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

Improved Meteorological Input for Atmospheric Release Decision support Systems and an Integrated LES Modeling System for Atmospheric Dispersion of Toxic Agents: Homeland Security Applications  

SciTech Connect (OSTI)

When hazardous material is accidently or intentionally released into the atmosphere, emergency response organizations look to decision support systems (DSSs) to translate contaminant information provided by atmospheric models into effective decisions to protect the public and emergency responders and to mitigate subsequent consequences. The Department of Homeland Security (DHS)-led Interagency Modeling and Atmospheric Assessment Center (IMAAC) is one of the primary DSSs utilized by emergency management organizations. IMAAC is responsible for providing 'a single piont for the coordination and dissemination of Federal dispersion modeling and hazard prediction products that represent the Federal position' during actual or potential incidents under the National Response Plan. The Department of Energy's (DOE) National Atmospheric Release Advisory Center (NARAC), locatec at the Lawrence Livermore National Laboratory (LLNL), serves as the primary operations center of the IMAAC. A key component of atmospheric release decision support systems is meteorological information - models and data of winds, turbulence, and other atmospheric boundary-layer parameters. The accuracy of contaminant predictions is strongly dependent on the quality of this information. Therefore, the effectiveness of DSSs can be enhanced by improving the meteorological options available to drive atmospheric transport and fate models. The overall goal of this project was to develop and evaluate new meteorological modeling capabilities for DSSs based on the use of NASA Earth-science data sets in order to enhance the atmospheric-hazard information provided to emergency managers and responders. The final report describes the LLNL contributions to this multi-institutional effort. LLNL developed an approach to utilize NCAR meteorological predictions using NASA MODIS data for the New York City (NYC) region and demonstrated the potential impact of the use of different data sources and data parameterizations on IMAAC/NARAC fate and transport predictions. A case study involving coastal sea breeze circulation patterns in the NYC region was used to investigate the sensitivity of atmospheric dispersion results on the source of three-dimensional wind field data.

Arnold, E; Simpson, M; Larsen, S; Gash, J; Aluzzi, F; Lundquist, J; Sugiyama, G

2010-04-26T23:59:59.000Z

2

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

3

Atmosphere Model  

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

AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE:1 First Use of Energy for All Purposes (Fuel and Nonfuel),Feet) Year Jan Feb Mar Apr MayAtmospheric Optical Depth (AOD)ProductssondeadjustsondeadjustAbout theOFFICEAmesApplication2ArgonneAssemblyDemandPlasma4 Medicare5Dust

4

Improving Convection Parameterization Using ARM Observations and NCAR Community Atmosphere Model  

SciTech Connect (OSTI)

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

5

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

6

Global Simulations of Ice nucleation and Ice Supersaturation with an Improved Cloud Scheme in the Community Atmosphere Model  

SciTech Connect (OSTI)

A process-based treatment of ice supersaturation and ice-nucleation is implemented in the National Center for Atmospheric Research (NCAR) Community Atmosphere Model (CAM). The new scheme is designed to allow (1) supersaturation with respect to ice, (2) ice nucleation by aerosol particles and (3) ice cloud cover consistent with ice microphysics. The scheme is implemented with a 4-class 2 moment microphysics code and is used to evaluate ice cloud nucleation mechanisms and supersaturation in CAM. The new model is able to reproduce field observations of ice mass and mixed phase cloud occurrence better than previous versions of the model. Simulations indicate heterogeneous freezing and contact nucleation on dust are both potentially important over remote areas of the Arctic. Cloud forcing and hence climate is sensitive to different formulations of the ice microphysics. Arctic radiative fluxes are sensitive to the parameterization of ice clouds. These results indicate that ice clouds are potentially an important part of understanding cloud forcing and potential cloud feedbacks, particularly in the Arctic.

Gettelman, A.; Liu, Xiaohong; Ghan, Steven J.; Morrison, H.; Park, Sungsu; Conley, Andrew; Klein, Stephen A.; Boyle, James; Mitchell, David; Li, J-L F.

2010-09-28T23:59:59.000Z

7

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

8

A Community Atmosphere Model with Superparameterized Clouds  

SciTech Connect (OSTI)

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

9

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

10

A Grid of 3D Stellar Atmosphere Models of Solar Metallicity: I. General Properties, Granulation and Atmospheric Expansion  

E-Print Network [OSTI]

Present grids of stellar atmosphere models are the workhorses in interpreting stellar observations, and determining their fundamental parameters. These models rely on greatly simplified models of convection, however, lending less predictive power to such models of late type stars. We present a grid of improved and more reliable stellar atmosphere models of late type stars, based on deep, 3D, convective, stellar atmosphere simulations. This grid is to be used in general for interpreting observations, and improve stellar and asteroseismic modeling. We solve the Navier Stokes equations in 3D and concurrent with the radiative transfer equation, for a range of atmospheric parameters, covering most of stellar evolution with convection at the surface. We emphasize use of the best available atomic physics for quantitative predictions and comparisons with observations. We present granulation size, convective expansion of the acoustic cavity, asymptotic adiabat, as function of atmospheric parameters. These and other re...

Trampedach, Regner; Collet, Remo; Nordlund, Ĺke; Stein, Robert F

2013-01-01T23:59:59.000Z

11

Atmospheric Chemistry, Modeling, and Biogeochemistry of Mercury  

E-Print Network [OSTI]

Atmospheric Chemistry, Modeling, and Biogeochemistry of Mercury Noelle Eckley Selin *Reprinted from Mercury in the Environment: Pattern and Process (Chapter 5) pp. 73-80 Copyright © 2012 with kind, and Biogeochemistry of Mercury NOELLE ECKLEY SELIN and their distribution in the atmosphere. This includes

12

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

13

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

14

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

15

Atmospheric model intercomparison project: Monsoon simulations  

SciTech Connect (OSTI)

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

16

Atmospheric Climate Model Experiments Performed at Multiple Horizontal Resolutions  

SciTech Connect (OSTI)

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

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

2007-12-21T23:59:59.000Z

17

Atmospheric transmittance model for photosynthetically active radiation  

SciTech Connect (OSTI)

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, Ĺngström'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

18

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

19

Discrete Packet Analysis for Improved Atmospheric Rejection on Modulated Laser Signals  

SciTech Connect (OSTI)

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

20

Regional forecasting with global atmospheric models; Final report  

SciTech Connect (OSTI)

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

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

Surface Modification by Atmospheric Pressure Plasma for Improved Bonding.  

E-Print Network [OSTI]

??An atmospheric pressure plasma source operating at temperatures below 150°C 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

22

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

23

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

24

Modeling decade to century scale variability in the atmosphere/ocean [Final report  

SciTech Connect (OSTI)

Study of the intrinsic variability of a coupled atmosphere/ocean model called The Fast Ocean/Atmosphere Model (FOAM).

Kutzbach, John E.

2002-02-04T23:59:59.000Z

25

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

26

Application of Improved Radiation Modeling to General Circulation Models  

SciTech Connect (OSTI)

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

27

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

28

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

29

A Grid of FASTWIND NLTE Model Atmospheres of Massive Stars  

E-Print Network [OSTI]

In the last few years our knowledge of the physics of massive stars has improved tremendously. However, further investigations are still needed, especially regarding accurate calibrations of their fundamental parameters. To this end, we have constructed a comprehensive grid of NLTE model atmospheres and corresponding synthetic spectra in the massive star domain. The grid covers the complete B type spectral range, extended to late O on the hot side and early A on the cool side, from supergiants to dwarfs and from weak stellar winds to very strong ones. It has been calculated with the latest version of the FASTWIND code. The analysis of an extensive sample of OB stars in the framework of the COROT space mission will lead to accurate calibrations of effective temperatures, gravities, mass loss rates etc. This paper contains a detailed description of the grid, which has been baptised as BSTAR06 and which will be available for further research in the near future.

K. Lefever; J. Puls; C. Aerts

2006-09-22T23:59:59.000Z

30

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

31

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

32

Atmospheric Modelling of Greenhouse Gases and Air Quality  

E-Print Network [OSTI]

. Increase in mixing height (h) entrains (draws in) air from above the box #12Atmospheric Modelling of Greenhouse Gases and Air Quality John C. Lin Courtenay Strong University of Utah: February 20th, 2013 Department of Atmospheric Sciences University of Utah #12;Outline ·CO2 ó Air

Tipple, Brett

33

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 res- olution system for modeling regional air pollution based on the chemical transport model STEM. Keywords: Air Pollution Modeling, Adaptive Mesh Refinement. 1 Introduction Inadequate grid resolution can

Sandu, Adrian

34

Computer support to run models of the atmosphere. Final report  

SciTech Connect (OSTI)

This research is focused on a better quantification of the variations in CO{sub 2} exchanges between the atmosphere and biosphere and the factors responsible for these exchangers. The principal approach is to infer the variations in the exchanges from variations in the atmospheric CO{sub 2} distribution. The principal tool involves using a global three-dimensional tracer transport model to advect and convect CO{sub 2} in the atmosphere. The tracer model the authors used was developed at the Goddard institute for Space Studies (GISS) and is derived from the GISS atmospheric general circulation model. A special run of the GCM is made to save high-frequency winds and mixing statistics for the tracer model.

Fung, I.

1996-08-30T23:59:59.000Z

35

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

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

36

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

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

37

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

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

38

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

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

39

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

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

40

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

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

Predicting Improved Chiller Performance Through Thermodynamic Modeling  

E-Print Network [OSTI]

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

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

42

Using Neural Networks Atmospheric Model Physics  

E-Print Network [OSTI]

Outline · Background ­ GCM · Radiation · Convection ­ Neural Networks · NN Emulations of Existing Model · Major components of P = {R, W, C, T, S, CH}: ­ R - radiation (long & short wave processes): AER Inc ­ S ­ land, ocean, ice ­ air interaction ­ CH ­ chemistry (aerosols) · Components of P are 1-D

Anisimov, Mikhail

43

Modeled atmospheric radon concentrations from uranium mines  

SciTech Connect (OSTI)

Uranium mining and milling operations result in the release of radon from numerous sources of various types and strengths. The US Environmental Protection Agency (EPA) under the Clean Air Act, is assessing the health impact of air emissions of radon from underground uranium mines. In this case, the radon emissions may impact workers and residents in the mine vicinity. To aid in this assessment, the EPA needs to know how mine releases can affect the radon concentrations at populated locations. To obtain this type of information, Pacific Northwest Laboratory used the radon emissions, release characteristics and local meterological conditions for a number of mines to model incremental radon concentrations. Long-term, average, incremental radon concentrations were computed based on the best available information on release rates, plume rise parameters, number and locations of vents, and local dispersion climatology. Calculations are made for a model mine, individual mines, and multiple mines. Our approach was to start with a general case and then consider specific cases for comparison. A model underground uranium mine was used to provide definition of the order of magnitude of typical impacts. Then computations were made for specific mines using the best mine-specific information available for each mine. These case study results are expressed as predicted incremental radon concentration contours plotted on maps with local population data from a previous study. Finally, the effect of possible overlap of radon releases from nearby mines was studied by calculating cumulative radon concentrations for multiple mines in a region with many mines. The dispersion model, modeling assumptions, data sources, computational procedures, and results are documented in this report. 7 refs., 27 figs., 18 tabs.

Droppo, J.G.

1985-04-01T23:59:59.000Z

44

Oxygen line formation in 3D hydrodynamical model atmospheres  

E-Print Network [OSTI]

The formation of [O I], O I and OH lines in metal-poor stars has been studied by means of 3D hydrodynamical model atmospheres. For O I detailed 3D non-LTE calculations have been performed. While the influence of 3D model atmospheres is minor for [O I] and O I lines, the very low temperatures encountered at low metallicities have a drastic impact on the OH lines. As a result, the derived O abundances are found to be systematically overestimated in 1D analyses, casting doubts on the recent claims for a monotonic increase in [O/Fe] towards lower metallicities.

M. Asplund

2000-11-02T23:59:59.000Z

45

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

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

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

46

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

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

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

47

Graduate Opportunities in Atmospheric Modeling to Understand Greenhouse Gas Emissions  

E-Print Network [OSTI]

Graduate Opportunities in Atmospheric Modeling to Understand Greenhouse Gas Emissions University://www.atmos.utah.edu/) seeks multiple graduate students to study greenhouse gas emissions associated with urban development greenhouse gas emissions. Samples of guiding questions as part of the projects include: · What can explain

Lin, John Chun-Han

48

Modeling the atmospheric inputs of MTBE to groundwater systems  

SciTech Connect (OSTI)

A numerical transport model was used to calculate the movement of methyl-t-butyl ether (MTBE) and several other volatile organic compounds (VOCs) from the atmosphere downward through the unsaturated zone and into shallow groundwater. Simulations were carried out for periods as long as 10 years to investigate whether a gaseous atmospheric MTBE source at typical ambient concentrations could account for the presence of MTBE in shallow groundwater at the types of low ug/L levels that have been found during the National Water Quality Assessment Program currently being conducted by the US Geological Survey. The simulations indicate that downward movement of MTBE to shallow groundwater will be very slow when there is no net downward movement of water through the vadose zone. For example, for a vadose zone composed of fine sand, and assuming tens of cm of infiltration, then only a few years will be required for water at a water table that is 5.0 m below ground surface to attain MTBE levels that correspond to saturation with respect to the atmospheric source gaseous concentration. An on/off atmospheric source, as might occur in the seasonal use of MTBE, will lead to concentrations in shallow groundwater that correspond to saturation with the time-averaging atmospheric source concentration.

Pankow, J.F.; Johnson, R.L. [Oregon Graduate Inst., Portland, OR (United States). Dept. of Environmental Science and Engineering; Thomson, N.R. [Univ. of Waterloo, Ontario (Canada). Dept. of Civil Engineering

1995-12-31T23:59:59.000Z

49

Single-Column Modeling, GCM Parameterizations and Atmospheric Radiation Measurement Data  

SciTech Connect (OSTI)

Our overall goal is identical to that of the Atmospheric Radiation Measurement (ARM) Program: the development of new and improved parameterizations of cloud-radiation effects and related processes, using ARM data at all three ARM sites, and the implementation and testing of these parameterizations in global and regional models. To test recently developed prognostic parameterizations based on detailed cloud microphysics, we have first compared single-column model (SCM) output with ARM observations at the Southern Great Plains (SGP), North Slope of Alaska (NSA) and Topical Western Pacific (TWP) sites. We focus on the predicted cloud amounts and on a suite of radiative quantities strongly dependent on clouds, such as downwelling surface shortwave radiation. Our results demonstrate the superiority of parameterizations based on comprehensive treatments of cloud microphysics and cloud-radiative interactions. At the SGP and NSA sites, the SCM results simulate the ARM measurements well and are demonstrably more realistic than typical parameterizations found in conventional operational forecasting models. At the TWP site, the model performance depends strongly on details of the scheme, and the results of our diagnostic tests suggest ways to develop improved parameterizations better suited to simulating cloud-radiation interactions in the tropics generally. These advances have made it possible to take the next step and build on this progress, by incorporating our parameterization schemes in state-of-the-art 3D atmospheric models, and diagnosing and evaluating the results using independent data. Because the improved cloud-radiation results have been obtained largely via implementing detailed and physically comprehensive cloud microphysics, we anticipate that improved predictions of hydrologic cycle components, and hence of precipitation, may also be achievable. We are currently testing the performance of our ARM-based parameterizations in state-of-the--art global and regional models. One fruitful strategy for evaluating advances in parameterizations has turned out to be using short-range numerical weather prediction as a test-bed within which to implement and improve parameterizations for modeling and predicting climate variability. The global models we have used to date are the CAM atmospheric component of the National Center for Atmospheric Research (NCAR) CCSM climate model as well as the National Centers for Environmental Prediction (NCEP) numerical weather prediction model, thus allowing testing in both climate simulation and numerical weather prediction modes. We present detailed results of these tests, demonstrating the sensitivity of model performance to changes in parameterizations.

Somerville, R.C.J.; Iacobellis, S.F.

2005-03-18T23:59:59.000Z

50

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

51

Modeling Activities in the Department of Energy’s Atmospheric Sciences Program  

SciTech Connect (OSTI)

The Department of Energy's Atmospheric Science Program (ASP) conducts research pertinent to radiative forcing of climate change by atmospheric aerosols. The program consists of approximately 40 highly interactive peer-reviewed research projects that examine aerosol properties and processes and the evolution of aerosols in the atmosphere. Principal components of the program are instrument development, laboratory experiments, field studies, theoretical investigations, and modeling. The objectives of the Program are to 1) improve the understanding of aerosol processes associated with light scattering and absorption properties and interactions with clouds that affect Earth's radiative balance and to 2) develop model-based representations of these processes that enable the effects of aerosols on Earth's climate system to be properly represented in global-scale numerical climate models. Although only a few of the research projects within ASP are explicitly identified as primarily modeling activities, modeling actually comprises a substantial component of a large fraction of ASP research projects. This document describes the modeling activities within the Program as a whole, the objectives and intended outcomes of these activities, and the linkages among the several modeling components and with global-scale modeling activities conducted under the support of the Department of Energy's Climate Sciences Program and other aerosol and climate research programs.

Fast, Jerome D.; Ghan, Steven J.; Schwartz, Stephen E.

2009-03-01T23:59:59.000Z

52

Causes and Implications of Persistent Atmospheric Carbon Dioxide Biases in Earth System Models  

SciTech Connect (OSTI)

The strength of feedbacks between a changing climate and future CO2 concentrations are uncertain and difficult to predict using Earth System Models (ESMs). We analyzed emission-driven simulations--in which atmospheric CO2 levels were computed prognostically--for historical (1850-2005) and future periods (RCP 8.5 for 2006-2100) produced by 15 ESMs for the Fifth Phase of the Coupled Model Intercomparison Project (CMIP5). Comparison of ESM prognostic atmospheric CO2 over the historical period with observations indicated that ESMs, on average, had a small positive bias in predictions of contemporary atmospheric CO2. Weak ocean carbon uptake in many ESMs contributed to this bias, based on comparisons with observations of ocean and atmospheric anthropogenic carbon inventories. We found a significant linear relationship between contemporary atmospheric CO2 biases and future CO2 levels for the multi-model ensemble. We used this relationship to create a contemporary CO2 tuned model (CCTM) estimate of the atmospheric CO2 trajectory for the 21st century. The CCTM yielded CO2 estimates of 600 {plus minus} 14 ppm at 2060 and 947 {plus minus} 35 ppm at 2100, which were 21 ppm and 32 ppm below the multi-model mean during these two time periods. Using this emergent constraint approach, the likely ranges of future atmospheric CO2, CO2-induced radiative forcing, and CO2-induced temperature increases for the RCP 8.5 scenario were considerably narrowed compared to estimates from the full ESM ensemble. Our analysis provided evidence that much of the model-to-model variation in projected CO2 during the 21st century was tied to biases that existed during the observational era, and that model differences in the representation of concentration-carbon feedbacks and other slowly changing carbon cycle processes appear to be the primary driver of this variability. By improving models to more closely match the long-term time series of CO2 from Mauna Loa, our analysis suggests uncertainties in future climate projections can be reduced.

Hoffman, Forrest M [ORNL] [ORNL; Randerson, James T. [University of California, Irvine] [University of California, Irvine; Arora, Vivek K. [Canadian Centre for Climate Modelling and Analysis, Meteorological Service of Canada] [Canadian Centre for Climate Modelling and Analysis, Meteorological Service of Canada; Bao, Qing [State Key Laboratory of Numerical Modeling for Atmospheric Sciences and Geophysical Fluid Dynamics] [State Key Laboratory of Numerical Modeling for Atmospheric Sciences and Geophysical Fluid Dynamics; Cadule, Patricia [Institut Pierre Simon Laplace, Laboratoire des Sciences du Climat et de l'Environment] [Institut Pierre Simon Laplace, Laboratoire des Sciences du Climat et de l'Environment; Ji, Duoying [State Key Laboratory of Earth Surface Processes and Resource Ecology, Beijing] [State Key Laboratory of Earth Surface Processes and Resource Ecology, Beijing; Jones, Chris D. [Hadley Centre, U.K. Met Office] [Hadley Centre, U.K. Met Office; Kawamiya, Michio [Japan Agency for Marine-Earth Science and Technology (JAMSTEC)] [Japan Agency for Marine-Earth Science and Technology (JAMSTEC); Khatiwala, Samar [Lamont-Doherty Earth Observatory, Columbia University, Palisades, NY] [Lamont-Doherty Earth Observatory, Columbia University, Palisades, NY; Lindsay, Keith [National Center for Atmospheric Research (NCAR)] [National Center for Atmospheric Research (NCAR); Obata, Atsushi [Meteorological Research Institute, Japan] [Meteorological Research Institute, Japan; Shevliakova, Elena [Princeton University] [Princeton University; Six, Katharina D. [Max Planck Institute for Meteorology, Hamburg, Germany] [Max Planck Institute for Meteorology, Hamburg, Germany; Tjiputra, Jerry F. [Uni Climate, Uni Research] [Uni Climate, Uni Research; Volodin, Evgeny M. [Institute of Numerical Mathematics, Russian Academy of Science, Moscow] [Institute of Numerical Mathematics, Russian Academy of Science, Moscow; Wu, Tongwen [China Meteorological Administration (CMA), Beijing] [China Meteorological Administration (CMA), Beijing

2014-01-01T23:59:59.000Z

53

Thermal shallow water models of geostrophic turbulence in Jovian atmospheres  

SciTech Connect (OSTI)

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

54

An Improved Global Model for Air-Sea Exchange of Mercury: High  

E-Print Network [OSTI]

An Improved Global Model for Air-Sea Exchange of Mercury: High Concentrations over the North by inputs from Hg enriched subsurface waters through entrainment and Ekman pumping. Globally, subsurface). Previous efforts to model Hg air-sea exchange (2) and atmospheric transport (4-6) have been unable

Holmes, Christopher D.

55

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

E-Print Network [OSTI]

.................................................................................................. 5 Soil energy and water balanceThe Soil-Plant-Atmosphere model Manual, version 1.3, September 2005 Dr. Mathew Williams School handbook v 1.2 -2- Index The Soil-Plant-Atmosphere model

56

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

Broader source: Energy.gov (indexed) [DOE]

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

57

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

SciTech Connect (OSTI)

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

58

Atmospheric Dispersion Modeling: Challenges of the Fukushima Daiichi Response  

SciTech Connect (OSTI)

The U.S. Department of Energy’s (DOE) National Atmospheric Release Advisory Center (NARAC) provided a wide range of predictions and analyses as part of the response to the Fukushima Daiichi Nuclear Power Plant accident. This work encompassed: weather forecasts and atmospheric transport predictions, estimates of possible dose in Japan based on hypothetical U.S. Nuclear Regulatory Commission scenarios of potential radionuclide releases, predictions of possible plume arrival times and dose levels at U.S. locations, and source estimation and plume model refinement. An overview of NARAC response activities is provided, along with a more in-depth discussion of some of NARAC’s preliminary source reconstruction analyses. NARAC optimized the overall agreement of model predictions to dose rate measurements using statistical comparisons of data and model values paired in space and time. Estimated emission rates varied depending on the choice of release assumptions (e.g., time-varying vs. constant release rates), the radionuclide mix, meteorology, and/or the radiological data used in the analysis. Results were found to be consistent with other studies within expected uncertainties, despite the application of different source estimation methodologies and the use of significantly different radiological measurement data. A discussion of some of the operational and scientific challenges encountered during the response, along with recommendations for future work, is provided.

Sugiyama, Gayle [Lawrence Livermore National Laboratory; Nasstrom, John [Lawrence Livermore National Laboratory; Pobanz, Brenda [Lawrence Livermore National Laboratory; Foster, Kevin [Lawrence Livermore National Laboratory; Simpson, Matthew [Lawrence Livermore National Laboratory; Vogt, Phil [Lawrence Livermore National Laboratory; Aluzzi, Fernando [Lawrence Livermore National Laboratory; Homann, Steve [Lawrence Livermore National Laboratory

2012-05-01T23:59:59.000Z

59

Modeling atmospheric deposition using a stochastic transport model  

SciTech Connect (OSTI)

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

60

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

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

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

Mathematical Modeling of Carbon Dioxide Injection in the Subsurface for Improved Hydrocarbon Recovery and Sequestration  

E-Print Network [OSTI]

Mathematical Modeling of Carbon Dioxide Injection in the Subsurface for Improved Hydrocarbon Recovery and Sequestration Philip C. Myint, Laurence Rongy, Kjetil B. Haugen, Abbas Firoozabadi Department. Combustion of fossil fuels contributes to rising atmospheric carbon dioxide (CO2) levels that have been

Firoozabadi, Abbas

62

Final Report - From Measurements to Models: Cross-Comparison of Measured and Simulated Behavioral States of the Atmosphere  

SciTech Connect (OSTI)

The ARM sites and the ARM Mobile Facility (AMF) were constructed to make measurements of the atmosphere and radiation system in order to quantify deficiencies in the simulation of clouds within models and to make improvements in those models. While the measurement infrastructure of ARM is well-developed and a model parameterization testbed capability has been established, additional effort is needed to develop statistical techniques which permit the comparison of simulation output from atmospheric models with actual measurements. Our project establishes a new methodology for objectively comparing ARM measurements to the outputs of leading global climate models and reanalysis data. The quantitative basis for this comparison is provided by a statistical procedure which establishes an exhaustive set of mutually-exclusive, recurring states of the atmosphere from sets of multivariate atmospheric and cloud conditions, and then classifies multivariate measurements or simulation outputs into those states. Whether measurements and models classify the atmosphere into the same states at specific locations through time provides an unequivocal comparison result. Times and locations in both geographic and state space of model-measurement agreement and disagreement will suggest directions for the collection of additional measurements at existing sites, provide insight into the global representativeness of the current ARM sites (suggesting locations and times for use of the AMF), and provide a basis for improvement of models. Two different analyses were conducted: One, using the Parallel Climate Model, focused on an IPCC climate change scenario and clusters that characterize long-term changes in the hydrologic cycle. The other, using the GISS Model E GCM and the ARM Active Remotely Sensed Cloud Layers product, explored current climate cloud regimes in the Tropical West Pacific.

Del Genio, Anthony D; Hoffman, Forrest M; Hargrove, Jr, William W

2007-10-22T23:59:59.000Z

63

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

64

Process Modeling for Process Improvement A Process Conformance Approach  

E-Print Network [OSTI]

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

65

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

66

Formation of algae growth constitutive relations for improved algae modeling.  

SciTech Connect (OSTI)

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

67

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

SciTech Connect (OSTI)

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.

Prusa, Joseph

2012-05-08T23:59:59.000Z

68

Spatio-temporal statistical models with applications to atmospheric processes  

SciTech Connect (OSTI)

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

69

E-Print Network 3.0 - atmospheric climate model Sample Search...  

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

changes in atmospheric condensation nuclei (CN... capabilities of the Earth System Models and reduce ... Source: Knuth, Kevin H. - Department of Physics, State...

70

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

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

1, December 2010 draft Summary: is to integrate atmospheric chemistry into Earth System Models (ESMs) that attempt to fully couple the physics... Guy P. Brasseur and Daniel...

71

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

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

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

72

ISO-SWS calibration and the accurate modelling of cool-star atmospheres: I. Method  

E-Print Network [OSTI]

A detailed spectroscopic study of the ISO-SWS data of the red giant Alpha Tau is presented, which enables not only the accurate determination of the stellar parameters of Alpha Tau, but also serves as a critical review of the ISO-SWS calibration. This study is situated in a broader context of an iterative process in which both accurate observations of stellar templates and cool star atmosphere models are involved to improve the ISO-SWS calibration process as well as the theoretical modelling of stellar atmospheres. Therefore a sample of cool stars, covering the whole A0 -- M8 spectral classification, has been observed in order to disentangle calibration problems and problems in generating the theoretical models and corresponding synthetic spectrum. By using stellar parameters found in the literature large discrepancies were seen between the ISO-SWS data and the generated synthetic spectrum of Alpha Tau. A study of the influence of various stellar parameters on the theoretical models and synthetic spectra, in conjunction with the Kolmogorov-Smirnov test to evaluate objectively the goodness-of-fit, enables us to pin down the stellar parameters with a high accuracy: Teff = 3850 +/- 70 K, log g = 1.50 +/- 0.15, M = 2.3 +/- 0.8 Msun, z = -0.15 +/- 0.20 dex, microturbulence = 1.7 +/- 0.3 km/s, 12C/13C= 10 +/- 1, abundance of C = 8.35 +/- 0.20 dex, abundance of N= 8.35 +/- 0.25 dex, abundance of O = 8.83 +/- 0.15 dex and the angular diameter is 20.77 +/- 0.83 mas. These atmospheric parameters were then compared with the results provided by other authors using other methods and/or spectra.

L. Decin; C. Waelkens; K. Eriksson; B. Gustafsson; B. Plez; A. J. Sauval; W. Van Assche; B. Vandenbussche

2000-08-21T23:59:59.000Z

73

Manuscript prepared for Geosci. Model Dev.-Date: 28 May 2013 CHIMERE 2013: a model for regional atmospheric composition  

E-Print Network [OSTI]

is dedicated to regional atmospheric pollution event studies. Since it has now reached a certain level atmospheric composition modelling Laurent MENUT1 , Bertrand BESSAGNET2 , Dmitry KHVOROSTYANOV1 , Matthias dell'Aquila, L'Aquila, Italy 6 NCAR Atmospheric Chemistry Division, 3450 Mitchell Lane, Boulder

Menut, Laurent

74

Efficiency and Sensitivity Analysis of Observation Networks for Atmospheric Inverse Modelling with Emissions  

E-Print Network [OSTI]

The controllability of advection-diffusion systems, subject to uncertain initial values and emission rates, is estimated, given sparse and error affected observations of prognostic state variables. In predictive geophysical model systems, like atmospheric chemistry simulations, different parameter families influence the temporal evolution of the system.This renders initial-value-only optimisation by traditional data assimilation methods as insufficient. In this paper, a quantitative assessment method on validation of measurement configurations to optimize initial values and emission rates, and how to balance them, is introduced. In this theoretical approach, Kalman filter and smoother and their ensemble based versions are combined with a singular value decomposition, to evaluate the potential improvement associated with specific observational network configurations. Further, with the same singular vector analysis for the efficiency of observations, their sensitivity to model control can be identified by deter...

Wu, Xueran; Jacob, Birgit

2015-01-01T23:59:59.000Z

75

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

76

Improvements in Near-Terminator and Nocturnal Cloud Masks using Satellite Imager Data over the Atmospheric Radiation Measurement Sites  

SciTech Connect (OSTI)

Cloud detection using satellite measurements presents a big challenge near the terminator where the visible (VIS; 0.65 {micro}m) channel becomes less reliable and the reflected solar component of the solar infrared 3.9-{micro}m channel reaches very low signal-to-noise ratio levels. As a result, clouds are underestimated near the terminator and at night over land and ocean in previous Atmospheric Radiation Measurement (ARM) Program cloud retrievals using Geostationary Operational Environmental Satellite (GOES) imager data. Cloud detection near the terminator has always been a challenge. For example, comparisons between the CLAVR-x (Clouds from Advanced Very High Resolution Radiometer [AVHRR]) cloud coverage and Geoscience Laser Altimeter System (GLAS) measurements north of 60{sup o}N indicate significant amounts of missing clouds from AVHRR because this part of the world was near the day/night terminator viewed by AVHRR. Comparisons between MODIS cloud products and GLAS at the same regions also shows the same difficulty in the MODIS cloud retrieval (Pavolonis and Heidinger 2005). Consistent detection of clouds at all times of day is needed to provide reliable cloud and radiation products for ARM and other research efforts involving the modeling of clouds and their interaction with the radiation budget. To minimize inconsistencies between daytime and nighttime retrievals, this paper develops an improved twilight and nighttime cloud mask using GOES-9, 10, and 12 imager data over the ARM sites and the continental United States (CONUS).

Trepte, Q.Z.; Minnis, P.; Heck, P.W.; Palikonda, R.

2005-03-18T23:59:59.000Z

77

A MODEL ATMOSPHERE ANALYSIS OF ALPHA AURIGAE A  

SciTech Connect (OSTI)

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

78

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

SciTech Connect (OSTI)

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

79

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 Ă?agedĂ? emissions of primary pollutants or actual production

80

Overturning and wind driven circulation in a low-order ocean-atmosphere model  

E-Print Network [OSTI]

july 2002 Abstract A low-order ocean-atmosphere model is presented which combines coupling through heat exchange at the interface and wind stress forcing. The coupling terms are derived from the boundary conditions and the forcing terms of the constituents. Both the ocean and the atmosphere model are based

van Veen, Lennaert

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

Multiscale models of atmospheric mercury: bromine chemistry, air-sea exchange, and global transport  

E-Print Network [OSTI]

entrainment of RGM-rich air from the free troposphere (25­40%). Oxidation of Hg0 by Cl is minor (3Multiscale models of atmospheric mercury: bromine chemistry, air-sea exchange, and global transport Multiscale models of atmospheric mercury: bromine chemistry, air-sea exchange, and global transport Abstract

Holmes, Christopher D.

82

Annular mode-like responses to external forcings in a simple atmospheric general circulation model  

E-Print Network [OSTI]

In this thesis, I investigate the response of a simple atmospheric general circulation model to applied forcings to learn whether the annular mode patterns are a preferred model response to the forcings. The thesis is ...

Ring, Michael J., 1979-

2008-01-01T23:59:59.000Z

83

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

SciTech Connect (OSTI)

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

84

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

SciTech Connect (OSTI)

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

85

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

SciTech Connect (OSTI)

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

86

A Grid of NLTE Line-Blanketed Model Atmospheres of Early B-type Stars  

E-Print Network [OSTI]

We have constructed a comprehensive grid of 1540 metal line-blanketed, NLTE, plane-parallel, hydrostatic model atmospheres for the basic parameters appropriate to early B-type stars. The BSTAR2006 grid considers 16 values of effective temperatures, 15,000 K grid complements our earlier OSTAR2002 grid of O-type stars (Lanz & Hubeny, 2003, ApJS, 146, 417). The paper contains a description of the BSTAR2006 grid and some illustrative examples and comparisons. NLTE ionization fractions, bolometric corrections, radiative accelerations, and effective gravities are obtained over the parameter range covered by the grid. By extrapolating radiative accelerations, we have determined an improved estimate of the Eddington limit in absence of rotation between 55,000 and 15,000 K. The complete BSTAR2006 grid is available at the TLUSTY website (http://nova.astro.umd.edu).

Thierry Lanz; Ivan Hubeny

2006-11-29T23:59:59.000Z

87

IMPROVING CATASTROPHE MODELING FOR BUSINESS INTERRUPTION INSURANCE NEEDS  

E-Print Network [OSTI]

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

Wang, Hai

88

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

89

Improvement of snowpack simulations in a regional climate model  

SciTech Connect (OSTI)

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

Jin, J.; Miller, N.L.

2011-01-10T23:59:59.000Z

90

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

SciTech Connect (OSTI)

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

91

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

SciTech Connect (OSTI)

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

92

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.

93

Data Collection for Improved Cold Temperature Thermal Modeling  

Broader source: Energy.gov (indexed) [DOE]

FY Data Collection for Improved Cold Temperature Thermal Modeling This presentation does not contain any proprietary, confidential, or otherwise restricted information Forrest...

94

Data Collection for Improved Cold Temperature Thermal Modeling...  

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

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

95

Summary of the March 25--26, 1991 atmospheric model working meeting  

SciTech Connect (OSTI)

Atmospheric transport and diffusion calculations for the initial phase of the Hanford Environmental Dose Reconstruction (HEDR) Project were made using the MESOILT2 computer code (Ramsdell and Burk 1991). This code implemented a Lagrangian trajectory, puff dispersion model using components from other models designed primarily for regulatory applications. Uncertainty in the dispersion calculations was estimated following model calculations. The results of the atmospheric dispersion calculations were summarized in frequency distributions by location for use in preliminary dose calculations.

Ramsdell, J.V.

1992-07-01T23:59:59.000Z

96

Modelling of Stellar Atmospheres IAU Symposium, Vol. xxx, xxxx  

E-Print Network [OSTI]

Abstract. We discuss the dynamics in the outer atmospheres of AGB giants. 1. Motivation Hinkle et al. (1982 with an excitation temperature of about 800-1000 K and an almost zero velocity relative to the stellar systemic molecular envelope", should be common not only in Miras but in evolved red giants in general. 2. Project

97

Lesson Summary Students will use models of Earth's atmosphere  

E-Print Network [OSTI]

to learn about the causes and effects of global warming, the better prepared we may be to deal of human actions. Global warming refers to the rise in temperatures at Earth's surface and lower atmosphere are contributing to global warming. The danger in this warming is that it could disrupt Earth's climate patterns

Mojzsis, Stephen J.

98

ATMOSPHERIC TURBULENCE MODELING AND IMPLICATIONS FOR WIND ENERGY  

E-Print Network [OSTI]

turbines off too early in high winds, or may risk severe damage to the rotors and blades by operating under Introduction Wind turbines sit at the very bottom of the at- mospheric boundary layer, where winds are highly turbulent, shear events are intermittent, and land- atmosphere interactions may be strong. Turbine hub

Chow, Fotini Katopodes

99

Observations and simulations improve space weather models  

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

AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE:1 First Use of Energy for All Purposes (Fuel and Nonfuel),Feet) Year Jan Feb Mar Apr MayAtmosphericNuclear Security Administration the ContributionsArmsSpeedingSpeedingUnder Well-ControlledObservation ofof

100

Improved computer models support genetics research  

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

AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE:1 First Use of Energy for All Purposes (Fuel and Nonfuel),Feet) Year Jan Feb Mar Apr MayAtmospheric Optical Depth7-1D: Vegetation ProposedUsingFun withconfinementEtching.348 270 300 219 255Retrievals of TemperatureSimple

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

A Simple Atmospheric Model of the Local and Teleconnection Responses to Tropical Heating Anomalies  

E-Print Network [OSTI]

the local and remote stationary responses of the atmosphere to tropical heating anomalies is describedA Simple Atmospheric Model of the Local and Teleconnection Responses to Tropical Heating Anomalies and forced with a localized heating for illustration. In the tropics, the baroclinic responses are familiar

Wang, Chunzai

102

Atmospheric transport and dispersion modeling for the Hanford Environmental Dose Reconstruction Project  

SciTech Connect (OSTI)

Radiation doses that may have resulted from operations at the Hanford Site are being estimated in the Hanford Environmental Dose Reconstruction (HEDR) Project. One of the project subtasks, atmospheric transport, is responsible for estimating the transport, diffusion and deposition of radionuclides released to the atmosphere. This report discusses modeling transport and diffusion in the atmospheric pathway. It is divided into three major sections. The first section of the report presents the atmospheric modeling approach selected following discussion with the Technical Steering Panel that directs the HEDR Project. In addition, the section discusses the selection of the MESOI/MESORAD suite of atmospheric dispersion models that form the basis for initial calculations and future model development. The second section of the report describes alternative modeling approaches that were considered. Emphasis is placed on the family of plume and puff models that are based on Gaussian solution to the diffusion equations. The final portion of the section describes the performance of various models. The third section of the report discusses factors that bear on the selection of an atmospheric transport modeling approach for HEDR. These factors, which include the physical setting of the Hanford Site and the available meteorological data, serve as constraints on model selection. Five appendices are included in the report. 39 refs., 4 figs., 2 tabs.

Ramsdell, J.V.

1991-07-01T23:59:59.000Z

103

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.

104

Optimization models for improving periodic maintenance schedules by utilizing opportunities  

E-Print Network [OSTI]

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

Patriksson, Michael

105

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

SciTech Connect (OSTI)

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

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

106

Simulation Models for Improved Water Heating Systems  

E-Print Network [OSTI]

Storage Water Heater .point for modeling storage water heaters. The algorithmsfired, natural draft storage water heater. Figure 1 shows a

Lutz, Jim

2014-01-01T23:59:59.000Z

107

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

108

E-Print Network 3.0 - atmosphere-wildland fire model Sample Search...  

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

Computer Technologies and Information Sciences 6 A wildland fire model with data assimilation Jan Mandel ,a,b Summary: is to build a real-time coupled atmospheric-wildland fire...

109

E-Print Network 3.0 - atmosphere box model Sample Search Results  

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

Ecology 6 Investigating Large-scale Contemporary CO2 Sources and Sinks Using Inverse Transport Modelling Applied to CO2, CH4 and CO Summary: in atmospheric CO2 concentration. 3....

110

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

111

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 earth’s surface as variations in air pressure, their simulations in current coupled global climate models have not been fully examined. This ...

Covey, Curt

112

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

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

113

Improved computer models support genetics research  

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

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

114

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

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

AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE:1 First Use of Energy for All Purposes (Fuel and Nonfuel),Feet) Year Jan Feb Mar Apr MayAtmospheric Optical Depth (AOD)ProductssondeadjustsondeadjustAbout theOFFICEAmesApplication2ArgonneAssemblyDemandPlasma4

115

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

116

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

SciTech Connect (OSTI)

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

117

Introducing an Absolute Cavity Pyrgeometer (ACP) for Improving the Atmospheric Longwave Irradiance Measurement (Poster)  

SciTech Connect (OSTI)

Advancing climate change research requires accurate and traceable measurement of the atmospheric longwave irradiance. Current measurement capabilities are limited to an estimated uncertainty of larger than +/- 4 W/m2 using the interim World Infrared Standard Group (WISG). WISG is traceable to the Systeme international d'unites (SI) through blackbody calibrations. An Absolute Cavity Pyrgeometer (ACP) is being developed to measure absolute outdoor longwave irradiance with traceability to SI using the temperature scale (ITS-90) and the sky as the reference source, instead of a blackbody. The ACP was designed by NREL and optically characterized by the National Institute of Standards and Technology (NIST). Under clear-sky and stable conditions, the responsivity of the ACP is determined by lowering the temperature of the cavity and calculating the rate of change of the thermopile output voltage versus the changing net irradiance. The absolute atmospheric longwave irradiance is then calculated with an uncertainty of +/- 3.96 W/m2 with traceability to SI. The measured irradiance by the ACP was compared with the irradiance measured by two pyrgeometers calibrated by the World Radiation Center with traceability to the WISG.

Reda, I.; Stoffel, T.

2012-03-01T23:59:59.000Z

118

Visualizing Storms from NCAR's Atmosphere Model at NERSC  

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

AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE:1 First Use of Energy for All Purposes (Fuel and Nonfuel),Feet) Year Jan Feb Mar Apr May JunDatastreamsmmcrcalgovInstrumentsrucLasDelivered energy consumption by sectorlongUpdatesValley winsVideoVisitorTransportAtmosphere

119

On the Sensitivity of Atmospheric Model Implied Ocean Heat Transport to the Dominant Terms of the Surface Energy Balance  

SciTech Connect (OSTI)

The oceanic meridional heat transport (T{sub o}) implied by an atmospheric General Circulation Model (GCM) can help evaluate a model's readiness for coupling with an ocean GCM. In this study we examine the T{sub o} from benchmark experiments of the Atmospheric Model Intercomparison Project, and evaluate the sensitivity of T{sub o} to the dominant terms of the surface energy balance. The implied global ocean TO in the Southern Hemisphere of many models is equatorward, contrary to most observationally-based estimates. By constructing a hybrid (model corrected by observations) T{sub o}, an earlier study demonstrated that the implied heat transport is critically sensitive to the simulated shortwave cloud radiative effects, which have been argued to be principally responsible for the Southern Hemisphere problem. Systematic evaluation of one model in a later study suggested that the implied T{sub o} could be equally as sensitive to a model's ocean surface latent heat flux. In this study we revisit the problem with more recent simulations, making use of estimates of ocean surface fluxes to construct two additional hybrid calculations. The results of the present study demonstrate that indeed the implied T{sub o} of an atmospheric model is very sensitive to problems in not only the surface net shortwave, but the latent heat flux as well. Many models underestimate the shortwave radiation reaching the surface in the low latitudes, and overestimate the latent heat flux in the same region. The additional hybrid transport calculations introduced here could become useful model diagnostic tests as estimates of implied ocean surface fluxes are improved.

Gleckler, P J

2004-11-03T23:59:59.000Z

120

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

SciTech Connect (OSTI)

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

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

Simulation Models for Improved Water Heating Systems  

E-Print Network [OSTI]

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

Lutz, Jim

2014-01-01T23:59:59.000Z

122

An improved model for multiple effect distillation  

E-Print Network [OSTI]

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

Mistry, Karan H.

123

A PHYSICALLY-BASED SCHEME FOR THE URBAN ENERGY BUDGET IN ATMOSPHERIC MODELS  

E-Print Network [OSTI]

A PHYSICALLY-BASED SCHEME FOR THE URBAN ENERGY BUDGET IN ATMOSPHERIC MODELS VALÉRY MASSON Centre published data. Firstly, it is shown that the evolution of the model-predicted fluxes during a night. These two validations show that the radiative energy input to the urban surface model is realistic

Ribes, Aurélien

124

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

SciTech Connect (OSTI)

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

125

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

126

Fuel Cell System Improvement for Model-Based Diagnosis Analysis  

E-Print Network [OSTI]

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

Paris-Sud XI, Université de

127

Sparse optimization for inverse problems in atmospheric modelling  

E-Print Network [OSTI]

Apr 13, 2015 ... In S.-E. Gryning and F. Schiermeier, editors, Air Pollution Modeling and Its Application. XI, volume 21 of NATO Challenges of Modern Society, ...

2015-04-13T23:59:59.000Z

128

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

129

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.

130

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

131

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

132

Sensitivity of an Ocean-Atmosphere Coupled Model to the Coupling Method : Study of Tropical Cyclone  

E-Print Network [OSTI]

Sensitivity of an Ocean-Atmosphere Coupled Model to the Coupling Method : Study of Tropical Cyclone) in a realistic configuration aiming at simulating the genesis and propagation of tropical cyclone Erica and Oceanic Coupled Models (AOCMs) which account for important air-sea feedbacks. Separate integrations

Recanati, Catherine

133

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

E-Print Network [OSTI]

MEASUREMENT 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 waste storage and treatment lagoon in NC using a dynamic emission flux chamber. Results of model

Aneja, Viney P.

134

The impact of methane thermodynamics on seasonal convection and circulation in a model Titan atmosphere  

E-Print Network [OSTI]

The impact of methane thermodynamics on seasonal convection and circulation in a model Titan mechanisms controlling the distribution of methane convection and large-scale circulation in a simplified, axisymmetric model atmosphere of Titan forced by gray radiation and moist (methane) con- vection. The large

Caballero, Rodrigo

135

Improvements to the SHDOM Radiative Transfer Modeling Package  

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

AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE:1 First Use of Energy for All Purposes (Fuel and Nonfuel),Feet) Year Jan Feb Mar Apr MayAtmospheric Optical Depth7-1D: Vegetation ProposedUsingFun withconfinementEtching.348 270 300 219Improvements to the SHDOM Radiative

136

MODELING ATMOSPHERIC RELEASES OF TRITIUM FROM NUCLEAR INSTALLATIONS  

SciTech Connect (OSTI)

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

137

A Flexible Atmospheric Modeling Framework for the CESM  

SciTech Connect (OSTI)

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

138

Air pollution forecasting by coupled atmosphere-fire model WRF and SFIRE with WRF-Chem  

E-Print Network [OSTI]

Atmospheric pollution regulations have emerged as a dominant obstacle to prescribed burns. Thus, forecasting the pollution caused by wildland fires has acquired high importance. WRF and SFIRE model wildland fire spread in a two-way interaction with the atmosphere. The surface heat flux from the fire causes strong updrafts, which in turn change the winds and affect the fire spread. Fire emissions, estimated from the burning organic matter, are inserted in every time step into WRF-Chem tracers at the lowest atmospheric layer. The buoyancy caused by the fire then naturally simulates plume dynamics, and the chemical transport in WRF-Chem provides a forecast of the pollution spread. We discuss the choice of wood burning models and compatible chemical transport models in WRF-Chem, and demonstrate the results on case studies.

Kochanski, Adam K; Mandel, Jan; Clements, Craig B

2013-01-01T23:59:59.000Z

139

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

SciTech Connect (OSTI)

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

140

Improved Formulations for Air-Surface Exchanges Related to National Security Needs: Dry Deposition Models  

SciTech Connect (OSTI)

The Department of Homeland Security and others rely on results from atmospheric dispersion models for threat evaluation, event management, and post-event analyses. The ability to simulate dry deposition rates is a crucial part of our emergency preparedness capabilities. Deposited materials pose potential hazards from radioactive shine, inhalation, and ingestion pathways. A reliable characterization of these potential exposures is critical for management and mitigation of these hazards. A review of the current status of dry deposition formulations used in these atmospheric dispersion models was conducted. The formulations for dry deposition of particulate materials from am event such as a radiological attack involving a Radiological Detonation Device (RDD) is considered. The results of this effort are applicable to current emergency preparedness capabilities such as are deployed in the Interagency Modeling and Atmospheric Assessment Center (IMAAC), other similar national/regional emergency response systems, and standalone emergency response models. The review concludes that dry deposition formulations need to consider the full range of particle sizes including: 1) the accumulation mode range (0.1 to 1 micron diameter) and its minimum in deposition velocity, 2) smaller particles (less than .01 micron diameter) deposited mainly by molecular diffusion, 3) 10 to 50 micron diameter particles deposited mainly by impaction and gravitational settling, and 4) larger particles (greater than 100 micron diameter) deposited mainly by gravitational settling. The effects of the local turbulence intensity, particle characteristics, and surface element properties must also be addressed in the formulations. Specific areas for improvements in the dry deposition formulations are 1) capability of simulating near-field dry deposition patterns, 2) capability of addressing the full range of potential particle properties, 3) incorporation of particle surface retention/rebound processes, and. 4) development of dry deposition formulations applicable to urban areas. Also to improve dry deposition modeling capabilities, atmospheric dispersion models in which the dry deposition formulations are imbedded need better source-term plume initialization and improved in-plume treatment of particle growth processes. Dry deposition formulations used in current models are largely inapplicable to the complex urban environment. An improved capability is urgently needed to provide surface-specific information to assess local exposure hazard levels in both urban and non-urban areas on roads, buildings, crops, rivers, etc. A model improvement plan is developed with a near-term and far-term component. Despite some conceptual limitations, the current formulations for particle deposition based on a resistance approach have proven to provide reasonable dry deposition simulations. For many models with inadequate dry deposition formulations, adding or improving a resistance approach will be the desirable near-term update. Resistance models however are inapplicable aerodynamically very rough surfaces such as urban areas. In the longer term an improved parameterization of dry deposition needs to be developed that will be applicable to all surfaces, and in particular urban surfaces.

Droppo, James G.

2006-07-01T23:59:59.000Z

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.


141

Does increasing model stratospheric resolution improve extended range forecast skill?  

E-Print Network [OSTI]

Does increasing model stratospheric resolution improve extended range forecast skill? Greg Roff,1 forecast skill at high Southern latitudes is explored. Ensemble forecasts are made for two model configurations that differ only in vertical resolution above 100 hPa. An ensemble of twelve 30day forecasts

142

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

143

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.

144

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

145

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

146

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

147

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 model’s ability to simulate PAHs with different volatilities, ...

Friedman, Carey

148

Found: The missing blue opacity in atmosphere models of cool hydrogen white dwarfs  

E-Print Network [OSTI]

We investigate the importance of the far red wing of the Lyman $ \\alpha$ line of hydrogen in the atmospheres of cool white dwarfs of pure hydrogen composition. We find that this absorption process dominates all important sources of opacity in the blue part of the optical spectrum of these stars. Our successful fits to the spectra of cool DA/DC white dwarfs indicate that the far red wing of the $\\rm Ly \\alpha$ line is the source of opacity that had been missing in the models. The observed sequence of cool white dwarfs in color-color diagrams is very well reproduced by our new pure hydrogen atmosphere models, suggesting that the atmospheric composition of the coolest DC white dwarfs must be revisited.

P. M. Kowalski; D. Saumon

2006-09-26T23:59:59.000Z

149

The dynamics of a low-order coupled ocean-atmosphere model  

E-Print Network [OSTI]

A system of five ordinary differential equations is studied which combines the Lorenz-84 model for the atmosphere and a box model for the ocean. The behaviour of this system is studied as a function of the coupling parameters. For most parameter values, the dynamics of the atmosphere model is dominant. For a range of parameter values, competing attractors exist. The Kaplan-Yorke dimension and the correlation dimension of the chaotic attractor are numerically calculated and compared to the values found in the uncoupled Lorenz model. In the transition from periodic behaviour to chaos intermittency is observed. The intermittent behaviour occurs near a Neimark-Sacker bifurcation at which a periodic solution loses its stability. The length of the periodic intervals is governed by the time scale of the ocean component. Thus, in this regime the ocean model has a considerable influence on the dynamics of the coupled system.

L. van Veen; F. Verhulst; T. Opsteegh

1998-12-16T23:59:59.000Z

150

Demonstrating the improvement of predictive maturity of a computational model  

SciTech Connect (OSTI)

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

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

2010-01-01T23:59:59.000Z

151

Three Dimensional Adaptive Mesh Refinement on a Spherical Shell for Atmospheric Models with Lagrangian Coordinates  

E-Print Network [OSTI]

Three Dimensional Adaptive Mesh Refinement on a Spherical Shell for Atmospheric Models blocks and splits a block as refinements occur. The current functionality provides automatic generation the use of a longer time step. We have developed an Adaptive Mesh Refinement (AMR) dynamical core

Jablonowski, Christiane

152

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

153

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

154

Idealized test cases for the dynamical cores of Atmospheric General Circulation Models  

E-Print Network [OSTI]

Idealized test cases for the dynamical cores of Atmospheric General Circulation Models: A proposal) Ram Nair (NCAR) Mark Taylor (Sandia National Laboratory) May/29/2008 1 Idealized test cases for 3D dynamical cores This document describes the idealized dynamical core test cases that are proposed

Jablonowski, Christiane

155

Sensitivity of Ocean-Atmosphere Coupled Models to the Coupling Method : Example of Tropical Cyclone  

E-Print Network [OSTI]

Sensitivity of Ocean-Atmosphere Coupled Models to the Coupling Method : Example of Tropical Cyclone and propagation of tropical cyclone Erica. Sensitiv- ity tests to the coupling method are carried out-sea feedbacks. Separate integrations of the Corresponding author. Phone: +33 (0)4 76 51 48 60 Fax: +33 (0)4 76

156

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

157

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 over the last decades. Initiatives such as Lean Construction and Prefabrication have emerged in the construction industry to reduce the cost of house production and thereby the cost of the house itself

Paris-Sud XI, Université de

158

Description and validation of ERAD: An atmospheric dispersion model for high explosive detonations  

SciTech Connect (OSTI)

The Explosive Release Atmospheric Dispersion (ERAD) model is a three-dimensional numerical simulation of turbulent atmospheric transport and diffusion. An integral plume rise technique is used to provide a description of the physical and thermodynamic properties of the cloud of warm gases formed when the explosive detonates. Particle dispersion is treated as a stochastic process which is simulated using a discrete time Lagrangian Monte Carlo method. The stochastic process approach permits a more fundamental treatment of buoyancy effects, calm winds and spatial variations in meteorological conditions. Computational requirements of the three-dimensional simulation are substantially reduced by using a conceptualization in which each Monte Carlo particle represents a small puff that spreads according to a Gaussian law in the horizontal directions. ERAD was evaluated against dosage and deposition measurements obtained during Operation Roller Coaster. The predicted contour areas average within about 50% of the observations. The validation results confirm the model`s representation of the physical processes.

Boughton, B.A.; DeLaurentis, J.M.

1992-10-01T23:59:59.000Z

159

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

160

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

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

RSL: A parallel Runtime System Library for regional atmospheric models with nesting  

SciTech Connect (OSTI)

RSL is a parallel runtime system library developed at Argonne National Laboratory that is tailored to regular-grid atmospheric models with mesh refinement in the form of two-way interacting nested grids. RSL provides high-level stencil and interdomain communication, irregular domain decomposition, automatic local/global index translation, distributed I/O, and dynamic load balancing. RSL was used with Fortran90 to parallelize a well-known and widely used regional weather model, the Penn State/NCAR Mesoscale model.

Michalakes, J.G.

1997-08-01T23:59:59.000Z

162

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

SciTech Connect (OSTI)

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

163

Monitoring and ANN modeling of coal stockpile behavior under different atmospheric conditions  

SciTech Connect (OSTI)

In this study, an industrial-sized stockpile of 5 m width, 4 m height, and 10 m length was built in a coal stock area to investigate coal stockpile behavior under different atmospheric conditions. The effective parameters on the coal stockpile that were time, weather temperature, atmospheric pressure, air humidity, velocity, and direction of wind values were automatically measured by means of a computer-aided measurement system to obtain Artificial Neural Network (ANN) input data. The coal stockpiles, which should be continuously observed, are capable of spontaneous combustion and then causing serious economical losses due to the mentioned parameters. Afterwards, these measurement values were used for training and testing of the ANN model. Comparison of the experimental and ANN results, accuracy rates of training, and testing were found as 98.6% and 98.7%, respectively. It is shown that possible coal stockpile behavior with this ANN model is powerfully estimated.

Ozdeniz, A.H.; Ozbay, Y.; Yilmaz, N.; Sensogut, C. [Selcuk University, Konya (Turkey). Engineering & Architecture Faculty

2008-07-01T23:59:59.000Z

164

Atmospheric transmission model for a solar beam propagating between a heliostat and a receiver  

SciTech Connect (OSTI)

Formulae are presented that provide estimates of the transmittance for a solar beam propagating between a heliostat and a central receiver. These formulae are wavelength independent, functional fits to the tabulated data of Vittitoe and Biggs, which in turn are from numerical integrations of spectral transmittance data calculated with the aid of the computer code LOWTRAN 3. The formulae allow for interpolation and extrapolation, and they have a form characteristic of atmospheric transmission models. The transmittance model contains five explicit physical variables (the site elevation H, the atmospheric water vapor density rho, the scattering coefficient ..beta.., the tower height h, and the slant range R) and three implicit variables (the season of the year, the climatic region, and the site elevation H) because rho and ..beta.. are dependent on these three variables.

Pitman, C.L.; Vant-Hull, L.L.

1982-01-01T23:59:59.000Z

165

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

166

A Model of Intra-seasonal Oscillations in the Earth atmosphere  

E-Print Network [OSTI]

We suggest a way of rationalizing an intra-seasonal oscillations (IOs) of the Earth atmospheric flow as four meteorological relevant triads of interacting planetary waves, isolated from the system of all the rest planetary waves. Our model is independent of the topography (mountains, etc.) and gives a natural explanation of IOs both in the North and South 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; Victor S. L'vov

2007-04-04T23:59:59.000Z

167

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

SciTech Connect (OSTI)

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

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

2014-09-08T23:59:59.000Z

168

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

SciTech Connect (OSTI)

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

169

IMPROVING PREDICTIONS OF CLIMATE CHANGE: OBSERVATIONAL AND MODELING REQUIREMENTS  

E-Print Network [OSTI]

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

170

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

E-Print Network [OSTI]

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

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

2013-01-01T23:59:59.000Z

171

Summary of the March 25--26, 1991 atmospheric model working meeting. Hanford Environmental Dose Reconstruction Project  

SciTech Connect (OSTI)

Atmospheric transport and diffusion calculations for the initial phase of the Hanford Environmental Dose Reconstruction (HEDR) Project were made using the MESOILT2 computer code (Ramsdell and Burk 1991). This code implemented a Lagrangian trajectory, puff dispersion model using components from other models designed primarily for regulatory applications. Uncertainty in the dispersion calculations was estimated following model calculations. The results of the atmospheric dispersion calculations were summarized in frequency distributions by location for use in preliminary dose calculations.

Ramsdell, J.V.

1992-07-01T23:59:59.000Z

172

An Improved Probabilistic Fracture Mechanics Model for Pressurized Thermal Shock  

SciTech Connect (OSTI)

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

Dickson, T.L.

2001-10-29T23:59:59.000Z

173

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

SciTech Connect (OSTI)

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

174

Modeling dust as component minerals in the Community Atmosphere Model: development of framework and impact on radiative forcing  

SciTech Connect (OSTI)

The mineralogy of desert dust is important due to its effect on radiation, clouds and biogeochemical cycling of trace nutrients. This study presents the simulation of dust radiative forcing as a function of both mineral composition and size at the global scale using mineral soil maps for estimating emissions. Externally mixed mineral aerosols in the bulk aerosol module in the Community Atmosphere Model version 4 (CAM4) and internally mixed mineral aerosols in the modal aerosol module in the Community Atmosphere Model version 5.1 (CAM5) embedded in the Community Earth System Model version 1.0.5 (CESM) are speciated into common mineral components in place of total dust. The simulations with mineralogy are compared to available observations of mineral atmospheric distribution and deposition along with observations of clear-sky radiative forcing efficiency. Based on these simulations, we estimate the all-sky direct radiative forcing at the top of the atmosphere as +0.05Wm?2 for both CAM4 and CAM5 simulations with mineralogy and compare this both with simulations of dust in release versions of CAM4 and CAM5 (+0.08 and +0.17Wm?2) and of dust with optimized optical properties, wet scavenging and particle size distribution in CAM4 and CAM5, ?0.05 and ?0.17Wm?2, respectively. The ability to correctly include the mineralogy of dust in climate models is hindered by its spatial and temporal variability as well as insufficient global in-situ observations, incomplete and uncertain source mineralogies and the uncertainties associated with data retrieved from remote sensing methods.

Scanza, Rachel; Mahowald, N.; Ghan, Steven J.; Zender, C. S.; Kok, J. F.; Liu, Xiaohong; Zhang, Y.; Albani, Samuel

2015-01-01T23:59:59.000Z

175

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

176

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

177

Testing the atmospheric dispersion model of CSA N288.1 with site-specific data  

E-Print Network [OSTI]

The atmospheric dispersion component of CSA Standard N288. 1, which provides guidelines for calculating derived release limits, has been tested. Long-term average concentrations of tritium in air were predicted using site-specific release rates and meteorological data and compared with measured concentrations at 43 monitoring sites at all CANDU stations in Canada. The predictions correlate well with the observations but were found to be conservative, overestimating by about 50% on average. The model overpredicted 84% of the time, with the highest prediction lying a factor of 5.5 above the corresponding observation. The model underpredicted the remaining 16% of the time, with the lowest prediction about one-half of the corresponding measurement. Possible explanations for this bias are discussed but no single reason appears capable of accounting for the discrepancy. Rather, the tendency to overprediction seems to result from the cumulative effects of a number of small conservatisms in the model. The model predi...

Chouhan, S L

2001-01-01T23:59:59.000Z

178

A Three-Dimensional Ocean-Seaice-Carbon Cycle Model and its Coupling to a Two-Dimensional Atmospheric Model: Uses in Climate Change Studies  

E-Print Network [OSTI]

We describe the coupling of a three-dimensional ocean circulation model, with explicit thermodynamic seaice and ocean carbon cycle representations, to a two-dimensional atmospheric/land model. This coupled system has been ...

Dutkiewicz, Stephanie.

179

VALDRIFT 1.0: A valley atmospheric dispersion model with deposition  

SciTech Connect (OSTI)

VALDRIFT version 1.0 is an atmospheric transport and diffusion model for use in well-defined mountain valleys. It is designed to determine the extent of ddft from aedal pesticide spraying activities, but can also be applied to estimate the transport and diffusion of various air pollutants in valleys. The model is phenomenological -- that is, the dominant meteorological processes goveming the behavior of the valley atmosphere are formulated explicitly in the model, albeit in a highly parameterized fashion. The key meteorological processes treated are: (1) nonsteady and nonhomogeneous along-valley winds and turbulent diffusivities, (2) convective boundary layer growth, (3) inversion descent, (4) noctumal temperature inversion breakup, and (5) subsidence. The model is applicable under relatively cloud-free, undisturbed synoptic conditions and is configured to operate through one diumal cycle for a single valley. The inputs required are the valley topographical characteristics, pesticide release rate as a function of time and space, along-valley wind speed as a function of time and space, temperature inversion characteristics at sunrise, and sensible heat flux as a function of time following sunrise. Default values are provided for certain inputs in the absence of detailed observations. The outputs are three-dimensional air concentration and ground-level deposition fields as a function of time.

Allwine, K.J.; Bian, X.; Whiteman, C.D.

1995-05-01T23:59:59.000Z

180

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

SciTech Connect (OSTI)

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

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

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

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

or distribute Atmospheric and Geologic Sources of Mercury Kejimkujik Park has no direct industrial... is atmospheric deposition. The global ... Source: O'Driscoll, Nelson -...

182

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

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

183

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

184

Atmospheric transmittance model for a solar beam propagating between a heliostat and a receiver  

SciTech Connect (OSTI)

This report presents formulae that provide reliable estimates of the percent energy loss P/sub L/ (or, equivalently, the transmittance tau) of a solar beam propagating between a heliostat and a receiver. These formulae are wavelength-independent, functional fits to the tabulated results of Vittitoe and Biggs, which in turn are the results of numerical integrations of spectral transmittance data calculated with the aid of the computer code LOWTRAN 3. The formulae allow for interpolation and extrapolation and have a form characteristic of atmospheric transmittance models.

Pitman, C.L.; Vant-Hull, L.L.

1984-02-01T23:59:59.000Z

185

Flooding Experiments and Modeling for Improved Reactor Safety  

SciTech Connect (OSTI)

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

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

2008-09-14T23:59:59.000Z

186

Predictive Fallout Composition Modeling: Improvements and Applications of the Defense Land Fallout Interpretive Code  

SciTech Connect (OSTI)

This paper outlines several improvements to the Particle Activity Module of the Defense Land Fallout Interpretive Code (DELFIC). The modeling of each phase of the fallout process is discussed within DELFIC to demonstrate the capabilities and limitations with the code for modeling and simulation. Expansion of the DELFIC isotopic library to include actinides and light elements is shown. Several key features of the new library are demonstrated, including compliance with ENDF/B-VII standards, augmentation of hardwired activated soil and actinide decay calculations with exact Bateman calculations, and full physical and chemical fractionation of all material inventories. Improvements to the radionuclide source term are demonstrated, including the ability to specify heterogeneous fission types and the ability to import source terms from irradiation calculations using the Oak Ridge Isotope Generation (ORIGEN) code. Additionally, the dose, kerma, and effective dose conversion factors are revised. Finally, the application of DELFIC for consequence management planning and forensic analysis is presented. For consequence management, DELFIC is shown to provide disaster recovery teams with simulations of real-time events, including the location, composition, time of arrival, activity rates, and dose rates of fallout, accounting for site-specific atmospheric effects. The results from DELFIC are also demonstrated for use by nuclear forensics teams to plan collection routes (including the determination of optimal collection locations), estimate dose rates to collectors, and anticipate the composition of material at collection sites. These capabilities give mission planners the ability to maximize their effectiveness in the field while minimizing risk to their collectors.

Hooper, David A [ORNL; Jodoin, Vincent J [ORNL; Lee, Ronald W [ORNL; Monterial, Mateusz [ORNL

2012-01-01T23:59:59.000Z

187

Posters Single-Column Model for Atmospheric Radiation Measurement Sites: Model  

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

AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE:1 First Use of Energy for All Purposes (Fuel and Nonfuel),Feet) Year Jan Feb Mar Apr MayAtmosphericNuclear Security Administration the1 - September 2006PhotovoltaicSeptember 22, 2014SocietyJ. Dudhia51 Posters75517733

188

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

SciTech Connect (OSTI)

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

189

DOE research on atmospheric aerosols  

SciTech Connect (OSTI)

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

190

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

SciTech Connect (OSTI)

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

191

ISO-SWS calibration and the accurate modelling of cool-star atmospheres - II. General results  

E-Print Network [OSTI]

The fine calibration of the ISO-SWS detectors (Infrared Space Observatory - Short Wavelength Spectrometer) has proven to be a delicate problem. We therefore present a detailed spectroscopic study in the 2.38 -- 12 micron wavelength range of a sample of 16 A0 -- M2 stars used for the calibration of ISO-SWS. By investigating the discrepancies between the ISO-SWS data of these sources, the theoretical predictions of their spectra, the high-resolution FTS-KP (Kitt Peak) spectrum of Alpha Boo and the solar FTS-ATMOS (Atmospheric Trace Molecule Spectroscopy) spectrum, both calibration problems and problems in computing the theoretical models and the synthetic spectra are revealed. The underlying reasons for these problems are sought for and the impact on the further calibration of ISO-SWS and on the theoretical modelling is discussed extensively.

L. Decin; B. Vandenbussche; C. Waelkens; K. Eriksson; B. Gustafsson; B. Plez; A. J. Sauval; K. Hinkle

2002-07-29T23:59:59.000Z

192

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

SciTech Connect (OSTI)

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

193

An experimental set-up to apply polarization modulation to infrared reflection absorption spectroscopy for improved in situ studies of atmospheric corrosion processes  

SciTech Connect (OSTI)

A new set-up for improved monitoring of atmospheric corrosion processes in situ and in real-time is presented. To characterize chemical structures of thin films on metal surfaces surface sensitive analytical techniques are required. One possible technique is Infrared Reflection Absorption Spectroscopy (IRRAS) which has become an established method to investigate surface corrosion films of thicknesses less than 200 nm. However, there are limitations related to the sensitivity of these measurements, in case of investigating ultrathin films or absorption bands of interest, surface species are superimposed by atmospheric background absorption, which changes during in situ measurements in ambient atmospheres. These difficulties of in situ surface reflection measurements can be eliminated by availing the polarization selectivity of adsorbed surface species. At grazing angles of incidence the absorption of p-polarized infrared radiation by thin surface films on metals is enhanced, while the absorption of s-polarized light by this film is nearly zero. This different behavior of the polarization properties leads to strong selection rules at the surface and can therefore be used to identify molecules adsorbed on metal surfaces. Polarization Modulation (PM) of the infrared (IR) light takes advantage of this disparity of polarization on sample surfaces and in combination with IRRAS yielding a very sensitive and surface-selective method for obtaining IR spectra of ultra-thin films on metal surfaces. An already existing in situ IRRAS/Quartz Crystal Microbalance weathering cell was combined with PM and evaluated according to its applicability to study in situ atmospheric corrosion processes. First real-time measurements on silver samples exposed to different atmospheres were performed showing the advantage of PM-IRRAS compared to conventional IRRAS for such investigations.

Wiesinger, R. [Institute of Science and Technology in Art, Academy of Fine Arts, 1010 Vienna (Austria); Schade, U. [Helmholtz-Zentrum für Materialien und Energy GmbH, Elektronenspeicherring BESSY II, 12489 Berlin (Germany); Kleber, Ch. [Centre for Electrochemical Surface Technology, 2700 Wiener Neustadt (Austria); Schreiner, M. [Institute of Science and Technology in Art, Academy of Fine Arts, 1010 Vienna (Austria); Institute for Chemical Technologies and Analytics, Vienna University of Technology, 1060 Vienna (Austria)

2014-06-15T23:59:59.000Z

194

COUNTERCURRENT FLOW LIMITATION EXPERIMENTS AND MODELING FOR IMPROVED REACTOR SAFETY  

SciTech Connect (OSTI)

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

195

HGSYSTEMUF6. Model for Simulating Dispersion due to Atmospheric Release of UF6  

SciTech Connect (OSTI)

HGSYSTEMUF6 is a suite of models designed for use in estimating consequences associated with accidental, atmospheric release of Uranium Hexafluoride (UF6) and its reaction products, namely Hydrogen Fluoride (HF), and other non-reactive contaminants which are either negatively, neutrally, or positively buoyant. It is based on HGSYSTEM Version 3.0 of Shell Research LTD., and contains specific algorithms for the treatment of UF6 chemistry and thermodynamics. HGSYSTEMUF6 contains algorithms for the treatment of dense gases, dry and wet deposition, effects due to the presence of buildings (canyon and wake), plume lift-off, and the effects of complex terrain. The models components of the suite include (1) AEROPLUME/RK, used to model near-field dispersion from pressurized two-phase jet releases of UF6 and its reaction products, (2) HEGADAS/UF6 for simulating dense, ground based release of UF6, (3) PGPLUME for simulation of passive, neutrally buoyant plumes (4) UF6Mixer for modeling warm, potentially reactive, ground-level releases of UF6 from buildings, and (5) WAKE, used to model elevated and ground-level releases into building wake cavities of non-reactive plumes that are either neutrally or positively buoyant.

Hanna, G [George Mason University, (United States); Chang, J.C. [Earthtech, Inc., (United States); Zhang, J.X. [BlazeTech Corporation, (United States); Bloom, S.G. [Lockheed Martin Energy Systems, Oak Ridge, TN (United States); Goode, W.D. Jr [Bechtel Jacobs Company, Oak Ridge, TN (United States); Lombardi, D.A. [JBF Associates, (United States); Yambert, M.W. [LMERC, Oak Ridge, TN (United States)

1998-08-01T23:59:59.000Z

196

Improvements in Hanford TRU Program Utilizing Systems Modeling and Analyses  

SciTech Connect (OSTI)

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

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

2008-07-01T23:59:59.000Z

197

A hydrodynamic model for asymmetric explosions of rapidly rotating collapsing supernovae with a toroidal atmosphere  

E-Print Network [OSTI]

We numerically solved the two-dimensional axisymmetric hydrodynamic problem of the explosion of a low-mass neutron star in a circular orbit. In the initial conditions, we assumed a nonuniform density distribution in the space surrounding the collapsed iron core in the form of a stationary toroidal atmosphere that was previously predicted analytically and computed numerically. The con?guration of the exploded neutron star itself was modeled by a torus with a circular cross section whose central line almost coincided with its circular orbit. Using an equation of state for the stellar matter and the toroidal atmosphere in which the nuclear statistical equilibrium conditions were satisfied, we performed a series of numerical calculations that showed the propagation of a strong divergent shock wave with a total energy of 0.2x10^51 erg at initial explosion energy release of 1.0x10^51 erg. In our calculations, we rigorously took into account the gravitational interaction, including the attraction from a higher-mass (1.9M_solar) neutron star located at the coordinate origin, in accordance with the rotational explosion mechanism for collapsing supernovae.W e compared in detail our results with previous similar results of asymmetric supernova explosion simulations and concluded that we found a lower limit for the total explosion energy.

V. S. Imshennik; K. V. Manukovskii

2004-11-16T23:59:59.000Z

198

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

199

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

E-Print Network [OSTI]

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

Reif, Rafael

200

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

SciTech Connect (OSTI)

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

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

Comparison of Atmospheric Water Vapor in Observational and Model Data Sets  

SciTech Connect (OSTI)

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

202

SUPERBURST MODELS FOR NEUTRON STARS WITH HYDROGEN- AND HELIUM-RICH ATMOSPHERES  

SciTech Connect (OSTI)

Superbursts are rare day-long type I X-ray bursts due to carbon flashes on accreting neutron stars in low-mass X-ray binaries. They heat the neutron star envelope such that the burning of accreted hydrogen and helium becomes stable, and the common shorter X-ray bursts are quenched. Short bursts reappear only after the envelope cools down. We study multi-zone one-dimensional models of the neutron star envelope, in which we follow carbon burning during the superburst, and we include hydrogen and helium burning in the atmosphere above. We investigate the cases of both a solar-composition and a helium-rich atmosphere. This allows us to study for the first time a wide variety of thermonuclear burning behavior as well as the transitions between the different regimes in a self-consistent manner. For solar composition, burst quenching ends much sooner than previously expected. This is because of the complex interplay between the 3{alpha}, hot CNO, and CNO breakout reactions. Stable burning of hydrogen and helium transitions via marginally stable burning (mHz quasi-periodic oscillations) to less energetic bursts with short recurrence times. We find a short-lived bursting mode where weaker and stronger bursts alternate. Eventually the bursting behavior changes back to that of the pre-superburst bursts. Because of the scarcity of observations, this transition has not been directly detected after a superburst. Using the MINBAR burst catalog we identify the shortest upper limit on the quenching time for 4U 1636-536, and derive further constraints on the timescale on which bursts return.

Keek, L. [National Superconducting Cyclotron Laboratory, Department of Physics and Astronomy, and Joint Institute for Nuclear Astrophysics, Michigan State University, East Lansing, MI 48824 (United States); Heger, A. [School of Physics and Astronomy, University of Minnesota, 116 Church Street SE, Minneapolis, MN 55455 (United States); In 't Zand, J. J. M., E-mail: keek@nscl.msu.edu [SRON Netherlands Institute for Space Research, Sorbonnelaan 2, 3584 CA Utrecht (Netherlands)

2012-06-20T23:59:59.000Z

203

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

204

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

SciTech Connect (OSTI)

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

205

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.

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

2014-12-01T23:59:59.000Z

206

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

207

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-JĂĽrgen

208

Improved Space Charge Modeling for Simulation and Design of Photoinjectors  

SciTech Connect (OSTI)

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

209

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 (OSTI)

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

210

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

E-Print Network [OSTI]

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

Dunlop, Mary

2012-01-01T23:59:59.000Z

211

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.

212

ORNL researchers improve soil carbon cycling models | ornl.gov  

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

AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE:1 First Use of Energy for All Purposes (Fuel and Nonfuel),Feet) Year Jan Feb Mar Apr MayAtmosphericNuclear Security Administration the ContributionsArms Control R&DNuclearNuclearCamilaOak

213

Sandia National Laboratories: improving PV performance model accuracy  

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

AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE:1 First Use of Energy for All Purposes (Fuel and Nonfuel),Feet) Year Jan Feb Mar Apr MayAtmosphericNuclear Security Administration the1developmentturbine blade manufacturing the viability of U.S.-based

214

Sandia National Laboratories: improving PV performance model technical  

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

AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE:1 First Use of Energy for All Purposes (Fuel and Nonfuel),Feet) Year Jan Feb Mar Apr MayAtmosphericNuclear Security Administration the1developmentturbine blade manufacturing the viability of U.S.-basedrigor

215

DUSTRAN 1.0 User’s Guide: A GIS-Based Atmospheric Dust Dispersion Modeling System  

SciTech Connect (OSTI)

The U.S. Department of Energy’s Pacific Northwest National Laboratory just completed a multi-year project to develop a fully tested and documented atmospheric dispersion modeling system (DUST TRANsport or DUSTRAN) to assist the U.S. Department of Defense in addressing particulate air quality issues at military training and testing ranges. This manual documents the DUSTRAN modeling system and includes installation instructions, a user’s guide, and detailed example tutorials.

Allwine, K Jerry; Rutz, Frederick C.; Shaw, William J.; Rishel, Jeremy P.; Fritz, Brad G.; Chapman, Elaine G.; Hoopes, Bonnie L.; Seiple, Timothy E.

2006-09-22T23:59:59.000Z

216

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

217

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

E-Print Network [OSTI]

In order to provide improved predictions of Pellet Cladding Mechanical Interaction (PCMI) for the FRAPCON nuclear fuel performance code, a new model, the FRAPCON Radial-Axial Soft Pellet (FRASP) model, was developed. This ...

Mieloszyk, Alexander James

2012-01-01T23:59:59.000Z

218

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

SciTech Connect (OSTI)

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

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

2013-05-20T23:59:59.000Z

219

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

220

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

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

Atmospheric Model Ocean Model  

E-Print Network [OSTI]

-Seasonal Prediction of Remote Drivers of Australian Climate Variability using POAMA Andrew G Marshall, Debbie Hudson index at 140°°°°E for OBS and POAMA hindcasts > http://poama.bom.gov.au andrew.marshall@bom.gov.au #12;

Marshall, Andrew

222

Continuous-time model reference adaptive control with improved transient performance  

E-Print Network [OSTI]

. . 10 3. 1. Introduction . . 3. 2. Performance of a Standard MRAC Scheme. . . . . . . . . 3. 3. Performance Improvement as Input Disturbance Rejection 3. 4. A Modified MRAC Scheme for Improved Transient Per- formance . 3. 5. Example and Simulations... 10 13 16 21 24 IV MODEL REFERENCE ADAPTIVE CONTROL OF RIGID ROBOTS WITH IMPROVED TRANSIENT PERFORMANCE 27 4. 1. Introduction 4. 2. Performance of a Standard MRAC Scheme for a Robotic Manipulator . 4. 3. Performance Improvement as Input...

Ho, Ming-Tzu

1993-01-01T23:59:59.000Z

223

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

224

Improving week two forecasts with multi-model re-forecast ensembles  

E-Print Network [OSTI]

Improving week two forecasts with multi-model re-forecast ensembles Jeffrey S. Whitaker and Xue Wei NOAA-CIRES Climate Diagnostics Center, Boulder, CO Fr´ed´eric Vitart Seasonal Forecasting Group, ECMWF dataset of ensemble 're-forecasts' from a single model can significantly improve the skill

Whitaker, Jeffrey S.

225

Atmospheric Carbon Dioxide Variability in the Community Earth System Model: Evaluation and Transient Dynamics during the Twentieth and Twenty-First Centuries  

E-Print Network [OSTI]

Atmospheric Carbon Dioxide Variability in the Community Earth System Model: Evaluation pathways (RCPs 4.5 and 8.5) using the Community Earth System Model­Biogeochemistry (CESM1- BGC). CO2

Hoffman, Forrest M.

226

Improving Air-Conditioner and Heat Pump Modeling (Presentation)  

SciTech Connect (OSTI)

A new approach to modeling residential air conditioners and heat pumps allows users to model systems by specifying only the more readily-available SEER/EER/HSPF-type metrics. Manufacturer data was used to generate full sets of model inputs for over 450 heat pumps and air conditioners. A sensitivity analysis identified which inputs can be safely defaulted 'behind-the-scenes' without negatively impacting the reliability of energy simulations.

Winkler, J.

2012-03-01T23:59:59.000Z

227

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

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

the development of next generation electric-drive vehicle batteries," NREL Energy Storage Group Manager Ahmad Pesaran said. "By adding this model to their software package,...

228

Data Collection for Improved Cold Temperature Thermal Modeling...  

Broader source: Energy.gov (indexed) [DOE]

be generalized to other temperatures - Methodology uses response surface and empirical data-fitting techniques - Techniques result in simplified general models Cold Ambient...

229

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

E-Print Network [OSTI]

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

230

The solar photospheric abundance of hafnium and thorium. Results from CO5BOLD 3D hydrodynamic model atmospheres  

E-Print Network [OSTI]

Context: The stable element hafnium (Hf) and the radioactive element thorium (Th) were recently suggested as a suitable pair for radioactive dating of stars. The applicability of this elemental pair needs to be established for stellar spectroscopy. Aims: We aim at a spectroscopic determination of the abundance of Hf and Th in the solar photosphere based on a \\cobold 3D hydrodynamical model atmosphere. We put this into a wider context by investigating 3D abundance corrections for a set of G- and F-type dwarfs. Method: High-resolution, high signal-to-noise solar spectra were compared to line synthesis calculations performed on a solar CO5BOLD model. For the other atmospheres, we compared synthetic spectra of CO5BOLD 3D and associated 1D models. Results: For Hf we find a photospheric abundance A(Hf)=0.87+-0.04, in good agreement with a previous analysis, based on 1D model atmospheres. The weak Th ii 401.9 nm line constitutes the only Th abundance indicator available in the solar spectrum. It lies in the red wing of an Ni-Fe blend exhibiting a non-negligible convective asymmetry. Accounting for the asymmetry-related additional absorption, we obtain A(Th)=0.09+-0.03, consistent with the meteoritic abundance, and about 0.1 dex lower than obtained in previous photospheric abundance determinations. Conclusions: Only for the second time, to our knowledge, has am non-negligible effect of convective line asymmetries on an abundance derivation been highlighted. Three-dimensional hydrodynamical simulations should be employed to measure Th abundances in dwarfs if similar blending is present, as in the solar case. In contrast, 3D effects on Hf abundances are small in G- to mid F-type dwarfs and sub-giants, and 1D model atmospheres can be conveniently used.

Elisabetta Caffau; L. Sbordone; H. -G. Ludwig; P. Bonifacio; M. Steffen; N. T. Behara

2008-03-25T23:59:59.000Z

231

[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

232

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

233

Increasing NOAA's computational capacity to improve global forecast modeling  

E-Print Network [OSTI]

Systems Division Stephen J. Lord Director, NWS NCEP Environmental Modeling Center 19 July 2010 (303) 4973060 tom.hamill@noaa.gov #12; 2 Executive Summary The accuracy of many

Hamill, Tom

234

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

E-Print Network [OSTI]

forests indi- cates that the model representation of competition between plants and microbes for new mineral nitrogen resources is reasonable. Our results suggest a weaker dependence of net land carbon flux on soil moisture changes in tropical regions... National Laboratory, Oak Ridge, TN 37831-6335, USA 2Department of Marine Chemistry and Geochemistry, Woods Hole Oceanographic Institution, Woods Hole, MA 02543-1543, USA 3Climate and Global Dynamics Division, National Center for Atmospheric Research...

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

235

Advanced Measurement and Modeling Techniques for Improved SOFC Cathodes  

SciTech Connect (OSTI)

The goal of this project was to develop an improved understanding of factors governing performance and degradation of mixed-conducting SOFC cathodes. Two new diagnostic tools were developed to help achieve this goal: (1) microelectrode half-cells for improved isolation of cathode impedance on thin electrolytes, and (2) nonlinear electrochemical impedance spectroscopy (NLEIS), a variant of traditional impedance that allows workers to probe nonlinear rates as a function of frequency. After reporting on the development and efficacy of these tools, this document reports on the use of these and other tools to better understand performance and degradation of cathodes based on the mixed conductor La{sub 1-x}Sr{sub x}CoO{sub 3-{delta}} (LSC) on gadolinia or samaria-doped ceria (GDC or SDC). We describe the use of NLEIS to measure O{sub 2} exchange on thin-film LSC electrodes, and show that O{sub 2} exchange is most likely governed by dissociative adsorption. We also describe parametric studies of porous LSC electrodes using impedance and NLEIS. Our results suggest that O{sub 2} exchange and ion transport co-limit performance under most relevant conditions, but it is O{sub 2} exchange that is most sensitive to processing, and subject to the greatest degradation and sample-to-sample variation. We recommend further work that focuses on electrodes of well-defined or characterized geometry, and probes the details of surface structure, composition, and impurities. Parallel work on primarily electronic conductors (LSM) would also be of benefit to developers, and to improved understanding of surface vs. bulk diffusion.

Stuart Adler; L. Dunyushkina; S. Huff; Y. Lu; J. Wilson

2006-12-31T23:59:59.000Z

236

Benchmark experiments with global climate models applicable to extra-solar gas giant planets in the shallow atmosphere approximation  

E-Print Network [OSTI]

The growing field of exoplanetary atmospheric modelling has seen little work on standardised benchmark tests for its models, limiting understanding of the dependence of results on specific models and conditions. With spatially resolved observations as yet difficult to obtain, such a test is invaluable. Although an intercomparison test for models of tidally locked gas giant planets has previously been suggested and carried out, the data provided were limited in terms of comparability. Here, the shallow PUMA model is subjected to such a test, and detailed statistics produced to facilitate comparison, with both time means and the associated standard deviations displayed, removing the time dependence and providing a measure of the variability. Model runs have been analysed to determine the variability between resolutions, and the effect of resolution on the energy spectra studied. Superrotation is a robust and reproducible feature at all resolutions.

Bending, V L; Kolb, U

2012-01-01T23:59:59.000Z

237

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

SciTech Connect (OSTI)

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 6.8×1014 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 1.2×1016 to 2.5×1016 Bq and estimates for the facility in Indonesia vary from 6.1×1013 to 3.6×1014 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

238

Data Collection for Improved Cold Temperature Thermal Modeling | Department  

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

AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page on Google Bookmark EERE: Alternative Fuels Data Center Home Page on Delicious Rank EERE:YearRound-UpHeat Pump Models | Department1 Prepared by:DTE Energy VideoDarkof Energy Modeling

239

The Tropical Atmospheric El Nio Signal in Satellite Precipitation Data and a Global Climate Model  

E-Print Network [OSTI]

) ABSTRACT Aspects of the tropical atmospheric response to El Niño related to the global energy and water and the Advanced Micro- wave Scanning Radiometer-E and simulations from the Goddard Institute for Space Studies are highly correlated, but anomalies in stratiform­convective rainfall partitioning in the two datasets

240

Can a more realistic model error structure improve the parameter estimation in modelling the dynamics of sh populations?  

E-Print Network [OSTI]

or applying an estimation method that is robust to the error structure assumption in modelling the dynamicsCan a more realistic model error structure improve the parameter estimation in modelling the dynamics of ®sh populations? Y. Chena,* , J.E. Paloheimob a Fisheries Conservation Chair Program, Fisheries

Chen, Yong

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

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 forsimu- lations from 15 Earth System Models (ESMs) • Most ESMsdioxide biases in Earth System Models, J. Geophys. Res.

2014-01-01T23:59:59.000Z

242

OUMBE, Armel, WALD, Lucien, BLANC, Philippe, and SCHROEDTER-HOMSCHEIDT, Marion. Exploitation of radiative transfer model for assessing solar radiation: the relative importance of atmospheric  

E-Print Network [OSTI]

of radiative transfer model for assessing solar radiation: the relative importance of atmospheric constituents, Germany * Corresponding Author, armel.oumbe@ensmp.fr Abstract Solar radiation is modified in its way: solar radiation, atmospheric optics, satellite images, Heliosat method 1. Introduction A wealth

Paris-Sud XI, Université de

243

Improved Economic Operation of MSWC Plants with a New Model Based PID Control Strategy  

E-Print Network [OSTI]

Improved Economic Operation of MSWC Plants with a New Model Based PID Control Strategy M. Leskens the performance of the MSWC plant combustion control system, which typically is of the PID-type. In this paper models. More specific, from a closer analysis of the dynamics of these models a new PID-type of MSWC

Van den Hof, Paul

244

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 RĂ©union - 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

245

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

246

Improvements to Nuclear Data and Its Uncertainties by Theoretical Modeling  

SciTech Connect (OSTI)

This project addresses three important gaps in existing evaluated nuclear data libraries that represent a significant hindrance against highly advanced modeling and simulation capabilities for the Advanced Fuel Cycle Initiative (AFCI). This project will: Develop advanced theoretical tools to compute prompt fission neutrons and gamma-ray characteristics well beyond average spectra and multiplicity, and produce new evaluated files of U and Pu isotopes, along with some minor actinides; Perform state-of-the-art fission cross-section modeling and calculations using global and microscopic model input parameters, leading to truly predictive fission cross-sections capabilities. Consistent calculations for a suite of Pu isotopes will be performed; Implement innovative data assimilation tools, which will reflect the nuclear data evaluation process much more accurately, and lead to a new generation of uncertainty quantification files. New covariance matrices will be obtained for Pu isotopes and compared to existing ones. The deployment of a fleet of safe and efficient advanced reactors that minimize radiotoxic waste and are proliferation-resistant is a clear and ambitious goal of AFCI. While in the past the design, construction and operation of a reactor were supported through empirical trials, this new phase in nuclear energy production is expected to rely heavily on advanced modeling and simulation capabilities. To be truly successful, a program for advanced simulations of innovative reactors will have to develop advanced multi-physics capabilities, to be run on massively parallel super- computers, and to incorporate adequate and precise underlying physics. And all these areas have to be developed simultaneously to achieve those ambitious goals. Of particular interest are reliable fission cross-section uncertainty estimates (including important correlations) and evaluations of prompt fission neutrons and gamma-ray spectra and uncertainties.

Danon, Yaron; Nazarewicz, Witold; Talou, Patrick

2013-02-18T23:59:59.000Z

247

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

248

Dark Stars: Improved Models and First Pulsation Results  

E-Print Network [OSTI]

We use the stellar evolution code MESA to study dark stars. Dark stars (DSs), which are powered by dark matter (DM) self-annihilation rather than by nuclear fusion, may be the first stars to form in the Universe. We compute stellar models for accreting DSs with masses up to 10^6 M_{sun}. The heating due to DM annihilation is self-consistently included, assuming extended adiabatic contraction of DM within the minihalos in which DSs form. We find remarkably good overall agreement with previous models, which assumed polytropic interiors. There are some differences in the details, with positive implications for observability. We found that, in the mass range of 10^4 -10^5 M_{sun}, our DSs are hotter by a factor of 1.5 than those in Freese et al.(2010), are smaller in radius by a factor of 0.6, denser by a factor of 3 - 4, and more luminous by a factor of 2. Our models also confirm previous results, according to which supermassive DSs are very well approximated by (n=3)-polytropes. We also perform a first study of dark star pulsations. Our DS models have pulsation modes with timescales ranging from less than a day to more than two years in their rest frames, at z ~ 15, depending on DM particle mass and overtone number. Such pulsations may someday be used to identify bright, cool objects uniquely as DSs; if properly calibrated, they might, in principle, also supply novel standard candles for cosmological studies.

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

2015-01-12T23:59:59.000Z

249

Data Collection for Improved Cold Temperature Thermal Modeling and Strategy  

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

AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page on Google Bookmark EERE: Alternative Fuels Data Center Home Page on Delicious Rank EERE:YearRound-UpHeat Pump Models | Department1 Prepared by:DTE Energy VideoDark

250

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

251

Development of an atmospheric aerosol model for studies of global budgets and effects of airborne particulate material  

SciTech Connect (OSTI)

A microphysics-removal Atmospheric Aerosol Model (AAM) is developed for use in General Circulation Models (GCM) to study global budgets and effects of particulate material. In this model the particle population is assumed to be composed of a set of log-normal modes whose time evolution due to microphysical processes is described via prognostic equations for an appropriate number of moments of the particle size distribution. This newly devised technique, by making use of a small number of prognostic equations for the aerosol variables and utilizing optimized numerical procedures, renders the model computationally efficient, hence particularly suitable for use in complex 3D GCMs. Detailed parameterizations of particle coagulation, sedimentation, dry deposition, and wet removal are incorporated into the AAM.

Giorgi, F.

1986-01-01T23:59:59.000Z

252

Improved user interface design for site selection modeling system  

SciTech Connect (OSTI)

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

253

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.

254

RESIDUA UPGRADING EFFICIENCY IMPROVEMENT MODELS: COKE FORMATION PREDICTABILITY MAPS  

SciTech Connect (OSTI)

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

255

An improved model for the transit entropy of monatomic liquids  

SciTech Connect (OSTI)

In the original formulation of V-T theory for monatomic liquid dynamics, the transit contribution to entropy was taken to be a universal constant, calibrated to the constant-volume entropy of melting. This model suffers two deficiencies: (a) it does not account for experimental entropy differences of {+-}2% among elemental liquids, and (b) it implies a value of zero for the transit contribution to internal energy. The purpose of this paper is to correct these deficiencies. To this end, the V-T equation for entropy is fitted to an overall accuracy of {+-}0.1% to the available experimental high temperature entropy data for elemental liquids. The theory contains two nuclear motion contributions: (a) the dominant vibrational contribution S{sub vib}(T/{theta}{sub 0}), where T is temperature and {theta}{sub 0} is the vibrational characteristic temperature, and (b) the transit contribution S{sub tr}(T/{theta}{sub tr}), where {theta}{sub tr} is a scaling temperature for each liquid. The appearance of a common functional form of S{sub tr} for all the liquids studied is a property of the experimental data, when analyzed via the V-T formula. The resulting S{sub tr} implies the correct transit contribution to internal energy. The theoretical entropy of melting is derived, in a single formula applying to normal and anomalous melting alike. An ab initio calculation of {theta}{sub 0}, based on density functional theory, is reported for liquid Na and Cu. Comparison of these calculations with the above analysis of experimental entropy data provides verification of V-T theory. In view of the present results, techniques currently being applied in ab initio simulations of liquid properties can be employed to advantage in the further testing and development of V-T theory.

Wallace, Duane C [Los Alamos National Laboratory; Chisolm, Eric D [Los Alamos National Laboratory; Bock, Nicolas [Los Alamos National Laboratory

2009-01-01T23:59:59.000Z

256

Modelled Black Carbon Radiative Forcing and Atmospheric Lifetime in AeroCom Phase II Constrained by Aircraft Observations  

SciTech Connect (OSTI)

Black carbon (BC) aerosols absorb solar radiation, and are generally held to exacerbate global warming through exerting a positive radiative forcing1. However, the total contribution of BC to the ongoing changes in global climate is presently under debate2-8. Both anthropogenic BC emissions and the resulting spatial and temporal distribution of BC concentration are highly uncertain2,9. In particular, long range transport and processes affecting BC atmospheric lifetime are poorly understood, leading to large estimated uncertainty in BC concentration at high altitudes and far from emission sources10. These uncertainties limit our ability to quantify both the historical, present and future anthropogenic climate impact of BC. Here we compare vertical profiles of BC concentration from four recent aircraft measurement campaigns with 13 state of the art aerosol models, and show that recent assessments may have overestimated present day BC radiative forcing. Further, an atmospheric lifetime of BC of less than 5 days is shown to be essential for reproducing observations in transport dominated remote regions. Adjusting model results to measurements in remote regions, and at high altitudes, leads to a 25% reduction in the multi-model median direct BC forcing from fossil fuel and biofuel burning over the industrial era.

Samset, B. H.; Myhre, G.; Herber, Andreas; Kondo, Yutaka; Li, Shao-Meng; Moteki, N.; Koike, Makoto; Oshima, N.; Schwarz, Joshua P.; Balkanski, Y.; Bauer, S.; Bellouin, N.; Berntsen, T.; Bian, Huisheng; Chin, M.; Diehl, Thomas; Easter, Richard C.; Ghan, Steven J.; Iversen, T.; Kirkevag, A.; Lamarque, Jean-Francois; Lin, Guang; Liu, Xiaohong; Penner, Joyce E.; Schulz, M.; Seland, O.; Skeie, R. B.; Stier, P.; Takemura, T.; Tsigaridis, Kostas; Zhang, Kai

2014-11-27T23:59:59.000Z

257

Development of an atmospheric aerosol model for studies of global budgets and effects of airborne particulate material  

SciTech Connect (OSTI)

A microphysics-removal atmospheric aerosol model (AAM) is developed for use in general circulation models (GCMs) to study global budgets and effects of particulate material. In this model the particle population is composed of a set of log-normal modes whose time evolution due to microphysical processes is described via prognostic equations for an appropriate number of moments of the particle-size distribution. Detailed parameterizations of particle coagulation, sedimentation, dry deposition, and wet removal are developed and implemented into the AAM. The AAM is incorporated into a GCM and is applied to two types of studies: (1) characteristics of the particle wet and dry removal processes, and (2) climatic impact of massive particulate injections following a global nuclear war, with emphasis on the sensitivity of the simulated effects to the inclusion of particle microphysics. Results are discussed.

Giorgi, F.

1986-01-01T23:59:59.000Z

258

Final Technical Report: Development of the DUSTRAN GIS-Based Complex Terrain Model for Atmospheric Dust Dispersion  

SciTech Connect (OSTI)

Activities at U.S. Department of Defense (DoD) training and testing ranges can be sources of dust in local and regional airsheds governed by air-quality regulations. The U.S. Department of Energy’s Pacific Northwest National Laboratory just completed a multi-year project to develop a fully tested and documented atmospheric dispersion modeling system (DUST TRANsport or DUSTRAN) to assist the DoD in addressing particulate air-quality issues at military training and testing ranges.

Allwine, K Jerry; Rutz, Frederick C.; Shaw, William J.; Rishel, Jeremy P.; Fritz, Brad G.; Chapman, Elaine G.; Hoopes, Bonnie L.; Seiple, Timothy E.

2007-05-01T23:59:59.000Z

259

A study of atmosphere-ocean interaction using a one-dimensional numerical air-sea boundary layer model  

E-Print Network [OSTI]

surface with no allowance for exchange induced by wave action. The model does produce reasonable solutions, in comparison with oceanic data, for the response of the lower atmosphere and the upper ocean to specific. sets of meteorological and oceanic.../2 this function is of the form f(Ri) = (1 + b Ri) , then one obtains ? 3 1/2 2 -1 K (z) = K 62 (gX ) exp(z/W) (z/I + rdI) (1 + b Ri) hw 1 (61) Although KITAIGORODSKII (1961) does not give a specific value of b, it would appear that b = 10/3 would be in line...

Hebenstreit, Gerald Thomas

1974-01-01T23:59:59.000Z

260

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.

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

Droplet Number Prediction in the NCAR Community Atmosphere Model Steven Ghan Pacific Northwest National Laboratory  

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

AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE:1 First Use of Energy for All Purposes (Fuel and Nonfuel),Feet) Year Jan Feb Mar Apr MayAtmospheric Optical Depth7-1D: Vegetation Proposed Newcatalyst phasesDataTranslocationDiurnalCommittee Draftfor $1.14 Per

262

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

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

AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE:1 First Use of Energy for All Purposes (Fuel and Nonfuel),Feet) Year Jan Feb Mar Apr MayAtmosphericNuclear Security Administration the1 - SeptemberMicroneedles for medical point ofPowerSaverPredicting The

263

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

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

AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE:1 First Use of Energy for All Purposes (Fuel and Nonfuel),Feet) Year Jan Feb Mar Apr MayAtmospheric Optical Depth (AOD)ProductssondeadjustsondeadjustAbout theOFFICEAmes Laboratory Site| Department ofAn InsideAn Update|Update

264

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

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

AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE:1 First Use of Energy for All Purposes (Fuel and Nonfuel),Feet) Year Jan Feb Mar Apr MayAtmosphericNuclear Security Administrationcontroller systemsBi (2)Sharing Smart GridShiftMethodSimwYpes(tm)Single microbeC.J.AC.

265

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

SciTech Connect (OSTI)

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

266

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

267

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

268

Improved Swing-Cut Modeling for Planning and Scheduling of Oil-Refinery Distillation Units  

E-Print Network [OSTI]

, Pennsylvania 15213, United States. Crude-oil assays, Distillation, Fractionation, Swing-cuts, Temperature cut with in the nonlinear optimization. 1. INTRODUCTION Distillation or fractionation models for planning and scheduling1 Improved Swing-Cut Modeling for Planning and Scheduling of Oil-Refinery Distillation Units Brenno

Grossmann, Ignacio E.

269

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

270

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

271

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

SciTech Connect (OSTI)

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

272

Coupling of a regional atmospheric model (RegCM3) and a regional oceanic model (FVCOM) over the maritime continent  

E-Print Network [OSTI]

Climatological high resolution coupled climate model simulations for the maritime continent have been carried out using the regional climate model (RegCM) version 3 and the finite volume coastal ocean model (FVCOM) ...

Wei, Jun

273

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

274

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

275

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

SciTech Connect (OSTI)

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

Seppanen, Olli; Fisk, William J.

2003-06-01T23:59:59.000Z

276

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

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

277

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

SciTech Connect (OSTI)

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

278

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

279

A grid of MARCS model atmospheres for late-type stars I. Methods and general properties  

E-Print Network [OSTI]

We have constructed a grid of about 10,000 spherically symmetric and plane-parallel models with the MARCS program, and make it available for public use. Parameter ranges are: Teff=2500 to 8000 K, log g =log(GM/R2)= -1 to 5 (cgs) with various masses and radii, [Me/H]=-5 to +1, with [Alpha/Fe] = 0.0 and 0.4 and different choices of C and N abundances to also represent stars of types R, S and N, and with microturbulence parameters from 1 to 5 km/s. We also list fluxes in approximately 108,000 wavelength points. Underlying assumptions in addition to 1D stratification include hydrostatic equilibrium, MLT convection and LTE. A number of general properties of the models are discussed, in relation to the effects of changing blanketing and sphericity. Models are compared with other available grids and excellent agreement is found with plane-parallel models of Castelli and Kurucz within the overlapping parameter range. Although there are departures from the spherically symmetric NextGen models, the agreement with more recent PHOENIX models is gratifying. The models of the grid show regularities, but some interesting departures from general patterns occur for the coolest models due to the molecular opacities. We have tested rules of thumb concerning effects of blanketing and sphericity and found them to often be astonishingly accurate. Some interesting new phenomena have been discovered, such as the intricate coupling between blanketing and sphericity, and the strong effects of carbon enhancement on metal-poor models. We give further details of models and comparisons with observations in subsequent papers.

Bengt Gustafsson; Bengt Edvardsson; Kjell Eriksson; Uffe Graae Jorgensen; Aake Nordlund; Bertrand Plez

2008-05-05T23:59:59.000Z

280

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

SciTech Connect (OSTI)

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

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

Improvement of capabilities of the Distributed Electrochemistry Modeling Tool for investigating SOFC long term performance  

SciTech Connect (OSTI)

This report provides an overview of the work performed for Solid Oxide Fuel Cell (SOFC) modeling during the 2012 Winter/Spring Science Undergraduate Laboratory Internship at Pacific Northwest National Laboratory (PNNL). A brief introduction on the concept, operation basics and applications of fuel cells is given for the general audience. Further details are given regarding the modifications and improvements of the Distributed Electrochemistry (DEC) Modeling tool developed by PNNL engineers to model SOFC long term performance. Within this analysis, a literature review on anode degradation mechanisms is explained and future plans of implementing these into the DEC modeling tool are also proposed.

Gonzalez Galdamez, Rinaldo A.; Recknagle, Kurtis P.

2012-04-30T23:59:59.000Z

282

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

SciTech Connect (OSTI)

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

283

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

SciTech Connect (OSTI)

An improved gas-damping model for the out-of-plane motion of a near-substrate microbeam is developed based on the Reynolds equation (RE). A boundary condition for the RE is developed that relates the pressure at the beam edge to the beam motion. The coefficients in this boundary condition are determined from Navier-Stokes slip-jump (NSSJ) simulations for small slip lengths (relative to the gap height) and from direct simulation Monte Carlo (DSMC) molecular gas dynamics simulations for larger slip lengths. This boundary condition significantly improves the accuracy of the RE when the microbeam width is only slightly greater than the gap height between the microbeam and the substrate. The improved RE model is applied to microbeams fabricated using the SUMMiT V process.

Gallis, Michail A.; Torczynski, John Robert

2003-09-01T23:59:59.000Z

284

Asian Tracer Experiment and Atmospheric Modeling (TEAM) Project: Draft Field Work Plan for the Asian Long-Range Tracer Experiment  

SciTech Connect (OSTI)

This report provides an experimental plan for a proposed Asian long-range tracer study as part of the international Tracer Experiment and Atmospheric Modeling (TEAM) Project. The TEAM partners are China, Japan, South Korea and the United States. Optimal times of year to conduct the study, meteorological measurements needed, proposed tracer release locations, proposed tracer sampling locations and the proposed durations of tracer releases and subsequent sampling are given. Also given are the activities necessary to prepare for the study and the schedule for completing the preparation activities leading to conducting the actual field operations. This report is intended to provide the TEAM members with the information necessary for planning and conducting the Asian long-range tracer study. The experimental plan is proposed, at this time, to describe the efforts necessary to conduct the Asian long-range tracer study, and the plan will undoubtedly be revised and refined as the planning goes forward over the next year.

Allwine, K Jerry; Flaherty, Julia E.

2007-08-01T23:59:59.000Z

285

Pluto's Atmosphere Does Not Collapse  

E-Print Network [OSTI]

Combining stellar occultation observations probing Pluto's atmosphere from 1988 to 2013 and models of energy balance between Pluto's surface and atmosphere, we conclude that Pluto's atmosphere does not collapse at any point in its 248-year orbit. The occultation results show an increasing atmospheric pressure with time in the current epoch, a trend present only in models with a high thermal inertia and a permanent N2 ice cap at Pluto's north rotational pole.

Olkin, C B; Borncamp, D; Pickles, A; Sicardy, B; Assafin, M; Bianco, F B; Buie, M W; de Oliveira, A Dias; Gillon, M; French, R G; Gomes, A Ramos; Jehin, E; Morales, N; Opitom, C; Ortiz, J L; Maury, A; Norbury, M; Ribas, F B; Smith, R; Wasserman, L H; Young, E F; Zacharias, M; Zacharias, N

2013-01-01T23:59:59.000Z

286

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

287

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

288

"How Can Earth Observation Data Be Implemented To Improve Parameterisation of Carbon Models"  

E-Print Network [OSTI]

"How Can Earth Observation Data Be Implemented To Improve Parameterisation of Carbon Models practices, afforestation and reforestation. The quantification of the strength of carbon uptake by forests is therefore important if we intend to offset emissions by the management of forests for sequestration. Current

289

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.

290

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

291

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.

292

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

293

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

294

A Hierarchical Bayesian Model for Improving Short-Term Forecasting of Hospital Demand by Including Meteorological  

E-Print Network [OSTI]

A Hierarchical Bayesian Model for Improving Short-Term Forecasting of Hospital Demand by Including Sarran4 Abstract The effect of weather on health has been widely researched, and the ability to forecast, better predictions of hospital demand that are more sensitive to fluctuations in weather can allow

Sahu, Sujit K

295

Resveratrol Improves Survival, Hemodynamics and Energetics in a Rat Model of Hypertension Leading to  

E-Print Network [OSTI]

Resveratrol Improves Survival, Hemodynamics and Energetics in a Rat Model of Hypertension Leading and vascular function as well as cardiac and skeletal muscle energy metabolism were assessed in a hypertensive/kg/day; HS-RSV) was given for 8 weeks after hypertension and cardiac hypertrophy were established (which

Paris-Sud XI, Université de

296

USING TIME-LAPSE SEISMIC MEASUREMENTS TO IMPROVE FLOW MODELING OF CO2 INJECTION  

E-Print Network [OSTI]

Marly. The EOR process in the RCP section of the Weyburn Field uses CO2 and water injection to displaceUSING TIME-LAPSE SEISMIC MEASUREMENTS TO IMPROVE FLOW MODELING OF CO2 INJECTION IN THE WEYBURN, particularly CO2. Time lapse seismic monitoring has motivated changes to the reservoir description in a flow

297

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

E-Print Network [OSTI]

deficit in the near field, Proceedings of the European Wind Energy Conference, Madrid, Spain, European, Boundary Layer Meteorology 132, pp. 129-149, 2009. [3] G. Larsen, H. Madsen and N. Sørensen, Mean wake·Wake models are used to improve predictions of Annual Energy Production (AEP) of wind farms. ·Wake

Daraio, Chiara

298

PERFORMANCE OF A SPECTRAL ELEMENT ATMOSPHERIC MODEL SEAM ON THE HP EXEMPLAR SPP2000.  

E-Print Network [OSTI]

discretization strategy taken from NCAR's Community Climate Model Version 3 (CCM3) [9]. Spectral elements have avoiding clustering points at the poles. Secondly, by using a local coordinate system within each element Fournier for helpful comments. This work was supported in part by the U.S. Department of Energy; Oce

Baer, Ferdinand

299

BTRAM: An Interactive Atmospheric Radiative Transfer Model I.M. Chapman1  

E-Print Network [OSTI]

radiance incident on the spectrometer/radiometer. Computer simulations, known as radiative transfer models source of opacity at submillimetre wavelengths where many objects emit most of their energy. Although high altitude observatories (such as the James Clerk Maxwell Telescope (JCMT) in Hawaii and the Atacama

Naylor, David A.

300

Analytical and experimental investigations of gas turbine model combustor acoustics operated at atmospheric pressure  

E-Print Network [OSTI]

Analytical and experimental investigations of gas turbine model combustor acoustics operated the eigenmodes of the combustor results from the resonant coupling between pressure disturbances in the flame distribution within the combustor, except when these frequencies match. When the frequencies are close to each

Paris-Sud XI, Université de

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

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

SciTech Connect (OSTI)

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

302

Final Report for "Improved Representations of Cloud Microphysics for Model and Remote Sensing Evaluation using Data Collected during ISDAC, TWP-ICE and RACORO  

SciTech Connect (OSTI)

We were funded by ASR to use data collected during ISDAC and TWP-ICE to evaluate models with a variety of temporal and spatial scales, to evaluate 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. In particular, we proposed to: 1) Calculate distributions of microphysical properties observed in arctic stratus during ISDAC for initializing and evaluating LES and GCMs, and for developing parameterizations of effective particle sizes, mean fall velocities, and mean single-scattering properties for such models; 2) Improve representations of particle sizes, fall velocities and scattering properties for tropical and arctic cirrus using TWP-ICE, ISDAC and M-PACE data, and to determine the contributions that small ice crystals, with maximum dimensions D less than 50 ?m, make to mass and radiative properties; 3) Study fundamental interactions between clouds and radiation by improving representations of small quasi-spherical particles and their scattering properties. We were additionally funded 1-year by ASR to use RACORO data to develop an integrated product of cloud microphysical properties. We accomplished all of our goals.

McFarquhar, Greg M. [University of Illinois] University of Illinois

2003-06-11T23:59:59.000Z

303

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

SciTech Connect (OSTI)

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

304

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

SciTech Connect (OSTI)

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

305

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

306

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

E-Print Network [OSTI]

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

Shingledecker, Christopher N

2014-01-01T23:59:59.000Z

307

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

SciTech Connect (OSTI)

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

308

Self-consistent fluid modeling and simulation on a pulsed microwave atmospheric-pressure argon plasma jet  

SciTech Connect (OSTI)

In present study, a pulsed lower-power microwave-driven atmospheric-pressure argon plasma jet has been introduced with the type of coaxial transmission line resonator. The plasma jet plume is with room air temperature, even can be directly touched by human body without any hot harm. In order to study ionization process of the proposed plasma jet, a self-consistent hybrid fluid model is constructed in which Maxwell's equations are solved numerically by finite-difference time-domain method and a fluid model is used to study the characteristics of argon plasma evolution. With a Guass type input power function, the spatio-temporal distributions of the electron density, the electron temperature, the electric field, and the absorbed power density have been simulated, respectively. The simulation results suggest that the peak values of the electron temperature and the electric field are synchronous with the input pulsed microwave power but the maximum quantities of the electron density and the absorbed power density are lagged to the microwave power excitation. In addition, the pulsed plasma jet excited by the local enhanced electric field of surface plasmon polaritons should be the discharge mechanism of the proposed plasma jet.

Chen, Zhaoquan, E-mail: zqchen@aust.edu.cn [Faculty of Physics, St. Petersburg State University, St. Petersburg 198504 (Russian Federation); College of Electrical and Information Engineering, Anhui University of Science and Technology, Huainan, Anhui 232001 (China); Yin, Zhixiang, E-mail: zxyin66@163.com; Chen, Minggong; Hong, Lingli; Hu, Yelin; Huang, Yourui [College of Electrical and Information Engineering, Anhui University of Science and Technology, Huainan, Anhui 232001 (China); Xia, Guangqing; Liu, Minghai [State Key Laboratory of Advanced Electromagnetic Engineering and Technology, Huazhong University of Science and Technology, Wuhan, Hubei 430074 (China); Kudryavtsev, A. A. [Faculty of Physics, St. Petersburg State University, St. Petersburg 198504 (Russian Federation)

2014-10-21T23:59:59.000Z

309

Incorporation of crop phenology in Simple Biosphere Model (SiBcrop) to improve land-atmosphere carbon exchanges from croplands  

SciTech Connect (OSTI)

In the original paper a mistake in Figure 11 occurred. The corrected version of the figure is provided.

Lokupitiya, Erandathie; Denning, Scott; Paustian, Keith; Baker, Ian; Schaefer, Kevin; Verma, Shashi; Meyers, Tilden; Bernacchi, Carl; Suyker, Andrew; Fischer, Marc

2009-02-10T23:59:59.000Z

310

Scientific uncertainties in atmospheric mercury models III: Boundary and initial conditions, model grid resolution, and Hg(II) reduction mechanism  

SciTech Connect (OSTI)

In this study, the model response in terms of simulated mercury concentration and deposition to boundary condition (BC), initial condition (IC), model grid resolution (12 km versus 36 km), and two alternative Hg(II) reduction mechanisms, was investigated. The model response to the change of gaseous elemental mercury (GEM) concentration from 0 to 2 ngm3 in IC/BC is found to be very linear (r240.99) based on the results of sensitivity simulations in July 2001. An increase of 1 ngm3 of GEM in BC resulted in an increase of 0.81 ngm3 in the monthly average of total mercury concentration, and 1270 ngm2 in the monthly total deposition. IC has similar but weaker effects compared to those of BC. An increase of 1 ngm3 of GEM in IC resulted in an increase of 0.14 ngm3 in the monthly average of total mercury concentration, and 250 ngm2 in the monthly total deposition. Varying reactive gaseous mercury (RGM) or particulate mercury (PHg) in BC/IC has much less significant impact. Simulation results at different grid resolutions show good agreement (slope 0.950 1.026, r 0.816 0.973) in mercury concentration, dry deposition, and total deposition. The agreement in wet deposition is somewhat weaker (slope 0.770 0.794, r 0.685 0.892) due to the difference in emission dilution and simulated precipitation that subsequently change reaction rates in the aqueous phase. Replacing the aqueous Hg(II)-HO2 reduction by either RGM reduction by CO (51018cm3 molecule1 s1) or photoreduction of RGM (1105 s1) gives significantly better model agreement with the wet deposition measured by Mercury Deposition Network (MDN). Possible ranges of the reduction rates are estimated based on model sensitivity results. The kinetic estimate requires further verification by laboratory studies.

Lin, Che-Jen [ORNL; Pongprueksa, Pruek [Lamar University; Lindberg, Steven Eric [ORNL; Jang, Carey [U.S. Environmental Protection Agency, Raleigh, North Carolina; Braverman, Thomas [U.S. Environmental Protection Agency, Raleigh, North Carolina; Bullock, Russell O [NOAA; Ho, Thomas [ORNL; Chu, Hsing-Wei [Lamar University

2008-03-01T23:59:59.000Z

311

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.

312

IMPROVED MODELING OF THE MASS DISTRIBUTION OF DISK GALAXIES BY THE EINASTO HALO MODEL  

SciTech Connect (OSTI)

Analysis of the rotation curves (RCs) of spiral galaxies provides an efficient diagnostic for studying the properties of dark matter halos and their relations with baryonic material. Since the cored pseudo-isothermal (Iso) model usually provides a better description of observed RCs than does the cuspy Navarro-Frenk-White (NFW) model, there have been concerns that the {Lambda}CDM primordial density fluctuation spectrum may not be the correct one. We have modeled the RCs of galaxies from The H I Nearby Galaxy Survey (THINGS) with the Einasto halo model, which has emerged as the best-fitting model of the halos arising in dissipationless cosmological N-body simulations. We find that the RCs are significantly better fit with the Einasto halo than with either Iso or NFW halo models. In our best-fit Einasto models, the radius of density slope -2 and the density at this radius are highly correlated. The Einasto index, which controls the overall shape of the density profile, is near unity on average for intermediate and low mass halos. This is not in agreement with the predictions from {Lambda}CDM simulations. The indices of the most massive halos are in rough agreement with those cosmological simulations and appear correlated with the halo virial mass. We find that a typical Einasto density profile declines more strongly in its outermost parts than any of the Iso or NFW models whereas it is relatively shallow in its innermost regions. The core nature of those regions of halos thus extends the cusp-core controversy found for the NFW model with low surface density galaxies to the Einasto halo with more massive galaxies like those of THINGS. The Einasto concentrations decrease as a function of halo mass, in agreement with trends seen in numerical simulations. However, they are generally smaller than values expected for simulated Einasto halos. We thus find that, so far, the Einasto halo model provides the best match to the observed RCs and can therefore be considered as a new standard model for dark matter halos.

Chemin, Laurent [Universite de Bordeaux, Observatoire Aquitain des Sciences de l'Univers, BP 89, 33271 Floirac Cedex (France); De Blok, W. J. G. [ACGC, Department of Astronomy, University of Cape Town, Rondebosch 7700 (South Africa); Mamon, Gary A., E-mail: chemin@obs.u-bordeaux1.fr, E-mail: edeblok@ast.uct.ac.za, E-mail: gam@iap.fr [Institut d'Astrophysique de Paris (UMR 7095: CNRS and UPMC), 98 bis Bd. Arago, 75014 Paris (France)

2011-10-15T23:59:59.000Z

313

Improved model for the analysis of air fluorescence induced by electrons  

E-Print Network [OSTI]

A model recently proposed for the calculation of air-fluorescence yield excited by electrons is revisited. Improved energy distributions of secondary electrons and a more realistic Monte Carlo simulation including some additional processes have allowed us to obtain more accurate results. The model is used to study in detail the relationship between fluorescence intensity and deposited energy in a wide range of primary energy (keVs - GeVs). In addition, predictions on the absolute value of the fluorescence efficiency in the absence of collisional quenching will be presented and compared with available experimental data.

F. Arqueros; F. Blanco; J. Rosado

2008-07-24T23:59:59.000Z

314

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

315

Refining climate models  

SciTech Connect (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

2012-10-31T23:59:59.000Z

316

32ND INTERNATIONAL COSMIC RAY CONFERENCE, BEIJING 2011 Numerical model of cosmic ray induced ionization in the atmosphere CRAC:CRII  

E-Print Network [OSTI]

¨a Geophysical Observatory, University of Oulu, Finland 2 Ioffe Physical-Technical Institute, St provided the energy spectrum of incoming cosmic rays is known. It computes the background ionization due this a new model we evaluate the ionization effects in the atmosphere caused by several major solar energetic

Mironova, Irina A.

317

Quantifying atmospheric pollution across north america from boreal forest fires: a combined analysis of atmospheric modelling and ground-based remote sensing   

E-Print Network [OSTI]

This paper describes the interpretation of the 2010 summer LIDAR observations from Dal- housie University, Nova Scotia. The GEOS-Chem global 3D chemistry transport model was used to identify the chemical and optical ...

Trigwell, Robert

2011-11-24T23:59:59.000Z

318

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

SciTech Connect (OSTI)

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

319

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

320

INTERNAL GRAVITY WAVES FROM ATMOSPHERIC JETS AND FRONTS  

E-Print Network [OSTI]

INTERNAL GRAVITY WAVES FROM ATMOSPHERIC JETS AND FRONTS Riwal Plougonven1 and Fuqing Zhang2 consistently highlighted jet exit regions as a favored locus for intense gravity waves, the mechanisms need for improving parameterizations of nonorographic gravity waves in climate models that include

Plougonven, Riwal

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

Incorporating Single-nucleotide Polymorphisms Into the Lyman Model to Improve Prediction of Radiation Pneumonitis  

SciTech Connect (OSTI)

Purpose: To determine whether single-nucleotide polymorphisms (SNPs) in genes associated with DNA repair, cell cycle, transforming growth factor-{beta}, tumor necrosis factor and receptor, folic acid metabolism, and angiogenesis can significantly improve the fit of the Lyman-Kutcher-Burman (LKB) normal-tissue complication probability (NTCP) model of radiation pneumonitis (RP) risk among patients with non-small cell lung cancer (NSCLC). Methods and Materials: Sixteen SNPs from 10 different genes (XRCC1, XRCC3, APEX1, MDM2, TGF{beta}, TNF{alpha}, TNFR, MTHFR, MTRR, and VEGF) were genotyped in 141 NSCLC patients treated with definitive radiation therapy, with or without chemotherapy. The LKB model was used to estimate the risk of severe (grade {>=}3) RP as a function of mean lung dose (MLD), with SNPs and patient smoking status incorporated into the model as dose-modifying factors. Multivariate analyses were performed by adding significant factors to the MLD model in a forward stepwise procedure, with significance assessed using the likelihood-ratio test. Bootstrap analyses were used to assess the reproducibility of results under variations in the data. Results: Five SNPs were selected for inclusion in the multivariate NTCP model based on MLD alone. SNPs associated with an increased risk of severe RP were in genes for TGF{beta}, VEGF, TNF{alpha}, XRCC1 and APEX1. With smoking status included in the multivariate model, the SNPs significantly associated with increased risk of RP were in genes for TGF{beta}, VEGF, and XRCC3. Bootstrap analyses selected a median of 4 SNPs per model fit, with the 6 genes listed above selected most often. Conclusions: This study provides evidence that SNPs can significantly improve the predictive ability of the Lyman MLD model. With a small number of SNPs, it was possible to distinguish cohorts with >50% risk vs <10% risk of RP when they were exposed to high MLDs.

Tucker, Susan L., E-mail: sltucker@mdanderson.org [Department of Bioinformatics and Computational Biology, University of Texas MD Anderson Cancer Center, Houston, Texas (United States); Li Minghuan [Department of Radiation Oncology, Shandong Cancer Hospital, Jinan, Shandong (China)] [Department of Radiation Oncology, Shandong Cancer Hospital, Jinan, Shandong (China); Xu Ting; Gomez, Daniel [Department of Radiation Oncology, University of Texas MD Anderson Cancer Center, Houston, Texas (United States)] [Department of Radiation Oncology, University of Texas MD Anderson Cancer Center, Houston, Texas (United States); Yuan Xianglin [Department of Oncology, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan (China)] [Department of Oncology, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan (China); Yu Jinming [Department of Radiation Oncology, Shandong Cancer Hospital, Jinan, Shandong (China)] [Department of Radiation Oncology, Shandong Cancer Hospital, Jinan, Shandong (China); Liu Zhensheng; Yin Ming; Guan Xiaoxiang; Wang Lie; Wei Qingyi [Department of Epidemiology, University of Texas MD Anderson Cancer Center, Houston, Texas (United States)] [Department of Epidemiology, University of Texas MD Anderson Cancer Center, Houston, Texas (United States); Mohan, Radhe [Department of Radiation Physics, University of Texas MD Anderson Cancer Center, Houston, Texas (United States)] [Department of Radiation Physics, University of Texas MD Anderson Cancer Center, Houston, Texas (United States); Vinogradskiy, Yevgeniy [University of Colorado School of Medicine, Aurora, Colorado (United States)] [University of Colorado School of Medicine, Aurora, Colorado (United States); Martel, Mary [Department of Radiation Physics, University of Texas MD Anderson Cancer Center, Houston, Texas (United States)] [Department of Radiation Physics, University of Texas MD Anderson Cancer Center, Houston, Texas (United States); Liao Zhongxing [Department of Radiation Oncology, University of Texas MD Anderson Cancer Center, Houston, Texas (United States)] [Department of Radiation Oncology, University of Texas MD Anderson Cancer Center, Houston, Texas (United States)

2013-01-01T23:59:59.000Z

322

An improved simple polarisable water model for use in biomolecular simulation  

SciTech Connect (OSTI)

The accuracy of biomolecular simulations depends to some degree on the accuracy of the water model used to solvate the biomolecules. Because many biomolecules such as proteins are electrostatically rather inhomogeneous, containing apolar, polar, and charged moieties or side chains, a water model should be able to represent the polarisation response to a local electrostatic field, while being compatible with the force field used to model the biomolecules or protein. The two polarisable water models, COS/G2 and COS/D, that are compatible with the GROMOS biomolecular force fields leave room for improvement. The COS/G2 model has a slightly too large dielectric permittivity and the COS/D model displays a much too slow dynamics. The proposed COS/D2 model has four interaction sites: only one Lennard-Jones interaction site, the oxygen atom, and three permanent charge sites, the two hydrogens, and one massless off-atom site that also serves as charge-on-spring (COS) polarisable site with a damped or sub-linear dependence of the induced dipole on the electric field strength for large values of the latter. These properties make it a cheap and yet realistic water model for biomolecular solvation.

Bachmann, Stephan J.; Gunsteren, Wilfred F. van, E-mail: wfvgn@igc.phys.chem.ethz.ch [Laboratory of Physical Chemistry, ETH Zürich, CH-8093 Zürich (Switzerland)

2014-12-14T23:59:59.000Z

323

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

SciTech Connect (OSTI)

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

324

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

SciTech Connect (OSTI)

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

325

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

SciTech Connect (OSTI)

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

326

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

SciTech Connect (OSTI)

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 1.24×1019 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

327

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

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

328

Atmospheric dispersion in mountain valleys and basins  

SciTech Connect (OSTI)

The primary goal of the research is to further characterize and understand dispersion in valley and basin atmospheres. A secondary, and related goal, is to identify and understand the dominant physical processes governing this dispersion. This has been accomplished through a review of the current literature, and analyses of recently collected data from two field experiments. This work should contribute to an improved understanding of material transport in the atmospheric boundary layer. It was found that dispersion in a freely draining valley (Brush Creek valley, CO) atmosphere is much greater than in an enclosed basin (Roanoke, VA) atmosphere primarily because of the greater wind speeds moving past the release point and the greater turbulence levels. The development of a cold air pool in the Roanoke basin is the dominant process governing nighttime dispersion in the basin, while the nighttime dispersion in the Brush Creek valley is dominated by turbulent diffusion and plume confinement between the valley sidewalls. The interaction between valley flows and above ridgetops flows is investigated. A ventilation rate'' of material transport between the valley and above ridgetop flows is determined. This is important in regional air pollution modeling and global climate modeling. A simple model of dispersion in valleys, applicable through a diurnal cycle, is proposed.

Allwine, K.J.

1992-01-01T23:59:59.000Z

329

Atmospheric dispersion in mountain valleys and basins  

SciTech Connect (OSTI)

The primary goal of the research is to further characterize and understand dispersion in valley and basin atmospheres. A secondary, and related goal, is to identify and understand the dominant physical processes governing this dispersion. This has been accomplished through a review of the current literature, and analyses of recently collected data from two field experiments. This work should contribute to an improved understanding of material transport in the atmospheric boundary layer. It was found that dispersion in a freely draining valley (Brush Creek valley, CO) atmosphere is much greater than in an enclosed basin (Roanoke, VA) atmosphere primarily because of the greater wind speeds moving past the release point and the greater turbulence levels. The development of a cold air pool in the Roanoke basin is the dominant process governing nighttime dispersion in the basin, while the nighttime dispersion in the Brush Creek valley is dominated by turbulent diffusion and plume confinement between the valley sidewalls. The interaction between valley flows and above ridgetops flows is investigated. A ``ventilation rate`` of material transport between the valley and above ridgetop flows is determined. This is important in regional air pollution modeling and global climate modeling. A simple model of dispersion in valleys, applicable through a diurnal cycle, is proposed.

Allwine, K.J.

1992-01-01T23:59:59.000Z

330

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

SciTech Connect (OSTI)

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

331

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.

332

Investigations of cloud altering effects of atmospheric aerosols using a new mixed Eulerian-Lagrangian aerosol model  

E-Print Network [OSTI]

Industry, urban development, and other anthropogenic influences have substantially altered the composition and size-distribution of atmospheric aerosol particles over the last century. This, in turn, has altered cloud ...

Steele, Henry Donnan, 1974-

2004-01-01T23:59:59.000Z

333

Cross-domain Paraphrasing For Improving Language Modelling Using Out-of-domain Data  

E-Print Network [OSTI]

Cross-domain Paraphrasing For Improving Language Modelling Using Out-of-domain Data X. Liu, M. J. F. Gales & P. C. Woodland Cambridge University Engineering Dept, Trumpington St., Cambridge, CB2 1PZ U.K. Email: {xl207,mjfg... paraphrase word sequence and weighted by its posterior probability. For a particular n-gram predicting word w i follow- ing history h i , the associated statistics C(h i , w i ) are C(h i , w i ) = ? W ? P (W ? |W)C W ? (h i , w i ) (2) where C W ? (h i , w i...

Liu, X.; Gales, M. J. F.; Woodland, P. C.

2014-01-01T23:59:59.000Z

334

Effects of improved modeling on best estimate BWR severe accident analysis  

SciTech Connect (OSTI)

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

335

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

SciTech Connect (OSTI)

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

336

Using Mesoscale Weather Model Output as Boundary Conditions for Atmospheric Large-Eddy Simulations and Wind-Plant Aerodynamic Simulations (Presentation)  

SciTech Connect (OSTI)

Wind plant aerodynamics are directly affected by the microscale weather, which is directly influenced by the mesoscale weather. Microscale weather refers to processes that occur within the atmospheric boundary layer with the largest scales being a few hundred meters to a few kilometers depending on the atmospheric stability of the boundary layer. Mesoscale weather refers to large weather patterns, such as weather fronts, with the largest scales being hundreds of kilometers wide. Sometimes microscale simulations that capture mesoscale-driven variations (changes in wind speed and direction over time or across the spatial extent of a wind plant) are important in wind plant analysis. In this paper, we present our preliminary work in coupling a mesoscale weather model with a microscale atmospheric large-eddy simulation model. The coupling is one-way beginning with the weather model and ending with a computational fluid dynamics solver using the weather model in coarse large-eddy simulation mode as an intermediary. We simulate one hour of daytime moderately convective microscale development driven by the mesoscale data, which are applied as initial and boundary conditions to the microscale domain, at a site in Iowa. We analyze the time and distance necessary for the smallest resolvable microscales to develop.

Churchfield, M. J.; Michalakes, J.; Vanderwende, B.; Lee, S.; Sprague, M. A.; Lundquist, J. K.; Moriarty, P. J.

2013-10-01T23:59:59.000Z

337

Atmospheric optical calibration system  

DOE Patents [OSTI]

An atmospheric optical calibration system is provided to compare actual atmospheric optical conditions to standard atmospheric optical conditions on the basis of aerosol optical depth, relative air mass, and diffuse horizontal skylight to global horizontal photon flux ratio. An indicator can show the extent to which the actual conditions vary from standard conditions. Aerosol scattering and absorption properties, diffuse horizontal skylight to global horizontal photon flux ratio, and precipitable water vapor determined on a real-time basis for optical and pressure measurements are also used to generate a computer spectral model and for correcting actual performance response of a photovoltaic device to standard atmospheric optical condition response on a real-time basis as the device is being tested in actual outdoor conditions. 7 figs.

Hulstrom, R.L.; Cannon, T.W.

1988-10-25T23:59:59.000Z

338

Improvements to the Hybrid2 Battery Model James F. Manwell, Jon G. McGowan, Utama Abdulwahid, and Kai Wu  

E-Print Network [OSTI]

power systems is the storage battery component. This component has a major impact on the system process. The voltage model is based on the adaptation of the Battery Energy Storage Test (or "BEST") model1 Improvements to the Hybrid2 Battery Model by James F. Manwell, Jon G. McGowan, Utama Abdulwahid

Massachusetts at Amherst, University of

339

Atmospheric Radiation Measurement Program Science Plan  

SciTech Connect (OSTI)

The Atmospheric Radiation Measurement (ARM) Program has matured into one of the key programs in the U.S. Climate Change Science Program. The ARM Program has achieved considerable scientific success in a broad range of activities, including site and instrument development, atmospheric radiative transfer, aerosol science, determination of cloud properties, cloud modeling, and cloud parameterization testing and development. The focus of ARM science has naturally shifted during the last few years to an increasing emphasis on modeling and parameterization studies to take advantage of the long time series of data now available. During the next 5 years, the principal focus of the ARM science program will be to: Maintain the data record at the fixed ARM sites for at least the next five years. Improve significantly our understanding of and ability to parameterize the 3-D cloud-radiation problem at scales from the local atmospheric column to the global climate model (GCM) grid square. Continue developing techniques to retrieve the properties of all clouds, with a special focus on ice clouds and mixed-phase clouds. Develop a focused research effort on the indirect aerosol problem that spans observations, physical models, and climate model parameterizations. Implement and evaluate an operational methodology to calculate broad-band heating rates in the atmospheric columns at the ARM sites. Develop and implement methodologies to use ARM data more effectively to test atmospheric models, both at the cloud-resolving model scale and the GCM scale. Use these methodologies to diagnose cloud parameterization performance and then refine these parameterizations to improve the accuracy of climate model simulations. In addition, the ARM Program is actively developing a new ARM Mobile Facility (AMF) that will be available for short deployments (several months to a year or more) in climatically important regions. The AMF will have much of the same instrumentation as the remote facilities at ARM's Tropical Western Pacific and the North Slope of Alaska sites. Over time, this new facility will extend ARM science to a much broader range of conditions for model testing.

Ackerman, T

2004-10-31T23:59:59.000Z

340

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

SciTech Connect (OSTI)

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

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

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

SciTech Connect (OSTI)

Cells use feedback to implement a diverse range of regulatory functions. Building synthetic feedback control systems may yield insight into the roles that feedback can play in regulation since it can be introduced independently of native regulation, and alternative control architectures can 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, the fuels are often toxic to cell growth, creating a negative feedback loop that limits biofuel production. These toxic effects may be mitigated by expressing efflux pumps that export biofuel from the cell. We developed a model for cell growth and biofuel production and used it to compare several genetic control strategies for their ability to improve biofuel yields. We show that controlling efflux pump expression directly with a biofuel-responsive promoter is a straight forward way of improving biofuel production. In addition, a feed forward loop controller is shown to be versatile at dealing with uncertainty in biofuel production rates.

Dunlop, Mary; Keasling, Jay; Mukhopadhyay, Aindrila

2011-07-14T23:59:59.000Z

342

GFDL ARM Project Technical Report: Using ARM Observations to Evaluate Cloud and Convection Parameterizations & Cloud-Convection-Radiation Interactions in the GFDL Atmospheric General Circulation Model  

SciTech Connect (OSTI)

This report briefly summarizes the progress made by ARM postdoctoral fellow, Yanluan Lin, at GFDL during the period from October 2008 to present. Several ARM datasets have been used for GFDL model evaluation, understanding, and improvement. This includes a new ice fall speed parameterization with riming impact and its test in GFDL AM3, evaluation of model cloud and radiation diurnal and seasonal variation using ARM CMBE data, model ice water content evaluation using ARM cirrus data, and coordination of the TWPICE global model intercomparison. The work illustrates the potential and importance of ARM data for GCM evaluation, understanding, and ultimately, improvement of GCM cloud and radiation parameterizations. Future work includes evaluation and improvement of the new dynamicsPDF cloud scheme and aerosol activation in the GFDL model.

V. Ramaswamy; L. J. Donner; J-C. Golaz; S. A. Klein

2010-06-17T23:59:59.000Z

343

Radar range measurements in the atmosphere.  

SciTech Connect (OSTI)

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

344

Jellylike atmospheric particles resist chemical aging Findings will affect scientific models of cloud formation and light absorption  

E-Print Network [OSTI]

sulfuric acid, helping prevent acid rain, but its nitrogen component can also fertilize open bodies of pinene SOM and adipic acid, have shown that a drop in humidity can send these common aerosols, pinene and adipic acid, are common in the Earth's atmosphere; pinene is essentially a scent released

345

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.

346

Depositional sequence analysis and sedimentologic modeling for improved prediction of Pennsylvanian reservoirs (Annex 1)  

SciTech Connect (OSTI)

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

347

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

348

Development Status of the PEBBLES Code for Pebble Mechanics: Improved Physical Models and Speed-up  

SciTech Connect (OSTI)

PEBBLES is a code for simulating the motion of all the pebbles in a pebble bed reactor. Since pebble bed reactors are packed randomly and not precisely placed, the location of the fuel elements in the reactor is not deterministically known. Instead, when determining operating parameters the motion of the pebbles can be simulated and stochastic locations can be found. The PEBBLES code can output information relevant for other simulations of the pebble bed reactors such as the positions of the pebbles in the reactor, packing fraction change in an earthquake, and velocity profiles created by recirculation. The goal for this level three milestone was to speedup the PEBBLES code through implementation on massively parallel computer. Work on this goal has resulted in speeding up both the single processor version and creation of a new parallel version of PEBBLES. Both the single processor version and the parallel running capability of the PEBBLES code have improved since the fiscal year start. The hybrid MPI/OpenMP PEBBLES version was created this year to run on the increasingly common cluster hardware profile that combines nodes with multiple processors that share memory and a cluster of nodes that are networked together. The OpenMP portions use the Open Multi-Processing shared memory parallel processing model to split the task across processors in a single node that shares memory. The Message Passing Interface (MPI) portion uses messages to communicate between different nodes over a network. The following are wall clock speed up for simulating an NGNP-600 sized reactor. The single processor version runs 1.5 times faster compared to the single processor version at the beginning of the fiscal year. This speedup is primarily due to the improved static friction model described in the report. When running on 64 processors, the new MPI/OpenMP hybrid version has a wall clock speed up of 22 times compared to the current single processor version. When using 88 processors, a speed up of 23 times is achieved. This speedup and other improvements of PEBBLES combine to make PEBBLES more capable and more useful for simulation of a pebble bed reactor. This report details the implementation and effects of the speedup work done over the course of the fiscal year.

Joshua J. Cogliati; Abderrafi M. Ougouag

2009-12-01T23:59:59.000Z

349

Large-Signal HBT Model with Improved Collector Transit Time Formulation for GaAs and InP Technologies  

E-Print Network [OSTI]

mi': iaE Large-Signal HBT Model with Improved Collector Transit Time Formulation for GaAs and In large-signal HBT model which accurately accounts for the intricate hias dependence of collector delay collector delay function accounts for the variation of electron velocity with electric field

Asbeck, Peter M.

350

Improving land-surface model hydrology: Is an explicit aquifer model better than a deeper soil profile?  

E-Print Network [OSTI]

land-surface model hydrology: Is an explicit aquifer modelAL. : LAND-SURFACE MODEL HYDROLOGY Changnon, S. , et al. (land-surface model hydrology: Is an explicit aquifer model

2007-01-01T23:59:59.000Z

351

atmospheric dispersion coefficient: Topics by E-print Network  

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

the earth surface. In general, the atmospheric motion is driven by the intense solar energy arriving at the equator 3 A GIS-based atmospheric dispersion model Computer...

352

atmospheric dispersion calculations: Topics by E-print Network  

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

the earth surface. In general, the atmospheric motion is driven by the intense solar energy arriving at the equator 4 A GIS-based atmospheric dispersion model Computer...

353

atmospheric dispersion experiment: Topics by E-print Network  

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

the earth surface. In general, the atmospheric motion is driven by the intense solar energy arriving at the equator 2 A GIS-based atmospheric dispersion model Computer...

354

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

355

DOE Final Report for DE-FG02-01ER63198 Title: IMPROVING THE PROCESSES OF LAND-ATMOSPHERE INTERACTION IN CCSM 2.0 AT HIGHER RESOLUTION AND BETTER SUB-GRID SCALING  

SciTech Connect (OSTI)

Our CCPP project consists of the development and testing of a systematic sub-grid scaling framework for the CLM. It consists of four elements: i) a complex vegetation tiling representation; ii) an orographic tiling system; iii) a tiling system to describe a distribution of water table parameters intended to provide a realistic statistical model of wetlands; and iv) improvements of past developed treatments of precipitation intensity.

Dr. Robert Dickinson

2008-08-16T23:59:59.000Z

356

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 (OSTI)

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

357

Modeling of collision-induced infrared absorption spectra of H2-H2 pairs in the fundamental band at temperatures from 20 to 300 K. [Planetary atmospheres  

SciTech Connect (OSTI)

The 20-300 K free-free rotovibrational collision-induced absorption (RV CIA) spectra of H2-H2 pairs are presently obtained by a numerical method which, in addition to closely matching known CIA spectra of H2-H2, can reproduce the results of the quantum-mechanical computations to within a few percent. Since the spectral lineshape parameters are derivable by these means from the lowest three quantum-mechanical spectral moments, these outer-planet atmosphere-pertinent model spectra may be computed on even small computers. 35 refs.

Borysow, A. (Michigan Technological University, Houghton (United States))

1991-08-01T23:59:59.000Z

358

Aerosol Effects on Cirrus through Ice Nucleation in the Community Atmosphere Model CAM5 with a Statistical Cirrus Scheme  

SciTech Connect (OSTI)

A statistical cirrus cloud scheme that tracks ice saturation ratio in the clear-sky and cloudy portion of a grid box separately has been implemented into NCAR CAM5 to provide a consistent treatment of ice nucleation and cloud formation. Simulated ice supersaturation and ice crystal number concentrations strongly depend on the number concentrations of heterogeneous ice nuclei (IN), subgrid temperature formulas and the number concentration of sulfate particles participating in homogeneous freezing, while simulated ice water content is insensitive to these perturbations. 1% to 10% dust particles serving as heterogeneous IN is 20 found to produce ice supersaturaiton in better agreement with observations. Introducing a subgrid temperature perturbation based on long-term aircraft observations of meso-scale motion produces a better hemispheric contrast in ice supersaturation compared to observations. Heterogeneous IN from dust particles significantly alter the net radiative fluxes at the top of atmosphere (TOA) (-0.24 to -1.59 W m-2) with a significant clear-sky longwave component (0.01 to -0.55 W m-2). Different cirrus treatments significantly perturb the net TOA anthropogenic aerosol forcing from -1.21 W m-2 to -1.54 W m-2, with a standard deviation of 0.10 W m-2. Aerosol effects on cirrus clouds exert an even larger impact on the atmospheric component of the radiative fluxes (two or three times the changes in the TOA radiative fluxes) and therefore on the hydrology cycle through the fast atmosphere response. This points to the urgent need to quantify aerosol effects on cirrus clouds through ice nucleation and how these further affect the hydrological cycle.

Wang, Minghuai; Liu, Xiaohong; Zhang, Kai; Comstock, Jennifer M.

2014-09-01T23:59:59.000Z

359

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 (OSTI)

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

360

Ecosystem feedbacks to climate change in California: Development, testing, and analysis using a coupled regional atmosphere and land-surface model (WRF3-CLM3.5)  

SciTech Connect (OSTI)

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

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 Aerosol Systems | EMSL  

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

Science Themes Atmospheric Aerosol Systems Overview Atmospheric Aerosol Systems Biosystem Dynamics & Design Energy Materials & Processes Terrestrial & Subsurface Ecosystems...

362

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

363

Improvements to the RELAP5/MOD3 reflood model and uncertainty quantification of reflood peak clad temperature  

SciTech Connect (OSTI)

Assessment of the original REAP/N4OD3.1 code against the FLECHT SEASET series of experiments has identified some weaknesses of the reflood model, such as the lack of a quenching temperature model, the shortcoming of the Chen transition boiling model, and the incorrect prediction of droplet size and interfacial heat transfer. Also, high temperature spikes during the reflood calculation resulted in high steam flow oscillation and liquid carryover. An effort had been made to improve the code with respect to the above weakness, and the necessary model for the wall heat transfer package and the numerical scheme had been modified. Some important FLECHT-SEASET experiments were assessed using the improved version and standard version. The result from the improved REAP/MOD3.1 shows the weaknesses of REAP/N4OD3.1 were much improved when compared to the standard MOD3.1 code. The prediction of void profile and cladding temperature agreed better with test data, especially for the gravity feed test. The scatter diagram of peak cladding temperatures (PCTs) is made from the comparison of all the calculated PCTs and the corresponding experimental values. The deviation between experimental and calculated PCTs were calculated for 2793 data points. The deviations are shown to be normally distributed, and used to quantify statistically the PCT uncertainty of the code. The upper limit of PCT uncertainty at 95% confidence level is evaluated to be about 99K.

Chung, Bub Dong; Lee, Young Lee; Park, Chan Eok; Lee, Sang Yong [Korea Atomic Energy Research Institute, Yusung, Taejon (Korea, Republic of)] [and others

1996-10-01T23:59:59.000Z

364

Improving Testing of Enterprise Systems by Model-based Testing on Graphical User Sebastian Wieczorek and Alin Stefanescu  

E-Print Network [OSTI]

complexity, an efficient testing approach should be automatic. Since the underlying business processesImproving Testing of Enterprise Systems by Model-based Testing on Graphical User Interfaces--Software development and testing of Enterprise Resource Planning (ERP) systems demands dedicated methods to tackle its

Southampton, University of

365

Where do fossil fuel carbon dioxide emissions from California go? An analysis based on radiocarbon observations and an atmospheric transport model  

SciTech Connect (OSTI)

Characterizing flow patterns and mixing of fossil fuel-derived CO{sub 2} is important for effectively using atmospheric measurements to constrain emissions inventories. Here we used measurements and a model of atmospheric radiocarbon ({sup 14}C) to investigate the distribution and fluxes of atmospheric fossil fuel CO{sub 2} across the state of California. We sampled {sup 14}C in annual C{sub 3} grasses at 128 sites and used these measurements to test a regional model that simulated anthropogenic and ecosystem CO{sub 2} fluxes, transport in the atmosphere, and the resulting {sup 14}C of annual grasses ({Delta}{sub g}). Average measured {Delta}{sub g} in Los Angeles, San Francisco, the Central Valley, and the North Coast were 27.7 {+-} 20.0, 44.0 {+-} 10.9, 48.7 {+-} 1.9, and 59.9 {+-} 2.5{per_thousand}, respectively, during the 2004-2005 growing season. Model predictions reproduced regional patterns reasonably well, with estimates of 27.6 {+-} 2.4, 39.4 {+-} 3.9, 46.8 {+-} 3.0, and 59.3 {+-} 0.2{per_thousand} for these same regions and corresponding to fossil fuel CO{sub 2} mixing ratios (Cf) of 13.7, 6.1, 4.8, and 0.3 ppm. {Delta}{sub g} spatial heterogeneity in Los Angeles and San Francisco was higher in the measurements than in the predictions, probably from insufficient spatial resolution in the fossil fuel inventories (e.g., freeways are not explicitly included) and transport (e.g., within valleys). We used the model to predict monthly and annual transport patterns of fossil fuel-derived CO{sub 2} within and out of California. Fossil fuel CO{sub 2} emitted in Los Angeles and San Francisco was predicted to move into the Central Valley, raising Cf above that expected from local emissions alone. Annually, about 21, 39, 35, and 5% of fossil fuel emissions leave the California airspace to the north, east, south, and west, respectively, with large seasonal variations in the proportions. Positive correlations between westward fluxes and Santa Ana wind conditions were observed. The southward fluxes over the Pacific Ocean were maintained in a relatively coherent flow within the marine boundary layer, while the eastward fluxes were more vertically dispersed. Our results indicate that state and continental scale atmospheric inversions need to consider areas where concentration measurements are sparse (e.g., over the ocean to the south and west of California), transport within and across the marine boundary layer, and terrestrial boundary layer dynamics. Measurements of {Delta}{sub g} can be very useful in constraining these estimates.

Riley, W.J.; Hsueh, D.Y.; Randerson, J.T.; Fischer, M.L.; Hatch, J.G.; Pataki, D.E.; Wang, W.; Goulden, M.L.

2008-05-01T23:59:59.000Z

366

TRANSMISSION SPECTRA OF TRANSITING PLANET ATMOSPHERES: MODEL VALIDATION AND SIMULATIONS OF THE HOT NEPTUNE GJ 436b FOR THE JAMES WEBB SPACE TELESCOPE  

SciTech Connect (OSTI)

We explore the transmission spectrum of the Neptune-class exoplanet GJ 436b, including the possibility that its atmospheric opacity is dominated by a variety of nonequilibrium chemical products. We also validate our transmission code by demonstrating close agreement with analytic models that use only Rayleigh scattering or water vapor opacity. We find broad disagreement with radius variations predicted by another published model. For GJ 436b, the relative coolness of the planet's atmosphere, along with its implied high metallicity, may make it dissimilar in character compared to 'hot Jupiters'. Some recent observational and modeling efforts suggest low relative abundances of H{sub 2}O and CH{sub 4} present in GJ 436b's atmosphere, compared to calculations from equilibrium chemistry. We include these characteristics in our models and examine the effects of absorption from methane-derived higher-order hydrocarbons. To our knowledge, the effects of these nonequilibrium chemical products on the spectra of close-in giant planets have not previously been investigated. Significant absorption from HCN and C{sub 2}H{sub 2} is found throughout the infrared, while C{sub 2}H{sub 4} and C{sub 2}H{sub 6} are less easily seen. We perform detailed simulations of James Webb Space Telescope observations, including all likely noise sources, and find that we will be able to constrain chemical abundance regimes from this planet's transmission spectrum. For instance, the width of the features at 1.5, 3.3, and 7 {mu}m indicates the amount of HCN versus C{sub 2}H{sub 2} present. The NIRSpec prism mode will be useful due to its large spectral range and the relatively large number of photo-electrons recorded per spectral resolution element. However, extremely bright host stars like GJ 436 may be better observed with a higher spectroscopic resolution mode in order to avoid detector saturation. We find that observations with the MIRI low-resolution spectrograph should also have high signal-to-noise in the 5-10 {mu}m range due to the brightness of the star and the relatively low spectral resolution (R {approx} 100) of this mode.

Shabram, Megan [Department of Astronomy, University of Florida, 211 Bryant Space Center, Gainesville, FL 32611 (United States); Fortney, Jonathan J. [Department of Astronomy and Astrophysics, University of California, Santa Cruz, CA 95064 (United States); Greene, Thomas P.; Freedman, Richard S. [Space Science and Astrobiology Division, NASA Ames Research Center, Mail Stop 245-3, Moffett Field, CA 94035 (United States)

2011-02-01T23:59:59.000Z

367

Impact of horizontal resolution on simulation of precipitation extremes in an aqua-planet version of the Community Atmosphere Model (CAM)  

SciTech Connect (OSTI)

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

368

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

369

Toward Improved Identifiability of Soil Hydraulic Parameters: On the Selection of a Suitable Parametric Model  

E-Print Network [OSTI]

paramet- kind of observational data (Zachmann et al., 1981; Koolric model structure and provides useful

Vrugt, Jasper A.

370

Using A-Train Arctic cloud observations to constrain and improve climate models  

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

AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE:1 First Use of Energy for All Purposes (Fuel and Nonfuel),Feet) Year Jan Feb Mar Apr MayAtmosphericNuclear SecurityTensile Strain Switched Ferromagnetism inS-4500II Field Emission SEMUsedUser ServicesUsers June radiation

371

SciTech Connect: Using a Simple Binomial Model to Assess Improvement in  

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

AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE:1 First Use of Energy for All Purposes (Fuel and Nonfuel),Feet) Year Jan Feb Mar Apr MayAtmosphericNuclear Security Administrationcontroller systemsBi (2) Sr (2) CawithMicrofluidicJournal Article: Unitarity

372

Wind Forecast Model Validation & Improvement for the Central U.S. | The  

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

AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE:1 First Use of Energy for All Purposes (Fuel and Nonfuel),Feet) Year Jan Feb Mar Apr MayAtmosphericNuclear SecurityTensile Strain Switched FerromagnetismWaste and MaterialsWenjun DengWISP SignInWhoWillistonWEFOctoberAmes

373

Improved zircon fission-track annealing model based on reevaluation of  

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

AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE:1 First Use of Energy for All Purposes (Fuel and Nonfuel),Feet) Year Jan Feb Mar Apr MayAtmospheric Optical Depth7-1D: Vegetation ProposedUsingFun withconfinementEtching.348 270 300 219 255Retrievals

374

SPRAYTRAN 1.0 User’s Guide: A GIS-Based Atmospheric Spray Droplet Dispersion Modeling System  

SciTech Connect (OSTI)

SPRAY TRANsport (SPRAYTRAN) is a comprehensive dispersion modeling system that is used to simulate the offsite drift of pesticides from spray applications. SPRAYTRAN functions as a console application within Environmental System Research Institute’s ArcMap Geographic Information System (Version 9.x) and integrates the widely-used, U.S. Environmental Protection Agency (EPA)-approved CALifornia PUFF (CALPUFF) dispersion model and model components to simulate longer-range transport and diffusion in variable terrain and spatially/temporally varying meteorological (e.g., wind) fields. Area sources, which are used to define spray blocks in SPRAYTRAN, are initialized using output files generated from a separate aerial-spray-application model called AGDISP (AGricultural DISPersal). The AGDISP model is used for estimating the amount of pesticide deposited to the spray block based on spraying characteristics (e.g., pesticide type, spray nozzles, and aircraft type) and then simulating the near-field (less than 300-m) drift from a single pesticide application. The fraction of pesticide remaining airborne from the AGDISP near-field simulation is then used by SPRAYTRAN for simulating longer-range (greater than 300 m) drift and deposition of the pesticide.

Allwine, K Jerry; Rutz, Frederick C.; Droppo, James G.; Rishel, Jeremy P.; Chapman, Elaine G.; Bird, S. L.; Thistle, Harold W.

2006-09-20T23:59:59.000Z

375

Improving the Fanger model's thermal comfort predictions for naturally ventilated spaces  

E-Print Network [OSTI]

The Fanger model is the official thermal comfort model in U.S. and international standards and is based on the heat balance of the human body with the environment. This investigation focuses on re-specifying the parameters ...

Truong, Phan Hue

2010-01-01T23:59:59.000Z

376

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

E-Print Network [OSTI]

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

Im, Eun-Soon

377

Geosynchronous orbit determination using space surveillance network observations and improved radiative force modeling  

E-Print Network [OSTI]

Correct modeling of the space environment, including radiative forces, is an important aspect of space situational awareness for geostationary (GEO) spacecraft. Solar radiation pressure has traditionally been modeled using ...

Lyon, Richard Harry, 1981-

2004-01-01T23:59:59.000Z

378

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

379

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

E-Print Network [OSTI]

with statistical analysis Anthony Ung, Laure Malherbe, Frederik Meleux, Bertrand Bessagnet, Laurence Rouil and MACCII modeling team INERIS institut, Paris, France Corresponding author: Anthony.ung@ineris.fr Abstract/QC dossiers and available on the MACC project website for each model. All models have also very significant

Paris-Sud XI, Université de

380

Systematic Improvement of a Classical Molecular Model of Water Lee-Ping Wang,  

E-Print Network [OSTI]

-consistent polarizable model such as AMOEBA. The model is parameterized using ForceBalance, a systematic optimization calculations. We show that iAMOEBA is a highly accurate model for water in the solid, liquid, and gas phases properties beyond the training data set including the phase diagram. The increased accuracy of iAMOEBA over

Ponder, Jay

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

E-Print Network 3.0 - atmospheric diffusion experiments Sample...  

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

382

E-Print Network 3.0 - atmospheric fine elemental Sample Search...  

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

383

E-Print Network 3.0 - atmospheric experiment recherche Sample...  

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

384

E-Print Network 3.0 - atmospheric interference Sample Search...  

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

385

E-Print Network 3.0 - atmospheric stability conditions Sample...  

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

wind park model considering atmospheric stability. Wind... : A simple analytical wind park model considering atmospheric stability. Wind Energy, 13, 459-469. 12... : A...

386

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

387

New formulae to evaluate the atmospheric layers of precipitable water and gases, applicable in solar radiation computing models  

E-Print Network [OSTI]

in solar radiation computing models V. B0103descu Energetica, Centrale Electrice, Polytechn. Inst irradiance. In this context, the relatively low density of solar radiation recording stations favoured measurements. Reviews and classifications of the main calculations procedures of solar radiation have been

Paris-Sud XI, Université de

388

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

389

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

390

Integrating Empirical-Modeling Approaches to Improve Understanding of Terrestrial Ecology Processes  

SciTech Connect (OSTI)

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

391

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

E-Print Network [OSTI]

environmental partitioning of DDT in two global multimediaInvestigating the global fate of DDT: model evaluation andinsecticides dicofol and DDT in an aerosol smog chamber

Schenker, Urs

2010-01-01T23:59:59.000Z

392

Integrated reservoir characterization: Improvement in heterogeneities stochastic modelling by integration of additional external constraints  

SciTech Connect (OSTI)

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

393

Computational Model of Forward and Opposed Smoldering Combustion with Improved Chemical Kinetics (PhD. Thesis)  

E-Print Network [OSTI]

fixed beds of oil shale grains: governing parameters and global regimes, Combustionfixed beds of oil shale grains. A three-dimensional microscale numerical model, Combustion

Rein, Guillermo

2005-01-01T23:59:59.000Z

394

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

395

Development of Improved Models and Designs for Coated-Particle Gas Reactor Fuels (I-NERI Annual Report)  

SciTech Connect (OSTI)

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

396

AtmoHEAD 2013 workshop / Atmospheric Monitoring for High-Energy Astroparticle Detectors  

E-Print Network [OSTI]

A 3-day international workshop on atmospheric monitoring and calibration for high-energy astroparticle detectors, with a view towards next-generation facilities. The atmosphere is an integral component of many high-energy astroparticle detectors. Imaging atmospheric Cherenkov telescopes and cosmic-ray extensive air shower detectors are the two instruments driving the rapidly evolving fields of very-high- and ultra-high-energy astrophysics. In these instruments, the atmosphere is used as a giant calorimeter where cosmic rays and gamma rays deposit their energy and initiate EASs; it is also the medium through which the resulting Cherenkov light propagates. Uncertainties in real-time atmospheric conditions and in the fixed atmospheric models typically dominate all other systematic errors. With the improved sensitivity of upgraded IACTs such as H.E.S.S.-II and MAGIC-II and future facilities like the Cherenkov Telescope Array (CTA) and JEM-EUSO, statistical uncertainties are expected to be significantly reduced, leaving the atmosphere as the limiting factor in the determination of astroparticle spectra. Varying weather conditions necessitate the development of suitable atmospheric monitoring to be integrated in the overall instrument calibration, including Monte Carlo simulations. With expertise distributed across multiple collaborations and scientific domains, an interdisciplinary workshop is being convened to advance progress on this critical and timely topic.

K. Bernlöhr; G. Bellassai; O. Blanch; M. Bourgeat; P. Bruno; M. Buscemi; C. Cassardo; P. M. Chadwick; R. Chalme-Calvet; F. Chouza; M. Cilmo; M. Coco; J. Colombi; M. Compin; M. K. Daniel; R. De Los Reyes; J. Ebr; R. D'Elia; C. Deil; A. Etchegoyen; M. Doro; S. Ferrarese; M. Fiorini; LL. Font; D. Garrido; H. Gast; M. Gaug; F. Gonzales; A. Grillo; F. Guarino; J. Hahn; M. Hrabovsky; K. Kosack; P. Krüger; G. La Rosa; G. Leto; Y. T. E. Lo; A. López-Oramas; K. Louedec; M. C. Maccarone; D. Mandat; V. Marandon; E. Martinetti; M. Martinez; M. de Naurois; A. Neronov; S. J. Nolan; L. Otero; M. Palatka; J. Pallotta; M. Pech; G. Puhlhofer; M. Prouza; E. Quel; D. Raul; P. Ristori; M. D. Rodriguez Frias; S. Rivoire; C. B. Rulten; P. Schovanek; A. Segreto; G. Sottile; L. Stringhetti; J. -P. Tavernet; A. S. Tonachini; S. Toscano; P. Travnicek; L. Valore; G. Vasileiadis; S. Vincent; S. Wada; L. Wiencke; M. Will

2014-03-19T23:59:59.000Z

397

A Comprehensive Parameterization of Heterogeneous Ice Nucleation of Dust Surrogate: Laboratory Study with Hematite Particles and Its Application to Atmospheric Models  

SciTech Connect (OSTI)

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

398

The Asperity-deformation Model Improvements and Its Applications to Velocity Inversion  

E-Print Network [OSTI]

. . . . . . . . . . . . . . . . . . . . . 2 1.2.1 Fracture modeling . . . . . . . . . . . . . . . . . . 3 1.2.2 Thelinkbetweenfracturecharacterizationand seismic data . . . . . . . . . . . . . . . . . . . . . 4 1.2.3 Seismic modeling of CO2 sequestration in frac- tured reservoirs... . . . . . . . . . . . . . . . . . . . 6 1.2.4 The influence of pressure . . . . . . . . . . . . . . 7 1.3 Research objectives . . . . . . . . . . . . . . . . . . . . 8 1.4 Dissertation outline . . . . . . . . . . . . . . . . . . . . 9 1.4.1 Chapter II - Theoretical study of the asperity...

Bui, Hoa Q.

2010-01-16T23:59:59.000Z

399

On testing the significance of atmospheric response to smoke from the Kuwaiti oil fires using the Los Alamos general circulation model  

SciTech Connect (OSTI)

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

400

Atmospheric science and power production  

SciTech Connect (OSTI)

This is the third in a series of scientific publications sponsored by the US Atomic Energy Commission and the two later organizations, the US Energy Research and Development Adminstration, and the US Department of Energy. The first book, Meteorology and Atomic Energy, was published in 1955; the second, in 1968. The present volume is designed to update and to expand upon many of the important concepts presented previously. However, the present edition draws heavily on recent contributions made by atmospheric science to the analysis of air quality and on results originating from research conducted and completed in the 1970s. Special emphasis is placed on how atmospheric science can contribute to solving problems relating to the fate of combustion products released into the atmosphere. The framework of this book is built around the concept of air-quality modeling. Fundamentals are addressed first to equip the reader with basic background information and to focus on available meteorological instrumentation and to emphasize the importance of data management procedures. Atmospheric physics and field experiments are described in detail to provide an overview of atmospheric boundary layer processes, of how air flows around obstacles, and of the mechanism of plume rise. Atmospheric chemistry and removal processes are also detailed to provide fundamental knowledge on how gases and particulate matter can be transformed while in the atmosphere and how they can be removed from the atmosphere. The book closes with a review of how air-quality models are being applied to solve a wide variety of problems. Separate analytics have been prepared for each chapter.

Randerson, D. (ed.)

1984-07-01T23:59:59.000Z

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.


401

Annual Report: Property Improvement in CZT via Modeling and Processing Innovations  

SciTech Connect (OSTI)

The objective of this project is to develop growth models of CZT crystals from the melt using vertical gradient freeze (VGF) or vertical Bridgman growth as a typical process. Further, the project will perform critical experiments including single crystal growth to validate the growth models and to provide detailed data for modeling and simulation. Ideally, the project will develop growth models that will provide, for the first time, choices for optimal CZT single crystal growth from the melt based on model input. The overarching goal that guides this research proposal is to produce large, single crystals of CZT with good yield and reproducible properties. In our view this depends on 1) understanding crystal growth processes, including annealing and cool-down processing, and 2) understanding the role of defects on detector response since it is not possible, yet, to produce defect-free materials. Models of defect structure and formation are addressed. Validated models and experiments on reducing defects in melt-grown crystals are used to guide our understanding of growth processes and in-furnace annealing plus cool-down.

Henager, Charles H.; Setyawan, Wahyu; Gao, Fei; Hu, Shenyang Y.; Bliss, Mary; Riley, Brian J.; Alvine, Kyle J.; Stave, Jean A.

2013-09-01T23:59:59.000Z

402

Improved Multivariate Calibration Models for Corn Stover Feedstock and Dilute-Acid Pretreated Corn Stover  

SciTech Connect (OSTI)

We have studied rapid calibration models to predict the composition of a variety of biomass feedstocks by correlating near-infrared (NIR) spectroscopic data to compositional data produced using traditional wet chemical analysis techniques. The rapid calibration models are developed using multivariate statistical analysis of the spectroscopic and wet chemical data. This work discusses the latest versions of the NIR calibration models for corn stover feedstock and dilute-acid pretreated corn stover. Measures of the calibration precision and uncertainty are presented. No statistically significant differences (p = 0.05) are seen between NIR calibration models built using different mathematical pretreatments. Finally, two common algorithms for building NIR calibration models are compared; no statistically significant differences (p = 0.05) are seen for the major constituents glucan, xylan, and lignin, but the algorithms did produce different predictions for total extractives. A single calibration model combining the corn stover feedstock and dilute-acid pretreated corn stover samples gave less satisfactory predictions than the separate models.

Wolfrum, E. J.; Sluiter, A. D.

2009-01-01T23:59:59.000Z

403

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

404

The Energy Spectrum of Atmospheric Neutrinos between 2 and 200 TeV with the AMANDA-II Detector  

SciTech Connect (OSTI)

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

405

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

406

Collection Policy: SOIL, CROP AND ATMOSPHERIC SCIENCES Subject Scope | Priority Tables | Other policies . . .  

E-Print Network [OSTI]

. q Microclimatology. q Air pollution. q Atmospheric modeling. q The Engineering Library hasCollection Policy: SOIL, CROP AND ATMOSPHERIC SCIENCES Subject Scope | Priority Tables | Other; atmospheric phenomena, prediction, modeling; geographical information systems; soil survey; microbial

Angenent, Lars T.

407

Improving Rainfall Processes in Climate Models | U.S. DOE Office...  

Office of Science (SC) Website

Bldg. 815E, Upton, NY 11973-5000 hsong@bnl.gov Funding This work is supported by the Earth System Modeling program within the Department of Energy's Office of Biological and...

408

Improving capabilities for dealing with key complexities of water availability modeling  

E-Print Network [OSTI]

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

Olmos Alejo, Hector Elias

2005-02-17T23:59:59.000Z

409

Improving efficiency of a vehicle HVAC system with comfort modeling, zonal  

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

AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page on Google Bookmark EERE: Alternative Fuels Data Center Home Page on Delicious Rank EERE:YearRound-UpHeatMulti-Dimensionalthe U.S. Improving Fan System Performance a PumpingReduceddesign,

410

ISO-SWS calibration and the accurate modelling of cool-star atmospheres - III. A0 to G2 stars  

E-Print Network [OSTI]

Vega, Sirius, Beta Leo, Alpha Car and Alpha Cen A belong to a sample of twenty stellar sources used for the calibration of the detectors of the Short-Wavelength Spectrometer on board the Infrared Space Observatory (ISO-SWS). While general problems with the calibration and with the theoretical modelling of these stars are reported in Decin et al. (2002), each of these stars is discussed individually in this paper. As demonstrated in Decin et al. (2002), it is not possible to deduce the effective temperature, the gravity and the chemical composition from the ISO-SWS spectra of these stars. But since ISO-SWS is absolutely calibrated, the angular diameter of these stellar sources can be deduced from their ISO-SWS spectra, which consequently yields the stellar radius (R), the gravity-inferred mass (M) and the luminosity (L) for these stars. These deduced parameters are confronted with other published values and the goodness-of-fit between observed ISO-SWS data and the corresponding synthetic spectrum is discussed.

L. Decin; B. Vandenbussche; C. Waelkens; K. Eriksson; B. Gustafsson; B. Plez; A. J. Sauval

2002-07-29T23:59:59.000Z

411

Environmental assessment for the Atmospheric Radiation Measurement (ARM) Program: Southern Great Plains Cloud and Radiation Testbed (CART) site  

SciTech Connect (OSTI)

The Atmospheric Radiation Measurement (ARM) Program is aimed at supplying improved predictive capability of climate change, particularly the prediction of cloud-climate feedback. The objective will be achieved by measuring the atmospheric radiation and physical and meteorological quantities that control solar radiation in the earth`s atmosphere and using this information to test global climate and related models. The proposed action is to construct and operate a Cloud and Radiation Testbed (CART) research site in the southern Great Plains as part of the Department of Energy`s Atmospheric Radiation Measurement Program whose objective is to develop an improved predictive capability of global climate change. The purpose of this CART research site in southern Kansas and northern Oklahoma would be to collect meteorological and other scientific information to better characterize the processes controlling radiation transfer on a global scale. Impacts which could result from this facility are described.

Policastro, A.J.; Pfingston, J.M.; Maloney, D.M.; Wasmer, F.; Pentecost, E.D.

1992-03-01T23:59:59.000Z

412

ISO-SWS calibration and the accurate modelling of cool-star atmospheres - IV. G9 to M2 stars  

E-Print Network [OSTI]

presented. The 2.38 -- 4.08 micron wavelength-range of band 1 of ISO-SWS (Short-Wavelength Spectrometers on board of the Infrared Space Observatory) in which many different molecules -- with their own dependence on each of the stellar parameters -- are absorbing, enables us to estimate the effective temperature, the gravity, the microturbulence, the metallicity, the CNO-abundances, the 12C/13C-ratio and the angular diameter from the ISO-SWS data. Using the Hipparcos' parallax, the radius, luminosity and gravity-inferred mass are derived. The stellar parameters obtained are in good agreement with other published values, though also some discrepancies with values deduced by other authors are noted. For a few stars (Delta Dra, Xi Dra, Alpha Tuc, H Sco and Alpha Cet) some parameters -- e.g. the CNO-abundances -- are derived for the first time. By examining the correspondence between different ISO-SWS observations of the same object and between the ISO-SWS data and the corresponding synthetic spectrum, it is shown that the relative accuracy of ISO-SWS in band 1 (2.38 -- 4.0 micron) is better than 2% for these high-flux sources. The high level of correspondence between observations and theoretical predictions, together with a confrontation of the estimated Teff(ISO) value with Teff-values derived from colours -- which demonstrates the consistency between V-K, BC(K), Teff and the angular diameter derived from optical or IR data -- proves that both the used MARCS models to derive the stellar quantities and the flux calibration of the ISO-SWS detectors have reached a high level of reliability.

L. Decin; B. Vandenbussche; C. Waelkens; G. Decin; K. Eriksson; B. Gustafsson; B. Plez; A. J. Sauval

2002-07-30T23:59:59.000Z

413

Modeling Improvements for Air Source Heat Pumps using Different Expansion Devices at Varied Charge Levels Part II  

SciTech Connect (OSTI)

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

414

Reexamination of the State of the Art Cloud Modeling Shows Real Improvements  

SciTech Connect (OSTI)

Following up on an almost thirty year long history of International Cloud Modeling Workshops, that started out with a meeting in Irsee, Germany in 1985, the 8th International Cloud Modeling Workshop was held in July 2012 in Warsaw, Poland. The workshop, hosted by the Institute of Geophysics at the University of Warsaw, was organized by Szymon Malinowski and his local team of students and co-chaired by Wojciech Grabowski (NCAR/MMM) and Andreas Muhlbauer (University of Washington). International Cloud Modeling Workshops have been held traditionally every four years typically during the week before the International Conference on Clouds and Precipitation (ICCP) . Rooted in the World Meteorological Organization’s (WMO) weather modification program, the core objectives of the Cloud Modeling Workshop have been centered at the numerical modeling of clouds, cloud microphysics, and the interactions between cloud microphysics and cloud dynamics. In particular, the goal of the workshop is to provide insight into the pertinent problems of today’s state-of-the-art of cloud modeling and to identify key deficiencies in the microphysical representation of clouds in numerical models and cloud parameterizations. In recent years, the workshop has increasingly shifted the focus toward modeling the interactions between aerosols and clouds and provided case studies to investigate both the effects of aerosols on clouds and precipitation as well as the impact of cloud and precipitation processes on aerosols. This time, about 60 (?) scientists from about 10 (?) different countries participated in the workshop and contributed with discussions, oral and poster presentations to the workshop’s plenary and breakout sessions. Several case leaders contributed to the workshop by setting up five observationally-based case studies covering a wide range of cloud types, namely, marine stratocumulus, mid-latitude squall lines, mid-latitude cirrus clouds, Arctic stratus and winter-time orographic clouds and precipitation. Interested readers are encouraged to visit the workshop website at http://www.atmos.washington.edu/~andreasm/workshop2012/ and browse through the list of case studies. The web page also provides a detailed list of participants and the workshop agenda. Aside from contributed oral and poster presentations during the workshop’s plenary sessions, parallel breakout sessions focused on presentations and discussions of the individual cases. A short summary and science highlights from each of the cases is presented below.

Muehlbauer, Andreas D.; Grabowski, Wojciech W.; Malinowski, S. P.; Ackerman, Thomas P.; Bryan, George; Lebo, Zachary; Milbrandt, Jason; Morrison, H.; Ovchinnikov, Mikhail; Tessendorf, Sarah; Theriault, Julie M.; Thompson, Gregory

2013-05-25T23:59:59.000Z

415

Improving alternative fuel utilization: detailed kinetic combustion...  

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

Improving alternative fuel utilization: detailed kinetic combustion modeling & experimental testing Improving alternative fuel utilization: detailed kinetic combustion modeling &...

416

Test of Lorentz invariance with atmospheric neutrinos  

E-Print Network [OSTI]

A search for neutrino oscillations induced by Lorentz violation has been performed using 4,438 live-days of Super-Kamiokande atmospheric neutrino data. The Lorentz violation is included in addition to standard three-flavor oscillations using the non-perturbative Standard Model Extension (SME), allowing the use of the full range of neutrino path lengths, ranging from 15 to 12,800 km, and energies ranging from 100 MeV to more than 100 TeV in the search. No evidence of Lorentz violation was observed, so limits are set on the renormalizable isotropic SME coefficients in the $e\\mu$, $\\mu\\tau$, and $e\\tau$ sectors, improving the existing limits by up to seven orders of magnitude and setting limits for the first time in the neutrino $\\mu\\tau$ sector of the SME.

The Super-Kamiokande Collaboration; :; K. Abe; Y. Haga; Y. Hayato; M. Ikeda; K. Iyogi; J. Kameda; Y. Kishimoto; M. Miura; S. Moriyama; M. Nakahata; Y. Nakano; S. Nakayama; H. Sekiya; M. Shiozawa; Y. Suzuki; A. Takeda; H. Tanaka; T. Tomura; K. Ueno; R. A. Wendell; T. Yokozawa; T. Irvine; T. Kajita; I. Kametani; K. Kaneyuki; K. P. Lee; T. McLachlan; Y. Nishimura; E. Richard; K. Okumura; L. Labarga; P. Fernandez; J. Gustafson; E. Kearns; J. L. Raaf; S. Berkman; H. A. Tanaka; S. Tobayama; J. L. Stone; L. R. Sulak; M. Goldhaber; G. Carminati; W. R. Kropp; S. Mine; P. Weatherly; A. Renshaw; M. B. Smy; H. W. Sobel; V. Takhistov; K. S. Ganezer; B. L. Hartfiel; J. Hill; W. E. Keig; N. Hong; J. Y. Kim; I. T. Lim; T. Akiri; A. Himmel; K. Scholberg; C. W. Walter; T. Wongjirad; T. Ishizuka; S. Tasaka; J. S. Jang; J. G. Learned; S. Matsuno; S. N. Smith; T. Hasegawa; T. Ishida; T. Ishii; T. Kobayashi; T. Nakadaira; K. Nakamura; Y. Oyama; K. Sakashita; T. Sekiguchi; T. Tsukamoto; A. T. Suzuki; Y. Takeuchi; C. Bronner; S. Hirota; K. Huang; K. Ieki; T. Kikawa; A. Minamino; A. Murakami; T. Nakaya; K. Suzuki; S. Takahashi; K. Tateishi; Y. Fukuda; K. Choi; Y. Itow; G. Mitsuka; P. Mijakowski; J. Hignight; J. Imber; C. K. Jung; C. Yanagisawa; H. Ishino; A. Kibayashi; Y. Koshio; T. Mori; M. Sakuda; R. Yamaguchi; T. Yano; Y. Kuno; R. Tacik; S. B. Kim; H. Okazawa; Y. Choi; K. Nishijima; M. Koshiba; Y. Suda; Y. Totsuka; M. Yokoyama; K. Martens; Ll. Marti; M. R. Vagins; J. F. Martin; P. de Perio; A. Konaka; M. J. Wilking; S. Chen; Y. Zhang; K. Connolly; R. J. Wilkes

2015-03-17T23:59:59.000Z

417

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

E-Print Network [OSTI]

An energy analysis was performed on the Texas A & M University at Qatar building in Doha, Qatar. The building and its HVAC systems were modeled using EnergyPlus. Building chilled water and electrical data were collected to validate the computer...

Bible, Mitchell

2011-10-21T23:59:59.000Z

418

PaperCeptInc How can model driven development approaches improve the  

E-Print Network [OSTI]

verification, validation and certification of the final product at an early stage of the development life cycle model driven development approaches that are inherited from existing aerospace and aeronautical systems that are inherited from existing aerospace and aeronautical system developments and that could be useful

Paris-Sud XI, Université de

419

An improved cosmological model fitting of Planck data with a dark energy spike  

E-Print Network [OSTI]

The $\\Lambda$ cold dark matter ($\\Lambda\\textrm{CDM}$) model is currently known as the simplest cosmology model that best describes observations with minimal number of parameters. Here we introduce a cosmology model that is preferred over the conventional $\\Lambda\\textrm{CDM}$ one by constructing dark energy as the sum of the cosmological constant $\\Lambda$ and the additional fluid that is designed to have an extremely short transient spike in energy density during the radiation-matter equality era and the early scaling behavior with radiation and matter densities. The density parameter of the additional fluid is defined as a Gaussian function plus a constant in logarithmic scale-factor space. Searching for the best-fit cosmological parameters in the presence of such a dark energy spike gives a far smaller chi-square value by about five times the number of additional parameters introduced and narrower constraints on matter density and Hubble constant compared with the best-fit $\\Lambda\\textrm{CDM}$ model. The...

Park, Chan-Gyung

2015-01-01T23:59:59.000Z

420

IEEE TRANSACTIONS ON AUDIO, SPEECH AND LANGUAGE PROCESSING 1 Model-Based Speech Enhancement with Improved  

E-Print Network [OSTI]

IEEE TRANSACTIONS ON AUDIO, SPEECH AND LANGUAGE PROCESSING 1 Model-Based Speech Enhancement-based approach to enhance noisy speech using an analysis-synthesis framework. Target speech is reconstructed. Ini- tially, we propose an analysis-synthesis framework for speech enhancement based on harmonic noise

So, Hing-Cheung

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

Improved Modeling and Understanding of Diffusion-Media Wettability on Polymer-Electrolyte-Fuel-Cell Performance  

SciTech Connect (OSTI)

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

422

On an improved sub-regional water resources management representation for integration into earth system models  

SciTech Connect (OSTI)

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

423

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

E-Print Network [OSTI]

(IE), semantic role labeling (SRL), or question an- swering (QA). Learning a model for a particular is that it is very simple to implement; it also allows for a modular approach to natural language process- ing is to solve the tasks separately and integrate the constraints in a linear programming formulation

Bunescu, Razvan C.

424

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

425

Depositional sequence analysis and sedimentologic modeling for improved prediction of Pennsylvanian reservoirs  

SciTech Connect (OSTI)

Reservoirs in the Lansing-Kansas City limestone result from complex interactions among paleotopography (deposition, concurrent structural deformation), sea level, and diagenesis. Analysis of reservoirs and surface and near-surface analogs has led to developing a {open_quotes}strandline grainstone model{close_quotes} in which relative sea-level stabilized during regressions, resulting in accumulation of multiple grainstone buildups along depositional strike. Resulting stratigraphy in these carbonate units are generally predictable correlating to inferred topographic elevation along the shelf. This model is a valuable predictive tool for (1) locating favorable reservoirs for exploration, and (2) anticipating internal properties of the reservoir for field development. Reservoirs in the Lansing-Kansas City limestones are developed in both oolitic and bioclastic grainstones, however, re-analysis of oomoldic reservoirs provides the greatest opportunity for developing bypassed oil. A new technique, the {open_quotes}Super{close_quotes} Pickett crossplot (formation resistivity vs. porosity) and its use in an integrated petrophysical characterization, has been developed to evaluate extractable oil remaining in these reservoirs. The manual method in combination with 3-D visualization and modeling can help to target production limiting heterogeneities in these complex reservoirs and moreover compute critical parameters for the field such as bulk volume water. Application of this technique indicates that from 6-9 million barrels of Lansing-Kansas City oil remain behind pipe in the Victory-Northeast Lemon Fields. Petroleum geologists are challenged to quantify inferred processes to aid in developing rationale geologically consistent models of sedimentation so that acceptable levels of prediction can be obtained.

Watney, W.L.

1994-12-01T23:59:59.000Z

426

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

427

Improved zircon fission-track annealing model based on reevaluation of annealing data  

SciTech Connect (OSTI)

The thermal recovery (annealing) of mineral structure modified by the passage of fission fragments has long been studied by the etching technique. In minerals like apatite and zircon, the annealing kinetics are fairly well constrained from the hour to the million-year timescale and have been described by empirical and semi-empirical equations. On the other hand, laboratory experiments, in which ion beams interact with minerals and synthetic ceramics, have shown that there is a threshold temperature beyond which thermal recovery impedes ion-induced amorphization. In this work, it is assumed that this behavior can be extended to the annealing of fission tracks in minerals. It is proposed that there is a threshold temperature, T0, beyond which fission tracks are erased within a time t0, which is independent of the current state of lattice deformation. This implies that iso-annealing curves should converge to a fanning point in the Arrhenius pseudo-space (ln t vs. 1/T). Based on the proposed hypothesis, and laboratory and geological data, annealing equations are reevaluated. The geological timescale estimations of a model arising from this study are discussed through the calculation of partial annealing zone and closure temperature, and comparison with geological sample constraints found in literature. It is shown that the predictions given by this model are closer to field data on closure temperature and partial annealing zone than predictions given by previous models.

Guedes, Sandro [Instituto de Fisica Gleb Wataghin, Unicamp, Brazil; Moreira, Pedro A.F.P. [Universidade Estadual de Campinas, Sao Paulo; Devanathan, Ram [Pacific Northwest National Laboratory (PNNL); Weber, William J [ORNL; Hadler, Julio C [Instituto de Fisica Gleb Wataghin, Unicamp, Brazil

2013-01-01T23:59:59.000Z

428

Improved zircon fission-track annealing model based on reevaluation of annealing data  

SciTech Connect (OSTI)

The thermal recovery (annealing) of mineral structure modified by the passage of fission fragments has long been studied by the etching technique. In minerals like apatite and zircon, the annealing kinetics are fairly well constrained from the hour to the million-year timescale and have been described by empirical and semi-empirical equations. On the other hand, laboratory experiments, in which ion beams interact with minerals and synthetic ceramics, have shown that there is a threshold temperature beyond which thermal recovery impedes ion-induced amorphization. In this work, it is assumed that this behavior can be extended to the annealing of fission tracks in minerals. It is proposed that there is a threshold temperature, T 0, beyond which fission tracks are erased within a time t 0, which is independent of the current state of lattice deformation. This implies that iso-annealing curves should converge to a fanning point in the Arrhenius pseudo-space (ln t vs. 1/T). Based on the proposed hypothesis, and laboratory and geological data, annealing equations are reevaluated. The geological timescale estimations of a model arising from this study are discussed through the calculation of partial annealing zone and closure temperature, and comparison with geological sample constraints found in literature. It is shown that the predictions given by this model are closer to field data on closure temperature and partial annealing zone than predictions given by previous models.

Guedes, S.; Moreira, Pedro; Devanathan, Ramaswami; Weber, William J.; Hadler, J. C.

2013-02-01T23:59:59.000Z

429

HEATING THE ATMOSPHERE ABOVE SUNSPOTS  

E-Print Network [OSTI]

become fragmented and twisted, and where they generate the necessary energy to heat the solar coronaHEATING THE ATMOSPHERE ABOVE SUNSPOTS David Alexander and Neal E. Hurlburt Lockheed Martin Solar, University of Cambridge, Cambridge, CB3 9EW, UK Abstract We present our results of a hybrid model of sunspots

Rucklidge, Alastair

430

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]

74 ii Soil Moisture Sensors: Decagon ECH2O Capacitance133 A.10 Soil types corresponding to each75 Soil Moisture and Temperature Probe

Daniels, Megan Hanako

2010-01-01T23:59:59.000Z

431

Constraining the influence of natural variability to improve estimates of global aerosol indirect effects in a nudged version of the Community Atmosphere Model 5  

E-Print Network [OSTI]

Zhao (2006), A simulated climatology of Asian dust aerosolN) PI (F) ? PI (F) ? X ? 2000 (PD Climatology) ? ? 2000 (PD Climatology) ? PD (F) X a All simulations used the same

Kooperman, Gabriel J; Pritchard, Michael S; Ghan, Steven J; Wang, Minghuai; Somerville, Richard C. J; Russell, Lynn M

2012-01-01T23:59:59.000Z

432

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]

red indicates “water towers” generated by kinematic wavethe kinematic wave equation will begin to collect water onred indicates “water towers” generated by kinematic wave

Daniels, Megan Hanako

2010-01-01T23:59:59.000Z

433

Constraining the influence of natural variability to improve estimates of global aerosol indirect effects in a nudged version of the Community Atmosphere Model 5  

E-Print Network [OSTI]

the northern hemisphere Pacific Ocean and along the westernacross the northern Pacific Ocean, coincident with regionsthe Northern Hemisphere Pacific Ocean and off the northwest

Kooperman, Gabriel J; Pritchard, Michael S; Ghan, Steven J; Wang, Minghuai; Somerville, Richard C. J; Russell, Lynn M

2012-01-01T23:59:59.000Z

434

Constraining the influence of natural variability to improve estimates of global aerosol indirect effects in a nudged version of the Community Atmosphere Model 5  

E-Print Network [OSTI]

by direct emission inventories; sea salt and dust enter the32 ] Direct emission inventories represent the only sourcesemissions from prescribed inventories and parameterized

Kooperman, Gabriel J; Pritchard, Michael S; Ghan, Steven J; Wang, Minghuai; Somerville, Richard C. J; Russell, Lynn M

2012-01-01T23:59:59.000Z

435

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]

direction, (b) wind speed, (c) potential temperature, and (Airport of potential temperature, wind speed, winderrors (bias) for potential temperature, wind speed, wind

Daniels, Megan Hanako

2010-01-01T23:59:59.000Z

436

Model Developments for Development of Improved Emissions Scenarios: Developing Purchasing-Power Parity Models, Analyzing Uncertainty, and Developing Data Sets for Gridded Integrated Assessment Models  

SciTech Connect (OSTI)

In the duration of this project, we finished the main tasks set up in the initial proposal. These tasks include: setting up the basic platform in GAMS language for the new RICE 2007 model; testing various model structure of RICE 2007; incorporating PPP data set in the new RICE model; developing gridded data set for IA modeling.

Yang, Zili; Nordhaus, William

2009-03-19T23:59:59.000Z

437

Validation of detailed thermal hydraulic models used for LMR safety and for improvement of technical specifications  

SciTech Connect (OSTI)

Detailed steady-state and transient coolant temperatures and flow rates from an operating reactor have been used to validate the multiple pin model in the SASSYS-1 liquid metal reactor systems analysis code. This multiple pin capability can be used for explicit calculations of axial and lateral temperature distributions within individual subassemblies. Thermocouples at a number of axial locations and in a number of different coolant sub-channels m the XXO9 instrumented subassembly in the EBR-II reactor provided temperature data from the Shutdown Heat Removal Test (SHRT) series. Flow meter data for XXO9 and for the overall system are also available from these tests. Results of consistent SASSYS-1 multiple pin analyses for both the SHRT-45 loss-of-flow-without-scram-test and the S14RT-17 protected loss-of-flow test agree well with the experimental data, providing validation of the SASSYS-1 code over a wide range of conditions.

Dunn, F.E.

1995-12-31T23:59:59.000Z

438

Modeling and Diagnostics of Fuel Cell Porous Media for Improving Water Transport  

SciTech Connect (OSTI)

When a fuel cell is operating at high current density, water accumulation is a significant cause of performance and component degradation. Investigating the water transport inside the fuel cell is a challenging task due to opacity of the components, the randomness of the porous materials, and the difficulty in gain access to the interior for measurement due to the small dimensions of components. Numerical simulation can provide a good insight of the evolution of the water transport under different working condition. However, the validation of those simulations is remains an issue due the same experimental obstacles associated with in-situ measurements. The discussion herein will focus on pore-network modeling of the water transport on the PTL and the insights gained from simulations as well as in the validation technique. The implications of a recently published criterion to characterize PTL, based on percolation theory, and validate numerical simulation are discussed.

Allen, Jeff; M'edici, Ezequiel

2011-07-01T23:59:59.000Z

439

Three-body Interactions Improve the Prediction of Rate and Mechanism in Protein Folding Models  

E-Print Network [OSTI]

Here we study the effects of many-body interactions on rate and mechanism in protein folding, using the results of molecular dynamics simulations on numerous coarse-grained C-alpha-model single-domain proteins. After adding three-body interactions explicitly as a perturbation to a Go-like Hamiltonian with native pair-wise interactions only, we have found 1) a significantly increased correlation with experimental phi-values and folding rates, 2) a stronger correlation of folding rate with contact order, matching the experimental range in rates when the fraction of three-body energy in the native state is ~ 20%, and 3) a considerably larger amount of 3-body energy present in Chymotripsin inhibitor than other proteins studied.

M. R. Ejtehadi; S. P. Avall; S. S. Plotkin

2004-07-14T23:59:59.000Z

440

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

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

Doctoral Programs Atmospheric, Oceanic & Space Sciences  

E-Print Network [OSTI]

University of Michigan Space Research Building 2455 Hayward Street Ann Arbor, MI 48109-2143 aoss Katherine E. White, Ann Arbor ©The Regents of the University of Michigan Research areas Atmospheric Science Atmospheric Dynamics Climate, Climate Modeling & Climate Change Clouds & Precipitation Paleoclimate, Ice

Eustice, Ryan

442

Atmospheric Radiation Measurement Climate Research Facility (ACRF) Annual Report 2008  

SciTech Connect (OSTI)

The Importance of Clouds and Radiation for Climate Change: The Earth’s surface temperature is determined by the balance between incoming solar radiation and thermal (or infrared) radiation emitted by the Earth back to space. Changes in atmospheric composition, including greenhouse gases, clouds, and aerosols, can alter this balance and produce significant climate change. Global climate models (GCMs) are the primary tool for quantifying future climate change; however, there remain significant uncertainties in the GCM treatment of clouds, aerosol, and their effects on the Earth’s energy balance. In 1989, the U.S. Department of Energy (DOE) Office of Science created the Atmospheric Radiation Measurement (ARM) Program to address scientific uncertainties related to global climate change, with a specific focus on the crucial role of clouds and their influence on the transfer of radiation in the atmosphere. To reduce these scientific uncertainties, the ARM Program uses a unique twopronged approach: • The ARM Climate Research Facility, a scientific user facility for obtaining long-term measurements of radiative fluxes, cloud and aerosol properties, and related atmospheric characteristics in diverse climate regimes; and • The ARM Science Program, focused on the analysis of ACRF and other data to address climate science issues associated with clouds, aerosols, and radiation, and to improve GCMs. This report provides an overview of each of these components and a sample of achievements for each in fiscal year (FY) 2008.

LR Roeder

2008-12-01T23:59:59.000Z

443

Climate Sciences: Atmospheric Thermodynamics  

E-Print Network [OSTI]

1 Climate Sciences: Atmospheric Thermodynamics Instructor: Lynn Russell, NH343 http://aerosol.ucsd.edu/courses.html Text: Curry & Webster Atmospheric Thermodynamics Ch1 Composition Ch2 Laws Ch3 Transfers Ch12 Energy Climate Sciences: Atmospheric Thermodynamics Instructor: Lynn Russell, NH343 http

Russell, Lynn

444

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

445

Final report for the project "Improving the understanding of surface-atmosphere radiative interactions by mapping surface reflectance over the ARM CART site" (award DE-FG02-02ER63351)  

SciTech Connect (OSTI)

Surface spectral reflectance (albedo) is a fundamental variable affecting the transfer of solar radiation and the Earth’s climate. It determines the proportion of solar energy absorbed by the surface and reflected back to the atmosphere. The International Panel on Climate Change (IPCC) identified surface albedo among key factors influencing climate radiative forcing. Accurate knowledge of surface reflective properties is important for advancing weather forecasting and climate change impact studies. It is also important for determining radiative impact and acceptable levels of greenhouse gases in the atmosphere, which makes this work strongly linked to major scientific objectives of the Climate Change Research Division (CCRD) and Atmospheric Radiation Measurement (ARM) Program. Most significant accomplishments of eth project are listed below. I) Surface albedo/BRDF datasets from 1995 to the end of 2004 have been produced. They were made available to the ARM community and other interested users through the CCRS public ftp site ftp://ftp.ccrs.nrcan.gc.ca/ad/CCRS_ARM/ and ARM IOP data archive under “PI data Trishchenko”. II) Surface albedo properties over the ARM SGP area have been described for 10-year period. Comparison with ECMWF data product showed some deficiencies in the ECMWF surface scheme, such as missing some seasonal variability and no dependence on sky-conditions which biases surface energy budget and has some influence of the diurnal cycle of upward radiation and atmospheric absorption. III) Four surface albedo Intensive Observation Period (IOP) Field Campaigns have been conducted for every season (August, 2002, May 2003, February 2004 and October 2004). Data have been prepared, documented and transferred to ARM IOP archive. Nine peer-reviewed journal papers and 26 conference papers have been published.

Alexander P. Trishchenko; Yi Luo; Konstantin V. Khlopenkov, William M. Park; Zhanqing Li; Maureen Cribb

2008-11-28T23:59:59.000Z

446

Development and Testing of a Life Cycle Model and a Parameterization of Thin Mid-level Stratiform Clouds  

SciTech Connect (OSTI)

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

447

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

448

Improving Thermal Model Prediction Through Statistical Analysis of Irradiation and Post-Irradiation Data from AGR Experiments  

SciTech Connect (OSTI)

As part of the Research and Development program for Next Generation High Temperature Reactors (HTR), a series of irradiation tests, designated as Advanced Gas-cooled Reactor (AGR), have been defined to support development and qualification of fuel design, fabrication process, and fuel performance under normal operation and accident conditions. The AGR tests employ fuel compacts placed in a graphite cylinder shrouded by a steel capsule and instrumented with thermocouples (TC) embedded in graphite blocks enabling temperature control. The data representing the crucial test fuel conditions (e.g., temperature, neutron fast fluence, and burnup) while impossible to obtain from direct measurements are calculated by physics and thermal models. The irradiation and post-irradiation examination (PIE) experimental data are used in model calibration effort to reduce the inherent uncertainty of simulation results. This paper is focused on fuel temperature predicted by the ABAQUS code’s finite element-based thermal models. The work follows up on a previous study, in which several statistical analysis methods were adapted, implemented in the NGNP Data Management and Analysis System (NDMAS), and applied for improving qualification of AGR-1 thermocouple data. The present work exercises the idea that the abnormal trends of measured data observed from statistical analysis may be caused by either measuring instrument deterioration or physical mechanisms in capsules that may have shifted the system thermal response. As an example, the uneven reduction of the control gas gap in Capsule 5 revealed by the capsule metrology measurements in PIE helps justify the reduction in TC readings instead of TC drift. This in turn prompts modification of thermal model to better fit with experimental data, thus help increase confidence, and in other word reduce model uncertainties in thermal simulation results of the AGR-1 test.

Dr. Binh T. Pham; Grant L. Hawkes; Jeffrey J. Einerson

2012-10-01T23:59:59.000Z

449

Modal Bin Hybrid Model: A Surface Area Consistent, Triple Moment Sectional Method for Use in Process-oriented Modeling of Atmospheric Aerosols  

SciTech Connect (OSTI)

A triple moment sectional method, Modal Bin Hybrid Model (MBHM), has been developed. In addition to number and mass (volume), surface area is predicted (and preserved), which is important for gas-to-particle mass transfer and light extinction cross section. The performance of MBHM was evaluated against double moment sectional (DMS) methods with various size resolutions up to BIN256 (BINx: x is number of sections over three orders of magnitude in size, ?logD = 3/x) for simulating evolution of particles under simultaneously occurring nucleation, condensation and coagulation processes. Because MBHM gives a physically consistent form of the intra-sectional distributions, errors and biases of MBHM at BIN4-8 resolution were almost equivalent to those of DMS at BIN16-32 resolution for various important variables such as the moments Mk (k: 0, 2, 3), dMk/dt, and the number and volume of particles larger than a certain diameter. Another important feature of MBHM is that only a single bin is adequate to simulate full aerosol dynamics for particles whose size distribution can be approximated by a single lognormal mode. This flexibility is useful for process-oriented (multi category and/or mixing state) modeling: primary aerosols whose size parameters would not differ substantially in time and space can be expressed by a single or a small number of modes, whereas secondary aerosols whose size changes drastically from one to several hundred nanometers can be expressed by a number of modes. Added dimensions can be applied to MBHM to represent mixing state or photo-chemical age for aerosol mixing state studies.

Kajino, Mizuo; Easter, Richard C.; Ghan, Steven J.

2013-09-10T23:59:59.000Z

450

Cell motility in models of wounded human skin is improved by Gap27 despite raised glucose, insulin and IGFBP-5  

SciTech Connect (OSTI)

Reducing Cx43 expression stimulates skin wound healing. This is mimicked in models when Cx43 function is blocked by the connexin mimetic peptide Gap27. IGF-I also stimulates wound healing with IGFBP-5 attenuating its actions. Further, the IGF-I to IGFBP-5 ratio is altered in diabetic skin, where wound closure is impaired. We investigated whether Gap27 remains effective in augmenting scrape-wound closure in human skin wound models simulating diabetes-induced changes, using culture conditions with raised glucose, insulin and IGFBP-5. Gap27 increased scrape-wound closure in normal glucose and insulin (NGI) and to a lesser extent in high glucose and insulin (HGI). IGF-I enhanced scrape-wound closure in keratinocytes whereas IGFBP-5 inhibited this response. Gap27 overcame the inhibitory effects of IGFBP-5 on IGF-I activity. Connexin-mediated communication (CMC) was reduced in HGI, despite raised Cx43, and Gap27 significantly decreased CMC in NGI and HGI. IGF-I and IGFBP-5 did not affect CMC. IGF-I increased keratinocyte proliferation in NGI, and Gap27 increased proliferation in NGI to a greater extent than in HGI. We conclude that IGF-I and Gap27 stimulate scrape-wound closure by independent mechanisms with Gap27 inhibiting Cx43 function. Gap27 can enhance wound closure in diabetic conditions, irrespective of the IGF-I:IGFBP-5 balance. - Highlights: ? Human organotypic and keratinocyte ‘diabetic’ skin models were used to demonstrate the ability of Gap27 to improve scrape-wound closure. ? Gap27 enhanced scrape-wound closure by reducing Cx43-mediated communication, whereas IGFBP-5 retarded cell migration. ? IGF-I and IGFBP-5 did not affect connexin-mediated pathways. ? Gap27 can override altered glucose, insulin, IGF-I, and IGFBP-5 in ‘diabetic’ skin models and thus has therapeutic potential.

Wright, Catherine S.; Berends, Rebecca F. [Department of Life Sciences, School of Health and Life Sciences, Glasgow Caledonian University, 70 Cowcaddens Road, Glasgow G4 0BA (United Kingdom); Flint, David J. [Strathclyde Institute of Pharmacy and Biomedical Sciences, University of Strathclyde, 161 Cathedral Street, Glasgow G4 0RE (United Kingdom); Martin, Patricia E.M., E-mail: Patricia.Martin@gcu.ac.uk [Department of Life Sciences, School of Health and Life Sciences, Glasgow Caledonian University, 70 Cowcaddens Road, Glasgow G4 0BA (United Kingdom)

2013-02-15T23:59:59.000Z

451

AtmosphericAtmospheric Composition Introduction The division investigates the atmospheric  

E-Print Network [OSTI]

development on observation side was the installation of an ozone observation station in Surinam in close co-operation with the Surinam Meteorological Service. Processes in the tropical regions are important for the global climate and the global atmospheric composition. The participation in Indoex (Indian Ocean Experiment) and this Surinam

Haak, Hein

452

Development of Improved Models and Designs for Coated-Particle Gas Reactor Fuels -- Final Report under the International Nuclear Energy Research Initiative (I-NERI)  

SciTech Connect (OSTI)

The objective of this INERI project was to develop improved fuel behavior models for gas reactor coated-particle fuels and to explore improved coated-particle fuel designs that could be used reliably at very high burnups and potentially in gas-cooled fast reactors. Project participants included the Idaho National Engineering Laboratory (INEEL), Centre Étude Atomique (CEA), and the Massachusetts Institute of Technology (MIT). To accomplish the project objectives, work was organized into five tasks.

David Petti; Philippe Martin; Mayeul Phélip; Ronald Ballinger; Petti does not have NT account

2004-12-01T23:59:59.000Z

453

Atmospheric Neutrino Fluxes  

E-Print Network [OSTI]

Starting with an historical review, I summarize the status of calculations of the flux of atmospheric neutrinos and how they compare to measurements.

Thomas K. Gaisser

2005-02-18T23:59:59.000Z

454

Origin of the Springtime Westerly Bias in Equatorial Atlantic Surface Winds in the Community Atmosphere Model Version 3 (CAM3) Simulation  

E-Print Network [OSTI]

­atmosphere interaction generally rules. 1. Introduction Trade winds (easterlies) prevail over most of the tropical in the cen- tral and eastern basins, and vice versa. Along the equa- tor, easterly winds generate equatorialOrigin of the Springtime Westerly Bias in Equatorial Atlantic Surface Winds in the Community

Nigam, Sumant

455

Atmospheric Carbon Dioxide Variability in the Community Earth System Model: Evaluation and Transient Dynamics during the Twentieth and Twenty-First Centuries  

E-Print Network [OSTI]

predictions from CMIP5 Earth system models and comparisonin the Community Earth System Model: Evaluation andusing the Community Earth System Model–Biogeochemistry (

2013-01-01T23:59:59.000Z

456

An improved neutral diffusion model and numerical solution of the two dimensional edge plasma fluid equations. Final report  

SciTech Connect (OSTI)

In this work, it has been shown that, for the given sets of parameters (transport coefficients), the Tangent-Predictor (TP) continuation method, which was used in the coarsest grid, works remarkably well. The problems in finding an initial guess that resides well within Newton`s method radius of convergence are alleviated by correcting the initial guess by the predictor step of the TP method. The TP method works well also in neutral gas puffing and impurity simulations. The neutral gas puffing simulation is performed by systematically increasing the fraction of puffing rate according to the TP method until it reaches a desired condition. Similarly, the impurity simulation characterized by using the fraction of impurity density as the continuation parameter, is carried out in line with the TP method. Both methods show, as expected, a better performance than the classical embedding (CE) method. The convergence criteria {epsilon} is set to be 10{sup {minus}9} based on the fact that lower value of {epsilon} does not alter the solution significantly. Correspondingly, the number of Newton`s iterations in the corrector step of the TP method decrease substantially, an extra point in terms of code speed. The success of the TP method enlarges the possibility of including other sets of parameters (operations and physics). With the availability of the converged coarsest grid solution, the next forward step to the multigrid cycle becomes possible. The multigrid method shows that the memory storage problems that plagued the application of Newton`s method on fine grids, are of no concern. An important result that needs to be noted here is the performance of the FFCD model. The FFCD model is relatively simple and is based on the overall results the model has shown to predict different divertor plasma parameters. The FFCD model treats exactly the implementation of the deep penetration of energetic neutrals emerging from the divertor plate. The resulting ionization profiles are relatively smooth as a consequence of the less localized recycling, leading to an improved convergence rate of the numerical algorithm. Peak plasma density is lower and the temperature correspondingly higher than those predicted by the standard diffusion model. It is believed that the FFCD model is more accurate. With both the TP continuation and multigrid methods, the author has demonstrated the robustness of these two methods. A mutually beneficial hybridization between the TP method and multigrid methods is clearly an alternative for edge plasma simulation. While the fundamental transport model considered in this work has ignored important physics such as drifts and currents, he has nevertheless demonstrated the versatility and robustness of the numerical scheme to handle such new physics. The application of gaseous-radiative divertor model in this work is just a beginning and up to this point numerically, the future is exciting.

Prinja, A.K.

1998-09-01T23:59:59.000Z

457

MERCURY IN THE ATMOSPHERE, BIOSPHERE, AND POLICY SPHERE  

E-Print Network [OSTI]

MERCURY IN THE ATMOSPHERE, BIOSPHERE, AND POLICY SPHERE: Insights from global modeling Noelle Atmospheric Chemistry Program #12;FROM ATMOSPHERE TO FISH: MERCURY RISING Ice core from Wyoming [Schuster et al., ES&T 2002] Mercury deposition has increased by 300% since industrialization Major anthropogenic

Selin, Noelle Eckley

458

A correlated K-distribution model of the heating rates for H[sub 2]O and a molecular mixture in the 0-2500 cm[sup [minus]1] wavelength region in the atmosphere between 0 and 60 km  

SciTech Connect (OSTI)

For this report a prototype infrared radiative transfer model using a correlated k-distribution technique to calculate the transmission between atmospheric levels has been used to calculate the radiative fluxes and heating rates for H[sub 2]O and a mixture of the major molecular absorbers in the atmosphere between 0 and 60 km. The mixture consists of H[sub 2]O, CO[sub 2], O[sub 3], CH[sub 4], and N[sub 2]O. The wave number range considered is 0-2500 cm[sup [minus]1]. The use of the k-distribution method allows 25 cm[sup [minus]1] wave number bins to produce fluxes and heating rates which are within ten percent of the results of detailed line by line calculations.

Grossman, A S; Grant, K E

1992-11-16T23:59:59.000Z

459

Atmospheric Thermodynamics Composition  

E-Print Network [OSTI]

1 Atmospheric Thermodynamics Ch1 Composition Ch2 Laws Ch3 Transfers Ch12 EnergyBalance Ch4 Water Ch Sciences: Atmospheric Thermodynamics Instructor: Lynn Russell, NH343 http #12;2 Review from Ch. 1 · Thermodynamic quantities · Composition · Pressure · Density · Temperature

Russell, Lynn

460

Atmospheric Dynamics II Instructor  

E-Print Network [OSTI]

AT602 Atmospheric Dynamics II 2 credits Instructor: David W. J. Thompson davet: An Introduction to Dynamic Meteorology, 5th Edition, Academic Press (recommended) · Marshall, J., and Plumb, R. A., 2008: Atmosphere, Ocean, and Climate Dynamics: An Introductory Text, Academic Press. · Vallis, G. K

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.