atmospheric Model (CAM), thereby computing cloud properties at a scale that is more consistent with observations. We present a comparison of data from two ARM sites, one at the Southern Great Plains (SGP) in Oklahoma and one at Nauru Island in the Tropical Western Pacific (TWP) region, with output from both the CAM and MMF. Two sets of one year long simulations are considered: one using climatological sea surface temperatures (SST) and another using 1999 SST. Each set includes a run with the MMF as well as the CAM run with traditional or standard cloud and radiation treatment. Time series of cloud fraction, precipitation intensity, and downwelling solar radiation flux at the surface are statistically analyzed. For the TWP site, nearly all parameters of frequency distributions of these variables from the MMF run are shown to be more consistent with observation than those from the CAM run. This change is attributed to the improved representation of convective clouds in the MMF compared to the conventional climate model. For the SGP, the MMF shows little to no improvement in predicting the same quantities. Possible causes of this lack of improvement are discussed.

Ovtchinnikov, Mikhail; Ackerman, Thomas P.; Marchand, Roger T.; Khairoutdinov, Marat

2006-05-01T23:59:59.000Z

78

Modeling atmospheric deposition using a stochastic transport model  

SciTech Connect

An advanced stochastic transport model has been modified to include the removal mechanisms of dry and wet deposition. Time-dependent wind and turbulence fields are generated with a prognostic mesoscale numerical model and are used to advect and disperse individually released particles that are each assigned a mass. These particles are subjected to mass reduction in two ways depending on their physical location. Particles near the surface experience a decrease in mass using the concept of a dry deposition velocity, while the mass of particles located within areas of precipitation are depleted using a scavenging coefficient. Two levels of complexity are incorporated into the particle model. The simple case assumes constant values of dry deposition velocity and scavenging coefficient, while the more complex case varies the values according to meteorology, surface conditions, release material, and precipitation intensity. Instantaneous and cumulative dry and wet deposition are determined from the mass loss due to these physical mechanisms. A useful means of validating the model results is with data available from a recent accidental release of Cesium-137 from a steel-processing furnace in Algeciras, Spain in May, 1998. This paper describes the deposition modeling technique, as well as a comparison of simulated concentration and deposition with measurements taken for the Algeciras release.

Buckley, R.L.

1999-12-17T23:59:59.000Z

79

Detailed Atmosphere Modeling for the Neutron Star 1E1207.45209: Evidence of Oxygen/Neon Atmosphere  

Science Journals Connector (OSTI)

We present a comprehensive investigation of the two broad absorption features observed in the X-ray spectrum of the neutron star 1E1207.4-5209 based on a recent analysis of the 260 ks XMM-Newton data by Mori et al. Expanding on earlier work by Hailey & Mori, we have examined all previously proposed atmospheric models for 1E1207.4-5209. Using our atomic code, which rapidly solves Schrdinger's equation for arbitrary ions in strong magnetic field, we have systematically constructed atmospheric models by calculating polarization-dependent LTE opacities and addressed all the physics relevant to strongly magnetized plasmas. We have been able to rule out virtually all atmospheric models because they either do not sustain an ionization balance consistent with the claimed atmosphere composition or because they predict line strengths and line widths that are inconsistent with the data. Only oxygen or neon atmospheres at B ~ 1012 G provide self-consistent atmospheric solutions of the appropriate ionization balance that also have line widths, strengths, and energies consistent with the observations. The observed features are likely composed of several bound-bound transition lines from highly ionized oxygen/neon, and they are broadened primarily by motional Stark effects and magnetic field variation over the line-emitting region. Further considerations of plausible mechanisms for the formation of a mid-Z atmosphere likely rule out neon atmospheres and have important implications for the fallback mechanism in supernova ejecta. Future high-resolution spectroscopy missions such as Constellation-X will be able to resolve predicted substructure in the absorption features and will measure magnetic field strength and gravitational redshift independently to better than 10% accuracy.

Kaya Mori; Charles J. Hailey

2006-01-01T23:59:59.000Z

80

Improvements of surface functionality of cotton fibers by atmospheric plasma treatment  

Science Journals Connector (OSTI)

This study aims to investigate the viability of atmospheric plasma treatment over raw cotton fabric surfaces as ... , the fabric samples were treated with air plasma and argon atmospheric plasma. Thereafter, the ...

H. A. Karahan; E. zdo?an

2008-02-01T23:59:59.000Z

Note: This page contains sample records for the topic "improving atmospheric models" 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

Atmospheric component of the MPI-M Earth System Model: Bjorn Stevens,1  

E-Print Network (OSTI)

Atmospheric component of the MPI-M Earth System Model: ECHAM6 Bjorn Stevens,1 Marco Giorgetta,1: Stevens, B., et al. (2013), Atmospheric component of the MPI-M Earth System Model: ECHAM6, J. Adv. Model System Model (or MPI-ESM) is described in an accompanying paper (M. Giorgetta et al., Climate change from

Reichler, Thomas

82

Modeling the Exchanges of Energy, Water, and Carbon Between Continents and the Atmosphere  

E-Print Network (OSTI)

Modeling the Exchanges of Energy, Water, and Carbon Between Continents and the Atmosphere P. J, water vapor, and momentum across the land-atmosphere interface to be specified. These fluxes and the climate system to global change, for example, in- creasing atmospheric CO2 (1�3). Three generations

Collett Jr., Jeffrey L.

83

MANHAZ position paper on: Modelling of Pollutant Transport in the Atmosphere  

E-Print Network (OSTI)

MANHAZ position paper on: Modelling of Pollutant Transport in the Atmosphere Torben Mikkelsen July, Denmark I Atmospheric dispersion: Basic The dispersion of pollutants is intimately related to the state 2003 Atmospheric Physics Division Wind Energy Department Risø National Laboratory Dk-4000 Roskilde

84

NUMERICAL EXPERIMENTS USING MESONH/FOREFIRE COUPLED ATMOSPHERIC-FIRE MODEL  

E-Print Network (OSTI)

model inputting the wind fields and outputting heat and vapour fluxes to the atmospheric model. Fore mesh. Another originality of the approach is the fire rate of spread model that integrates wind effect of has been developed to add locale atmosphere interaction to the family of fire area simulators

Boyer, Edmond

85

High Resolution Atmospheric Modeling for Wind Energy Applications  

SciTech Connect

The ability of the WRF atmospheric model to forecast wind speed over the Nysted wind park was investigated as a function of time. It was found that in the time period we considered (August 1-19, 2008), the model is able to predict wind speeds reasonably accurately for 48 hours ahead, but that its forecast skill deteriorates rapidly after 48 hours. In addition, a preliminary analysis was carried out to investigate the impact of vertical grid resolution on the forecast skill. Our preliminary finding is that increasing vertical grid resolution does not have a significant impact on the forecast skill of the WRF model over Nysted wind park during the period we considered. Additional simulations during this period, as well as during other time periods, will be run in order to validate the results presented here. Wind speed is a difficult parameter to forecast due the interaction of large and small length scale forcing. To accurately forecast the wind speed at a given location, the model must correctly forecast the movement and strength of synoptic systems, as well as the local influence of topography / land use on the wind speed. For example, small deviations in the forecast track or strength of a large-scale low pressure system can result in significant forecast errors for local wind speeds. The purpose of this study is to provide a preliminary baseline of a high-resolution limited area model forecast performance against observations from the Nysted wind park. Validating the numerical weather prediction model performance for past forecasts will give a reasonable measure of expected forecast skill over the Nysted wind park. Also, since the Nysted Wind Park is over water and some distance from the influence of terrain, the impact of high vertical grid spacing for wind speed forecast skill will also be investigated.

Simpson, M; Bulaevskaya, V; Glascoe, L; Singer, M

2010-03-18T23:59:59.000Z

86

Formation of algae growth constitutive relations for improved algae modeling.  

SciTech Connect

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

Gharagozloo, Patricia E.; Drewry, Jessica L.

2013-01-01T23:59:59.000Z

87

COLLABORATIVE RESEARCH: CONTINUOUS DYNAMIC GRID ADAPTATION IN A GLOBAL ATMOSPHERIC MODEL: APPLICATION AND REFINEMENT  

SciTech Connect

This project had goals of advancing the performance capabilities of the numerical general circulation model EULAG and using it to produce a fully operational atmospheric global climate model (AGCM) that can employ either static or dynamic grid stretching for targeted phenomena. The resulting AGCM combined EULAGâ??s advanced dynamics core with the â??physicsâ? of the NCAR Community Atmospheric Model (CAM). Effort discussed below shows how we improved model performance and tested both EULAG and the coupled CAM-EULAG in several ways to demonstrate the grid stretching and ability to simulate very well a wide range of scales, that is, multi-scale capability. We leveraged our effort through interaction with an international EULAG community that has collectively developed new features and applications of EULAG, which we exploited for our own work summarized here. Overall, the work contributed to over 40 peer- reviewed publications and over 70 conference/workshop/seminar presentations, many of them invited.

Prusa, Joseph

2012-05-08T23:59:59.000Z

88

Plasma treatment of carbon fibres and glass-fibre-reinforced polyesters at atmospheric pressure for adhesion improvement  

Science Journals Connector (OSTI)

Atmospheric pressure plasma treatment is useful for adhesion improvement, because cleaning, roughening and addition of polar functional groups can be expected at the surfaces. Its possible applications in the wind energy industry include plasma treatment of fibres and fibre-reinforced polymer composites before assembling them to build wind turbine blades. In the present work, unsized carbon fibres are continuously treated using a dielectric barrier discharge plasma in helium at atmospheric pressure, and carbon fibre reinforced epoxy composite plates are manufactured for the mechanical test. The plasma treatment improved fracture toughness, indicating that adhesion between the fibres and the epoxy was enhanced by the treatment. In addition, glass-fibre-reinforced polyester plates are treated using a gliding arc and an ultrasound enhanced dielectric barrier discharge, improving the wettability and/or the adhesive strength with a vinylester resin.

Yukihiro Kusano; Tom L. Andersen; Helmuth L. Toftegaard; Frank Leipold; Alexander Bardenshtein; Niels Krebs

2014-01-01T23:59:59.000Z

89

Non-thermal atmospheric plasmas in dental restoration: Improved resin adhesive penetration  

Science Journals Connector (OSTI)

AbstractObjective To investigate the influence of non-thermal plasma treatment on the penetration of a model dental adhesive into the demineralized dentine. Methods Prepared dentine surfaces were conditioned with Scotchbond Universal etchant for 15s and sectioned equally perpendicular to the etched surfaces. The separated halves were randomly selected for treatment with an argon plasma brush (input current 6mA, treatment time 30s) or gentle argon air blowing (treatment time 30s, as control). The plasma-treated specimens and control specimens were applied with a model adhesive containing 2,2-bis[4-(2-hydroxy-3-methacryloxypropoxy) phenyl]-propane (BisGMA) and 2-hydroxyethyl methacrylate (HEMA) (mass ratio of 30/70), gently air-dried for 5s, and light-cured for 20s. Cross-sectional specimens were characterized using micro-Raman spectral mapping across the dentine, adhesive/dentine interface, and adhesive layer at 1-?m spatial resolution. SEM was also employed to examine the adhesive/dentine interfacial morphology. Results The micro-Raman result disclosed that plasma treatment significantly improved the penetration of the adhesive, evidenced by the apparently higher content of the adhesive at the adhesive/dentine interface as compared to the control. Specifically, the improvement of the adhesive penetration using plasma technique was achieved by dramatically enhancing the penetration of hydrophilic monomer (HEMA), while maintaining the penetration of hydrophobic monomer (BisGMA). Morphological observation at the adhesive/dentine interface using SEM also confirmed the improved adhesive penetration. The results further suggested that plasma treatment could benefit polymerization of the adhesive, especially in the interface region. Conclusion The significant role of the non-thermal plasma brush in improving the adhesive penetration into demineralized dentine has been demonstrated. The results obtained may offer a better prospect of using plasma in dental restoration to optimize adhesion between tooth substrate and restorative materials.

Ying Zhang; Qingsong Yu; Yong Wang

2014-01-01T23:59:59.000Z

90

Spatio-temporal statistical models with applications to atmospheric processes  

SciTech Connect

This doctoral dissertation is presented as three self-contained papers. An introductory chapter considers traditional spatio-temporal statistical methods used in the atmospheric sciences from a statistical perspective. Although this section is primarily a review, many of the statistical issues considered have not been considered in the context of these methods and several open questions are posed. The first paper attempts to determine a means of characterizing the semiannual oscillation (SAO) spatial variation in the northern hemisphere extratropical height field. It was discovered that the midlatitude SAO in 500hPa geopotential height could be explained almost entirely as a result of spatial and temporal asymmetries in the annual variation of stationary eddies. It was concluded that the mechanism for the SAO in the northern hemisphere is a result of land-sea contrasts. The second paper examines the seasonal variability of mixed Rossby-gravity waves (MRGW) in lower stratospheric over the equatorial Pacific. Advanced cyclostationary time series techniques were used for analysis. It was found that there are significant twice-yearly peaks in MRGW activity. Analyses also suggested a convergence of horizontal momentum flux associated with these waves. In the third paper, a new spatio-temporal statistical model is proposed that attempts to consider the influence of both temporal and spatial variability. This method is mainly concerned with prediction in space and time, and provides a spatially descriptive and temporally dynamic model.

Wikle, C.K.

1996-12-31T23:59:59.000Z

91

Scientific Final Report: COLLABORATIVE RESEARCH: CONTINUOUS DYNAMIC GRID ADAPTATION IN A GLOBAL ATMOSPHERIC MODEL: APPLICATION AND REFINEMENT  

SciTech Connect

This project had goals of advancing the performance capabilities of the numerical general circulation model EULAG and using it to produce a fully operational atmospheric global climate model (AGCM) that can employ either static or dynamic grid stretching for targeted phenomena. The resulting AGCM combined EULAG's advanced dynamics core with the 'physics' of the NCAR Community Atmospheric Model (CAM). Effort discussed below shows how we improved model performance and tested both EULAG and the coupled CAM-EULAG in several ways to demonstrate the grid stretching and ability to simulate very well a wide range of scales, that is, multi-scale capability. We leveraged our effort through interaction with an international EULAG community that has collectively developed new features and applications of EULAG, which we exploited for our own work summarized here. Overall, the work contributed to over 40 peer-reviewed publications and over 70 conference/workshop/seminar presentations, many of them invited.

William J. Gutowski; Joseph M. Prusa, Piotr K. Smolarkiewicz

2012-04-09T23:59:59.000Z

92

Extended Canadian middle atmosphere model: zonal-mean climatology and  

E-Print Network (OSTI)

and data assimilation; 3334 Meteorology and Atmospheric Dynamics: Middle atmosphere dynamics (0341, 0342 the Upper Atmos- phere Research Satellite (UARS), such as the Wind Imaging Interferometer (WINDII) [Shepherd and Dynamics (TIMED) satellite. These observations have provided (or will provide) a unique set of information

Wirosoetisno, Djoko

93

Climate Simulations for 19512050 with a Coupled AtmosphereOcean Model  

Science Journals Connector (OSTI)

The authors simulate climate change for 19512050 using the GISS SI2000 atmospheric model coupled to HYCOM, a quasi-isopycnal ocean model (ocean E), and contrast the results with those obtained using the same atmosphere coupled to a passive Q-...

Shan Sun; James E. Hansen

2003-09-01T23:59:59.000Z

94

Parameterization of urban sub-grid scale processes in global atmospheric chemistry models  

E-Print Network (OSTI)

-scale models. (submitted to Journal of Geophysical Research) #12;2 1. Introduction Atmospheric pollution has1 Parameterization of urban sub-grid scale processes in global atmospheric chemistry models Josep such as meteorology. Effective emissions may be ?aged? emissions of primary pollutants or actual production

95

Modeling the Atmospheric Boundary Layer Wind Response to Mesoscale Sea Surface Temperature  

E-Print Network (OSTI)

(WRF) and COAMPS atmospheric models. The SST-induced wind response is assessed from eight simulations of the surface wind relative to the SST gradient. #12;3 1. Introduction Positive correlations of local surfaceModeling the Atmospheric Boundary Layer Wind Response to Mesoscale Sea Surface Temperature Natalie

Kurapov, Alexander

96

Toward self-describing and workflow integrated Earth system models: A coupled atmosphere-ocean modeling system application  

Science Journals Connector (OSTI)

The complexity of Earth system models and their applications is increasing as a consequence of scientific advances, user demand, and the ongoing development of computing platforms, storage systems and distributed high-resolution observation networks. Multi-component Earth system models need to be redesigned to make interactions among model components and other applications external to the modeling system easier. To that end, the common component interfaces of Earth system models can be redesigned to increase interoperability between models and other applications such as various web services, data portals and science gateways. The models can be made self-describing so that the many configuration, build options and inputs of a simulation can be recorded. In this paper, we present a coupled modeling system that includes the proposed methodology to create self-describing models with common model component interfaces. The designed coupled atmosphere-ocean modeling system is also integrated into a scientific workflow system to simplify routine modeling tasks and relationships between these tasks and to demonstrate the enhanced interoperability between different technologies and components. Later on, the work environment is tested using a realistic Earth system modeling application. As can be seen through this example, a layered design for collecting provenance and metadata has the added benefit of documenting a run in far greater detail than before. In this way, it facilitates exploration and understanding of simulations and leads to possible reproducibility. In addition to designing self-describing Earth system models, the regular modeling tasks are also simplified and automated by using a scientific workflow which provides meaningful abstractions for the model, computing environment and provenance/metadata collection mechanisms. Our aim here is to solve a specific instance of a complex model integration problem by using a framework and scientific workflow approach together. The reader may also note that the methods presented in this paper might be also generalized to other types of Earth system models, leading to improved ease of use and flexibility. The initial results also show that the coupled atmosphere-ocean model, which is controlled by the designed workflow environment, is able to reproduce the Mediterranean Sea surface temperature when it is compared with the used CCSM3 initial and boundary conditions.

Ufuk Utku Turuncoglu; Nuzhet Dalfes; Sylvia Murphy; Cecelia DeLuca

2013-01-01T23:59:59.000Z

97

A MODEL ATMOSPHERE ANALYSIS OF ALPHA AURIGAE A  

SciTech Connect

This work presents the first quantitative composite model atmosphere analysis of Capella, the brightest near-equal-mass spectroscopic binary and principal star of the constellation Auriga. Its high-resolution spectrum leads to a slightly metal-rich object at [Fe/H] = +0.05 {+-} 0.08 dex. In line with its young age and its kinematics, this consistently associates Capella with the Hyades moving group. The measured projected rotational velocities, vsin i{sub Aa} = 3.5 {+-} 0.8 km s{sup -1} and vsin i{sub Ab} = 35.4 {+-} 3.2 km s{sup -1}, both agree with rotational and orbital coplanarity and synchronous orbital rotation for the Aa component. At an orbital period P = 104 d the primary's bound rotation together with the almost zero orbital eccentricity are both key characteristics of this binary and clearly imply that the Aa component must have passed the tip of the giant branch. Whether in that phase Capella also became a mass transfer system remains inconclusive at present, though the high rotational velocity of the less evolved Hertzsprung gap secondary and the very diverse lithium abundances of both its components render this a plausible case.

Fuhrmann, Klaus [Astronomisches Institut, Ruhr-Universitaet Bochum, Universitaetsstrasse 150, D-44780 Bochum (Germany)

2011-11-20T23:59:59.000Z

98

A Parameterization of Heterogeneous Land Surfaces for Atmospheric Numerical Models and Its Impact on Regional Meteorology  

Science Journals Connector (OSTI)

Natural land surfaces are usually heterogeneous over the resolvable scales considered in atmospheric numerical models. Therefore, model surface parameterizations that assume surface homogeneity may fail to represent the surface forcing ...

R. Avissar; R. A. Pielke

1989-10-01T23:59:59.000Z

99

A Blended Soundproof-to-Compressible Numerical Model for Small- to Mesoscale Atmospheric Dynamics  

Science Journals Connector (OSTI)

A blended model for atmospheric flow simulations is introduced that enables seamless transition from fully compressible to pseudo-incompressible dynamics. The model equations are written in nonperturbation form and integrated using a well-balanced ...

Tommaso Benacchio; Warren P. ONeill; Rupert Klein

2014-12-01T23:59:59.000Z

100

The second Hadley Centre coupled ocean-atmosphere GCM: model description, spinup and validation  

Science Journals Connector (OSTI)

...?This study describes a new coupled ocean-atmosphere general circulation model (OAGCM) developed for studies of climate change and results from a hindcast experiment. The model includes various physical and te...

T. C. Johns; R. E. Carnell; J. F. Crossley; J. M. Gregory

1997-02-01T23:59:59.000Z

Note: This page contains sample records for the topic "improving atmospheric models" 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

Evaluation of the Multi-Scale Modeling Framework using Data from the Atmospheric Radiation Measurement Program  

SciTech Connect

One of the goals of the Atmospheric Radiation Measurement (ARM) program was to provide long-term observations for evaluation of cloud and radiation treatment in global climate models. Unfortunately, traditional parametric approach of diagnosing cloud and radiation properties from large-scale model fields is not well suited for comparison with observed time series at selected locations. A recently emerging approach called the multi-scale modeling framework (MMF) has shown promise to bridge the gap. MMF consists of a two-dimensional cloud system resolving model (CSRM) embedded into each CAM grid column of the Community Atmospheric Model (CAM), thereby computing cloud properties at a scale that is more consistent with observations. Because the approach is computationally expensive only limited simulations have been carried out. In this presentation, we will present a comparison of data from two ARM sites, one at the Southern Great Plains (SGP) in Oklahoma and one at Nauru island in the Tropical Western Pacific (TWP) region, with output from both CAM and MMF. Two sets of one year long simulations are considered: one using climatological sea surface temperatures (SST) and another using 1999 SST. Each set includes a run with MMF as well as CAM run with traditional or standard cloud and radiation treatment. Time series of cloud fraction, precipitation intensity, and downwelling solar radiation flux at the surface are statistically analyzed. For the TWP site, nearly all parameters of frequency distributions of these variables from MMF run are shown to be more consistent with observation than those from CAM run. For the SGP, the improvements are marginal.

Ovchinnikov, Mikhail; Ackerman, Thomas P.; Marchand, Roger T.; Khairoutdinov, Marat

2004-07-01T23:59:59.000Z

102

The Carbon-Land Model Intercomparison Project (C-LAMP): A Model-Data Comparison System for Evaluation of Coupled Biosphere-Atmosphere Models  

SciTech Connect

The need to capture important climate feebacks in general circulation models (GCMs) has resulted in new efforts to include atmospheric chemistry and land and ocean biogeochemistry into the next generation of production climate models, now often referred to as Earth System Models (ESMs). While many terrestrial and ocean carbon models have been coupled to GCMs, recent work has shown that such models can yield a wide range of results, suggesting that a more rigorous set of offline and partially coupled experiments, along with detailed analyses of processes and comparisons with measurements, are warranted. The Carbon-Land Model Intercomparison Project (C-LAMP) provides a simulation protocol and model performance metrics based upon comparisons against best-available satellite- and ground-based measurements (Hoffman et al., 2007). C-LAMP provides feedback to the modeling community regarding model improvements and to the measurement community by suggesting new observational campaigns. C-LAMP Experiment 1 consists of a set of uncoupled simulations of terrestrial carbon models specifically designed to examine the ability of the models to reproduce surface carbon and energy fluxes at multiple sites and to exhibit the influence of climate variability, prescribed atmospheric carbon dioxide (CO{sub 2}), nitrogen (N) deposition, and land cover change on projections of terrestrial carbon fluxes during the 20th century. Experiment 2 consists of partially coupled simulations of the terrestrial carbon model with an active atmosphere model exchanging energy and moisture fluxes. In all experiments, atmospheric CO{sub 2} follows the prescribed historical trajectory from C{sup 4}MIP. In Experiment 2, the atmosphere model is forced with prescribed sea surface temperatures (SSTs) and corresponding sea ice concentrations from the Hadley Centre; prescribed CO{sub 2} is radiatively active; and land, fossil fuel, and ocean CO{sub 2} fluxes are advected by the model. Both sets of experiments have been performed using two different terrestrial biogeochemistry modules coupled to the Community Land Model version 3 (CLM3) in the Community Climate System Model version 3 (CCSM3): The CASA model of Fung, et al., and the carbon-nitrogen (CN) model of Thornton. Comparisons against Ameriflus site measurements, MODIS satellite observations, NOAA flask records, TRANSCOM inversions, and Free Air CO{sub 2} Enrichment (FACE) site measurements, and other datasets have been performed and are described in Randerson et al. (2009). The C-LAMP diagnostics package was used to validate improvements to CASA and CN for use in the next generation model, CLM4. It is hoped that this effort will serve as a prototype for an international carbon-cycle model benchmarking activity for models being used for the Inter-governmental Panel on Climate Change (IPCC) Fifth Assessment Report. More information about C-LAMP, the experimental protocol, performance metrics, output standards, and model-data comparisons from the CLM3-CASA and CLM3-CN models are available at http://www.climatemodeling.org/c-lamp.

Hoffman, Forrest M [ORNL; Randerson, Jim [University of California, Irvine; Thornton, Peter E [ORNL; Mahowald, Natalie [Cornell University; Bonan, Gordon [National Center for Atmospheric Research (NCAR); Running, Steven [University of Montana, Missoula; Fung, Inez [University of California, Berkeley

2009-01-01T23:59:59.000Z

103

Evaluation of Hydrometeor Occurrence Profiles in the Multiscale Modeling Framework Climate Model using Atmospheric Classification  

SciTech Connect

Vertical profiles of hydrometeor occurrence from the Multiscale Modeling Framework (MMF) climate model are compared with profiles observed by a vertically pointing millimeter wavelength cloud-radar (located in the U.S. Southern Great Plains) as a function of the largescale atmospheric state. The atmospheric state is determined by classifying (or clustering) the large-scale (synoptic) fields produced by the MMF and a numerical weather prediction model using a neural network approach. The comparison shows that for cold frontal and post-cold frontal conditions the MMF produces profiles of hydrometeor occurrence that compare favorably with radar observations, while for warm frontal conditions the model tends to produce hydrometeor fractions that are too large with too much cloud (non-precipitating hydrometeors) above 7 km and too much precipitating hydrometeor coverage below 7 km. We also find that the MMF has difficulty capturing the formation of low clouds and that for all atmospheric states that occur during June, July, and August, the MMF produces too much high and thin cloud, especially above 10 km.

Marchand, Roger T.; Beagley, Nathaniel; Ackerman, Thomas P.

2009-09-01T23:59:59.000Z

104

Satellite Data Assimilation in Numerical Weather Prediction Models. Part I: Forward Radiative Transfer and Jacobian Modeling in Cloudy Atmospheres  

Science Journals Connector (OSTI)

Satellite data assimilation requires rapid and accurate radiative transfer and radiance gradient models. For a vertically stratified scattering and emitting atmosphere, the vector discrete-ordinate radiative transfer model (VDISORT) was developed ...

Fuzhong Weng; Quanhua Liu

2003-11-01T23:59:59.000Z

105

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

E-Print Network (OSTI)

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

Wang, Chien.; Prinn, Ronald G.

106

HIGH-RESOLUTION ATMOSPHERIC ENSEMBLE MODELING AT SRNL  

SciTech Connect

The High-Resolution Mid-Atlantic Forecasting Ensemble (HME) is a federated effort to improve operational forecasts related to precipitation, convection and boundary layer evolution, and fire weather utilizing data and computing resources from a diverse group of cooperating institutions in order to create a mesoscale ensemble from independent members. Collaborating organizations involved in the project include universities, National Weather Service offices, and national laboratories, including the Savannah River National Laboratory (SRNL). The ensemble system is produced from an overlapping numerical weather prediction model domain and parameter subsets provided by each contributing member. The coordination, synthesis, and dissemination of the ensemble information are performed by the Renaissance Computing Institute (RENCI) at the University of North Carolina-Chapel Hill. This paper discusses background related to the HME effort, SRNL participation, and example results available from the RENCI website.

Buckley, R.; Werth, D.; Chiswell, S.; Etherton, B.

2011-05-10T23:59:59.000Z

107

COLLABORATIVE RESEARCH: CONTINUOUS DYNAMIC GRID ADAPTATION IN A GLOBAL ATMOSPHERIC MODEL: APPLICATION AND REFINEMENT  

SciTech Connect

This project had goals of advancing the performance capabilities of the numerical general circulation model EULAG and using it to produce a fully operational atmospheric global climate model (AGCM) that can employ either static or dynamic grid stretching for targeted phenomena. The resulting AGCM combined EULAG's advanced dynamics core with the "physics" of the NCAR Community Atmospheric Model (CAM). Effort discussed below shows how we improved model performance and tested both EULAG and the coupled CAM-EULAG in several ways to demonstrate the grid stretching and ability to simulate very well a wide range of scales, that is, multi-scale capability. We leveraged our effort through interaction with an international EULAG community that has collectively developed new features and applications of EULAG, which we exploited for our own work summarized here. Overall, the work contributed to over 40 peer-reviewed publications and over 70 conference/workshop/seminar presentations, many of them invited. 3a. EULAG Advances EULAG is a non-hydrostatic, parallel computational model for all-scale geophysical flows. EULAG's name derives from its two computational options: EULerian (flux form) or semi-LAGrangian (advective form). The model combines nonoscillatory forward-in-time (NFT) numerical algorithms with a robust elliptic Krylov solver. A signature feature of EULAG is that it is formulated in generalized time-dependent curvilinear coordinates. In particular, this enables grid adaptivity. In total, these features give EULAG novel advantages over many existing dynamical cores. For EULAG itself, numerical advances included refining boundary conditions and filters for optimizing model performance in polar regions. We also added flexibility to the model's underlying formulation, allowing it to work with the pseudo-compressible equation set of Durran in addition to EULAG's standard anelastic formulation. Work in collaboration with others also extended the demonstrated range of validity of soundproof models, showing that they are more broadly applicable than some had previously thought. Substantial testing of EULAG included application and extension of the Jablonowski-Williamson baroclinic wave test - an archetype of planetary weather - and further analysis of multi-scale interactions arising from collapse of temperature fronts in both the baroclinic wave test and simulations of the Held-Suarez idealized climate. These analyses revealed properties of atmospheric gravity waves not seen in previous work and further demonstrated the ability of EULAG to simulate realistic behavior over several orders of magnitude of length scales. Additional collaborative work enhanced capability for modeling atmospheric flows with adaptive moving meshes and demonstrated the ability of EULAG to move into petascale computing. 3b. CAM-EULAG Advances We have developed CAM-EULAG in collaboration with former project postdoc, now University of Cape Town Assistant Professor, Babatunde Abiodun. Initial study documented good model performance in aqua-planet simulations. In particular, we showed that the grid adaptivity (stretching) implemented in CAM-EULAG allows higher resolution in selected regions without causing anomalous behavior such as spurious wave reflection. We then used the stretched-grid version to analyze simulated extreme precipitation events in West Africa, comparing the precipitation and event environment with observed behavior. The model simulates fairly well the spatial scale and the interannual and intraseasonal variability of the extreme events, although its extreme precipitation intensity is weaker than observed. In addition, both observations and the simulations show possible forcing of extreme events by African easterly waves. 3c. Other Contributions Through our collaborations, we have made contributions to a wide range of outcomes. For research focused on terrestrial behavior, these have included (1) upwind schemes for gas dynamics, (2) a nonlinear perspective on the dynamics of the Madden-Julian Oscillation, (3) numerical realism of thermal co

Gutowski, William J.; Prusa, Joseph M.; Smolarkiewicz, Piotr K.

2012-05-08T23:59:59.000Z

108

Improvement of snowpack simulations in a regional climate model  

SciTech Connect

To improve simulations of regional-scale snow processes and related cold-season hydroclimate, the Community Land Model version 3 (CLM3), developed by the National Center for Atmospheric Research (NCAR), was coupled with the Pennsylvania State University/NCAR fifth-generation Mesoscale Model (MM5). CLM3 physically describes the mass and heat transfer within the snowpack using five snow layers that include liquid water and solid ice. The coupled MM5CLM3 model performance was evaluated for the snowmelt season in the Columbia River Basin in the Pacific Northwestern United States using gridded temperature and precipitation observations, along with station observations. The results from MM5CLM3 show a significant improvement in the SWE simulation, which has been underestimated in the original version of MM5 coupled with the Noah land-surface model. One important cause for the underestimated SWE in Noah is its unrealistic land-surface structure configuration where vegetation, snow and the topsoil layer are blended when snow is present. This study demonstrates the importance of the sheltering effects of the forest canopy on snow surface energy budgets, which is included in CLM3. Such effects are further seen in the simulations of surface air temperature and precipitation in regional weather and climate models such as MM5. In addition, the snow-season surface albedo overestimated by MM5Noah is now more accurately predicted by MM5CLM3 using a more realistic albedo algorithm that intensifies the solar radiation absorption on the land surface, reducing the strong near-surface cold bias in MM5Noah. The cold bias is further alleviated due to a slower snowmelt rate in MM5CLM3 during the early snowmelt stage, which is closer to observations than the comparable components of MM5Noah. In addition, the over-predicted precipitation in the Pacific Northwest as shown in MM5Noah is significantly decreased in MM5 CLM3 due to the lower evaporation resulting from the longer snow duration.

Jin, J.; Miller, N.L.

2011-01-10T23:59:59.000Z

109

ELECTROMAGNETIC POLARIZATION IN PARTIALLY IONIZED PLASMAS WITH STRONG MAGNETIC FIELDS AND NEUTRON STAR ATMOSPHERE MODELS  

E-Print Network (OSTI)

of the relatively high atmosphere density, a proper treatment should take account of the plasma nonidealityELECTROMAGNETIC POLARIZATION IN PARTIALLY IONIZED PLASMAS WITH STRONG MAGNETIC FIELDS AND NEUTRON STAR ATMOSPHERE MODELS Alexander Y. Potekhin,1, 2 Dong Lai,3 Gilles Chabrier,4 and Wynn C. G. Ho5, 6

110

Observed Scaling in Clouds and Precipitation and Scale Incognizance in Regional to Global Atmospheric Models  

SciTech Connect

We use observations of robust scaling behavior in clouds and precipitation to derive constraints on how partitioning of precipitation should change with model resolution. Our analysis indicates that 90-99% of stratiform precipitation should occur in clouds that are resolvable by contemporary climate models (e.g., with 200 km or finer grid spacing). Furthermore, this resolved fraction of stratiform precipitation should increase sharply with resolution, such that effectively all stratiform precipitation should be resolvable above scales of ~50 km. We show that the Community Atmosphere Model (CAM) and the Weather Research and Forecasting (WRF) model also exhibit the robust cloud and precipitation scaling behavior that is present in observations, yet the resolved fraction of stratiform precipitation actually decreases with increasing model resolution. A suite of experiments with multiple dynamical cores provides strong evidence that this `scale-incognizant' behavior originates in one of the CAM4 parameterizations. An additional set of sensitivity experiments rules out both convection parameterizations, and by a process of elimination these results implicate the stratiform cloud and precipitation parameterization. Tests with the CAM5 physics package show improvements in the resolution-dependence of resolved cloud fraction and resolved stratiform precipitation fraction.

O'Brien, Travis A.; Li, Fuyu; Collins, William D.; Rauscher, Sara; Ringler, Todd; Taylor, Mark; Hagos, Samson M.; Leung, Lai-Yung R.

2013-12-01T23:59:59.000Z

111

Improving the Representation of the Physical Atmosphere in Central California Using Satellite Data  

E-Print Network (OSTI)

constrained by observations. Moisture, Heat Capacity, Solar Radiation from Satellite Observations #12; EGHRImproving the Representation of the Physical Atmosphere in Central California Using Satellite Data/22/2006 8/23/2006 8/24/2006 Date Agreementindex(fraction) AI_cntrl AI_assim W0 #12;Central California

Jacob, Daniel J.

112

An Update on Radiative Transfer Model Development at Atmospheric and Environmental Research, Inc.  

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

Update on Radiative Transfer Model Development at Update on Radiative Transfer Model Development at Atmospheric and Environmental Research, Inc. J. S. Delamere, S. A. Clough, E. J. Mlawer, Sid-Ahmed Boukabara, K. Cady-Pereira, and M. Shepard Atmospheric and Environmental Research, Inc. Lexington, Maine Introduction Over the last decade, a suite of radiative transfer models has been developed at Atmospheric and Environmental Research, Inc. (AER) with support from the Atmospheric and Radiation Measurement (ARM) Program. These models span the full spectral regime from the microwave to the ultraviolet, and range from monochromatic to band calculations. Each model combines the latest spectroscopic advancements with radiative transfer algorithms to efficiently compute radiances, fluxes, and cooling

113

Open problem: Dynamic Relational Models for Improved Hazardous Weather Prediction  

E-Print Network (OSTI)

. Current weather radar detection and prediction sys- tems primarily rely on numerical models. We proposeOpen problem: Dynamic Relational Models for Improved Hazardous Weather Prediction Amy McGovern1, #12;Dynamic Relational Models for Improved Hazardous Weather Prediction Radar velocity Radar

McGovern, Amy

114

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

SciTech Connect

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

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

2006-08-04T23:59:59.000Z

115

The Landfall and Inland Penetration of a Flood-Producing Atmospheric River in Arizona. Part II: Sensitivity of Modeled Precipitation to Terrain Height and Atmospheric River Orientation  

Science Journals Connector (OSTI)

This manuscript documents numerical modeling experiments based on a January 2010 atmospheric river (AR) event that caused extreme precipitation in Arizona. The control experiment (CNTL), using the Weather Research and Forecasting (WRF) Model with ...

Mimi Hughes; Kelly M. Mahoney; Paul J. Neiman; Benjamin J. Moore; Michael Alexander; F. Martin Ralph

2014-10-01T23:59:59.000Z

116

Graduate Opportunities in Atmospheric Modeling to Understand Greenhouse Gas Emissions  

E-Print Network (OSTI)

and energy infrastructure. The graduate projects, fully funded by the National Oceanic and Atmospheric greenhouse gas emissions. Samples of guiding questions as part of the projects include: � What can explain; (3) demonstrated computer skills (e.g., Linux, R, Matlab, Fortran, GIS); (4) excellent oral

Lin, John Chun-Han

117

The OceanLandAtmosphere Model: Optimization and Evaluation of Simulated Radiative Fluxes and Precipitation  

Science Journals Connector (OSTI)

This work continues the presentation and evaluation of the OceanLandAtmosphere Model (OLAM), focusing on the models ability to represent radiation and precipitation. OLAM is a new, state-of-the-art earth system model, capable of user-specified ...

David Medvigy; Robert L. Walko; Martin J. Otte; Roni Avissar

2010-05-01T23:59:59.000Z

118

Toward a Fully Lagrangian Atmospheric Modeling System JAHRUL M. ALAM AND JOHN C. LIN  

E-Print Network (OSTI)

weather prediction (NWP) models]. A better numerical treatment of the nonlinear advection process numerical model is, therefore, presented for calculating atmospheric flows. The model employs a Lagrangian). Such models require numerical simu- lation of advection-dominated flow problems. The re- alization

Lin, John Chun-Han

119

Data Collection for Improved Cold Temperature Thermal Modeling...  

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

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

120

A modified formulation of fractional stratiform condensation rate in the NCAR Community Atmospheric Model (CAM2)  

E-Print Network (OSTI)

Sciences, University of Washington, Seattle, Washington, USA James J. Hack and Phillip J. Rasch National, Community Atmospheric Model (CAM) Citation: Zhang, M., W. Lin, C. Bretherton, J. Hack, and P. J. Rasch

Zhang, Minghua

Note: This page contains sample records for the topic "improving atmospheric models" 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

Ensemble regression : using ensemble model output for atmospheric dynamics and prediction  

E-Print Network (OSTI)

Ensemble regression (ER) is a linear inversion technique that uses ensemble statistics from atmospheric model output to make dynamical inferences and forecasts. ER defines a multivariate regression operator using ensemble ...

Gombos, Daniel (Daniel Lawrence)

2009-01-01T23:59:59.000Z

122

Modeling the Atmospheric Boundary Layer Wind Response to Mesoscale Sea Surface Temperature Perturbations  

Science Journals Connector (OSTI)

The wind speed response to mesoscale SST variability is investigated over the Agulhas Return Current region of the Southern Ocean using the Weather Research and Forecasting (WRF) Model and the U.S. Navy Coupled OceanAtmosphere Mesoscale ...

Natalie Perlin; Simon P. de Szoeke; Dudley B. Chelton; Roger M. Samelson; Eric D. Skyllingstad; Larry W. ONeill

2014-11-01T23:59:59.000Z

123

Numerical Modeling of the Propagation Environment in the Atmospheric Boundary Layer over the Persian Gulf  

Science Journals Connector (OSTI)

Strong vertical gradients at the top of the atmospheric boundary layer affect the propagation of electromagnetic waves and can produce radar ducts. A three-dimensional, time-dependent, nonhydrostatic numerical model was used to simulate the ...

B. W. Atkinson; J-G. Li; R. S. Plant

2001-03-01T23:59:59.000Z

124

Accelerated Iterative Method for Solving Steady Solutions of Linearized Atmospheric Models  

E-Print Network (OSTI)

Accelerated Iterative Method for Solving Steady Solutions of Linearized Atmospheric Models Masahiro approach, referred to as the accelerated iterative method (AIM), is developed for solving steady state, respectively. For ensuring the accelerated asymptotic convergence of iterative procedure

Watanabe, Masahiro

125

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

E-Print Network (OSTI)

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

Covey, Curt

126

E-Print Network 3.0 - atmospheric pollutant modeling Sample Search...  

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

Sample search results for: atmospheric pollutant modeling Page: << < 1 2 3 4 5 > >> 1 Air Pollution Physics and Chemistry EAS 6790 Monday, Wednesday, Friday 2:05 to 2:55...

127

Understanding El Nio in OceanAtmosphere General Circulation Models: Progress and Challenges  

Science Journals Connector (OSTI)

Determining how El Nio and its impacts may change over the next 10 to 100 years remains a difficult scientific challenge. Oceanatmosphere coupled general circulation models (CGCMs) are routinely used both to analyze El Nio mechanisms and ...

Eric Guilyardi; Andrew Wittenberg; Alexey Fedorov; Mat Collins; Chunzai Wang; Antonietta Capotondi; Geert Jan van Oldenborgh; Tim Stockdale

2009-03-01T23:59:59.000Z

128

Spatial Variation of Soil Type and Soil Moisture in the Regional Atmospheric Modeling System  

SciTech Connect

Soil characteristics (texture and moisture) are typically assumed to be initially constant when performing simulations with the Regional Atmospheric Modeling System (RAMS). Soil texture is spatially homogeneous and time-independent, while soil moisture is often spatially homogeneous initially, but time-dependent. This report discusses the conversion of a global data set of Food and Agriculture Organization (FAO) soil types to RAMS soil texture and the subsequent modifications required in RAMS to ingest this information. Spatial variations in initial soil moisture obtained from the National Center for Environmental Predictions (NCEP) large-scale models are also introduced. Comparisons involving simulations over the southeastern United States for two different time periods, one during warmer, more humid summer conditions, and one during cooler, dryer winter conditions, reveals differences in surface conditions related to increases or decreases in near-surface atmospheric moisture con tent as a result of different soil properties. Three separate simulation types were considered. The base case assumed spatially homogeneous soil texture and initial soil moisture. The second case assumed variable soil texture and constant initial soil moisture, while the third case allowed for both variable soil texture and initial soil moisture. The simulation domain was further divided into four geographically distinct regions. It is concluded there is a more dramatic impact on thermodynamic variables (surface temperature and dewpoint) than on surface winds, and a more pronounced variability in results during the summer period. While no obvious trends in surface winds or dewpoint temperature were found relative to observations covering all regions and times, improvement in surface temperatures in most regions and time periods was generally seen with the incorporation of variable soil texture and initial soil moisture.

Buckley, R.

2001-06-27T23:59:59.000Z

129

Estimation of errors in the inverse modeling of accidental release of atmospheric pollutant: Application to the reconstruction  

E-Print Network (OSTI)

Estimation of errors in the inverse modeling of accidental release of atmospheric pollutant difficulty when inverting the source term of an atmospheric tracer dispersion problem is the estimation of the prior errors: those of the atmospheric transport model, those ascribed to the representativity

Paris-Sud XI, Université de

130

EMSL: Science: Atmospheric Aerosol Systems  

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

Atmospheric Aerosol Systems Atmospheric Aerosol Systems atmospheric logo Nighttime enhancement of nitrogen-containing organic compounds, or NOC Observed nighttime enhancement of nitrogen-containing organic compounds, or NOC, showed evidence of being formed by reactions that transform carbonyls into imines. The Atmospheric Aerosol Systems Science Theme focuses on understanding the chemistry, physics and molecular-scale dynamics of aerosols for model parameterization to improve the accuracy of climate model simulations and develop a predictive understanding of climate. By elucidating the role of natural and anthropogenic regional and global climate forcing mechanisms, EMSL can provide DOE and others with the ability to develop cost-effective strategies to monitor, control and mitigate them.

131

A spectral transform dynamical core option within the Community Atmosphere Model (CAM4)  

SciTech Connect

A spectral transform dynamical core with an 85 spectral truncation resolution (T85) within the Community Atmosphere Model (CAM), version 4, is evaluated within the recently released Community Earth System Model, version 1.0 (CESM) global climate model. The spectral dynamical core option provides a well-known base within the climate model community from which to assess climate behavior and statistics, and its relative computational efficiency for smaller computing platforms allows it to be extended to perform climate length simulations using high-resolution configurations in the near term. To establish the characteristics of the CAM4 T85, an ensemble of simulations covering the present day observational period using forced sea surface temperatures and prescribed sea-ice extent are evaluated. Overall, the T85 ensemble attributes and biases are similar to a companion ensemble of simulations using the one degree finite volume (FV1) dynamical core, relative to observed and model derived datasets. Notable improvements with T85 compared to FV1 include the representation of wintertime Arctic sea level pressure and summer precipitation over the Western Indian subcontinent. The mean and spatial patterns of the land surface temperature trends over the AMIP period are generally well simulated with the T85 ensemble relative to observations, however the model is not able to capture the extent nor magnitude of changes in temperature extremes over the boreal summer, where the changes are most dramatic. Biases in the wintertime Arctic surface temperature and annual mean surface stress fields persist with T85 as with the CAM3 version of T85.

Evans, Katherine J [ORNL; Mahajan, Salil [ORNL; Branstetter, Marcia L [ORNL; McClean, Julie L. [Scripps Institute of Oceanography; Caron, Julie M. [National Center for Atmospheric Research (NCAR); Maltrud, Matthew E. [Los Alamos National Laboratory (LANL); Hack, James J [ORNL; Bader, David C [ORNL; Neale, Rich [National Center for Atmospheric Research (NCAR)

2014-01-01T23:59:59.000Z

132

Initial atmospheric-dispersion modeling in support of the multiple-site incineration study  

SciTech Connect

Several modeling series which estimate population exposure to stack emissions from incineration of hazardous organic materials at 22 commercial incinerator sites are presented. These modeling series can be divided into three groups. One group estimates long- and short-term atmospheric concentrations and population exposures for each of 22 sites. These modeling predictions can be used to assess chronic and acute exposure. The second group consists of sensitivity analyses which show the effect of changes in stack parameters on the number of people exposed to specified concentration levels. The third group compares concentration estimates of two atmospheric dispersion computer codes. Results of each modeling series are contained in the appendices of this report.

Holton, G.A.; Little, C.A.; O& #x27; Donnell, F.R.; Etnier, E.L.; Travis, C.C.

1982-04-01T23:59:59.000Z

133

Transformer Thermal Modeling: Improving Reliability Using Data Quality Control  

E-Print Network (OSTI)

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

134

Improved diagnostic model for estimating wind energy  

SciTech Connect

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

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

1983-03-01T23:59:59.000Z

135

Modeling of the optical properties of nonspherical particles in the atmosphere  

E-Print Network (OSTI)

, Richard Orville August 2007 Major Subject: Atmospheric Sciences iii ABSTRACT Modeling of the Optical Properties of Nonspherical Particles in the Atmosphere. (August 2007) Guang Chen, B.S., Jilin University; M.S., University of Southern... [49]. However, the PSTD method applies a centered grid scheme that specifies all field components at the centers of the grid cells, as shown in Fig. A.2b. Because of this advantage, the PSTD algorithm is significantly simplified, particularly...

Chen, Guang

2009-05-15T23:59:59.000Z

136

Prediction of Ice Crystal Number in Community Atmospheric Model (CAM3.0)  

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

Prediction of Ice Crystal Number in Community Atmospheric Model (CAM3.0) Prediction of Ice Crystal Number in Community Atmospheric Model (CAM3.0) Liu, Xiaohong Pacific Northwest National Laboratory Ghan, Steven Pacific Northwest National Laboratory Wang, M University of Michigan Penner, Joyce University of Michigan Category: Modeling A prognostic equation of ice crystal number concentrations is implemented in the Community Atmospheric Model (CAM3.0) with the aim to study the aerosol effects on climate through changing the ice cloud properties. The microphysical processes affecting the ice number concentration include ice nucleation, secondary production of crystals, and the conversion of ice to snow. For ice nucleation process, Liu and Penner (2005) parameterization of homogeneous nucleation of sulfate and heterogeneous immersion nucleation on

137

The solar photospheric abundance of phosphorus: results from co5bold 3D model atmospheres  

E-Print Network (OSTI)

aims: We determine the solar abundance of phosphorus using co5bold 3D hydrodynamic model atmospheres. method: High resolution, high signal-to-noise solar spectra of the PI lines of Multiplet 1 at 1051-1068 nm are compared to line formation computations performed on a co5bold solar model atmosphere. results: We find A(P)=5.46+- 0.04, in good agreement with previous analysis based on 1D model atmospheres, due to the fact that the PI lines of Mult. 1 are little affected by 3D effects. We cannot confirm an earlier claim by other authors of a downward revision of the solar P abundance by 0.1 dex employing a 3D model atmosphere. Concerning other stars, we found modest (<0.1 dex) 3D abundance corrections for P among four F dwarf model atmospheres of different metallicity, being largest at lowest metallicity. conclusions: We conclude that 3D abundance corrections are generally rather small for the PI lines studied in this work. They are marginally relevant for metal-poor stars, but may be neglected in the Sun.

Elisabetta Caffau; Matthias Steffen; Luca Sbordone; Hans-G. Ludwig; Piercarlo Bonifacio

2007-08-12T23:59:59.000Z

138

Atmospheric Environment 42 (2008) 37513764 Modeling the effects of ship emissions on coastal air quality  

E-Print Network (OSTI)

Atmospheric Environment 42 (2008) 3751­3764 Modeling the effects of ship emissions on coastal air emissions, they could have important environmental effects on coastal areas near ports with heavy ship-going ships on ozone and particulate matter concentrations is quantified using UCI- CIT model for the South

Dabdub, Donald

139

Time Step Sensitivity of Nonlinear Atmospheric Models: Numerical Convergence, Truncation Error Growth, and Ensemble Design  

E-Print Network (OSTI)

1973; Oran and Boris 1987; Murray 1989; Gershenfeld 1999). Weather and climate prediction models, which to the initial conditions, which is a major source of uncertainty in Numerical Weather Prediction (NWP; eTime Step Sensitivity of Nonlinear Atmospheric Models: Numerical Convergence, Truncation Error

Judd, Kevin

140

Improved computer models support genetics research  

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

February » February » Simple computer models unravel genetic stress reactions in cells Simple computer models unravel genetic stress reactions in cells Integrated biological and computational methods provide insight into why genes are activated. February 8, 2013 When complete, these barriers will be a portion of the NMSSUP upgrade. This molecular structure depicts a yeast transfer ribonucleic acid (tRNA), which carries a single amino acid to the ribosome during protein construction. A combined experimental and computational approach, to better understand signaling pathways that lead to genetic mutations, is at the core of this research. Contact thumbnail of Brian Munsky, PhD Distinguished Postdoctoral Fellow Brian Munsky, PhD Information Services, Advanced Measurement Science

Note: This page contains sample records for the topic "improving atmospheric models" 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

O3-NOx-VOC sensitivity and NOx-VOC indicators in Paris: Results from models and Atmospheric Pollution Over  

E-Print Network (OSTI)

from the Atmospheric Pollution Over the Paris Area campaign near Paris, with special attention Composition and Structure: Pollution--urban and regional (0305); 0365 Atmospheric Composition and Structure-VOC indicators in Paris: Results from models and Atmospheric Pollution Over the Paris Area (ESQUIF) measurements

Menut, Laurent

142

Construction Logistics Improvements using the SCOR model Tornet Case  

E-Print Network (OSTI)

Construction Logistics Improvements using the SCOR model �Tornet Case Fredrik Persson1 , Jonas are emerging that leads to cost reductions in construction. In this strive towards improvement, logistics on cost savings from the logistics perspective in different areas of the logistic system. Keywords

Paris-Sud XI, Université de

143

Scaling turbulent atmospheric stratification: a turbulence/wave wind model  

E-Print Network (OSTI)

, it displays no wave-like phenomenol- ogy. We show how to extend the FIF model to account for more realistic

Lovejoy, Shaun

144

ORNL researchers improve soil carbon cycling models | ornl.gov  

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

researchers improve soil carbon cycling models researchers improve soil carbon cycling models January 01, 2013 ORNL's new carbon cycling model could help scientists understand the role of soil microbes (MBC) in climate change by tracking extracellular enzymes (ENZ) that break down carbon-rich soil materials (SOC) into forms that microbes can respire (DOC). A more robust model of the soil carbon cycle developed at Oak Ridge National Laboratory (ORNL) improves understanding of carbon residence time in soils and enables scientists to make more accurate climate predictions. The model does a better job than previous models of accounting for how microbes in the soil break down carbon-rich materials and release carbon dioxide. "Soil is a big reservoir of carbon," said co-author Melanie Mayes of the Environmental Sciences Division and the Climate Change Science

145

BISON Enhanced with Improved Models for Cladding and Coolant Channels |  

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

Enhanced with Improved Models for Cladding and Coolant Enhanced with Improved Models for Cladding and Coolant Channels BISON Enhanced with Improved Models for Cladding and Coolant Channels January 29, 2013 - 10:54am Addthis Pin-scale Code Development Development of BISON for the engineering-scale simulation of nuclear fuel performance continued. Enhancements during this quarter include implementation of a nonlinear material model for Zircaloy cladding that simultaneously combines the phenomena of plasticity, thermal creep, and irradiation creep; implementation of a complete set of material properties and a creep model for stainless steel cladding; and modification of the coolant sub-channel model to better support simulations of loss-of- coolant-accidents. BISON simulations are being compared to relevant empirical fuel pin data

146

Combining Modeling Methodologies for Improved Understanding of Smart Material Characteristics  

E-Print Network (OSTI)

Combining Modeling Methodologies for Improved Understanding of Smart Material Characteristics Material Systems and Structures February 2, 1998 ABSTRACT Smart materials are complex materials performance capabilities but the synergistic response of the smart material and companion structure. Behavior

Lindner, Douglas K.

147

Coupled AtmosphereWildland Fire Modelling Jean Baptiste Filippi1  

E-Print Network (OSTI)

to the estimation of the rate of spread of the fire. Wildfire's convection (i.e., entire plume) can modify the local localized extreme events. These models have been selected because they can be run coupled and support model used in ForeFire provides a physical formulation to take into account the effect of wind and slope

Clements, Craig

148

Improved load models for multi-area reliability calculations  

E-Print Network (OSTI)

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

Pathak, Sanjesh

1992-01-01T23:59:59.000Z

149

Transient Response of the Hadley Centre Coupled Ocean-Atmosphere Model to Increasing Carbon Dioxide. Part III: Analysis of Global-Mean Response Using Simple Models  

Science Journals Connector (OSTI)

The roles of surface, atmospheric, and oceanic feedbacks in controlling the global-mean transient response of a coupled ocean-atmosphere general circulation model to increasing carbon dioxide are investigated. The analysis employs a four-box ...

J. M. Murphy

1995-03-01T23:59:59.000Z

150

Simulation and modeling of atmospheric fluidized bed combustors for high sulfur coals  

SciTech Connect

The principal issues in modeling atmospheric fluidized bed combustors (AFBC) are described using the Oak Ridge National Laboratory (ORNL) - Tennessee Valley Authority (TVA) steady state AFBC model as an example. Comparisons are made between model predictions of boiler performance with experimental data from the TVA 20 MW(e) AFBC pilot plant data. Recent FBC models are briefly reviewed and compared with the ORNL-TVA model. The paper also describes the ongoing effort at TVA on transient modeling of AFBC and presents some preliminary results from the TVA AFBC transient model.

Krishnan, R.P.; Daw, C.S.; Byrd, J.; Zielke, R.; Wells, J.W.

1986-01-01T23:59:59.000Z

151

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

SciTech Connect

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

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

2013-07-15T23:59:59.000Z

152

A grid of synthetic ionizing spectra for very hot compact stars from NLTE model atmospheres  

E-Print Network (OSTI)

The precise analysis of properties of planetary nebulae is strongly dependent on good models for the stellar ionizing spectrum. Observations in the UV - X-ray wavelength range as well as NLTE model atmosphere calculations of spectra of their exciting stars have shown that neither blackbody fluxes nor "standard" NLTE atmosphere models which are composed out of hydrogen and helium only are good approximations. Strong differences between synthetic spectra from these compared to observed spectra at energies higher than 54 eV (He II ground state) can be ascribed to the neglect of metal-line blanketing. Realistic modeling of the emergent fluxes of hot stars in the UV - X-ray wavelength range requires metal-line blanketed NLTE model atmospheres which include all elements from hydrogen up to the iron-group. For this purpose, we present a grid (solar and halo abundance ratios) of metal-line blanketed NLTE model atmosphere fluxes which covers the parameter range of central stars of planetary nebulae.

Thomas Rauch

2003-03-20T23:59:59.000Z

153

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

E-Print Network (OSTI)

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

Friedman, Carey

154

MODELING ATMOSPHERIC RELEASES OF TRITIUM FROM NUCLEAR INSTALLATIONS  

SciTech Connect

Tritium source term analysis and the subsequent dispersion and consequence analyses supporting the safety documentation of Department of Energy nuclear facilities are especially sensitive to the applied software analysis methodology, input data and user assumptions. Three sequential areas in tritium accident analysis are examined in this study to illustrate where the analyst should exercise caution. Included are: (1) the development of a tritium oxide source term; (2) use of a full tritium dispersion model based on site-specific information to determine an appropriate deposition scaling factor for use in more simplified, broader modeling, and (3) derivation of a special tritium compound (STC) dose conversion factor for consequence analysis, consistent with the nature of the originating source material. It is recommended that unless supporting, defensible evidence is available to the contrary, the tritium release analyses should assume tritium oxide as the species released (or chemically transformed under accident's environment). Important exceptions include STC situations and laboratory-scale releases of hydrogen gas. In the modeling of the environmental transport, a full phenomenology model suggests that a deposition velocity of 0.5 cm/s is an appropriate value for environmental features of the Savannah River Site. This value is bounding for certain situations but non-conservative compared to the full model in others. Care should be exercised in choosing other factors such as the exposure time and the resuspension factor.

Okula, K

2007-01-17T23:59:59.000Z

155

Agriculture model development to improve performance of the Community Land  

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

Agriculture model development to improve performance of the Community Land Agriculture model development to improve performance of the Community Land Model April 3, 2013 The important relationships between climate change and agriculture are uncertain, particularly the feedbacks related to the carbon cycle. Nevertheless, vegetation models have not yet considered the full impacts of management practices and nitrogen feedbacks on the carbon cycle. We are working to meet this need. We have integrated three crop types (corn, soybean, and spring wheat) into the Community Land Model (CLM). In developing the agriculture version of CLM, we added plant processes related to management practices and nitrogen cycling. A manuscript documenting our changes to CLM has been accepted for publication in Geoscientific Model Development Discussions ("Modeling

156

A Flexible Atmospheric Modeling Framework for the CESM  

SciTech Connect

We have created two global dynamical cores based on the unified system of equations and Z-grid staggering on an icosahedral grid, which are collectively called UZIM (Unified Z-grid Icosahedral Model). The z-coordinate version (UZIM-height) can be run in hydrostatic and nonhydrostatic modes. The sigma-coordinate version (UZIM-sigma) runs in only hydrostatic mode. The super-parameterization has been included as a physics option in both models. The UZIM versions with the super-parameterization are called SUZI. With SUZI-height, we have completed aquaplanet runs. With SUZI-sigma, we are making aquaplanet runs and realistic climate simulations. SUZI-sigma includes realistic topography and a SiB3 model to parameterize the land-surface processes.

Randall, David [Colorado State University; Heikes, Ross [Colorado State University; Konor, Celal [Colorado State University

2014-11-12T23:59:59.000Z

157

USING NETWORKS OF JOURNEYS TO IMPROVE A PETROL MARKET MODEL  

E-Print Network (OSTI)

USING NETWORKS OF JOURNEYS TO IMPROVE A PETROL MARKET MODEL Alison Heppenstall1 , Andrew Evans1 that the majority of consumers purchased petrol on their way to work or on shopping trips. A network model at the micro level are not tied to global level variables like oil prices); the parameters are often difficult

Clark, Joanna

158

Improvement of ENSO simulation based on inter-model diversity  

Science Journals Connector (OSTI)

In this study, a new methodology is developed to improve the climate simulation of state-of-the-art coupled Global Climate Models (GCMs), by a post-processing based on the inter-model diversity. Based on the close connection between the ...

Yoo-Geun Ham; Jong-Seong Kug

159

IMPROVEMENTS IN MODELLING DISSOLVED OXYGEN IN ACTIVATED SLUDGE SYSTEMS  

E-Print Network (OSTI)

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

Wells, Scott A.

160

RESEARCH ARTICLE A model for improving microbial biofuel production using  

E-Print Network (OSTI)

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

Dunlop, Mary

Note: This page contains sample records for the topic "improving atmospheric models" 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

Diagnostics for near-surface wind response to the Gulf Stream in a regional atmospheric model  

Science Journals Connector (OSTI)

The mechanisms acting on near-surface winds over the Gulf Stream are diagnosed using 5-year outputs of a regional atmospheric model. The diagnostics for the surface-layer momentum vector, its curl, and its convergence are developed with a clear ...

Kohei Takatama; Shoshiro Minobe; Masaru Inatsu; R. Justin Small

162

Measurements and modelling of atmospheric pollution over the Paris area: an overview of the ESQUIF Project  

E-Print Network (OSTI)

dedicated to the study of the processes leading to air pollution events over the Paris area. The project, pollution levels in the Paris area due to concentrated activity have become a major health issue. CurrentMeasurements and modelling of atmospheric pollution over the Paris area: an overview of the ESQUIF

Paris-Sud XI, Université de

163

Block-structured adaptive meshes and reduced grids for atmospheric general circulation models  

Science Journals Connector (OSTI)

...semi-Lagrangian shallow-water model on locally refined...Higgins1990Integration of the shallow water equations on the sphere...parallel adaptive mesh generator for atmospheric and oceanic simulationOcean...series to the shallow-water equations on sphereJ...

2009-01-01T23:59:59.000Z

164

Modeling atmospheric effects of the September 1859 solar flare B. C. Thomas,1  

E-Print Network (OSTI)

the production of odd hydrogen- and nitrogen-oxides. Production of HOx (e.g., H, OH, HO2) and NOy (e.g., N, NO showing production of odd nitrogen compounds and their impact on ozone. We also compute rainout of nitrate. Methods [4] Our modeling was performed using the Goddard Space Flight Center two-dimensional atmospheric

Jackman, Charles H.

165

Laboratory modelling of atmospheric dynamical processes J. Sommeria and H. Didelle  

E-Print Network (OSTI)

of cars or airplanes is commonly tested in wind tunnels. The wake of ships and the impact of waves in the Giant planet atmosphere. Finally examples of topographic wakes in a stratified fluid and gravity of field measurements. For instance validation of a model by observations in the present climatic

Paris-Sud XI, Université de

166

MEASUREMENT AND MODELLING OF AMMONIA EMISSIONS AT WASTE TREATMENT LAGOON-ATMOSPHERIC INTERFACE  

E-Print Network (OSTI)

- izers, emission from soils, biomass burning, and domestic animal waste (Bouwman et al., 1997MEASUREMENT AND MODELLING OF AMMONIA EMISSIONS AT WASTE TREATMENT LAGOON-ATMOSPHERIC INTERFACE animals ( 32 Tg N -1yr-1). Waste storage and treatment lagoons are used to treat the excreta of hogs

Aneja, Viney P.

167

Hybrid fluid/kinetic modeling of Pluto's escaping atmosphere Justin Erwin a,  

E-Print Network (OSTI)

with the solar wind at the New Horizon encounter. For the parameter space covered, we also find an inverse exploration of the planets and moons in our solar system and the rapid increase in the discovery of exoplanetsHybrid fluid/kinetic modeling of Pluto's escaping atmosphere Justin Erwin a, , O.J. Tucker b

Johnson, Robert E.

168

Modelled and observed variability of the atmospheric circulation the Peruvian Current System: 2000-2005  

E-Print Network (OSTI)

on the characteristics of the local equatorward atmospheric circulation. Resolving the mesoscale variability of the heat Mesoscale Model (MM5) and Weather Research and Forecasting (WRF) that were run over the Peruvian Current System (PCS) [0N-19°S; 83°W-68°W] from November 2000- October 2005. Wind data as derived from

169

An Improved Simple Chilled Water Cooling Coil Model  

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

An Improved Simple Chilled Water Cooling Coil Model An Improved Simple Chilled Water Cooling Coil Model Title An Improved Simple Chilled Water Cooling Coil Model Publication Type Conference Paper LBNL Report Number LBNL-6031E Year of Publication 2012 Authors Wang, Liping, Philip Haves, and Walter F. Buhl Conference Name SimBuild 2012 IBPSA Conference Date Published 08/2012 Abstract The accurate prediction of cooling and dehumidification coil performance is important in model-based fault detection and in the prediction of HVAC system energy consumption for support of both design and operations. It is frequently desirable to use a simple cooling coil model that does not require detailed specification of coil geometry and material properties. The approach adopted is to match the overall UA of the coil to the rating conditions and to estimate the air-side and water-side components of the UA using correlations developed by Holmes (1982). This approach requires some geometrical information about the coil and the paper investigates the sensitivity of the overall performance prediction to uncertainties in this information, including assuming a fixed ratio of air-side to water-side UA at the rating condition. Finally, simulation results from different coil models are compared, and experimental data are used to validate the improved cooling coil model.

170

Model atmospheres for novae during the early stages  

SciTech Connect

Continuum and line blanketing models for the photospheres of novae in the early stages of their outbursts are presented. The expanding envelopes are characterized by a very slow increase of density with decreasing radius which leads to very large geometrical extensions and large temperature differences between the inner and outer parts. The spectra show a large IR excess and a small Balmer jump which may be either in absorption or in emission. For the parameters considered (T{sub eff} = 10{sup 4}, 1.5 {times} 10{sup 4}, 2 {times} 10{sup 4}K, R = 10{sup 11} cm, solar composition), most lines are in absorption. The effects of both modifications in the temperature structure (e.g. by heating from shock fronts) and changes in the abundances of the heavy elements on the emergent spectra are briefly discussed. 13 refs., 11 figs.

Wehrse, R.; Hauschildt, P.H. (Heidelberg Univ. (Germany, F.R.). Inst. fuer Theoretische Astrophysik); Shaviv, G. (Technion-Israel Inst. of Tech., Haifa (Israel). Dept. of Physics); Starrfield, S. (Los Alamos National Lab., NM (USA) Arizona State Univ., Tempe, AZ (USA). Dept. of Physics)

1989-01-01T23:59:59.000Z

171

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

E-Print Network (OSTI)

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

Laitner, J. A.

2007-01-01T23:59:59.000Z

172

Electromagnetic polarization in partially ionized plasmas with strong magnetic fields and neutron star atmosphere models  

E-Print Network (OSTI)

Polarizability tensor of a strongly magnetized plasma and the polarization vectors and opacities of normal electromagnetic waves are studied for the conditions typical of neutron star atmospheres, taking account of partial ionization effects. Vacuum polarization is also included using a new set of fitting formulae that are accurate for wide range of field strengths. The full account of the coupling of the quantum mechanical structure of the atoms to their center-of-mass motion across the magnetic field is shown to be crucial for the correct evaluation of the polarization properties and opacities of the plasma. The self-consistent treatment of the polarizability and absorption coefficients proves to be necessary if the ionization degree of the plasma is low, which can occur in the atmospheres of cool or ultramagnetized neutron stars. Atmosphere models and spectra are presented to illustrate the importance of such self-consistent treatment.

A. Y. Potekhin; Dong Lai; G. Chabrier; W. C. G. Ho

2004-05-20T23:59:59.000Z

173

Assimilation of observations of radiation level into an atmospheric transport model: A case study with the particle filter and the ETEX tracer dataset  

Science Journals Connector (OSTI)

Atmospheric transport models and observations from monitoring networks are commonly used aids for forecasting spatial distribution of contamination in case of a radiological incident. In this study, we assessed the particle filter data-assimilation technique as a tool for ensemble forecasting the spread of radioactivity. We used measurements from the ETEX-1 tracer experiment and model results from the NPK-Puff atmospheric dispersion model. We showed that assimilation of observations improves the ensemble forecast compared to runs without data assimilation. The improvement is most prominent for nowcasting: the mean squared error was reduced by a factor of 7. For forecasting, the improvement of the mean squared error resulting from assimilation of observations was found to dissipate within a few hours. We ranked absolute model values and observations and calculated the mean squared error of the ranked values. This measure of the correctness of the pattern of high and low values showed an improvement for forecasting up to 48h. We conclude that the particle filter is an effective tool in better modeling the spread of radioactivity following a release.

Paul H. Hiemstra; Derek Karssenberg; Arjan van Dijk

2011-01-01T23:59:59.000Z

174

Earth and Atmospheric Sciences | More Science | ORNL  

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

Nuclear Forensics Climate & Environment Sensors and Measurements Chemical & Engineering Materials Computational Earth Science Systems Modeling Geographic Information Science and Technology Materials Science and Engineering Mathematics Physics More Science Home | Science & Discovery | More Science | Earth and Atmospheric Sciences SHARE Earth and Atmospheric Sciences At ORNL, we combine our capabilities in atmospheric science, computational science, and biological and environmental systems science to focus in the cross-disciplinary field of climate change science. We use computer models to improve climate change predications and to measure the impact of global warming on the cycling of chemicals in earth systems. Our Climate Change Science Institute uses models to explore connections among atmosphere,

175

A Model-Based Decomposition of the Sea IceAtmosphere Feedback over the Barents Sea during Winter  

Science Journals Connector (OSTI)

The feedback between Barents Sea ice and the winter atmosphere was studied in a modeling framework by decomposing it into two sequential boundary forcing experiments. The Community Ice Code (CICE) model was initialized with anomalously high sea ...

Jessica Liptak; Courtenay Strong

2014-04-01T23:59:59.000Z

176

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

E-Print Network (OSTI)

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

Wegner, T.

177

High Resolution Transmission Spectroscopy as a Diagnostic for Jovian Exoplanet Atmospheres: Constraints from Theoretical Models  

E-Print Network (OSTI)

We present high resolution transmission spectra of giant planet atmospheres from a coupled 3-D atmospheric dynamics and transmission spectrum model that includes Doppler shifts which arise from winds and planetary motion. We model jovian planets covering more than two orders of magnitude in incident flux, corresponding to planets with 0.9 to 55 day orbital periods around solar-type stars. The results of our 3-D dynamical models reveal certain aspects of high resolution transmission spectra that are not present in simple 1-D models. We find that the hottest planets experience strong substellar to anti-stellar (SSAS) winds, resulting in transmission spectra with net blue shifts of up to 3 km s$^{-1}$, whereas less irradiated planets show almost no net Doppler shifts. Compared to 1-D models, peak line strengths are significantly reduced for the hottest atmospheres owing to Doppler broadening from a combination of rotation (which is faster for close-in planets under the assumption of tidal locking) and atmospheri...

Kempton, Eliza M -R; Heng, Kevin

2014-01-01T23:59:59.000Z

178

MODELLING THE OVERLAND TRANSPORT OF LEAD DEPOSITED FROM THE ATMOSPHERE IN THE ELBE CATCHMENT OVER FOUR  

E-Print Network (OSTI)

unknown. Despite decreasing atmospheric pollution, soil and freshwater systems still indicate high lead on minimizing atmospheric emissions, but also on minimizing soil erosion. Keywords: atmospheric pollution, direct atmospheric deposition, direct runoff, Elbe catchment, erosion, soil pollution, lead, long

Costa-Cabral, Mariza

179

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

E-Print Network (OSTI)

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

Theodore E. Liolios

2003-06-23T23:59:59.000Z

180

Study of atmospheric pressure weakly ionized plasma as surface compatibilization technique for improved plastic composites loaded with cellulose based fillers .  

E-Print Network (OSTI)

??Atmospheric pressure plasmas have gained considerable interest from researchers recently for their unique prospective of engineering surfaces with plasma without the need of vacuum systems. (more)

[No author

2013-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "improving atmospheric models" 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

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

SciTech Connect

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

Morrison, PI Hugh

2012-09-21T23:59:59.000Z

182

Modeling of atmospheric-pressure plasma columns sustained by surface waves  

Science Journals Connector (OSTI)

A self-consistent two-dimensional fluid-plasma model coupled to Maxwells equations is presented for argon discharges sustained at atmospheric pressure by the propagation of an electromagnetic surface wave. The numerical simulation provides the full axial and radial structure of the surface-wave plasma column and the distribution of the electromagnetic fields for given discharge operating conditions. To describe the contraction phenomenon, a characteristic feature of high-pressure discharges, we consider the kinetics of argon molecular ions in the charged-particle balance. An original feature of the model is to take into account the gas flow by solving self-consistently the mass, momentum, and energy balance equations for neutral particles. Accounting for the gas flow explains reported discrepancies between measured and calculated plasma parameters when assuming the local axial uniformity approximation. In contrast to the low-pressure case, the latter approximation is shown to be of limited validity at atmospheric pressure. The gas temperature is found to be a key parameter in modeling surface-wave discharges sustained at atmospheric pressure. It determines the radial and the axial structure of the plasma column. The calculated plasma parameters and wave propagation characteristics using the present two-dimensional fluid model are in good agreement with our set of experimental data.

Y. Kabouzi; D. B. Graves; E. Castaos-Martnez; M. Moisan

2007-01-09T23:59:59.000Z

183

Models for close-in atmospheric dispersion, explosive releases, and particle deposition  

SciTech Connect

Relatively simple models are presented to simulate close-in atmospheric dispersion, explosive releases, and particle deposition. Close-in generally refers to distances less than 50 m downwind from the source. These models assume simple gas dispersion (no chemical reactions, neutral buoyancy) and that particles behave as a gas expect they can be removed from the plume by a simple, deposition-velocity mechanism. These models have been combined into a QuickBASIC program (INEXPLC.BAS) and its PC executable form (INEXPLC.EXE). These programs, along with sample input and output files, are available from the author.

Bloom, S.G.

1993-10-06T23:59:59.000Z

184

What causes the large extensions of red-supergiant atmospheres? Comparisons of interferometric observations with 1-D hydrostatic, 3-D convection, and 1-D pulsating model atmospheres  

E-Print Network (OSTI)

We present the atmospheric structure and the fundamental parameters of three red supergiants, increasing the sample of RSGs observed by near-infrared spectro-interferometry. Additionally, we test possible mechanisms that may explain the large observed atmospheric extensions of RSGs. We carried out spectro-interferometric observations of 3 RSGs in the near-infrared K-band with the VLTI/AMBER instrument at medium spectral resolution. To comprehend the extended atmospheres, we compared our observational results to predictions by available hydrostatic PHOENIX, available 3-D convection, and new 1-D self-excited pulsation models of RSGs. Our near-infrared flux spectra are well reproduced by the PHOENIX model atmospheres. The continuum visibility values are consistent with a limb-darkened disk as predicted by the PHOENIX models, allowing us to determine the angular diameter and the fundamental parameters of our sources. Nonetheless, in the case of V602 Car and HD 95686, the PHOENIX model visibilities do not predict ...

Arroyo-Torres, B; Chiavassa, A; Scholz, M; Freytag, B; Marcaide, J M; Hauschildt, P H; Wood, P R; Abellan, F J

2015-01-01T23:59:59.000Z

185

An Improved Land Surface Emissivity Parameter for Land Surface Models Using Global Remote Sensing Observations  

E-Print Network (OSTI)

Observations MENGLIN JIN Department of Atmospheric and Oceanic Science, University of Maryland, College Park Oceanic and Atmospheric Administration (NOAA) National Centers for Environmental Prediction (NCEP) model that the assumption of the constant emissivity induces errors in modeling the surface energy budget, especially over

Liang, Shunlin

186

Single-Column Modeling C. J. Walcek Atmospheric Sciences Research Center  

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

C. J. Walcek C. J. Walcek Atmospheric Sciences Research Center State University of New York Albany, New York Introduction intense mid latitude cyclone developed and traversed this domain, allowing one to investigate cloud cover under a wide variety of meteorological environments. Large-scale numerical models of the atmosphere approximate the heterogeneous or subgrid-scale nature of cloudiness by assuming that a fraction of each grid area is occupied by clouds. This cloud cover fraction is used to apportion cloud effects into a "grid-averaged" forcing within areas that contain a mixture of clear and cloudy regions. Most models of tropospheric dynamics assume that the fractional cloud coverage is determined by the grid- averaged relative humidity, stability, or resolvable-scale

187

Stellar model atmospheres with magnetic line blanketing. III. The role of magnetic field inclination  

E-Print Network (OSTI)

Context. See abstract in the paper. Aims. In the last paper of this series we study the effects of the magnetic field, varying its strength and orientation, on the model atmosphere structure, the energy distribution, photometric colors and the hydrogen Balmer line profiles. We compare with the previous results for an isotropic case in order to understand whether there is a clear relation between the value of the magnetic field angle and model changes, and to study how important the additional orientational information is. Also, we examine the probable explanation of the visual flux depressions of the magnetic chemically peculiar stars in the context of this work. Methods. We calculated one more grid of the model atmospheres of magnetic A and B stars for different effective temperatures (Teff=8000K, 11000K, 15000K), magnetic field strengths (B=0, 5, 10, 40 kG) and various angles of the magnetic field (Omega=0-90 degr) with respect to the atmosphere plane. We used the LLmodels code which implements a direct method for line opacity calculation, anomalous Zeeman splitting of spectral lines, and polarized radiation transfer. Results. We have not found significant changes in model atmosphere structure, photometric and spectroscopic observables or profiles of hydrogen Balmer lines as we vary the magnetic field inclination angle Omega. The strength of the magnetic field plays the main role in magnetic line blanketing. We show that the magnetic field has a clear relation to the visual flux depressions of the magnetic CP stars. Conclusions. See abstract in the paper.

S. A. Khan; D. V. Shulyak

2006-07-20T23:59:59.000Z

188

Improving the transition modelling in hidden Markov models for ECG segmentation  

E-Print Network (OSTI)

Improving the transition modelling in hidden Markov models for ECG segmentation Benoît Frénay, Gaël/ELEC/DICE - Place du Levant, 3 1348 Louvain-la-Neuve, Belgium Abstract. The segmentation of ECG signal is a useful-dependent. Experiments show that both methods improve the results on pathological ECG signals. 1 Introduction Physicians

Verleysen, Michel

189

Calculation of the far range atmospheric transport of radionuclides after the Fukushima accident with the atmospheric dispersion model MATCH of the JRODOS system  

Science Journals Connector (OSTI)

The paper presents estimates of the far-range atmospheric dispersion of radionuclides after the accident at Fukushima Daiichi Nuclear Power Plant (NPP), obtained using the long-range atmospheric dispersion model MATCH. Software tools were developed to run MATCH in the EU nuclear emergency response system JRODOS using freely available numerical weather prediction (NWP) data of the Global Forecasting System (GFS) operated by the United States National Center of Environmental Prediction (NCEP). Comparisons are made of results with JRODOS/MATCH and a standalone MATCH operated by Swedish Meteorological and Hydrological Institute (SMHI) driven by the European Center for Medium-Range Weather Forecasts (ECMWF) NWP data.

Ivan V. Kovalets; Lennart Robertson; Christer Persson; Svitlana N. Didkivska; Ievgen A. Ievdin; Dmytro Trybushnyi

2014-01-01T23:59:59.000Z

190

A DETAILED MODEL ATMOSPHERE ANALYSIS OF COOL WHITE DWARFS IN THE SLOAN DIGITAL SKY SURVEY  

SciTech Connect

We present optical spectroscopy and near-infrared photometry of 126 cool white dwarfs (WDs) in the Sloan Digital Sky Survey (SDSS). Our sample includes high proper motion targets selected using the SDSS and USNO-B astrometry and a dozen previously known ultracool WD candidates. Our optical spectroscopic observations demonstrate that a clean selection of large samples of cool WDs in the SDSS (and the SkyMapper, Pan-STARRS, and the Large Synoptic Survey Telescope data sets) is possible using a reduced proper motion diagram and a tangential velocity cut-off (depending on the proper motion accuracy) of 30 km s{sup -1}. Our near-infrared observations reveal eight new stars with significant absorption. We use the optical and near-infrared photometry to perform a detailed model atmosphere analysis. More than 80% of the stars in our sample are consistent with either pure hydrogen or pure helium atmospheres. However, the eight stars with significant infrared absorption and the majority of the previously known ultracool WD candidates are best explained with mixed hydrogen and helium atmosphere models. The age distribution of our sample is consistent with a Galactic disk age of 8 Gyr. A few ultracool WDs may be as old as 12-13 Gyr, but our models have problems matching the spectral energy distributions of these objects. There are only two halo WD candidates in our sample. However, trigonometric parallax observations are required for accurate mass and age determinations and to confirm their membership in the halo.

Kilic, Mukremin [Smithsonian Astrophysical Observatory, 60 Garden Street, Cambridge, MA 02138 (United States); Leggett, S. K. [Gemini Observatory, 670 N. A'ohoku Place, Hilo, HI 96720 (United States); Tremblay, P.-E.; Bergeron, P. [Departement de Physique, Universite de Montreal, C.P. 6128, Succursale Centre-Ville, Montreal, Quebec H3C 3J7 (Canada); Von Hippel, Ted [Physics Department, Siena College, 515 Loudon Road, Loudonville, NY 12211 (United States); Harris, Hugh C.; Munn, Jeffrey A. [U.S. Naval Observatory, Flagstaff Station, 10391 W. Naval Observatory Road, Flagstaff, AZ 86001 (United States); Williams, Kurtis A. [Department of Astronomy, 1 University Station C1400, Austin, TX 78712 (United States); Gates, Evalyn [Kavli Institute for Cosmological Physics and Department of Astronomy and Astrophysics, The University of Chicago, 5640 South Ellis Avenue, Chicago, IL 60637 (United States); Farihi, J., E-mail: mkilic@cfa.harvard.ed [Department of Physics and Astronomy, University of Leicester, Leicester LE1 7RH (United Kingdom)

2010-09-15T23:59:59.000Z

191

Comment on "Time Step Sensitivity of Nonlinear Atmospheric Models: Numerical Convergence, Truncation Error Growth, and Ensemble Design" Teixeira et al. (2007)  

E-Print Network (OSTI)

Comment on "Time Step Sensitivity of Nonlinear Atmospheric Models: Numerical Convergence, Truncation Error Growth, and Ensemble Design" Teixeira et al.

Lun-Shin Yao; Dan Hughes

2007-04-26T23:59:59.000Z

192

ENSO Bred Vectors in Coupled OceanAtmosphere General Circulation Models  

Science Journals Connector (OSTI)

The breeding method has been implemented in the NASA Seasonal-to-Interannual Prediction Project (NSIPP) coupled general circulation model (CGCM) with the ultimate goal of improving operational seasonal to interannual climate predictions through ...

S-C. Yang; E. Kalnay; M. Cai; M. Rienecker; G. Yuan; Z. Toth

2006-04-01T23:59:59.000Z

193

Non-thermal Atmospheric Plasma Treatment for Deactivation of Oral Bacteria and Improvement of Dental Composite Restoration  

Science Journals Connector (OSTI)

This paper reviews our recent research results of using non-thermal atmospheric plasmas for oral bacterial deactivation and for composite...Streptococcus mutans (S. mutans) and Lactobacillus acidophilus (L. acid...

Qing Song Yu; H. Li; A. C. Ritts; B. Yang

2012-01-01T23:59:59.000Z

194

Utilizing CLASIC observations and multiscale models to study the impact of improved Land surface representation on modeling cloud- convection  

SciTech Connect

The CLASIC experiment was conducted over the US southern great plains (SGP) in June 2007 with an objective to lead an enhanced understanding of the cumulus convection particularly as it relates to land surface conditions. This project was design to help assist with understanding the overall improvement of land atmosphere convection initiation representation of which is important for global and regional models. The study helped address one of the critical documented deficiency in the models central to the ARM objectives for cumulus convection initiation and particularly under summer time conditions. This project was guided by the scientific question building on the CLASIC theme questions: What is the effect of improved land surface representation on the ability of coupled models to simulate cumulus and convection initiation? The focus was on the US Southern Great Plains region. Since the CLASIC period was anomalously wet the strategy has been to use other periods and domains to develop the comparative assessment for the CLASIC data period, and to understand the mechanisms of the anomalous wet conditions on the tropical systems and convection over land. The data periods include the IHOP 2002 field experiment that was over roughly same domain as the CLASIC in the SGP, and some of the DOE funded Ameriflux datasets.

Niyogi, Devdutta S. [Purdue

2013-06-07T23:59:59.000Z

195

The new GFDL global atmosphere and land model AM2/LM2: Evaluation with prescribed SST simulations  

E-Print Network (OSTI)

The new GFDL global atmosphere and land model AM2/LM2: Evaluation with prescribed SST simulations climatology, and components from previous models used at GFDL. The land model, known as LM2, includes soil of the coupled model AM2/LM2 is evaluated with a series of prescribed sea-surface temperature (SST) simulations

Bretherton, Chris

196

GEOCARBSULF: A combined model for Phanerozoic atmospheric O2 and CO2  

Science Journals Connector (OSTI)

A model for the combined long-term cycles of carbon and sulfur has been constructed which combines all the factors modifying weathering and degassing of the GEOCARB III model [Berner R.A., Kothavala Z., 2001. GEOCARB III: a revised model of atmospheric CO2 over Phanerozoic time. Am. J. Sci. 301, 182204] for CO2 with rapid recycling and oxygen dependent carbon and sulfur isotope fractionation of an isotope mass balance model for O2 [Berner R.A., 2001. Modeling atmospheric O2 over Phanerozoic time. Geochim. Cosmochim. Acta 65, 685694]. New isotopic data for both carbon and sulfur are used and new feedbacks are created by combining the models. Sensitivity analysis is done by determining (1) the effect on weathering rates of using rapid recycling (rapid recycling treats carbon and sulfur weathering in terms of young rapidly weathering rocks and older more slowly weathering rocks); (2) the effect on O2 of using different initial starting conditions; (3) the effect on O2 of using different data for carbon isotope fractionation during photosynthesis and alternative values of oceanic ?13C for the past 200 million years; (4) the effect on sulfur isotope fractionation and on O2 of varying the size of O2 feedback during sedimentary pyrite formation; (5) the effect on O2 of varying the dependence of organic matter and pyrite weathering on tectonic uplift plus erosion, and the degree of exposure of coastal lands by sea level change; (6) the effect on CO2 of adding the variability of volcanic rock weathering over time [Berner, R.A., 2006. Inclusion of the weathering of volcanic rocks in the GEOCARBSULF model. Am. J. Sci. 306 (in press)]. Results show a similar trend of atmospheric CO2 over the Phanerozoic to the results of GEOCARB III, but with some differences during the early Paleozoic and, for variable volcanic rock weathering, lower CO2 values during the Mesozoic. Atmospheric oxygen shows a major broad late Paleozoic peak with a maximum value of about 30% O2 in the Permian, a secondary less-broad peak centered near the Silurian/Devonian boundary, variation between 15% and 20% O2 during the Cambrian and Ordovician, a very sharp drop from 30% to 15% O2 at the Permo-Triassic boundary, and a more-or less continuous rise in O2 from the late Triassic to the present.

Robert A. Berner

2006-01-01T23:59:59.000Z

197

Modelling the Effect of Ocean Waves on the Atmospheric and Ocean Boundary Layers  

Science Journals Connector (OSTI)

Ocean waves, in addition to generating direct forces on fixed and floating offshore wind generator structures, also have significant indirect effects via their influence on the atmospheric and oceanic boundary layers above and below the water surface. In the atmospheric boundary layer the waves act as roughness elements, influencing the turbulent flow and the vertical wind speed profile, and induce oscillatory motions in the airflow. Spray droplets from breaking wave crests enhance structure corrosion, and may lead to icing under low-temperature conditions. Below the water surface, the air-sea momentum flux and mechanical energy flux, mediated by the waves and wave-generated turbulence, affect the vertical profiles of ocean current, temperature, and salinity. Effects include modifying the structural forces and dynamics, and the movement and dispersion of marine organisms, pollutants, and air bubbles generated by breaking waves, with consequences for fouling, corrosion, and environmental impact. Measurement of relevant airflow and ocean dynamical variables is also challenging, as near the water surface it is often necessary to use instruments mounted on moving measurement platforms. Modelling such boundary-layer effects is a complex task, as a result of feedbacks between the airflow, wave field, current field, and turbulence in the atmosphere and the ocean. We present results from a coupled model study of the North Sea and Norwegian Sea area. We employ a mesoscale atmosphere model (WRF) and a spectral wave model (WAM), running simultaneously and coupled using the open-source coupler MCEL which can interpolate between different model grids and time steps. To investigate the ocean boundary layer, one-dimensional model experiments were performed for an idealized Ekman layer and for locations in the North Sea, Atlantic Ocean, and the northern Pacific, using a version of the GOTM turbulence model, modified to take wave dynamics into account. Results show how the wave field alters the ocean's aerodynamic roughness and the airsea momentum flux, depending on the relation between the surface wind speed and the propagation speed of the wave crests (the wave age). These effects will feed back into the airflow, wind speed and turbulence profile in the boundary layer. The ocean dynamics experiments showed results which compare favourably with field observations from the LOTUS3 and PROVESS experiments in the north Atlantic and North Sea, and Ocean Weather Station Papa in the Pacific Ocean.

Alastair D. Jenkins; Mostafa Bakhoday Paskyabi; Ilker Fer; Alok Gupta; Muralidhar Adakudlu

2012-01-01T23:59:59.000Z

198

Interactive Crop Management in the Community Earth System Model (CESM1): Seasonal Influences on LandAtmosphere Fluxes  

Science Journals Connector (OSTI)

The Community Earth System Model, version 1 (CESM1) is evaluated with two coupled atmosphereland simulations. The CTRL (control) simulation represents crops as unmanaged grasses, while CROP represents a crop managed simulation that includes ...

Samuel Levis; Gordon B. Bonan; Erik Kluzek; Peter E. Thornton; Andrew Jones; William J. Sacks; Christopher J. Kucharik

2012-07-01T23:59:59.000Z

199

Improving potato drought simulations: Assessing water stress factors using a coupled model  

Science Journals Connector (OSTI)

Abstract Effective water management is important for drought sensitive crops like potato (Solanum tuberosum L.). Crop simulation models are well suited for evaluating water limited responses in order to provide management and phenotypic-trait recommendations for more efficient production practice. There is considerable variation in how water stress components are implemented with regards to simulating soil, plant, and atmospheric relationships, thereby influencing the utility of model recommendations. Four water-stress factors were developed and implemented in the potato model SPUDIM in order to assess the contribution each factor provided for improving modeling accuracy. Iterative comparisons versus experimental data consisting of six irrigation treatments were used. Factors included F1, shifts in carbon allocation among shoot and root organs based on soil moisture availability, F2, coupled response of leaf water potential on leaf expansion, F3, and on stomatal conductance, and F4, increased tuber sink strength. F2 and F3 accounted for up to 88% of the improvement in root mean square error for total biomass. However, F1 and F4 were necessary to accurately simulate yield. F4 was also required to reproduce trends of increasing water-use efficiency and harvest index with declines in water availability. When the full 4-factor model was considered, simulated responses for total, leaf, stem, and tuber dry weights were within 11% of observed values. Daily comparisons for whole plant net photosynthesis and evapotranspiration indicated F3 was required to accurately simulate water use, but was too sensitive to very low leaf water potentials. The calibration coefficients used in the model remained stable over all six irrigation treatments, suggesting the full model can be utilized to evaluate water management strategies for potato.

David H. Fleisher; A. Dathe; D.J. Timlin; V.R. Reddy

2015-01-01T23:59:59.000Z

200

DOE research on atmospheric aerosols  

SciTech Connect

Atmospheric aerosols are the subject of a significant component of research within DOE`s environmental research activities, mainly under two programs within the Department`s Environmental Sciences Division, the Atmospheric Radiation Measurement (ARM) Program and the Atmospheric Chemistry Program (ACP). Research activities conducted under these programs include laboratory experiments, field measurements, and theoretical and modeling studies. The objectives and scope of these programs are briefly summarized. The ARM Program is the Department`s major research activity focusing on atmospheric processes pertinent to understanding global climate and developing the capability of predicting global climate change in response to energy related activities. The ARM approach consists mainly of testing and improving models using long-term measurements of atmospheric radiation and controlling variables at highly instrumented sites in north central Oklahoma, in the Tropical Western Pacific, and on the North Slope of Alaska. Atmospheric chemistry research within DOE addresses primarily the issue of atmospheric response to emissions from energy-generation sources. As such this program deals with the broad topic known commonly as the atmospheric source-receptor sequence. This sequence consists of all aspects of energy-related pollutants from the time they are emitted from their sources to the time they are redeposited at the Earth`s surface.

Schwartz, S.E.

1995-11-01T23:59:59.000Z

Note: This page contains sample records for the topic "improving atmospheric models" 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.


201

E-Print Network 3.0 - atmospheric emissions modeling Sample Search...  

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

well as "back radiation" downward to the surface. The atmosphere also... .e., the greenhouse effect, is included via the atmospheric ... Source: Noone, David - Program in...

202

The solar photospheric abundance of europium. Results from CO5BOLD 3-D hydrodynamical model atmospheres  

E-Print Network (OSTI)

Context. Europium is an almost pure r-process element, which may be useful as a reference in nucleocosmochronology. Aims. To determine the photospheric solar abundance using CO5BOLD 3-D hydrodynamical model atmospheres. Methods. Disc-centre and integrated-flux observed solar spectra are used. The europium abundance is derived from the equivalent width measurements. As a reference 1D model atmospheres have been used, in addition. Results. The europium photospheric solar abundance is 0.52 +- 0.02 in agreement with previous determinations. We also determine the photospheric isotopic fraction of Eu(151) to be 49 % +- 2.3 % from the intensity spectra and 50% +-2.3 from the flux spectra. This compares well to the the meteoritic isotopic fraction 47.8%. We explore the 3D corrections also for dwarfs and sub-giants in the temperature range ~5000 K to ~6500 K and solar and 1/10--solar metallicities and find them to be negligible for all the models investigated. Conclusions. Our photospheric Eu abundance is in good agreement with previous determinations based on 1D models. This is in line with our conclusion that 3D effects for this element are negligible in the case of the Sun.

A. Mucciarelli; E. Caffau; B. Freytag; H. -G. Ludwig; P. Bonifacio

2008-03-06T23:59:59.000Z

203

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

SciTech Connect

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

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

2013-02-07T23:59:59.000Z

204

Titan's past and future: 3D modeling of a pure nitrogen atmosphere and geological implications  

E-Print Network (OSTI)

Several clues indicate that Titan's atmosphere has been depleted in methane during some period of its history, possibly as recently as 0.5-1 billion years ago. It could also happen in the future. Under these conditions, the atmosphere becomes only composed of nitrogen with a range of temperature and pressure allowing liquid or solid nitrogen to condense. Here, we explore these exotic climates throughout Titan's history with a 3D Global Climate Model (GCM) including the nitrogen cycle and the radiative effect of nitrogen clouds. We show that for the last billion years, only small polar nitrogen lakes should have formed. Yet, before 1 Ga, a significant part of the atmosphere could have condensed, forming deep nitrogen polar seas, which could have flowed and flooded the equatorial regions. Alternatively, nitrogen could be frozen on the surface like on Triton, but this would require an initial surface albedo higher than 0.65 at 4 Ga. Such a state could be stable even today if nitrogen ice albedo is higher than th...

Charnay, Benjamin; Tobie, Gabriel; Sotin, Christophe; Wordsworth, Robin

2014-01-01T23:59:59.000Z

205

Carbon monoxide in the solar atmosphere I. Numerical method and two-dimensional models  

E-Print Network (OSTI)

The radiation hydrodynamic code CO5BOLD has been supplemented with the time-dependent treatment of chemical reaction networks. Advection of particle densities due to the hydrodynamic flow field is also included. The radiative transfer is treated frequency-independently, i.e. grey, so far. The upgraded code has been applied to two-dimensional simulations of carbon monoxide (CO) in the non-magnetic solar photosphere and low chromosphere. For this purpose a reaction network has been constructed, taking into account the reactions which are most important for the formation and dissociation of CO under the physical conditions of the solar atmosphere. The network has been strongly reduced to 27 reactions, involving the chemical species H, H2, C, O, CO, CH, OH, and a representative metal. The resulting CO number density is highest in the cool regions of the reversed granulation pattern at mid-photospheric heights and decreases strongly above. There, the CO abundance stays close to a value of 8.3 on the usual logarithmic abundance scale with [H]=12 but is reduced in hot shock waves which are a ubiquitous phenomenon of the model atmosphere. For comparison, the corresponding equilibrium densities have been calculated, based on the reaction network but also under assumption of instantaneous chemical equilibrium by applying the Rybicki & Hummer (RH) code by Uitenbroek (2001). Owing to the short chemical timescales, the assumption holds for a large fraction of the atmosphere, in particular the photosphere. In contrast, the CO number density deviates strongly from the corresponding equilibrium value in the vicinity of chromospheric shock waves. Simulations with altered reaction network clearly show that the formation channel via hydroxide (OH) is the most important one under the conditions of the solar atmosphere.

S. Wedemeyer-Boehm; I. Kamp; J. Bruls; B. Freytag

2005-03-23T23:59:59.000Z

206

Oxy-nitroso shielding burst model of cold atmospheric plasma therapeutics  

Science Journals Connector (OSTI)

Abstract It is postulated that cold atmospheric plasma (CAP) can trigger a therapeutic shielding response in tissue by creating a time- and space-localized, burst-like form of oxy-nitrosative stress on near-surface exposed cells through the flux of plasma-generated reactive oxygen and nitrogen species (RONS). RONS-exposed surface layers of cells communicate to the deeper levels of tissue via a form of the bystander effect, similar to responses to other forms of cell stress. In this proposed model of CAP therapeutics, the plasma stimulates a cellular survival mechanism through which aerobic organisms shield themselves from infection and other challenges.

David B Graves

2014-01-01T23:59:59.000Z

207

Modeling and Data Needs of Atmospheric Pressure Gas Plasma and Biomaterial Interaction  

SciTech Connect

Non-thermal atmospheric pressure plasmas have received considerable attention recently. One promising application of non-thermal plasma devices appears to be biomaterial and biomedical treatment. Various biological and medical effects of non-thermal plasmas have been observed by a variety of investigators, including bacteria sterilization, cell apoptosis, and blood coagulation, among others. The mechanisms of the plasma-biomaterial interaction are however only poorly understood. A central scientific challenge is therefore how to answer the question: 'What plasma-generated agents are responsible for the observed biological effects?' Our modeling efforts are motivated by this question. In this paper, we review our modeling results of the plasma needle discharge. Then, we address data needs for further modeling and understanding of plasma-biomaterial interaction.

Sakiyama, Yukinori; Graves, David B. [Department of Chemical Engineering, University of California at Berkeley, Berkeley, CA 94720 (United States)

2009-05-02T23:59:59.000Z

208

Modeling and Data Needs of Atmospheric Pressure Gas Plasma and Biomaterial Interaction  

Science Journals Connector (OSTI)

Non?thermal atmospheric pressure plasmas have received considerable attention recently. One promising application of non?thermal plasma devices appears to be biomaterial and biomedical treatment. Various biological and medical effects of non?thermal plasmas have been observed by a variety of investigators including bacteria sterilization cell apoptosis and blood coagulation among others. The mechanisms of the plasma?biomaterial interaction are however only poorly understood. A central scientific challenge is therefore how to answer the question: What plasma?generated agents are responsible for the observed biological effects? Our modeling efforts are motivated by this question. In this paper we review our modeling results of the plasma needle discharge. Then we address data needs for further modeling and understanding of plasma?biomaterial interaction

Yukinori Sakiyama; David B. Graves

2009-01-01T23:59:59.000Z

209

Fabrication of ZnO/Cu2O heterojunctions in atmospheric conditions: improved interface quality and solar cell performance  

E-Print Network (OSTI)

Zn_1-xMg_xO/Cu_2O heterojunctions were successfully fabricated in open-air at low temperatures via atmospheric atomic layer deposition of Zn_1-xMg_xO on thermally oxidized cuprous oxide. Solar cells employing these heterojunctions demonstrated a...

Ievskaya, Y.; Hoye, R. L. Z.; Sadhanala, A.; Musselman, K.; MacManus-Driscoll, J. L.

2014-01-01T23:59:59.000Z

210

Dark Stars: Improved Models and First Pulsation Results  

E-Print Network (OSTI)

(Abridged) We use the stellar evolution code MESA to study dark stars. Dark stars (DSs), which are powered by dark matter (DM) self-annihilation rather than by nuclear fusion, may be the first stars to form in the Universe. We compute stellar models for accreting DSs with masses up to 10^6 M_sun. While previous calculations were limited to polytropic interiors, our current calculations use MESA, a modern stellar evolution code to solve the equations of stellar structure. The heating due to DM annihilation is self-consistently included, assuming extended adiabatic contraction of DM within the minihalos in which DSs form. We find remarkably good overall agreement with the basic results of previous models. There are some differences, however, in the details, with positive implications for observability of DSs. We found that, in the mass range of 10^4 - 10^5 M_sun, using MESA, our DSs are hotter by a factor of 1.5 than those in Freese et al.(2010), are smaller in radius by a factor of 0.6, denser by a factor of 3-4, and more luminous by a factor of 2. The higher luminosities we find improve the prospect of observing DSs in upcoming observations using the James Webb Space Telescope. Our improved models also confirm previous results, according to which DSs are very well approximated by (n=3)-polytropes. Earlier findings on the properties of supermassive DSs have thus turned out to be robust. We also perform a first study of DS pulsations. Our DS models have pulsation modes with timescales which range from less than a day to more than two years in their rest frames, at a redshift of about 15, depending on DM particle mass and overtone number. Such pulsations may someday be used to identify bright, cool objects uniquely as DSs; if properly calibrated, they might, in principle, also supply novel standard candles for cosmological studies.

Tanja Rindler-Daller; Michael H. Montgomery; Katherine Freese; Donald E. Winget; Bill Paxton

2014-08-09T23:59:59.000Z

211

Development of an Atmospheric Climate Model with Self-Adapting Grid and Physics  

SciTech Connect

This project was targeting the development of a computational approach that would allow resolving cloud processes on small-scales within the framework of the most recent version of the NASA/NCAR Finite-Volume Community Atmospheric Model (FVCAM). The FVCAM is based on the multidimensional Flux-Form Semi-Lagrangian (FFSL) dynamical core and uses a ?vertically Lagrangian? finite-volume (FV) representation of the model equations with a mass-conserving re-mapping algorithm. The Lagrangian coordinate requires a remapping of the Lagrangian volume back to Eulerian coordinates to restore the original resolution and keep the mesh from developing distortions such as layers with overlapping interfaces. The main objectives of the project were, first, to develop the 3D library which allows refinement and coarsening of the model domain in spherical coordinates, and second, to develop a non-hydrostatic code for calculation of the model variables within the refined areas that could be seamlessly incorporated with the hydrostatic finite volume dynamical core when higher resolution is wanted. We also updated the aerosol simulation model in CAM in order to ready the model for the treatment of aerosol/cloud interactions.

Penner, Joyce E. [University of Michigan] University of Michigan

2013-08-10T23:59:59.000Z

212

A New Ensemble of Perturbed-Input-Parameter Simulations by the Community Atmosphere Model  

SciTech Connect

Uncertainty quantification (UQ) is a fundamental challenge in the numerical simulation of Earth's weather and climate, and other complex systems. It entails much more than attaching defensible error bars to predictions: in particular it includes assessing low-probability but high-consequence events. To achieve these goals with models containing a large number of uncertain input parameters, structural uncertainties, etc., raw computational power is needed. An automated, self-adapting search of the possible model configurations is also useful. Our UQ initiative at the Lawrence Livermore National Laboratory has produced the most extensive set to date of simulations from the US Community Atmosphere Model. We are examining output from about 3,000 twelve-year climate simulations generated with a specialized UQ software framework, and assessing the model's accuracy as a function of 21 to 28 uncertain input parameter values. Most of the input parameters we vary are related to the boundary layer, clouds, and other sub-grid scale processes. Our simulations prescribe surface boundary conditions (sea surface temperatures and sea ice amounts) to match recent observations. Fully searching this 21+ dimensional space is impossible, but sensitivity and ranking algorithms can identify input parameters having relatively little effect on a variety of output fields, either individually or in nonlinear combination. Bayesian statistical constraints, employing a variety of climate observations as metrics, also seem promising. Observational constraints will be important in the next step of our project, which will compute sea surface temperatures and sea ice interactively, and will study climate change due to increasing atmospheric carbon dioxide.

Covey, C; Brandon, S; Bremer, P T; Domyancis, D; Garaizar, X; Johannesson, G; Klein, R; Klein, S A; Lucas, D D; Tannahill, J; Zhang, Y

2011-10-27T23:59:59.000Z

213

3D Atmospheric Radiative Transfer for Cloud System-Resolving Models: Forward Modelling and Observations  

SciTech Connect

Utilization of cloud-resolving models and multi-dimensional radiative transfer models to investigate the importance of 3D radiation effects on the numerical simulation of cloud fields and their properties.

Howard Barker; Jason Cole

2012-05-17T23:59:59.000Z

214

Acidbase chemical reaction model for nucleation rates in the polluted atmospheric boundary layer  

E-Print Network (OSTI)

Atmospheric Sciences Division, Brookhaven National Laboratory, Upton, NY 11973; f Sustainable Energy Systems Group, Environmental Energy Technologies Division, E. O. Lawrence Berkeley National Laboratory, Berkeley agreement with measurements from Mexico City and Atlanta. amines | atmospheric aerosol | climate forcing

215

Stable spatial Langmuir solitons as a model of long-lived atmospheric plasma structures  

E-Print Network (OSTI)

I study stable spatial Langmuir solitons in plasma based on nonlinear radial oscillations of charged particles. I discuss two situations when a Langmuir soliton can be stable. In the former case the stability of solitons against the collapse is due to electron-electron interactions which result in the nonlocal terms in the nonlinear Schr\\"{o}dinger equation. In the latter situation I derive the new cubic-quintic nonlinear Schr\\"{o}dinger equation with accounts for the interaction of induced dipole moments of diatomic ions with a rapidly oscillating electric field and show that the collapse of Langmuir waves can be also arrested. In both cases I find the numerical solutions of the nonlinear Schr\\"{o}dinger equation and analyze their stability using the Vakhitov-Kolokolov criterion. I discuss the application of my results for the description of long-lived atmospheric plasma structures. I show that, using my model, one can explain the existence of atmospheric plasmoids in the upper ionosphere. It is also demonst...

Dvornikov, Maxim

2014-01-01T23:59:59.000Z

216

COUNTERCURRENT FLOW LIMITATION EXPERIMENTS AND MODELING FOR IMPROVED REACTOR SAFETY  

SciTech Connect

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

Vierow, Karen

2008-09-26T23:59:59.000Z

217

IMPROVEMENT OF THE WIND FARM MODEL FLAP FOR OFFSHORE APPLICATIONS Bernhard Lange(1), Hans-Peter Waldl(1)(2), Rebecca Barthelmie(3), Algert Gil Guerrero(1)(4), Detlev Heinemann(1)  

E-Print Network (OSTI)

IMPROVEMENT OF THE WIND FARM MODEL FLAP FOR OFFSHORE APPLICATIONS Bernhard Lange(1), Hans the description of wake development in offshore conditions, especially the low ambient turbulence and the effect of atmospheric stability. Model results have been compared with measurements from the Danish offshore wind farm

Heinemann, Detlev

218

ATMOSPHERE AND SPECTRAL MODELS OF THE KEPLER-FIELD PLANETS HAT-P-7b AND TrES-2  

SciTech Connect

We develop atmosphere models of two of the three Kepler-field planets that were known prior to the start of the Kepler mission (HAT-P-7b and TrES-2). We find that published Kepler and Spitzer data for HAT-P-7b appear to require an extremely hot upper atmosphere on the dayside, with a strong thermal inversion and little day-night redistribution. The Spitzer data for TrES-2 suggest a mild thermal inversion with moderate day-night redistribution. We examine the effect of nonequilibrium chemistry on TrES-2 model atmospheres and find that methane levels must be adjusted by extreme amounts in order to cause even mild changes in atmospheric structure and emergent spectra. Our best-fit models to the Spitzer data for TrES-2 lead us to predict a low secondary eclipse planet-star flux ratio ({approx}<2 x 10{sup -5}) in the Kepler bandpass, which is consistent with what very recent observations have found. Finally, we consider how the Kepler-band optical flux from a hot exoplanet depends on the strength of a possible extra optical absorber in the upper atmosphere. We find that the optical flux is not monotonic in optical opacity, and the non-monotonicity is greater for brighter, hotter stars.

Spiegel, David S.; Burrows, Adam, E-mail: dsp@astro.princeton.ed, E-mail: burrows@astro.princeton.ed [Department of Astrophysical Sciences, Peyton Hall, Princeton University, Princeton, NJ 08544 (United States)

2010-10-10T23:59:59.000Z

219

Fine resolution atmospheric sulfate model driven by operational meteorological data: Comparison with observations  

SciTech Connect

The hypothesis that anthropogenic sulfur aerosol influences clear-sky and cloud albedo and can thus influence climate has been advanced by several investigators; current global-average climate forcing is estimated to be of comparable magnitude, but opposite sign, to longwave forcing by anthropogenic greenhouse gases. The high space and time variability of sulfate concentrations and column aerosol burdens have been established by observational data; however, geographic and time coverage provided by data from surface monitoring networks is very limited. Consistent regional and global estimates of sulfate aerosol loading, and the contributions to this loading from different sources can be obtained only by modeling studies. Here we describe a sub-hemispheric to global-scale Eulerian transport and transformation model for atmospheric sulfate and its precursors, driven by operational meteorological data, and report results of calculations for October, 1986 for the North Atlantic and adjacent continental regions. The model, which is based on the Global Chemistry Model uses meteorological data from the 6-hour forecast model of the European Center for Medium-Range Weather Forecast to calculate transport and transformation of sulfur emissions. Time- and location-dependent dry deposition velocities were estimated using the methodology of Wesely and colleagues. Chemical reactions includes gaseous oxidation of SO{sub 2} and DMS by OH, and aqueous oxidation of SO{sub 2} by H{sub 2}O{sub 2} and O{sub 3}. Anthropogenic emissions were from the NAPAP and EMEP 1985 inventories and biogenic emissions based on Bates et al. Calculated sulfate concentrations and column burdens exhibit high variability on spatial scale of hundreds of km and temporal scale of days. Calculated daily average sulfate concentrations closely reproduce observed concentrations at locations widespread over the model domain.

Benkovitz, C.M.; Schwartz, S.E. [Brookhaven National Lab., Upton, NY (United States); Berkowitz, C.M.; Easter, R.C. [Battelle Pacific Northwest Lab., Richland, WA (United States)

1993-09-01T23:59:59.000Z

220

Prioritizing Data for Improving the Multi-decadal Predictive Capability of Atmospheric Models  

Science Journals Connector (OSTI)

The prioritization accorded to observation types currently being considered for a space-based climate observing system is extended from a previous study. Hind-cast averages and trends from 1970 through 2005 of longitude-latitude maps of 200-hPa ...

Stephen S. Leroy; Gianluca Redaelli; Barbara Grassi

Note: This page contains sample records for the topic "improving atmospheric models" 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

Simple model to estimate the contribution of atmospheric CO2 to the Earths greenhouse effect  

Science Journals Connector (OSTI)

We show how the CO2 contribution to the Earths greenhouse effect can be estimated from relatively simple physical considerations and readily available spectroscopic data. In particular we present a calculation of the climate sensitivity (that is the increase in temperature caused by a doubling of the concentration of CO2) in the absence of feedbacks. Our treatment highlights the important role played by the frequency dependence of the CO2absorptionspectrum. For pedagogical purposes we provide two simple models to visualize different ways in which the atmosphere might return infrared radiation back to the Earth. The more physically realistic model based on the Schwarzschild radiative transfer equations uses as input an approximate form of the atmospheres temperature profile and thus includes implicitly the effect of heat transfer mechanisms other than radiation.

Derrek J. Wilson; Julio Gea-Banacloche

2012-01-01T23:59:59.000Z

222

Comparison of Atmospheric Water Vapor in Observational and Model Data Sets  

SciTech Connect

The global water vapor distribution for five observational based data sets and three GCM integrations are compared. The variables considered are the mean and standard deviation values of the precipitable water for the entire atmospheric column and the 500 to 300 hPa layer for January and July. The observationally based sets are the radiosonde data of Ross and Elliott, the ERA and NCEP reanalyses, and the NVAP blend of sonde and satellite data. The three GCM simulations all use the NCAR CCM3 as the atmospheric model. They include: a AMIP type simulation using observed SSTs for the period 1979 to 1993, the NCAR CSM 300 year coupled ocean--atmosphere integration, and a CSM integration with a 1% CO2 increase per year. The observational data exhibit some serious inconsistencies. There are geographical patterns of differences related to interannual variations and national instrument biases. It is clear that the proper characterization of water vapor is somewhat uncertain. Some conclusions about these data appear to be robust even given the discrepancies. The ERA data are too dry especially in the upper levels. The observational data evince much better agreement in the data rich Northern Hemisphere compared to the Southern. Distinct biases are quite pronounced over the Southern Ocean. The mean values and particularly the standard deviations of the three reanalyses are very dependent upon the GCM used as the assimilation vehicle for the analyses. This is made clear by the much enhanced tropical variability in the NCEP/DOE/ AMIP reanalyses compared the initial NCEP/NCAR Reanalysis. The NCAR CCM3 shows consistent evidence of a dry bias. The 1% CO2 experiment shows a very similar pattern of disagreement with the sonde data as the other integrations, once account is taken of the warming trend. No new modes of difference are evident in the 1% CO2 experiment. All the CCM3 runs indicated too much Tropical variability especially in the western Tropical Pacific and Southeast Asia. A EOF analysis of the interannual variations of the zonally averaged precipitable water and the 500 to 300 hPa layer reveals fundamental differences in the structure of the variations. The impact of ENSO and variations of the ITCZ have only a low level of correspondence between the observed data, much less the simulations. It is apparent that an adequate characterization of the climatology of the global water vapor distribution is not yet at hand.

Boyle, J.S.

2000-03-01T23:59:59.000Z

223

Improved  

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

Improved Improved cache performance in Monte Carlo transport calculations using energy banding A. Siegel a , K. Smith b , K. Felker c,∗ , P . Romano b , B. Forget b , P . Beckman c a Argonne National Laboratory, Theory and Computing Sciences and Nuclear Engineering Division b Massachusetts Institute of Technology, Department of Nuclear Science and Engineering c Argonne National Laboratory, Theory and Computing Sciences Abstract We present an energy banding algorithm for Monte Carlo (MC) neutral parti- cle transport simulations which depend on large cross section lookup tables. In MC codes, read-only cross section data tables are accessed frequently, ex- hibit poor locality, and are typically much too large to fit in fast memory. Thus, performance is often limited by long latencies to RAM, or by off-node communication latencies when the data footprint is very large and must be decomposed on

224

Atmospheric Pollution Research 1 (2010) 220228 Atmospheric Pollution Research  

E-Print Network (OSTI)

Atmospheric Pollution Research 1 (2010) 220228 Atmospheric Pollution Research www in modeling of the associated multiphase processes. Iron redox species are important pollutants. The oxidative capacity of the atmospheric cloud water decreases when dissolution is included

Boyer, Edmond

225

Low-frequency variability and heat transport in a low-order nonlinear coupled ocean-atmosphere model  

E-Print Network (OSTI)

We formulate and study a low-order nonlinear coupled ocean-atmosphere model with an emphasis on the impact of radiative and heat fluxes and of the frictional coupling between the two components. This model version extends a previous 24-variable version by adding a dynamical equation for the passive advection of temperature in the ocean, together with an energy balance model. The bifurcation analysis and the numerical integration of the model reveal the presence of low-frequency variability (LFV) concentrated on and near a long-periodic, attracting orbit. This orbit combines atmospheric and oceanic modes, and it arises for large values of the meridional gradient of radiative input and of frictional coupling. Chaotic behavior develops around this orbit as it loses its stability; this behavior is still dominated by the LFV on decadal and multi-decadal time scales that is typical of oceanic processes. Atmospheric diagnostics also reveals the presence of predominant low- and high-pressure zones, as well as of a subtropical jet; these features recall realistic climatological properties of the oceanic atmosphere. Finally, a predictability analysis is performed. Once the decadal-scale periodic orbits develop, the coupled system's short-term instabilities --- as measured by its Lyapunov exponents --- are drastically reduced, indicating the ocean's stabilizing role on the atmospheric dynamics. On decadal time scales, the recurrence of the solution in a certain region of the invariant subspace associated with slow modes displays some extended predictability, as reflected by the oscillatory behavior of the error for the atmospheric variables at long lead times.

Stphane Vannitsem; Jonathan Demaeyer; Lesley De Cruz; Michael Ghil

2014-12-01T23:59:59.000Z

226

POPDOSE-SR: A Routine Release Atmospheric Population Dose Model Used at SRS  

SciTech Connect

POPDOSE-SR is used to calculate dose to the surrounding Savannah River Site (SRS) population following routine releases of atmospheric radioactivity.

Simpkins, A.A.

2001-04-04T23:59:59.000Z

227

Atmospheric Physics and Earth Observations  

Science Journals Connector (OSTI)

...has been used by atmospheric modelers as a vertical...Ackerman, in Atmospheric Physics from Spacelab...shut-tle allows recovery of the film, we...dry nitrogen at atmospheric pressure. To avoid water condensation on the optical...

M. HERS

1984-07-13T23:59:59.000Z

228

Forecasting a large number of tropical cyclone intensities around Japan using a high-resolution atmosphere-ocean coupled model  

Science Journals Connector (OSTI)

This work quantifies the benefits of using a high-resolution atmosphere-ocean coupled model in the tropical cyclone (TC) intensity forecasts in the vicinity of Japan. To do so, a large number of high-resolution calculations were performed by ...

Kosuke Ito; Tohru Kuroda; Kazuo Saito; Akiyoshi Wada

229

A model study of the impact of magnetic field structure on atmospheric composition during solar proton events  

E-Print Network (OSTI)

A model study of the impact of magnetic field structure on atmospheric composition during solar is possible into regions that are at the moment effectively shielded by the Earth's magnetic field. A two (process, timescale, magnetostratigraphy); 1650 Global Change: Solar variability; 2716 Magnetospheric

Steinhoff, Heinz-Jürgen

230

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

SciTech Connect

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

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

2013-01-01T23:59:59.000Z

231

Atmospheric Chemistry  

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

competencies Atmospheric Chemistry Atmospheric Chemistry is the study of the composition of the atmosphere, the sources and fates of gases and particles in air, and changes induced...

232

Regional Modeling of the Atmospheric Fate and Transport of Benzene and Diesel Particles  

Science Journals Connector (OSTI)

It is oxidized in the atmosphere slowly by hydroxyl (OH) radicals; its atmospheric lifetime is on the order of 1 week. ... The surrogates used in this study include agriculture, airports, housing, major highways, ports, population, railroads, water, and land area. ... PM2.5 emissions from the 1996 EPA National Emission Trends (NET) were used to generate diesel particle emissions. ...

Christian Seigneur; Betty Pun; Kristen Lohman; Shiang-Yuh Wu

2003-10-17T23:59:59.000Z

233

A new model of cosmogenic production of radiocarbon 14 C in the atmosphere  

E-Print Network (OSTI)

of primary cosmic ray particles ranging from 0.1 to 1000 GeV/nucleon. We have calculated the global in the atmosphere by the primary cosmic rays of the given type with the fixed energy and unit intensity outside the atmosphere), which can be convoluted with any given energy spectrum of the primary cosmic rays (e.g., Webber

Usoskin, Ilya G.

234

A Sensitivity Study of Radiative Fluxes at the Top of Atmosphere to Cloud-Microphysics and Aerosol Parameters in the Community Atmosphere Model CAM5  

SciTech Connect

In this study, we investigated the sensitivity of net radiative fluxes (FNET) at the top of atmosphere (TOA) to 16 selected uncertain parameters mainly related to the cloud microphysics and aerosol schemes in the Community Atmosphere Model version 5 (CAM5). We adopted a quasi-Monte Carlo (QMC) sampling approach to effectively explore the high dimensional parameter space. The output response variables (e.g., FNET) were simulated using CAM5 for each parameter set, and then evaluated using generalized linear model analysis. In response to the perturbations of these 16 parameters, the CAM5-simulated global annual mean FNET ranges from -9.8 to 3.5 W m-2 compared to the CAM5-simulated FNET of 1.9 W m-2 with the default parameter values. Variance-based sensitivity analysis was conducted to show the relative contributions of individual parameter perturbation to the global FNET variance. The results indicate that the changes in the global mean FNET are dominated by those of cloud forcing (CF) within the parameter ranges being investigated. The size threshold parameter related to auto-conversion of cloud ice to snow is confirmed as one of the most influential parameters for FNET in the CAM5 simulation. The strong heterogeneous geographic distribution of FNET variation shows parameters have a clear localized effect over regions where they are acting. However, some parameters also have non-local impacts on FNET variance. Although external factors, such as perturbations of anthropogenic and natural emissions, largely affect FNET variations at the regional scale, their impact is weaker than that of model internal parameters in terms of simulating global mean FNET in this study. The interactions among the 16 selected parameters contribute a relatively small portion of the total FNET variations over most regions of the globe. This study helps us better understand the CAM5 model behavior associated with parameter uncertainties, which will aid the next step of reducing model uncertainty via calibration of uncertain model parameters with the largest sensitivity.

Zhao, Chun; Liu, Xiaohong; Qian, Yun; Yoon, Jin-Ho; Hou, Zhangshuan; Lin, Guang; McFarlane, Sally A.; Wang, Hailong; Yang, Ben; Ma, Po-Lun; Yan, Huiping; Bao, Jie

2013-11-08T23:59:59.000Z

235

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

E-Print Network (OSTI)

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

236

Atmospheric Rivers Induced Heavy Precipitation and Flooding in the Western U.S. Simulated by the WRF Regional Climate Model  

SciTech Connect

Twenty years of regional climate simulated by the Weather Research and Forecasting model for North America has been analyzed to study the influence of the atmospheric rivers and the role of the land surface on heavy precipitation and flooding in the western U.S. Compared to observations, the simulation realistically captured the 95th percentile extreme precipitation, mean precipitation intensity, as well as the mean precipitation and temperature anomalies of all the atmospheric river events between 1980-1999. Contrasting the 1986 President Day and 1997 New Year Day atmospheric river events, differences in atmospheric stability are found to have an influence on the spatial distribution of precipitation in the Coastal Range of northern California. Although both cases yield similar amounts of heavy precipitation, the 1997 case was found to produce more runoff compared to the 1986 case. Antecedent soil moisture, the ratio of snowfall to total precipitation (which depends on temperature), and existing snowpack all seem to play a role, leading to a higher runoff to precipitation ratio simulated for the 1997 case. This study underscores the importance of characterizing or simulating atmospheric rivers and the land surface conditions for predicting floods, and for assessing the potential impacts of climate change on heavy precipitation and flooding in the western U.S.

Leung, Lai R.; Qian, Yun

2009-02-12T23:59:59.000Z

237

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

SciTech Connect

This project examined the potential large-scale influence of marine aerosol cycling on atmospheric chemistry, physics and radiative transfer. Measurements indicate that the size-dependent generation of marine aerosols by wind waves at the ocean surface and the subsequent production and cycling of halogen-radicals are important but poorly constrained processes that influence climate regionally and globally. A reliable capacity to examine the role of marine aerosol in the global-scale atmospheric system requires that the important size-resolved chemical processes be treated explicitly. But the treatment of multiphase chemistry across the breadth of chemical scenarios encountered throughout the atmosphere is sensitive to the initial conditions and the precision of the solution method. This study examined this sensitivity, constrained it using high-resolution laboratory and field measurements, and deployed it in a coupled chemical-microphysical 3-D atmosphere model. First, laboratory measurements of fresh, unreacted marine aerosol were used to formulate a sea-state based marine aerosol source parameterization that captured the initial organic, inorganic, and physical conditions of the aerosol population. Second, a multiphase chemical mechanism, solved using the Max Planck Institute for Chemistry??s MECCA (Module Efficiently Calculating the Chemistry of the Atmosphere) system, was benchmarked across a broad set of observed chemical and physical conditions in the marine atmosphere. Using these results, the mechanism was systematically reduced to maximize computational speed. Finally, the mechanism was coupled to the 3-mode modal aerosol version of the NCAR Community Atmosphere Model (CAM v3.6.33). Decadal-scale simulations with CAM v.3.6.33, were run both with and without reactive-halogen chemistry and with and without explicit treatment of particulate organic carbon in the marine aerosol source function. Simulated results were interpreted (1) to evaluate influences of marine aerosol production on the microphysical properties of aerosol populations and clouds over the ocean and the corresponding direct and indirect effects on radiative transfer; (2) atmospheric burdens of reactive halogen species and their impacts on O3, NOx, OH, DMS, and particulate non-sea-salt SO42-; and (3) the global production and influences of marine-derived particulate organic carbon. The model reproduced major characteristics of the marine aerosol system and demonstrated the potential sensitivity of global, decadal-scale climate metrics to multiphase marine-derived components of Earth??s troposphere. Due to the combined computational burden of the coupled system, the currently available computational resources were the limiting factor preventing the adequate statistical analysis of the overall impact that multiphase chemistry might have on climate-scale radiative transfer and climate.

Keene, William C. [University of Virginia] [University of Virginia; Long, Michael S. [University of Virginia] [University of Virginia

2013-05-20T23:59:59.000Z

238

Data Collection for Improved Cold Temperature Thermal Modeling...  

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

Vehicle Speed Dynamometer CAN measured Drive trace measurement Engine RPM CAN spark frequency Model input Brake Torque CAN Flywheel torque, model input Toil Dipstick...

239

Improved Space Charge Modeling for Simulation and Design of Photoinjectors  

SciTech Connect

Photoinjectors in advanced high-energy accelerators reduce beam energy spreads and enhance undulator photon fluxes. Photoinjector design is difficult because of the substantial differences in time and spatial scales. This Phase I program explored an innovative technique, the local Taylor polynomial (LTP) formulation, for improving finite difference analysis of photoinjectors. This included improved weighting techniques, systematic formula for high order interpolation and electric field computation, and improved handling of space charge. The Phase I program demonstrated that the approach was powerful, accurate, and efficient. It handles space charge gradients better than currently available technology.

Robert H. Jackson, Thuc Bui, John Verboncoeur

2010-04-19T23:59:59.000Z

240

Improving Face Recognition Performance Using a Hierarchical Bayesian Model  

E-Print Network (OSTI)

which can result in an improved recognition performance over already existing baseline approaches. We use Kernelized Fisher Discriminant Analysis (KFLD) as our baseline as it is superior to PCA in a way that it produces well separated classes even under...

Shikaripur Nadig, Ashwini

2010-04-27T23:59:59.000Z

Note: This page contains sample records for the topic "improving atmospheric models" 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

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

Energy.gov (U.S. Department of Energy (DOE))

Improved Geothermometry Through Multivariate Reaction Path Modeling and Evaluation of Geomicrobiological Influences on Geochemical Temperature Indicators presentation at the April 2013 peer review meeting held in Denver, Colorado.

242

Improvement of Electrocatalyst Performance in Hydrogen Fuel Cells by Multiscale Modelling.  

E-Print Network (OSTI)

??The work in this thesis addresses the improvement of electrocatalyst performance inhydrogen PEM fuel cells. An agglomerate model for a catalyst layer was coupled witha (more)

Marthosa, Sutida

2012-01-01T23:59:59.000Z

243

Evaluation of Atmospheric Transport Models for Use in Phase II of the Historical Public Exposures Studies at the Rocky Flats Plant  

Science Journals Connector (OSTI)

Five atmospheric transport models were evaluated for use in Phase II of the Historical Public Exposures Studies at the Rocky Flats Plant. Models included a simple straight-line ... hexafluoride tracer measurement...

Arthur S. Rood; George G. Killough; John E. Till

1999-08-01T23:59:59.000Z

244

Comparison between Observed and Model Simulated Atmospheric Circulation Patterns Associated with Extreme Temperature Days over North America using CMIP5 Historical Simulations  

Science Journals Connector (OSTI)

Circulation patterns associated with extreme temperature days over North America as simulated by a suite of climate models are compared with those obtained from observations. Seventeen coupled atmosphere-ocean general circulation models ...

Paul C. Loikith; Anthony J. Broccoli

245

Application of Improved Grey Model in Long-term Load Forecasting of Power Engineering  

Science Journals Connector (OSTI)

Grey model is usually been used for long-term load forecasting in power engineering, but it has significant limitations. If the moving average method and Markov model are connected with grey model, the accuracy of this improved grey model used for long-term load forecasting in power engineering can be effectively increased. In this paper, ordinary grey model and improved grey model are all chosen and used for long-term power load forecasting in power engineering, and the power load data of Qingdao in the past decade is selected for the analysis. The result of the analysis shows that the accuracy of improved grey model is significant higher than ordinary model, so the improved grey model can be used for long-term load forecasting in power engineering.

Junjie Kang; Huijuan Zhao

2012-01-01T23:59:59.000Z

246

Surface modification of biphasic calcium phosphate scaffolds by non-thermal atmospheric pressure nitrogen and air plasma treatment for improving osteoblast attachment and proliferation  

Science Journals Connector (OSTI)

Abstract Surface modifications induced by non-thermal plasma have been used extensively in biomedical applications. The attachment and proliferation of osteoblast cells are important in bone tissue engineering using scaffolds. Hence the effect of non-thermal plasma on hydroxyapatite/?-tri-calcium phosphate (HA/?-TCP) scaffolds in terms of improving osteoblast attachment and proliferation was investigated. Experimental groups were treated with non-thermal plasma for 10min and 20min and a control group was not treated with non-thermal plasma. For surface chemistry analysis, X-ray photoelectron spectroscopy (XPS) analysis was carried out. The hydrophilicity was determined from contact angle measurement on the surface. Atomic force microscopy analysis (AFM) was used to test the change in surface roughness and cell attachment and proliferation were evaluated using MC3T3-E1 osteoblast cells. XPS spectra revealed a decreased amount of carbon on the surface of the plasma-treated sample. The contact angle was also decreased following plasma treatment, indicating improved hydrophilicity of plasma-treated surfaces compared to the untreated disc. A significant increase in MC3T3E-1 cell attachment and proliferation was noted on plasma-treated samples as compared to untreated specimens. The results suggest that non-thermal atmospheric pressure nitrogen and air plasma treatments provide beneficial surface characteristics on HA/?-TCP scaffolds.

Yu-Ri Choi; Jae-Sung Kwon; Doo-Hoon Song; Eun Ha Choi; Yong-Keun Lee; Kyoung-Nam Kim; Kwang-Mahn Kim

2013-01-01T23:59:59.000Z

247

Inactivation of Microorganisms in Model Biofilms by an Atmospheric Pressure Pulsed Non-thermal Plasma  

Science Journals Connector (OSTI)

Non-thermal plasma jet formed by self-running pulsed-periodical ... current spark generator (PPSG) was used for atmospheric pressure inactivation of microorganisms including biofilms. A ... the PPSG is a formatio...

Yuri Akishev; N. Trushkin; M. Grushin

2012-01-01T23:59:59.000Z

248

Environmental Research 95 (2004) 247265 Modeling the atmospheric transport and deposition of mercury  

E-Print Network (OSTI)

, atmospheric deposition is now believed to be a more significant loading pathway for these lakes. Mass balance calculations for Lake Michigan (Mason and Sullivan, 1997) and Lake Superior (Dolan et al., 1993) indicate

249

Modeling Studies of Atmospheric Pressure Microplasmas: Plasma Dynamics, Surface Interaction and Applications.  

E-Print Network (OSTI)

??Technologies based on atmospheric-pressure microplasmas (APMs) have been widely developed due to the unique nature microplasmas being non-equilibrium and its ability to operate stably at (more)

Wang, Jun-Chieh

2014-01-01T23:59:59.000Z

250

Modeling the Interaction between the Atmospheric and Oceanic Boundary Layers, Including a Surface Wave Layer  

Science Journals Connector (OSTI)

The interaction between the atmospheric and oceanic boundary layers is simulated by solving a closed system of equations including equations of motion, turbulent kinetic energy (TKE), turbulent exchange coefficient (TEC), expressions for air and ...

Le Ngoc Ly

1986-08-01T23:59:59.000Z

251

A Regional OceanAtmosphere Model for Eastern Pacific Climate: Toward Reducing Tropical Biases*  

E-Print Network (OSTI)

.5°) of the ROAM enables it to capture mesoscale features, such as tropical instability waves, Central American gap these asymmetric features despite a solar radia- tion forcing at the top of the atmosphere that is zonally uniform

Wang, Yuqing

252

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

E-Print Network (OSTI)

Vapor intrusion is the migration of volatile organic compounds (VOCs) from a subsurface source into the indoor air of an overlying building. Vapor intrusion models, including the Johnson and Ettinger (J&E) model, can be ...

Friscia, Jessica M. (Jessica Marie)

2014-01-01T23:59:59.000Z

253

Development of an equipment management model to improve effectiveness of processes  

SciTech Connect

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

Chang, H. S.; Ju, T. Y.; Song, T. Y. [Korea Hydro and Nuclear Power Co., Ltd., 25-1 Jang-dong, Yuseong-gu, Daejeon, 305-343 (Korea, Republic of)

2012-07-01T23:59:59.000Z

254

A model for improving ocean wind forecasts using satellite  

E-Print Network (OSTI)

Using the dynamical model from previous talk we now want to assimilate the satellite measurements Using the dynamical model from previous talk we now want to assimilate the satellite measurements now want to assimilate the satellite measurements into this model. We will discuss the measurement

Malmberg, Anders

255

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

SciTech Connect

Optimization of an advanced coal-fired integrated gasification combined cycle system requires an accurate numerical prediction of gasifier performance. While the turbulent multiphase reacting flow inside entrained-flow gasifiers has been modeled through computational fluid dynamic (CFD), the accuracy of sub-models requires further improvement. Built upon a previously developed CFD model for entrained-flow gasification, the advanced physical and chemical sub-models presented here include a moisture vaporization model with consideration of high mass transfer rate, a coal devolatilization model with more species to represent coal volatiles and heating rate effect on volatile yield, and careful selection of global gas phase reaction kinetics. The enhanced CFD model is applied to simulate two typical oxygen-blown entrained-flow configurations including a single-stage down-fired gasifier and a two-stage up-fired gasifier. The CFD results are reasonable in terms of predicted carbon conversion, syngas exit temperature, and syngas exit composition. The predicted profiles of velocity, temperature, and species mole fractions inside the entrained-flow gasifier models show trends similar to those observed in a diffusion-type flame. The predicted distributions of mole fractions of major species inside both gasifiers can be explained by the heterogeneous combustion and gasification reactions and the homogeneous gas phase reactions. It was also found that the syngas compositions at the CFD model exits are not in chemical equilibrium, indicating the kinetics for both heterogeneous and gas phase homogeneous reactions are important. Overall, the results achieved here indicate that the gasifier models reported in this paper are reliable and accurate enough to be incorporated into process/CFD co-simulations of IGCC power plants for systemwide design and optimization.

Ma, J.; Zitney, S.

2012-01-01T23:59:59.000Z

256

Improving the Modeling of Hydrogen Solubility in Heavy Oil Cuts Using an Augmented  

E-Print Network (OSTI)

Improving the Modeling of Hydrogen Solubility in Heavy Oil Cuts Using an Augmented Grayson Streed -- Improving the Modeling of Hydrogen Solubility in Heavy Oil Cuts Using an Augmented Grayson Streed (AGS for calculating hydrogen solubility in petroleum fluids. However, its accuracy becomes very bad when very heavy

Paris-Sud XI, Université de

257

Learning with Probabilistic Features for Improved Pipeline Models Razvan C. Bunescu  

E-Print Network (OSTI)

Learning with Probabilistic Features for Improved Pipeline Models Razvan C. Bunescu School of EECS for pipeline models aimed at improving the com- munication between consecutive stages in a pipeline. Our method exploits the confidence scores associated with outputs at any given stage in a pipeline in order to compute

Bunescu, Razvan C.

258

Carbon-nitrogen interactions regulate climate-carbon cycle feedbacks: results from an atmosphere-ocean general circulation model  

E-Print Network (OSTI)

Biogeosciences, 6, 20992120, 2009 www.biogeosciences.net/6/2099/2009/ Author(s) 2009. This work is distributed under the Creative Commons Attribution 3.0 License. Biogeosciences Carbon-nitrogen interactions regulate climate-carbon cycle feedbacks.... Inclusion of fundamental ecological interactions between carbon and nitrogen cycles in the land component of an atmosphere-ocean general circulation model (AOGCM) leads to decreased carbon uptake associated with CO2 fertil- ization, and increased carbon...

Thornton, P. E.; Doney, S. C.; Lindsay, Keith; Moore, J. K.; Mahowald, N. M.; Randerson, J. T.; Fung, I.; Lamarque, J. F.; Feddema, Johannes J.

2009-01-01T23:59:59.000Z

259

Improvements to the SHDOM Radiative Transfer Modeling Package  

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

to the SHDOM Radiative Transfer Modeling Package K. F. Evans University of Colorado Boulder, Colorado W. J. Wiscombe National Aeronautics and Space Administration...

260

Improved Usage Model for Web Application Reliability Testing .  

E-Print Network (OSTI)

??Testing the reliability of an application usually requires a good usage model that accurately captures the likely sequences of inputs that the application will receive (more)

Wan, Bo

2012-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "improving atmospheric models" 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

NREL: News - NREL Model Licensed to Improve Accuracy of Battery...  

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

NREL is a recognized leader in vehicle energy storage R&D. In addition to groundbreaking thermal evaluation and analysis, NREL's energy storage modeling, simulation, and testing...

262

ARM - Field Campaign - Single Column Model IOP  

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

applications: 1. Routine measurement of atmospheric state for assimilation into numerical weather prediction (NWP) model analyses. This would substantially improve the analyses and...

263

Estimates of Radioxenon Released from Southern Hemisphere Medical isotope Production Facilities Using Measured Air Concentrations and Atmospheric Transport Modeling  

SciTech Connect

Abstract The International Monitoring System (IMS) of the Comprehensive-Nuclear-Test-Ban-Treaty monitors the atmosphere for radioactive xenon leaking from underground nuclear explosions. Emissions from medical isotope production represent a challenging background signal when determining whether measured radioxenon in the atmosphere is associated with a nuclear explosion prohibited by the treaty. The Australian Nuclear Science and Technology Organisation (ANSTO) operates a reactor and medical isotope production facility in Lucas Heights, Australia. This study uses two years of release data from the ANSTO medical isotope production facility and Xe-133 data from three IMS sampling locations to estimate the annual releases of Xe-133 from medical isotope production facilities in Argentina, South Africa, and Indonesia. Atmospheric dilution factors derived from a global atmospheric transport model were used in an optimization scheme to estimate annual release values by facility. The annual releases of about 6.81014 Bq from the ANSTO medical isotope production facility are in good agreement with the sampled concentrations at these three IMS sampling locations. Annual release estimates for the facility in South Africa vary from 1.21016 to 2.51016 Bq and estimates for the facility in Indonesia vary from 6.11013 to 3.61014 Bq. Although some releases from the facility in Argentina may reach these IMS sampling locations, the solution to the objective function is insensitive to the magnitude of those releases.

Eslinger, Paul W.; Friese, Judah I.; Lowrey, Justin D.; McIntyre, Justin I.; Miley, Harry S.; Schrom, Brian T.

2014-04-06T23:59:59.000Z

264

Status and Improvements of Coupled General Circulation Models  

Science Journals Connector (OSTI)

...change impacts; and (iv) be a firmer basis for Earth system models that describe the feedbacks of societies to climate...change impacts; and (iv) be a firmer basis for Earth system models that describe the feedbacks of societies to climate...

Hartmut Grassl

2000-06-16T23:59:59.000Z

265

Transient Response of the Hadley Centre Coupled Ocean-Atmosphere Model to Increasing Carbon Dioxide. Part II: Spatial and Temporal Structure of Response  

Science Journals Connector (OSTI)

A high-resolution (2.75 lat 3.75 long) coupled ocean-atmosphere model has been used to simulate the transient response of climate to a gradual increase in atmospheric carbon dioxide concentrations. Although the radiative forcing increases ...

J. M. Murphy; J. F. B. Mitchell

1995-01-01T23:59:59.000Z

266

ATMOSPHERIC DENSITY ESTIMATION USING SATELLITE PRECISION ORBIT EPHEMERIDES  

E-Print Network (OSTI)

The current atmospheric density models are not capable enough to accurately model the atmospheric density, which varies continuously in the upper atmosphere mainly due to the changes in solar and geomagnetic activity. Inaccurate atmospheric modeling...

Arudra, Anoop Kumar

2011-04-22T23:59:59.000Z

267

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

E-Print Network (OSTI)

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

268

Improved di-neutron cluster model for 6He scattering  

E-Print Network (OSTI)

The structure of the three-body Borromean nucleus 6He is approximated by a two-body di-neutron cluster model. The binding energy of the 2n-\\alpha system is determined to obtain a correct description of the 2n-\\alpha coordinate, as given by a realistic three-body model calculation. The model is applied to describe the break-up effects in elastic scattering of 6He on several targets, for which experimental data exist. We show that an adequate description of the di-neutron-core degree of freedom permits a fairly accurate description of the elastic scattering of 6He on different targets.

A. M. Moro; K. Rusek; J. M. Arias; J. Gomez-Camacho; M. Rodriguez-Gallardo

2007-03-01T23:59:59.000Z

269

Improving sound propagation modeling for wind power projects  

Science Journals Connector (OSTI)

Sound propagation from wind power projects can be modeled in the same manner as other more common outdoor noisesources but are these models suited to wind turbines' uniquely high source heights operating under high wind conditions and various degrees of terrain ruggedness. In "Propagation Modeling Parameters for Wind Turbines" (K. Kaliski and E. Duncan Proceedings of Institute of Noise ControlEngineers NOISECON 2007) the effects of ground attenuation and various adjustments for wind conditions on sound propagationmodeling were discussed. This paper continues the discussion and explores the accuracy of existing sound propagationmodeling methods for wind power projects including ISO 9613 and other standards. Model data for wind power projects and the implications of various terrain and ground coverage will be discussed.

Eddie Duncan; Kenneth Kaliski

2008-01-01T23:59:59.000Z

270

Improved Model Formulations for Multi-Period Hydrogen Network Designs  

Science Journals Connector (OSTI)

Operating cost reduction and/or air pollution abatement via hydrogen integration is a research issue that has recently attracted considerable attention in the petroleum refining industries. Although a number of mathematical programming models have been ...

Che-Chi Kuo; Chuei-Tin Chang

2014-12-05T23:59:59.000Z

271

Evaluation of the Atmospheric Transport Model in the MACCS2 Code and its Impact on Decision Making at DOE Sites  

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

the Atmospheric the Atmospheric Transport Model in the MACCS2 Code and its Impact on Decision Making at Department of Energy Sites John E. Till and Arthur S. Rood June 5, 2012 RAC Historical Dose Reconstruction Projects Environmental Risk Assessment "Understanding and communicating the movement of radionuclides and chemicals released to the environment, resulting exposure to humans, and the subsequent dose or risk from exposure." Types of Dose/Risk  Medical  Occupational  Public Dose/Risk Can Be Estimated for  Real people  Hypothetical people Purpose of Assessments  Compliance  Decision making  Epidemiology  Emergency response Approaches to Estimating Risk  In certain situations, and depending upon the decisions to be made, if the results of relatively

272

Sensitivities of zonal mean atmospheric circulation to SST warming in an aquaplanet model  

E-Print Network (OSTI)

warming, the Hadley cell is intensified in the deep tropics, yet the Hadley cell boundary contracts, storm tracks, or the boundaries of Hadley cell circulations under global warming [e.g., Yin, 2005]. In the troposphere, however, the atmosphere displays nearly opposite changes in the Hadley cell width

Chen, Gang

273

ERDC TN-EMRRP-EBA-5 Improving Conceptual Model  

E-Print Network (OSTI)

's goals and stakeholders' expectations. In aquatic ecosystem restoration projects, these often include model is a required step in creating any ecosystem restoration project plan regardless of project size available through the Ecosystem Restoration Gateway (http://cw-environment.usace. army.mil/restoration

US Army Corps of Engineers

274

TransCom N[subscript 2]O model inter-comparison Part 2: Atmospheric inversion estimates of N[subscript 2]O emissions  

E-Print Network (OSTI)

This study examines N[subscript 2]O emission estimates from five different atmospheric inversion frameworks based on chemistry transport models (CTMs). The five frameworks differ in the choice of CTM, meteorological data, ...

Thompson, R. L.

275

Large-Eddy Simulation of Stratified Turbulence. Part II: Application of the Stretched-Vortex Model to the Atmospheric Boundary Layer  

Science Journals Connector (OSTI)

The buoyancy-adjusted stretched-vortex subgrid-scale (SGS) model is assessed for a number of large-eddy simulations (LESs) corresponding to diverse atmospheric boundary layer conditions. The cases considered are free convection, a moderately ...

Georgios Matheou; Daniel Chung

2014-12-01T23:59:59.000Z

276

Two-Temperature Two-Dimensional Non Chemical Equilibrium Modeling of ArCO2H2 Induction Thermal Plasmas at Atmospheric Pressure  

Science Journals Connector (OSTI)

Here the authors developed a two-dimensional two-temperature chemical non-equilibrium (2T-NCE) model of Ar...2H2 inductively coupled thermal plasmas (ICTP) around atmospheric pressure (760torr). Assuming 22 di...

Sharif Abdullah Al-Mamun; Yasunori Tanaka

2010-02-01T23:59:59.000Z

277

Transient Response of the Hadley Centre Coupled Ocean-Atmosphere Model to Increasing Carbon Dioxide. Part 1: Control Climate and Flux Adjustment  

Science Journals Connector (OSTI)

This paper describes the initialization of an experiment to study the time-dependent response of a high-resolution global coupled ocean-atmosphere general circulation model to a gradual increase in carbon dioxide. The stability of the control ...

J. M. Murphy

1995-01-01T23:59:59.000Z

278

The Dynamical Core, Physical Parameterizations, and Basic Simulation Characteristics of the Atmospheric Component AM3 of the GFDL Global Coupled Model CM3  

Science Journals Connector (OSTI)

The Geophysical Fluid Dynamics Laboratory (GFDL) has developed a coupled general circulation model (CM3) for the atmosphere, oceans, land, and sea ice. The goal of CM3 is to address emerging issues in climate change, including aerosolcloud ...

Leo J. Donner; Bruce L. Wyman; Richard S. Hemler; Larry W. Horowitz; Yi Ming; Ming Zhao; Jean-Christophe Golaz; Paul Ginoux; S.-J. Lin; M. Daniel Schwarzkopf; John Austin; Ghassan Alaka; William F. Cooke; Thomas L. Delworth; Stuart M. Freidenreich; C. T. Gordon; Stephen M. Griffies; Isaac M. Held; William J. Hurlin; Stephen A. Klein; Thomas R. Knutson; Amy R. Langenhorst; Hyun-Chul Lee; Yanluan Lin; Brian I. Magi; Sergey L. Malyshev; P. C. D. Milly; Vaishali Naik; Mary J. Nath; Robert Pincus; Jeffrey J. Ploshay; V. Ramaswamy; Charles J. Seman; Elena Shevliakova; Joseph J. Sirutis; William F. Stern; Ronald J. Stouffer; R. John Wilson; Michael Winton; Andrew T. Wittenberg; Fanrong Zeng

2011-07-01T23:59:59.000Z

279

Modeling distributions of stem characteristics of genetically improved loblolly pine  

E-Print Network (OSTI)

presented in this study. N de 'n th Parame s Once the parameter estimates for each plot had been computed for the chosen distribution, multiple regression techniques were utilized to relate the parameter estimates to stand characteristics. Regression... best characterized the data. Models were subsequently developed to predict the diameter, height, and volume distributions using the moment-based beta probability density function. The probability density function parameters were predicted from stand...

Janssen, Jill Elizabeth

1988-01-01T23:59:59.000Z

280

BLACK-BOX MODELLING OF HVAC SYSTEM: IMPROVING THE PERFORMANCES OF NEURAL NETWORKS  

E-Print Network (OSTI)

BLACK-BOX MODELLING OF HVAC SYSTEM: IMPROVING THE PERFORMANCES OF NEURAL NETWORKS Eric FOCK Ile de La Réunion - FRANCE ABSTRACT This paper deals with neural networks modelling of HVAC systems of HVAC system can be modelled using manufacturer design data presented as derived performance maps

Boyer, Edmond

Note: This page contains sample records for the topic "improving atmospheric models" 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

Improving Efficiency of Data Assimilation Procedure for a Biomechanical Heart Model by  

E-Print Network (OSTI)

Improving Efficiency of Data Assimilation Procedure for a Biomechanical Heart Model by Representing to perform parameter estimation in a biomechanical model of the heart using synthetic observations [1, 3, 7, 8, 12, 15, 16] as an es- sential tool in heart modeling in order to personalize from

Paris-Sud XI, Université de

282

Detecting anthropogenic influences on climate with an atmospheric model forced with observed variations in sea surface temperature  

SciTech Connect

Six ensembles of four simulations with the Hadley Centre atmospheric general circulation model (HADAM2a) have been carried out for late 1948 to the end of 1994 with different specified atmospheric forcing distributions. These simulations are being used to understand the role of different forcing processes in determining the observed climate variations during the second half of the twentieth century. All ensembles started from different initial conditions and were forced with specified global observed monthly sea ice and sea surface temperature distributions using the GISST1.1 data set. The approach used deterministic sampling of observed variations in climate rather than a coupled model. The technique was also different in that it looked at the smaller residual climate signal due to direct anthropogenic over and above those captured in ocean surface temperatures. The results indicate that this method is a useful complement to approaches based on coupled models, aided by the fact that some of the residual climate signals are almost as large as the full signals seen in coupled models, particularly in the stratosphere. 9 refs., 4 figs.

Folland, C.K.; Sexton, D. [Hadley Centre, Bracknell (United Kingdom); Karoly, D. [Monash Univ., Victoria (Australia)] [and others

1997-11-01T23:59:59.000Z

283

Causes and implications of persistent atmospheric carbon dioxide biases in Earth System Models  

E-Print Network (OSTI)

2013), The Community Earth System Model: A framework forin the Norwegian Earth System Model (NorESM), Geosci. Modelsimulations from CMIP5 Earth system models and comparison

2014-01-01T23:59:59.000Z

284

Dark Stars: Improved Models and First Pulsation Results  

E-Print Network (OSTI)

(Abridged) We use the stellar evolution code MESA to study dark stars. Dark stars (DSs), which are powered by dark matter (DM) self-annihilation rather than by nuclear fusion, may be the first stars to form in the Universe. We compute stellar models for accreting DSs with masses up to 10^6 M_sun. While previous calculations were limited to polytropic interiors, our current calculations use MESA, a modern stellar evolution code to solve the equations of stellar structure. The heating due to DM annihilation is self-consistently included, assuming extended adiabatic contraction of DM within the minihalos in which DSs form. We find remarkably good overall agreement with the basic results of previous models. There are some differences, however, in the details, with positive implications for observability of DSs. We found that, in the mass range of 10^4 - 10^5 M_sun, using MESA, our DSs are hotter by a factor of 1.5 than those in Freese et al.(2010), are smaller in radius by a factor of 0.6, denser by a factor of 3...

Rindler-Daller, Tanja; Freese, Katherine; Winget, Donald E; Paxton, Bill

2014-01-01T23:59:59.000Z

285

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

E-Print Network (OSTI)

A variety of improvements to the MIT Design Advisor, a whole-building energy usage modeling tool intended for use during early design stages, are investigated. These include changes to the thermal mass temperature distribution ...

Mandelbaum, Andrew (Andrew Joseph)

2014-01-01T23:59:59.000Z

286

Improvements to Hydrogen Delivery Scenario Analysis Model (HDSAM) and Results  

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

to Hydrogen to Hydrogen Delivery Scenario Analysis Model (HDSAM) and Results May 8, 2007 Amgad Elgowainy Argonne National Laboratory Comparison of Delivery Pathways- V1.0 vs. V2.0 2 1 3 i delivery by a Loading, the plant Version 1.0 character zed components for 3 pathways with single mode. conditioning and storage are at or adjacent to Liquid Hydrogen (LH) Truck H2 Production 100 or 1500 kg/d Compressed H2 (CH) Truck H2 Production 3 or 7 kpsi 100 or 1500 kg/d H2 Production Gaseous H2 Pipeline 100 or 1500 kg/d HDSAM V1.0 Estimates Delivery Cost for 3 Pathways 4 H2 H2 1 2 3 H2 Distribution and Ci I. Liquid H2 Distribution: HDSAM V2.0 Simulates Nine Pathways Production Production LH Terminal LH Terminal Production LH Terminal Transmission Transmission Distribution

287

Improved user interface design for site selection modeling system  

SciTech Connect

The Site Selection Modeling System (SSMS) is a customized application within the Environmental Data Atlas (EDA), which is an integrated geographic information system (GIS) for environmental applications at the Savannah River site (SRS) developed jointly by the Environmental Sciences Section (ESS) of Westinghouse Savannah River Company and by the University of South Carolina (USC). The SSMS was developed to assist analysts with site selection activities carried out by the ESS and is a powerful tool with a graphical user interface that allows non-GIS analysts to use the application. However, use of the SSMS in recent siting exercises revealed deficiencies in the user interface as a production tool. This paper specifies user interface design criteria necessary for a production application and describes the implementation of these design criteria in the SSMS.

Koffman, L.D. [Westinghouse Savannah River Site, Aiken, SC (United States)

1996-12-31T23:59:59.000Z

288

RESIDUA UPGRADING EFFICIENCY IMPROVEMENT MODELS: COKE FORMATION PREDICTABILITY MAPS  

SciTech Connect

The dispersed particle solution model of petroleum residua structure was used to develop predictors for pyrolytic coke formation. Coking Indexes were developed in prior years that measure how near a pyrolysis system is to coke formation during the coke formation induction period. These have been demonstrated to be universally applicable for residua regardless of the source of the material. Coking onset is coincidental with the destruction of the ordered structure and the formation of a multiphase system. The amount of coke initially formed appears to be a function of the free solvent volume of the original residua. In the current work, three-dimensional coke make predictability maps were developed at 400 C, 450 C, and 500 C (752 F, 842 F, and 932 F). These relate residence time and free solvent volume to the amount of coke formed at a particular pyrolysis temperature. Activation energies for two apparent types of zero-order coke formation reactions were estimated. The results provide a new tool for ranking residua, gauging proximity to coke formation, and predicting initial coke make tendencies.

John F. Schabron; A. Troy Pauli; Joseph F. Rovani Jr.

2002-05-01T23:59:59.000Z

289

Atmospheric Environment 38 (2004) 44274436 Statistical comparison of observed and CMAQ modeled daily  

E-Print Network (OSTI)

2004 Abstract New statistical procedures to evaluate the Models-3/Community Multiscale Air Quality reserved. Keywords: Air quality model; Model evaluation; Space­time process; Separable covariance function 1. Introduction The Models-3/Community Multiscale Air Quality (CMAQ) modeling system has been

Jun, Mikyoung

290

Development of a GPU-based high-performance radiative transfer model for the Infrared Atmospheric Sounding Interferometer (IASI)  

SciTech Connect

Satellite-observed radiance is a nonlinear functional of surface properties and atmospheric temperature and absorbing gas profiles as described by the radiative transfer equation (RTE). In the era of hyperspectral sounders with thousands of high-resolution channels, the computation of the radiative transfer model becomes more time-consuming. The radiative transfer model performance in operational numerical weather prediction systems still limits the number of channels we can use in hyperspectral sounders to only a few hundreds. To take the full advantage of such high-resolution infrared observations, a computationally efficient radiative transfer model is needed to facilitate satellite data assimilation. In recent years the programmable commodity graphics processing unit (GPU) has evolved into a highly parallel, multi-threaded, many-core processor with tremendous computational speed and very high memory bandwidth. The radiative transfer model is very suitable for the GPU implementation to take advantage of the hardware's efficiency and parallelism where radiances of many channels can be calculated in parallel in GPUs. In this paper, we develop a GPU-based high-performance radiative transfer model for the Infrared Atmospheric Sounding Interferometer (IASI) launched in 2006 onboard the first European meteorological polar-orbiting satellites, METOP-A. Each IASI spectrum has 8461 spectral channels. The IASI radiative transfer model consists of three modules. The first module for computing the regression predictors takes less than 0.004% of CPU time, while the second module for transmittance computation and the third module for radiance computation take approximately 92.5% and 7.5%, respectively. Our GPU-based IASI radiative transfer model is developed to run on a low-cost personal supercomputer with four GPUs with total 960 compute cores, delivering near 4 TFlops theoretical peak performance. By massively parallelizing the second and third modules, we reached 364x speedup for 1 GPU and 1455x speedup for all 4 GPUs, both with respect to the original CPU-based single-threaded Fortran code with the -O{sub 2} compiling optimization. The significant 1455x speedup using a computer with four GPUs means that the proposed GPU-based high-performance forward model is able to compute one day's amount of 1,296,000 IASI spectra within nearly 10 min, whereas the original single CPU-based version will impractically take more than 10 days. This model runs over 80% of the theoretical memory bandwidth with asynchronous data transfer. A novel CPU-GPU pipeline implementation of the IASI radiative transfer model is proposed. The GPU-based high-performance IASI radiative transfer model is suitable for the assimilation of the IASI radiance observations into the operational numerical weather forecast model.

Huang Bormin, E-mail: bormin@ssec.wisc.ed [Space Science and Engineering Center, University of Wisconsin, Madison (United States); Mielikainen, Jarno [Department of Computer Science, University of Eastern Finland, Kuopio (Finland); Oh, Hyunjong; Allen Huang, Hung-Lung [Space Science and Engineering Center, University of Wisconsin, Madison (United States)

2011-03-20T23:59:59.000Z

291

Coupling Chemical Transport Model Source Attributions with Positive Matrix Factorization: Application to Two IMPROVE Sites Impacted by Wildfires  

Science Journals Connector (OSTI)

Coupling Chemical Transport Model Source Attributions with Positive Matrix Factorization: Application to Two IMPROVE Sites Impacted by Wildfires ... Cooperative

Timothy M. Sturtz; Bret A. Schichtel; Timothy V. Larson

2014-09-02T23:59:59.000Z

292

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

E-Print Network (OSTI)

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

Sokolov, Andrei P.

293

Causes and implications of persistent atmospheric carbon dioxide biases in Earth System Models  

E-Print Network (OSTI)

Intercomparison Project indicated that climate models oftenpled ClimateCarbon Cycle Model Intercomparison Project (C 4BIOFEEDBACK project of the Center for Climate Dynamics (SKD)

2014-01-01T23:59:59.000Z

294

Analysis of mid-tropospheric carbon monoxide data using a three- dimensional Global atmospheric Chemistry numerical Model  

SciTech Connect

The GChM atmospheric chemistry and transport model has been used to analyze the mid-tropospheric CO dataset obtained from NASA`s Measurement of Air Pollution by Satellites (MAPS) program. Fourteen simulations with a 3.75 horizontal resolution have been performed, including a base case and 13 sensitivity runs. The model reproduces many, but not all, of the major features of the MAPS dataset. Locations of peak CO mixing ratios associated with biomass burning as observed in the MAPS experiment are slightly farther south than the model result, indicating either greater horizontal transport than present in the model representation or a spatial difference between the location of modeled biomass fires and actual fires. The current version of GChM was shown to be relatively insensitive to the magnitude of the prescribed NO{sub x} and O{sub 3} global distributions and very insensitive to the depth of the mixed layer as parameterized in the model. Cloud convective transport was shown to play an important role in venting boundary layer CO to the free troposphere. This result agrees with prior meteorological analyses of the MAPS dataset that have-indirectly inferred the presence of convective activity through satellite-based information. Work is continuing to analyze the results of these simulations further and to perform more detailed comparisons between model results and MAPS data.

Easter, R.C.; Saylor, R.D.; Chapman, E.G.

1993-12-01T23:59:59.000Z

295

Modelling of CO2 content in the atmosphere until 2300: influence of energy intensity of gross domestic product and carbon intensity of energy  

Science Journals Connector (OSTI)

The study provides a model of CO2 content in the atmosphere based on the global carbon cycle and the Kaya identity. The influences of: 1) energy intensity of GDP; 2) carbon intensity of energy on CO2 trajectories are given under four scenarios. The results from the most optimistic and technologically challenging scenario show that the atmospheric CO2 concentration can stabilise at 610 ppmv. It is also shown that the annual growth rates of atmospheric CO2 peak for all the scenarios before 2100 due to the expected world population peak in 2075 and the large share of fossil fuel energy.

Wojciech M. Budzianowski

2013-01-01T23:59:59.000Z

296

Computational Modeling of Ballast Tanks to Improve Understanding and Maximize Effectiveness of Management Practices and Treatment  

E-Print Network (OSTI)

Computational Modeling of Ballast Tanks to Improve Understanding and Maximize Effectiveness tanks exchange coastal ballast water with mid-ocean seawater (referred to as "ballast water exchange of high-resolution computational fluid dynamics (CFD) to model ballast tank water flow and to predict EE

297

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

E-Print Network (OSTI)

the dependency of an electronic system to primary energy sources (i.e. AC power or battery). For reliable energy generation and consumption parameters. The system uses economics inspired supply-demand modelA Supply-Demand Model Based Scalable Energy Management System for Improved Energy Utilization

Bhunia, Swarup

298

Improving the Production Efficiency of Beef Cows through Mathematical Modeling and Genomics  

E-Print Network (OSTI)

Improving the Production Efficiency of Beef Cows through Mathematical Modeling and Genomics that integrating recent advances in genomics, the identification of intrinsic genetic factors that determine and evaluate the individual-based model for production efficiency· of beef cows using genomic and biomarker

299

THE CARBON-LAND MODEL INTERCOMPARISON PROJECT (C-LAMP): A PROTOTYPE FOR COUPLED BIOSPHERE-ATMOSPHERE MODEL  

E-Print Network (OSTI)

often referred to as Earth System Models (ESMs). While a number of terrestrial and ocean carbon models

Hoffman, Forrest M.

300

Equivalent circuit-level model and improvement of terahertz quantum cascade lasers  

Science Journals Connector (OSTI)

An equivalent circuit-level model of terahertz (THz) quantum cascade lasers (QCLs) is developed by using rate equations. This model can be employed to investigate the characteristics of THz QCLs accurately and to improve their design. We use the circuit-level model to analyse a new active structure, which can improve the performance of THz QCLs by means of enhancing carrier injection. The simulation result shows that THz QCLs with the new active structure have a much higher performance compared with conventional THz QCLs. The high-performance THz QCLs are expected to be operated at higher temperatures.

Wei Zhou; Shaobin Liu; Jie Wu; Xiaoliu Zhang; Wu Tang

2014-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "improving atmospheric models" 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

Atmospheric and Climate Science | Argonne National Laboratory  

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

Atmospheric and Climate Science Atmospheric and Climate Science Argonne research in aerosols, micro-meteorology, remote sensing, and atmospheric chemistry combined with our scalable, portable, high-performance climate and weather applications offer a unique look at the complexities of a dynamic planet. Changes in climate can affect biodiversity, the cost of food, our health, and even whole economies. Argonne is developing computational models and tools designed to shed light on complex biological processes and their economic, social, and health effects. Research spans the molecular level to whole organisms and their interaction with climate, the ecosystem, and human activities. The goal is to improve our understanding of the world around us while increasing the accuracy of regional climate models to

302

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

E-Print Network (OSTI)

into the numerical weather prediction model COSMO, BorealCurrent numerical weather prediction (NWP) models, regionalof lakes in numerical weather prediction and climate models:

Subin, Z.M.

2013-01-01T23:59:59.000Z

303

Three-dimensional Atmospheric Circulation Models of HD 189733b and HD 209458b with Consistent Magnetic Drag and Ohmic Dissipation  

Science Journals Connector (OSTI)

We present the first three-dimensional circulation models for extrasolar gas giant atmospheres with geometrically and energetically consistent treatments of magnetic drag and ohmic dissipation. Atmospheric resistivities are continuously updated and calculated directly from the flow structure, strongly coupling the magnetic effects with the circulation pattern. We model the hot Jupiters HD 189733b (T eq ? 1200K) and HD 209458b (T eq ? 1500K) and test planetary magnetic field strengths from 0 to 30G. We find that even at B = 3G the atmospheric structure and circulation of HD 209458b are strongly influenced by magnetic effects, while the cooler HD 189733b remains largely unaffected, even in the case of B = 30G and super-solar metallicities. Our models of HD 209458b indicate that magnetic effects can substantially slow down atmospheric winds, change circulation and temperature patterns, and alter observable properties. These models establish that longitudinal and latitudinal hot spot offsets, day-night flux contrasts, and planetary radius inflation are interrelated diagnostics of the magnetic induction process occurring in the atmospheres of hot Jupiters and other similarly forced exoplanets. Most of the ohmic heating occurs high in the atmosphere and on the dayside of the planet, while the heating at depth is strongly dependent on the internal heat flux assumed for the planet, with more heating when the deep atmosphere is hot. We compare the ohmic power at depth in our models, and estimates of the ohmic dissipation in the bulk interior (from general scaling laws), to evolutionary models that constrain the amount of heating necessary to explain the inflated radius of HD 209458b. Our results suggest that deep ohmic heating can successfully inflate the radius of HD 209458b for planetary magnetic field strengths of B ? 3-10G.

Emily Rauscher; Kristen Menou

2013-01-01T23:59:59.000Z

304

Improved low-order model for shear flow driven by Rayleigh-Benard convection  

SciTech Connect

An analysis of the low-order model for two-dimensional fluid flow with shear proposed by Drake [ital et] [ital al]. [Phys. Fluids B 4, 488 (1992)] is undertaken. Their two-term model for the shear is an extension of the model put forth by Howard and Krisnamurti [J. Fluid Mech. 170, 385 (1986)], and is shown to be an improved model in the sense that it respects certain conditions for vorticity conservation arising directly from the Boussinesq equations. In so doing, it provides a more realistic model of the physics involved. An important consequence of the improved model is the appearance of cutoff values for the shear instability that are dependent upon the aspect ratio of the interacting Rayleigh-Taylor cell. Numerical results are presented as confirmation of this prediction.

Hermiz, K.B. (Department of Mathematics, University of Maryland, College Park, Maryland 20742-3511 (United States)); Guzdar, P.N.; Finn, J.M. (Institute for Plasma Research, University of Maryland, College Park, Maryland 20742-3511 (United States))

1995-01-01T23:59:59.000Z

305

Final Report on the Development of an Improved Cloud Microphysical Product for Model and Remote Sensing Evaluation using RACORO Observations  

SciTech Connect

We proposed to analyze data collected during the Routine Aerial Facilities (AAF) Clouds with Low Optical Water Depths (CLOWD) Optical Radiative Observations (RACORO) in order to develop an integrated product of cloud microphysical properties (number concentration of drops in different size bins, total liquid drop concentration integrated over all bin sizes, liquid water content LWC, extinction of liquid clouds bw, effective radius of water drops re, and radar reflectivity factor) that could be used to evaluate large-eddy simulations (LES), general circulation models (GCMs) and ground-based remote sensing retrievals, and to develop cloud parameterizations with the end goal of improving the modeling of cloud processes and properties and their impact on atmospheric radiation. We have completed the development of this microphysical database and have submitted it to ARM for consideration of its inclusion on the ARM database as a PI product. This report describes the development of this database, and also describes research that has been conducted on cloud-aerosol interactions using the data obtained during RACORO. A list of conference proceedings and publications is also included.

McFarquhar, Greg

2012-09-19T23:59:59.000Z

306

Improvement of modelling capabilities for assessing urban contamination : The EMRAS Urban Remediation Working Group.  

SciTech Connect

The Urban Remediation Working Group of the International Atomic Energy Agency's Environmental Modeling for Radiation Safety (EMRAS) programme was established to improve modeling and assessment capabilities for radioactively contaminated urban situations, including the effects of countermeasures. An example of the Working Group's activities is an exercise based on Chernobyl fallout data in Ukraine, which has provided an opportunity to compare predictions among several models and with available measurements, to discuss reasons for discrepancies, and to identify areas where additional information would be helpful.

Thiessen, K. M.; Batandjieva, B.; Andersson, K. G.; Arkhipov, A.; Charnock, T. W.; Gallay, F.; Gaschak, S.; Golikov, V.; Hwang, W. T.; Kaiser, J. C.; Kamboj, S.; Steiner, M.; Tomas, J.; Trifunovic, D.; Yu, C.; Ziemer, R. L.; Zlobenko, B.; Environmental Science Division; SENES Oak Ridge; IAEA; Riso National Lab.; Chernobyl Center for Nuclear Safety; Health Protection Agency; IRSN; Inst. of Radiation Hygene of the Ministry of Public Health, Russian Federation; KAERI, Republic of Korea; GSF, Germany; BfS, Germany; CPHR, Cuba; State Office for Radiation Protection, Croatia; AECL, Canada; National Academy of Science, Ukraine

2008-01-01T23:59:59.000Z

307

Millimeter radiation from a 3D model of the solar atmosphere I. Diagnosing chromospheric thermal structure  

E-Print Network (OSTI)

Aims. We use advanced 3D NLTE radiative magnetohydrodynamic simulations of the solar atmosphere to carry out detailed tests of chromospheric diagnostics at millimeter and submillimeter wavelengths. Methods. We focused on the diagnostics of the thermal structure of the chromosphere in the wavelength bands from 0.4 mm up to 9.6 mm that can be accessed with the Atacama Large Millimeter/Submillimeter Array (ALMA) and investigated how these diagnostics are affected by the instrumental resolution. Results. We find that the formation height range of the millimeter radiation depends on the location in the simulation domain and is related to the underlying magnetic structure. Nonetheless, the brightness temperature is a reasonable measure of the gas temperature at the effective formation height at a given location on the solar surface. There is considerable scatter in this relationship, but this is significantly reduced when very weak magnetic fields are avoided. Our results indicate that although instrumental smearin...

Loukitcheva, Maria; Carlsson, Mats; White, Stephen

2015-01-01T23:59:59.000Z

308

EMEP Intercomparison Study of Numerical Models for Long-Range Atmospheric Transport of Mercury  

E-Print Network (OSTI)

............................... Denmark...NERI G. Petersen, R. Ebinghaus .................. Germany...GKSS J. Pacyna and Oxidants Model, GKSS Research Center, GermanyADOM MSC-E heavy metal regional model, EMEP MSC

309

Assessment of Modes of Interannual Variability of Southern Hemisphere Atmospheric Circulation in CMIP5 Models  

Science Journals Connector (OSTI)

An assessment is made of the modes of interannual variability in the seasonal mean summer and winter Southern Hemisphere (SH) 500-hPa geopotential height in the twentieth century in models from the Coupled Model Intercomparison Project (CMIP) ...

Simon Grainger; Carsten S. Frederiksen; Xiaogu Zheng

2014-11-01T23:59:59.000Z

310

Atmospheric Environment 39 (2005) 13731382 A hierarchical Bayesian model to estimate and forecast ozone  

E-Print Network (OSTI)

reserved. Keywords: Statistical model; Space­time models; Air pollution; Ozone; Meteorology 1. Introduction describing the spatial­temporal behavior of ambient air pollutants such as ozone (O3) and particulate matter. Statistical space­time models are useful for illuminating relationships between different air pollutants

Irwin, Mark E.

311

Musical Atmospherics  

Science Journals Connector (OSTI)

... THE characteristics of audio musical atmospherics which are obtained when an ... musical atmospherics which are obtained when an audio amplifier is placed in a long line or aerial have been discussed from time to ...

T. L. ECKERSLEY

1935-01-19T23:59:59.000Z

312

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

E-Print Network (OSTI)

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

313

Improving capabilities for dealing with key complexities of water availability modeling  

E-Print Network (OSTI)

evaluates short term diversion/storage reliabilities based on an initial storage level. WRAP-CON has been evaluated and improved, in addition a new modeling methodology has been developed, in which probabilities of occurrence for each hydrologic sequence... is based on the relationship between storage and future flows. Recently developed WRAP capabilities have been evaluated, providing users new tools and increased flexibility. Some of these improvements are firm yield analysis, cycling and dual simulation...

Olmos Alejo, Hector Elias

2005-02-17T23:59:59.000Z

314

Fiscal year 1997 summary report of the NOAA Atmospheric Sciences Modeling Division to the U.S. Environmental Protection Agency. Technical memo  

SciTech Connect

During Fiscal Year 1997, the Atmospheric Sciences Modeling Division provided meteorological and modeling support to the US Environmental Protection Agency. Research efforts emphasized the development and evaluation of air quality models using numerical and physical techniques supported by field studies. Among the significant research studies were the continued development and evaluation of Models-3; development of a community multiscale air quality modeling system; continued development and application of air quality models for mercury, dioxin, and heavy metals; evaluation of enhanced human exposure models; analysis and modeling of dust resuspension data; study of buoyant puff dispersion in the convective boundary layer; and development of methodologies to estimate the drift of airborne agricultural pesticides.

Poole-Kober, E.M.; Viebrock, H.J.

1998-06-01T23:59:59.000Z

315

Improved quasi-unary nucleation model for binary H 2 S O 4 H 2 O homogeneous nucleation  

Science Journals Connector (OSTI)

Aerosol nucleation events have been observed at a variety of locations worldwide and may have significant climatic and health implications. Binary homogeneous nucleation (BHN) of H 2 S O 4 and H 2 O is the foundation of recently proposed nucleation mechanisms involving additional species such as ammonia ions and organic compounds and it may dominate atmospheric nucleation under certain conditions. We have shown in previous work that H 2 S O 4 H 2 O BHN can be treated as a quasi-unary nucleation (QUN) process involving H 2 S O 4 in equilibrium with H 2 O vapor and we have developed a self-consistent kinetic model for H 2 S O 4 H 2 O nucleation. Here the QUN approach is improved and an analytical expression yielding H 2 S O 4 H 2 O QUN rates is derived. Two independent measurements related to monomer hydration are used to constrain the equilibrium constants for this process which reduces a major source of uncertainty. It is also shown that the capillarity approximation may lead to a large error in the calculated Gibbs free energy change for the evaporation of H 2 S O 4 molecules from small H 2 S O 4 H 2 O clusters which affects the accuracy of predicted BHN nucleation rates. The improved QUN modeltaking into account the recently measured energetics of small clustersis thermodynamically more robust. Moreover predicted QUN nucleation rates are in better agreement with available experimental data than rates calculated using classical H 2 S O 4 H 2 O BHN theory.

Fangqun Yu

2007-01-01T23:59:59.000Z

316

Using Information on Uncertainty to Improve Environmental Fate Modeling: A Case Study on DDT  

SciTech Connect

Present and future concentrations of DDT in the environment are calculated with the global multi-media model CliMoChem. Monte Carlo simulations are used to assess the importance of uncertainties in substance property data, emission rates, and environmental parameters for model results. Uncertainties in the model results, expressed as 95percent confidence intervals of DDT concentrations in various environmental media, in different geographical locations, and at different points in time are typically between one and two orders of magnitude. An analysis of rank correlations between model inputs and predicted DDT concentrations indicates that emission estimates and degradation rate constants, in particular in the atmosphere, are the most influential model inputs. For DDT levels in the Arctic, temperature dependencies of substance properties are also influential parameters. A Bayesian Monte Carlo approach is used to update uncertain model inputs based on measurements of DDT in the field. The updating procedure suggests a lower value for half-life in air and a reduced range of uncertainty for KOW of DDT. As could be expected, the Bayesian updating yields model results that are closer to observations, and model uncertainties have decreased. The combined sensitivity analysis and Bayesian Monte Carlo approach provide new insight into important processes that govern the global fate and persistence of DDT in the environment.

Schenker, Urs; Scheringer, Martin; Sohn, Michael D.; Maddalena, Randy L.; McKone, Thomas E.; Hungerbuhler, Konrad

2008-10-01T23:59:59.000Z

317

The Met Office Hadley Centre climate modelling capability: the competing requirements for improved resolution, complexity and dealing with uncertainty  

Science Journals Connector (OSTI)

...will be implemented in a model version in the HadGEM2 family and coupled to the atmospheric dust scheme. (h) Earth system models In order to understand the overall feedbacks of chemistry and ecosystems on climate, the relevant processes need...

2007-01-01T23:59:59.000Z

318

E-Print Network 3.0 - atmospheric model intercomparison Sample...  

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

Project, phase 1 (CMIP1... Abstract An intercomparison of eight EMICs (Earth system Models of Intermediate Complexity) is carried out... doubling in the ... Source:...

319

ATMOSPHERIC ELSEVIER AtmosphericResearch40 (1996) 223-259  

E-Print Network (OSTI)

of atmospheric aerosol particles and cloud hydrometeors (water drops, ice particles, and, particularlyATMOSPHERIC RESEARCH ELSEVIER AtmosphericResearch40 (1996) 223-259 Simulations of drop fall turbulence. The model permits us to generate different realizations of the random velocity field component

Mark, Pinsky

320

Development of an Adjoint for a Complex Atmospheric Model, the ARPS, using TAF  

E-Print Network (OSTI)

, such as operational weather predictions models, pose challenges on the applicability of AD tools. We report- ational weather prediction models are much more complex, and the problem sizes tend to be much larger as a system for mesoscale and storm-scale numerical weather prediction as well as a wide range of idealized

Gao, Jidong

Note: This page contains sample records for the topic "improving atmospheric models" 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

Addressing model error through atmospheric stochastic physical parametrizations: impact on the coupled ECMWF seasonal forecasting system  

Science Journals Connector (OSTI)

...parametrizations: impact on the coupled ECMWF...Stochastic modelling and energy-efficient computing...effects of sub-grid-scale variability...present results of the impact of these schemes...and near-surface winds. Positive impact...Stochastic modelling and energy-efficient computing...

2014-01-01T23:59:59.000Z

322

Toward self-describing and workflow integrated Earth system models: A coupled atmosphere-ocean modeling system application  

Science Journals Connector (OSTI)

The complexity of Earth system models and their applications is increasing as a consequence of scientific advances, user demand, and the ongoing development of computing platforms, storage systems and distributed high-resolution observation networks. ... Keywords: Coupled Earth system models, Provenance information, ROMS, Scientific workflow, Self-describing models, WRF

Ufuk Utku Turuncoglu; Nuzhet Dalfes; Sylvia Murphy; Cecelia Deluca

2013-01-01T23:59:59.000Z

323

Development of a computer model for calculation of radioactive materials into the atmosphere after an accident  

SciTech Connect

Secondary atmospheric contamination with radioactive dust and chemical species deposited on the ground and resuspended by wind occur very widely. This process is particularly pronounced in case of extensive contamination of soil and under extreme weather conditions, for example, during dust storms. The mechanism of wind dust generation consists in the following. At low wind speed U=2-3 m/s, which is most common in midlatitude, small radioactive dust particles (diameter of hundredth of a micron to 10-20 microns) are lifted from soil surface due to turbulent vortexes. Under the gravitational force the particles of 1-2 micron diameter practically do not settle. Larger dust particles cannot remain in the air for a long time: they are lifted by turbulent vortexes and settle, their motion in the wind flow is jump-wise and the interaction of particles with the flow is called saltation /I/. Saltation is the main mechanism of dust generation up to the wind velocity at which wind erosion starts. The size of dust particles can be as large as 100 pm. When dropping they can be ricocheting from ground or pass the impulse to other particles which begin rolling over and jumping up. The process of dust transport by wind can be compared to a chain reaction. At the velocity of 10 m/s large particles of about 500 pm stop skipping and roll over only, while particles of more than 1 mm remain stationary. Thus, the fine fraction is blown out from the polydispersed soil particles. The intensity of wind resuspension of radioactive dust from the ground is characterized either by a resuspension factor or a resuspension rate.

Schershakov, V. [Federal Information Analytical Centre, Obinski (Russia)

1997-11-01T23:59:59.000Z

324

Applying methods of numerical modeling to optimize a plasma burner of atmospheric pressure  

Science Journals Connector (OSTI)

The shape of a plasma burner is optimized by the methods of numerical modeling. Vortex-free flow is created in the burner merely at the expense of selecting the external tube profile rather than by introductio...

S. M. Perminov; V. N. Perminova

1993-09-01T23:59:59.000Z

325

Refining climate models  

SciTech Connect

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

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

2012-10-31T23:59:59.000Z

326

Refining climate models  

ScienceCinema (OSTI)

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

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

2014-06-26T23:59:59.000Z

327

Improving estimates of African woodland biomass by fusing radar data, models and ground observations  

E-Print Network (OSTI)

Improving estimates of African woodland biomass by fusing radar data, models and ground management of savannahs and woodlands requires accurate estimates of the woody biomass. For these reasons, developing new methods to accurately estimate woody biomass and its changes is high on the political

328

Improving Managed Environmental Water Use: Shasta River Flow and Temperature Modeling  

E-Print Network (OSTI)

i Improving Managed Environmental Water Use: Shasta River Flow and Temperature Modeling By SARAH and perhaps reduce some water management conflicts. Additional research for managing environmental water use manage water supplies and demands to increase water use efficiency through conservation, water markets

Lund, Jay R.

329

An improved numerical scheme for a coupled system to model soil erosion and polydispersed sediments transport  

E-Print Network (OSTI)

An improved numerical scheme for a coupled system to model soil erosion and polydispersed sediments, the positivity of both water depth and sediment concentrations. Recently, a well-balanced MUSCL-Hancock scheme step is required to ensure the positivity of sediment concentrations. The main result of this paper

Boyer, Edmond

330

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

E-Print Network (OSTI)

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

California at Davis, University of

331

Carbon Nanotube Mats and Fibers with Irradiation-Improved Mechanical Characteristics: ATheoretical Model  

E-Print Network (OSTI)

Carbon Nanotube Mats and Fibers with Irradiation-Improved Mechanical Characteristics: ATheoretical model to calculate mechanical characteristics of macroscopic mats and fibers of single-walled carbon-flow technique [4]. The SWNT fibers, which in contrast to most ordinary carbon fibers could be strongly bent with

Krasheninnikov, Arkady V.

332

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

E-Print Network (OSTI)

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

Kundu, Sukhamay

333

Hands-On and Minds-On Modeling Activities to Improve Students' Conceptions of Microscopic Friction  

E-Print Network (OSTI)

Hands-On and Minds-On Modeling Activities to Improve Students' Conceptions of Microscopic Friction of microscopic friction. We will also present our investigation on the relative effectiveness of the use, it is possible to facilitate the refinement of students' ideas of microscopic friction. Keywords: friction

Zollman, Dean

334

Using radiative transfer models to study the atmospheric water vapor content and to eliminate telluric lines from high-resolution optical spectra  

E-Print Network (OSTI)

The Radiative Transfer Model (RTM) and the retrieval algorithm, incorporated in the SCIATRAN 2.2 software package developed at the Institute of Remote Sensing/Institute of Enviromental Physics of Bremen University (Germany), allows to simulate, among other things, radiance/irradiance spectra in the 2400-24 000 {\\AA} range. In this work we present applications of RTM to two case studies. In the first case the RTM was used to simulate direct solar irradiance spectra, with different water vapor amounts, for the study of the water vapor content in the atmosphere above Sierra Nevada Observatory. Simulated spectra were compared with those measured with a spectrometer operating in the 8000-10 000 {\\AA} range. In the second case the RTM was used to generate telluric model spectra to subtract the atmospheric contribution and correct high-resolution stellar spectra from atmospheric water vapor and oxygen lines. The results of both studies are discussed.

Gardini, A; Prez, E; Quesada, J A; Funke, B

2012-01-01T23:59:59.000Z

335

Improvement plans for the RHIC/AGS on-line model environments  

SciTech Connect

The on-line models for Relativistic Ion Collider (RHIC) and the RHIC pre-injectors (the AGS and the AGS Booster) can be thought of as containing our best collective knowledge of these accelerators. As we improve these on-line models we are building the framework to have a sophisticated model-based controls system. Currently the RHIC on-line model is an integral part of the controls system, providing the interface for tune control, chromaticity control, and non-linear chromaticity control. What we discuss in this paper is our vision of the future of the on-line model environment for RHIC and the RHIC preinjectors. Although these on-line models are primarily used as Courant-Snyder parameter calculators using live machine settings, we envision expanding these environments to encompass many other problem domains.

Brown,K.A.; Ahrens, L.; Beebe-Wang, J.; Morris, J.; Nemesure, S.; Robert-Demolaize, G.; Satogata, T.; Schoefer, V.; Tepikian, S.

2009-08-31T23:59:59.000Z

336

Operator-Split RungeKuttaRosenbrock Methods for Nonhydrostatic Atmospheric Models  

E-Print Network (OSTI)

- trasting this against a vertical discretization with a mini- mum near-surface grid spacing of about 100 m grid spacing leads to a stringent restriction on the time step to maintain numerical stability. Instead by the grid spacing and wave speed in the horizontal. The high-order finite-volume model is tested against

Ullrich, Paul

337

On the Use of an Adaptive, Hybrid-Isentropic Vertical Coordinate in Global Atmospheric Modeling  

Science Journals Connector (OSTI)

This article is one in a series describing the functionality of the Flow-Following, Finite-Volume Icosahedral Model (FIM) developed at NOAAs Earth System Research Laboratory. Emphasis in this article is on the design of the vertical coordinate...

Rainer Bleck; Stan Benjamin; Jin Lee; Alexander E. MacDonald

2010-06-01T23:59:59.000Z

338

Atmospheric and seeing forecast: WRF model validation with in situ measurements at ORM  

Science Journals Connector (OSTI)

......orographic data to initialize WRF. 6 CONCLUSION For the first time, the WRF model, coupled with the...used to forecast not only local meteorological parameters...relative humidity and wind speed at ground level...simultaneous forecasts, the WRF-in situ instrument agreement......

C. Giordano; J. Vernin; H. Vzquez Rami; C. Muoz-Tun; A. M. Varela; H. Trinquet

2013-01-01T23:59:59.000Z

339

Block-structured adaptive meshes and reduced grids for atmospheric general circulation models  

Science Journals Connector (OSTI)

...grids are widely used for local weather predictions and...Research Forecasting Model WRF (Skamarock et al...small time steps if high wind speeds are present in...m and (c) meridional wind v (m1) at day 10 (McDonald...the advanced research WRF Version 2National Center...

2009-01-01T23:59:59.000Z

340

Modeling the downstream improvements in dissolved oxygen from aeration of Cherokee and Douglas releases  

SciTech Connect

This report is an evaluation of downstream improvements in dissolved oxygen (DO) which can be anticipated as a result of different levels of aeration at Cherokee and Douglas Dams. The report describes (a) field studies undertaken to describe late summer conditions for model calibration and verification; (b) development and calibration of unsteady flow and water quality models for the tailwater reaches from Cherokee and Douglas Dams to the Holston and French Broad River confluence at the head of Fort Loudoun Reservoir; and (c) model predictions of DO in the tailwater reaches and at their confluence (after mixing) with and without aeration. 7 refs., 47 figs., 4 tabs.

Hauser, G.E.; Beard, L.M.; Brown, R.T.; McKinnon, M.K.

1983-09-01T23:59:59.000Z

Note: This page contains sample records for the topic "improving atmospheric models" 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.


341

Atmospheric Neutrinos  

E-Print Network (OSTI)

This paper is a brief overview of the theory and experimental data of atmospheric neutrino production at the fiftieth anniversary of the experimental discovery of neutrinos.

Thomas K. Gaisser

2006-12-11T23:59:59.000Z

342

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

SciTech Connect

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

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

2013-08-20T23:59:59.000Z

343

Air-sea interactions during the passage of a winter storm over the Gulf Stream: A three-dimensional coupled atmosphere-ocean model study  

E-Print Network (OSTI)

the surface currents in the Gulf Stream and generate southwestward flows on the shelf. The oceanic feedback% weaker. Differences in the surface ocean currents between these two experiments are significant-dimensional coupled atmosphere-ocean model study Yongping Li1 and Huijie Xue School of Marine Sciences, University

Maine, University of

344

What causes the excessive response of clear-sky greenhouse effect to El Nin~o warming in Community Atmosphere Models?  

E-Print Network (OSTI)

What causes the excessive response of clear-sky greenhouse effect to El Nin~o warming in Community-sky greenhouse effect to El Nin~o warming in the Community Atmosphere Models (CAMs), the response of both water in the lapse rate response to the discrepancies seen in the clear-sky greenhouse effect. The results confirm

Sun, Dezheng

345

Two-moment Bulk Stratiform Cloud Microphysics in the Grid-point Atmospheric Model of IAP LASG (GAMIL)  

SciTech Connect

A two-moment bulk stratiform microphysics scheme, including recently developed physically-based droplet activation/ice nucleation parameterizations has been implemented into the Grid-point Atmospheric Model of IAP LASG (GAMIL) as an effort to enhance the model capability for studying aerosol indirect effects. Unlike the previous one-moment cloud microphysics scheme, the new scheme produces reasonable representation of cloud particle size and number concentration. This scheme captures the observed spatial variations in cloud droplet number concentrations. Simulated ice crystal number concentrations in cirrus clouds qualitatively agree with in-situ observations. The longwave and shortwave cloud forcing are in better agreement with observations. Sensitivity tests show that the column cloud droplet number concentrations calculated from two different droplet activation parameterizations are similar. However, ice crystal number concentration in mixed-phased clouds is sensitive to different heterogeneous freezing formulations. The simulation with high ice crystal number concentration in mixed-phase clouds has less liquid water path and weaker cloud forcing. Furthermore, ice crystal number concentration in cirrus clouds is sensitive to different ice nucleation parameterizations. Sensitivity tests also suggest that impact of pre-existing ice crystals on homogeneous freezing in old clouds should be taken into account.

Shi, Xiangjun; Wang, Bin; Liu, Xiaohong; Wang, Minghuai

2013-05-01T23:59:59.000Z

346

A RECOMMENDED PASQUILL-GIFFORD STABILITY CLASSIFICATION METHOD FOR SAFETY BASIS ATMOSPHERIC DISPERSION MODELING AT SRS  

SciTech Connect

Several of the most common methods for estimating Pasquill-Gifford (PG) stability (turbulence) class were evaluated for use in modeling the radiological consequences of SRS accidental releases using the MELCOR Accident Consequence Code System, Ver. 2 (MACCS2). Evaluation criteria included: (1) the ability of the method to represent diffusion characteristics above a predominantly forested landscape at SRS, (2) suitability of the method to provide data consistent with the formulation of the MACCS2 model, and (3) the availability of onsite meteorological data to support implementation of the method The evaluation resulted in a recommendation that PG stability classification for regulatory applications at SRS should be based on measurements of the standard deviation of the vertical component of wind direction fluctuations, {sigma}{sub e}, collected from the 61-m level of the SRS meteorological towers, and processed in full accordance with EPA-454/R-99-005 (EPA, 2000). This approach provides a direct measurement that is fundamental to diffusion and captures explicitly the turbulence generated by both mechanical and buoyant forces over the characteristic surface (forested) of SRS. Furthermore, due to the potentially significant enhancement of horizontal fluctuations in wind direction from the occurrence of meander at night, the use of {sigma}{sub e} will ensure a reasonably conservative estimate of PG stability class for use in dispersion models that base diffusion calculations on a single value of PG stability class. Furthermore, meteorological data bases used as input for MACCS2 calculations should contain hourly data for five consecutive annual periods from the most recent 10 years.

Hunter, C.

2012-03-28T23:59:59.000Z

347

An Improved Model To Forecast Co2 Leakage Rates Along A Wellbore | Open  

Open Energy Info (EERE)

Model To Forecast Co2 Leakage Rates Along A Wellbore Model To Forecast Co2 Leakage Rates Along A Wellbore Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Journal Article: An Improved Model To Forecast Co2 Leakage Rates Along A Wellbore Details Activities (0) Areas (0) Regions (0) Abstract: Large-scale geological storage of CO2 is likely to bring CO2 plumes into contact with a large number of existing wellbores. Wellbores that no longer provide proper zonal isolation establish a primary pathway for a buoyant CO2-rich phase to escape from the intended storage formation. The hazard of CO2 leakage along these pathways will depend on the rate of leakage. Thus a useful component of a risk assessment framework is a model of CO2 leakage. Predicting the flux of CO2 along a leaking wellbore requires a model of fluid properties and of transport along the leakage

348

Simple solar spectral model for direct and diffuse irradiance on horizontal and tilted planes at the earth's surface for cloudless atmospheres  

SciTech Connect

A new, simple model for calculating clear-sky direct and diffuse spectral irradiance on horizontal and tilted surfaces is presented. The model is based on previously reported simple algorithms and on comparisons with rigorous radiative transfer calculations and limited outdoor measurements. Equations for direct normal irradiance are outlined; and include: Raleigh scattering; aerosol scattering and absorption; water vapor absorption; and ozone and uniformly mixed gas absorption. Inputs to the model include solar zenith angle, collector tilt angle, atmospheric turbidity, amount of ozone and precipitable water vapor, surface pressure, and ground albedo. The model calculates terrestrial spectra from 0.3 to 4.0 ..mu..m with approximately 10 nm resolution. A major goal of this work is to provide researchers with the capability to calculate spectral irradiance for different atmospheric conditions and different collector geometries using microcomputers. A listing of the computer program is provided.

Bird, R.; Riordan, C.

1984-12-01T23:59:59.000Z

349

Developing Model Constraints on Northern Extra-Tropical Carbon Cycling Based on measurements of the Abundance and Isotopic Composition of Atmospheric CO2  

SciTech Connect

The objective of this project was to perform CO2 data syntheses and modeling activities to address two central questions: 1) how much has the seasonal cycle in atmospheric CO2 at northern high latitudes changed since the 1960s, and 2) how well do prognostic biospheric models represent these changes. This project also supported the continuation of the Scripps time series of CO2 isotopes and concentration at ten baseline stations distributed globally.

Keeling, Ralph [UCSD-SIO

2014-12-12T23:59:59.000Z

350

Source Term Estimation of Radioxenon Released from the Fukushima Dai-ichi Nuclear Reactors Using Measured Air Concentrations and Atmospheric Transport Modeling  

SciTech Connect

Systems designed to monitor airborne radionuclides released from underground nuclear explosions detected radioactive fallout from the Fukushima Daiichi nuclear accident in March 2011. Atmospheric transport modeling (ATM) of plumes of noble gases and particulates were performed soon after the accident to determine plausible detection locations of any radioactive releases to the atmosphere. We combine sampling data from multiple International Modeling System (IMS) locations in a new way to estimate the magnitude and time sequence of the releases. Dilution factors from the modeled plume at five different detection locations were combined with 57 atmospheric concentration measurements of 133-Xe taken from March 18 to March 23 to estimate the source term. This approach estimates that 59% of the 1.241019 Bq of 133-Xe present in the reactors at the time of the earthquake was released to the atmosphere over a three day period. Source term estimates from combinations of detection sites have lower spread than estimates based on measurements at single detection sites. Sensitivity cases based on data from four or more detection locations bound the source term between 35% and 255% of available xenon inventory.

Eslinger, Paul W. [Pacific Northwest National Laboratory (PNNL), Richland, WA (United States); Biegalski, S. [Univ. of Texas at Austin, TX (United States); Bowyer, Ted W. [Pacific Northwest National Laboratory (PNNL), Richland, WA (United States); Cooper, Matthew W. [Pacific Northwest National Laboratory (PNNL), Richland, WA (United States); Haas, Derek A. [Pacific Northwest National Laboratory (PNNL), Richland, WA (United States); Hayes, James C. [Pacific Northwest National Laboratory (PNNL), Richland, WA (United States); Hoffman, Ian [Radiation Protection Bureau, Health Canada, Ottawa, ON (Canada); Korpach, E. [Radiation Protection Bureau, Health Canada, Ottawa, ON (Canada); Yi, Jing [Radiation Protection Bureau, Health Canada, Ottawa, ON (Canada); Miley, Harry S. [Pacific Northwest National Laboratory (PNNL), Richland, WA (United States); Rishel, Jeremy P. [Pacific Northwest National Laboratory (PNNL), Richland, WA (United States); Ungar, R. Kurt [Radiation Protection Bureau, Health Canada, Ottawa, ON (Canada); White, Brian [Radiation Protection Bureau, Health Canada, Ottawa, ON (Canada); Woods, Vincent T. [Pacific Northwest National Laboratory (PNNL), Richland, WA (United States)

2014-01-01T23:59:59.000Z

351

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

E-Print Network (OSTI)

gasification, reactions between oxygen and combustibles in the boundary layer, and integration of sulfate reduction and sulfide reoxidation into the char burning process. Simulations using the model show that for typical recovery boiler conditions, char burning...

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

352

Monitoring with the use of passive samplers ?? a useful source of information for the mapping and modelling of urban atmosphere pollution  

Science Journals Connector (OSTI)

Due to human activities, increasing numbers of harmful substances are emitted into the atmosphere; they are recognised as potentially dangerous to living organisms, mainly because of their toxicity. Among others, compounds from the BTEX group, e.g. benzene, toluene, ethylbenzene and xylenes, are considered as such toxic substances. They are present in the air above urbanised as well as rural areas due to their transport in the atmosphere. In order to estimate the human population exposure to the analytes from the BTEX group in the air, it is necessary to monitor the concentration levels of these compounds. The environmental data obtained can be processed further to allow modelling of pollution transport in the atmosphere, and pollution mapping. In this study, literature data on the monitoring of the BTEX concentrations by means of passive dosimetry, and mapping of air pollution from BTEX are presented.

Magdalena Urbanowicz; Bozena Zabiegala; Monika Partyka; Jacek Namiesnik; Cezary Orlowski

2007-01-01T23:59:59.000Z

353

VOCALS: The VAMOS Ocean-Cloud-Atmosphere-Land Study  

DOE Data Explorer (OSTI)

VOCALS (VAMOS* Ocean-Cloud-Atmosphere-Land Study) is an international CLIVAR program the major goal of which is to develop and promote scientific activities leading to improved understanding of the Southeast Pacific (SEP) coupled ocean-atmosphere-land system on diurnal to inter-annual timescales. The principal program objectives are: 1) the improved understanding and regional/global model representation of aerosol indirect effects over the SEP; 2) the elimination of systematic errors in the region of coupled atmospheric-ocean general circulation models, and improved model simulations and predictions of the coupled climate in the SEP and global impacts of the system variability. VOCALS is organized into two tightly coordinated components: 1) a Regional Experiment (VOCALSREx), and 2) a Modeling Program (VOCALS-Mod). Extended observations (e.g. IMET buoy, satellites, EPIC/PACS cruises) will provide important additional contextual datasets that help to link the field and the modeling components. The coordination through VOCALS of observational and modeling efforts (Fig. 3) will accelerate the rate at which field data can be used to improve simulations and predictions of the tropical climate variability [Copied from the Vocals Program Summary of June 2007, available as a link from the VOCALS web at http://www.eol.ucar.edu/projects/vocals/]. The CLIVAR sponsored program to under which VOCALS falls is VAMOS, which stands for Variability of the American Monsoon Systems.

Wood, Robert (VOCALS-REx PI, University of Washington); Bretherton, Christopher (GEWEX/GCSS Representative, University of Washington); Huebert, Barry (SOLAS Representative, University of Hawaii); Mechoso, Roberto C. (VOCALS Science Working Group Chair, UCLA); Weller, Robert (Woods Hole Oceanographic Institution)

354

Improving quality of discriminating signal from background for Higgs portal model  

E-Print Network (OSTI)

In our universe nearly 95 percent of matters are unknown yet, we only have theory, so called Standard Model, for 5 percent of universe. Consequently, our next target of high energy physics is naturally Dark Matter and Dark Energy. In this study we studied Dark matter especially for Higgs portal model. In this study we found discrimination power is improved if we impose MET significance cut instead of MET cut and we don't need to include many variables when we impose MET significance cut.

Kim, Manki

2014-01-01T23:59:59.000Z

355

Improvements of the shock arrival times at the Earth model STOA  

E-Print Network (OSTI)

Prediction of the shocks' arrival times (SATs) at the Earth is very important for space weather forecast. There is a well-known SAT model, STOA, which is widely used in the space weather forecast. However, the shock transit time from STOA model usually has a relative large error compared to the real measurements. In addition, STOA tends to yield too much `yes' prediction, which causes a large number of false alarms. Therefore, in this work, we work on the modification of STOA model. First, we give a new method to calculate the shock transit time by modifying the way to use the solar wind speed in STOA model. Second, we develop new criteria for deciding whether the shock will arrive at the Earth with the help of the sunspot numbers and the angle distances of the flare events. It is shown that our work can improve the SATs prediction significantly, especially the prediction of flare events without shocks arriving at the Earth.

Liu, H -L

2015-01-01T23:59:59.000Z

356

Improved Coefficient Calculator for the California Energy Commission 6 Parameter Photovoltaic Module Model  

SciTech Connect

This paper describes an improved algorithm for calculating the six parameters required by the California Energy Commission (CEC) photovoltaic (PV) Calculator module model. Rebate applications in California require results from the CEC PV model, and thus depend on an up-to-date database of module characteristics. Currently, adding new modules to the database requires calculating operational coefficients using a general purpose equation solver - a cumbersome process for the 300+ modules added on average every month. The combination of empirical regressions and heuristic methods presented herein achieve automated convergence for 99.87% of the 5487 modules in the CEC database and greatly enhance the accuracy and efficiency by which new modules can be characterized and approved for use. The added robustness also permits general purpose use of the CEC/6 parameter module model by modelers and system analysts when standard module specifications are known, even if the module does not exist in a preprocessed database.

Dobos, A. P.

2012-05-01T23:59:59.000Z

357

Model testing using Chernobyl data: III. Atmospheric resuspension of radionuclides in Ukrainian regions impacted by Chernobyl fallout  

SciTech Connect

The {open_quotes}Resuspension{close_quotes} scenario is designed to test models for atmospheric resuspension of radionuclides from contaminated soils. Resuspension can be a secondary source of contamination after a release has stopped, as well as a source of contamination for people and areas not exposed to the original release. The test scenario describes three exposure situations: (1) locations within the highly contaminated 30-km zone at Chernobyl, where exposures to resuspended material are probably dominated by local processes; (2) an urban area (Kiev) outside the 30-km zone, where local processes include extensive vehicular traffic; and (3) a location 40 to 60 km west of the Chernobyl reactor, where upwind sources of contamination are important. Input data include characteristics of the {sup 137}Cs ground contamination around specific sites, climatological data for the sites, characteristics of the terrain and topography, and locations of the sampling sites. Predictions are requested for average air concentrations of {sup 137}Cs at specified locations due to resuspension of Chernobyl fallout and for specified resuspension factors and rates. Test data (field measurements) are available for all endpoints. 9 refs., 4 figs., 11 tabs.

Garger, E.K. [Inst. of Radioecology, Kiev (Ukraine); Hoffman, F.O. [SENES Oak Ridge, Inc., TN (United States); Miller, C.W. [Centers for Disease Control and Prevention, Atlanta, GA (United States)

1996-01-01T23:59:59.000Z

358

Improving the assessment of wave energy resources by means of coupled wave-ocean numerical modeling  

Science Journals Connector (OSTI)

Abstract Sea waves energy represents a renewable and sustainable energy resource, that nevertheless needs to be further investigated to make it more cost-effective and economically appealing. A key step in the process of Wave Energy Converters (WEC) deployment is the energy resource assessment at a sea site either measured or obtained through numerical model analysis. In these kind of studies, some approximations are often introduced, especially in the early stages of the process, viz. waves are assumed propagating in deep waters without underneath ocean currents. These aspects are discussed and evaluated in the Adriatic Sea and its northern part (Gulf of Venice) using locally observed and modeled wave data. In particular, to account for a state of the art treatment of the WaveCurrent Interaction (WCI) we have implemented the Simulating \\{WAves\\} Nearshore (SWAN) model and the Regional Ocean Modeling System (ROMS), fully coupled within the Coupled Ocean Atmosphere Wave Sediment Transport (COAWST) system. COAWST has been applied to a computational grid covering the whole Adriatic Sea and off-line nested to a high-resolution grid in the Gulf of Venice. A 15-year long wave data set collected at the oceanographic tower Acqua Alta, located approximately 15km off the Venice coast, has also been analyzed with the dual purpose of providing a reference to the model estimates and to locally assess the wave energy resource. By using COAWST, we have quantified for the first time to our best knowledge the importance of the WCI effect on wave power estimation. This can vary up to 30% neglecting the current effect. Results also suggest the Gulf of Venice as a suitable testing site for WECs, since it is characterized by periods of calm (optimal for safe installation and maintenance) alternating with severe storms, whose wave energy potentials are comparable to those ordinarily encountered in the energy production sites.

Francesco Barbariol; Alvise Benetazzo; Sandro Carniel; Mauro Sclavo

2013-01-01T23:59:59.000Z

359

Optimization of Switched Reluctance Motor for Efficiency Improvement Using Response Surface Model and Kriging Model  

Science Journals Connector (OSTI)

This paper presented an optimization of switched reluctance motor for higher efficiency. The motor in this study was designed based on the magnetic energy conversion loop according to the power requirements of application system. It's found that besides ... Keywords: switched reluctance motor, optimziation, RSM, Kriging Model

Xueguan Song; Youngchul Park; Jian Li; Joonho Lee

2011-04-01T23:59:59.000Z

360

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

SciTech Connect

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

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

2011-11-23T23:59:59.000Z

Note: This page contains sample records for the topic "improving atmospheric models" 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

Atmospheric tritium  

SciTech Connect

Research progress for the year 1979 to 1980 are reported. Concentrations of tritiated water vapor, tritium gas and tritiated hydrocarbons in the atmosphere at selected sampling points are presented. (ACR)

Oestlund, H.G.; Mason, A.S.

1980-01-01T23:59:59.000Z

362

The Local Structure of Atmospheric Turbulence and Its Effect on the Smagorinsky Model for Large Eddy Simulation  

Science Journals Connector (OSTI)

Phenomena such as large-scale shear, buoyancy, and the proximity to the ground surface significantly affect interactions among scales in atmospheric boundary layer turbulent flows. Hence, these phenomena impact parameters that enter subgrid-scale ...

Marcelo Chamecki; Charles Meneveau; Marc B. Parlange

2007-06-01T23:59:59.000Z

363

Atmospheric three-dimensional inverse modeling of regional industrial emissions and global oceanic uptake of carbon tetrachloride  

E-Print Network (OSTI)

Carbon tetrachloride (CCl4) has substantial stratospheric ozone depletion potential and its consumption is controlled under the Montreal Protocol and its amendments. We implement a Kalman filter using atmospheric CCl4 ...

Xiao, X.

364

Using Multi-scale Dynamic Rupture Models to Improve Ground Motion Estimates  

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

Earthquake simulations help scientists understand the hazards posed by Earthquake simulations help scientists understand the hazards posed by future earthquakes. Earthquake computational models are validated by simulating well-recorded historical earthquakes and comparing simulation results to observational data. The purple border shows the extent of the 3-D structural model in the 3-D inversion. Events in red, with stations in blue. En-Jui Lee, University of Wyoming Using Multi-scale Dynamic Rupture Models to Improve Ground Motion Estimates PI Name: Thomas Jordan PI Email: tjordan@usc.edu Institution: USC Allocation Program: ESP Allocation Hours at ALCF: 150 Million Year: 2010 to 2013 Research Domain: Earth Science Researchers will use Southern California Earthquake Center (SCEC) dynamic rupture simulation software to investigate high-frequency seismic energy

365

Radar range measurements in the atmosphere.  

SciTech Connect

The earth's atmosphere affects the velocity of propagation of microwave signals. This imparts a range error to radar range measurements that assume the typical simplistic model for propagation velocity. This range error is a function of atmospheric constituents, such as water vapor, as well as the geometry of the radar data collection, notably altitude and range. Models are presented for calculating atmospheric effects on radar range measurements, and compared against more elaborate atmospheric models.

Doerry, Armin Walter

2013-02-01T23:59:59.000Z

366

Effects of improved modeling on best estimate BWR severe accident analysis  

SciTech Connect

Since 1981, ORNL has completed best estimate studies analyzing several dominant BWR accident scenarios. These scenarios were identified by early Probabilistic Risk Assessment (PRA) studies and detailed ORNL analysis complements such studies. In performing these studies, ORNL has used the MARCH code extensively. ORNL investigators have identified several deficiencies in early versions of MARCH with regard to BWR modeling. Some of these deficiencies appear to have been remedied by the most recent release of the code. It is the purpose of this paper to identify several of these deficiencies. All the information presented concerns the degraded core thermal/hydraulic analysis associated with each of the ORNL studies. This includes calculations of the containment response. The period of interest is from the time of permanent core uncovery to the end of the transient. Specific objectives include the determination of the extent of core damage and timing of major events (i.e., onset of Zr/H/sub 2/O reaction, initial clad/fuel melting, loss of control blade structure, etc.). As mentioned previously the major analysis tool used thus far was derived from an early version of MARCH. BWRs have unique features which must be modeled for best estimate severe accident analysis. ORNL has developed and incorporated into its version of MARCH several improved models. These include (1) channel boxes and control blades, (2) SRV actuations, (3) vessel water level, (4) multi-node analysis of in-vessel water inventory, (5) comprehensive hydrogen and water properties package, (6) first order correction to the ideal gas law, and (7) separation of fuel and cladding. Ongoing and future modeling efforts are required. These include (1) detailed modeling for the pressure suppression pool, (2) incorporation of B/sub 4/C/steam reaction models, (3) phenomenological model of corium mass transport, and (4) advanced corium/concrete interaction modeling. 10 references, 17 figures, 1 table.

Hyman, C.R.; Ott, L.J.

1984-01-01T23:59:59.000Z

367

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

SciTech Connect

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

Penner, Joyce

2012-06-30T23:59:59.000Z

368

Fiscal year 1998 summary report of the NOAA Atmospheric Sciences Modeling Division to the U.S. Environmental Protection Agency. Technical memo  

SciTech Connect

During Fiscal Year 1998, the Atmospheric Sciences Modeling Division provided meteorological and modeling assistance to the US Environmental Protection Agency. Among the significant research studies and results were the following: publication and distribution of Models-3/Community Mutliscale Air Quality system; estimation of the nitrogen deposition to Chesapeake Bay, continued evaluation and application of air quality models for mercury, dioxin, and heavy metals, continued conduct of deposition velocity field studies over various major categories of land-use; conduct of the Ozark Isoprene Experiment to investigate biogenic isoprene emissions; analysis and modeling of dust resuspension data; continued study of buoyant puff dispersion in the convective boundary layer; and development of a standard practice for an objective statistical procedure for comparing air quality model outputs with field data.

Poole-Kober, E.M.; Viebrock, H.J.

1999-06-01T23:59:59.000Z

369

Designing a model for reliability improvement with FTA and FMEA techniques on medical gas outlet  

Science Journals Connector (OSTI)

In this case study of medical equipment industry, a reliability improvement cycle was conducted about medical gas outlet. Outlet connects four main hospital gases including oxygen, vacuum, air and nitroxide from hospital gas lines to certain equipment such as flowmeter, suction and other medical equipment by adaptor. Outlet product was chosen because it is a necessary and sensitive product in a hospital, and a small mistake during its production and installation can endanger a patient's life. In this study, reliability allocation was initially carried out for outlet parts. Two valves and spring were identified as important parts by means of tools such as functional flow block diagram and N*N that recognised system parts and their relationships. Then, fault tree analysis (FTA), failure modes and effective analysis (FMEA) were performed. System reliability was calculated via Bayesian method. Finally, improvement and redesigning were performed for system. In this study, a new model was proposed for reliability improvement of the products. In addition, reliability of medical gas outlet was increased.

Marzieh Sadeghi; Mehdi Karbasiyan; Mehrzad Navabakhsh

2014-01-01T23:59:59.000Z

370

Improving thermosyphon solar domestic hot water system model performance. Final report, March 1994--February 1995  

SciTech Connect

Data from an indoor solar simulator experimental performance test is used to develop a systematic calibration procedure for a computer model of a thermosyphoning, solar domestic hot water heating system with a tank-in-tank heat exchanger. Calibration is performed using an indoor test with a simulated solar collector to adjust heat transfer in the heat exchanger and heat transfer between adjacent layers of water in the storage tank. An outdoor test is used to calibrate the calculation of the friction drop in the closed collector loop. Additional indoor data with forced flow in the annulus of the heat exchanger leads to improved heat transfer correlations for the inside and outside regions of the tank-in-tank heat exchanger. The calibrated simulation model is compared to several additional outdoor tests both with and without auxiliary heating. Integrated draw energies are predicted with greater accuracy and draw temperature profiles match experimental results to a better degree. Auxiliary energy input predictions improve significantly. 63 figs., 29 tabs.

Swift, T.N.

1996-09-01T23:59:59.000Z

371

Improvement of the equivalent sphere model for better estimates of skin or eye dose in space radiation environments  

E-Print Network (OSTI)

sphere Radiation transport a b s t r a c t It is often useful to get a quick estimate of the dose or dose drastically improves the accuracy of the estimates of dose and dose equivalent in space radiation environmentsImprovement of the equivalent sphere model for better estimates of skin or eye dose in space

Lin, Zi-wei

372

Lifetimes and time scales in atmospheric chemistry  

Science Journals Connector (OSTI)

...such as for years with extensive forest fires. Moving beyond atmospheric chemistry, extension of this approach to Earth system models could yield surprises. The coupling across different components of the chemistry-climate system, such as atmospheric...

2007-01-01T23:59:59.000Z

373

Atmospheric Sciences Program Department of Marine, Earth and Atmospheric Sciences (MEAS)  

E-Print Network (OSTI)

atmospheric chemistry/air quality, boundary layer and air pollution meteorology, regional/global climatology MODELING OF MULTIPLE AIR POLLUTANTS AT URBAN AND REGIONAL SCALES Our atmosphere is a complex systemAtmospheric Sciences Program Department of Marine, Earth and Atmospheric Sciences (MEAS) (http

Parker, Matthew D. Brown

374

Reducing risk in basin scale sequestration: A Bayesian model selection framework for improving detection  

E-Print Network (OSTI)

Geological CO[subscript 2] sequestration is a key technology for mitigating atmospheric greenhouse gas concentrations while providing low carbon energy. Deployment of sequestration at scales necessary for a material ...

Seto, C.J.

375

Borders as membranes :metaphors and models for improved policy in border regions.  

SciTech Connect

Political borders are controversial and contested spaces. In an attempt to better understand movement along and through political borders, this project applied the metaphor of a membrane to look at how people, ideas, and things ''move'' through a border. More specifically, the research team employed this metaphor in a system dynamics framework to construct a computer model to assess legal and illegal migration on the US-Mexico border. Employing a metaphor can be helpful, as it was in this project, to gain different perspectives on a complex system. In addition to the metaphor, the multidisciplinary team utilized an array of methods to gather data including traditional literature searches, an experts workshop, a focus group, interviews, and culling expertise from the individuals on the research team. Results from the qualitative efforts revealed strong social as well as economic drivers that motivate individuals to cross the border legally. Based on the information gathered, the team concluded that legal migration dynamics were of a scope we did not want to consider hence, available demographic models sufficiently capture migration at the local level. Results from both the quantitative and qualitative data searches were used to modify a 1977 border model to demonstrate the dynamic nature of illegal migration. Model runs reveal that current US-policies based on neo-classic economic theory have proven ineffective in curbing illegal migration, and that proposed enforcement policies are also likely to be ineffective. We suggest, based on model results, that improvement in economic conditions within Mexico may have the biggest impact on illegal migration to the U.S. The modeling also supports the views expressed in the current literature suggesting that demographic and economic changes within Mexico are likely to slow illegal migration by 2060 with no special interventions made by either government.

Malczynski, Leonard A.; Passell, Howard David; Forster, Craig B. (University of Utah, Salt Lake City, UT); Cockerill, Kristan (Cockerill Consulting, Boone, NC)

2005-10-01T23:59:59.000Z

376

Evaluation of atmospheric transport models for use in Phase II of the historical public exposures studies at the Rocky Flats Plant  

SciTech Connect

Five atmospheric transport models were evaluated for use in Phase II of the Historical Public Exposures Studies at the Rocky Flats Plant. Models included a simple straight-line Gaussian plume model (ISCST2), several integrated puff models (RATCHET, TRIAD, and INPUFF2), and a complex terrain model (TRAC). Evaluations were based on how well model predictions compared with sulfur hexafluoride tracer measurements taken in the vicinity of Rocky Flats in February 1991. Twelve separate tracer experiments were conducted, each lasting 9 hr and measured at 140 samplers in arcs 8 and 16 km from the release point at Rocky Flats. Four modeling objectives were defined based on the endpoints of the overall study: (1) the unpaired maximum hourly average concentration, (2) paired time-averaged concentration, (3) unpaired time-averaged concentration, and (4) arc-integrated concentration. Performance measures were used to evaluate models and focused on the geometric mean and standard deviation of the predicted-to-observed ratio and the correlation coefficient between predicted and observed concentrations. No one model consistently outperformed the others in all modeling objectives and performance measures. The overall performance of the RATCHET model was somewhat better than the other models.

Rood, A.S.; Killough, G.G.; Till, J.E.

1999-08-01T23:59:59.000Z

377

Feedforward artificial neural network to improve model predictive control in biological processes  

Science Journals Connector (OSTI)

Artificial neural networks (ANNs) offer the versatility of being able to model the dynamics of a biosystem without requiring a phenomenological model. In addition, model predictive control (MPC) is a member of advanced discrete-time process control algorithms. The recent developments in the biotechnology due to MPC utilising the capability of ANN make the practical application of non-linear process control strategies a reality. This paper reviews the recent enhancement and applications of MPC in various biochemical processes using feedforward artificial neural networks which is also known as neural predictive control. The capability of neural predictive control to handle the common problems associated with biochemical processes, namely optimisation of objective function, optimisation of dynamic behaviour of the system, control of ill-defined non-linear systems, improving the computational efficiency of the strategy, disturbance rejection ability and evaluating the control effectiveness are discussed. The review clearly indicates that enormous work has been carried out involving dynamic behaviour of the bioreactor system which is analysed and optimised revealing that feedforward neural network has evolved as a good bioreactor neuro-controller.

Senthil Kumar Arumugasamy; Zainal Ahmad

2011-01-01T23:59:59.000Z

378

Improved Bounds on the Phase Transition for the Hard-Core Model in 2-Dimensions  

E-Print Network (OSTI)

For the hard-core lattice gas model defined on independent sets weighted by an activity $\\lambda$, we study the critical activity $\\lambda_c(\\mathbb{Z}^2)$ for the uniqueness/non-uniqueness threshold on the 2-dimensional integer lattice $\\mathbb{Z}^2$. The conjectured value of the critical activity is approximately $3.796$. Until recently, the best lower bound followed from algorithmic results of Weitz (2006). Weitz presented an FPTAS for approximating the partition function for graphs of constant maximum degree $\\Delta$ when $\\lambda2.388$. In this paper, we establish an upper bound for this approach, by showing that, for all $\\sigma$, SSM does not hold on $T_{\\mathrm{saw}}^\\sigma(\\mathbb{Z}^2)$ when $\\lambda>3.4$. We also present a refinement of the approach of Restrepo et al. which improves the lower bound to $\\lambda_c(\\mathbb{Z}^2)>2.48$.

Juan C. Vera; Eric Vigoda; Linji Yang

2014-07-09T23:59:59.000Z

379

Depositional sequence analysis and sedimentologic modeling for improved prediction of Pennsylvanian reservoirs (Annex 1)  

SciTech Connect

Interdisciplinary studies of the Upper Pennsylvanian Lansing and Kansas City groups have been undertaken in order to improve the geologic characterization of petroleum reservoirs and to develop a quantitative understanding of the processes responsible for formation of associated depositional sequences. To this end, concepts and methods of sequence stratigraphy are being used to define and interpret the three-dimensional depositional framework of the Kansas City Group. The investigation includes characterization of reservoir rocks in oil fields in western Kansas, description of analog equivalents in near-surface and surface sites in southeastern Kansas, and construction of regional structural and stratigraphic framework to link the site specific studies. Geologic inverse and simulation models are being developed to integrate quantitative estimates of controls on sedimentation to produce reconstructions of reservoir-bearing strata in an attempt to enhance our ability to predict reservoir characteristics.

Watney, W.L.

1992-01-01T23:59:59.000Z

380

AN ANALYSIS OF THE PULSATING STAR SDSS J160043.6+074802.9 USING NEW NON-LTE MODEL ATMOSPHERES AND SPECTRA FOR HOT O SUBDWARFS  

SciTech Connect

We first present our new grids of model atmospheres and spectra for hot subdwarf O (sdO) stars: standard non-LTE (NLTE) H+He models with no metals, NLTE line-blanketed models with C+N+O, and NLTE line-blanketed models with C+N+O+Fe. Using hydrogen and helium lines in the optical range, we make detailed comparisons between theoretical spectra of different grids in order to characterize the line-blanketing effects of metals. We find these effects to be dependent on both the effective temperature and the surface gravity. Moreover, we find that the helium abundance also influences in an important way the effects of line blanketing on the resulting spectra. We further find that the addition of Fe (solar abundance) leads only to incremental effects on the atmospheric structure as compared with the case where the metallicity is defined by C+N+O (solar abundances). We use our grids to perform fits on a 9 A resolution, high signal-to-noise ratio ({approx}300 blueward of 5000 A) optical spectrum of SDSS J160043.6+074802.9, the only known pulsating sdO star. Our best and most reliable result is based on the fit achieved with NLTE synthetic spectra that include C, N, O, and Fe in solar abundances, leading to the following parameters: T{sub eff} = 68,500 {+-} 1770 K, log g = 6.09 {+-} 0.07, and log N(He)/N(H) = -0.64 {+-} 0.05 (formal fitting errors only). This combination of parameters, particularly the comparatively high helium abundance, implies that line-blanketing effects due to metals are not very large in the atmosphere of this sdO star.

Latour, M.; Fontaine, G.; Brassard, P. [Departement de Physique, Universite de Montreal, Succ. Centre-Ville, C. P. 6128, Montreal, QC H3C 3J7 (Canada); Green, E. M. [Steward Observatory, University of Arizona, 933 North Cherry Avenue, Tucson, AZ 85721 (United States); Chayer, P. [Space Telescope Science Institute, 3700 San Martin Drive, Baltimore, MD 21218 (United States); Randall, S. K., E-mail: fontaine@astro.umontreal.ca [European Southern Observatory, Karl-Schwarzschild-Str. 2, 85748 Garching (Germany)

2011-06-01T23:59:59.000Z

Note: This page contains sample records for the topic "improving atmospheric models" 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

Transient response of the Hadley Centre coupled ocean-atmosphere model to increasing carbon dioxide. Part I: Control climate and flux adjustment  

SciTech Connect

This paper describes the initialization of an experiment to study the time-dependent response of a high-resolution global coupled ocean-atmosphere general circulation model to a gradual increase in carbon dioxide. The stability of the control integration with respect to climate drift is assessed, and aspects of the model climatology relevant to the simulation of climate change are discussed. The observed variation of oceanic temperature with latitude and depth is basically well simulated, although, in common with other ocean models, the main thermocline is too diffuse. Nevertheless, it is found that large heat and water flux adjustments must be added to the surface layer of the ocean in order to prevent the occurrence of unacceptable climate drift. The ocean model appears to achieve insufficient meridional heat transport, and this is supported by the pattern of the heat flux adjustment term, although errors in the simulated atmosphere-ocean heat flux also contribute to the latter. The application of the flux adjustments restricts climate drift during the 75-year control experiment. However, a gradual warming still occurs in the surface layers of the Southern Ocean because the flux adjustments are inserted as additive terms in this integration and cannot therefore be guaranteed to prevent climate drift completely. 68 refs., 29 figs., 1 tab.

Murphy, J.M. [Hadley Centre for Climate Prediction and Research, Bracknell (United Kingdom)] [Hadley Centre for Climate Prediction and Research, Bracknell (United Kingdom)

1995-01-01T23:59:59.000Z

382

Final Report fir DE-SC0005507 (A1618): The Development of an Improved Cloud Microphysical Product for Model and Remote Sensing Evaluation using RACORO Observations  

SciTech Connect

We proposed to analyze data collected during the Routine Aerial Facilities (AAF) Clouds with Low Optical Water Depths (CLOWD) Optical Radiative Observations (RACORO) in order to develop an integrated product of cloud microphysical properties (number concentration of drops in different size bins, total liquid drop concentration integrated over all bin sizes, liquid water content LWC, extinction of liquid clouds, effective radius of water drops, and radar reflectivity factor) that could be used to evaluate large-eddy simulations (LES), general circulation models (GCMs) and ground-based remote sensing retrievals, and to develop cloud parameterizations with the end goal of improving the modeling of cloud processes and properties and their impact on atmospheric radiation. We have completed the development of this microphysical database. we investigated the differences in the size distributions measured by the Cloud and Aerosol Spectrometer (CAS) and the Forward Scattering Probe (FSSP), between the one dimensional cloud imaging probe (1DC) and the two-dimensional cloud imaging probe (2DC), and between the bulk LWCs measured by the Gerber probe against those derived from the size resolved probes.

McFarquhar, Greg M.

2012-09-21T23:59:59.000Z

383

Evaluation of A New Mixed-Phase Cloud Microphysics Parameterization with the NCAR Climate Atmospheric Model (CAM3) and ARM Observations Fourth Quarter 2007 ARM Metric Report  

SciTech Connect

Mixed-phase clouds are composed of a mixture of cloud droplets and ice crystals. The cloud microphysics in mixed-phase clouds can significantly impact cloud optical depth, cloud radiative forcing, and cloud coverage. However, the treatment of mixed-phase clouds in most current climate models is crude and the partitioning of condensed water into liquid droplets and ice crystals is prescribed as temperature dependent functions. In our previous 2007 ARM metric reports a new mixed-phase cloud microphysics parameterization (for ice nucleation and water vapor deposition) was documented and implemented in the NCAR Community Atmospheric Model Version 3 (CAM3). The new scheme was tested against the Atmospheric Radiation Measurement (ARM) Mixed-phase Arctic Cloud Experiment (M-PACE) observations using the single column modeling and short-range weather forecast approaches. In this report this new parameterization is further tested with CAM3 in its climate simulations. It is shown that the predicted ice water content from CAM3 with the new parameterization is in better agreement with the ARM measurements at the Southern Great Plain (SGP) site for the mixed-phase clouds.

X Liu; SJ Ghan; S Xie; J Boyle; SA Klein

2007-09-30T23:59:59.000Z

384

Nanoparticle Targeting of Anticancer Drug Improves Therapeutic Response in Animal Model of Human Epithelial Cancer  

Science Journals Connector (OSTI)

...Molecular Targets, and Chemical Biology Nanoparticle Targeting of Anticancer Drug Improves...14263. Prior studies suggested that nanoparticle drug delivery might improve the therapeutic...responses not possible with a free drug. Nanoparticle|drug delivery|PAMAM dendrimer...

Jolanta F. Kukowska-Latallo; Kimberly A. Candido; Zhengyi Cao; Shraddha S. Nigavekar; Istvan J. Majoros; Thommey P. Thomas; Lajos P. Balogh; Mohamed K. Khan; James R. Baker, Jr.

2005-06-15T23:59:59.000Z

385

Application of Scale-Selective Data Assimilation to Regional Climate Modeling and Prediction  

Science Journals Connector (OSTI)

A method referred to as scale-selective data assimilation (SSDA) is designed to inject the large-scale components of the atmospheric circulation from a global model into a regional model to improve regional climate simulations and predictions. ...

Shiqiu Peng; Lian Xie; Bin Liu; Fredrick Semazzi

2010-04-01T23:59:59.000Z

386

Ecosystem feedbacks to climate change in California: Development, testing, and analysis using a coupled regional atmosphere and land-surface model (WRF3-CLM3.5)  

SciTech Connect

A regional atmosphere model [Weather Research and Forecasting model version 3 (WRF3)] and a land surface model [Community Land Model, version 3.5 (CLM3.5)] were coupled to study the interactions between the atmosphere and possible future California land-cover changes. The impact was evaluated on California's climate of changes in natural vegetation under climate change and of intentional afforestation. The ability of WRF3 to simulate California's climate was assessed by comparing simulations by WRF3-CLM3.5 and WRF3-Noah to observations from 1982 to 1991. Using WRF3-CLM3.5, the authors performed six 13-yr experiments using historical and future large-scale climate boundary conditions from the Geophysical Fluid Dynamics Laboratory Climate Model version 2.1 (GFDL CM2.1). The land-cover scenarios included historical and future natural vegetation from the Mapped Atmosphere-Plant-Soil System-Century 1 (MC1) dynamic vegetation model, in addition to a future 8-million-ha California afforestation scenario. Natural vegetation changes alone caused summer daily-mean 2-m air temperature changes of -0.7 to +1 C in regions without persistent snow cover, depending on the location and the type of vegetation change. Vegetation temperature changes were much larger than the 2-m air temperature changes because of the finescale spatial heterogeneity of the imposed vegetation change. Up to 30% of the magnitude of the summer daily-mean 2-m air temperature increase and 70% of the magnitude of the 1600 local time (LT) vegetation temperature increase projected under future climate change were attributable to the climate-driven shift in land cover. The authors projected that afforestation could cause local 0.2-1.2 C reductions in summer daily-mean 2-m air temperature and 2.0-3.7 C reductions in 1600 LT vegetation temperature for snow-free regions, primarily because of increased evapotranspiration. Because some of these temperature changes are of comparable magnitude to those projected under climate change this century, projections of climate and vegetation change in this region need to consider these climate-vegetation interactions.

Subin, Z.M.; Riley, W.J.; Kueppers, L.M.; Jin, J.; Christianson, D.S.; Torn, M.S.

2010-11-01T23:59:59.000Z

387

E-Print Network 3.0 - atmospheric diffusion experiments Sample...  

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

technical coupling software... linking the main model components of present-day Earth System models (ESMs), i.e. the atmosphere... be followed to couple ocean and atmosphere...

388

E-Print Network 3.0 - atmospheric experiment recherche Sample...  

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

technical coupling software... linking the main model components of present-day Earth System models (ESMs), i.e. the atmosphere... be followed to couple ocean and atmosphere...

389

E-Print Network 3.0 - atmospheric interference Sample Search...  

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

technical coupling software... linking the main model components of present-day Earth System models (ESMs), i.e. the atmosphere... be followed to couple ocean and atmosphere...

390

FEM3C, An improved three-dimensional heavy-gas dispersion model: User`s manual  

SciTech Connect

FEM3C is another upgraded version of FEM3 (a three-dimensional Finite Element Model), which was developed primarily for simulating the atmospheric dispersion of heavier-than-air gas (or heavy gas) releases, based on solving the fully three-dimensional, time-dependent conservation equations of mass, momentum, energy, and species of an inert gas or a pollutant in the form of vapor/droplets. A generalized anelastic approximation, together with the ideal gas law for the density of the gas/air mixture, is invoked to preclude sound waves and allow large density variations in both space and time. Thee numerical algorithm utilizes a modified Galerkin finite element method to discretize spatially the time-dependent conservation equations of mass, momentum, energy, and species. A consistent pressure Poisson equation is formed and solved separately from the time-dependent equations, which are sequentially solved and integrated in time via a modified forward Euler method. The model can handle instantaneous source, finite-duration, and continuous releases. Also, it is capable of treating terrain and obstructions. Besides a K-theory model using similarity functions, an advanced turbulence model based on solving the k - {var_epsilon} transport equations is available as well. Imbedded in the code are also options for solving the Boussinesq equations. In this report, an overview of the model is given, user`s guides for using the model are provided, and example problems are presented to illustrate the usage of the model.

Chan, S.T.

1994-03-01T23:59:59.000Z

391

Final report for grant DE-FG02-06ER64182: "Evaluation and Improvement of the Cloud Resolving Model Component of the Multi-Scale Modeling Framework"  

SciTech Connect

The overall aim of the larger collaborative effort of which this project was part was to evaluate and improve the cloud system resolving model (CSRM) at the heart of the multi-scale modeling framework (MMF). Our task at the University of Colorado our effort was to develop methods that would let us evaluate the performance of cloud-scale models at the ARM SGP site using ARM remote sensing products.

Pincus, Robert [University of Colorado] [University of Colorado

2009-10-13T23:59:59.000Z

392

Improvement of the Post-Blowdown Fuel Channel Analysis Model of Candu for a 35% RIH Break LOCA Without ECC  

SciTech Connect

A CATHENA model for a post-blowdown fuel channel analysis has been improved from an existing one for a Candu-6 reactor, and the analysis for a RIH 35% LBLOCA/LOECC has been performed. The results for the blowdown and post blowdown analyses show that the post blowdown model and its connection with the blowdown analysis model is successfully implemented. Also the 3-D CFD model for the fluid flow and heat transfer in the Candu fuel channel, is being developed for the post blowdown fuel channel heatup experiment CS28-1 using CFX 5.6 and its recent progress is described. (authors)

Rhee, B. W.; Kang, H.S.; Min, B.J. [Korea Atomic Energy Research Institute, P.O. Box 105, Yuseong, Daejeon, 305-600 (Korea, Republic of)

2004-07-01T23:59:59.000Z

393

Evaluation of Preindustrial to Present-day Black Carbon and its Albedo Forcing from Atmospheric Chemistry and Climate Model Intercomparison Project (ACCMIP)  

SciTech Connect

As a part of the Atmospheric Chemistry and Climate Model Intercomparison Project (ACCMIP), we evaluate the historical black carbon (BC) aerosols simulated by 8 ACCMIP models against the observations including 12 ice core records, a long-term surface mass concentrations and recent Arctic BC snowpack measurements. We also estimate BC albedo forcing by performing additional simulations using the NCAR Community Land and Sea-Ice model 4 with prescribed meteorology from 1996-2000, which includes the SNICAR BC-snow model. We evaluated the vertical profile of BC snow concentrations from these offline simulations to using recent BC snowpack measurements. Despite using the same BC emissions, global BC burden differs by approximately a factor of 3 among models due to the differences in aerosol removal parameterizations and simulated meteorology among models; 34 Gg to 103 Gg in 1850 and 82 Gg to 315 Gg in 2000. However,models agree well on 2.5~3 times increase in the global BC burden from preindustrial to present-day, which matches with the 2.5 times increase in BC emissions. We find a large model diversity at both NH and SH high latitude regions for BC burden and at SH high latitude regions for deposition fluxes. The ACCMIP simulations match the observed BC mass concentrations well in Europe and North America except at Jungfrauch and Ispra. However, the models fail to capture the Arctic BC seasonality due tosevere underestimations during winter and spring. Compared to recent snowpack measurements, the simulated vertically resolved BC snow concentrations are, on average, within a factor of 2-3 of observations except for Greenland and Arctic Ocean. However, model and observation differ widely due to missing interannual variations in emissions and possibly due to the choice of the prescribed meteorology period (i.e., 1996-2000).

Lee, Y. H.; Lamarque, J.-F.; Flanner, M. G.; Jiao, C.; Shindell, Drew; Berntsen, T.; Bisiauxs, M.; Cao, J.; Collins, W. J.; Curran, M.; Edwards, R.; Faluvegi, G.; Ghan, Steven J.; Horowitz, L.; McConnell, J.R.; Ming, J.; Myhre, G.; Nagashima, T.; Naik, Vaishali; Rumbold, S.; Skeie, R. B.; Sudo, K.; Takemura, T.; Thevenon, F.; Xu, B.; Yoon, Jin-Ho

2013-03-05T23:59:59.000Z

394

SciTech Connect: Using a Simple Binomial Model to Assess Improvement...  

Office of Scientific and Technical Information (OSTI)

Assess Improvement in Predictive Capability: Sequential Bayesian Inference, Hypothesis Testing, and Power Analysis Citation Details In-Document Search Title: Using a Simple...

395

An Improved Adaptive Exponential Smoothing Model for Short-term Travel Time Forecasting of Urban Arterial Street  

Science Journals Connector (OSTI)

Short-term forecasting of travel time is essential for the success of intelligent transportation system. In this paper, we review the state-of-art of short-term traffic forecasting models and outline their basic ideas, related works, advantages and disadvantages of each model. An improved adaptive exponential smoothing (IAES) model is also proposed to overcome the drawbacks of the previous adaptive exponential smoothing model. Then, comparing experiments are carried out under normal traffic condition and abnormal traffic condition to evaluate the performance of four main branches of forecasting models on direct travel time data obtained by license plate matching (LPM). The results of experiments show each model seems to have its own strength and weakness. The forecasting performance of IASE is superior to other models in shorter forecasting horizon (one and two step forecasting) and the IASE is capable of dealing with all kind of traffic conditions.

Zhi-Peng LI; Hong YU; Yun-Cai LIU; Fu-Qiang LIU

2008-01-01T23:59:59.000Z

396

Florian SEITZ: Atmospheric and oceanic impacts to Earth rotations numerical studies with a dynamic Earth system model  

E-Print Network (OSTI)

with a dynamic Earth system model (completed in October 2004) Variations of Earth rotation are caused Earth system model DyMEG has been developed. It is based on the balance of angular momentum

Schuh, Harald

397

Impact of horizontal resolution on simulation of precipitation extremes in an aqua-planet version of the Community Atmosphere Model (CAM)  

SciTech Connect

One key question regarding current climate models is whether the projection of climate extremes converges to a realistic representation as the spatial and temporal resolutions of the model are increased. Ideally the model extreme statistics should approach a fixed distribution once the resolutions are commensurate with the characteristic length and time scales of the processes governing the formation of the extreme phenomena of interest. In this study, a series of AGCM runs with idealized 'aquaplanet-steady-state' boundary conditions have been performed with the Community Atmosphere Model CAM3 to investigate the effect of horizontal resolution on climate extreme simulations. The use of the aquaplanet framework highlights the roles of model physics and dynamics and removes any apparent convergence in extreme statistics due to better resolution of surface boundary conditions and other external inputs. Assessed at a same large spatial scale, the results show that the horizontal resolution and time step have strong effects on the simulations of precipitation extremes. The horizontal resolution has a much stronger impact on precipitation extremes than on mean precipitation. Updrafts are strongly correlated with extreme precipitation at tropics at all the resolutions, while positive low-tropospheric temperature anomalies are associated with extreme precipitation at mid-latitudes.

Li, F.; Collins, W.D.; Wehner, M.F.; Williamson, D.L.; Olson, J.G.; Algieri, C.

2011-03-01T23:59:59.000Z

398

Composition and Reactions of Atmospheric Aerosol Particles  

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

Composition and Reactions of Composition and Reactions of Atmospheric Aerosol Particles Composition and Reactions of Atmospheric Aerosol Particles Print Wednesday, 29 June 2005 00:00 Microscopic aerosol particles in the atmosphere contain carbonaceous components from mineral dust and combustion emissions released from around the world. How long these tiny particles remain in the atmosphere can have a huge impact on the global climate. Measurements based on high-resolution scanning transmission x-ray images obtained at the ALS have revealed chemical reactions on and in atmospheric aerosol particles that caused particle growth while changing organic composition by 13 to 24% per day, an oxidation rate significantly slower than is currently used in atmospheric models. Since oxidation has a strong effect on particle lifetime in the atmosphere, these results will help climate scientists refine the computer models used to predict climate change.

399

Composition and Reactions of Atmospheric Aerosol Particles  

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

Composition and Reactions of Atmospheric Aerosol Particles Print Composition and Reactions of Atmospheric Aerosol Particles Print Microscopic aerosol particles in the atmosphere contain carbonaceous components from mineral dust and combustion emissions released from around the world. How long these tiny particles remain in the atmosphere can have a huge impact on the global climate. Measurements based on high-resolution scanning transmission x-ray images obtained at the ALS have revealed chemical reactions on and in atmospheric aerosol particles that caused particle growth while changing organic composition by 13 to 24% per day, an oxidation rate significantly slower than is currently used in atmospheric models. Since oxidation has a strong effect on particle lifetime in the atmosphere, these results will help climate scientists refine the computer models used to predict climate change.

400

Composition and Reactions of Atmospheric Aerosol Particles  

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

Composition and Reactions of Atmospheric Aerosol Particles Print Composition and Reactions of Atmospheric Aerosol Particles Print Microscopic aerosol particles in the atmosphere contain carbonaceous components from mineral dust and combustion emissions released from around the world. How long these tiny particles remain in the atmosphere can have a huge impact on the global climate. Measurements based on high-resolution scanning transmission x-ray images obtained at the ALS have revealed chemical reactions on and in atmospheric aerosol particles that caused particle growth while changing organic composition by 13 to 24% per day, an oxidation rate significantly slower than is currently used in atmospheric models. Since oxidation has a strong effect on particle lifetime in the atmosphere, these results will help climate scientists refine the computer models used to predict climate change.

Note: This page contains sample records for the topic "improving atmospheric models" 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

One-Dimensional Modeling on the Asymmetric Features of a Radio-Frequency Atmospheric Helium Glow Discharge Produced Using a Co-Axial-Type Plasma Generator  

Science Journals Connector (OSTI)

As one type of the atmospheric glow discharges, the radio-frequency atmospheric-pressure glow discharges produced using the water-cooled bare-metallic electrode, which are the...13...]. The capacitively-coupled ...

Zhi-Bin Wang; Pei-Si Le; Nan Ge; Qiu-Yue Nie

2012-08-01T23:59:59.000Z

402

Effect of a non-thermal, atmospheric-pressure, plasma brush on conversion of model self-etch adhesive formulations compared to conventional photo-polymerization  

Science Journals Connector (OSTI)

Objective To determine the effectiveness and efficiency of non-thermal, atmospheric plasmas for inducing polymerization of model dental self-etch adhesives. Methods The monomer mixtures used were bis-[2-(methacryloyloxy)ethyl] phosphate (2MP) and 2-hydroxyethyl methacrylate (HEMA), with mass ratios of 70/30, 50/50 and 30/70. Water was added to the above formulations: 1030wt%. These monomer/water mixtures were treated steadily for 40s under a non-thermal atmospheric plasma brush working at temperatures from 32 to 35C. For comparison, photo-initiators were added to the above formulations for photo-polymerization studies, which were light-cured for 40s. The degree of conversion (DC) of both the plasma- and light-cured samples was measured using FTIR spectroscopy with an attenuated total reflectance attachment. Results The non-thermal plasma brush was effective in inducing polymerization of the model self-etch adhesives. The presence of water did not negatively affect the DC of plasma-cured samples. Indeed, DC values slightly increased, with increasing water content in adhesives: from 58.3% to 68.7% when the water content increased from 10% to 30% in the adhesives with a 50/50 (2MP/HEMA) mass ratio. Conversion values of the plasma-cured groups were higher than those of light-cured samples with the same mass ratio and water content. Spectral differences between the plasma- and light-cured groups indicate subtle structural distinctions in the resultant polymer networks. Significance This research if the first to demonstrate that the non-thermal plasma brush induces polymerization of model adhesives under clinical settings by direct/indirect energy transfer. This device shows promise for polymerization of dental composite restorations having enhanced properties and performance.

Mingsheng Chen; Ying Zhang; Xiaomei Yao; Hao Li; Qingsong Yu; Yong Wang

2012-01-01T23:59:59.000Z

403

The identification of HCN and HNC in Carbon Stars: Model Atmospheres, Synthetic Spectra and Fits to Observations in the 2.7-4.0 micron Region  

E-Print Network (OSTI)

Model carbon star atmospheres and synthetic spectra have been calculated using the recent HCN/HNC vibration rotation linelist of Harris et al. (2002) ApJ, 578, 657. The calculations are repeated using only HCN lines and show that HNC has a significant effect upon the temperature, density and optical depth of a stellar atmosphere. We fit synthetic spectra in the 2.7-4.0 micron region to observed ISO spectra of the carbon stars WZ Cas and TX Psc obtained by Aoki et al. (1998), A&A, 340, 222. These fits allow us to identify absorption by HNC in the spectrum of WZ Cas at 2.8-2.9 microns, and to determine new independent estimates of effective temperature and log(Nc)/log(No). The findings reported here indicate that absorption by both HCN and HNC is needed to fully explain the observed stellar spectra and represent the first identification of HNC in a star. Q branch absorption by the HCN $\\Delta v_2=1$, $\\Delta v_3=1$ and $\\Delta v_1=1$, $\\Delta v_2=-1$ bands at 3.55 and 3.86 microns respectively, are identified in the spectrum of WZ Cas.

G. J. Harris; Ya. V. Pavlenko; H. R. A. Jones; J. Tennyson

2003-06-06T23:59:59.000Z

404

Transient response of the Hadley Centre coupled ocean-atmosphere model to increasing carbon dioxide. Part II: Spatial and temporal structure of response  

SciTech Connect

A high-resolution (2.75{degrees} lat x 3.75{degrees} long) coupled ocean-atmosphere model has been used to simulate the transient response of climate to a gradual increase in atmospheric carbon dioxide concentrations. Although the radiative forcing increases linearly, there is a delay of about 30 yr before the ocean warms appreciably. This {open_quotes}cold start{close_quotes} is, at least partly, an artifact of the experimental design. At the time of doubling (after 70 yr), the patterns of change are similar to those found in comparable studies of the equilibrium response, except in the high latitudes of the Southern Ocean and the North Atlantic, where the warming is considerably reduced. The mechanisms leading to this reduction are discussed. After two to three decades, the pattern of warming is well established. The warming over land is substantially larger than that over the sea, with a consequent lowering of surface pressure over the northern continents in summer. The patterns of changes in precipitation and soil moisture take longer to establish themselves, although locally there are consistent changes after the third decade. 55 refs., 30 figs., 6 tabs.

Murphy, J.M.; Mitchell, J.F.B. [Hadley Centre for Climate Prediction and Research, Berkshire (United Kingdom)] [Hadley Centre for Climate Prediction and Research, Berkshire (United Kingdom)

1995-01-01T23:59:59.000Z

405

MeTAGeM-Trace: Improving trace generation in model transformation by leveraging the role of transformation models  

Science Journals Connector (OSTI)

Abstract In the context of Model-Driven Engineering (MDE), generation of traces can be automated using the implicit traceability relationships contained in any model transformation. Besides, if transformations are developed adopting a Model-Driven Engineering (MDE) approach, i.e. promoting the role of models and the level of automation, model transformation will benefit from the promised advantages of MDE in terms of less costly software development while reducing the inherent complexity of coding model transformations. To put these ideas into practice, this work introduces MeTAGeM-Trace, the first prototype of an EMF-based toolkit for the MDD of model-to-model transformations which supports trace generation, i.e. it allows developing model transformations that produce not only the corresponding target models, but also a trace model between the elements of the source and target models involved in the transformation.

lvaro Jimnez; Juan M. Vara; Vernica A. Bollati; Esperanza Marcos

2015-01-01T23:59:59.000Z

406

Response of global soil consumption of atmospheric methane to changes in atmospheric climate and nitrogen deposition  

E-Print Network (OSTI)

Response of global soil consumption of atmospheric methane to changes in atmospheric climate June 2013. [1] Soil consumption of atmospheric methane plays an important secondary role in regulating). Here we used a process-based biogeochemistry model to quantify soil consumption during the 20th and 21

407

Northerly surface wind events over the eastern North Pacific Ocean : spatial distribution, seasonality, atmospheric circulation, and forcing  

E-Print Network (OSTI)

ECMWF and NCEP numerical weather prediction models, Mon.atmospheric numerical weather prediction model. The

Taylor, Stephen V.

2006-01-01T23:59:59.000Z

408

Atmospheric chemistry impacts and feedbacks on the global carbon cycle  

E-Print Network (OSTI)

prediction. Issues to be addressed include the quantification of the impact of the atmospheric oxidation and the oxidative state of the atmosphere. The end goal is to create a model that can quantitatively predict is required to: Predict 3-D atmospheric CO2 production as a function of the CCSM3 atmospheric chemistry module

409

The Energy Spectrum of Atmospheric Neutrinos between 2 and 200 TeV with the AMANDA-II Detector  

SciTech Connect

The muon and anti-muon neutrino energy spectrum is determined from 2000-2003 AMANDA telescope data using regularised unfolding. This is the first measurement of atmospheric neutrinos in the energy range 2-200 TeV. The result is compared to different atmospheric neutrino models and it is compatible with the atmospheric neutrinos from pion and kaon decays. No significant contribution from charm hadron decays or extraterrestrial neutrinos is detected. The capabilities to improve the measurement of the neutrino spectrum with the successor experiment IceCube are discussed.

IceCube Collaboration; Abbasi, R.

2010-05-11T23:59:59.000Z

410

Section 6. Deep Time: Modelling of Atmospheric CO2 and the Marine CO2-Carbonic Acid-Carbonate System  

Science Journals Connector (OSTI)

...original MAGic model (Arvidson et al., 2006) as revised in Arvidson et al. (2011). There are a number of Earth system models in the literature (e.g., Berner and Canfield 1989; Hansen and Wallmann, 2003; Berner 2004; Bergman et al...

Fred T. Mackenzie; Andreas J. Andersson

411

Atmosphere-Surface Exchange Measurements  

Science Journals Connector (OSTI)

...HICKS, B.B., A SIMULATION OF THE EDDY ACCUMULATION...CLOSURES IN 2ND-ORDER MODELING, JOURNAL OF THE ATMOSPHERIC...Their advantag-es are rapid response, linear output...the measurement and modeling of surface fluxes are...the appli-cation of automated conditional sampling...

W. F. Dabberdt; D. H. Lenschow; T. W. Horst; P. R. Zimmerman; S. P. Oncley; A. C. Delany

1993-06-04T23:59:59.000Z

412

Toward Improved Identifiability of Soil Hydraulic Parameters: On the Selection of a Suitable Parametric Model  

E-Print Network (OSTI)

Parametric Model Jasper A. Vrugt,* Willem Bouten, Hoshin V. Gupta, and Jan W. Hopmans ABSTRACT Richards

Vrugt, Jasper A.

413

Computational Model of Forward and Opposed Smoldering Combustion with Improved Chemical Kinetics (PhD. Thesis)  

E-Print Network (OSTI)

for modeling urethane foam insulation performance, Journalinsulation, upholstery, shock absorbing, and soundproofing. PU foam

Rein, Guillermo

2005-01-01T23:59:59.000Z

414

Response of a coupled ocean-ice-atmosphere model to data assimilation in the tropical zone of the Pacific Ocean  

Science Journals Connector (OSTI)

This paper deals with numerical experiments based on the coupled ECHAM-HOPE model. The results of experiments are analyzed. The initial fields for the calculations over time periods from one month to one year ...

K. P. Belyaev; N. P. Tuchkova; U. Cubash

2010-06-01T23:59:59.000Z

415

A process for evaluation and state approval of an emergency response atmospheric dispersion model for Rocky Flats, Colorado  

SciTech Connect

This document contains copies of the vugraphs used by C. R. Hodgin for the November 6, 1991 presentation summarizing the process to be used for evaluation of the Emergency Response Dispersion Model. (MHB)

Hodgin, C.R.

1991-11-06T23:59:59.000Z

416

Sensitivity of tropical deep convection in global models: effects of horizontal resolution, surface constraints and 3D atmospheric nudging  

E-Print Network (OSTI)

, the Eastern Indian Ocean and Maritime Continent, and 174 tropical South America. The Inter Tropical Convergence Zone (ITCZ), and to a smaller extent the 175 South Pacific Convergence Zone (SPCZ), also have their signatures in the OLR and PR fields. When 176... larger for PR. This is 161 in agreement with previous studies, which show large model precipitation biases in tropical ocean 162 regions (Martin et al., 2010; Schiemann et al., 2014). For OLR ~85% of model configurations are in 163 good agreement...

Chemel, Charles; Russo, Maria; Hosking, Scott; Telford, Paul; Pyle, John

2014-01-01T23:59:59.000Z

417

Posters Scanning Raman Lidar Measurements of Atmospheric Water Vapor and Aerosols  

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

5 5 Posters Scanning Raman Lidar Measurements of Atmospheric Water Vapor and Aerosols R. A. Ferrare and K. D. Evans (a) Hughes STX Corporation Lanham, Maryland S. H. Melfi and D. N. Whiteman NASA/Goddard Space Flight Center Greenbelt, Maryland The principal objective of the Department of Energy's (DOE) Atmospheric Radiation Measurement Program (ARM) is to develop a better understanding of the atmospheric radiative balance in order to improve the parameterization of radiative processes in general circulation models (GCMs) which are used to study climate change. Meeting this objective requires detailed measurements of both water vapor and aerosols since these atmospheric constituents affect the radiation balance directly, through scattering and absorption of solar and

418

Trees and beyond : exploiting and improving tree-structured graphical models  

E-Print Network (OSTI)

Probabilistic models commonly assume that variables are independent of each other conditioned on a subset of other variables. Graphical models provide a powerful framework for encoding such conditional independence structure ...

Choi, Myung Jin, Ph. D. Massachusetts Institute of Technology

2011-01-01T23:59:59.000Z

419

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

Energy.gov (U.S. Department of Energy (DOE))

Discusses progress on thermal comfort modeling and detailed design, fabrication, and component/system-level testing of TE architecture

420

Consequence analysis of aqueous ammonia spills using an improved liquid pool evaporation model  

E-Print Network (OSTI)

of Acrolein released into air.................................................................98 x LIST OF TABLES Page Table 1. Assumptions for modeling scenarios...

Raghunathan, Vijay

2005-02-17T23:59:59.000Z

Note: This page contains sample records for the topic "improving atmospheric models" 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

Improving the predictive power of spatial statistical models of stream macroinvertebrates using weighted autocovariance functions  

Science Journals Connector (OSTI)

Spatial statistical stream-network models are useful for modelling physicochemical data, but to-date have not been fit to macroinvertebrate data. Spatial stream-network models were fit to three macroinvertebrate indices: percent pollution-tolerant taxa, ... Keywords: Aquatic monitoring, Macroinvertebrate index, Scale, Spatial autocorrelation, Spatial statistics

Jennifer C. Frieden, Erin E. Peterson, J. Angus Webb, Peter M. Negus

2014-10-01T23:59:59.000Z

422

Using Direct Sub-Level Entity Access to Improve Nuclear Stockpile Simulation Modeling  

SciTech Connect

Direct sub-level entity access is a seldom-used technique in discrete-event simulation modeling that addresses the accessibility of sub-level entity information. The technique has significant advantages over more common, alternative modeling methods--especially where hierarchical entity structures are modeled. As such, direct sub-level entity access is often preferable in modeling nuclear stockpile, life-extension issues, an area to which it has not been previously applied. Current nuclear stockpile, life-extension models were demonstrated to benefit greatly from the advantages of direct sub-level entity access. In specific cases, the application of the technique resulted in models that were up to 10 times faster than functionally equivalent models where alternative techniques were applied. Furthermore, specific implementations of direct sub-level entity access were observed to be more flexible, efficient, functional, and scalable than corresponding implementations using common modeling techniques. Common modeling techniques (''unbatch/batch'' and ''attribute-copying'') proved inefficient and cumbersome in handling many nuclear stockpile modeling complexities, including multiple weapon sites, true defect analysis, and large numbers of weapon and subsystem types. While significant effort was required to enable direct sub-level entity access in the nuclear stockpile simulation models, the enhancements were worth the effort--resulting in more efficient, more capable, and more informative models that effectively addressed the complexities of the nuclear stockpile.

Robert Y. Parker

1999-08-01T23:59:59.000Z

423

The role of neuro-fuzzy modelling as a greening technique, in improving the performance of vehicular spark ignition engine  

Science Journals Connector (OSTI)

The spark ignition engine, by far, is the largest source of motive power in the world. Therefore, continuous endeavours to improve its performance are needed to save in fuel consumption and reduce cost. The main goal of this paper is to develop a neuro-fuzzy model for fuel Injection Time (IT) in order to design a neuro-fuzzy controller for improving the performance of the spark ignition engine. The obtained results showed that the developed neuro-fuzzy model is capable of predicting the fuel IT with a mean squared error less than 0.0072. Furthermore, the power produced by the neuro-fuzzy controller has higher values of about 15-73% than the power produced by the PID controller used in the basic engine. The BSFC is reduced by about 2-5% compared to the PID controller.

Mashhour M. Bani Amer; Yousef S.H. Najjar

2010-01-01T23:59:59.000Z

424

Using suite energy-use and interior condition data to improve energy modeling of a 1960s MURB  

Science Journals Connector (OSTI)

Abstract Energy modeling is a useful tool for evaluating the performance of contemplated building energy retrofit measures. Traditionally, energy models are developed using data collected from building floor plans and site visits and are then calibrated using utility bills. In the work presented here, an energy model for an existing multi-unit residential building (MURB) was developed using this traditional approach. Next, a refined approach was taken. Using data gathered from a suite-based monitoring program, input data uncertainties in the energy model were addressed. Data from one year of monitoring were assembled to characterize the actual building performance and to calibrate this refined energy model. In order to identify which parameters could be used to improve the model accuracy, the output of this refined model was compared to the output from the traditional modeling approach. It was found that the interior temperature measurements and the sub-metered suite electricity use were the most beneficial in refining the energy model. However, other data collected including window operation and differential air pressures were useful for determining how the building was operating. The use of a local weather file generated from a roof-top weather station has also been discussed.

Marianne F. Touchie; Kim D. Pressnail

2014-01-01T23:59:59.000Z

425

Modeling of the Cryogenic Liquid Pool Evaporation and the Effect of the Convective Heat Transfer from Atmosphere  

E-Print Network (OSTI)

of this activity. This includes the prediction of the consequences of potential loss of containment of LNG, which requires the modelling of the vaporization rate of LNG resulting from the heat transfer between the pool and surroundings. The present work focuses...

Nawaz, Waqas

2014-04-25T23:59:59.000Z

426

Modeling the barotropic response of the global ocean to atmospheric wind and pressure forcing -comparisons with observations  

E-Print Network (OSTI)

-G. Model outputs are compared to in situ observations with tide gauge data (TG) and bottom pressure gauge data (BPR), and also with T/P altimetric cross over points (noted CO). Intercomparisons were performed/P and Jason altimeters deliver very accurate data sets (within 2 centimeter global error for T/P). How- ever

427

Improving Efficiencyof SymbolicModelCheckingfor State-Based System Requirements  

E-Print Network (OSTI)

that the techniques together reduce the time and space complexities by orders of magnitude; these improvements have and space complexities by orders of magni- tude, making feasible some analysisthat was previously intractable. The TCAS II requirements were writtenin RSML, a dialectof state- charts. Keywords Formal

Beame, Paul

428

Carbon nanotube mats and fibers with irradiation-improved mechanical characteristics: a theoretical model  

E-Print Network (OSTI)

1 Carbon nanotube mats and fibers with irradiation-improved mechanical characteristics characteristics of macroscopic mats and fibers of single-walled carbon nanotubes. We further investigate]. The SWNT fibers, which in contrast to most ordinary carbon fibers could be strongly bent without breaking

Nordlund, Kai

429

A Comprehensive Parameterization of Heterogeneous Ice Nucleation of Dust Surrogate: Laboratory Study with Hematite Particles and Its Application to Atmospheric Models  

SciTech Connect

A new heterogeneous ice nucleation parameterization that covers a wide temperature range (-36 ?C to -78 ?C) is presented. Developing and testing such an ice nucleation parameterization, which is constrained through identical experimental conditions, is critical in order to accurately simulate the ice nucleation processes in cirrus clouds. The surface-scaled ice nucleation efficiencies of hematite particles, inferred by ns, were derived from AIDA (Aerosol Interaction and Dynamics in the Atmosphere) cloud chamber measurements under water subsaturated conditions that were realized by continuously changing temperature (T) and relative humidity with respect to ice (RHice) in the chamber. Our measurements showed several different pathways to nucleate ice depending on T and RHice conditions. For instance, almost independent freezing was observed at -60 ?C < T < -50 ?C, where RHice explicitly controlled ice nucleation efficiency, while both T and RHice played roles in other two T regimes: -78 ?C < T < -60 ?C and -50 ?C < T < -36 ?C. More specifically, observations at T colder than -60 ?C revealed that higher RHice was necessary to maintain constant ns, whereas T may have played a significant role in ice nucleation at T warmer than -50 ?C. We implemented new ns parameterizations into two cloud models to investigate its sensitivity and compare with the existing ice nucleation schemes towards simulating cirrus cloud properties. Our results show that the new AIDA-based parameterizations lead to an order of magnitude higher ice crystal concentrations and inhibition of homogeneous nucleation in colder temperature regions. Our cloud simulation results suggest that atmospheric dust particles that form ice nuclei at lower temperatures, below -36 ?C, can potentially have stronger influence on cloud properties such as cloud longevity and initiation when compared to previous parameterizations.

Hiranuma, Naruki; Paukert, Marco; Steinke, Isabelle; Zhang, Kai; Kulkarni, Gourihar R.; Hoose, Corinna; Schnaiter, Martin; Saathoff, Harald; Mohler, Ottmar

2014-12-10T23:59:59.000Z

430

Integrating Empirical-Modeling Approaches to Improve Understanding of Terrestrial Ecology Processes  

SciTech Connect

Recent decades have seen tremendous increases in the quantity of empirical ecological data collected by individual investigators, as well as through research networks such as FLUXNET (Baldocchi et al., 2001). At the same time, advances in computer technology have facilitated the development and implementation of large and complex land surface and ecological process models. Separately, each of these information streams provides useful, but imperfect information about ecosystems. To develop the best scientific understanding of ecological processes, and most accurately predict how ecosystems may cope with global change, integration of empirical and modeling approaches is necessary. However, true integration - in which models inform empirical research, which in turn informs models (Fig. 1) - is not yet common in ecological research (Luo et al., 2011). The goal of this workshop, sponsored by the Department of Energy, Office of Science, Biological and Environmental Research (BER) program, was to bring together members of the empirical and modeling communities to exchange ideas and discuss scientific practices for increasing empirical - model integration, and to explore infrastructure and/or virtual network needs for institutionalizing empirical - model integration (Yiqi Luo, University of Oklahoma, Norman, OK, USA). The workshop included presentations and small group discussions that covered topics ranging from model-assisted experimental design to data driven modeling (e.g. benchmarking and data assimilation) to infrastructure needs for empirical - model integration. Ultimately, three central questions emerged. How can models be used to inform experiments and observations? How can experimental and observational results be used to inform models? What are effective strategies to promote empirical - model integration?

McCarthy, Heather [University of Oklahoma; Luo, Yiqi [University of Oklahoma; Wullschleger, Stan D [ORNL

2012-01-01T23:59:59.000Z

431

Atmospheric radiation measurement program facilities newsletter, June 2002.  

SciTech Connect

ARM Intensive Operational Period Scheduled to Validate New NASA Satellite--Beginning in July, all three ARM sites (Southern Great Plains [SGP], North Slope of Alaska, and Tropical Western Pacific; Figure 1) will participate in the AIRS Validation IOP. This three-month intensive operational period (IOP) will validate data collected by the satellite-based Atmospheric Infrared Sounder (AIRS) recently launched into space. On May 4, the National Aeronautics and Space Administration (NASA) launched Aqua, the second spacecraft in the Earth Observing System (EOS) series. The EOS satellites monitor Earth systems including land surfaces, oceans, the atmosphere, and ice cover. The first EOS satellite, named Terra, was launched in December 1999. The second EOS satellite is named Aqua because its primary focus is understanding Earth's water cycle through observation of atmospheric moisture, clouds, temperature, ocean surface, precipitation, and soil moisture. One of the instruments aboard Aqua is the AIRS, built by the Jet Propulsion Laboratory, a NASA agency. The AIRS Validation IOP complements the ARM mission to improve understanding of the interactions of clouds and atmospheric moisture with solar radiation and their influence on weather and climate. In support of satellite validation IOP, ARM will launch dedicated radiosondes at all three ARM sites while the Aqua satellite with the AIRS instrument is orbiting overhead. These radiosonde launches will occur 45 minutes and 5 minutes before selected satellite overpasses. In addition, visiting scientists from the Jet Propulsion Laboratory will launch special radiosondes to measure ozone and humidity over the SGP site. All launches will generate ground-truth data to validate satellite data collected simultaneously. Data gathered daily by ARM meteorological and solar radiation instruments will complete the validation data sets. Data from Aqua-based instruments, including AIRS, will aid in weather forecasting, climate modeling, and greenhouse gas studies. These instruments will provide more accurate, detailed global observations of weather and atmospheric parameters that will, in turn, improve the accuracy and quality of weather forecasts. A satellite-based instrument is cost-effective because it can provide continuous global measurements, eliminating isolated yet costly weather balloon releases. Aqua, launched from Vandenberg Air Force Base in California (Figure 2), carries six state-of-the-art instruments that measure various water vapor parameters: (1) AIRS, which measures atmospheric temperature and humidity, land and sea surface temperatures, cloud properties, and radiative energy flux; (2) Advanced Microwave Sounding Unit, which measures atmospheric temperature and humidity during both cloudy and cloud-free periods; (3) Advanced Microwave Scanning Radiometer, which measures cloud properties, radiative energy flux, precipitation rates, land surface wetness, sea ice, snow cover, sea surface temperature, and wind fields; (4) Clouds and the Earth's Radiant Energy System, which measures radiative energy flux; (5) Humidity Sounder for Brazil, which measures atmospheric humidity by using a passive scanning microwave radiometer; and (6) Moderate Resolution Imaging Spectroradiometer, which measures cloud properties, radiative energy flux, aerosol properties, land cover and land use change, vegetation dynamics, land surface temperature, fire occurrence, volcanic effects, sea surface temperature, ocean color, snow cover, atmospheric temperature and humidity, and sea ice. The data-gathering capabilities of the Aqua instruments will provide an unprecedented view of atmosphere-land interactions (Figure 3). The availability of more frequent, more accurate global measurements of important atmospheric parameters will both improve our capabilities for short-term weather forecasting and lead to a better understanding of climate variability and climate change. Simultaneous measurements of many parameters will allow scientists to study complicated forcings and feedbacks of the atmosphere, which can be

Holdridge, D. J.

2002-07-03T23:59:59.000Z

432

Integrated reservoir characterization: Improvement in heterogeneities stochastic modelling by integration of additional external constraints  

SciTech Connect

The classical approach to construct reservoir models is to start with a fine scale geological model which is informed with petrophysical properties. Then scaling-up techniques allow to obtain a reservoir model which is compatible with the fluid flow simulators. Geostatistical modelling techniques are widely used to build the geological models before scaling-up. These methods provide equiprobable images of the area under investigation, which honor the well data, and which variability is the same than the variability computed from the data. At an appraisal phase, when few data are available, or when the wells are insufficient to describe all the heterogeneities and the behavior of the field, additional constraints are needed to obtain a more realistic geological model. For example, seismic data or stratigraphic models can provide average reservoir information with an excellent areal coverage, but with a poor vertical resolution. New advances in modelisation techniques allow now to integrate this type of additional external information in order to constrain the simulations. In particular, 2D or 3D seismic derived information grids, or sand-shale ratios maps coming from stratigraphic models can be used as external drifts to compute the geological image of the reservoir at the fine scale. Examples are presented to illustrate the use of these new tools, their impact on the final reservoir model, and their sensitivity to some key parameters.

Doligez, B.; Eschard, R. [Institut Francais du Petrole, Rueil Malmaison (France); Geffroy, F. [Centre de Geostatistique, Fontainebleau (France)] [and others

1997-08-01T23:59:59.000Z

433

Improving Rainfall Processes in Climate Models | U.S. DOE Office...  

Office of Science (SC) Website

have completed SCM simulations of seven GCMs participating in the "FASTER" project led by Brookhaven National Laboratory and compared the models' performance to 3 years of...

434

Improving baseline forecasts in a 500-industry dynamic CGE model of the USA.  

E-Print Network (OSTI)

??MONASH-style CGE models have been used to generate baseline forecasts illustrating how an economy is likely to evolve through time. One application of such forecasts (more)

Mavromatis, Peter George

2013-01-01T23:59:59.000Z

435

Atmospheric histories and growth trends Diane J. Ivy, Tim Arnold, Christina M. Harth, L. Paul Steele, Jens Mhle,  

E-Print Network (OSTI)

Atmospheric histories and growth trends of C4 F10 , C5 F12 , C6 F14 , C7 F16 and C8 F18 * Diane J to: discover new interactions among natural and human climate system components; objectively assess future; and improve methods to model, monitor and verify greenhouse gas emissions and climatic impacts

436

On testing the significance of atmospheric response to smoke from the Kuwaiti oil fires using the Los Alamos general circulation model  

SciTech Connect

The response of the Los Alamos atmospheric general circulation model to the smoke from the Kuwaiti oil fires set in 1991 is examined. The model has an interactive soot transport module that uses a Lagrangian tracer particle scheme. The statistical significance of the results is evaluated using a methodology based on the classic Student`s t test. Among various estimated smoke emission rates and associated visible absorption coefficients, the worst- and best-case scenarios are selected. In each of the scenarios, an ensemble of 10, 30-day June simulations are conducted with the smoke, and are compared to the same 10 June simulations without the smoke. The results of the worst-case scenario show that a statistically significant wave train pattern propagates eastward-poleward downstream from the source. The signals favorably compare with the observed climate anomalies in summer 1991, albeit some possible El Nino-Southern Oscillation effects were involved in the actual climate. The results of the best-case (i.e., least-impact) scenario show that the significance is rather small but that its general pattern is quite similar to that in the worst-case scenario. 24 refs., 5 figs.

Chih-Yue Jim Kao; Glatzmaier, G.A.; Malone, R.C. [Los Alamos National Lab., NM (United States)

1994-07-20T23:59:59.000Z

437

Development of Improved Models and Designs for Coated-Particle Gas Reactor Fuels (I-NERI Annual Report)  

SciTech Connect

The objective of this INERI project is to develop improved fuel behavior models for gas reactor coated particle fuels and to develop improved coated-particle fuel designs that can be used reliably at very high burnups and potentially in fast gas-cooled reactors. Thermomechanical, thermophysical, and physiochemical material properties data were compiled by both the US and the French and preliminary assessments conducted. Comparison between U.S. and European data revealed many similarities and a few important differences. In all cases, the data needed for accurate fuel performance modeling of coated particle fuel at high burnup were lacking. The development of the INEEL fuel performance model, PARFUME, continued from earlier efforts. The statistical model being used to simulate the detailed finite element calculations is being upgraded and improved to allow for changes in fuel design attributes (e.g. thickness of layers, dimensions of kernel) as well as changes in important material properties to increase the flexibility of the code. In addition, modeling of other potentially important failure modes such as debonding and asphericity was started. A paper on the status of the model was presented at the HTR-2002 meeting in Petten, Netherlands in April 2002, and a paper on the statistical method was submitted to the Journal of Nuclear Material in September 2002. Benchmarking of the model against Japanese and an older DRAGON irradiation are planned. Preliminary calculations of the stresses in a coated particle have been calculated by the CEA using the ATLAS finite element model. This model and the material properties and constitutive relationships will be incorporated into a more general software platform termed Pleiades. Pleiades will be able to analyze different fuel forms at different scales (from particle to fuel body) and also handle the statistical variability in coated particle fuel. Diffusion couple experiments to study Ag and Pd transport through SiC were conducted. Analysis and characterization of the samples continues. Two active transport mechanisms are proposed: diffusion in SiC and release through SiC cracks or another, as yet undetermined, path. Silver concentration profiles determined by XPS analysis suggest diffusion within the SiC layer, most likely dominated by grain boundary diffusion. However, diffusion coefficients calculated from mass loss measurements suggest a much faster release path, postulated as small cracks or flaws that provide open paths with little resistance to silver migration. Work is ongoing to identify and characterize this path. Work on Pd behavior has begun and will continue next year.

Petti, David Andrew; Maki, John Thomas; Languille, Alain; Martin, Philippe; Ballinger, Ronald

2002-11-01T23:59:59.000Z

438

Coupling of ecological and water quality models for improved water resource and fish management  

E-Print Network (OSTI)

values of primary producers and other groups to predict fish biomass. Linking the two models will provide the means of going up the food chain by trophic levels. The Chesapeake Bay was chosen as the study site since both models are in use there. Before...

Tillman, Dorothy Hamlin

2009-05-15T23:59:59.000Z

439

Improving the Performance of Mass-Consistent Numerical Models Using Optimization Techniques  

Science Journals Connector (OSTI)

This paper describes a technique of using a mass-consistent model to derive wind speeds over a microscale region (about 4 km2) of complex terrain. A serious limitation of these numerical models is that the calculated wind field is highly ...

J. C. Barnard; H. L. Wegley; T. R. Hiester

1987-06-01T23:59:59.000Z

440

Development and Testing of a Life Cycle Model and a Parameterization of Thin Mid-level Stratiform Clouds  

SciTech Connect

We used a cloud-resolving model (a detailed computer model of cloud systems) to evaluate and improve the representation of clouds in global atmospheric models used for numerical weather prediction and climate modeling. We also used observations of the atmospheric state, including clouds, made at DOE's Atmospheric Radiation Measurement (ARM) Program's Climate Research Facility located in the Southern Great Plains (Kansas and Oklahoma) during Intensive Observation Periods to evaluate our detailed computer model as well as a single-column version of a global atmospheric model used for numerical weather prediction (the Global Forecast System of the NOAA National Centers for Environmental Prediction). This so-called Single-Column Modeling approach has proved to be a very effective method for testing the representation of clouds in global atmospheric models. The method relies on detailed observations of the atmospheric state, including clouds, in an atmospheric column comparable in size to a grid column used in a global atmospheric model. The required observations are made by a combination of in situ and remote sensing instruments. One of the greatest problems facing mankind at the present is climate change. Part of the problem is our limited ability to predict the regional patterns of climate change. In order to increase this ability, uncertainties in climate models must be reduced. One of the greatest of these uncertainties is the representation of clouds and cloud processes. This project, and ARM taken as a whole, has helped to improve the representation of clouds in global atmospheric models.

Krueger, Steven K.

2008-03-03T23:59:59.000Z

Note: This page contains sample records for the topic "improving atmospheric models" 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

Improvements in fast-response flood modeling: desktop parallel computing and domain tracking  

SciTech Connect

It is becoming increasingly important to have the ability to accurately forecast flooding, as flooding accounts for the most losses due to natural disasters in the world and the United States. Flood inundation modeling has been dominated by one-dimensional approaches. These models are computationally efficient and are considered by many engineers to produce reasonably accurate water surface profiles. However, because the profiles estimated in these models must be superimposed on digital elevation data to create a two-dimensional map, the result may be sensitive to the ability of the elevation data to capture relevant features (e.g. dikes/levees, roads, walls, etc...). Moreover, one-dimensional models do not explicitly represent the complex flow processes present in floodplains and urban environments and because two-dimensional models based on the shallow water equations have significantly greater ability to determine flow velocity and direction, the National Research Council (NRC) has recommended that two-dimensional models be used over one-dimensional models for flood inundation studies. This paper has shown that two-dimensional flood modeling computational time can be greatly reduced through the use of Java multithreading on multi-core computers which effectively provides a means for parallel computing on a desktop computer. In addition, this paper has shown that when desktop parallel computing is coupled with a domain tracking algorithm, significant computation time can be eliminated when computations are completed only on inundated cells. The drastic reduction in computational time shown here enhances the ability of two-dimensional flood inundation models to be used as a near-real time flood forecasting tool, engineering, design tool, or planning tool. Perhaps even of greater significance, the reduction in computation time makes the incorporation of risk and uncertainty/ensemble forecasting more feasible for flood inundation modeling (NRC 2000; Sayers et al. 2000).

Judi, David R [Los Alamos National Laboratory; Mcpherson, Timothy N [Los Alamos National Laboratory; Burian, Steven J [UNIV. OF UTAH

2009-01-01T23:59:59.000Z

442

CRAC2 model description  

SciTech Connect

The CRAC2 computer code is a revised version of CRAC (Calculation of Reactor Accident Consequences) which was developed for the Reactor Safety Study. This document provides an overview of the CRAC2 code and a description of each of the models used. Significant improvements incorporated into CRAC2 include an improved weather sequence sampling technique, a new evacuation model, and new output capabilities. In addition, refinements have been made to the atmospheric transport and deposition model. Details of the modeling differences between CRAC2 and CRAC are emphasized in the model descriptions.

Ritchie, L.T.; Alpert, D.J.; Burke, R.P.; Johnson, J.D.; Ostmeyer, R.M.; Aldrich, D.C.; Blond, R.M.

1984-03-01T23:59:59.000Z

443

Simulation of Atmospheric Pressure Non-Thermal Plasma Discharges for Surface Decontamination Applications  

Science Journals Connector (OSTI)

Numerical simulations are conducted to characterize atmospheric pressure plasma discharges for surface decontamination applications. A self ... dimensional hybrid model is developed to simulate the atmospheric pr...

T. Farouk; B. Farouk; A. Gutsol; A. Fridman

2008-01-01T23:59:59.000Z

444

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

Office of Energy Efficiency and Renewable Energy (EERE)

Autonomie, an advanced vehicle modeling and design software package created by Argonne National laboratory with EERE support, is helping U.S. auto manufacturers develop the next generation of hybrid and electric vehicles.

445

The Application of Improved Grey GM(1,1) Model in Power System Load Forecast  

Science Journals Connector (OSTI)

According to existing Grey prediction model GM (1,1) in the data fluctuation, mutation, turning under uncertainty such as the problem of poor prediction accuracy, this paper presents an original data sequence ...

Zhengyuan Jia; Zhou Fan; Chuancai Li

2012-01-01T23:59:59.000Z

446

Private Company Uses EERE-Supported Chemistry Model to Substantially Improve Combustion Engine Simulation Software  

Energy.gov (U.S. Department of Energy (DOE))

Convergent Science, Inc. (CSI) is using Lawrence Livermore National Laboratorys Multi-Zone Combustion Model (MCM) to help automotive engineers develop the next generation of high-efficiency, low-emission vehicles.

447

Hadley Cell Dynamics in a Virtually Dry Snowball Earth Atmosphere  

Science Journals Connector (OSTI)

The Hadley cell of a virtually dry snowball Earth atmosphere under equinox insolation is studied in a comprehensive atmospheric general circulation model. In contrast to the Hadley cell of modern Earth, momentum transport by dry convection, which ...

Aiko Voigt; Isaac M. Held; Jochem Marotzke

2012-01-01T23:59:59.000Z

448

Improved test statistics for the slope parameter in a simple linear functional model  

E-Print Network (OSTI)

of the Studentized test statistic based on the NL estimator of ()1, 1. 2 Survey of the literature A wide variety of sources exists from which to extract useful information for attacking the problem of testing hypotheses in the errors-in-variables model. Se... via simulation that these test statistics perform poorly in moderate to small sample sizes. 1. 3 Pzamewozk of Expositions This thesis is organized as follows. Chapter 2 presents a simple linear functional model, formulates the problem...

Ollivier, Vincent Raymond

2012-06-07T23:59:59.000Z

449

Atmospheric Radiation Measurement Climate Research Facility (ACRF) Annual Report 2008  

SciTech Connect

The Importance of Clouds and Radiation for Climate Change: The Earths surface temperature is determined by the balance between incoming solar radiation and thermal (or infrared) radiation emitted by the Earth back to space. Changes in atmospheric composition, including greenhouse gases, clouds, and aerosols, can alter this balance and produce significant climate change. Global climate models (GCMs) are the primary tool for quantifying future climate change; however, there remain significant uncertainties in the GCM treatment of clouds, aerosol, and their effects on the Earths energy balance. In 1989, the U.S. Department of Energy (DOE) Office of Science created the Atmospheric Radiation Measurement (ARM) Program to address scientific uncertainties related to global climate change, with a specific focus on the crucial role of clouds and their influence on the transfer of radiation in the atmosphere. To reduce these scientific uncertainties, the ARM Program uses a unique twopronged approach: The ARM Climate Research Facility, a scientific user facility for obtaining long-term measurements of radiative fluxes, cloud and aerosol properties, and related atmospheric characteristics in diverse climate regimes; and The ARM Science Program, focused on the analysis of ACRF and other data to address climate science issues associated with clouds, aerosols, and radiation, and to improve GCMs. This report provides an overview of each of these components and a sample of achievements for each in fiscal year (FY) 2008.

LR Roeder

2008-12-01T23:59:59.000Z

450

An economic decision framework using modeling for improving aquifer remediation design  

SciTech Connect

Reducing cost is a critical challenge facing environmental remediation today. One of the most effective ways of reducing costs is to improve decision-making. This can range from choosing more cost- effective remediation alternatives (for example, determining whether a groundwater contamination plume should be remediated or not) to improving data collection (for example, determining when data collection should stoop). Uncertainty in site conditions presents a major challenge for effective decision-making. We present a framework for increasing the effectiveness of remedial design decision-making at groundwater contamination sites where there is uncertainty in many parameters that affect remediation design. The objective is to provide an easy-to-use economic framework for making remediation decisions. The presented framework is used to 1) select the best remedial design from a suite of possible ones, 2) estimate if additional data collection is cost-effective, and 3) determine the most important parameters to be sampled. The framework is developed by combining elements from Latin-Hypercube simulation of contaminant transport, economic risk-cost-benefit analysis, and Regional Sensitivity Analysis (RSA).

James, B.R.; Gwo, J.P.; Toran, L.E.

1995-11-01T23:59:59.000Z

451

Some challenges of middle atmosphere data assimilation  

E-Print Network (OSTI)

Some challenges of middle atmosphere data assimilation 1234567 89A64BC7DEF72B4 8629EEC7C72DEEE5.1256/qj.05.87 Some challenges of middle atmosphere data assimilation By S. POLAVARAPU1,2, T. G. SHEPHERD2 Data assimilation is employed at operational weather forecast centres to combine measurements and model

Wirosoetisno, Djoko

452

Modeling Improvements for Air Source Heat Pumps using Different Expansion Devices at Varied Charge Levels Part II  

SciTech Connect

This paper describes steady-state performance simulations performed on a 3-ton R-22 split heat pump in heating mode. In total, 150 steady-state points were simulated, which covers refrigerant charge levels from 70 % to 130% relative to the nominal value, the outdoor temperatures at 17 F (-8.3 C), 35 F (1.7 C) and 47 F (8.3 C), indoor air flow rates from 60% to 150% of the rated air flow rate, and two types of expansion devices (fixed orifice and thermostatic expansion valve). A charge tuning method, which is to calibrate the charge inventory model based on measurements at two operation conditions, was applied and shown to improve the system simulation accuracy significantly in an extensive range of charge levels. In addition, we discuss the effects of suction line accumulator in modeling a heat pump system using either a fixed orifice or thermal expansion valve. Last, we identify the issue of refrigerant mass flow mal-distribution at low charge levels and propose an improved modeling approach.

Shen, Bo [ORNL

2011-01-01T23:59:59.000Z

453

Time dependences of atmospheric Carbon dioxide fluxes  

E-Print Network (OSTI)

Understanding the lifetime of CO2 in the atmosphere is critical for predictions regarding future climate changes. A simple mass conservation analysis presented here generates tight estimations for the atmosphere's retention time constant. The analysis uses a leaky integrator model that combines the observed deficit (only less than 40% of CO2 produced from combustion of fossil fuels is actually retained in the atmosphere, while more than 60% is continuously shed) with the exponential growth of fossil fuel burning. It reveals a maximum characteristic time of less than 23 year for the transfer of atmospheric CO2 to a segregation sink. This time constant is further constrained by the rapid disappearance of 14C after the ban of atmospheric atomic bomb tests, which provides a lower limit of 18 years for this transfer. The study also generates evaluations of other CO2 fluxes, exchange time constants and volumes exchanged. Analysis of large harmonic oscillations of atmospheric CO2 concentration, often neglected in th...

DeSalvo, Riccardo

2014-01-01T23:59:59.000Z

454

Low energy WSN data aggregation algorithm based on improved aggregation tree model  

Science Journals Connector (OSTI)

To keep the data synchronisation and fidelity of each node in wireless sensor network (WSN), we propose a router-combined data fusion algorithm based on broadcast tree. The approximation algorithm is used to transform the optimum aggregation tree into NP-C problem to solve the smallest Steiner tree. Then the cluster-based optimising directed diffusion routing is adopted to construct aggregation tree for data fusion. At the fusion phase, we introduce consensus factor to support degree matrix, to replace original constant factor and provide more weight effect for reliable sensor. The improved support degree matrix will measure the support degree of each sensor to form a novel weighted fusion algorithm. The analyses on simulation show that our fusion algorithm can make data fusion effectively, which also has higher performance in delay, energy and accuracy.

Pinghui Zou; Yun Liu

2014-01-01T23:59:59.000Z

455

Improved Modeling and Understanding of Diffusion-Media Wettability on Polymer-Electrolyte-Fuel-Cell Performance  

SciTech Connect

A macroscopic-modeling methodology to account for the chemical and structural properties of fuel-cell diffusion media is developed. A previous model is updated to include for the first time the use of experimentally measured capillary pressure -- saturation relationships through the introduction of a Gaussian contact-angle distribution into the property equations. The updated model is used to simulate various limiting-case scenarios of water and gas transport in fuel-cell diffusion media. Analysis of these results demonstrate that interfacial conditions are more important than bulk transport in these layers, where the associated mass-transfer resistance is the result of higher capillary pressures at the boundaries and the steepness of the capillary pressure -- saturation relationship. The model is also used to examine the impact of a microporous layer, showing that it dominates the response of the overall diffusion medium. In addition, its primary mass-transfer-related effect is suggested to be limiting the water-injection sites into the more porous gas-diffusion layer.

Weber, Adam

2010-03-05T23:59:59.000Z

456

Improving reviews of conceptual models by extended traceability to captured system usage  

Science Journals Connector (OSTI)

......extended traceability to captured system usage P. Haumer a * M. Jarke a c K. Pohl b...elicited by analysing concrete system-usage scenarios [Pohl, K., Weidenhaupt...understand the basis (concrete system usage) on which the conceptual models were built......

P. Haumer; M. Jarke; K. Pohl; K. Weidenhaupt

2000-09-01T23:59:59.000Z

457

Improving Accuracy in Ultra-Wideband Indoor Position Tracking through Noise Modeling and  

E-Print Network (OSTI)

. In this work we develop a noise model for this sensor set noise, along with a particle filter that uses our set like to thank God for guiding the path to my degree by pro- viding me with wonderful parents, a great

Hoover, Adam

458

On an improved sub-regional water resources management representation for integration into earth system models  

SciTech Connect

Human influence on the hydrologic cycle includes regulation and storage, consumptive use and overall redistribution of water resources in space and time. Representing these processes is essential for applications of earth system models in hydrologic and climate predictions, as well as impact studies at regional to global scales. Emerging large-scale research reservoir models use generic operating rules that are flexible for coupling with earth system models. Those generic operating rules have been successful in reproducing the overall regulated flow at large basin scales. This study investigates the uncertainties of the reservoir models from different implementations of the generic operating rules using the complex multi-objective Columbia River Regulation System in northwestern United States as an example to understand their effects on not only regulated flow but also reservoir storage and fraction of the demand that is met. Numerical experiments are designed to test new generic operating rules that combine storage and releases targets for multi-purpose reservoirs and to compare the use of reservoir usage priorities, withdrawals vs. consumptive demand, as well as natural vs. regulated mean flow for calibrating operating rules. Overall the best performing implementation is the use of the combined priorities (flood control storage targets and irrigation release targets) operating rules calibrated with mean annual natural flow and mean monthly withdrawals. The challenge of not accounting for groundwater withdrawals, or on the contrary, assuming that all remaining demand is met through groundwater extractions, is discussed.

Voisin, Nathalie; Li, Hongyi; Ward, Duane L.; Huang, Maoyi; Wigmosta, Mark S.; Leung, Lai-Yung R.

2013-09-30T23:59:59.000Z

459

A Global Climatology of Albedo, Roughness Length and Stomatal Resistance for Atmospheric General Circulation Models as Represented by the Simple Biosphere Model (SiB)  

Science Journals Connector (OSTI)

Components of the Simple Biosphere Model (SiB) of Sellers et al. were used to generate global monthly fields of surface albedo (0.44.0 ?m), roughness length and minimum surface (stomatal) resistance.

J. L. Dorman; P. J. Sellers

1989-09-01T23:59:59.000Z

460

Atmospheric Transport of Radionuclides  

SciTech Connect

The purpose of atmospheric transport and diffusion calculations is to provide estimates of concentration and surface deposition from routine and accidental releases of pollutants to the atmosphere. This paper discusses this topic.

Crawford, T.V.

2003-03-03T23:59:59.000Z

Note: This page contains sample records for the topic "improving atmospheric models" 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

The Boulder Atmospheric Observatory  

Science Journals Connector (OSTI)

The Boulder Atmospheric Observatory (BAO) is a unique research facility for studying the planetary boundary layer and for testing and calibrating atmospheric sensors. The facility includes a 300 m tower instrumented with fast- and slow-response ...

J. C. Kaimal; J. E. Gaynor

1983-05-01T23:59:59.000Z

462

Improved one day-ahead price forecasting using combined time series and artificial neural network models for the electricity market  

Science Journals Connector (OSTI)

The price forecasts embody crucial information for generators when planning bidding strategies to maximise profits. Therefore, generation companies need accurate price forecasting tools. Comparison of neural network and auto regressive integrated moving average (ARIMA) models to forecast commodity prices in previous researches showed that the artificial neural network (ANN) forecasts were considerably more accurate than traditional ARIMA models. This paper provides an accurate and efficient tool for short-term price forecasting based on the combination of ANN and ARIMA. Firstly, input variables for ANN are determined by time series analysis. This model relates the current prices to the values of past prices. Secondly, ANN is used for one day-ahead price forecasting. A three-layered feed-forward neural network algorithm is used for forecasting next-day electricity prices. The ANN model is then trained and tested using data from electricity market of Iran. According to previous studies, in the case of neural networks and ARIMA models, historical demand data do not significantly improve predictions. The results show that the combined ANN??ARIMA forecasts prices with high accuracy for short-term periods. Also, it is shown that policy-making strategies would be enhanced due to increased precision and reliability.

Ali Azadeh; Seyed Farid Ghaderi; Behnaz Pourvalikhan Nokhandan; Shima Nassiri

2011-01-01T23:59:59.000Z

463

Representing El Nio in Coupled OceanAtmosphere GCMs: The Dominant Role of the Atmospheric Component  

Science Journals Connector (OSTI)

A systematic modular approach to investigate the respective roles of the ocean and atmosphere in setting El Nio characteristics in coupled general circulation models is presented. Several state-of-the-art coupled models sharing either the same ...

E. Guilyardi; S. Gualdi; J. Slingo; A. Navarra; P. Delecluse; J. Cole; G. Madec; M. Roberts; M. Latif; L. Terray

2004-12-01T23:59:59.000Z

464

8, 10691088, 2008 Atmospheric  

E-Print Network (OSTI)

into the atmosphere (Molina et al., 1974; Farman et al., 1985) has led to an interna- tional effort to replace

Boyer, Edmond

465

An improved analytical model for shear modulus of fiber reinforced laminates with damage  

Science Journals Connector (OSTI)

Abstract When loaded normal to the fiber direction, transverse cracks often form in the matrix of polymeric composites. Transverse softening has been widely studied, where agreement between models and experiment is common. By comparison, shear softening from transverse cracks has received little attention, and tends not to agree with predictions. The discrepancy between models and observations may be due to the presence of a traction between the crack surfaces. A closed form solution is proposed for the shear stressstrain field of a cracked laminate by replacing the cracks with cohesive zones. The constitutive equations of the crack laminate were derived including the effects of internal tractions and transverse stress on the shear modulus. The analytical solution resulted in good agreement with experimental measurements.

Mohammedmahdi Salavatian; Lloyd Smith

2014-01-01T23:59:59.000Z

466

CFD Modeling of a CFB Riser Using Improved Inlet Boundary Conditions  

Science Journals Connector (OSTI)

A computational fluid dynamics (CFD) model based on Eulerian?Eulerian approach coupled with granular kinetics theory was adopted to investigate the hydrodynamics and flow structures in a circulating fluidized bed (CFB) riser column. A new approach to specify the inlet boundary conditions was proposed in this study to simulate gas?solids flow in CFB risers more accurately. Simulation results were compared with the experimental data and good agreement between the numerical results and experimental data was observed under different operating conditions which indicates the effectiveness and accuracy of the CFD model with the proposed inlet boundary conditions. The results also illustrate a clear core annulus structure in the CFB riser under all operating conditions both experimentally and numerically.

B. T. Peng; C. Zhang; J. X. Zhu; X. B. Qi

2010-01-01T23:59:59.000Z

467

Modeling Merging Galaxies using MINGA - Improving Restricted N-body by Dynamical Friction  

E-Print Network (OSTI)

Modeling interacting galaxies to reproduce observed systems is still a challenge due to the extended parameter space (among other problems). Orbit and basic galaxy parameters can be tackled by fast simulation techniques like the restricted N-body method, applied in the fundamental work by Toomre & Toomre (1972). This approach allows today for the study of millions of models in a short time. One difficulty for the classical restricted N-body method is the missing orbital decay, not allowing for galaxy mergers. Here we present an extension of the restricted N-body method including dynamical friction. This treatment has been developed by a quantitative comparison with a set of self-consistent merger simulations. By varying the dynamical friction (formalism, strength and direction), we selected the best-fitting parameters for a set of more than 250000 simulations. We show that our treatment reliably reproduces the orbital decay and tidal features of merging disk galaxies for mass ratios up to q=1/3 between host and satellite. We implemented this technique into our genetic algorithm based modeling code MINGA and present first results.

Hanns P. Petsch; Christian Theis

2008-10-03T23:59:59.000Z

468

Improving the {sup 33}S(p,{gamma}){sup 34}Cl Reaction Rate for Models of Classical Nova Explosions  

SciTech Connect

Reduced uncertainty in the thermonuclear rate of the {sup 33}S(p,{gamma}){sup 34}Cl reaction would help to improve our understanding of nucleosynthesis in classical nova explosions. At present, models are generally in concordance with observations that nuclei up to roughly the calcium region may be produced in these explosive phenomena; better knowledge of this rate would help with the quantitative interpretation of nova observations over the S-Ca mass region, and contribute towards the firm establishment of a nucleosynthetic endpoint. As well, models find that the ejecta of nova explosions on massive oxygen-neon white dwarfs may contain as much as 150 times the solar abundance of {sup 33}S. This characteristic isotopic signature of a nova explosion could possibly be observed through the analysis of microscopic grains formed in the environment surrounding a nova and later embedded within primitive meteorites. An improved {sup 33}S(p,{gamma}){sup 34}Cl rate (the principal destruction mechanism for {sup 33}S in novae) would help to ensure a robust model prediction for the amount of {sup 33}S that may be produced. Finally, constraining this rate could confirm or rule out the decay of an isomeric state of {sup 34}Cl(E{sub x} = 146 keV, t{sub 1/2} = 32 m) as a source for observable gamma-rays from novae. We have performed several complementary experiments dedicated to improving our knowledge of the {sup 33}S(p,{gamma}){sup 34}Cl rate, using both indirect methods (measurement of the {sup 34}S({sup 3}He,t){sup 34}Cl and {sup 33}S({sup 3}He,d){sup 34}Cl reactions with the Munich Q3D spectrograph) and direct methods (in normal kinematics at CENPA, University of Washington, and in inverse kinematics with the DRAGON recoil mass separator at TRIUMF). Our results will be used with nova models to facilitate comparisons of model predictions with present and future nova observables.

Parikh, A.; Faestermann, Th.; Kruecken, R.; Bildstein, V.; Bishop, S.; Eppinger, K.; Herlitzius, C.; Lepyoshkina, O.; Maierbeck, P.; Seiler, D.; Wimmer, K. [Physik Department E12, Technische Universitaet Muenchen, D-85748, Garching (Germany); Hertenberger, R.; Wirth, H.-F. [Fakultaet fuer Physik, Ludwig-Maximilians-Universitaet Muenchen, D-85748 Garching (Germany); Fallis, J.; Hager, U.; Hutcheon, D.; Ruiz, Ch.; Buchmann, L.; Ottewell, D. [TRIUMF, Vancouver, BC, V6T 2A3 (Canada); Freeman, B. [Center for Experimental Nuclear Physics and Astrophysics, University of Washington, Seattle, WA 98195 (United States)

2011-10-28T23:59:59.000Z

469

The Upper Atmosphere Observatory  

Science Journals Connector (OSTI)

...with *the plasma frethe progress...explorcreated an even larger number of...the upper atmosphere and ionosphere...the upper atmosphere. For this...ionospheric plasma motion simul-taneously...field is large, the horizontal...resolved. The atmospheric gravity waves...simul-taneously at a large number of...two regions plasma drifts separated...

J. V. Evans

1972-05-05T23:59:59.000Z

470

The Upper Atmosphere Observatory  

Science Journals Connector (OSTI)

...DATA, JOURNAL OF ATMOSPHERIC AND TERRESTRIAL...IN NEAR-EARTH PLASMA, SPACE SCIENCE...INVESTIGATION OF WHISTLING ATMOSPHERICS, PHILOSOPHICAL...TRANSPOLAR EXOSPHERIC PLASMA .1. PLASMASPHERE...dynamics of the upper atmosphere. For this purpose...the ionospheric plasma motion simul-taneously...

J. V. Evans

1972-05-05T23:59:59.000Z

471

5, 60416076, 2005 Atmospheric  

E-Print Network (OSTI)

opportunity to examine atmospheric oxidation in a megacity that has more pollution than typical USACPD 5, 6041­6076, 2005 Atmospheric oxidation in the Mexico City Metropolitan Area T. R. Shirley et.atmos-chem-phys.org/acpd/5/6041/ SRef-ID: 1680-7375/acpd/2005-5-6041 European Geosciences Union Atmospheric Chemistry

Boyer, Edmond

472

PNNL: Atmospheric Sciences & Global Change - Fundamental & Computational  

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

Science and Global Change Science and Global Change Our researchers are transforming the nation's ability to predict climate change and its impacts. PNNL's research is expanding knowledge of fundamental atmospheric processes, developing state-of-the-art modeling capabilities, and improving understanding of how climate, energy, water, and land systems interact. Working across disciplines, we integrate theory, measurements, and modeling at molecular to global scales. Read more... aerial irrigation green circles Plugging Water's Effects in an Earth System Model In two studies led by Pacific Northwest National Laboratory, researchers simulated how irrigation from both surface water and groundwater affects the Earth's water and energy budget. The two studies highlight the challenges for Earth system models to include a more complete

473

Atmospheric Carbon Dioxide Variability in the Community Earth System Model: Evaluation and Transient Dynamics during the Twentieth and Twenty-First Centuries  

Science Journals Connector (OSTI)

Changes in atmospheric CO2 variability during the twenty-first century may provide insight about ecosystem responses to climate change and have implications for the design of carbon monitoring programs. This paper describes changes in the three-...

Gretchen Keppel-Aleks; James T. Randerson; Keith Lindsay; Britton B. Stephens; J. Keith Moore; Scott C. Doney; Peter E. Thornton; Natalie M. Mahowald; Forrest M. Hoffman; Colm Sweeney; Pieter P. Tans; Paul O. Wennberg; Steven C. Wofsy

2013-07-01T23:59:59.000Z

474

Modeling of underwater noise from pile driving using coupled finite element and parabolic equation model with improved parabolic equation starting field  

Science Journals Connector (OSTI)

An offshore wind farm will be constructed in the Yellow Sea west of Korean Peninsula where there are extensive fishing activity and numerous fishery farms. To study the effect of underwater piling noise on fishing and marine lives we model the pile driving noise propagation using coupled FE and PE model. The near-field noise is computed by FE model considering detailed specifications of the pile driving system. We apply 2D axis-symmetric geometry and utilize acoustic structure interaction analysis in the frequency domain. The FE results are used to compose the starting field for PE model where appropriate range selection is an important factor to cover most of the contributing ray paths. Extrapolation technique to compensate the lack of FE data and the numerical filtering method to smooth the FE result are discussed. In the far-field the noise propagation is modeled by the split step Pade PE algorithm. The improved PE starting field seems to give refined result than previous coupled model.

Jungyong Park

2013-01-01T23:59:59.000Z

475

Using high-frequency data and time series models to improve yield management  

Science Journals Connector (OSTI)

High-frequency (less than monthly) time series data provide valuable information for designing the adequate yield policy of the organisation. However, it is not easy to extract this information from raw data; although the evolution of the series is usually induced by stable patterns of behaviour of the economic agents, these patterns are so complex that simple smoothing techniques or subjective forecasting cannot consider all underlying factors. In this paper, we discuss time series models as a tool for carrying out a full and efficient analysis. The main ideas are illustrated with an application to Spanish daily electricity consumption.

<