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1

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

Science Journals Connector (OSTI)

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

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

2014-11-01T23:59:59.000Z

2

Solar Radiation Estimated Through Mesoscale Atmospheric Modeling over Northeast Brazil  

Science Journals Connector (OSTI)

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

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

2009-01-01T23:59:59.000Z

3

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

E-Print Network (OSTI)

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

Kurapov, Alexander

4

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

Science Journals Connector (OSTI)

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

Tommaso Benacchio; Warren P. O’Neill; Rupert Klein

2014-12-01T23:59:59.000Z

5

Mesoscale Atmospheric Dispersion, 2001, Ed. Z. Boybeyi, WIT Publications, Southampton, UK, Advances in Air Pollution, Vol 9, p. 424.  

E-Print Network (OSTI)

surface­atmosphere exchanges in mesoscale air pollution systems Devdutta S. Niyogi & Sethu Raman NorthMesoscale Atmospheric Dispersion, 2001, Ed. Z. Boybeyi, WIT Publications, Southampton, UK, Advances in Air Pollution, Vol 9, p. 424. Chapter 9 Numerical modeling of gas deposition and bi- directional

Raman, Sethu

6

Mesoscale Waves as a Probe of Jupiter's Deep Atmosphere  

Science Journals Connector (OSTI)

Search of the Voyager images of Jupiter reveals a class of mesoscale waves occurring near the extrema of the zonal velocity profile between latitudes 30°S and 30°N. The average horizontal wavelength is 300 km, compared to an atmospheric scale ...

F. M. Flasar; P. J. Gierasch

1986-11-01T23:59:59.000Z

7

Mesoscale Coupled Ocean-Atmosphere Interaction  

E-Print Network (OSTI)

heat flux, and wind power input to the ocean. Geophys. Res.Powers and Stoelinga (2000). They developed a comprehensive atmosphere-ocean-

Seo, Hyodae

2007-01-01T23:59:59.000Z

8

Mesoscale coupled ocean-atmosphere interaction  

E-Print Network (OSTI)

heat flux, and wind power input to the ocean. Geophys. Res.Powers and Stoelinga (2000). They developed a comprehensive atmosphere-ocean-

Seo, Hyodae

2007-01-01T23:59:59.000Z

9

A Climatological Study of Boundary Layer Wind Speed Using a Meso-?-Scale Higher-Order Closure Model  

Science Journals Connector (OSTI)

A mesoscale higher-order closure atmospheric boundary layer model has been used to get more detailed information than is possible from observations regarding horizontal and vertical variations of the wind in an area in southeastern Sweden. To ...

Hans Bergström

1996-08-01T23:59:59.000Z

10

Rotational and divergent kinetic energy in the mesoscale model ALADIN  

E-Print Network (OSTI)

Rotational and divergent kinetic energy in the mesoscale model ALADIN By V. BLAZ ICA1 *, N. Z AGAR1 received 7 June 2012; in final form 7 March 2013) ABSTRACT Kinetic energy spectra from the mesoscale. It is shown that about 50% of kinetic energy in the free troposphere in ALADIN is divergent energy

Zagar, Nedjeljka

11

Coupling a Mesoscale Numerical Weather Prediction Model with Large-Eddy Simulation for Realistic Wind Plant Aerodynamics Simulations (Poster)  

SciTech Connect

Wind plant aerodynamics are influenced by a combination of microscale and mesoscale phenomena. Incorporating mesoscale atmospheric forcing (e.g., diurnal cycles and frontal passages) into wind plant simulations can lead to a more accurate representation of microscale flows, aerodynamics, and wind turbine/plant performance. Our goal is to couple a numerical weather prediction model that can represent mesoscale flow [specifically the Weather Research and Forecasting model] with a microscale LES model (OpenFOAM) that can predict microscale turbulence and wake losses.

Draxl, C.; Churchfield, M.; Mirocha, J.; Lee, S.; Lundquist, J.; Michalakes, J.; Moriarty, P.; Purkayastha, A.; Sprague, M.; Vanderwende, B.

2014-06-01T23:59:59.000Z

12

ADVANCES IN ATMOSPHERIC SCIENCES, VOL. 27, NO. 2, 2010, 243252 Mesoscale Barotropic Instability of Vortex Rossby  

E-Print Network (OSTI)

ADVANCES IN ATMOSPHERIC SCIENCES, VOL. 27, NO. 2, 2010, 243­252 Mesoscale Barotropic Instability of Vortex Rossby Waves in Tropical Cyclones ZHONG Wei1 ( Í), LU Han-Cheng1 (ö ), and Da-Lin ZHANG2 1 Institute of Meteorology, PLA University of Science and Technology, Nanjing 211101 2 Department

Zhang, Da-Lin

13

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

E-Print Network (OSTI)

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

Daniels, Megan Hanako

2010-01-01T23:59:59.000Z

14

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

Science Journals Connector (OSTI)

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

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

2011-03-01T23:59:59.000Z

15

MESOSCALE MODELLING OF WIND ENERGY OVER NON-HOMOGENEOUS TERRAIN  

E-Print Network (OSTI)

MESOSCALE MODELLING OF WIND ENERGY OVER NON-HOMOGENEOUS TERRAIN (ReviewArticle) Y. MAHRER.1. OBSERVATIONALAPPROACHES Evaluations of wind energy based on wind observations (usually surface winds) at well, the resolution of the wind energy pattern throughout an extended area by this methodology requires a large number

Pielke, Roger A.

16

WIND ATLAS FOR EGYPT: MEASUREMENTS, MICRO-AND MESOSCALE MODELLING  

E-Print Network (OSTI)

WIND ATLAS FOR EGYPT: MEASUREMENTS, MICRO- AND MESOSCALE MODELLING Niels G. Mortensen1 , Jens Energy Authority, Cairo, Egypt Ahmed El Sayed Yousef, Adel Mahmoud Awad, Mahmoud Abd-El Raheem Ahmed Meteorological Authority, Cairo, Egypt ABSTRACT The results of a comprehensive, 8-year wind resource assessment

17

The Advection of Mesoscale Atmospheric Vortices over Reykjavík  

Science Journals Connector (OSTI)

On 12 August 2009, a series of satellite images revealed asymmetric shedding of atmospheric vortices in the lee of Mt. Snæfellsjökull, and their passage a distance of 120 km across Faxaflói Bay and over the city of Reykjavík in West Iceland. After ...

Hálfdán Ágústsson; Haraldur Ólafsson

2014-10-01T23:59:59.000Z

18

Mesoscale Modeling of LX-17 Under Isentropic Compression  

SciTech Connect

Mesoscale simulations of LX-17 incorporating different equilibrium mixture models were used to investigate the unreacted equation-of-state (UEOS) of TATB. Candidate TATB UEOS were calculated using the equilibrium mixture models and benchmarked with mesoscale simulations of isentropic compression experiments (ICE). X-ray computed tomography (XRCT) data provided the basis for initializing the simulations with realistic microstructural details. Three equilibrium mixture models were used in this study. The single constituent with conservation equations (SCCE) model was based on a mass-fraction weighted specific volume and the conservation of mass, momentum, and energy. The single constituent equation-of-state (SCEOS) model was based on a mass-fraction weighted specific volume and the equation-of-state of the constituents. The kinetic energy averaging (KEA) model was based on a mass-fraction weighted particle velocity mixture rule and the conservation equations. The SCEOS model yielded the stiffest TATB EOS (0.121{micro} + 0.4958{micro}{sup 2} + 2.0473{micro}{sup 3}) and, when incorporated in mesoscale simulations of the ICE, demonstrated the best agreement with VISAR velocity data for both specimen thicknesses. The SCCE model yielded a relatively more compliant EOS (0.1999{micro}-0.6967{micro}{sup 2} + 4.9546{micro}{sup 3}) and the KEA model yielded the most compliant EOS (0.1999{micro}-0.6967{micro}{sup 2}+4.9546{micro}{sup 3}) of all the equilibrium mixture models. Mesoscale simulations with the lower density TATB adiabatic EOS data demonstrated the least agreement with VISAR velocity data.

Springer, H K; Willey, T M; Friedman, G; Fried, L E; Vandersall, K S; Baer, M R

2010-03-06T23:59:59.000Z

19

Processing of cloud condensation nuclei by collision-coalescence in a mesoscale model  

E-Print Network (OSTI)

The Naval Research Laboratory's Coupled Ocean-Atmosphere Mesoscale Prediction System (COAMPS) is employed to explore the relative importance of source, sink, and transport processes in producing an accurate forecast of the ...

Mechem, David B.; Robinson, Paul C.; Kogan, Yefim L.

2006-09-26T23:59:59.000Z

20

Mesoscale model cloud scheme assessment using satellite observations Jean-Pierre Chaboureau, Jean-Pierre Cammas, Patrick J. Mascart, and Jean-Pierre Pinty  

E-Print Network (OSTI)

of the convective towers in the generation of synthetic BT maps. INDEX TERMS: 3329 Meteorology and Atmospheric-scale cloudiness in the model. A similar test conducted on the ice water and the liquid water paths confirms Dynamics: Mesoscale meteorology; 3360 Meteorology and Atmospheric Dynamics: Remote sensing; 3354

Chaboureau, Jean-Pierre

Note: This page contains sample records for the topic "atmospheric mesoscale model" 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

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

E-Print Network (OSTI)

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

22

Simulating Typhoon Floods with Gauge Data and Mesoscale-Modeled Rainfall in a Mountainous Watershed  

Science Journals Connector (OSTI)

A physically based distributed hydrological model was applied to simulate typhoon floods over a mountainous watershed in Taiwan. The meteorological forcings include the observed gauge rainfall data and the predicted rainfall data from a mesoscale ...

Ming-Hsu Li; Ming-Jen Yang; Ruitang Soong; Hsiao-Ling Huang

2005-06-01T23:59:59.000Z

23

Impacts on ocean heat from transient mesoscale eddies in a hierarchy of climate models  

Science Journals Connector (OSTI)

We characterize impacts on heat in the ocean climate system from transient ocean mesoscale eddies. Our tool is a suite of centennial-scale 1990 radiatively forced numerical climate simulations from three GFDL coupled models comprising the CM2-O ...

Stephen M. Griffies; Michael Winton; Whit G. Anderson; Rusty Benson; Thomas L. Delworth; Carolina O. Dufour; John P. Dunne; Paul Goddard; Adele k. Morrison; Anthony Rosati; Andrew T. Wittenberg; Jianjun Yin; Rong Zhang

24

Heuristic correction of wind speed mesoscale models simulations for wind farms prospecting and micrositing  

Science Journals Connector (OSTI)

Abstract The distribution of surface-level wind speeds over a given area is important information that is related to several processes in wind farm prospecting, design and micrositing. This information is often obtained from simulations using mesoscale models that take variables from global models as starting points. Improved outputs from mesoscale models can lead to reduced error compared to real wind speeds in the study area if in situ wind speed measurements are available. In this paper, we present several techniques to correct surface wind speed simulations from mesoscale models using data from measuring stations in wind farms. Specifically, we propose different heuristic corrections of the outputs from mesoscale models by means of surface fitting between the Weibull parameters of the wind speed series (from the mesoscale model) and those from the measuring stations (real wind speed) in the wind farm. The proposed methodology has direct applications in wind farm design, site prospection and micrositing. The good performance of our method is evident in the more accurate surface wind speeds obtained from mesoscale models in two wind farm prospection sites in Spain, where several measuring towers are installed.

B. Saavedra-Moreno; S. Salcedo-Sanz; C. Casanova-Mateo; J.A. Portilla-Figueras; L. Prieto

2014-01-01T23:59:59.000Z

25

Spatial-temporal mesoscale modelling of rainfall intensity using gage and radar data  

E-Print Network (OSTI)

Spatial-temporal mesoscale modelling of rainfall intensity using gage and radar data Montserrat fields. Doppler radar data offer better spatial and temporal coverage, but Doppler radar measures values. We use spatial logistic regression to model the probability of rain for both sources of data

Reich, Brian J.

26

Resolved Turbulence Characteristics in Large-Eddy Simulations Nested within Mesoscale Simulations Using the Weather Research and Forecasting Model  

Science Journals Connector (OSTI)

One-way concurrent nesting within the Weather Research and Forecasting Model (WRF) is examined for conducting large-eddy simulations (LES) nested within mesoscale simulations. Wind speed, spectra, and resolved turbulent stresses and turbulence ...

Jeff Mirocha; Branko Kosovi?; Gokhan Kirkil

2014-02-01T23:59:59.000Z

27

The effect of shear on heat budgets in a simulated Mesoscale Convective System  

E-Print Network (OSTI)

The evolution and structure of simulated Mesoscale Convective Systems (MCS) were examined using the Collaborative Model for Multiscale Atmospheric Simulations. Three numerical simulations were performed, with the amount of vertical wind shear...

Shaw, Justin David

2000-01-01T23:59:59.000Z

28

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

E-Print Network (OSTI)

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

Xu, L.

29

Tests of an Ensemble Kalman Filter for Mesoscale and Regional-Scale Data Assimilation. Part II: Imperfect Model Experiments  

E-Print Network (OSTI)

degraded). As in Part I, where the perfect model assumption was utilized, most analysis error reduction of significant model errors due to physical parameterizations by assimilating synthetic sounding and surfaceTests of an Ensemble Kalman Filter for Mesoscale and Regional-Scale Data Assimilation. Part II

Meng, Zhiyong

30

MESOSCALE SIMULATION OF ATMOSPHERIC RESPONSE TO CHAOS TERRAIN FORMATION. , S.C.R. Rafkin2  

E-Print Network (OSTI)

(kite@berkeley.edu), 2 Department of Space Studies, Southwest Research Institute, Boulder, Colorado associated with chaos terrain formation may mobilize sand and perhaps gravel, but not boulders. Model, momentum and moisture are parameter- ized using a Monin-Obukhov scheme. Boundary conditions: We flooded

Kite, Edwin

31

Cloud shading retrieval and assimilation in a satellite-model coupled mesoscale analysis system  

SciTech Connect

A retrieval-assimilation method has been developed as a quantitative means to exploit the information in satellite imagery regarding shading of the ground by clouds, as applied to mesoscale weather analysis. Cloud radiative parameters are retrieved from satellite visible image data and used, along with parameters computed by a numerical model, to control the model's computation of downward radiative fluxes at the ground. These fluxes influence the analysis of ground surface temperatures under clouds. The method is part of a satellite-model coupled four-dimensional analysis system that merges information from visible image data in cloudy areas with infrared sounder data in clear areas, where retrievals of surface temperatures and water vapor concentrations are assimilated. The substantial impact of shading on boundary-layer development and mesoscale circulations was demonstrated in simulations, and the value of assimilating shading retrievals was demonstrated with a case study and with a simulated analysis that included the effects of several potential sources of error. The case study was performed in the northwestern Texas area, where convective cloud development was influenced by the shading effects of a persistent region of stratiform cloud cover. Analyses that included shading retrieval assimilation had consistently smaller shelter-height temperature errors than analyses without shading retrievals. When clear-area surface temperature retrievals from sounder data were analyzed along with cloudy-area shading retrievals, the contrast in heating between the shaded and clear parts of the domain led to large variations in analyzed boundary-layer depths and had a modest impact on analyzed wind flow. The analyzed locations of upward vertical motion corresponded roughly to areas of convective cloud development observed in satellite imagery. 29 refs., 17 figs., 2 tabs.

Lipton, A.E. (Phillips Lab., Hanscom AFB, MA (United States))

1993-11-01T23:59:59.000Z

32

A soil moisture assimilation scheme using satellite-retrieved skin temperature in meso-scale weather forecast model  

Science Journals Connector (OSTI)

A thermodynamically consistent soil moisture assimilation scheme for clear sky and snow free conditions has been developed for the meso-scale modeling system in the Arctic region by using satellite-derived skin temperatures. Parallel control and sensitivity modeling experiments were designed and their results demonstrated that the assimilation scheme successfully improves the soil moistures that were deliberately perturbed initially, indicating capability of the scheme to correct bias in the soil moisture initialization. Moreover, the resultant benefit of this assimilation scheme does not only lie in the improvement of soil moisture; the skin temperature also consequently exhibits improvements in a thermodynamic consistency. A real application of the assimilation scheme with satellite-retrieved skin temperature exhibited noticeable positive impacts on the modeling simulation and weather forecast; the model obviously captured meso-scale features of soil moistures as well as the skin temperatures. The warming tendency bias in original model simulations was removed to a considerable extent by this assimilation scheme.

Jing Zhang; Xiangdong Zhang

2010-01-01T23:59:59.000Z

33

Sensitivity of the Simulated Distributions of Water Masses, CFCs, and Bomb 14C to Parameterizations of Mesoscale Tracer Transports in a Model of the North Pacific  

Science Journals Connector (OSTI)

A basinwide ocean general circulation model of the North Pacific Ocean is used to study the sensitivity of the simulated distributions of water masses, chlorofluorocarbons (CFCs), and bomb carbon-14 isotope (14C) to parameterizations of mesoscale ...

Yongfu Xu; Shigeaki Aoki; Koh Harada

2006-03-01T23:59:59.000Z

34

Improving an Accuracy of ANN-Based Mesoscale-Microscale Coupling Model by Data Categorization: With Application to Wind Forecast for Offshore and Complex Terrain Onshore Wind Farms  

Science Journals Connector (OSTI)

The ANN-based mesoscale-microscale coupling model forecasts wind speed and wind direction with high accuracy for wind parks located in complex terrain onshore, yet some weather regimes remains unresolved and f...

Alla Sapronova; Catherine Meissner…

2014-01-01T23:59:59.000Z

35

The reduction of plankton biomass induced by mesoscale stirring: a modeling study in the Benguela upwelling  

E-Print Network (OSTI)

Recent studies, both based on remote sensed data and coupled models, showed a reduction of biological productivity due to vigorous horizontal stirring in upwelling areas. In order to better understand this phenomenon, we consider a system of oceanic flow from the Benguela area coupled with a simple biogeochemical model of Nutrient-Phyto-Zooplankton (NPZ) type. For the flow three different surface velocity fields are considered: one derived from satellite altimetry data, and the other two from a regional numerical model at two different spatial resolutions. We compute horizontal particle dispersion in terms of Lyapunov Exponents, and analyzed their correlations with phytoplankton concentrations. Our modelling approach confirms that in the south Benguela there is a reduction of biological activity when stirring is increased. Two-dimensional offshore advection and latitudinal difference in Primary Production, also mediated by the flow, seem to be the dominant processes involved. We estimate that mesoscale processes are responsible for 30 to 50% of the offshore fluxes of biological tracers. In the northern area, other factors not taken into account in our simulation are influencing the ecosystem. We suggest explanations for these results in the context of studies performed in other eastern boundary upwelling areas.

Ismael Hernández-Carrasco; Vincent Rossi; Emilio Hernández-García; Veronique Garçon; Cristóbal López

2013-11-05T23:59:59.000Z

36

A Coupled Model Study on the Formation and Dissipation of Sea Fogs  

Science Journals Connector (OSTI)

This study examined the impact of air–sea coupling using a coupled atmosphere–ocean modeling system consisting of the Coupled Ocean–Atmosphere Mesoscale Prediction System as the atmospheric component and the Regional Ocean Modeling System as the ...

Ki-Young Heo; Kyung-Ja Ha

2010-04-01T23:59:59.000Z

37

The Southern Ocean in the Coupled Model Intercomparison Project phase 5  

Science Journals Connector (OSTI)

...atmosphere and ocean (although the ocean remains too coarse to permit mesoscale eddies), a larger proportion of full Earth system models (ESMs) resolving biogeochemical cycles, the inclusion of atmospheric ozone in all models and more complete atmospheric...

2014-01-01T23:59:59.000Z

38

Poster Sessions J. Dudhia Mesoscale and Microscale Meteorology Division  

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

J. Dudhia J. Dudhia Mesoscale and Microscale Meteorology Division National Center for Atmospheric Research Boulder, CO 80307-3000 Introduction The concept of an Integrated Data Assimilation and Sounding System (IDASS) ensures that the needs of data collection are partly determined by the requirements of an assimilating mesoscale model. Hence, the sounding strategy is geared towards allowing the model to do the best possible job in representing the atmosphere over CART sites, for example. It is not clear a priori what density of coverage or types of data are required for a good simulation. In this work, we address the problem of determining the impact of varying the density of coverage of an idea! network by purely numerical experimentation. We use one model run to provide data and another independent run to assimilate it.

39

Chemical modeling of exoplanet atmospheres  

E-Print Network (OSTI)

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

Venot, Olivia

2014-01-01T23:59:59.000Z

40

Coupling between the University of California, Davis, Advanced Canopy–Atmosphere–Soil Algorithm (ACASA) and MM5: Preliminary Results for July 1998 for Western North America  

Science Journals Connector (OSTI)

The University of California, Davis, Advanced Canopy–Atmosphere–Soil Algorithm (ACASA) is coupled to the fifth-generation Pennsylvania State University–National Center for Atmospheric Research (NCAR) Mesoscale Model (MM5) as a land surface ...

R. David Pyles; Bryan C. Weare; Kyaw Tha Paw U; William Gustafson

2003-05-01T23:59:59.000Z

Note: This page contains sample records for the topic "atmospheric mesoscale model" 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

MESOI Version 2. 0: an interactive mesoscale Lagrangian puff dispersion model with deposition and decay  

SciTech Connect

MESOI Version 2.0 is an interactive Lagrangian puff model for estimating the transport, diffusion, deposition and decay of effluents released to the atmosphere. The model is capable of treating simultaneous releases from as many as four release points, which may be elevated or at ground-level. The puffs are advected by a horizontal wind field that is defined in three dimensions. The wind field may be adjusted for expected topographic effects. The concentration distribution within the puffs is initially assumed to be Gaussian in the horizontal and vertical. However, the vertical concentration distribution is modified by assuming reflection at the ground and the top of the atmospheric mixing layer. Material is deposited on the surface using a source depletion, dry deposition model and a washout coefficient model. The model also treats the decay of a primary effluent species and the ingrowth and decay of a single daughter species using a first order decay process. This report is divided into two parts. The first part discusses the theoretical and mathematical bases upon which MESOI Version 2.0 is based. The second part contains the MESOI computer code. The programs were written in the ANSI standard FORTRAN 77 and were developed on a VAX 11/780 computer. 43 references, 14 figures, 13 tables.

Ramsdell, J.V.; Athey, G.F.; Glantz, C.S.

1983-11-01T23:59:59.000Z

42

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

43

Model Atmospheres for Low Field Neutron Stars  

E-Print Network (OSTI)

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

Mohan Rajagopal; Roger Romani

1995-10-19T23:59:59.000Z

44

Impact of Agricultural Practice on Regional Climate in a CoupledLand Surface Mesoscale Model  

SciTech Connect

The land surface has been shown to form strong feedbacks with climate due to linkages between atmospheric conditions and terrestrial ecosystem exchanges of energy, momentum, water, and trace gases. Although often ignored in modeling studies, land management itself may form significant feedbacks. Because crops are harvested earlier under drier conditions, regional air temperature, precipitation, and soil moisture, for example, affect harvest timing, particularly of rain-fed crops. This removal of vegetation alters the land surface characteristics and may, in turn, affect regional climate. We applied a coupled climate(MM5) and land-surface (LSM1) model to examine the effects of early and late winter wheat harvest on regional climate in the Department of Energy Atmospheric Radiation Measurement (ARM) Climate Research Facility in the Southern Great Plains, where winter wheat accounts for 20 percent of the land area. Within the winter wheat region, simulated 2 m air temperature was 1.3 C warmer in the Early Harvest scenario at mid-day averaged over the two weeks following harvest. Soils in the harvested area were drier and warmer in the top 10 cm and wetter in the 10-20 cm layer. Midday soils were 2.5 C warmer in the harvested area at mid-day averaged over the two weeks following harvest. Harvest also dramatically altered latent and sensible heat fluxes. Although differences between scenarios diminished once both scenarios were harvested, the short-term impacts of land management on climate were comparable to those from land cover change demonstrated in other studies.

Cooley, H.S.; Riley, W.J.; Torn, M.S.; He, Y.

2004-07-01T23:59:59.000Z

45

Performance Engineering in the Community Atmosphere Model  

SciTech Connect

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

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

2006-05-30T23:59:59.000Z

46

Use of ARM observations and numerical models to determine radiative and latent heating profiles of mesoscale convective systems for general circulation models  

SciTech Connect

This three-year project, in cooperation with Professor Bob Houze at University of Washington, has been successfully finished as planned. Both ARM (the Atmospheric Radiation Measurement Program) data and cloud-resolving model (CRM) simulations were used to identify the water budgets of clouds observed in two international field campaigns. The research results achieved shed light on several key processes of clouds in climate change (or general circulation models), which are summarized below. 1. Revealed the effect of mineral dust on mesoscale convective systems (MCSs) Two international field campaigns near a desert and a tropical coast provided unique data to drive and evaluate CRM simulations, which are TWP-ICE (the Tropical Warm Pool International Cloud Experiment) and AMMA (the African Monsoon Multidisciplinary Analysis). Studies of the two campaign data were contrasted, revealing that much mineral dust can bring about large MCSs via ice nucleation and clouds. This result was reported as a PI presentation in the 3rd ASR Science Team meeting held in Arlington, Virginia in March 2012. A paper on the studies was published in the Journal of the Atmospheric Sciences (Zeng et al. 2013). 2. Identified the effect of convective downdrafts on ice crystal concentration Using the large-scale forcing data from TWP-ICE, ARM-SGP (the Southern Great Plains) and other field campaigns, Goddard CRM simulations were carried out in comparison with radar and satellite observations. The comparison between model and observations revealed that convective downdrafts could increase ice crystal concentration by up to three or four orders, which is a key to quantitatively represent the indirect effects of ice nuclei, a kind of aerosol, on clouds and radiation in the Tropics. This result was published in the Journal of the Atmospheric Sciences (Zeng et al. 2011) and summarized in the DOE/ASR Research Highlights Summaries (see http://www.arm.gov/science/highlights/RMjY5/view). 3. Used radar observations to evaluate model simulations In cooperation with Profs. Bob Houze at University of Washington and Steven Rutledge at Colorado State University, numerical model results were evaluated with observations from W- and C-band radars and CloudSat/TRMM satellites. These studies exhibited some shortcomings of current numerical models, such as too little of thin anvil clouds, directing the future improvement of cloud microphysics parameterization in CRMs. Two papers of Powell et al (2012) and Zeng et al. (2013), summarizing these studies, were published in the Journal of the Atmospheric Sciences. 4. Analyzed the water budgets of MCSs Using ARM data from TWP-ICE, ARM-SGP and other field campaigns, the Goddard CRM simulations were carried out to analyze the water budgets of clouds from TWP-ICE and AMMA. The simulations generated a set of datasets on clouds and radiation, which are available http://cloud.gsfc.nasa.gov/. The cloud datasets were available for modelers and other researchers aiming to improve the representation of cloud processes in multi-scale modeling frameworks, GCMs and climate models. Special datasets, such as 3D cloud distributions every six minutes for TWP-ICE, were requested and generated for ARM/ASR investigators. Data server records show that 86,206 datasets were downloaded by 120 users between April of 2010 and January of 2012. 5. MMF simulations The Goddard MMF (multi-scale modeling framework) has been improved by coupling with the Goddard Land Information System (LIS) and the Goddard Earth Observing System Model, Version 5 (GOES5). It has also been optimized on NASA HEC supercomputers and can be run over 4000 CPUs. The improved MMF with high horizontal resolution (1 x 1 degree) is currently being applied to cases covering 2005 and 2006. The results show that the spatial distribution pattern of precipitation rate is well simulated by the MMF through comparisons with satellite retrievals from the CMOPRH and GPCP data sets. In addition, the MMF results were compared with three reanalyses (MERRA, ERA-Interim and CFSR). Although the MMF tends

Tao, Wei-Kuo; Houze, Robert, A., Jr.; Zeng, Xiping

2013-03-14T23:59:59.000Z

47

Visualizing Storms from NCAR's Atmosphere Model at NERSC  

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

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

48

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

E-Print Network (OSTI)

to local SST perturbations decreases rapidly with height to near-zero at 150-300m. The simulated wind speed of local SST perturbations, and the orientation of the surface wind to the SST gradient. #12;3 1. Introduction Positive correlations of local surface wind anomalies with sea surface temperature (SST) anomalies

49

Stereographic displays of atmospheric model data  

Science Journals Connector (OSTI)

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

Mary desJardins; A. Frederick Hasler

1980-07-01T23:59:59.000Z

50

A Community Atmosphere Model with Superparameterized Clouds  

SciTech Connect

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

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

2013-06-18T23:59:59.000Z

51

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

52

Recipes for Correcting the Impact of Effective Mesoscale Resolution on the Estimation of Extreme Winds  

Science Journals Connector (OSTI)

Extreme winds derived from simulations using mesoscale models are underestimated because of the effective spatial and temporal resolutions. This is reflected in the spectral domain as an energy deficit in the mesoscale range. The energy deficit ...

Xiaoli Guo Larsén; Søren Ott; Jake Badger; Andrea N. Hahmann; Jakob Mann

2012-03-01T23:59:59.000Z

53

Self-Assembly of Mesoscale Isomers: The Role of Pathways and Degrees of Freedom  

E-Print Network (OSTI)

Self-Assembly of Mesoscale Isomers: The Role of Pathways and Degrees of Freedom Shivendra Pandey1 geometric path sampling and a mesoscale experimental model to investigate the self-assembly of a model. Citation: Pandey S, Johnson D, Kaplan R, Klobusicky J, Menon G, et al. (2014) Self-Assembly of Mesoscale

Menon, Govind

54

Multiphase Modeling of Flow, Transport, and Biodegradation in a Mesoscale Landfill Bioreactor  

E-Print Network (OSTI)

1179. Popov, V. ; Power, H. Landfill emission of gases intoC.M. T2LBM Version 1.0: Landfill bioreactor model forand recovery from landfills, Ann Arbor Science Publishers,

Oldenburg, Curtis M.; Borglin, Sharon E.; Hazen, Terry C.

2002-01-01T23:59:59.000Z

55

Development and validation of a vertically two-dimensional mesoscale numerical model  

E-Print Network (OSTI)

because the model is dry. The equations are as follows: dv " ? 1 1 d dv f k X V ? ? Vp ? g Vz + ? ~ ? (pK ? ), (2) dt P pH ds m ds pgH do dn d o + 'it ~ pV + ? (ns) + p V ~ VH = 0 dt ds P H (4) dT . H Q sg ? + d t C p C p pRT The symbols... of the model. The remaining variables have been previously defined. 15 The finite difference equations are as follows: ~ H (o V (i, k) = H(i+1) * ( p(i+1, k) + p(i, k) ) * u(i+1, k) ? H(i) * ( p(i, k) + p (i-l, k) ) * u(i, k) / ( 2 a DX ) = DV(i k) (I...

Walters, Michael Kent

2012-06-07T23:59:59.000Z

56

Lipid-Based Nanodiscs as Models for Studying Mesoscale Coalescence A Transport Limited Case  

SciTech Connect

Lipid-based nanodiscs (bicelles) are able to form in mixtures of long- and short-chain lipids. Initially, they are of uniform size but grow upon dilution. Previously, nanodisc growth kinetics have been studied using time-resolved small angle neutron scattering (SANS), a technique which is not well suited for probing their change in size immediately after dilution. To address this, we have used dynamic light scattering (DLS), a technique which permits the collection of useful data in a short span of time after dilution of the system. The DLS data indicate that the negatively charged lipids in nanodiscs play a significant role in disc stability and growth. Specifically, the charged lipids are most likely drawn out from the nanodiscs into solution, thereby reducing interparticle repulsion and enabling the discs to grow. We describe a population balance model, which takes into account Coulombic interactions and adequately predicts the initial growth of nanodiscs with a single parameter i.e., surface potential. The results presented here strongly support the notion that the disc coalescence rate strongly depends on nanoparticle charge density. The present system containing low-polydispersity lipid nanodiscs serves as a good model for understanding how charged discoidal micelles coalesce.

Hu, Andrew [University of Connecticut, Storrs; Fan, Tai-Hsi [University of Connecticut, Storrs; Katsaras, John [ORNL; Xia, Yan [University of Connecticut, Storrs; Li, Ming [University of Connecticut, Storrs; Nieh, Mu-Ping [University of Connecticut, Storrs

2014-01-01T23:59:59.000Z

57

Modeling atmospheric deposition using a stochastic transport model  

SciTech Connect

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

Buckley, R.L.

1999-12-17T23:59:59.000Z

58

Atmospheric Dispersion Modeling in Safety Analyses; GENII  

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

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

59

Parallel computing in atmospheric chemistry models  

SciTech Connect

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

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

1996-02-01T23:59:59.000Z

60

Nesting large-eddy simulations within mesoscale simulations for wind energy applications  

SciTech Connect

With increasing demand for more accurate atmospheric simulations for wind turbine micrositing, for operational wind power forecasting, and for more reliable turbine design, simulations of atmospheric flow with resolution of tens of meters or higher are required. These time-dependent large-eddy simulations (LES), which resolve individual atmospheric eddies on length scales smaller than turbine blades and account for complex terrain, are possible with a range of commercial and open-source software, including the Weather Research and Forecasting (WRF) model. In addition to 'local' sources of turbulence within an LES domain, changing weather conditions outside the domain can also affect flow, suggesting that a mesoscale model provide boundary conditions to the large-eddy simulations. Nesting a large-eddy simulation within a mesoscale model requires nuanced representations of turbulence. Our group has improved the Weather and Research Forecasting model's (WRF) LES capability by implementing the Nonlinear Backscatter and Anisotropy (NBA) subfilter stress model following Kosovic (1997) and an explicit filtering and reconstruction technique to compute the Resolvable Subfilter-Scale (RSFS) stresses (following Chow et al, 2005). We have also implemented an immersed boundary method (IBM) in WRF to accommodate complex terrain. These new models improve WRF's LES capabilities over complex terrain and in stable atmospheric conditions. We demonstrate approaches to nesting LES within a mesoscale simulation for farms of wind turbines in hilly regions. Results are sensitive to the nesting method, indicating that care must be taken to provide appropriate boundary conditions, and to allow adequate spin-up of turbulence in the LES domain.

Lundquist, J K; Mirocha, J D; Chow, F K; Kosovic, B; Lundquist, K A

2008-09-08T23:59:59.000Z

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61

Atmospheric model intercomparison project: Monsoon simulations  

SciTech Connect

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

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

1994-06-01T23:59:59.000Z

62

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

63

Mesoscale Eddy Energy Locality in an Idealized Ocean Model IAN GROOMS, LOUIS-PHILIPPE NADEAU, AND K. SHAFER SMITH  

E-Print Network (OSTI)

. SHAFER SMITH Center for Atmosphere Ocean Science, Courant Institute of Mathematical Sciences, New York

Smith, K. Shafer

64

Atmospheric transmittance model for photosynthetically active radiation  

SciTech Connect

A parametric model of the atmospheric transmittance in the PAR band is presented. The model can be straightforwardly applied for calculating the beam, diffuse and global components of the PAR solar irradiance. The required inputs are: air pressure, ozone, water vapor and nitrogen dioxide column content, Ångström'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

65

Atmospheric Chemistry, Modeling, and Biogeochemistry of Mercury  

E-Print Network (OSTI)

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

66

Testing a Detailed Biophysical Parameterization for Land–Air Exchange in a High-Resolution Boundary-Layer Model  

Science Journals Connector (OSTI)

In order to properly model the influence of land surface properties on mesoscale atmospheric phenomena, it is important to include physically realistic parameterizations of major biophysical processes involved. The primary influence of the ...

S. Argentini; P. J. Wetzel; V. M. Karyampudi

1992-02-01T23:59:59.000Z

67

Use of ARM observations and numerical models to determine radiative and latent heating profiles of mesoscale convective systems for general circulation models  

SciTech Connect

We examined cloud radar data in monsoon climates, using cloud radars at Darwin in the Australian monsoon, on a ship in the Bay of Bengal in the South Asian monsoon, and at Niamey in the West African monsoon. We followed on with a more in-depth study of the continental MCSs over West Africa. We investigated whether the West African anvil clouds connected with squall line MCSs passing over the Niamey ARM site could be simulated in a numerical model by comparing the observed anvil clouds to anvil structures generated by the Weather Research and Forecasting (WRF) mesoscale model at high resolution using six different ice-phase microphysical schemes. We carried out further simulations with a cloud-resolving model forced by sounding network budgets over the Niamey region and over the northern Australian region. We have devoted some of the effort of this project to examining how well satellite data can determine the global breadth of the anvil cloud measurements obtained at the ARM ground sites. We next considered whether satellite data could be objectively analyzed to so that their large global measurement sets can be systematically related to the ARM measurements. Further differences were detailed between the land and ocean MCS anvil clouds by examining the interior structure of the anvils with the satellite-detected the CloudSat Cloud Profiling Radar (CPR). The satellite survey of anvil clouds in the Indo-Pacific region was continued to determine the role of MCSs in producing the cloud pattern associated with the MJO.

Houze, Jr., Robert A. [University of Washington Dept. of Atmospheric Sciences

2013-11-13T23:59:59.000Z

68

Momentum transport processes in the stratiform regions of mesoscale convective systems over the western Pacific warm pool  

E-Print Network (OSTI)

Momentum transport by the stratiform components of mesoscale convective systems (MCSs) during the Tropical Ocean–Global Atmosphere Coupled Ocean–Atmosphere Response Experiment in December 1992 is investigated using a ...

Mechem, David B.; Chen, Shuyi S.; Houze, Robert A. Jr.

2006-04-01T23:59:59.000Z

69

Mesoscale hybrid calibration artifact  

DOE Patents (OSTI)

A mesoscale calibration artifact, also called a hybrid artifact, suitable for hybrid dimensional measurement and the method for make the artifact. The hybrid artifact has structural characteristics that make it suitable for dimensional measurement in both vision-based systems and touch-probe-based systems. The hybrid artifact employs the intersection of bulk-micromachined planes to fabricate edges that are sharp to the nanometer level and intersecting planes with crystal-lattice-defined angles.

Tran, Hy D. (Albuquerque, NM); Claudet, Andre A. (Albuquerque, NM); Oliver, Andrew D. (Waltham, MA)

2010-09-07T23:59:59.000Z

70

On Adaptive Mesh Refinement for Atmospheric Pollution Models  

E-Print Network (OSTI)

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

Sandu, Adrian

71

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

72

Mesoscale Structure of Trade Wind Convection over Puerto Rico: Composite Observations and Numerical Simulation  

Science Journals Connector (OSTI)

We examine the mesoscale structure of the atmospheric boundary layer (ABL), low-level circulation, and trade wind convection over the sub-tropical island of Puerto Rico in mid-summer. Shallow afternoon thunder...

Mark R. Jury; Sen Chiao; Eric W. Harmsen

2009-08-01T23:59:59.000Z

73

MESOSCALE SIMULATIONS OF POWDER COMPACTION  

SciTech Connect

Mesoscale 3D simulations of shock compaction of metal and ceramic powders have been performed with an Eulerian hydrocode GEODYN. The approach was validated by simulating a well-characterized shock compaction experiment of a porous ductile metal. Simulation results using the Steinberg material model and handbook values for solid 2024 aluminum showed good agreement with experimental compaction curves and wave profiles. Brittle ceramic materials are not as well studied as metals, so a simple material model for solid ceramic (tungsten carbide) has been calibrated to match experimental compaction curves. Direct simulations of gas gun experiments with ceramic powders have been performed and showed good agreement with experimental data. The numerical shock wave profile has same character and thickness as that measured experimentally using VISAR. The numerical results show reshock states above the single-shock Hugoniot line as observed in experiments. We found that for good quantitative agreement with experiments 3D simulations are essential.

Lomov, Ilya; Fujino, Don; Antoun, Tarabay; Liu, Benjamin [Lawrence Livermore National Laboratory, P. O. Box 808, Livermore CA 94551 (United States)

2009-12-28T23:59:59.000Z

74

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

75

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

Science Journals Connector (OSTI)

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

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

2012-01-01T23:59:59.000Z

76

HIGH-RESOLUTION ATMOSPHERIC ENSEMBLE MODELING AT SRNL  

SciTech Connect

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

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

2011-05-10T23:59:59.000Z

77

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

78

ARM - Publications: Science Team Meeting Documents: Evaluation of mesoscale  

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

Evaluation of mesoscale model cloud simulations of the March 2000 IOP Evaluation of mesoscale model cloud simulations of the March 2000 IOP Tselioudis, George NASA/Goddard Institute for Space Studies A suite of mesoscale models was used to produce month-long runs of the March 2000 SGP IOP. The model cloud fields were evaluated against satellite and in-situ observations, using both monthly statistics of cloud properties and instantaneous cloud property distributions. It was found that compared to satellite retrievals models tend to overestimate cloud optical thickness in all dynamic regimes. The reasons for the differences in satellite and model cloud fields were investigated. Preliminary results indicate that the large model optical depths may be caused by an overestimate of cloud ice water amounts in the model simulations. Part of the differences, however,

79

Mesoscale disturbances in the tropical stratosphere excited by convection: Observations and effects on the stratospheric momentum budget  

SciTech Connect

The importance of the momentum flux of topographically generated mesoscale gravity waves to the extratropical middle atmosphere circulation has been well established for over a decade. Estimates of the zonal forcing due to tropical mesoscale gravity waves, however, are hampered by lack of data on their primarily convective sources. The advent of aircraft measurements over tropical convective systems now makes such estimates possible without the use of ad hoc assumptions about amplitudes and phase speeds. Aircraft measurements from NASA's 1980 Panama and 1987 STEP/Australia Missions show that convectively generated disturbances observed just above the tropopause have horizontal scales comparable to those of the underlying anvils (about 50--100 km) with peak-to-peak isentropic surface variations of about 300--400 m. Satellite imagery of tropical anvil evolution indicates a typical lifetime of about five hours. Assuming that each convective system's impact on the stratosphere can be modeled as a time-dependent [open quotes]mountain[close quotes] with the preceding spatial and time scales, the excited spectrum of gravity waves can be calculated. A suitable quasi-linear wave-mean flow interaction parameterization and satellite-derived cloud area statistics can then be used to evaluate the zonal acceleration as a function of altitude induced by gravity waves from mesoscale convective systems. The results indicate maximum westerly accelerations due to breaking mesoscale gravity waves of almost 0.4 m s[sup [minus]1]/day in the upper stratosphere (in the region of the semiannual oscillation) during September, comparable to but probably smaller than the accelerations induced by planetary-scale Kelvin waves. Calculated easterly accelerations due to breaking mesoscale gravity waves in the QBO region below 35 km are smaller, accounting for about 10% of the required zonal acceleration. 35 refs., 14 figs., 1 tab.

Pfister, L.; Scott, S.; Loewenstein, M. (NASA/Ames Research Center, Moffett Field, CA (United States)); Bowen, S. (San Jose State Univ., CA (United States)); Legg, M. (Synernet, Fremont, CA (United States))

1993-04-15T23:59:59.000Z

80

Modeling the effects of atmospheric emissions on groundwater composition  

SciTech Connect

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

Brown, T.J.

1994-12-31T23:59:59.000Z

Note: This page contains sample records for the topic "atmospheric mesoscale model" 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

FOAM: Fast Ocean Atmosphere Model | Argonne National Laboratory  

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

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

82

E-Print Network 3.0 - atmospheric sciences program Sample Search...  

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

Summary: of the atmospheric sciences (relate to program outcome a, b, c, and d) Meteo 361 Fundamentals of Mesoscale Weather... atmospheric science manuscripts (relate to program...

83

A STUDY OF ICE ACCUMULATION AND STABILITY IN MARTIAN CRATERS UNDER PAST ORBITAL CONDITIONS USING THE LMD MESOSCALE MODEL.  

E-Print Network (OSTI)

constraints Methodological approach Better understand the local distribution of gullies and glaciers; Blowing snow = snow coming from other areas and brought by winds. Ice sublimation: · High surface temperature, low relative humidity in the lower atmosphere, high wind strength; · High wind erosion. Figure 1

Madeleine, Jean-Baptiste

84

Numerical Simulation of the Meso-? Scale Structure and Evolution of the 1977 Johnstown Flood. Part II: Inertially Stable Warm-Core Vortex and the Mesoscale Convective Complex  

Science Journals Connector (OSTI)

A mesoscale warm-core vortex associated with the mesoscale convective complex (MCC) that produced the 1977 Johnstown flood is examined using a three-dimensional nested-grid model simulation of the flood episode. In the simulation, the vortex ...

Da-Lin Zhang; J. Michael Fritsch

1987-09-01T23:59:59.000Z

85

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

Science Journals Connector (OSTI)

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

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

86

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

87

Predicting mesh density for adaptive modelling of the global atmosphere  

Science Journals Connector (OSTI)

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

2009-01-01T23:59:59.000Z

88

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

89

Mesoscale Simulations of Power Compaction  

SciTech Connect

Mesoscale 3D simulations of metal and ceramic powder compaction in shock waves have been performed with an Eulerian hydrocode GEODYN. The approach was validated by simulating shock compaction of porous well-characterized ductile metal using Steinberg material model. Results of the simulations with handbook values for parameters of solid 2024 aluminum have good agreement with experimental compaction curves and wave profiles. Brittle ceramic materials are not so well studied as metals, so material model for ceramic (tungsten carbide) has been fitted to shock compression experiments of non-porous samples and further calibrated to match experimental compaction curves. Direct simulations of gas gun experiments with ceramic powder have been performed and showed good agreement with experimental data. Numerical shock wave profile has same character and thickness as measured with VISAR. Numerical results show reshock states above the single-shock Hugoniot line also observed in experiments. They found that to receive good quantitative agreement with experiment it is essential to perform 3D simulations.

Lomov, I; Fujino, D; Antoun, T; Liu, B

2009-08-06T23:59:59.000Z

90

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

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

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

91

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

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

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

92

Response of a Coupled Ocean–Atmosphere Model to Increasing Atmospheric Carbon Dioxide: Sensitivity to the Rate of Increase  

Science Journals Connector (OSTI)

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

Ronald J. Stouffer; Syukuro Manabe

1999-08-01T23:59:59.000Z

93

Atmospheric Dispersion Model Validation in Low Wind Conditions  

SciTech Connect

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

Sawyer, Patrick

2007-11-01T23:59:59.000Z

94

Tests of an ensemble Kalman filter for mesoscale and regional-scale data assimilation  

E-Print Network (OSTI)

This dissertation examines the performance of an ensemble Kalman filter (EnKF) implemented in a mesoscale model in increasingly realistic contexts from under a perfect model assumption and in the presence of significant model error with synthetic...

Meng, Zhiyong

2007-09-17T23:59:59.000Z

95

Atmospheric Mercury Model Intercomparisons Presentation at  

E-Print Network (OSTI)

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

96

Mesoscale Climatic Simulation of Surface Air Temperature Cooling by Highly  

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

Mesoscale Climatic Simulation of Surface Air Temperature Cooling by Highly Mesoscale Climatic Simulation of Surface Air Temperature Cooling by Highly Reflective Greenhouses in SE Spain Title Mesoscale Climatic Simulation of Surface Air Temperature Cooling by Highly Reflective Greenhouses in SE Spain Publication Type Journal Article Year of Publication 2013 Authors Campra, Pablo, and Dev Millstein Journal Environmental Science & Technology Volume 47 Issue 21 Pagination 12284 - 12290 Date Published 11/2013 ISSN 0013-936X Keywords buildings, Heat Island Group Abstract A long-term local cooling trend in surface air temperature has been monitored at the largest concentration of reflective greenhouses in the world, at the Province of Almeria, SE Spain, associated with a dramatic increase in surface albedo in the area. The availability of reliable long-term climatic field data at this site offers a unique opportunity to test the skill of mesoscale meteorological models describing and predicting the impacts of land use change on local climate. Using the Weather Research and Forecast (WRF) mesoscale model, we have run a sensitivity experiment to simulate the impact of the observed surface albedo change on monthly and annual surface air temperatures. The model output showed a mean annual cooling of 0.25 °C associated with a 0.09 albedo increase, and a reduction of 22.8 W m-2 of net incoming solar radiation at surface. Mean reduction of summer daily maximum temperatures was 0.49 °C, with the largest single-day decrease equal to 1.3 °C. WRF output was evaluated and compared with observations. A mean annual warm bias (MBE) of 0.42 °C was estimated. High correlation coefficients (R2 > 0.9) were found between modeled and observed values. This study has particular interest in the assessment of the potential for urban temperature cooling by cool roofs deployment projects, as well as in the evaluation of mesoscale climatic models performance.

97

Impact of the tropopause temperature on the intensity of tropical cyclones an idealized study using a mesoscale model  

E-Print Network (OSTI)

) models TCs as heat engines, operating29 between the warm ocean and the cold tropopause and converting thermal energy to mechanical30 energy. Variations in the sea surface temperature (SST) have received much

Sobel, Adam

98

Mesoscale Modeling and Validation of Texture Evolution during Asymmetric Rooling and Static Recrystallization of Magnesium Alloy AZ31B  

SciTech Connect

The focus of the present research is to develop an integrated deformation and recrystallization model for magnesium alloys at the microstructural length scale. It is known that in magnesium alloys nucleation of recrystallized grains occurs at various microstructural inhomogeneities such as twins and localized deformation bands. However, there is a need to develop models that can predict the evolution of the grain structure and texture developed during recrystallization and grain growth, especially when the deformation process follows a complicated deformation path such as in asymmetric rolling. The deformation model is based on a crystal plasticity approach implemented at the length scale of the microstructure that includes deformation mechanisms based on dislocation slip and twinning. The recrystallization simulation is based on a Monte Carlo technique that operates on the output of the deformation simulations. The nucleation criterion during recrystallization is based on the local stored energy and the Monte Carlo technique is used to simulate the growth of the nuclei due to local stored energy differences and curvature. The model predictions are compared with experimental data obtained through electron backscatter analysis and neutron diffraction.

Radhakrishnan, Balasubramaniam [ORNL; Gorti, Sarma B [ORNL; Stoica, Grigoreta M [ORNL; Muralidharan, Govindarajan [ORNL; Stoica, Alexandru Dan [ORNL; Wang, Xun-Li [ORNL; Specht, Eliot D [ORNL; Kenik, Edward A [ORNL; Muth, Thomas R [ORNL

2012-01-01T23:59:59.000Z

99

Development and Evaluation of a Coupled Photosynthesis-Based Gas Exchange Evapotranspiration Model (GEM) for Mesoscale Weather Forecasting Applications  

E-Print Network (OSTI)

Development and Evaluation of a Coupled Photosynthesis-Based Gas Exchange Evapotranspiration Model with a photosynthesis-based scheme and still achieve dynamically consistent results. To demonstrate this transformative potential, the authors developed and coupled a photosynthesis, gas exchange­based surface evapotranspiration

Niyogi, Dev

100

A Model of the Cosmic Ray Induced Atmospheric Neutron Environment  

E-Print Network (OSTI)

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

Kole, Merlin; Salinas, Maria Muñoz

2014-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "atmospheric mesoscale model" 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

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

102

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

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

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

103

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

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

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

104

Mesoscale predictability of an extreme warm-season precipitation event  

E-Print Network (OSTI)

. The Penn State University/NCAR Mesoscale Model version 5 (MM5) was used to conduct predictability experiments, which follow closely to the research conducted by Zhang et al. A control simulation initialized at 00Z 1 July is established over a 30-km grid...

Odins, Andrew Michael

2005-02-17T23:59:59.000Z

105

MULTISPECTRAL SYNTHETIC SCENE GENERATION USING ATMOSPHERIC PROPAGATION AND THERMODYNAMIC MODELS  

E-Print Network (OSTI)

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

Salvaggio, Carl

106

Model projections of atmospheric steering of Sandy-like superstorms  

Science Journals Connector (OSTI)

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

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

2013-01-01T23:59:59.000Z

107

Meso-scale machining capabilities and issues  

SciTech Connect

Meso-scale manufacturing processes are bridging the gap between silicon-based MEMS processes and conventional miniature machining. These processes can fabricate two and three-dimensional parts having micron size features in traditional materials such as stainless steels, rare earth magnets, ceramics, and glass. Meso-scale processes that are currently available include, focused ion beam sputtering, micro-milling, micro-turning, excimer laser ablation, femto-second laser ablation, and micro electro discharge machining. These meso-scale processes employ subtractive machining technologies (i.e., material removal), unlike LIGA, which is an additive meso-scale process. Meso-scale processes have different material capabilities and machining performance specifications. Machining performance specifications of interest include minimum feature size, feature tolerance, feature location accuracy, surface finish, and material removal rate. Sandia National Laboratories is developing meso-scale electro-mechanical components, which require meso-scale parts that move relative to one another. The meso-scale parts fabricated by subtractive meso-scale manufacturing processes have unique tribology issues because of the variety of materials and the surface conditions produced by the different meso-scale manufacturing processes.

BENAVIDES,GILBERT L.; ADAMS,DAVID P.; YANG,PIN

2000-05-15T23:59:59.000Z

108

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

Science Journals Connector (OSTI)

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

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

2008-04-01T23:59:59.000Z

109

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

SciTech Connect

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

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

1996-12-01T23:59:59.000Z

110

The global change research center atmospheric chemistry model  

SciTech Connect

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

Moraes, F.P. Jr.

1995-01-01T23:59:59.000Z

111

Mesoscale symmetries explain dynamical equivalence of food webs  

Science Journals Connector (OSTI)

A goal of complex system research is to identify the dynamical implications of network structure. While early results focused mainly on local or global structural properties, there is now growing interest in mesoscale structures that comprise more than one node but not the whole network. A central challenge is to discover under what conditions the occurrence of a specific mesoscale motif already allows conclusions on the dynamics of a network as a whole. In this paper, we investigate the dynamics of ecological food webs, complex heterogeneous networks of interacting populations. Generalizing the results of MacArthur and Sánchez-García (2009 Phys. Rev. E 80 26117), we show that certain mesoscale symmetries imply the existence of localized dynamical modes. If these modes are unstable the occurrence of the corresponding mesoscale motif implies dynamical instability regardless of the structure of the embedding network. In contrast, if the mode is stable it means that the symmetry can be exploited to reduce the number of nodes in the model, without changing the dynamics of the system. This result explains a previously observed dynamical equivalence between food webs containing a different number of species.

Helge Aufderheide; Lars Rudolf; Thilo Gross

2012-01-01T23:59:59.000Z

112

Posters Mesoscale Simulations of Convective Systems with Data...  

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

7 Posters Mesoscale Simulations of Convective Systems with Data Assimilation During June 1993 in the Southern Great Plains J. Dudhia Mesoscale and Microscale Meteorology Division...

113

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

E-Print Network (OSTI)

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

114

Model of Intraseasonal Oscillations in Earth’s Atmosphere  

Science Journals Connector (OSTI)

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

Elena Kartashova and Victor S. L’vov

2007-05-10T23:59:59.000Z

115

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

Science Journals Connector (OSTI)

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

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

1991-08-01T23:59:59.000Z

116

Thermal shallow water models of geostrophic turbulence in Jovian atmospheres  

SciTech Connect

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

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

2014-01-15T23:59:59.000Z

117

TY JOUR T1 Mesoscale Climatic Simulation of Surface Air Temperature Cooling  

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

Mesoscale Climatic Simulation of Surface Air Temperature Cooling Mesoscale Climatic Simulation of Surface Air Temperature Cooling by Highly Reflective Greenhouses in SE Spain JF Environmental Science Technology A1 Campra Pablo A1 Dev Millstein KW buildings KW Heat Island Group AB p span A long term local cooling trend in surface air temperature has been monitored at the largest concentration of reflective greenhouses in the world at the Province of Almeria SE Spain associated with a dramatic increase in surface albedo in the area The availability of reliable long term climatic field data at this site offers a unique opportunity to test the skill of mesoscale meteorological models describing and predicting the impacts of land use change on local climate Using the Weather Research and Forecast WRF mesoscale model we have run a

118

Subcycled dynamics in the Spectral Community Atmosphere Model, version 4  

SciTech Connect

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

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

2010-01-01T23:59:59.000Z

119

Regional forecasting with global atmospheric models; Final report  

SciTech Connect

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

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

1994-05-01T23:59:59.000Z

120

Global Thermodynamic Atmospheric Modeling: Search for NewHeterogeneous Reactions  

SciTech Connect

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

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

1997-07-03T23:59:59.000Z

Note: This page contains sample records for the topic "atmospheric mesoscale model" 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

A Low Mach Number Model for Moist Atmospheric Flows  

E-Print Network (OSTI)

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

Duarte, Max; Bell, John B

2014-01-01T23:59:59.000Z

122

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

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

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

123

Model Wind over the Central and Southern California Coastal Ocean HSIAO-MING HSU  

E-Print Network (OSTI)

Model Wind over the Central and Southern California Coastal Ocean HSIAO-MING HSU National Center of high-resolution wind in coastal ocean modeling. This paper tests the Coupled Ocean­Atmosphere Mesoscale Prediction System (COAMPS) at the 9-, 27-, and 81-km grid resolutions in simulating wind off the central

124

Posters Surface Flux Intercomparison Between the MM5 Model  

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

Posters Surface Flux Intercomparison Between the MM5 Model and Observations During the Storm-Scale Observations Regional Measurement Program-Fronts Experiment Systems Test 1992 J. Dudhia and S. P. Oncley Mesoscale and Microscale Meteorology Division Atmospheric Technology Division National Center for Atmospheric Research Boulder, Colorado Introduction Mesoscale model 5 (MM5) is being used as a data assimilation tool for the Atmospheric Radiation Measurement (ARM) Program. There is a need to verify that the model physics is consistent with observations under a range of conditions. Surface fluxes of heat, moisture, and momentum are a particular area of uncertainty in the model owing to their dependence on surface properties, some of which are time-dependent. The National Center for Atmospheric Research (NCAR)

125

Model Wind over the Central and Southern California Coastal Ocean  

Science Journals Connector (OSTI)

Recent studies have shown the importance of high-resolution wind in coastal ocean modeling. This paper tests the Coupled Ocean–Atmosphere Mesoscale Prediction System (COAMPS) at the 9-, 27-, and 81-km grid resolutions in simulating wind off the ...

Hsiao-ming Hsu; Lie-Yauw Oey; Walter Johnson; Clive Dorman; Richard Hodur

2007-05-01T23:59:59.000Z

126

Cloud in the operational DWD mesoscale model An extensive documentation of the physics included in the Lokal Modell (LM) can be found  

E-Print Network (OSTI)

in the Lokal Modell (LM) can be found in Doms et al. (2004). Here a short summary of the cloud physics is given-scale clouds Since 26th of April 2004 the Lokal Modell (LM) uses a two-category ice scheme which explicitly S that are considered in this two-category ice scheme of LM. The individual microphysical processes are: Sc condensation

Reading, University of

127

Detailed Atmosphere Modeling for the Neutron Star 1E1207.4–5209: Evidence of Oxygen/Neon Atmosphere  

Science Journals Connector (OSTI)

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

Kaya Mori; Charles J. Hailey

2006-01-01T23:59:59.000Z

128

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

129

Postulated Mesoscale Quantum of Internal Friction Hysteresis  

E-Print Network (OSTI)

Evidence is provided, from yet another experiment, for the existence of a mesoscale quantum of internal friction hysteresis, having the value of the electron rest energy divided by the fine structure constant.

Randall D. Peters

2004-05-27T23:59:59.000Z

130

Oceanic mass transport by mesoscale eddies  

Science Journals Connector (OSTI)

...time-mean ocean circulation transports fluid as a conveyor belt, but fluid parcels can also be trapped and transported discretely...continuously, mesoscale eddies can trap fluid parcels within the eddy core and transport them discretely...

Zhengguang Zhang; Wei Wang; Bo Qiu

2014-07-18T23:59:59.000Z

131

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

E-Print Network (OSTI)

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

Collett Jr., Jeffrey L.

132

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

133

Evaluation of very long baseline interferometry atmospheric modeling improvements  

SciTech Connect

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

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

1994-01-01T23:59:59.000Z

134

NUMERICAL EXPERIMENTS USING MESONH/FOREFIRE COUPLED ATMOSPHERIC-FIRE MODEL  

E-Print Network (OSTI)

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

Boyer, Edmond

135

High Resolution Atmospheric Modeling for Wind Energy Applications  

SciTech Connect

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

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

2010-03-18T23:59:59.000Z

136

Matthew David Parker Department of Marine, Earth, and Atmospheric Sciences Curriculum Vitae  

E-Print Network (OSTI)

EDUCATION ________________________________________________________________________ Colorado State University, Fort Collins, Colorado 2002 Ph.D., Atmospheric science (Mesoscale meteorology) 1999 M.S., Atmospheric. Parker, and J. J. Charney, in press: Regimes of dry convection above wildfires: Sensitivity to fireline

Parker, Matthew D. Brown

137

Spatio-temporal statistical models with applications to atmospheric processes  

SciTech Connect

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

Wikle, C.K.

1996-12-31T23:59:59.000Z

138

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

139

Climate Simulations for 1951–2050 with a Coupled Atmosphere–Ocean Model  

Science Journals Connector (OSTI)

The authors simulate climate change for 1951–2050 using the GISS SI2000 atmospheric model coupled to HYCOM, a quasi-isopycnal ocean model (“ocean E”), and contrast the results with those obtained using the same atmosphere coupled to a passive Q-...

Shan Sun; James E. Hansen

2003-09-01T23:59:59.000Z

140

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 Ã?agedÃ? emissions of primary pollutants or actual production

Note: This page contains sample records for the topic "atmospheric mesoscale model" 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

Coastal Wave Generation and Wave Breaking over Terrain: Two Problems in Mesoscale Wave Dynamics  

E-Print Network (OSTI)

with open circles). The resolved-scale eddy term is shown by stars (no line), with the background viscous part then being the di erence between the net resolved-scale and resolved-scale eddy parts. : : : : : : : : : : : 36 16 Schematic sea breeze system... breeze and mesoscale convective systems. Gravity wave momentum transport away from topography in particular plays an important role in the momentum budget of the atmosphere and hence the general circulation. The present study addresses two aspects...

Qian, Tingting

2010-07-14T23:59:59.000Z

142

A MODEL ATMOSPHERE ANALYSIS OF ALPHA AURIGAE A  

SciTech Connect

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

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

2011-11-20T23:59:59.000Z

143

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

Science Journals Connector (OSTI)

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

R. Avissar; R. A. Pielke

1989-10-01T23:59:59.000Z

144

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

Science Journals Connector (OSTI)

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

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

1997-02-01T23:59:59.000Z

145

Temporal Changes in Wind as Objects for Evaluating Mesoscale Numerical Weather Prediction  

E-Print Network (OSTI)

a method of evaluating numerical weather prediction models by comparing the characteristics of temporal for biases in features forecast by the model. 1. Introduction Verification of numerical weather predictionTemporal Changes in Wind as Objects for Evaluating Mesoscale Numerical Weather Prediction DARAN L

Knievel, Jason Clark

146

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

147

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

SciTech Connect

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

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

2009-09-01T23:59:59.000Z

148

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

Science Journals Connector (OSTI)

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

Fuzhong Weng; Quanhua Liu

2003-11-01T23:59:59.000Z

149

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.

150

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

E-Print Network (OSTI)

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

151

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

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

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

152

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

SciTech Connect

The goal of the project was to determine midlatitude climate predictability associated with tropical-extratropical interactions on interannual-to-interdecadal time scales. Our strategy was to develop and test a hierarchy of climate models, bringing together large GCM-based climate models with simple fluid-dynamical coupled ocean-ice-atmosphere models, through the use of advanced probabilistic network (PN) models. PN models were used to develop a new diagnostic methodology for analyzing coupled ocean-atmosphere interactions in large climate simulations made with the NCAR Parallel Climate Model (PCM), and to make these tools user-friendly and available to other researchers. We focused on interactions between the tropics and extratropics through atmospheric teleconnections (the Hadley cell, Rossby waves and nonlinear circulation regimes) over both the North Atlantic and North Pacific, and the 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

153

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

Science Journals Connector (OSTI)

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

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

2014-10-01T23:59:59.000Z

154

Graduate Opportunities in Atmospheric Modeling to Understand Greenhouse Gas Emissions  

E-Print Network (OSTI)

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

Lin, John Chun-Han

155

Propagation of Wind Energy into the Deep Ocean through a Fully Turbulent Mesoscale Eddy Field  

Science Journals Connector (OSTI)

The authors analyze the 3D propagation of wind-forced near-inertial motions in a fully turbulent mesoscale eddy field with a primitive equation numerical model. Although the wind stress is uniform, the near-inertial motion field quickly becomes ...

Eric Danioux; Patrice Klein; Pascal Rivière

2008-10-01T23:59:59.000Z

156

The Ocean–Land–Atmosphere Model: Optimization and Evaluation of Simulated Radiative Fluxes and Precipitation  

Science Journals Connector (OSTI)

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

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

2010-05-01T23:59:59.000Z

157

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

158

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

E-Print Network (OSTI)

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

Zhang, Minghua

159

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

E-Print Network (OSTI)

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

Gombos, Daniel (Daniel Lawrence)

2009-01-01T23:59:59.000Z

160

Representing Grass– and Shrub–Snow–Atmosphere Interactions in Climate System Models  

Science Journals Connector (OSTI)

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

Glen E. Liston; Christopher A. Hiemstra

2011-04-01T23:59:59.000Z

Note: This page contains sample records for the topic "atmospheric mesoscale model" 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

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

Science Journals Connector (OSTI)

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

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

2001-03-01T23:59:59.000Z

162

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

163

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

164

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

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

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

165

Understanding El Niño in Ocean–Atmosphere General Circulation Models: Progress and Challenges  

Science Journals Connector (OSTI)

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

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

2009-03-01T23:59:59.000Z

166

A coupled mesoscale–microscale framework for wind resource estimation and farm aerodynamics  

Science Journals Connector (OSTI)

Abstract This study discusses the development of a coupled mesoscale–microscale framework for wind resource estimation and farm aerodynamics. WINDWYO is a computational framework for performing coupled mesoscale–microscale simulations. The framework is modular, automated and supports coupling of different mesoscale and microscale solvers using overset or matched grids. The modular nature of the framework and the support for overset grids allows the independent development of mesoscale and microscale solvers and the efficient coupling between the codes. The performance of the framework is evaluated by coupling Weather Research and Forecasting (WRF) model with three microscale computational fluid dynamics (CFD) codes of varying complexity. The solvers used are: (i) UWake: a blade element model with free-vortex wake, (ii) Flowyo: large eddy simulation code with actuator line/disk parametrization of the wind turbine and (iii) HELIOS: detached eddy simulation code with full rotor modeling and adaptive mesh refinement. Power predictions and wake visualization of single turbine and off-shore Lillgrund wind farm in uniform and turbulent inflow are used to demonstrate the capabilities of the framework.

Harish Gopalan; Christopher Gundling; Kevin Brown; Beatrice Roget; Jayanarayanan Sitaraman; Jefferey D. Mirocha; Wayne O. Miller

2014-01-01T23:59:59.000Z

167

AMPS, a real-time mesoscale modeling system, has provided a decade of service for scientific and logistical needs and has helped advance polar numerical weather prediction  

E-Print Network (OSTI)

and logistical needs and has helped advance polar numerical weather prediction as well as understanding support for the USAP. The concern at the time was the numerical weather prediction (NWP) guidance-time implementation of the Weather Research and Forecasting model (WRF; Skamarock et al. 2008) to support the U

Howat, Ian M.

168

The sensitivity of the PSU-NCAR model (MM5) to cumulus parameterization in simulating the mesoscale environment associated with 2 June 1995 West Texas tornado outbreak  

E-Print Network (OSTI)

schemes. The model simulation has a 67 x 67 grid domain centered at 35[] N and 102[] W with 27 km grid spacing, and starts at 12 UTC 2 June for 12-h forecast. The simulation results showed that, even though the general features agreed well among the three...

Han, Sang-Ok

2012-06-07T23:59:59.000Z

169

Mesoscale coupled ocean-atmosphere feedbacks in boundary current systems  

E-Print Network (OSTI)

response of the ocean eddies . The power spectrum of thethe ocean. As such, the larger energy in the power spectrumocean eddies. On the other hand, Smoothed ROMS has higher power

Putrasahan, Dian Ariyani

2012-01-01T23:59:59.000Z

170

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

171

Separation of climatological imprints of the Kuroshio Extension and Oyashio fronts on the wintertime atmospheric boundary layer: Their sensitivity to SST resolution prescribed for atmospheric reanalysis  

Science Journals Connector (OSTI)

Mesoscale structures of the wintertime marine atmospheric boundary layer (MABL) as climatological imprints of oceanic fronts within the Kuroshio-Oyashio Extension (KOE) region east of Japan are investigated, by taking advantage of high horizontal ...

Ryusuke Masunaga; Hisashi Nakamura; Takafumi Miyasaka; Kazuaki Nishii; Youichi Tanimoto

172

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

SciTech Connect

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

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

1982-04-01T23:59:59.000Z

173

Numerical Simulation of Micro?atmospheric Environment by LES in a District of Beijing  

Science Journals Connector (OSTI)

This paper investigates wind field and traffic pollutant dispersion at street level in a local urban area. A coupling method is employed between the mesoscale model weather research and forecast (WRF) for the atmospheric flow of whole city and the large eddy simulation (LES) method for local environmental flows. A combined model is proposed for building clusters in the urban area. The wind speed temperature and carbon monoxide concentration fields are computed from 9 am of October 26 2009 to 8 am of the next day in a district of Beijing and the results show a good agreement with the observation.

Y. S. Liu; S. G. Miao; C. L. Zhang; G. X. Cui; Z. S. Zhang

2011-01-01T23:59:59.000Z

174

Simulating atmosphere flow for wind energy applications with WRF-LES  

SciTech Connect

Forecasts of available wind energy resources at high spatial resolution enable users to site wind turbines in optimal locations, to forecast available resources for integration into power grids, to schedule maintenance on wind energy facilities, and to define design criteria for next-generation turbines. This array of research needs implies that an appropriate forecasting tool must be able to account for mesoscale processes like frontal passages, surface-atmosphere interactions inducing local-scale circulations, and the microscale effects of atmospheric stability such as breaking Kelvin-Helmholtz billows. This range of scales and processes demands a mesoscale model with large-eddy simulation (LES) capabilities which can also account for varying atmospheric stability. Numerical weather prediction models, such as the Weather and Research Forecasting model (WRF), excel at predicting synoptic and mesoscale phenomena. With grid spacings of less than 1 km (as is often required for wind energy applications), however, the limits of WRF's subfilter scale (SFS) turbulence parameterizations are exposed, and fundamental problems arise, associated with modeling the scales of motion between those which LES can represent and those for which large-scale PBL parameterizations apply. To address these issues, we have implemented significant modifications to the ARW core of the Weather Research and Forecasting model, including the Nonlinear Backscatter model with Anisotropy (NBA) SFS model following Kosovic (1997) and an explicit filtering and reconstruction technique to compute the Resolvable Subfilter-Scale (RSFS) stresses (following Chow et al, 2005).We are also modifying WRF's terrain-following coordinate system by implementing an immersed boundary method (IBM) approach to account for the effects of complex terrain. Companion papers presenting idealized simulations with NBA-RSFS-WRF (Mirocha et al.) and IBM-WRF (K. A. Lundquist et al.) are also presented. Observations of flow through the Altamont Pass (Northern California) wind farm are available for validation of the WRF modeling tool for wind energy applications. In this presentation, we use these data to evaluate simulations using the NBA-RSFS-WRF tool in multiple configurations. We vary nesting capabilities, multiple levels of RSFS reconstruction, SFS turbulence models (the new NBA turbulence model versus existing WRF SFS turbulence models) to illustrate the capabilities of the modeling tool and to prioritize recommendations for operational uses. Nested simulations which capture both significant mesoscale processes as well as local-scale stable boundary layer effects are required to effectively predict available wind resources at turbine height.

Lundquist, J K; Mirocha, J D; Chow, F K; Kosovic, B; Lundquist, K A

2008-01-14T23:59:59.000Z

175

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

SciTech Connect

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

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

2008-12-31T23:59:59.000Z

176

Modeling of the optical properties of nonspherical particles in the atmosphere  

E-Print Network (OSTI)

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

Chen, Guang

2009-05-15T23:59:59.000Z

177

Lagrangian study of transport and mixing in a mesoscale eddy street  

E-Print Network (OSTI)

We use dynamical systems approach and Lagrangian tools to study surface transport and mixing of water masses in a selected coastal region of the Japan Sea with moving mesoscale eddies associated with the Primorskoye Current. Lagrangian trajectories are computed for a large number of particles in an interpolated velocity field generated by a numerical regional multi-layer eddy-resolving circulation model. We compute finite-time Lyapunov exponents for a comparatively long period of time by the method developed and plot the Lyapunov synoptic map quantifying surface transport and mixing in that region. This map uncovers the striking flow structures along the coast with a mesoscale eddy street and repelling material lines. We propose new Lagrangian diagnostic tools --- the time of exit of particles off a selected box, the number of changes of the sign of zonal and meridional velocities --- to study transport and mixing by a pair of strongly interacting eddies often visible at sea-surface temperature satellite images in that region. We develop a technique to track evolution of clusters of particles, streaklines and material lines. The Lagrangian tools used allow us to reveal mesoscale eddies and their structure, to track different phases of the coastal flow, to find inhomogeneous character of transport and mixing on mesoscales and submesoscales and to quantify mixing by the values of exit times and the number of times particles wind around the eddy's center.

S. V. Prants; M. V. Budyansky; V. I. Ponomarev; M. Yu. Uleysky

2012-02-02T23:59:59.000Z

178

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

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

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

179

Formation of mesoscale roughening in 6022-T4 Al sheets deformed in plane-strain tension  

Science Journals Connector (OSTI)

Mesoscale surface-roughening evolution in 6022-T4 Al sheets was ... are central to the formation of mesoscale surface roughening.

Y. S. Choi; H. R. Piehler; A. D. Rollett

2004-02-01T23:59:59.000Z

180

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

E-Print Network (OSTI)

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

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

2007-08-12T23:59:59.000Z

Note: This page contains sample records for the topic "atmospheric mesoscale model" 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

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

E-Print Network (OSTI)

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

Dabdub, Donald

182

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

183

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

184

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

185

Atmospheric models hybrid OpenMP/MPI implementation multicore cluster evaluation  

Science Journals Connector (OSTI)

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

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

2012-01-01T23:59:59.000Z

186

Coupled AtmosphereWildland Fire Modelling Jean Baptiste Filippi1  

E-Print Network (OSTI)

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

Clements, Craig

187

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

Science Journals Connector (OSTI)

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

J. M. Murphy

1995-03-01T23:59:59.000Z

188

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

SciTech Connect

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

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

1986-01-01T23:59:59.000Z

189

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

190

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

191

MODELING ATMOSPHERIC RELEASES OF TRITIUM FROM NUCLEAR INSTALLATIONS  

SciTech Connect

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

Okula, K

2007-01-17T23:59:59.000Z

192

A Flexible Atmospheric Modeling Framework for the CESM  

SciTech Connect

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

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

2014-11-12T23:59:59.000Z

193

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

Science Journals Connector (OSTI)

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

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

194

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

195

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

Science Journals Connector (OSTI)

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

2009-01-01T23:59:59.000Z

196

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

E-Print Network (OSTI)

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

Jackman, Charles H.

197

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

198

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

E-Print Network (OSTI)

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

Aneja, Viney P.

199

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

E-Print Network (OSTI)

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

Johnson, Robert E.

200

Model atmospheres for novae during the early stages  

SciTech Connect

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

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

1989-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "atmospheric mesoscale model" 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

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

E-Print Network (OSTI)

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

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

2004-05-20T23:59:59.000Z

202

Sensitivity of Mesoscale Gravity Waves to the Baroclinicity of Jet-Front Systems SHUGUANG WANG AND FUQING ZHANG  

E-Print Network (OSTI)

life cycles of baroclinic waves with a high-resolution mesoscale model. Four simulations are made starting from two-dimensional baroclinic jets having different static stability and wind shear in order-dimensional spectral analysis demonstrates that these gravity waves have multiple components with different wave

203

Ensemble Kalman Filter Analyses and Forecasts of a Severe Mesoscale Convective System Using Different Choices of Microphysics Schemes  

Science Journals Connector (OSTI)

A Weather Research and Forecasting Model (WRF)-based ensemble data assimilation system is used to produce storm-scale analyses and forecasts of the 4–5 July 2003 severe mesoscale convective system (MCS) over Indiana and Ohio, which produced ...

Dustan M. Wheatley; Nusrat Yussouf; David J. Stensrud

2014-09-01T23:59:59.000Z

204

A Model-Based Decomposition of the Sea Ice–Atmosphere Feedback over the Barents Sea during Winter  

Science Journals Connector (OSTI)

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

Jessica Liptak; Courtenay Strong

2014-04-01T23:59:59.000Z

205

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

E-Print Network (OSTI)

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

Wegner, T.

206

Lagrangian study of transport and mixing in a mesoscale eddy street  

E-Print Network (OSTI)

We use dynamical systems approach and Lagrangian tools to study surface transport and mixing of water masses in a selected coastal region of the Japan Sea with moving mesoscale eddies associated with the Primorskoye Current. Lagrangian trajectories are computed for a large number of particles in an interpolated velocity field generated by a numerical regional multi-layer eddy-resolving circulation model. We compute finite-time Lyapunov exponents for a comparatively long period of time by the method developed and plot the Lyapunov synoptic map quantifying surface transport and mixing in that region. This map uncovers the striking flow structures along the coast with a mesoscale eddy street and repelling material lines. We propose new Lagrangian diagnostic tools --- the time of exit of particles off a selected box, the number of changes of the sign of zonal and meridional velocities --- to study transport and mixing by a pair of strongly interacting eddies often visible at sea-surface temperature satellite imag...

Prants, S V; Ponomarev, V I; Uleysky, M Yu; 10.1016/j.ocemod.2011.02.008

2012-01-01T23:59:59.000Z

207

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

E-Print Network (OSTI)

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

Kempton, Eliza M -R; Heng, Kevin

2014-01-01T23:59:59.000Z

208

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

209

Mesoscale Quantization and Self-Organized Stability  

E-Print Network (OSTI)

In the world of technology, one of the most important forms of friction is that of rolling friction. Yet it is one of the least studied of all the known forms of energy dissipation. In the present experiments we investigate the oscillatory free-decay of a rigid cube, whose side-length is less than the diameter of the rigid cylinder on which it rests. The resulting free-decay is one of harmonic motion with damping. The non-dissipative character of the oscillation yields to a linear differential equation; however, the damping is found to involve more than a deterministic nonlinearity. Dominated by rolling friction, the damping is sensitive to the material properties of the contact surfaces. For `clean' surfaces of glass on glass, the decay shows features of mesoscale quantization and self-organized stability.

Randall D. Peters

2005-06-16T23:59:59.000Z

210

Modeling of atmospheric-pressure plasma columns sustained by surface waves  

Science Journals Connector (OSTI)

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

Y. Kabouzi; D. B. Graves; E. Castaños-Martínez; M. Moisan

2007-01-09T23:59:59.000Z

211

Satellite Observations of Mesoscale Eddy-Induced Ekman Pumping  

Science Journals Connector (OSTI)

Three mechanisms for self-induced Ekman pumping in the interiors of mesoscale ocean eddies are investigated. The first arises from the surface stress that occurs because of differences between surface wind and ocean velocities, resulting in Ekman ...

Peter Gaube; Dudley B. Chelton; Roger M. Samelson; Michael G. Schlax; Larry W. O’Neill

212

Advances in mesoscale thermal management technologies for microelectronics  

Science Journals Connector (OSTI)

This paper presents recent advances in a number of novel, high-performance cooling techniques for emerging electronics applications. Critical enabling thermal management technologies covered include microchannel transport and micropumps, jet impingement, ... Keywords: Mesoscale, Microelctronics, Thermal management

Suresh V. Garimella

2006-11-01T23:59:59.000Z

213

Life Cycle and Mesoscale Frontal Structure of an Intermountain Cyclone  

Science Journals Connector (OSTI)

High-resolution analyses and MesoWest surface observations are used to examine the life cycle and mesoscale frontal structure of the “Tax Day Storm,” an intermountain cyclone that produced the second lowest sea level pressure observed in Utah ...

Gregory L. West; W. James Steenburgh

2010-07-01T23:59:59.000Z

214

Structures and Dynamics of Quasi-2D Mesoscale Convective Systems  

Science Journals Connector (OSTI)

Recently, three distinct archetypes for midlatitude linear mesoscale convective systems (MCSs) have been identified. This article focuses on the fundamentals of two of these archetypes: convective lines with trailing stratiform (TS) precipitation ...

Matthew D. Parker; Richard H. Johnson

2004-03-01T23:59:59.000Z

215

Toward a Mesoscale Observation Network in Southeast Asia  

Science Journals Connector (OSTI)

The current weather observation network in Southeast Asia is unable to support the accurate monitoring and prediction of the region's predominantly convective weather. Establishing a multisensor mesoscale observation network comprising automated ...

Tieh-Yong Koh; Chee-Kiat Teo

2009-04-01T23:59:59.000Z

216

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

SciTech Connect

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

Bloom, S.G.

1993-10-06T23:59:59.000Z

217

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

218

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

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

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

219

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

E-Print Network (OSTI)

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

S. A. Khan; D. V. Shulyak

2006-07-20T23:59:59.000Z

220

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

Science Journals Connector (OSTI)

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

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

2014-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "atmospheric mesoscale model" 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

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

SciTech Connect

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

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

2010-09-15T23:59:59.000Z

222

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

223

Technical Sessions Parameterization of Convective Clouds, Mesoscale...  

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

and Convective-Generated Clouds W. R. Cotton Department of Atmospheric Science Colorado State University Fort Collins, CO 80523 This presentation is a summary of research...

224

NOAA federal/state cooperative program in atmospheric modification research. Collected publication titles and abstracts. Technical memo  

SciTech Connect

The volume contains the titles and abstracts of technical publications through fiscal year 1992 that are the products of the NOAA Federal/State Cooperative Program in Atmospheric Modification Research. The program is focused on the very interdisciplinary science of purposeful cloud modification for precipitation enhancement and hail suppression, and unintentional modification of clouds and precipitation. The audience includes, for example, water managers, policy makers, scientists, practitioners in the field, and the interested public. Listed are publications on topics including but not limited to: cloud and precipitation processes, numerical cloud and atmospheric mesoscale modeling, atmospheric and storm monitoring instrumentation and technologies, aerosol transport and dispersion in clouds and over complex terrain, cloud seeding technologies and effects, agricultural responses to cloud modification, weather economics and societal aspects of cloud modification, unintentional weather and climate modification, and precipitation and hydrological assessment and forecasting.

Reinking, R.F.

1993-04-01T23:59:59.000Z

225

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

226

Towards quantifying mesoscale flows in the troposphere using Raman lidar and sondes  

SciTech Connect

Water vapor plays an important role in the energetics of the boundary layer processes which in turn play a key role in regulating regional and global climate. It plays a primary role in Earth`s hydrological cycle, in radiation balance as a direct absorber of infrared radiation, and in atmospheric circulation as a latent heat energy source as well as in determining cloud development and atmospheric stability. Water vapor concentration, expressed as a mass mixing ratio, is conserved in all meteorological processes except condensation and evaporation. This property makes it an ideal choice for studying many of the atmosphere`s dynamic features. Raman scattering measurements from lidar also allow retrieval of water vapor mixing ratio profiles at high temporal and vertical resolution. Raman lidars sense water vapor to altitudes not achievable with towers and surface systems, sample the atmosphere at much higher temporal resolution than radiosondes or satellites, and do not require strong vertical gradients or turbulent fluctuations in temperature that is required by acoustic sounders and radars. Analysis of highly resolved water vapor profiles are used here to characterize two important mesoscale flows: thunderstorm outflows and a cold front passage.

Demoz, B.; Evans, K. [Univ. of Maryland Baltimore County, Baltimore, MD (United States); Starr, D. [NASA, Greenbelt, MD (United States). Goddard Space Flight Center] [and others

1998-03-01T23:59:59.000Z

227

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

228

GEOCARBSULF: A combined model for Phanerozoic atmospheric O2 and CO2  

Science Journals Connector (OSTI)

A model for the combined long-term cycles of carbon and sulfur has been constructed which combines all the factors modifying weathering and degassing of the GEOCARB III model [Berner R.A., Kothavala Z., 2001. GEOCARB III: a revised model of atmospheric CO2 over Phanerozoic time. Am. J. Sci. 301, 182–204] for CO2 with rapid recycling and oxygen dependent carbon and sulfur isotope fractionation of an isotope mass balance model for O2 [Berner R.A., 2001. Modeling atmospheric O2 over Phanerozoic time. Geochim. Cosmochim. Acta 65, 685–694]. New isotopic data for both carbon and sulfur are used and new feedbacks are created by combining the models. Sensitivity analysis is done by determining (1) the effect on weathering rates of using rapid recycling (rapid recycling treats carbon and sulfur weathering in terms of young rapidly weathering rocks and older more slowly weathering rocks); (2) the effect on O2 of using different initial starting conditions; (3) the effect on O2 of using different data for carbon isotope fractionation during photosynthesis and alternative values of oceanic ?13C for the past 200 million years; (4) the effect on sulfur isotope fractionation and on O2 of varying the size of O2 feedback during sedimentary pyrite formation; (5) the effect on O2 of varying the dependence of organic matter and pyrite weathering on tectonic uplift plus erosion, and the degree of exposure of coastal lands by sea level change; (6) the effect on CO2 of adding the variability of volcanic rock weathering over time [Berner, R.A., 2006. Inclusion of the weathering of volcanic rocks in the GEOCARBSULF model. Am. J. Sci. 306 (in press)]. Results show a similar trend of atmospheric CO2 over the Phanerozoic to the results of GEOCARB III, but with some differences during the early Paleozoic and, for variable volcanic rock weathering, lower CO2 values during the Mesozoic. Atmospheric oxygen shows a major broad late Paleozoic peak with a maximum value of about 30% O2 in the Permian, a secondary less-broad peak centered near the Silurian/Devonian boundary, variation between 15% and 20% O2 during the Cambrian and Ordovician, a very sharp drop from 30% to 15% O2 at the Permo-Triassic boundary, and a more-or less continuous rise in O2 from the late Triassic to the present.

Robert A. Berner

2006-01-01T23:59:59.000Z

229

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

Science Journals Connector (OSTI)

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

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

2012-07-01T23:59:59.000Z

230

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

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

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

231

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

E-Print Network (OSTI)

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

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

2008-03-06T23:59:59.000Z

232

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

SciTech Connect

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

Prusa, Joseph

2012-05-08T23:59:59.000Z

233

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

SciTech Connect

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

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

2013-02-07T23:59:59.000Z

234

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

E-Print Network (OSTI)

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

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

2014-01-01T23:59:59.000Z

235

Mesoscale Origin of the Enhanced Cycling-Stability of the Si...  

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

Mesoscale Origin of the Enhanced Cycling-Stability of the Si-Conductive Polymer Anode for Li-ion Batteries. Mesoscale Origin of the Enhanced Cycling-Stability of the Si-Conductive...

236

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

237

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

Science Journals Connector (OSTI)

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

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

2013-01-01T23:59:59.000Z

238

Oxy-nitroso shielding burst model of cold atmospheric plasma therapeutics  

Science Journals Connector (OSTI)

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

David B Graves

2014-01-01T23:59:59.000Z

239

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

SciTech Connect

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

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

2009-05-02T23:59:59.000Z

240

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

Science Journals Connector (OSTI)

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

Yukinori Sakiyama; David B. Graves

2009-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "atmospheric mesoscale model" 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

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

SciTech Connect

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

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

2012-05-08T23:59:59.000Z

242

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

SciTech Connect

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

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

2006-05-01T23:59:59.000Z

243

Silicon Micromachined Dimensional Calibration Artifact for Mesoscale Measurement Machines  

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

Silicon Micromachined Dimensional Calibration Silicon Micromachined Dimensional Calibration Artifact for Mesoscale Measurement Machines 1 Silicon Micromachined Dimensional Calibration Artifact for Mesoscale Measurement Machines 2 Sandia National Laboratories PO Box 5800 Albuquerque, NM 87185 USA Hy D. Tran, PhD, PE Phone: (505)844-5417 Fax: (505)844-4372 hdtran@sandia.gov AFFIRMATION: I affirm that all information submitted as a part of, or supplemental to, this entry is a fair and accurate representation of this product. ___________________________________ Hy D. Tran Not a joint entry. Silicon Micromachined Dimensional Calibration Artifact for Mesoscale Measurement Machines The silicon hybrid artifact is an anisotropic-etched silicon standard that is used as a calibration reference artifact to calibrate vision-based and

244

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

SciTech Connect

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

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

2004-07-01T23:59:59.000Z

245

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

SciTech Connect

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

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

2013-08-10T23:59:59.000Z

246

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

Science Journals Connector (OSTI)

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

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

2006-04-01T23:59:59.000Z

247

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

SciTech Connect

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

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

2011-10-27T23:59:59.000Z

248

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

SciTech Connect

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

Howard Barker; Jason Cole

2012-05-17T23:59:59.000Z

249

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

SciTech Connect

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

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

2013-12-01T23:59:59.000Z

250

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

251

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

SciTech Connect

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

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

1991-01-01T23:59:59.000Z

252

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

SciTech Connect

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

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

1991-01-01T23:59:59.000Z

253

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

E-Print Network (OSTI)

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

Dvornikov, Maxim

2014-01-01T23:59:59.000Z

254

An experimental and numerical investigation of premixed syngas combustion dynamics in mesoscale channels with controlled wall temperature profiles  

Science Journals Connector (OSTI)

Abstract The dynamics in H2/CO/O2/N2 premixed combustion was investigated experimentally and numerically in a 7-mm height mesoscale channel at atmospheric pressure, fuel–lean equivalence ratios 0.25–0.42, volumetric CO:H2 ratios 1:1 to 20:1, and wall temperatures 550–1320 K. Experiments were performed in an optically-accessible channel-flow reactor and involved high-speed (up to 1 kHz) planar laser induced fluorescence (LIF) of the OH radical and thermocouple measurements of the upper and lower channel wall temperatures. Simulations were carried out with a transient 2-D code, which included an elementary syngas reaction mechanism and detailed species transport. Demarcation of the experimentally-observed parameter space separating stationary and oscillatory combustion modes indicated that the former were favored at the higher wall temperatures and higher CO:H2 volumetric ratios, while the latter predominately appeared at the lower wall temperatures and lower CO:H2 ratios. The numerical model reproduced very well all stationary combustion modes, which included V-shaped and asymmetric (upper or lower) modes, in terms of flame shapes and flame anchoring positions. Simulations of the oscillatory flames, which appeared in the form of ignition/extinction events of varying spatial extents, were very sensitive to the specific boundary conditions and reproduced qualitatively the flame topology, the ignition sequence (including the periodic reversion from upper-asymmetric to lower-asymmetric flame propagation), and the range of measured oscillation frequencies. Predicted emissions in the stationary modes ranged from 25 to 94 ppm-mass for CO and from 0.1 to 0.3 ppm-mass for H2, while in the oscillatory modes incomplete combustion of both CO and H2 was attested during their oscillation period.

Andrea Brambilla; Marco Schultze; Christos E. Frouzakis; John Mantzaras; Rolf Bombach; Konstantinos Boulouchos

2014-01-01T23:59:59.000Z

255

Molecule-Mimetic Chemistry and Mesoscale Self-Assembly  

E-Print Network (OSTI)

Molecule-Mimetic Chemistry and Mesoscale Self-Assembly NED B. BOWDEN, MARCUS WECK, INSUNG S. CHOI systems. We suggest that it will be possible to develop complex structures composed of "objects" that self-assemble, shape recognition, and size exclusion can be used to guide the self-assembly of these objects

Prentiss, Mara

256

Mesoscale Science: Lessons from and Opportunities for Nanoscience  

Science Journals Connector (OSTI)

Earlier this month, I attended and spoke at a workshop of the Chemical Sciences Roundtable on mesoscale science. ... We hope that having ACS Nano to share both challenges and successes across communities will help accelerate advances by cross-fertilizing efforts and by inspiring scientists and engineers around the world. ...

Paul S. Weiss

2014-11-25T23:59:59.000Z

257

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

SciTech Connect

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

Buckley, R.

2001-06-27T23:59:59.000Z

258

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

SciTech Connect

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

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

2010-10-10T23:59:59.000Z

259

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

SciTech Connect

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

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

2009-01-01T23:59:59.000Z

260

Impact of Resolution on Simulation of Closed Mesoscale Cellular Convection Identified by Dynamically Guided Watershed Segmentation  

SciTech Connect

Organized mesoscale cellular convection (MCC) is a common feature of marine stratocumulus that forms in response to a balance between mesoscale dynamics and smaller scale processes such as cloud radiative cooling and microphysics. We use the Weather Research and Forecasting model with chemistry (WRF-Chem) and fully coupled cloud-aerosol interactions to simulate marine low clouds during the VOCALS-REx campaign over the southeast Pacific. A suite of experiments with 3- and 9-km grid spacing indicates resolution-dependent behavior. The simulations with finer grid spacing have smaller liquid water paths and cloud fractions, while cloud tops are higher. The observed diurnal cycle is reasonably well simulated. To isolate organized MCC characteristics we develop a new automated method, which uses a variation of the watershed segmentation technique that combines the detection of cloud boundaries with a test for coincident vertical velocity characteristics. This ensures that the detected cloud fields are dynamically consistent for closed MCC, the most common MCC type over the VOCALS-REx region. We demonstrate that the 3-km simulation is able to reproduce the scaling between horizontal cell size and boundary layer height seen in satellite observations. However, the 9-km simulation is unable to resolve smaller circulations corresponding to shallower boundary layers, instead producing invariant MCC horizontal scale for all simulated boundary layers depths. The results imply that climate models with grid spacing of roughly 3 km or smaller may be needed to properly simulate the MCC structure in the marine stratocumulus regions.

Martini, Matus; Gustafson, William I.; Yang, Qing; Xiao, Heng

2014-11-27T23:59:59.000Z

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261

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

SciTech Connect

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

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

2014-01-01T23:59:59.000Z

262

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

SciTech Connect

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

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

1993-09-01T23:59:59.000Z

263

Simple model to estimate the contribution of atmospheric CO2 to the Earth’s greenhouse effect  

Science Journals Connector (OSTI)

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

Derrek J. Wilson; Julio Gea-Banacloche

2012-01-01T23:59:59.000Z

264

Comparison of Atmospheric Water Vapor in Observational and Model Data Sets  

SciTech Connect

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

Boyle, J.S.

2000-03-01T23:59:59.000Z

265

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

266

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

267

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

SciTech Connect

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

Simpkins, A.A.

2001-04-04T23:59:59.000Z

268

Atmospheric Physics and Earth Observations  

Science Journals Connector (OSTI)

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

M. HERSÉ

1984-07-13T23:59:59.000Z

269

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

Science Journals Connector (OSTI)

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

Kosuke Ito; Tohru Kuroda; Kazuo Saito; Akiyoshi Wada

270

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

E-Print Network (OSTI)

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

Steinhoff, Heinz-Jürgen

271

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

SciTech Connect

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

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

2012-04-09T23:59:59.000Z

272

Atmospheric Chemistry  

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

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

273

Convective cell development and propagation in a mesoscale convective complex  

E-Print Network (OSTI)

~ , National Fisheries University of Pusan Chairman of Advisory Committee: Dr ~ Kennth CD Brundidge A case study was made of the mesoscale convective complex (MCC) which occurred over southern Oklahoma and northern Texas on 27 May 1981. This storm moved... in an east-southeasterly direction and during much of its lifetime was observable by radars at Oklahoma City, OK and Stephenville, TX. It was found that the direction of cell (VIP level 3 or more reflectivity) propagation was somewhat erratic...

Ahn, Yoo-Shin

2012-06-07T23:59:59.000Z

274

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

Science Journals Connector (OSTI)

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

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

2003-10-17T23:59:59.000Z

275

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.

276

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

SciTech Connect

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

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

1997-02-24T23:59:59.000Z

277

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

SciTech Connect

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

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

2013-11-08T23:59:59.000Z

278

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

SciTech Connect

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

Leung, Lai R.; Qian, Yun

2009-02-12T23:59:59.000Z

279

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

SciTech Connect

This project examined the potential large-scale influence of marine aerosol cycling on atmospheric chemistry, physics and radiative transfer. Measurements indicate that the size-dependent generation of marine aerosols by wind waves at the ocean surface and the subsequent production and cycling of halogen-radicals are important but poorly constrained processes that influence climate regionally and globally. A reliable capacity to examine the role of marine aerosol in the global-scale atmospheric system requires that the important size-resolved chemical processes be treated explicitly. But the treatment of multiphase chemistry across the breadth of chemical scenarios encountered throughout the atmosphere is sensitive to the initial conditions and the precision of the solution method. This study examined this sensitivity, constrained it using high-resolution laboratory and field measurements, and deployed it in a coupled chemical-microphysical 3-D atmosphere model. First, laboratory measurements of fresh, unreacted marine aerosol were used to formulate a sea-state based marine aerosol source parameterization that captured the initial organic, inorganic, and physical conditions of the aerosol population. Second, a multiphase chemical mechanism, solved using the Max Planck Institute for 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

280

Center for Mesoscale Transport Properties (m2M) | U.S. DOE Office...  

Office of Science (SC) Website

from molecular to mesoscale (m2m); to minimize heat and maximize work of electrical energy storage devices. Research Topics energy storage (including batteries and...

Note: This page contains sample records for the topic "atmospheric mesoscale model" from the National Library of EnergyBeta (NLEBeta).
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281

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

282

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

Science Journals Connector (OSTI)

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

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

1999-08-01T23:59:59.000Z

283

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

Science Journals Connector (OSTI)

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

Paul C. Loikith; Anthony J. Broccoli

284

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

Science Journals Connector (OSTI)

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

Yuri Akishev; N. Trushkin; M. Grushin…

2012-01-01T23:59:59.000Z

285

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

E-Print Network (OSTI)

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

286

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

E-Print Network (OSTI)

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

Wang, Jun-Chieh

2014-01-01T23:59:59.000Z

287

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

Science Journals Connector (OSTI)

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

Le Ngoc Ly

1986-08-01T23:59:59.000Z

288

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

E-Print Network (OSTI)

Biogeosciences, 6, 2099–2120, 2009 www.biogeosciences.net/6/2099/2009/ © Author(s) 2009. This work is distributed under the Creative Commons Attribution 3.0 License. Biogeosciences Carbon-nitrogen interactions regulate climate-carbon cycle feedbacks.... Inclusion of fundamental ecological interactions between carbon and nitrogen cycles in the land component of an atmosphere-ocean general circulation model (AOGCM) leads to decreased carbon uptake associated with CO2 fertil- ization, and increased carbon...

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

2009-01-01T23:59:59.000Z

289

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

SciTech Connect

Abstract The International Monitoring System (IMS) of the Comprehensive-Nuclear-Test-Ban-Treaty monitors the atmosphere for radioactive xenon leaking from underground nuclear explosions. Emissions from medical isotope production represent a challenging background signal when determining whether measured radioxenon in the atmosphere is associated with a nuclear explosion prohibited by the treaty. The Australian Nuclear Science and Technology Organisation (ANSTO) operates a reactor and medical isotope production facility in Lucas Heights, Australia. This study uses two years of release data from the ANSTO medical isotope production facility and Xe-133 data from three IMS sampling locations to estimate the annual releases of Xe-133 from medical isotope production facilities in Argentina, South Africa, and Indonesia. Atmospheric dilution factors derived from a global atmospheric transport model were used in an optimization scheme to estimate annual release values by facility. The annual releases of about 6.8×1014 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

290

Mesoscale Self-Assembly of Hexagonal Plates Using Lateral Capillary Forces: Synthesis Using the "Capillary Bond"  

E-Print Network (OSTI)

Mesoscale Self-Assembly of Hexagonal Plates Using Lateral Capillary Forces: Synthesis Using examines self-assembly in a quasi-two-dimensional, mesoscale system. The system studied here involves and hydrophilic faces on the hexagonal plates led to three outcomes: (i) the extension of the strategies of self-assembly

Prentiss, Mara

291

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

Science Journals Connector (OSTI)

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

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

1995-01-01T23:59:59.000Z

292

ATMOSPHERIC DENSITY ESTIMATION USING SATELLITE PRECISION ORBIT EPHEMERIDES  

E-Print Network (OSTI)

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

Arudra, Anoop Kumar

2011-04-22T23:59:59.000Z

293

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

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

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

294

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

E-Print Network (OSTI)

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

Chen, Gang

295

Comparing radial velocities of atmospheric lines with radiosonde measurements  

Science Journals Connector (OSTI)

......30km u m1 0.01 E-W wind component, east positive v m1 0.01 N-S wind component, north positive...mesoscale models [MM5 (4), WRF (5), MesoNH (6...model augmented by some local weather stations. Details...KAMM) and compare with wind measurements taken at......

P. Figueira; F. Kerber; A Chacon; C. Lovis; N. C. Santos; G. Lo Curto; M. Sarazin; F. Pepe

2012-03-11T23:59:59.000Z

296

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.

297

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

Science Journals Connector (OSTI)

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

Georgios Matheou; Daniel Chung

2014-12-01T23:59:59.000Z

298

Two-Temperature Two-Dimensional Non Chemical Equilibrium Modeling of Ar–CO2–H2 Induction Thermal Plasmas at Atmospheric Pressure  

Science Journals Connector (OSTI)

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

Sharif Abdullah Al-Mamun; Yasunori Tanaka…

2010-02-01T23:59:59.000Z

299

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

Science Journals Connector (OSTI)

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

J. M. Murphy

1995-01-01T23:59:59.000Z

300

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

Science Journals Connector (OSTI)

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

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

2011-07-01T23:59:59.000Z

Note: This page contains sample records for the topic "atmospheric mesoscale model" 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

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

SciTech Connect

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

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

1997-11-01T23:59:59.000Z

302

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

E-Print Network (OSTI)

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

2014-01-01T23:59:59.000Z

303

An analytical coarse-graining method which preserves the free energy, structural correlations, and thermodynamic state of polymer melts from the atomistic to the mesoscale  

SciTech Connect

Structural and thermodynamic consistency of coarse-graining models across multiple length scales is essential for the predictive role of multi-scale modeling and molecular dynamic simulations that use mesoscale descriptions. Our approach is a coarse-grained model based on integral equation theory, which can represent polymer chains at variable levels of chemical details. The model is analytical and depends on molecular and thermodynamic parameters of the system under study, as well as on the direct correlation function in the k ? 0 limit, c{sub 0}. A numerical solution to the PRISM integral equations is used to determine c{sub 0}, by adjusting the value of the effective hard sphere diameter, d{sub HS}, to agree with the predicted equation of state. This single quantity parameterizes the coarse-grained potential, which is used to perform mesoscale simulations that are directly compared with atomistic-level simulations of the same system. We test our coarse-graining formalism by comparing structural correlations, isothermal compressibility, equation of state, Helmholtz and Gibbs free energies, and potential energy and entropy using both united atom and coarse-grained descriptions. We find quantitative agreement between the analytical formalism for the thermodynamic properties, and the results of Molecular Dynamics simulations, independent of the chosen level of representation. In the mesoscale description, the potential energy of the soft-particle interaction becomes a free energy in the coarse-grained coordinates which preserves the excess free energy from an ideal gas across all levels of description. The structural consistency between the united-atom and mesoscale descriptions means the relative entropy between descriptions has been minimized without any variational optimization parameters. The approach is general and applicable to any polymeric system in different thermodynamic conditions.

McCarty, J.; Clark, A. J.; Copperman, J.; Guenza, M. G., E-mail: mguenza@uoregon.edu [Department of Chemistry and Biochemistry, and Institute of Theoretical Science, University of Oregon, Eugene, Oregon 97403 (United States)

2014-05-28T23:59:59.000Z

304

Using Mesoscale Meteorological Models to Assess Wind Energy Potential.  

E-Print Network (OSTI)

??As the demand for safe and clean electricity increases, the New Zealand wind energy industry seems poised to expand. Many generating companies have projects in… (more)

Green, Michael Paul

2005-01-01T23:59:59.000Z

305

Analysis of Mesoscale Model Data for Wind Integration (Poster)  

SciTech Connect

Supports examination of implications of national 20% wind vision, and provides input to integration and transmission studies for operational impact of large penetrations of wind on the grid.

Schwartz, M.; Elliott, D.; Lew, D.; Corbus, D.; Scott, G.; Haymes, S.; Wan, Y. H.

2009-05-01T23:59:59.000Z

306

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

E-Print Network (OSTI)

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

Jun, Mikyoung

307

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

SciTech Connect

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

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

2011-03-20T23:59:59.000Z

308

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

E-Print Network (OSTI)

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

Sokolov, Andrei P.

309

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

SciTech Connect

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

Morrison, PI Hugh

2012-09-21T23:59:59.000Z

310

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

E-Print Network (OSTI)

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

2014-01-01T23:59:59.000Z

311

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

SciTech Connect

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

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

1993-12-01T23:59:59.000Z

312

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

Science Journals Connector (OSTI)

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

Wojciech M. Budzianowski

2013-01-01T23:59:59.000Z

313

A numerical study of mesoscale convection in a rotating tropical atmosphere  

E-Print Network (OSTI)

similar to the profile of a tropical disturbance. The meso-p forcing of convection consisted of' seven temperature perturbations con- fined below 2. 4 km at intervals of 8 km out to 60 km. The meso-9 forcing of convection comprised of a cosine thermal... perturbation field out to 75 km. Two different classes of simulations were performed. The first part explored how background vorticity affects convection generated by meso-7 and meso-9 forcing. The second part investigated how meso-9 forcing of convection...

Fitzpatrick, Patrick James

1992-01-01T23:59:59.000Z

314

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.

315

Mesoscale Convective Systems in Relation to African and Tropical Easterly Jets  

Science Journals Connector (OSTI)

This paper documents the interaction processes between mesoscale convective systems (MCS), the tropical easterly jet (TEJ), and the African easterly jet (AEJ) over West Africa during the monsoon peak of 2006 observed during the African Monsoon ...

L. Besson; Y. Lemaître

2014-09-01T23:59:59.000Z

316

Meso-scale eddies affect near-surface turbulent exchange: evidence from lidar and tower measurements  

Science Journals Connector (OSTI)

The eddy-covariance technique tends to underestimate the turbulent heat fluxes, which results in the non-closure of the surface energy balance. This study shows experimental evidence that meso-scale turbulent organized structures, which are ...

Fabian Eder; Marius Schmidt; Thomas Damian; Katja Träumner; Matthias Mauder

317

Evolution of Mesoscale Precipitation Band Environments within the Comma Head of Northeast U.S. Cyclones  

Science Journals Connector (OSTI)

This paper explores the mesoscale forcing and stability evolution of intense precipitation bands in the comma head sector of extratropical cyclones using the 32-km North American Regional Reanalysis, hourly 20-km Rapid Update Cycle analyses, and ...

David R. Novak; Brian A. Colle; Anantha R. Aiyyer

2010-06-01T23:59:59.000Z

318

Seasonal Mesoscale and Submesoscale Eddy Variability along the North Pacific Subtropical Countercurrent  

Science Journals Connector (OSTI)

Located at the center of the western North Pacific Subtropical Gyre, the Subtropical Countercurrent (STCC) is not only abundant in mesoscale eddies, but also exhibits prominent submesoscale eddy features. Output from a ° high-resolution OGCM ...

Bo Qiu; Shuiming Chen; Patrice Klein; Hideharu Sasaki; Yoshikazu Sasai

2014-12-01T23:59:59.000Z

319

A Climatology of Midlatitude Mesoscale Convective Vortices in the Rapid Update Cycle  

Science Journals Connector (OSTI)

Climatological characteristics of mesoscale convective vortices (MCVs) occurring in the state of Oklahoma during the late spring and summer of four years are investigated. The MCV cases are selected based on vortex detection by an objective ...

Eric P. James; Richard H. Johnson

2010-05-01T23:59:59.000Z

320

The supercell thunderstorm on 8 June 1990: Mesoscale analysis and radar observations  

Science Journals Connector (OSTI)

Surface mesoscale analysis helps to explain these different storm evolutions due to interaction among local circulations, Adriatic Sea and orography. While dry wind (foehn) dumps the thermodynamic instability in ...

P. P. Alberoni; S. Nanni; M. Crespi; M. Monai

1996-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "atmospheric mesoscale model" 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

Analysis of Strengthening and Dissipating Mesoscale Convective Systems Propagating off the West African Coast  

Science Journals Connector (OSTI)

A large number of Atlantic tropical depressions are generated in the eastern basin in relation to the African easterly wave (AEW) and embedded mesoscale convective systems (MCSs) coming from the African continent. In this paper, the structures of ...

Abdou L. Dieng; Laurence Eymard; Saidou M. Sall; Alban Lazar; Marion Leduc-Leballeur

2014-12-01T23:59:59.000Z

322

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

Science Journals Connector (OSTI)

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

Emily Rauscher; Kristen Menou

2013-01-01T23:59:59.000Z

323

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

324

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

E-Print Network (OSTI)

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

325

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

Science Journals Connector (OSTI)

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

Simon Grainger; Carsten S. Frederiksen; Xiaogu Zheng

2014-11-01T23:59:59.000Z

326

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

E-Print Network (OSTI)

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

Irwin, Mark E.

327

Musical Atmospherics  

Science Journals Connector (OSTI)

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

T. L. ECKERSLEY

1935-01-19T23:59:59.000Z

328

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

SciTech Connect

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

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

1998-06-01T23:59:59.000Z

329

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

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

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

330

ATMOSPHERIC ELSEVIER AtmosphericResearch40 (1996) 223-259  

E-Print Network (OSTI)

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

Mark, Pinsky

331

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

Science Journals Connector (OSTI)

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

2014-01-01T23:59:59.000Z

332

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

Science Journals Connector (OSTI)

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

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

2013-01-01T23:59:59.000Z

333

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

SciTech Connect

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

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

1997-11-01T23:59:59.000Z

334

ENSO Bred Vectors in Coupled Ocean–Atmosphere General Circulation Models  

Science Journals Connector (OSTI)

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

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

2006-04-01T23:59:59.000Z

335

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

Science Journals Connector (OSTI)

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

S. M. Perminov; V. N. Perminova…

1993-09-01T23:59:59.000Z

336

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

337

The influence of mesoscale eddies on shallow water acoustic propagation  

Science Journals Connector (OSTI)

Acoustic propagation measurements in 150 m depth on the Florida escarpment observe the effects of the passage of a cyclonic eddy. As the stream core of the Florida Current meanders the eddy is formed and propagates along the shelf edge. The sequence over a roughly a fortnight is as follows: ahead of the eddy warm surface water and cold bottom water are swept onto the terrace forming a steep thermocline and corresponding strong downward refracting C(z). The gradient produce intense focused RBR arrivals and the thermocline becomes a duct for internal waves to propagate shoreward. At first the internal wave energy is minimal and propagation is stable and coherent. As the internal tides attempt to propagate on shelf the sound speed field and the acoustic signals become increasingly variable. The variability reaches a crescendo as the 200 m long internal tide is blocked from propagating on to the narrower shelf and begins to break and overturn producing small?scale variability. As the eddy passes nearly iso?thermal conditions are restored along with quiescent internal wave fields and reduced signal variability. Here the effects are quantized with data from fixed?system acoustic and oceanographic measurements demonstrating that the mesoscale determines acoustic propagation conditions days in advance.

2003-01-01T23:59:59.000Z

338

Interpreting Temperature Strain Data from Meso-Scale Clathrate Experiments  

SciTech Connect

Gas hydrates are important in global climate change, carbon sequestra- tion, and seafloor stability. Currently, formation and dissociation pathways are poorly defined. We present a new approach for processing large amounts of data from meso-scale experiments, such as the LUNA distributed sensing system (DSS) in the seafloor process simulator (SPS) at Oak Ridge National Laboratory. The DSS provides a proxy for temperature measurement with a high spatial resolution allowing the heat of reaction during gas hydrate formation/dissociation to aid in locating clathrates in the vessel. The DSS fibers are placed in the sediment following an Archimedean spiral design and then the position of each sensor is solved by iterating over the arc length formula with Newtons method. The data is then gridded with 1 a natural neighbor interpolation algorithm to allow contouring of the data. The solution of the sensor locations is verified with hot and cold stimulus in known locations. An experiment was preformed with a vertically split column of sand and silt. The DSS system clearly showed hydrate forming in the sand first, then slowly creeping into the silt. Similar systems and data processing techniques could be used for monitoring of hydrates in natural environments or in any situation where a hybrid temperature/strain index is useful. Further ad- vances in fiber technology allow the fiber to be applied in any configuration and the position of each sensor to be precisely determined making practical applications easier.

Leeman, John R [ORNL; Rawn, Claudia J [ORNL; Ulrich, Shannon M [ORNL; Elwood Madden, Megan [University of Oklahoma, Norman; Phelps, Tommy Joe [ORNL

2012-01-01T23:59:59.000Z

339

MICRO-SEISMOMETERS VIA ADVANCED MESO-SCALE FABRICATION  

SciTech Connect

The Department of Energy (DOE) and the National Nuclear Security Administration (NNSA) seek revolutionary sensing innovations for the monitoring of nuclear detonations. Performance specifications are to be consistent with those obtainable by only an elite few products available today, but with orders of magnitude reduction in size, weight, power, and cost. The proposed commercial innovation calls upon several technologies including the combination of meso-scale fabrication and assembly, photonics-based displacement / motion detection methods, and the use of digital control electronics . Early Phase II development has demonstrated verified and repeatable sub 2ng noise floor from 3Hz to 100Hz, compact integration of 3-axis prototypes, and robust deployment exercises. Ongoing developments are focusing on low frequency challenges, low power consumption, ultra-miniature size, and low cross axis sensitivity. We are also addressing the rigorous set of specifications required for repeatable and reliable long-term explosion monitoring, including thermal stability, reduced recovery time from mass re-centering and large mechanical shocks, sensitivity stability, and transportability. Successful implementation will result in small, hand-held demonstration units with the ability to address national security needs of the DOE/NNSA. Additional applications envisioned include military/defense, scientific instrumentation, oil and gas exploration, inertial navigation, and civil infrastructure monitoring.

Garcia, Caesar A; Onaran, Guclu; Avenson, Brad; Hall, Neal

2014-11-07T23:59:59.000Z

340

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

SciTech Connect

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

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

2013-07-15T23:59:59.000Z

Note: This page contains sample records for the topic "atmospheric mesoscale model" 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

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

E-Print Network (OSTI)

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

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

2012-01-01T23:59:59.000Z

342

Operator-Split RungeKuttaRosenbrock Methods for Nonhydrostatic Atmospheric Models  

E-Print Network (OSTI)

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

Ullrich, Paul

343

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

Science Journals Connector (OSTI)

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

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

2010-06-01T23:59:59.000Z

344

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

Science Journals Connector (OSTI)

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

C. Giordano; J. Vernin; H. Vázquez Ramió; C. Muñoz-Tuñón; A. M. Varela; H. Trinquet

2013-01-01T23:59:59.000Z

345

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

Science Journals Connector (OSTI)

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

2009-01-01T23:59:59.000Z

346

Mesoscale Convective Vortices in Multiscale, Idealized Simulations: Dependence on Background State, Interdependency with Moist Baroclinic Cyclones, and Comparison with BAMEX Observations  

Science Journals Connector (OSTI)

A set of multiscale, nested, idealized numerical simulations of mesoscale convective systems (MCSs) and mesoscale convective vortices (MCVs) was conducted. The purpose of these simulations was to investigate the dependence of MCV development and ...

Robert J. Conzemius; Michael T. Montgomery

2010-04-01T23:59:59.000Z

347

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

348

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

SciTech Connect

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

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

2013-08-20T23:59:59.000Z

349

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

E-Print Network (OSTI)

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

Maine, University of

350

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

E-Print Network (OSTI)

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

Sun, Dezheng

351

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

SciTech Connect

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

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

2013-05-01T23:59:59.000Z

352

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

SciTech Connect

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

Hunter, C.

2012-03-28T23:59:59.000Z

353

Mesoscale Tank Experiments for Investigating Carbon Tetrachloride Biodegradation  

SciTech Connect

Mesoscale tank experiments were performed to simulate bioremediation of saturated zone carbon tetrachloride (CCl4) originating from a vadose zone carbon tetrachloride source. The mesoscale tank is 2-m wide by 2-m high by 3-m long and was constructed of stainless steel, yielding a total volume of 12 m3. Simulated geology within the tank consisted of two unconsolidated sand layers separated by a clay layer containing variable-sized stainless steel tubes that represented fractures within a consolidated porous medium. The thickness of the upper sand layer was approximately 55 cm, the thickness of the virtual fracture layer was 25 cm, and the thickness of the lower sand layer was approximately 98 cm. The water table was located at an elevation of approximately 54 cm from the bottom of the tank. CCl4 was added to the sealed tank by pouring 500 ml of neat CCl4 into a beaker buried approximately 10 cm below the upper sand surface through a stainless steel tube. The CCl4 was then allowed to partition through the reactor over time, eventually coming to equilibrium. Once CCl4 equilibrium had occurred in the saturated zone (~500 ppb); the reactor was bioaugmented with a CCl4 degrading culture enriched from the Subsurface Disposal Area at the INEEL. The culture was grown to a cell density of ~ 1.0 x 108 cells/ml and injected into the simulated aquifer through a center sampling port. Following injection of the culture, an initial aliquot of lactate (1,000 g/L), nitrogen, and phosphorus were added to the reactor. Lactate was injected every 3 – 5 days for one month. After 1 month of operation, a continuous supply of lactate (1,000 g/L) was pumped into the reactor at an average rate of 50 mL/min. CCl4 concentrations in the unsaturated zone were measured using hollow fiber membrane samplers, while liquid samples were analyzed to monitor levels in the simulated aquifer zone. Samples were also taken for analysis of volatile organic acids and cell density. As would be expected, increases in cell density over the length of the cell correlated with the flow of the water through the cell. One week following injection microbes and lactate, cell numbers were in the range of 5.0 x 106 cells/mL, by the end of the experiment cell numbers had increased to approximately 1.94 x 107 cells/mL. Five days after lactate injection was initiated, chloroform appeared in liquid samples taken for chlorinated VOC analysis. CCl4 concentrations in the liquid phase dropped to approximately 180 ppb. At the conclusion of the batch lactate injection phase of the bioaugmentation, CCl4 levels averaged 40 ppb and chloroform levels averaged 44 ppb. Interestingly, once continuous lactate addition was initiated, CCl4 concentrations in the saturated zone increased with spikes as high as 3,000 ppb. Chloroform concentrations also increased following continuous addition of lactate. Since the CCl4 source in the breaker had been depleted, vadose zone concentrations of CCl4 dropped steadily during addition of lactate to the saturated zone. CCl4 levels of ~ 800 ppmv were noted at the beginning of the experiment, levels decreased to below 200 ppmv by the end of the bioaugmentation phase. No chloroform was noted in the vadose zone during testing.

Brady D. Lee; Robert J. Lenhard

2005-06-01T23:59:59.000Z

354

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

SciTech Connect

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

Bird, R.; Riordan, C.

1984-12-01T23:59:59.000Z

355

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

SciTech Connect

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

Keeling, Ralph [UCSD-SIO

2014-12-12T23:59:59.000Z

356

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

SciTech Connect

Systems designed to monitor airborne radionuclides released from underground nuclear explosions detected radioactive fallout from the Fukushima Daiichi nuclear accident in March 2011. Atmospheric transport modeling (ATM) of plumes of noble gases and particulates were performed soon after the accident to determine plausible detection locations of any radioactive releases to the atmosphere. We combine sampling data from multiple International Modeling System (IMS) locations in a new way to estimate the magnitude and time sequence of the releases. Dilution factors from the modeled plume at five different detection locations were combined with 57 atmospheric concentration measurements of 133-Xe taken from March 18 to March 23 to estimate the source term. This approach estimates that 59% of the 1.24×1019 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

357

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

Science Journals Connector (OSTI)

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

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

2007-01-01T23:59:59.000Z

358

The VAMOS Ocean-Cloud-Atmosphere-Land Study Regional Experiment (VOCALS-REx): Goals, platforms, and field operations  

SciTech Connect

The VAMOS Ocean-Cloud-Atmosphere-Land Study Regional Experiment (VOCALS-REx) was an international field program designed to make observations of poorly understood but critical components of the coupled climate system of the southeast Pacific. This region is characterized by strong coastal upwelling, the coolest SSTs in the tropical belt, and is home to the largest subtropical stratocumulus deck on Earth. The field intensive phase of VOCALS-REx took place during October and November 2008 and constitutes a critical part of a broader CLIVAR program (VOCALS) designed to develop and promote scientific activities leading to improved understanding, model simulations, and predictions of the southeastern Pacific (SEP) coupled ocean-atmosphere-land system, on diurnal to interannual timescales. The other major components of VOCALS are a modeling program with a model hierarchy ranging from the local to global scales, and a suite of extended observations from regular research cruises, instrumented moorings, and satellites. The two central themes of VOCALS-REx focus upon (a) links between aerosols, clouds and precipitation and their impacts on marine stratocumulus radiative properties, and (b) physical and chemical couplings between the upper ocean and the lower atmosphere, including the role that mesoscale ocean eddies play. A set of hypotheses designed to be tested with the combined field, monitoring and modeling work in VOCALS is presented here. A further goal of VOCALS-REx is to provide datasets for the evaluation and improvement of large-scale numerical models. VOCALS-REx involved five research aircraft, two ships and two surface sites in northern Chile. We describe the instrument payloads and key mission strategies for these platforms and give a summary of the missions conducted.

Wood, R.; Springston, S.; Mechoso, C. R.; Bretherton, C. S.; A.Weller, R.; Huebert, B.; Straneo, F.; Albrecht, B. A.; Coe, H.; Allen, G.; Vaughan, G.; Daum, P.; Fairall, C.; Chand, D.; Klenner, L. G.; Garreaud, R.; Grados, C.; Covert, D. S.; Bates, T. S.; Krejci, R.; Russell, L. M.; Szoeke, S. d.; Brewer, A.; Yuter, S. E.; Chaigneau, A.; Toniazzo, T.; Minnis, P.; Palikonda, R.; Abel, S. J.; Brown, W. O. J.; Williams, S.; Fochesatto, J.; Brioude, J.; Bower, K. N

2011-01-21T23:59:59.000Z

359

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

SciTech Connect

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

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

1996-01-01T23:59:59.000Z

360

Lattice Boltzmann models for non-Newtonian flows  

Science Journals Connector (OSTI)

......Issue: Modelling the mesoscale Lattice Boltzmann models for non-Newtonian flows...road, Chester CH1 4BJ, UK The lattice Boltzmann method has been established...the case of inelastic fluids. lattice Boltzmann methods|non-Newtonian fluids......

T. N. Phillips; G. W. Roberts

2011-10-01T23:59:59.000Z

Note: This page contains sample records for the topic "atmospheric mesoscale model" 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

Formation of Meso-Scale Roughening in 6022-T4 Al Sheets Deformed in Plane-Strain Tension  

E-Print Network (OSTI)

Meso-scale surface roughening evolution in 6022-T4 Al sheets was investigated using plane-strain tension. Formation of grain-scale hills and valleys and their relation to the morphologies and corresponding orientations of surface grains after deformation were examined experimentally. These observations were analyzed using various approaches based on the Schmid and Taylor crystal plasticity models. It was observed that surface grains with and without slip bands tend to form valleys and hills, respectively, wherever these two types of grains are adjacent to each other along the planestrain tension direction. When the sample was pulled along the transverse direction, the formation of hills and valleys by unbanded and banded grains was more lineally organized in the plane-strain (rolling) direction than in the sample which was pulled along the rolling direction. Slip banding and valley formation were principally observed in the surface grains with either very few (1?2) slip systems of high Schmid factors or low Taylor factors, in contrast to non slip-banded and hillforming surface grains. Quantitative analysis using correlation coefficients showed that the Schmid factor provided slightly better agreement than the Taylor factor in predicting slip-banding (and valley-forming) and non slip-banding (and hill-forming) behaviors of surface grains. In addition, measures that quantify the image qualities of EBSPs for selected surface grains suggested that the slip-banded and valley-forming grains contain less lattice distortion than the non slip-banded and Currently at Department of Civil and Environmental Engineering, Carnegie Mellon University, PAhill-forming grains despite the larger strains experienced by these grains. This indicates that dislocations in the slip-banded grains move out of the surface to create deformation without lattice distortion. Plastic interactions between specific neighboring grains are central to the formation of meso-scale surface roughening. 1.

unknown authors

362

Atmospheric tritium  

SciTech Connect

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

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

1980-01-01T23:59:59.000Z

363

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

Science Journals Connector (OSTI)

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

Marcelo Chamecki; Charles Meneveau; Marc B. Parlange

2007-06-01T23:59:59.000Z

364

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.

365

EMSL: Science: Atmospheric Aerosol Systems  

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

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

366

High altitude atmospheric discharges according to the runaway air breakdown mechanism  

SciTech Connect

High altitude optical transients - red sprites, blue jets, and elves - are modeled in the context of the relativistic electron runaway air breakdown mechanism. These emissions are usually associated with large mesoscale convective systems (hereafter MCS). In thunderstorms cloud electrification proceeds over a time scale long enough to permit the conducting atmosphere above the cloud to polarize and short out the thunderstorm electric field. When a lightning strike rapidly neutralizes a cloud charge layer runaway driving fields can develop in the stratosphere and mesosphere. According to present simulations of the full runaway process the variety of observed optical emissions are due to the nature of the normal lightning event in the MCS that kick starts the runaway avalanche. In this paper the authors describe some details of the model, present the results of the evolution of the primary electron population, and summarize the initial conditions necessary for different types of discharges. Two companion papers present (a) the predicted optical, gamma ray, and radio emissions caused by these electrical discharges, and (b) the time evolution of the secondary electron population and its implications in terms of observables.

Symbalisty, E.; Roussel-Dupre, R.; Yukhimuk, V.; Taranenko, Y.

1997-04-01T23:59:59.000Z

367

Meso-Scale Planning for Multi-Agent Navigation Liang He Jur van den Berg  

E-Print Network (OSTI)

Meso-Scale Planning for Multi-Agent Navigation Liang He Jur van den Berg Abstract-- We introduce are with the of School of Computing, University of Utah. E-mail: lianghe.hust@gmail.com, berg@cs.utah.edu. Fig. 1

van den Berg, Jur

368

Mesoscale energetics and ows induced by sea-land and mountain-valley contrasts  

E-Print Network (OSTI)

Mesoscale energetics and ¯ows induced by sea-land and mountain-valley contrasts S. Federico1 , G. A October 1999 Abstract. We study the relative importance of sea-land and mountain-valley thermal contrasts and the west-facing slopes in the afternoon. The local thermally driven winds follow the development

Paris-Sud XI, Université de

369

Larval fish assemblages and mesoscale oceanographic structure along the Mesoamerican Barrier Reef System  

E-Print Network (OSTI)

Larval fish assemblages and mesoscale oceanographic structure along the Mesoamerican Barrier Reef Caribbean region, and contains spawning sites for a number of reef fish species. Despite this, little is known of the distribution and transport of pelagic fish larvae in the area, and basic in situ

370

Parameterized Mesoscale Forcing Mechanisms for Initiating Numerically Simulated Isolated Multicellular Convection  

E-Print Network (OSTI)

Multicellular Convection ADRIAN M. LOFTUS* School of Meteorology, University of Oklahoma, Norman, Oklahoma DANIEL B. WEBER Center for Analysis and Prediction of Storms, University of Oklahoma, Norman, Oklahoma CHARLES A. DOSWELL III Cooperative Institute for Mesoscale Meteorological Studies, University of Oklahoma

Doswell III, Charles A.

371

Evaluation of mesoscale convective systems in South America using multiple satellite products and an objectbased approach  

E-Print Network (OSTI)

Evaluation of mesoscale convective systems in South America using multiple satellite products­2003 in the La Plata river basin, southeastern South America, were analyzed with the Contiguous Rain Area (CRA; Salby and Callaghan, 1997]. However, in South America, few studies have assessed the validity

Ebert, Beth

372

Radar, satellite, and lightning characteristics of select mesoscale convective systems in Texas  

E-Print Network (OSTI)

This study compares radar data from the League City, Texas WSR-88D and cloud-to-ground (CG) lightning data for a set of eight mesoscale convective systems (MCSs) which occur at various stages of development along the upper Texas Gulf Coast. Vertical...

Toracinta, Ernest Richard

2012-06-07T23:59:59.000Z

373

The Tilt of the Leading Edge of Mesoscale Tropical Convective Lines  

Science Journals Connector (OSTI)

The tilt with height of the leading edge of seven mesoscale convective lines in GATE is determined by two independent methods. When averaged over time and along the line axis, the tilt is found to he surprisingly shallow, between 20 and 35 ...

M. A. LeMone; G. M. Barnes; E. J. Szoke; E. J. Zipser

1984-03-01T23:59:59.000Z

374

Mesoscale Convective Systems and Their Synoptic-scale Environment in Finland  

Science Journals Connector (OSTI)

The environments which high-latitude intense and non-intense mesoscale convective systems (iMCSs and niMCSs) and smaller thunderstorm clusters (subMCS) develop in were studied using proximity soundings. Eight-year MCS statistics were created by ...

ARI-JUHANI PUNKKA; MARJA BISTER

375

Radar range measurements in the atmosphere.  

SciTech Connect

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

Doerry, Armin Walter

2013-02-01T23:59:59.000Z

376

Mesoscale Simulations of a Wind Ramping Event for Wind Energy Prediction  

SciTech Connect

Ramping events, or rapid changes of wind speed and wind direction over a short period of time, present challenges to power grid operators in regions with significant penetrations of wind energy in the power grid portfolio. Improved predictions of wind power availability require adequate predictions of the timing of ramping events. For the ramping event investigated here, the Weather Research and Forecasting (WRF) model was run at three horizontal resolutions in 'mesoscale' mode: 8100m, 2700m, and 900m. Two Planetary Boundary Layer (PBL) schemes, the Yonsei University (YSU) and Mellor-Yamada-Janjic (MYJ) schemes, were run at each resolution as well. Simulations were not 'tuned' with nuanced choices of vertical resolution or tuning parameters so that these simulations may be considered 'out-of-the-box' tests of a numerical weather prediction code. Simulations are compared with sodar observations during a wind ramping event at a 'West Coast North America' wind farm. Despite differences in the boundary-layer schemes, no significant differences were observed in the abilities of the schemes to capture the timing of the ramping event. As collaborators have identified, the boundary conditions of these simulations probably dominate the physics of the simulations. They suggest that future investigations into characterization of ramping events employ ensembles of simulations, and that the ensembles include variations of boundary conditions. Furthermore, the failure of these simulations to capture not only the timing of the ramping event but the shape of the wind profile during the ramping event (regardless of its timing) indicates that the set-up and execution of such simulations for wind power forecasting requires skill and tuning of the simulations for a specific site.

Rhodes, M; Lundquist, J K

2011-09-21T23:59:59.000Z

377

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

SciTech Connect

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

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

1999-06-01T23:59:59.000Z

378

DE-SC0001933 DOE Final Report  

SciTech Connect

The overall objective of this study was to improve the representation of regional ocean circulation in the North Pacific by using high resolution atmospheric forcing that accurately represents mesoscale processes in ocean-atmosphere regional (North Pacific) model configuration. The goal was to assess the importance of accurate representation of mesoscale processes in the atmosphere and the ocean on large scale circulation. This is an important question, as mesoscale processes in the atmosphere which are resolved by the high resolution mesoscale atmospheric models such as Weather Research and Forecasting (WRF), are absent in commonly used atmospheric forcing such as CORE forcing, employed in e.g. the Community Climate System Model (CCSM).

Cerovecki, Ivana

2014-11-14T23:59:59.000Z

379

Lifetimes and time scales in atmospheric chemistry  

Science Journals Connector (OSTI)

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

2007-01-01T23:59:59.000Z

380

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

Note: This page contains sample records for the topic "atmospheric mesoscale model" 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

Frigatebird behaviour at the ocean–atmosphere interface: integrating animal behaviour with multi-satellite data  

Science Journals Connector (OSTI)

...animal behaviour with multi-satellite data Silvia De Monte 1 2 3...nonlinear analysis of multi-satellite data. We find that frigatebirds...often referred to as the ocean weather and covers the mesoscale and...related to phytoplankton. Satellite, in situ and model data show...

2012-01-01T23:59:59.000Z

382

Modeling, Analysis and Simulation of Multiscale Preferential Flow - 8/05-8/10 - Final Report  

SciTech Connect

The research agenda of this project are: (1) Modeling of preferential transport from mesoscale to macroscale; (2) Modeling of fast flow in narrow fractures in porous media; (3) Pseudo-parabolic Models of Dynamic Capillary Pressure; (4) Adaptive computational upscaling of flow with inertia from porescale to mesoscale; (5) Adaptive modeling of nonlinear coupled systems; and (6) Adaptive modeling and a-posteriori estimators for coupled systems with heterogeneous data.

Ralph Showalter; Malgorzata Peszynska

2012-07-03T23:59:59.000Z

383

The evolution of total lightning and radar reflectivity characteristics of two mesoscale convective systems over Houston, Texas  

E-Print Network (OSTI)

Two mesoscale convective systems (MCSs) passed over the Houston Lightning Detection and Ranging (LDAR) network on 31 October 2005 and 21 April 2006. As the MCSs traverse the LDAR network, the systems slowly mature with a weakening convective line...

Hodapp, Charles Lee

2009-05-15T23:59:59.000Z

384

Evaluation of Ensemble Configurations for the Analysis and Prediction of Heavy-Rain-Producing Mesoscale Convective Systems  

Science Journals Connector (OSTI)

This study investigates probabilistic forecasts made using different convection-allowing ensemble configurations for a three-day period in June 2010 when numerous heavy-rain-producing mesoscale convective systems (MCSs) occurred in the United ...

Russ S. Schumacher; Adam J. Clark

2014-11-01T23:59:59.000Z

385

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

SciTech Connect

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

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

1999-08-01T23:59:59.000Z

386

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

Science Journals Connector (OSTI)

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

Paul H. Hiemstra; Derek Karssenberg; Arjan van Dijk

2011-01-01T23:59:59.000Z

387

A Statistical Analysis of Characteristics of Mesoscale Convective System Mountain Initiation Location Clusters in the Arkansas-Red River Basin  

E-Print Network (OSTI)

A Statistical Analysis of Characteristics of Mesoscale Convective System Mountain Initiation Location Clusters in the Arkansas-Red River Basin By Elisabeth F. Callen Submitted to the graduate degree program in Geography and the Graduate... ____________________________________ David Mechem Date Defended: November 9, 2012 ii The Thesis Committee for Elisabeth F. Callen certifies that this is the approved version of the following thesis: A Statistical Analysis of Characteristics of Mesoscale Convective...

Callen, Elisabeth F.

2012-12-31T23:59:59.000Z

388

Initial Testing of a Numerical Ocean Circulation Model Using a Hybrid (Quasi-Isopycnic) Vertical Coordinate  

Science Journals Connector (OSTI)

An ocean circulation model, developed for the study of mesoscale to gyre-scale circulation and heat transport, is described and tested. The model employs density as vertical coordinate except in the immediate vicinity of possible coordinate ...

Rainer Bleck; Douglas B. Boudra

1981-06-01T23:59:59.000Z

389

AN ANALYSIS OF THE PULSATING STAR SDSS J160043.6+074802.9 USING NEW NON-LTE MODEL ATMOSPHERES AND SPECTRA FOR HOT O SUBDWARFS  

SciTech Connect

We first present our new grids of model atmospheres and spectra for hot subdwarf O (sdO) stars: standard non-LTE (NLTE) H+He models with no metals, NLTE line-blanketed models with C+N+O, and NLTE line-blanketed models with C+N+O+Fe. Using hydrogen and helium lines in the optical range, we make detailed comparisons between theoretical spectra of different grids in order to characterize the line-blanketing effects of metals. We find these effects to be dependent on both the effective temperature and the surface gravity. Moreover, we find that the helium abundance also influences in an important way the effects of line blanketing on the resulting spectra. We further find that the addition of Fe (solar abundance) leads only to incremental effects on the atmospheric structure as compared with the case where the metallicity is defined by C+N+O (solar abundances). We use our grids to perform fits on a 9 A resolution, high signal-to-noise ratio ({approx}300 blueward of 5000 A) optical spectrum of SDSS J160043.6+074802.9, the only known pulsating sdO star. Our best and most reliable result is based on the fit achieved with NLTE synthetic spectra that include C, N, O, and Fe in solar abundances, leading to the following parameters: T{sub eff} = 68,500 {+-} 1770 K, log g = 6.09 {+-} 0.07, and log N(He)/N(H) = -0.64 {+-} 0.05 (formal fitting errors only). This combination of parameters, particularly the comparatively high helium abundance, implies that line-blanketing effects due to metals are not very large in the atmosphere of this sdO star.

Latour, M.; Fontaine, G.; Brassard, P. [Departement de Physique, Universite de Montreal, Succ. Centre-Ville, C. P. 6128, Montreal, QC H3C 3J7 (Canada); Green, E. M. [Steward Observatory, University of Arizona, 933 North Cherry Avenue, Tucson, AZ 85721 (United States); Chayer, P. [Space Telescope Science Institute, 3700 San Martin Drive, Baltimore, MD 21218 (United States); Randall, S. K., E-mail: fontaine@astro.umontreal.ca [European Southern Observatory, Karl-Schwarzschild-Str. 2, 85748 Garching (Germany)

2011-06-01T23:59:59.000Z

390

Transient response of the Hadley Centre coupled ocean-atmosphere model to increasing carbon dioxide. Part I: Control climate and flux adjustment  

SciTech Connect

This paper describes the initialization of an experiment to study the time-dependent response of a high-resolution global coupled ocean-atmosphere general circulation model to a gradual increase in carbon dioxide. The stability of the control integration with respect to climate drift is assessed, and aspects of the model climatology relevant to the simulation of climate change are discussed. The observed variation of oceanic temperature with latitude and depth is basically well simulated, although, in common with other ocean models, the main thermocline is too diffuse. Nevertheless, it is found that large heat and water flux adjustments must be added to the surface layer of the ocean in order to prevent the occurrence of unacceptable climate drift. The ocean model appears to achieve insufficient meridional heat transport, and this is supported by the pattern of the heat flux adjustment term, although errors in the simulated atmosphere-ocean heat flux also contribute to the latter. The application of the flux adjustments restricts climate drift during the 75-year control experiment. However, a gradual warming still occurs in the surface layers of the Southern Ocean because the flux adjustments are inserted as additive terms in this integration and cannot therefore be guaranteed to prevent climate drift completely. 68 refs., 29 figs., 1 tab.

Murphy, J.M. [Hadley Centre for Climate Prediction and Research, Bracknell (United Kingdom)] [Hadley Centre for Climate Prediction and Research, Bracknell (United Kingdom)

1995-01-01T23:59:59.000Z

391

The Dynamics of Deterministic Chaos in Numerical Weather Prediction Models  

E-Print Network (OSTI)

Atmospheric weather systems are coherent structures consisting of discrete cloud cells forming patterns of rows/streets, mesoscale clusters and spiral bands which maintain their identity for the duration of their appreciable life times in the turbulent shear flow of the planetary Atmospheric Boundary Layer. The existence of coherent structures (seemingly systematic motion) in turbulent flows has been well established during the last 20 years of research in turbulence. Numerical weather prediction models based on the inherently non-linear Navier-Stokes equations do not give realistic forecasts because of the following inherent limitations: (1) the non-linear governing equations for atmospheric flows do not have exact analytic solutions and being sensitive to initial conditions give chaotic solutions characteristic of deterministic chaos (2) the governing equations do not incorporate the dynamical interactions and co-existence of the complete spectrum of turbulent fluctuations which form an integral part of the large coherent weather systems (3) limitations of available computer capacity necessitates severe truncation of the governing equations, thereby generating errors of approximations (4) the computer precision related roundoff errors magnify the earlier mentioned uncertainties exponentially with time and the model predictions become unrealistic. The accurate modelling of weather phenomena therefore requires alternative concepts and computational techniques. In this paper a universal theory of deterministic chaos applicable to the formation of coherent weather structures in the ABL is presented.

A. Mary Selvam

2003-10-07T23:59:59.000Z

392

An investigation of the rainfall distribution of a mesoscale network in Ecuador  

E-Print Network (OSTI)

provides a preliminary investigation of the mesoscale rainfall distribution of two geographical areas. The spatial distribution of rainfall at San Carlos, Ecuador, is compared with the spatial distribution at Riesel, Texas. This study is based upon..., 1964) at San Carlos and the daily rainfall of the 1960-1964 warm seasons (May through September) at Riesel. The isohyetal patterns and the depth-area relations show that rainfall often varies greatly over short dis- tances. A relationship exists...

Guest, Tommy Dean

2012-06-07T23:59:59.000Z

393

DOE research on atmospheric aerosols  

SciTech Connect

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

Schwartz, S.E.

1995-11-01T23:59:59.000Z

394

Evaluation of A New Mixed-Phase Cloud Microphysics Parameterization with the NCAR Climate Atmospheric Model (CAM3) and ARM Observations Fourth Quarter 2007 ARM Metric Report  

SciTech Connect

Mixed-phase clouds are composed of a mixture of cloud droplets and ice crystals. The cloud microphysics in mixed-phase clouds can significantly impact cloud optical depth, cloud radiative forcing, and cloud coverage. However, the treatment of mixed-phase clouds in most current climate models is crude and the partitioning of condensed water into liquid droplets and ice crystals is prescribed as temperature dependent functions. In our previous 2007 ARM metric reports a new mixed-phase cloud microphysics parameterization (for ice nucleation and water vapor deposition) was documented and implemented in the NCAR Community Atmospheric Model Version 3 (CAM3). The new scheme was tested against the Atmospheric Radiation Measurement (ARM) Mixed-phase Arctic Cloud Experiment (M-PACE) observations using the single column modeling and short-range weather forecast approaches. In this report this new parameterization is further tested with CAM3 in its climate simulations. It is shown that the predicted ice water content from CAM3 with the new parameterization is in better agreement with the ARM measurements at the Southern Great Plain (SGP) site for the mixed-phase clouds.

X Liu; SJ Ghan; S Xie; J Boyle; SA Klein

2007-09-30T23:59:59.000Z

395

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

SciTech Connect

A regional atmosphere model [Weather Research and Forecasting model version 3 (WRF3)] and a land surface model [Community Land Model, version 3.5 (CLM3.5)] were coupled to study the interactions between the atmosphere and possible future California land-cover changes. The impact was evaluated on California's climate of changes in natural vegetation under climate change and of intentional afforestation. The ability of WRF3 to simulate California's climate was assessed by comparing simulations by WRF3-CLM3.5 and WRF3-Noah to observations from 1982 to 1991. Using WRF3-CLM3.5, the authors performed six 13-yr experiments using historical and future large-scale climate boundary conditions from the Geophysical Fluid Dynamics Laboratory Climate Model version 2.1 (GFDL CM2.1). The land-cover scenarios included historical and future natural vegetation from the Mapped Atmosphere-Plant-Soil System-Century 1 (MC1) dynamic vegetation model, in addition to a future 8-million-ha California afforestation scenario. Natural vegetation changes alone caused summer daily-mean 2-m air temperature changes of -0.7 to +1 C in regions without persistent snow cover, depending on the location and the type of vegetation change. Vegetation temperature changes were much larger than the 2-m air temperature changes because of the finescale spatial heterogeneity of the imposed vegetation change. Up to 30% of the magnitude of the summer daily-mean 2-m air temperature increase and 70% of the magnitude of the 1600 local time (LT) vegetation temperature increase projected under future climate change were attributable to the climate-driven shift in land cover. The authors projected that afforestation could cause local 0.2-1.2 C reductions in summer daily-mean 2-m air temperature and 2.0-3.7 C reductions in 1600 LT vegetation temperature for snow-free regions, primarily because of increased evapotranspiration. Because some of these temperature changes are of comparable magnitude to those projected under climate change this century, projections of climate and vegetation change in this region need to consider these climate-vegetation interactions.

Subin, Z.M.; Riley, W.J.; Kueppers, L.M.; Jin, J.; Christianson, D.S.; Torn, M.S.

2010-11-01T23:59:59.000Z

396

North Pacific Mesoscale Coupled Air-Ocean Simulations Compared with Observations  

SciTech Connect

Executive summary The main objective of the study was to investigate atmospheric and ocean interaction processes in the western Pacific and, in particular, effects of significant ocean heat loss in the Kuroshio and Kuroshio Extension regions on the lower and upper atmosphere. It is yet to be determined how significant are these processes are on climate scales. The understanding of these processes led us also to development of the methodology of coupling the Weather and Research Forecasting model with the Parallel Ocean Program model for western Pacific regional weather and climate simulations. We tested NCAR-developed research software Coupler 7 for coupling of the WRF and POP models and assessed its usability for regional-scale applications. We completed test simulations using the Coupler 7 framework, but implemented a standard WRF model code with options for both one- and two-way mode coupling. This type of coupling will allow us to seamlessly incorporate new WRF updates and versions in the future. We also performed a long-term WRF simulation (15 years) covering the entire North Pacific as well as high-resolution simulations of a case study which included extreme ocean heat losses in the Kuroshio and Kuroshio Extension regions. Since the extreme ocean heat loss occurs during winter cold air outbreaks (CAO), we simulated and analyzed a case study of a severe CAO event in January 2000 in detail. We found that the ocean heat loss induced by CAOs is amplified by additional advection from mesocyclones forming on the southern part of the Japan Sea. Large scale synoptic patterns with anomalously strong anticyclone over Siberia and Mongolia, deep Aleutian Low, and the Pacific subtropical ridge are a crucial setup for the CAO. It was found that the onset of the CAO is related to the breaking of atmospheric Rossby waves and vertical transport of vorticity that facilitates meridional advection. The study also indicates that intrinsic parameterization of the surface fluxes within the WRF model needs more evaluation and analysis.

Koracin, Darko; Cerovecki, Ivana; Vellore, Ramesh; Mejia, John; Hatchett, Benjamin; McCord, Travis; McLean, Julie; Dorman, Clive

2013-04-11T23:59:59.000Z

397

Numerical Simulation in Applied Geophysics. From the Mesoscale to ...  

E-Print Network (OSTI)

Instead of solving the global problem associated with the above model, we obtained the solution using a parallel FE ... Black-Oil simulator. .... used in hydrocarbon exploration geophysics, mining and reservoir characterization and production.

398

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

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

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

399

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

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

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

400

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

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

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

Note: This page contains sample records for the topic "atmospheric mesoscale model" 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

alberta-98.pdf  

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

profiles are based on the National Weather Service (NWS) Eta mesoscale model Data Assimilation System (EDAS), which used standard 12-hourly radiosondes; 3) the "atmospheric...

402

Evaluation of Preindustrial to Present-day Black Carbon and its Albedo Forcing from Atmospheric Chemistry and Climate Model Intercomparison Project (ACCMIP)  

SciTech Connect

As a part of the Atmospheric Chemistry and Climate Model Intercomparison Project (ACCMIP), we evaluate the historical black carbon (BC) aerosols simulated by 8 ACCMIP models against the observations including 12 ice core records, a long-term surface mass concentrations and recent Arctic BC snowpack measurements. We also estimate BC albedo forcing by performing additional simulations using the NCAR Community Land and Sea-Ice model 4 with prescribed meteorology from 1996-2000, which includes the SNICAR BC-snow model. We evaluated the vertical profile of BC snow concentrations from these offline simulations to using recent BC snowpack measurements. Despite using the same BC emissions, global BC burden differs by approximately a factor of 3 among models due to the differences in aerosol removal parameterizations and simulated meteorology among models; 34 Gg to 103 Gg in 1850 and 82 Gg to 315 Gg in 2000. However,models agree well on 2.5~3 times increase in the global BC burden from preindustrial to present-day, which matches with the 2.5 times increase in BC emissions. We find a large model diversity at both NH and SH high latitude regions for BC burden and at SH high latitude regions for deposition fluxes. The ACCMIP simulations match the observed BC mass concentrations well in Europe and North America except at Jungfrauch and Ispra. However, the models fail to capture the Arctic BC seasonality due tosevere underestimations during winter and spring. Compared to recent snowpack measurements, the simulated vertically resolved BC snow concentrations are, on average, within a factor of 2-3 of observations except for Greenland and Arctic Ocean. However, model and observation differ widely due to missing interannual variations in emissions and possibly due to the choice of the prescribed meteorology period (i.e., 1996-2000).

Lee, Y. H.; Lamarque, J.-F.; Flanner, M. G.; Jiao, C.; Shindell, Drew; Berntsen, T.; Bisiauxs, M.; Cao, J.; Collins, W. J.; Curran, M.; Edwards, R.; Faluvegi, G.; Ghan, Steven J.; Horowitz, L.; McConnell, J.R.; Ming, J.; Myhre, G.; Nagashima, T.; Naik, Vaishali; Rumbold, S.; Skeie, R. B.; Sudo, K.; Takemura, T.; Thevenon, F.; Xu, B.; Yoon, Jin-Ho

2013-03-05T23:59:59.000Z

403

Mesoscale Variations of the Atmospheric Snow Line over the Northern Sierra Nevada: Multiyear Statistics, Case Study, and Mechanisms  

E-Print Network (OSTI)

Division, NOAA/ESRL, Boulder, Colorado (Manuscript received 6 July 2012, in final form 27 September 2012, New Haven, Connecticut DAVID E. KINGSMILL CIRES, University of Colorado, and Physical Sciences navigability, river runoff, freshwater resources, and hazards from landslides, av- alanches, and floods

Minder, Justin

404

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

405

High-Resolution Large-Eddy Simulations of Scalar Transport in Atmospheric Boundary Layer Flow over Complex Terrain  

E-Print Network (OSTI)

of Electric Power Industry, Chiba, Japan FOTINI KATOPODES CHOW Department of Civil and Environmental to the choice of numerical simulation parameters than is typically needed for mean wind field predictions. Large-eddy simulation is used in a mesoscale setting, providing modeling advantages through the use of robust turbulence

Chow, Fotini Katopodes

406

ADVANCES IN ATMOSPHERIC SCIENCES, VOL. 25, NO. 1, 2008, 1123 Total Deformation and its Role in Heavy Precipitation Events  

E-Print Network (OSTI)

Research and Forecasting (WRF) model output data. It is found that right before the occurrence of the terms shows that the pressure gradient plays a major role in determining the local change of total and wind velocity, only wind velocity is a vector. At the mesoscale, where the characteristic scale is less

Xue, Ming

407

A three–dimensional lattice–gas model for amphiphilic fluid dynamics  

Science Journals Connector (OSTI)

...it is implemented using high-performance computing and visualization techniques...mesoscale modelling|high-performance computing|lattice gas|amphiphilic...is imple- mented using high-performance computing and visualization techniques...

2000-01-01T23:59:59.000Z

408

A Modeling Study of Circulation and Eddies in the Persian Gulf  

Science Journals Connector (OSTI)

The circulation and mesoscale eddies in the Persian Gulf are investigated using results from a high-resolution (?1 km) Hybrid Coordinate Ocean Model (HYCOM). The circulation in the Persian Gulf is composed of two spatial scales: basin scale and ...

Prasad G. Thoppil; Patrick J. Hogan

2010-09-01T23:59:59.000Z

409

Diurnal cycle of air pollution in the Kathmandu Valley, Nepal: 2. Modeling results  

E-Print Network (OSTI)

After completing a 9-month field experiment studying air pollution and meteorology in the Kathmandu Valley, Nepal, we set up the mesoscale meteorological model MM5 to simulate the Kathmandu Valley's meteorology with a ...

Panday, Arnico K.

410

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

SciTech Connect

One key question regarding current climate models is whether the projection of climate extremes converges to a realistic representation as the spatial and temporal resolutions of the model are increased. Ideally the model extreme statistics should approach a fixed distribution once the resolutions are commensurate with the characteristic length and time scales of the processes governing the formation of the extreme phenomena of interest. In this study, a series of AGCM runs with idealized 'aquaplanet-steady-state' boundary conditions have been performed with the Community Atmosphere Model CAM3 to investigate the effect of horizontal resolution on climate extreme simulations. The use of the aquaplanet framework highlights the roles of model physics and dynamics and removes any apparent convergence in extreme statistics due to better resolution of surface boundary conditions and other external inputs. Assessed at a same large spatial scale, the results show that the horizontal resolution and time step have strong effects on the simulations of precipitation extremes. The horizontal resolution has a much stronger impact on precipitation extremes than on mean precipitation. Updrafts are strongly correlated with extreme precipitation at tropics at all the resolutions, while positive low-tropospheric temperature anomalies are associated with extreme precipitation at mid-latitudes.

Li, F.; Collins, W.D.; Wehner, M.F.; Williamson, D.L.; Olson, J.G.; Algieri, C.

2011-03-01T23:59:59.000Z

411

Composition and Reactions of Atmospheric Aerosol Particles  

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

Composition and Reactions of Composition and Reactions of Atmospheric Aerosol Particles Composition and Reactions of Atmospheric Aerosol Particles Print Wednesday, 29 June 2005 00:00 Microscopic aerosol particles in the atmosphere contain carbonaceous components from mineral dust and combustion emissions released from around the world. How long these tiny particles remain in the atmosphere can have a huge impact on the global climate. Measurements based on high-resolution scanning transmission x-ray images obtained at the ALS have revealed chemical reactions on and in atmospheric aerosol particles that caused particle growth while changing organic composition by 13 to 24% per day, an oxidation rate significantly slower than is currently used in atmospheric models. Since oxidation has a strong effect on particle lifetime in the atmosphere, these results will help climate scientists refine the computer models used to predict climate change.

412

Composition and Reactions of Atmospheric Aerosol Particles  

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

Composition and Reactions of Atmospheric Aerosol Particles Print Composition and Reactions of Atmospheric Aerosol Particles Print Microscopic aerosol particles in the atmosphere contain carbonaceous components from mineral dust and combustion emissions released from around the world. How long these tiny particles remain in the atmosphere can have a huge impact on the global climate. Measurements based on high-resolution scanning transmission x-ray images obtained at the ALS have revealed chemical reactions on and in atmospheric aerosol particles that caused particle growth while changing organic composition by 13 to 24% per day, an oxidation rate significantly slower than is currently used in atmospheric models. Since oxidation has a strong effect on particle lifetime in the atmosphere, these results will help climate scientists refine the computer models used to predict climate change.

413

Composition and Reactions of Atmospheric Aerosol Particles  

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

Composition and Reactions of Atmospheric Aerosol Particles Print Composition and Reactions of Atmospheric Aerosol Particles Print Microscopic aerosol particles in the atmosphere contain carbonaceous components from mineral dust and combustion emissions released from around the world. How long these tiny particles remain in the atmosphere can have a huge impact on the global climate. Measurements based on high-resolution scanning transmission x-ray images obtained at the ALS have revealed chemical reactions on and in atmospheric aerosol particles that caused particle growth while changing organic composition by 13 to 24% per day, an oxidation rate significantly slower than is currently used in atmospheric models. Since oxidation has a strong effect on particle lifetime in the atmosphere, these results will help climate scientists refine the computer models used to predict climate change.

414

One-Dimensional Modeling on the Asymmetric Features of a Radio-Frequency Atmospheric Helium Glow Discharge Produced Using a Co-Axial-Type Plasma Generator  

Science Journals Connector (OSTI)

As one type of the atmospheric glow discharges, the radio-frequency atmospheric-pressure glow discharges produced using the water-cooled bare-metallic electrode, which are the...1–3...]. The capacitively-coupled ...

Zhi-Bin Wang; Pei-Si Le; Nan Ge; Qiu-Yue Nie…

2012-08-01T23:59:59.000Z

415

Effect of a non-thermal, atmospheric-pressure, plasma brush on conversion of model self-etch adhesive formulations compared to conventional photo-polymerization  

Science Journals Connector (OSTI)

Objective To determine the effectiveness and efficiency of non-thermal, atmospheric plasmas for inducing polymerization of model dental self-etch adhesives. Methods The monomer mixtures used were bis-[2-(methacryloyloxy)ethyl] phosphate (2MP) and 2-hydroxyethyl methacrylate (HEMA), with mass ratios of 70/30, 50/50 and 30/70. Water was added to the above formulations: 10–30 wt%. These monomer/water mixtures were treated steadily for 40 s under a non-thermal atmospheric plasma brush working at temperatures from 32 to 35 °C. For comparison, photo-initiators were added to the above formulations for photo-polymerization studies, which were light-cured for 40 s. The degree of conversion (DC) of both the plasma- and light-cured samples was measured using FTIR spectroscopy with an attenuated total reflectance attachment. Results The non-thermal plasma brush was effective in inducing polymerization of the model self-etch adhesives. The presence of water did not negatively affect the DC of plasma-cured samples. Indeed, DC values slightly increased, with increasing water content in adhesives: from 58.3% to 68.7% when the water content increased from 10% to 30% in the adhesives with a 50/50 (2MP/HEMA) mass ratio. Conversion values of the plasma-cured groups were higher than those of light-cured samples with the same mass ratio and water content. Spectral differences between the plasma- and light-cured groups indicate subtle structural distinctions in the resultant polymer networks. Significance This research if the first to demonstrate that the non-thermal plasma brush induces polymerization of model adhesives under clinical settings by direct/indirect energy transfer. This device shows promise for polymerization of dental composite restorations having enhanced properties and performance.

Mingsheng Chen; Ying Zhang; Xiaomei Yao; Hao Li; Qingsong Yu; Yong Wang

2012-01-01T23:59:59.000Z

416

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

417

Transient response of the Hadley Centre coupled ocean-atmosphere model to increasing carbon dioxide. Part II: Spatial and temporal structure of response  

SciTech Connect

A high-resolution (2.75{degrees} lat x 3.75{degrees} long) coupled ocean-atmosphere model has been used to simulate the transient response of climate to a gradual increase in atmospheric carbon dioxide concentrations. Although the radiative forcing increases linearly, there is a delay of about 30 yr before the ocean warms appreciably. This {open_quotes}cold start{close_quotes} is, at least partly, an artifact of the experimental design. At the time of doubling (after 70 yr), the patterns of change are similar to those found in comparable studies of the equilibrium response, except in the high latitudes of the Southern Ocean and the North Atlantic, where the warming is considerably reduced. The mechanisms leading to this reduction are discussed. After two to three decades, the pattern of warming is well established. The warming over land is substantially larger than that over the sea, with a consequent lowering of surface pressure over the northern continents in summer. The patterns of changes in precipitation and soil moisture take longer to establish themselves, although locally there are consistent changes after the third decade. 55 refs., 30 figs., 6 tabs.

Murphy, J.M.; Mitchell, J.F.B. [Hadley Centre for Climate Prediction and Research, Berkshire (United Kingdom)] [Hadley Centre for Climate Prediction and Research, Berkshire (United Kingdom)

1995-01-01T23:59:59.000Z

418

Earth and Atmospheric Sciences | More Science | ORNL  

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

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

419

Response of global soil consumption of atmospheric methane to changes in atmospheric climate and nitrogen deposition  

E-Print Network (OSTI)

Response of global soil consumption of atmospheric methane to changes in atmospheric climate June 2013. [1] Soil consumption of atmospheric methane plays an important secondary role in regulating). Here we used a process-based biogeochemistry model to quantify soil consumption during the 20th and 21

420

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

Note: This page contains sample records for the topic "atmospheric mesoscale model" 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

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

422

Section 6. Deep Time: Modelling of Atmospheric CO2 and the Marine CO2-Carbonic Acid-Carbonate System  

Science Journals Connector (OSTI)

...original MAGic model (Arvidson et al., 2006) as revised in Arvidson et al. (2011). There are a number of Earth system models in the literature (e.g., Berner and Canfield 1989; Hansen and Wallmann, 2003; Berner 2004; Bergman et al...

Fred T. Mackenzie; Andreas J. Andersson

423

Overview of the National Atmospheric Release Advisory Center's urban research and development activities  

SciTech Connect

This presentation describes the tools and services provided by the National Atmospheric Release Advisory Center (NARAC) at Lawrence Livermore National Laboratory (LLNL) for modeling the impacts of airborne hazardous materials. NARAC provides atmospheric plume modeling tools and services for chemical, biological, radiological, and nuclear airborne hazards. NARAC can simulate downwind effects from a variety of scenarios, including fires, industrial and transportation accidents, radiation dispersal device explosions, hazardous material spills, sprayers, nuclear power plant accidents, and nuclear detonations. NARAC collaborates on radiological dispersion source terms and effects models with Sandia National Laboratories and the U.S. Nuclear Regulatory Commission. NARAC was designated the interim provider of capabilities for the Department of Homeland Security's Interagency Modeling and Atmospheric Assessment Center by the Homeland Security Council in April 2004. The NARAC suite of software tools include simple stand-alone, local-scale plume modeling tools for end-user's computers, and Web- and Internet-based software to access advanced modeling tools and expert analyses from the national center at LLNL. Initial automated, 3-D predictions of plume exposure limits and protective action guidelines for emergency responders and managers are available from the center in 5-10 minutes. These can be followed immediately by quality-assured, refined analyses by 24 x 7 on-duty or on-call NARAC staff. NARAC continues to refine calculations using updated on-scene information, including measurements, until all airborne releases have stopped and the hazardous threats are mapped and impacts assessed. Model predictions include the 3-D spatial and time-varying effects of weather, land use, and terrain, on scales from the local to regional to global. Real-time meteorological data and forecasts are provided by redundant communications links to the U.S. National Oceanic and Atmospheric Administration (NOAA), U.S. Navy, and U.S. Air Force, as well as an in-house mesoscale numerical weather prediction model. NARAC provides an easy-to-use Geographical Information System (GIS) for display of plume predictions with affected population counts and detailed maps, and the ability to export plume predictions to other standard GIS capabilities. Data collection and product distribution is provided through a variety of communication methods, including dial-up, satellite, and wired and wireless networks. Ongoing research and development activities will be highlighted. The NARAC scientific support team is developing urban parameterizations for use in a regional dispersion model (see companion paper by Delle Monache). Modifications to the numerical weather prediction model WRF to account for characteristics of urban dynamics are also in progress, as is boundary-layer turbulence model development for simulations with resolutions greater than 1km. The NARAC building-resolving computational fluid dynamics capability, FEM3MP, enjoys ongoing development activities such as the expansion of its ability to model releases of dense gases. Other research activities include sensor-data fusion, such as the reconstruction of unknown source terms from sparse and disparate observations.

Lundquist, J K; Sugiyama, G A; Nasstrom, J

2007-09-05T23:59:59.000Z

424

Atmosphere-Surface Exchange Measurements  

Science Journals Connector (OSTI)

...HICKS, B.B., A SIMULATION OF THE EDDY ACCUMULATION...CLOSURES IN 2ND-ORDER MODELING, JOURNAL OF THE ATMOSPHERIC...Their advantag-es are rapid response, linear output...the measurement and modeling of surface fluxes are...the appli-cation of automated conditional sampling...

W. F. Dabberdt; D. H. Lenschow; T. W. Horst; P. R. Zimmerman; S. P. Oncley; A. C. Delany

1993-06-04T23:59:59.000Z

425

Response of a coupled ocean-ice-atmosphere model to data assimilation in the tropical zone of the Pacific Ocean  

Science Journals Connector (OSTI)

This paper deals with numerical experiments based on the coupled ECHAM-HOPE model. The results of experiments are analyzed. The initial fields for the calculations over time periods from one month to one year ...

K. P. Belyaev; N. P. Tuchkova; U. Cubash

2010-06-01T23:59:59.000Z

426

A process for evaluation and state approval of an emergency response atmospheric dispersion model for Rocky Flats, Colorado  

SciTech Connect

This document contains copies of the vugraphs used by C. R. Hodgin for the November 6, 1991 presentation summarizing the process to be used for evaluation of the Emergency Response Dispersion Model. (MHB)

Hodgin, C.R.

1991-11-06T23:59:59.000Z

427

Sensitivity of tropical deep convection in global models: effects of horizontal resolution, surface constraints and 3D atmospheric nudging  

E-Print Network (OSTI)

, the Eastern Indian Ocean and Maritime Continent, and 174 tropical South America. The Inter Tropical Convergence Zone (ITCZ), and to a smaller extent the 175 South Pacific Convergence Zone (SPCZ), also have their signatures in the OLR and PR fields. When 176... larger for PR. This is 161 in agreement with previous studies, which show large model precipitation biases in tropical ocean 162 regions (Martin et al., 2010; Schiemann et al., 2014). For OLR ~85% of model configurations are in 163 good agreement...

Chemel, Charles; Russo, Maria; Hosking, Scott; Telford, Paul; Pyle, John

2014-01-01T23:59:59.000Z

428

Numerical Simulation of the Meso-? Scale Structure and Evolution of the 1977 Johnstown Flood. Part I: Model Description and Verification  

Science Journals Connector (OSTI)

The Pennsylvania State University/NCAR mesoscale model, originally developed by Anthes and Warner, is modified to simulate the meso-? scale structure and evolution of convectively driven weather systems. The modifications include: (i) two-way ...

Da-Lin Zhang; J. Michael Fritsch

1986-09-01T23:59:59.000Z

429

The characterization of ice hydrometeor gamma size distributions as volumes in N0-?–? phase space: Implications for microphysical process modeling  

Science Journals Connector (OSTI)

Gamma distributions represent particle size distributions (SDs) in mesoscale and cloud resolving models that predict one, two or three moments of hydrometeor species. They are characterized by intercept (N0), slope (?) and shape (?) parameters ...

Greg M. McFarquhar; Tsung-Lin Hsieh; Matt Freer; Jeana Mascio; Brian F. Jewett

430

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

431

Four-Dimensional Assimilation of Multitime Wind Profiles over a Single Station and Numerical Simulation of a Mesoscale Convective  

E-Print Network (OSTI)

on the numerical simulation of the convective initiation and evolution. Besides the wind fields, the structureFour-Dimensional Assimilation of Multitime Wind Profiles over a Single Station and Numerical Simulation of a Mesoscale Convective System Observed during IHOP_2002 LEI ZHANG AND ZHAOXIA PU Department

Pu, Zhaoxia

432

The Surface Expression of Semidiurnal Internal Tides near a Strong Source at Hawaii. Part II: Interactions with Mesoscale Currents*  

E-Print Network (OSTI)

: the cyclone causes the energy of internal tide rays propagating through its core to increase near the surface with astronomical forcing because of the presence of mesoscale variability. Internal tide energy is mainly affected but not negligible role, inducing energy transfers between the internal tides and background currents. Furthermore

433

Mesoscale Self-Assembly: Capillary Bonds and Negative Menisci Ned Bowden, Scott R. J. Oliver, and George M. Whitesides*  

E-Print Network (OSTI)

Mesoscale Self-Assembly: Capillary Bonds and Negative Menisci Ned Bowden, Scott R. J. Oliver., Cambridge, Massachusetts 02138 ReceiVed: September 2, 1999 This paper describes the self-assembly) that examined the self-assembly of hexagonal plates of PDMS (F ) 1.05 g/cm3) that had a density close

Prentiss, Mara

434

October 1986 R. H. Johnson 721 Lower-Tropospheric Warming and Drying in Tropical Mesoscale Convective Systems  

E-Print Network (OSTI)

October 1986 R. H. Johnson 721 Lower-Tropospheric Warming and Drying in Tropical Mesoscale Convective Systems: Implications for the Problem of Cumulus Parameterization By Richard H. Johnson Department beneath the stratiform com- ponents of these systems (Houze, 1977; Zipser, 1977; Johnson and Kriete, 1982

Johnson, Richard H.

435

Modeling of the Cryogenic Liquid Pool Evaporation and the Effect of the Convective Heat Transfer from Atmosphere  

E-Print Network (OSTI)

of this activity. This includes the prediction of the consequences of potential loss of containment of LNG, which requires the modelling of the vaporization rate of LNG resulting from the heat transfer between the pool and surroundings. The present work focuses...

Nawaz, Waqas

2014-04-25T23:59:59.000Z

436

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

437

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

SciTech Connect

A new heterogeneous ice nucleation parameterization that covers a wide temperature range (-36 ?C to -78 ?C) is presented. Developing and testing such an ice nucleation parameterization, which is constrained through identical experimental conditions, is critical in order to accurately simulate the ice nucleation processes in cirrus clouds. The surface-scaled ice nucleation efficiencies of hematite particles, inferred by ns, were derived from AIDA (Aerosol Interaction and Dynamics in the Atmosphere) cloud chamber measurements under water subsaturated conditions that were realized by continuously changing temperature (T) and relative humidity with respect to ice (RHice) in the chamber. Our measurements showed several different pathways to nucleate ice depending on T and RHice conditions. For instance, almost independent freezing was observed at -60 ?C < T < -50 ?C, where RHice explicitly controlled ice nucleation efficiency, while both T and RHice played roles in other two T regimes: -78 ?C < T < -60 ?C and -50 ?C < T < -36 ?C. More specifically, observations at T colder than -60 ?C revealed that higher RHice was necessary to maintain constant ns, whereas T may have played a significant role in ice nucleation at T warmer than -50 ?C. We implemented new ns parameterizations into two cloud models to investigate its sensitivity and compare with the existing ice nucleation schemes towards simulating cirrus cloud properties. Our results show that the new AIDA-based parameterizations lead to an order of magnitude higher ice crystal concentrations and inhibition of homogeneous nucleation in colder temperature regions. Our cloud simulation results suggest that atmospheric dust particles that form ice nuclei at lower temperatures, below -36 ?C, can potentially have stronger influence on cloud properties such as cloud longevity and initiation when compared to previous parameterizations.

Hiranuma, Naruki; Paukert, Marco; Steinke, Isabelle; Zhang, Kai; Kulkarni, Gourihar R.; Hoose, Corinna; Schnaiter, Martin; Saathoff, Harald; Mohler, Ottmar

2014-12-10T23:59:59.000Z

438

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

SciTech Connect

The response of the Los Alamos atmospheric general circulation model to the smoke from the Kuwaiti oil fires set in 1991 is examined. The model has an interactive soot transport module that uses a Lagrangian tracer particle scheme. The statistical significance of the results is evaluated using a methodology based on the classic Student`s t test. Among various estimated smoke emission rates and associated visible absorption coefficients, the worst- and best-case scenarios are selected. In each of the scenarios, an ensemble of 10, 30-day June simulations are conducted with the smoke, and are compared to the same 10 June simulations without the smoke. The results of the worst-case scenario show that a statistically significant wave train pattern propagates eastward-poleward downstream from the source. The signals favorably compare with the observed climate anomalies in summer 1991, albeit some possible El Nino-Southern Oscillation effects were involved in the actual climate. The results of the best-case (i.e., least-impact) scenario show that the significance is rather small but that its general pattern is quite similar to that in the worst-case scenario. 24 refs., 5 figs.

Chih-Yue Jim Kao; Glatzmaier, G.A.; Malone, R.C. [Los Alamos National Lab., NM (United States)

1994-07-20T23:59:59.000Z

439

Review of Wind Energy Forecasting Methods for Modeling Ramping Events  

SciTech Connect

Tall onshore wind turbines, with hub heights between 80 m and 100 m, can extract large amounts of energy from the atmosphere since they generally encounter higher wind speeds, but they face challenges given the complexity of boundary layer flows. This complexity of the lowest layers of the atmosphere, where wind turbines reside, has made conventional modeling efforts less than ideal. To meet the nation's goal of increasing wind power into the U.S. electrical grid, the accuracy of wind power forecasts must be improved. In this report, the Lawrence Livermore National Laboratory, in collaboration with the University of Colorado at Boulder, University of California at Berkeley, and Colorado School of Mines, evaluates innovative approaches to forecasting sudden changes in wind speed or 'ramping events' at an onshore, multimegawatt wind farm. The forecast simulations are compared to observations of wind speed and direction from tall meteorological towers and a remote-sensing Sound Detection and Ranging (SODAR) instrument. Ramping events, i.e., sudden increases or decreases in wind speed and hence, power generated by a turbine, are especially problematic for wind farm operators. Sudden changes in wind speed or direction can lead to large power generation differences across a wind farm and are very difficult to predict with current forecasting tools. Here, we quantify the ability of three models, mesoscale WRF, WRF-LES, and PF.WRF, which vary in sophistication and required user expertise, to predict three ramping events at a North American wind farm.

Wharton, S; Lundquist, J K; Marjanovic, N; Williams, J L; Rhodes, M; Chow, T K; Maxwell, R

2011-03-28T23:59:59.000Z

440

Simulation of Atmospheric Pressure Non-Thermal Plasma Discharges for Surface Decontamination Applications  

Science Journals Connector (OSTI)

Numerical simulations are conducted to characterize atmospheric pressure plasma discharges for surface decontamination applications. A self ... dimensional hybrid model is developed to simulate the atmospheric pr...

T. Farouk; B. Farouk; A. Gutsol; A. Fridman

2008-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "atmospheric mesoscale model" 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

3.021J / 1.021J / 10.333J / 18.361J / 22.00J Introduction to Modeling and Simulation, Spring 2008  

E-Print Network (OSTI)

This course explores the basic concepts of computer modeling and simulation in science and engineering. We'll use techniques and software for simulation, data analysis and visualization. Continuum, mesoscale, atomistic and ...

Buehler, Markus

442

Hadley Cell Dynamics in a Virtually Dry Snowball Earth Atmosphere  

Science Journals Connector (OSTI)

The Hadley cell of a virtually dry snowball Earth atmosphere under equinox insolation is studied in a comprehensive atmospheric general circulation model. In contrast to the Hadley cell of modern Earth, momentum transport by dry convection, which ...

Aiko Voigt; Isaac M. Held; Jochem Marotzke

2012-01-01T23:59:59.000Z

443

Diffractive imaging at large Fresnel number: Challenge of dynamic mesoscale imaging with hard x rays  

Science Journals Connector (OSTI)

Real materials have structure at both the atomic or crystalline scale as well as at interfaces and defects at the larger scale of grains. There is a need for the study of materials at the “mesoscale,” the scale at which subgranular physical processes and intergranular organization couple to determine microstructure, crucially impacting constitutive response at the engineering macroscale. Diffractive imaging using photons that can penetrate multiple grains of material would be a transformative technique for the study of the performance of materials in dynamic extremes. Thicker samples imply higher energy photons of shorter wavelength, and imaging of multiple grains implies bigger spot sizes. Such imaging requires the use of future planned and proposed hard x-ray free electron lasers (such as the European XFEL) to provide both the spatial coherence transverse to the large spots and the peak brilliance to provide the short illumination times. The result is that the Fresnel number of the system becomes large and is no longer in the Fraunhofer far-field limit. The interrelated issues of diffractive imaging at large Fresnel number are analyzed, including proof that diffractive imaging is possible in this limit and estimates of the signal-to-noise possible. In addition, derivation of the heating rates for brilliant pulses of x rays are presented. The potential and limitations on multiple dynamic images are derived. This paper will present a study of x-ray interactions with materials in this new regime of spatially coherent but relatively large mesoscale spots at very hard energies. It should provide the theory and design background for the experiments and facilities required to control materials in extreme environments, in particular for the next generation of very-hard-x-ray free electron lasers.

John L. Barber; Cris W. Barnes; Richard L. Sandberg; Richard L. Sheffield

2014-05-12T23:59:59.000Z

444

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

445

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

446

A Global Climatology of Albedo, Roughness Length and Stomatal Resistance for Atmospheric General Circulation Models as Represented by the Simple Biosphere Model (SiB)  

Science Journals Connector (OSTI)

Components of the Simple Biosphere Model (SiB) of Sellers et al. were used to generate global monthly fields of surface albedo (0.4–4.0 ?m), roughness length and minimum surface (stomatal) resistance.

J. L. Dorman; P. J. Sellers

1989-09-01T23:59:59.000Z

447

Atmospheric Transport of Radionuclides  

SciTech Connect

The purpose of atmospheric transport and diffusion calculations is to provide estimates of concentration and surface deposition from routine and accidental releases of pollutants to the atmosphere. This paper discusses this topic.

Crawford, T.V.

2003-03-03T23:59:59.000Z

448

The Boulder Atmospheric Observatory  

Science Journals Connector (OSTI)

The Boulder Atmospheric Observatory (BAO) is a unique research facility for studying the planetary boundary layer and for testing and calibrating atmospheric sensors. The facility includes a 300 m tower instrumented with fast- and slow-response ...

J. C. Kaimal; J. E. Gaynor

1983-05-01T23:59:59.000Z

449

Representing El Niño in Coupled Ocean–Atmosphere GCMs: The Dominant Role of the Atmospheric Component  

Science Journals Connector (OSTI)

A systematic modular approach to investigate the respective roles of the ocean and atmosphere in setting El Niño characteristics in coupled general circulation models is presented. Several state-of-the-art coupled models sharing either the same ...

E. Guilyardi; S. Gualdi; J. Slingo; A. Navarra; P. Delecluse; J. Cole; G. Madec; M. Roberts; M. Latif; L. Terray

2004-12-01T23:59:59.000Z

450

8, 10691088, 2008 Atmospheric  

E-Print Network (OSTI)

into the atmosphere (Molina et al., 1974; Farman et al., 1985) has led to an interna- tional effort to replace

Boyer, Edmond

451

The Upper Atmosphere Observatory  

Science Journals Connector (OSTI)

...with *the plasma frethe progress...explorcreated an even larger number of...the upper atmosphere and ionosphere...the upper atmosphere. For this...ionospheric plasma motion simul-taneously...field is large, the horizontal...resolved. The atmospheric gravity waves...simul-taneously at a large number of...two regions plasma drifts separated...

J. V. Evans

1972-05-05T23:59:59.000Z

452

The Upper Atmosphere Observatory  

Science Journals Connector (OSTI)

...DATA, JOURNAL OF ATMOSPHERIC AND TERRESTRIAL...IN NEAR-EARTH PLASMA, SPACE SCIENCE...INVESTIGATION OF WHISTLING ATMOSPHERICS, PHILOSOPHICAL...TRANSPOLAR EXOSPHERIC PLASMA .1. PLASMASPHERE...dynamics of the upper atmosphere. For this purpose...the ionospheric plasma motion simul-taneously...

J. V. Evans

1972-05-05T23:59:59.000Z

453

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

454

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

Science Journals Connector (OSTI)

Changes in atmospheric CO2 variability during the twenty-first century may provide insight about ecosystem responses to climate change and have implications for the design of carbon monitoring programs. This paper describes changes in the three-...

Gretchen Keppel-Aleks; James T. Randerson; Keith Lindsay; Britton B. Stephens; J. Keith Moore; Scott C. Doney; Peter E. Thornton; Natalie M. Mahowald; Forrest M. Hoffman; Colm Sweeney; Pieter P. Tans; Paul O. Wennberg; Steven C. Wofsy

2013-07-01T23:59:59.000Z

455

Probabilistic Evaluation of the Dynamics and Predictability of the Mesoscale Convective Vortex of 1013 June 2003  

E-Print Network (OSTI)

National Center for Atmospheric Research,* Boulder, Colorado (Manuscript received 14 September 2005 have been linked to extreme rainfall events, such as the Johnstown, Pennsylvania, flood of 1977 (Bosart

Meng, Zhiyong

456

Faster Decomposition Under Increased Atmospheric CO2 Limits Soil Carbon Storage  

Science Journals Connector (OSTI)

...atmosphere is a major focus of Earth system models, because the C cycle is sensitive...cycle affect our climate. Earth system models project that rising atmospheric...through microbial decomposition. Earth system models typically treat decomposition...

Kees Jan van Groenigen; Xuan Qi; Craig W. Osenberg; Yiqi Luo; Bruce A. Hungate

2014-05-02T23:59:59.000Z

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

Numerical Analysis of Flow Characteristics of An Atmospheric Plasma Torch  

E-Print Network (OSTI)

Numerical Analysis of Flow Characteristics of An Atmospheric Plasma Torch You-Jae Kim, J.-G. HanCheon-dong, Suwon 440-746, KOREA Abstract The atmospheric plasma is regarded as an effective method for surface mathematical models used for simulating plasma characteristics inside an atmospheric plasma torch is carried

Paris-Sud XI, Université de

459

Using Mesoscale Simulations to Train Statistical Models of Tropical Cyclone Intensity over Land  

Science Journals Connector (OSTI)

The decay of tropical cyclones after landfall is a key factor in estimating the extent of the hazard overland. Yet our current understanding of this decay is challenged by the low frequency of past events. Consequently, one cannot rely solely ...

Augustin Colette; Nadja Leith; Vincent Daniel; Enrica Bellone; David S. Nolan

2010-06-01T23:59:59.000Z

460

Mesoscale Modeling of a Li-Ion Polymer Cell Chia-Wei Wanga,  

E-Print Network (OSTI)

version 3.2 . Four types of cathode active material particles, arranged in both regular and random arrays sizes of active material particles were also shown to be beneficial for high power density applications and for low diffusivity active materials. © 2007 The Electrochemical Society. DOI: 10.1149/1.2778285 All

Sastry, Ann Marie

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


461

Study and implementation of mesoscale weather forecasting models in the wind industry.  

E-Print Network (OSTI)

?? As the wind industry is developing, it is asking for more reliable short-term wind forecasts to better manage the wind farms’ operations and electricity… (more)

Jourdier, Bénédicte

2012-01-01T23:59:59.000Z

462

Mesoscale environmental models accompanying convection in the Texas HIPLEX region / by Mark Edward Humbert  

E-Print Network (OSTI)

. The basic data were gridded using a scheme developed by Barnes(1964). The averages determined in this manner are an adequate representation of con- ditions surrounding Big Spring. The variables are presented at 850, 700, and 500 mb s1nce these levels... not be established at Big Spring since the moisture data were missing for that hour. 23-24 June 1977 Charts of radar echoes for this day are presented in Fig. 25 with those charts in the left-hand column corresponding to sounding times. Moderate rainshowers...

Humbert, Mark Edward

2012-06-07T23:59:59.000Z

463

Assessing Seasonal Transport and Deposition of Agricultural Emissions in Eastern North Carolina, U.S.A.  

E-Print Network (OSTI)

the variability and uncertainty in the regional pollutant transport. Key words: Air pollution, atmospheric values obtained using an air pollution transport and dispersion model. This mesoscale information Carolina. Results show that highly variable seasonal and diurnal atmospheric circulations characterize

Raman, Sethu

464

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

465

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

SciTech Connect

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

466

Equilibrium Structure of a Triblock Copolymer System Revealed by Mesoscale Simulation and Neutron Scattering  

SciTech Connect

We have performed both mesoscale simulations and neutron scattering experiments on Pluronic L62, a poly(ethylene oxide)-poly(propylene oxide)-poly(ethylene oxide) (PEO-PPO-PEO) triblock copolymer system in aqueous solution. The influence of simulation variables such PEO/PPO block ratio, interaction parameters, and coarse-graining methods is extensively investigated by covering all permutations of parameters found in the literatures. Upon increasing the polymer weight fraction from 50 wt% to 90 wt%, the equilibrium structure of the isotropic, reverse micellar, bicontinuous, worm-like micelle network, and lamellar phases are respectively predicted from the simulation depending on the choices of simulation parameters. Small angle neutron scattering (SANS) measurements show that the same polymer systems exhibit the spherical micellar, lamellar, and reverse micellar phases with the increase of the copolymer concentration at room temperature. Detailed structural analysis and comparison with simulations suggest that one of the simulation parameter sets can provide reasonable agreement with the experimentally observed structures.

Do, Changwoo [ORNL] [ORNL; Chen, Wei-Ren [ORNL] [ORNL; Hong, Kunlun [ORNL] [ORNL; Smith, Gregory Scott [ORNL] [ORNL

2013-01-01T23:59:59.000Z

467

Impact of mesoscale eddies on water transport between the Pacific Ocean and the Bering Sea  

E-Print Network (OSTI)

Sea surface height anomalies observed by satellites in 1993--2012 are combined with simulation and observations by surface drifters and Argo floats to study water flow pattern in the Near Strait (NS) connected the Pacific Ocean with the Bering Sea. Daily Lagrangian latitudinal maps, computed with the AVISO surface velocity field, and calculation of the transport across the strait show that the flow through the NS is highly variable and controlled by mesoscale and submesoscale eddies in the area. On the seasonal scale, the flux through the western part of the NR is negatively correlated with the flux through its eastern part ($r=-0.93$). On the interannual time scale, a significant positive correlation ($r=0.72$) is diagnosed between the NS transport and the wind stress in winter. Increased southward component of the wind stress decreases the northward water transport through the strait. Positive wind stress curl over the strait area in winter--spring generates the cyclonic circulation and thereby enhances the...

Prants, S V; Budyansky, M V; Uleysky, M Yu

2013-01-01T23:59:59.000Z

468

Atmospheric Radiation Measurement Program  

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

3 3 ARM 2003 Tom Ackerman Chief Scientist Tom Ackerman Chief Scientist ARM ARM Atmospheric Radiation Measurement Atmospheric Radiation Measurement WARNING! WARNING! Today is April 1 But that has NO bearing on this message Today is April 1 But that has NO bearing on this message ARM ARM Atmospheric Radiation Measurement Atmospheric Radiation Measurement Two Topics Two Topics * Status of ARM (quick overview) * Science plan - ARM in the next 5 years * Status of ARM (quick overview) * Science plan - ARM in the next 5 years ARM ARM Atmospheric Radiation Measurement Atmospheric Radiation Measurement ARM Status - Science ARM Status - Science * Steadily increasing productivity - Poster session - over 220 posters (may need to do something about submissions next year) - Peer-reviewed articles: 2.5 to 3 per year per

469

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

E-Print Network (OSTI)

and Climate Model Intercomparison Project (ACCMIP): overviewand Biogeosciences Climate Model Intercomparison Project (and Climate Model Intercompari- son Project (ACCMIP), Atmos.

2013-01-01T23:59:59.000Z

470

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

471

ARM - Atmospheric Heat Budget  

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

ListAtmospheric Heat Budget Outreach Home Room News Publications Traditional Knowledge Kiosks Barrow, Alaska Tropical Western Pacific Site Tours Contacts Students Study Hall About...

472

Photochemistry in Terrestrial Exoplanet Atmospheres III: Photochemistry and Thermochemistry in Thick Atmospheres on Super Earths and Mini Neptunes  

E-Print Network (OSTI)

Some super Earths and mini Neptunes will likely have thick atmospheres that are not H2-dominated. We have developed a photochemistry-thermochemistry kinetic-transport model for exploring the compositions of thick atmospheres on super Earths and mini Neptunes, applicable for both H2-dominated atmospheres and non-H2-dominated atmospheres. Using this model to study thick atmospheres for wide ranges of temperatures and elemental abundances, we classify them into hydrogen-rich atmospheres, water-rich atmospheres, oxygen-rich atmospheres, and hydrocarbon-rich atmospheres. We find that carbon has to be in the form of CO2 rather than CH4 or CO in a H2-depleted water-dominated thick atmosphere, and that the preferred loss of light elements from an oxygen-poor carbon-rich atmosphere leads to formation of unsaturated hydrocarbons (C2H2 and C2H4). We apply our self-consistent atmosphere models to compute spectra and diagnostic features for known transiting low-mass exoplanets GJ 1214 b, HD 97658 b, and 55 Cnc e. For GJ 1...

Hu, Renyu

2014-01-01T23:59:59.000Z

473

Incorporation of 3D Shortwave Radiative Effects within the Weather Research and Forecasting Model  

SciTech Connect

A principal goal of the Atmospheric Radiation Measurement (ARM) Program is to understand the 3D cloud-radiation problem from scales ranging from the local to the size of global climate model (GCM) grid squares. For climate models using typical cloud overlap schemes, 3D radiative effects are minimal for all but the most complicated cloud fields. However, with the introduction of ''superparameterization'' methods, where sub-grid cloud processes are accounted for by embedding high resolution 2D cloud system resolving models within a GCM grid cell, the impact of 3D radiative effects on the local scale becomes increasingly relevant (Randall et al. 2003). In a recent study, we examined this issue by comparing the heating rates produced from a 3D and 1D shortwave radiative transfer model for a variety of radar derived cloud fields (O'Hirok and Gautier 2005). As demonstrated in Figure 1, the heating rate differences for a large convective field can be significant where 3D effects produce areas o f intense local heating. This finding, however, does not address the more important question of whether 3D radiative effects can alter the dynamics and structure of a cloud field. To investigate that issue we have incorporated a 3D radiative transfer algorithm into the Weather Research and Forecasting (WRF) model. Here, we present very preliminary findings of a comparison between cloud fields generated from a high resolution non-hydrostatic mesoscale numerical weather model using 1D and 3D radiative transfer codes.

O'Hirok, W.; Ricchiazzi, P.; Gautier, C.

2005-03-18T23:59:59.000Z

474

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

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

475

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

476

A New Method to Produce Sea Surface Temperature Using Satellite Data Assimilation into an AtmosphereOcean Mixed Layer Coupled Model  

E-Print Network (OSTI)

A New Method to Produce Sea Surface Temperature Using Satellite Data Assimilation method of producing sea surface temperature (SST) data for numerical weather prediction is sug- gested, which is obtained from the assimilation of satellite-derived SST into an atmosphere­ocean mixed layer

Noh, Yign

477

Observational Analysis of the Predictability of Mesoscale Convective Systems ISRAEL L. JIRAK AND WILLIAM R. COTTON  

E-Print Network (OSTI)

AND WILLIAM R. COTTON Department of Atmospheric Science, Colorado State University, Fort Collins, Colorado merge into a large, long-lived organized convective system (Cotton and Anthes 1989). Thus, forecasting

478

Conference on Atmospheric Pollution  

Science Journals Connector (OSTI)

... THE half-yearly Conference of representatives of local authorities and other organisations co-operating with the Department of Scientific ... of atmospheric pollution was held in the offices of the Department on May 25. The Conference received from Dr. G. M. B. Dobson, chairman of the Atmospheric Pollution ...

1936-05-30T23:59:59.000Z

479

Atmospheric Science and Climate Research [EVS Program Area]  

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

Atmospheric Science and Climate Research Atmospheric Science and Climate Research EVS research, combined with portable, high-performance climate and weather applications, offers a unique look at the complexities of a dynamic planet. In an ever-changing, dynamic climate, we measure, model, and analyze atmospheric processes that are vital to understanding our planet. Our measurement capabilities range from remote sensing and surface meteorology instruments to instrumentation designed to quantify the land-atmosphere exchange of energy, water, and greenhouse gases. Modeling capabilities begin with regional-scale climate, air quality, and aerosol modeling and extend to global chemical transport models, general circulation models of the atmosphere, models of the biosphere, and coupled Earth system models.

480

E-Print Network 3.0 - atmospheric layers Sample Search Results  

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

layer model Summary: an atmosphere, using the layer model, which incorporates the greenhouse effect of the atmosphere. For now... ,atm + Idown,atm Iup, ground If radiation up and...

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


481

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)

in the Community Earth System Model: Evaluation andpredictions from CMIP5 Earth system models and comparisonusing the Community Earth System Model–Biogeochemistry (

2013-01-01T23:59:59.000Z

482

On the effect of the steady-state approximation in time-space composite studies of mesoscale convective systems  

E-Print Network (OSTI)

ON THE EFFECT OF THE STRA 'Y-STATE APPROXIMATION IN TIME-SPACE COMPOSITE STUDIES OF MESOSCALE CONVECTIVE SYSTEMS A Thesis KEVIN MORGAN MATTISON Subnitted to the Office of Graduate Studies of Texas A&M University in partial fulfillnent... of the requirements for the degree of MASTER OF SCIENCE Decenber 1992 Major Subject: Meteorology ON THE EFFECT OF THE STEADY-STATE APPROXINATIOH IN TIME-SPACE COMPOSITE STUDIES OF NESOSCALE COHVECTIVE SYSTENS A Thesis KEVIN MORGAN NATTISOH Approved as to style...

Mattison, Kevin Morgan

2012-06-07T23:59:59.000Z

483

Mesoscale Surface Pressure and Temperature Features Associated with Bow Echoes REBECCA D. ADAMS-SELIN AND RICHARD H. JOHNSON  

E-Print Network (OSTI)

-SELIN AND RICHARD H. JOHNSON Department of Atmospheric Science, Colorado State University, Fort Collins, Colorado

Johnson, Richard H.

484

Mitigation of atmospheric carbon emissions through increased energy efficiency versus increased non-carbon energy sources: A trade study using a simplified {open_quotes}market-free{close_quotes} exogenously driven model  

SciTech Connect

A simplified model of global, long-term energy use is described and used to make a `top-level` comparison of two generic approaches for mitigating atmospheric carbon emissions: (a) those based on increased energy efficiency; and (b) those based on increased use of reduced- or non-carbon fuels. As approximate as is the model, first-order estimates of and trade offs between increasing non-carbon generation capacities (e.g., supply-side solutions) versus energy-use efficiency (e.g., demand-side solutions) to stem atmospheric carbon accumulations can be useful in guiding more elaborate models. At the level of this analysis, both the costs of abatement and the costs of damage can be large, with the formation of benefit-to-cost ratios as a means of assessment being limited by uncertainties associated with relating given climatic responses to greenhouse warming to aggregate damage cost, as well as uncertainties associated with procedures used for multi-generation discounting of both abatement and damage costs. In view of uncertainties associated with both supply-side and demand-side approaches, as well as the estimation of greenhouse-warming responses per se, a combination of solutions seems prudent. Key findings are: (a) the relative insensitivity of the benefit-to-cost ratio adopted in this study to supply-side versus demand-side approaches to abating atmospheric carbon-dioxide emissions; (b) the extreme sensitivity of damage costs, abatement costs, and the related benefit-to-cost ratios to the combination of discounting procedure and the (time) concavity of the function used to relate global temperature rise to damage costs; and (c) no matter the discounting procedure and/or functional relationship between average temperature rise and a damage cost, a goal of increased per-capita gross world product at minimum damage suggests action now rather than delay.

Krakowski, R.A.

1997-08-24T23:59:59.000Z

485

Nature: Earth's Atmosphere and Beyond  

Science Journals Connector (OSTI)

Nature: Earth's Atmosphere and Beyond ... The column summarizes research articles from Nature that report on anthropogenic activities and natural phenomena that influence the chemical composition of Earth's atmosphere. ...

Sabine Heinhorst; Gordon Cannon

2003-10-01T23:59:59.000Z