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Sample records for nested mesoscale model

  1. NESTED GRID MESOSCALE ATMOSPHERIC CHEMISTRY MODEL

    EPA Science Inventory

    A nested grid version of the Regional Acid Deposition Model (RADM) has been developed. he horizontal grid interval size of the nested model is 3 times smaller than that of RADM (80/3 km 26.7 km). herefore the nested model is better able to simulate mesoscale atmospheric processes...

  2. A nested-grid mesoscale numerical weather prediction model modified for Space Shuttle operational requirements

    NASA Technical Reports Server (NTRS)

    Kaplan, M. L.; Zack, J. W.; Wong, V. C.; Coats, G. D.

    1983-01-01

    A nested-grid mesoscale atmospheric simulation system (MASS) is tested over Florida for the case of intense seabreeze-induced convection. The goal of this modeling system is to provide real-time aviation weather support which is designed to fit local terminal operations such as those supporting NASA's STS. Results from a 58 km and a 14.5 km nested-grid simulation show that this version of the MASS is capable of simulating many of the basic characteristics of convective complexes during periods of relatively weak synoptic scale flow regimes. However, it is noted that extensive development work is required with nested-grid cumulus and planetary boundary layer parameterization schemes before many of the meso-beta scale features such as thunderstorm downdraft-produced bubble high pressure centers can be accurately simulated. After these schemes are properly tuned, MASS can be utilized to initialize microscale modeling systems.

  3. Implementation of wind turbine parameterizations in a mesoscale-LES nested model framework

    NASA Astrophysics Data System (ADS)

    Chow, Fotini; Marjanovic, Nikola; Mirocha, Jeffrey

    2014-11-01

    Wind turbine performance depends on weather conditions, local topography, and wind turbine spacing, among other factors. Atmospheric simulations can be used to predict wind energy production at increasingly higher resolutions. Turbine models placed within such simulations can be used to investigate turbine operation and performance. This work describes the implementation of generalized actuator disk (GAD) and line (GAL) models into the Weather Research and Forecasting (WRF) mesoscale atmospheric model. WRF can be used in a grid nested configuration starting from the mesoscale (~10 km resolution) and ending with fine scale resolutions (~1-10 m) suitable for large-eddy simulations (LES). At LES scales it becomes possible to resolve both the thrust and torque forces generated on turbines and imparted to the atmosphere using GAD and GAL models. Both models include real-time yaw and pitch control to respond to changing flow conditions. Here, the GAD and GAL are tested for idealized and real model configurations and compared to data from a wind farm. Comparisons are also made that help determine the importance of turbine blade tilt away from the tower and the inclusion of tower and turbine hub drag effects.

  4. Applying different spatial distribution and modelling concepts in three nested mesoscale catchments of Germany

    NASA Astrophysics Data System (ADS)

    Bongartz, K.

    Distributed, physically based river basin models are receiving increasing importance in integrated water resources management (IWRM) in Germany and in Europe, especially after the release of the new European Water Framework Directive (WFD). Applications in mesoscale catchments require an appropriate approach to represent the spatial distribution of related catchment properties such as land use, soil physics and topography by utilizing techniques of remote sensing and GIS analyses. The challenge is to delineate scale independent homogeneous modelling entities which, on the one hand may represent the dynamics of the dominant hydrological processes and, on the other hand can be derived from spatially distributed physiographical catchment properties. This scaling problem is tackled in this regional modelling study by applying the concept of hydrological response units (HRUs). In a nested catchment approach three different modelling conceptualisations are used to describe the runoff processes: (i) the topographic stream-segment-based HRU delineation proposed by Leavesley et al. [Precipitation-Runoff-Modelling-System, User’s Manual, Water Resource Investigations Report 83-4238, US Geological Survey, 1983]; (ii) the process based physiographic HRU-concept introduced by Flügel [Hydrol. Process. 9 (1995) 423] and (iii) an advanced HRU-concept adapted from (ii), which included the topographic topology of HRU-areas and the river network developed by Staudenraush [Eco Regio 8 (2000) 121]. The influence of different boundary conditions associated with changing the landuse classes, the temporal data resolution and the landuse scenarios were investigated. The mesoscale catchment of the river Ilm ( A∼895 km 2) in Thuringia, Germany, and the Precipitation-Runoff-Modelling-System (PRMS) were selected for this study. Simulations show that the physiographic based concept is a reliable method for modelling basin dynamics in catchments up to 200 km 2 whereas in larger catchments

  5. Data assimilation of a ten-day period during June 1993 over the Southern Great Plains Site using a nested mesoscale model

    SciTech Connect

    Dudhia, J.; Guo, Y.R.

    1996-04-01

    A goal of the Atmospheric Radiation Measurement (ARM) Program has been to obtain a complete representation of physical processes on the scale of a general circulation model (GCM) grid box in order to better parameterize radiative processes in these models. Since an observational network of practical size cannot be used alone to characterize the Cloud and Radiation Testbed (CART) site`s 3D structure and time development, data assimilation using the enhanced observations together with a mesoscale model is used to give a full 4D analysis at high resolution. The National Center for Atmospheric Research (NCAR)/Penn State Mesoscale Model (MM5) has been applied over a ten-day continuous period in a triple-nested mode with grid sizes of 60, 20 and 6.67 in. The outer domain covers the United States` 48 contiguous states; the innermost is a 480-km square centered on Lamont, Oklahoma. A simulation has been run with data assimilation using the Mesoscale Analysis and Prediction System (MAPS) 60-km analyses from the Forecast Systems Laboratory (FSL) of the National Ocean and Atmospheric Administration (NOAA). The nested domains take boundary conditions from and feed back continually to their parent meshes (i.e., they are two-way interactive). As reported last year, this provided a simulation of the basic features of mesoscale events over the CART site during the period 16-26 June 1993 when an Intensive Observation Period (IOP) was under way.

  6. Validation of mesoscale models

    NASA Technical Reports Server (NTRS)

    Kuo, Bill; Warner, Tom; Benjamin, Stan; Koch, Steve; Staniforth, Andrew

    1993-01-01

    The topics discussed include the following: verification of cloud prediction from the PSU/NCAR mesoscale model; results form MAPS/NGM verification comparisons and MAPS observation sensitivity tests to ACARS and profiler data; systematic errors and mesoscale verification for a mesoscale model; and the COMPARE Project and the CME.

  7. Acid rain: Mesoscale model

    NASA Technical Reports Server (NTRS)

    Hsu, H. M.

    1980-01-01

    A mesoscale numerical model of the Florida peninsula was formulated and applied to a dry, neutral atmosphere. The prospective use of the STAR-100 computer for the submesoscale model is discussed. The numerical model presented is tested under synoptically undisturbed conditions. Two cases, differing only in the direction of the prevailing geostrophic wind, are examined: a prevailing southwest wind and a prevailing southeast wind, both 6 m/sec at all levels initially.

  8. Mesoscale ocean dynamics modeling

    SciTech Connect

    mHolm, D.; Alber, M.; Bayly, B.; Camassa, R.; Choi, W.; Cockburn, B.; Jones, D.; Lifschitz, A.; Margolin, L.; Marsden, L.; Nadiga, B.; Poje, A.; Smolarkiewicz, P.; Levermore, D.

    1996-05-01

    This is the final report of a three-year, Laboratory-Directed Research and Development (LDRD) project at the Los Alamos National Laboratory (LANL). The ocean is a very complex nonlinear system that exhibits turbulence on essentially all scales, multiple equilibria, and significant intrinsic variability. Modeling the ocean`s dynamics at mesoscales is of fundamental importance for long-time-scale climate predictions. A major goal of this project has been to coordinate, strengthen, and focus the efforts of applied mathematicians, computer scientists, computational physicists and engineers (at LANL and a consortium of Universities) in a joint effort addressing the issues in mesoscale ocean dynamics. The project combines expertise in the core competencies of high performance computing and theory of complex systems in a new way that has great potential for improving ocean models now running on the Connection Machines CM-200 and CM-5 and on the Cray T3D.

  9. Improving mesoscale QPF in regions of complex terrain using a fine-scaled nested model and satellite-retrieved data

    NASA Astrophysics Data System (ADS)

    Kuligowski, Robert Joseph

    2000-10-01

    Quantitative precipitation forecasting (QPF) has importance for a broad variety of applications, from agricultural and construction interests to flood forecasting. Both the accuracy and timeliness of QPF are crucial components in its usefulness, especially for hydrologic forecasting, but in general the present state of QPF is lacking in both areas. This thesis approaches QPF from a numerical weather prediction (NWP) model on two fronts. The first is to present a NWP model for predicting short-term precipitation at very fine scales (1-km) over regions with highly variable terrain, and an example from the Pocono Mountains in Pennsylvania is presented. The second is to improve the performance of the NWP model by using satellite data to estimate the initial fields of temperature and moisture used in the model. This use of satellite data has two steps. The first is to produce retrievals of temperature and moisture at individual points using an artificial neural network (ANN) trained on collocated satellite and radiosonde data. The second step is to us a fractal disaggregation scheme to re-scale the satellite images that are at three different horizontal resolutions to the fine spatial resolution of the NWP model. The results show that the fine-scale NWP model using the satellite- retrieved initial conditions has slightly better skill at predicting precipitation than a comparable model, but that the model variables not replaced with satellite- retrieved values still exert a significant influence on the model solution.

  10. Nesting Large-Eddy Simulations Within Mesoscale Simulations for Wind Energy Applications

    NASA Astrophysics Data System (ADS)

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

    2008-12-01

    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) account for complex terrain and resolve individual atmospheric eddies on length scales smaller than turbine blades. These small-domain high-resolution simulations 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 Forecating model's (WRF) LES capability by implementing the Nonlinear Backscatter and Anisotropy (NBA) subfilter stress model following Kosoviæ (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. This work is performed under the auspices of the U.S. Department of Energy by Lawrence Livermore National Laboratory under Contract DE-AC52-07NA27344.

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

    SciTech Connect

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

    2008-09-08

    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.

  12. Wind turbine parameterizations implemented in WRF mesoscale-LES nested simulations

    NASA Astrophysics Data System (ADS)

    Marjanovic, N.; Mirocha, J. D.; Chow, F. K.

    2014-12-01

    Atmospheric simulations can be used to predict wind energy production at increasingly higher resolutions, which can better capture boundary layer processes and topography. Wind turbine performance depends on several different factors including local topography, weather conditions, and turbine spacing. In this work, we implement and examine the performance of a generalized actuator disk model (GAD) and a generalized actuator line model (GAL) in the Weather Research and Forecasting (WRF) model, a mesoscale atmospheric model. The wind turbine parameterizations are designed for turbulence-resolving simulations, and are used within downscaled large-eddy simulations (LES) forced with mesoscale simulations and WRF's grid nesting capability. The GAD represents the effects of thrust and torque created by a wind turbine on the atmosphere within a disk representing the rotor swept area. The forces applied by the turbine blades on the atmosphere are parameterized using blade-element theory and the aerodynamic properties of the blades. The GAL tracks the location of the individual turbine blades and applies thrust and tangential forces at the temporal location of each blade instead of distributing the total force of all the blades over the actuator disk like the GAD does. This should in theory increase fidelity but carries higher computational cost (~10 m for GAD vs. ~1 m resolution for GAL). Both GAD and GAL models include real-time yaw and pitch control to respond realistically to changing flow conditions. Comparisons are also made to help determine the importance of turbine blade tilt away from the tower and the inclusion of the tower and turbine hub drag effects. Our implementations are designed to permit simulation of turbine wake effects and turbine/airflow interactions within a realistic atmospheric boundary layer flow field, including resolved turbulence, time-evolving mesoscale forcing, and real topography. This work was performed under the auspices of the U

  13. Mesoscale acid deposition modeling studies

    NASA Technical Reports Server (NTRS)

    Kaplan, Michael L.; Proctor, F. H.; Zack, John W.; Karyampudi, V. Mohan; Price, P. E.; Bousquet, M. D.; Coats, G. D.

    1989-01-01

    The work performed in support of the EPA/DOE MADS (Mesoscale Acid Deposition) Project included the development of meteorological data bases for the initialization of chemistry models, the testing and implementation of new planetary boundary layer parameterization schemes in the MASS model, the simulation of transport and precipitation for MADS case studies employing the MASS model, and the use of the TASS model in the simulation of cloud statistics and the complex transport of conservative tracers within simulated cumuloform clouds. The work performed in support of the NASA/FAA Wind Shear Program included the use of the TASS model in the simulation of the dynamical processes within convective cloud systems, the analyses of the sensitivity of microburst intensity and general characteristics as a function of the atmospheric environment within which they are formed, comparisons of TASS model microburst simulation results to observed data sets, and the generation of simulated wind shear data bases for use by the aviation meteorological community in the evaluation of flight hazards caused by microbursts.

  14. Nested-model approach to investigate climate change

    USGS Publications Warehouse

    Hay, Lauren E.; Leavesley, George H.

    1994-01-01

    Determination of the spatial and temporal distribution of precipitation in mountainous regions is critical for assessing the effects of climate variability on water resources in these regions. Potential effects of climate change on water resources in the Gunnison River basin of southwestern Colorado currently are being studied using a nested-model approach to disaggregate large-scale general circulation model output to account for smaller-scale processes. This paper presents a disaggregation technique in which scenarios of possible climate change will be developed by nesting a global general circulation model, a mesoscale climate model, a local orographic precipitation model, and a watershed model.

  15. Numerical Modelling of Mesoscale Atmospheric Dispersion.

    NASA Astrophysics Data System (ADS)

    Moran, Michael D.

    Mesoscale atmospheric dispersion is more complicated than smaller-scale dispersion because the mean wind field can no longer be considered steady or horizontally homogeneous over mesoscale time and space scales. Wind shear also plays a more important role on the mesoscale, and horizontal dispersion can be enhanced and even dominated by vertical wind shear through either the simultaneous or delayed interaction of horizontal differential advection and vertical mixing over one or two diurnal periods. The CSU mesoscale atmospheric dispersion modelling system has been used in this study to simulate the transport and diffusion of a perfluorocarbon gas for episodic releases made during two North American mesoscale dispersion field experiments, the 1980 Great Plains tracer experiment and the 1983 Cross-Appalachian Tracer Experiment (CAPTEX). Ground -level and elevated tracer concentrations were measured out to distances of 600 km from the source in the first experiment and 1100 km in the second. The physiography of the two experimental domains was quite different, permitting isolation and examination of the roles of terrain forcing and differential advection in mesoscale atmospheric dispersion. Suites of numerical experiments of increasing complexity were carried out for both case studies. The experiments differed in the realism of their representation of both the synoptic-scale flow and the underlying terrain. The Great Plains nocturnal low-level jet played an important role in the first case while temporal changes in the synoptic -scale flow were very significant in the second case. The contributions of differential advection and mesoscale deformation to mesoscale dispersion dominated those of small-scale turbulent diffusion for both cases, and Pasquill's (1962) delayed-shear-enhancement mechanism for lateral dispersion was found to be particularly important. This study was also the first quantitative evaluation of the CSU mesoscale dispersion modelling system with

  16. Chemistry on the mesoscale: Modeling and measurement issues

    NASA Technical Reports Server (NTRS)

    Thompson, Anne; Pleim, John; Walcek, Christopher; Ching, Jason; Binkowski, Frank; Tao, Wei-Kuo; Dickerson, Russell; Pickering, Kenneth

    1993-01-01

    The topics covered include the following: Regional Acid Deposition Model (RADM) -- a coupled chemistry/mesoscale model; convection in RADM; unresolved issues for mesoscale modeling with chemistry -- nonprecipitating clouds; unresolved issues for mesoscale modeling with chemistry -- aerosols; tracer studies with Goddard Cumulus Ensemble Model (GCEM); field observations of trace gas transport in convection; and photochemical consequences of convection.

  17. Modeling mesoscale circulation of the Black Sea

    NASA Astrophysics Data System (ADS)

    Korotenko, K. A.

    2015-11-01

    An eddy-resolving (1/30)° version of the DieCAST low-dissipative model, adapted to the Black Sea circulation, is presented. Under mean climatological forcing, the model realistically reproduces major dominant large-scale and mesoscale structures of seasonal sea circulation, including the Rim Current, coastal anticyclonic eddies, mushroom currents, etc. Due to its extremely low dissipation and high resolution, the model makes it possible to trace the development of the baroclinic instability along the Turkish and Caucasian coasts, reproduce mesoscale structures generated by this mechanism, and assess the scales of these structures. The model also realistically reproduces short-term effects of bora winds on the evolution of subsurface layer structures.

  18. A history of mesoscale model development

    NASA Astrophysics Data System (ADS)

    Dudhia, Jimy

    2014-01-01

    The development of atmospheric mesoscale models from their early origins in the 1970's until the present day is described. Evolution has occurred in dynamical and physics representations in these models. The dynamics has had to change from hydrostatic to fully nonhydrostatic equations to handle the finer scales that have become possible in the last few decades with advancing computer power, which has enabled real-time forecasting to go to finer grid sizes. Meanwhile the physics has also become more sophisticated than the initial representations of the major processes associated with the surface, boundary layer, radiation, clouds and convection. As resolutions have become finer, mesoscale models have had to change paradigms associated with assumptions related to what is considered sub-grid scale needing parameterization, and what is resolved well enough to be explicitly handled by the dynamics. This first occurred with cumulus parameterization as real-time forecast models became able to represent individual updrafts, and is now starting to occur in the boundary layer as future forecast models may be able resolve individual thermals. Beyond that, scientific research has provided a greater understanding of detailed microphysical and land-surface processes that are important to aspects of weather prediction, and these parameterizations have been developing complexity at a steady rate. This paper can just give a perspective of these developments in the broad field of research associated with mesoscale atmospheric model development.

  19. DEVELOPMENT OF MESOSCALE AIR QUALITY SIMULATION MODELS. VOLUME 6. USER'S GUIDE TO MESOPAC (MESOSCALE METEOROLOGY PACKAGE)

    EPA Science Inventory

    MESOPAC is a mesoscale meteorological preprocessor program; it is designed to provide meteorological data to regional-scale air quality simulation models. Radiosonde data routinely available from National Weather Service (NWS) radiosonde ('upper air') and surface stations are use...

  20. Mesoscale modelling of PBX. Binder effects.

    NASA Astrophysics Data System (ADS)

    Milne, Alec; Dunnett, Jim; Bourne, Neil

    2007-06-01

    In earlier work we have studied aspects of shock to detonation transition and detonation structure in polymer bonded explosives on the scale of the largest grains (the mesoscale) to augment continuum models for these processes. Building blocks have been unreacted Hugoniots of mixtures, mapping from experiment (2D micrographs and 3D tomography) for accurate initial conditions and details of cavity collapse mechanisms as hot spots for ignition. Recently we have applied continuum mixture theory (multi-phase modelling) to dirty binder (the mixture of explosive crystal fines and binder that surrounds the large grains) and validated it for the unreacted Hugoniot of a range of UK explosives. In this paper we build on all of this work and report our progress in using continuum mixture theory to model the reactive behaviour of dirty binder. We begin by considering the binder on its own and then use this continuum mixture mode in conjunction with mesoscale representations of PBX. We consider PBX9501 and a UK PBX as examples. We identify the numerical modelling issues that have arisen, our current approaches and our plans for further development and testing.

  1. Probabilistic, meso-scale flood loss modelling

    NASA Astrophysics Data System (ADS)

    Kreibich, Heidi; Botto, Anna; Schröter, Kai; Merz, Bruno

    2016-04-01

    Flood risk analyses are an important basis for decisions on flood risk management and adaptation. However, such analyses are associated with significant uncertainty, even more if changes in risk due to global change are expected. Although uncertainty analysis and probabilistic approaches have received increased attention during the last years, they are still not standard practice for flood risk assessments and even more for flood loss modelling. State of the art in flood loss modelling is still the use of simple, deterministic approaches like stage-damage functions. Novel probabilistic, multi-variate flood loss models have been developed and validated on the micro-scale using a data-mining approach, namely bagging decision trees (Merz et al. 2013). In this presentation we demonstrate and evaluate the upscaling of the approach to the meso-scale, namely on the basis of land-use units. The model is applied in 19 municipalities which were affected during the 2002 flood by the River Mulde in Saxony, Germany (Botto et al. submitted). The application of bagging decision tree based loss models provide a probability distribution of estimated loss per municipality. Validation is undertaken on the one hand via a comparison with eight deterministic loss models including stage-damage functions as well as multi-variate models. On the other hand the results are compared with official loss data provided by the Saxon Relief Bank (SAB). The results show, that uncertainties of loss estimation remain high. Thus, the significant advantage of this probabilistic flood loss estimation approach is that it inherently provides quantitative information about the uncertainty of the prediction. References: Merz, B.; Kreibich, H.; Lall, U. (2013): Multi-variate flood damage assessment: a tree-based data-mining approach. NHESS, 13(1), 53-64. Botto A, Kreibich H, Merz B, Schröter K (submitted) Probabilistic, multi-variable flood loss modelling on the meso-scale with BT-FLEMO. Risk Analysis.

  2. Numerical modelling of mesoscale atmospheric dispersion. (Volumes I and II)

    SciTech Connect

    Moran, M.D.

    1992-01-01

    Mesoscale atmospheric dispersion is more complicated than smaller-scale dispersion because the mean wind field can no longer be considered steady or horizontally homogeneous over mesoscale time and space scales. Wind shear also plays an important role on the mesoscale, and horizontal dispersion can be enhanced and even dominated by vertical wind shear through either the simultaneous or delayed interaction of horizontal differential advection and vertical mixing. The CSU mesoscale atmospheric dispersion modelling system has been used in this study to simulate the transport and diffusion of a perfluorocarbon gas for episodic releases made during two mesoscale dispersion field experiments. The physiography of the two experimental domains was quite different, permitting isolation and examination of the roles of terrain forcing and differential advection in mesoscale atmospheric dispersion. Suites of numerical experiments of increasing complexity were carried out for both case studies. The experiments differed in the realism of their representation of both the synoptic-scale flow and the underlying terrain. The contributions of differential advection and mesoscale deformation to mesoscale dispersion dominated those of small-scale turbulent diffusion for both cases, and Pasquill's (1962) delayed-shear-enhancement mechanism for lateral dispersion was found to be particularly important. This study was also the first quantitative evaluation of the CSU mesoscale dispersion modelling system with episodic mesoscale dispersion field data. The modelling system showed considerable skill in predicting quantitative tracer-cloud characteristics such as peak concentration, maximum cloud width, arrival time, transit time, and crosswind integrated exposure. Model predictions also compared favorably with predictions made by a number of other mesoscale dispersion models for the same two case studies.

  3. Nested ocean models: Work in progress

    NASA Technical Reports Server (NTRS)

    Perkins, A. Louise

    1991-01-01

    The ongoing work of combining three existing software programs into a nested grid oceanography model is detailed. The HYPER domain decomposition program, the SPEM ocean modeling program, and a quasi-geostrophic model written in England are being combined into a general ocean modeling facility. This facility will be used to test the viability and the capability of two-way nested grids in the North Atlantic.

  4. Assessing nested hydrological and hydrochemical behaviour of a mesoscale catchment using continuous tracer data

    NASA Astrophysics Data System (ADS)

    Tetzlaff, D.; Waldron, S.; Brewer, M. J.; Soulsby, C.

    2007-04-01

    SummaryHigh resolution (15 min) continuous environmental tracer data (conductivity, pH and derived Gran alkalinity) were used to investigate the hydrological functioning of the 233 km 2 Feugh catchment in NE Scotland and two of its nested sub-catchments (42 km 2 and 1 km 2). Over the 2003-2004 hydrological year, a fine resolution Gran alkalinity time series was derived and indicated detailed and subtle changes in stream chemistry. Diurnal variation in alkalinity and flow were observed under low flow conditions, attributed to instream-respiration and riparian-evapotranspiration respectively. At high flows, abrupt threshold-like behaviour was evident during storm events as hydrological sources in the acidic surface horizons of the catchment soils replace groundwater as the dominant source of runoff. Using Gran alkalinity to define end-member compositions, chemically-based hydrograph separations revealed that as catchment scale increased, groundwater contributions to annual runoff increased from 52 ± 10%, to 67 ± 6%, to 70 ± 11%. This is consistent with previous mean residence times (MRT) estimated from weekly δ 18O data which respectively increased from 1.3-4.7 months -1 to 2.4-10.6 months -1 to 2.5-11.1 months -1. Linking continuous tracer data with GIS interpretation of landscape characteristics increased the sophistication of our conceptual model of catchment processes. Increasing dominance of responsive peaty soils leads to more saturation overland flow, increased flashiness of runoff, reduced groundwater recharge, reduced MRTs and more marked diurnal variations in flow, which drive concomitant difference in hydrochemistry. Conversely, increased cover of free-draining soils and aquifers in drift, reduced flashiness, increased groundwater contributions and increased MRTs. It is proposed that high resolution tracer data, in conjunction with other measurements defining catchment characteristics, represent a resource and challenge to modellers if models can be

  5. Evaluation of Mesoscale Model Phenomenological Verification Techniques

    NASA Technical Reports Server (NTRS)

    Lambert, Winifred

    2006-01-01

    Forecasters at the Spaceflight Meteorology Group, 45th Weather Squadron, and National Weather Service in Melbourne, FL use mesoscale numerical weather prediction model output in creating their operational forecasts. These models aid in forecasting weather phenomena that could compromise the safety of launch, landing, and daily ground operations and must produce reasonable weather forecasts in order for their output to be useful in operations. Considering the importance of model forecasts to operations, their accuracy in forecasting critical weather phenomena must be verified to determine their usefulness. The currently-used traditional verification techniques involve an objective point-by-point comparison of model output and observations valid at the same time and location. The resulting statistics can unfairly penalize high-resolution models that make realistic forecasts of a certain phenomena, but are offset from the observations in small time and/or space increments. Manual subjective verification can provide a more valid representation of model performance, but is time-consuming and prone to personal biases. An objective technique that verifies specific meteorological phenomena, much in the way a human would in a subjective evaluation, would likely produce a more realistic assessment of model performance. Such techniques are being developed in the research community. The Applied Meteorology Unit (AMU) was tasked to conduct a literature search to identify phenomenological verification techniques being developed, determine if any are ready to use operationally, and outline the steps needed to implement any operationally-ready techniques into the Advanced Weather Information Processing System (AWIPS). The AMU conducted a search of all literature on the topic of phenomenological-based mesoscale model verification techniques and found 10 different techniques in various stages of development. Six of the techniques were developed to verify precipitation forecasts, one

  6. Numerical modelling of mesoscale atmospheric dispersion, volumes 1 and 2

    NASA Astrophysics Data System (ADS)

    Moran, Michael D.

    Mesoscale atmospheric dispersion is more complicated than smaller scale dispersion because the mean wind field can no longer be considered steady or horizontally homogeneous over mesoscale time and space scales. Wind shear also plays a more important role on the mesoscale and horizontal dispersion can be enhanced and even dominated by vertical wind shear through either the simultaneous or delayed interaction of horizontal differential advection and vertical mixing over one or two diurnal periods. The CSU mesoscale atmospheric dispersion modeling system was used to simulate the transport and diffusion of a perfluorocarbon gas for episodic releases made during two North American mesoscale dispersion field experiments, the 1980 Great Plains tracer experiment and the 1983 Cross-Appalachian Tracer Experiment (CAPTEX). Ground-level and elevated tracer concentrations were measured out to distances of 600 km from the source in the first experiment and 1100 km in the second. The physiography of the two experimental domains was quite different, permitting isolation and examination of the roles of terrain forcing and differential advection in mesoscale atmospheric dispersion. Suites of numerical experiments of increasing complexity were carried out for both case studies. The experiments differed in the realism of their representation of both the synoptic-scale flow and the underlying terrain. The Great Plains nocturnal low-level jet played an important role in the first case while temporal changes in the synoptic-scale flow were very significant in the second case. The contributions of differential advection and mesoscale deformation to mesoscale dispersion dominated those of small-scale turbulent diffusion for both cases, and Pasquills delayed-shear-enhancement mechanism for lateral dispersion was found to be particularly important. The first quantitative evaluation of the CSU mesoscale dispersion modeling system with episodic mesoscale dispersion field data was presented

  7. Modeling Basin-scale Runoffs with Precipitation Data from Ground-based Observations and Mesoscale Simulations

    NASA Astrophysics Data System (ADS)

    Li, M.; Yang, M.; Soong, R.; Hwang, S.

    2002-12-01

    The purpose of this study is to investigate the applicability of distributed basin-scale runoff modeling, driven by rainfall data from either ground-based observations or mesoscale simulations, in response to typhoons invading Taiwan. Typhoons Herb (1996) and Zeb (1998) were selected for calibrating the runoff parameters reflecting the landuse conditions in the basin and evaluating the applicability of observed and simulated rainfall data toward runoff estimations, respectively. Upstream basins of Reservoir Shihmen with a drainage area of 764 km2 and Reservoir Feitsui with a drainage area of 303 km2 were the domains of interest in this preliminary study. Ground-based observations of both stream flows and station rainfalls were collected in an hourly resolution. The mesoscale model,MM5, simulation for Herb was conducted in 4-nested grids with the finest resolution of 2.2 km and 2-nested grids with the finest resolution of 15 km for Zeb, and the time resolution for both cases was 5 minutes. Accumulated total rain was accommodated with terrain elevation in MM5 simulations and station data to provide areal rainfall distributions. While the ground-based observations were sparse and incapable of correctly representing areal rainfall characteristics, the MM5 simulated data may introduce great uncertainties in basin-scale hydrological applications. The experience learned from this study is expected to provide an applicable approach with both ground-based observations and mesoscale simulations in basin-scale runoff computations.

  8. Evaluation of simple mesoscale models for use in TESS

    NASA Astrophysics Data System (ADS)

    Miller, R. J.; Sampson, C. R.

    1991-11-01

    Prediction of wind flow in a complex coastal environment is a challenging task that continues to be of interest to the U.S. Navy, specifically for use in the Tactical Environmental Support System (TESS). TESS is a computer workstation which provides environmental information for the Navy's tactical decision makers and is discussed in detail in Phegley and Crosiar (1991). According to Mass and Dempsey (1986), global and regional models have improved to the point where the adequately predict larger scale synoptic conditions; however, conversion of these forecasts into local and mesoscale weather is still a problem. One solution is to increase the resolution of a global or regional model to that desired for mesoscale prediction. The problem with this is that computational requirements for the model would far exceed the capability of TESS. Another solution is to run simple mesoscale models which use observations or output from the more complex models for initialization. Until recently, computational requirements of simple mesoscale models were beyond the capabilities of TESS. However, the TESS hardware has been upgraded to a system which is now capable of running simple mesoscale models.

  9. Modelling granite migration by mesoscale pervasive flow

    NASA Astrophysics Data System (ADS)

    Leitch, A. M.; Weinberg, R. F.

    2002-06-01

    Mesoscale pervasive magma migration leads to granite injection complexes, common in hot crustal terranes. Pervasive migration is limited by magma freezing when intruding cold country rock. Here, we explore numerically the feedback mechanism between magma intrusion and heating of the country rock, which allows younger intrusive batches to reach increasingly shallower/cooler levels. This process relies on the higher solidus temperature of a rock compared to that of its melt, once melt is segregated. We define the 'free-ride layer' as the region above the melt source, where magma may freely migrate because rock temperature is above melt solidus. The top of the free-ride layer, which corresponds to the melt solidus ( TS) isotherm, is at the 'limiting depth', zS. After magma passes through the free-ride layer, the magma 'front' is always at the limiting depth. We modeled the thickening and heating of the crust above the source as melt at its liquidus ( TL) intrudes it pervasively from below. We found that: (a) magma quickly warms crust below zS to about TL, forming a step in temperature at zS; (b) the front ( zS) moves up through the crust as more magma is intruded; (c) as magma is emplaced at the front, a mingled layer of about half magma half crust forms below it, so that the total rise of the front corresponds approximately to half of the thickness of magma added to the free-ride layer; (d) the rate of rise of the front depends on the temperature difference between crust and TL, and slows down as the magma front rises; (e) for most reasonable intrusion rates and volumes, the crust above zS feels little influence of the intrusion, because the diffusion time scale is much smaller than the rise rate of the front. In summary, pervasive migration is an efficient way of heating the lower to middle crust, and can result in an injection complex several kilometers thick, consisting of about half magma and half original crust.

  10. Recent Applications of Mesoscale Modeling to Nanotechnology and Drug Delivery

    SciTech Connect

    Maiti, A; Wescott, J; Kung, P; Goldbeck-Wood, G

    2005-02-11

    Mesoscale simulations have traditionally been used to investigate structural morphology of polymer in solution, melts and blends. Recently we have been pushing such modeling methods to important areas of Nanotechnology and Drug delivery that are well out of reach of classical molecular dynamics. This paper summarizes our efforts in three important emerging areas: (1) polymer-nanotube composites; (2) drug diffusivity through cell membranes; and (3) solvent exchange in nanoporous membranes. The first two applications are based on a bead-spring-based approach as encoded in the Dissipative Particle Dynamics (DPD) module. The last application used density-based Mesoscale modeling as implemented in the Mesodyn module.

  11. Mesoscale modeling of solute precipitation and radiation damage

    SciTech Connect

    Zhang, Yongfeng; Schwen, Daniel; Ke, Huibin; Bai, Xianming; Hales, Jason

    2015-09-01

    This report summarizes the low length scale effort during FY 2014 in developing mesoscale capabilities for microstructure evolution in reactor pressure vessels. During operation, reactor pressure vessels are subject to hardening and embrittlement caused by irradiation-induced defect accumulation and irradiation-enhanced solute precipitation. Both defect production and solute precipitation start from the atomic scale, and manifest their eventual effects as degradation in engineering-scale properties. To predict the property degradation, multiscale modeling and simulation are needed to deal with the microstructure evolution, and to link the microstructure feature to material properties. In this report, the development of mesoscale capabilities for defect accumulation and solute precipitation are summarized. Atomic-scale efforts that supply information for the mesoscale capabilities are also included.

  12. Budget study of a mesoscale convective system - Model simulation

    NASA Technical Reports Server (NTRS)

    Tao, Wei-Kuo; Simpson, Joanne; Mccumber, Michael

    1988-01-01

    A tropical squall-type cloud cluster is examined as an example of a mesoscale convective complex. The precipitation growth processes and air circulations that develop in the convective and stratiform regions are studied using a data set generated from a time-dependent numerical cloud model. The relationship of the stratiform region of the mesoscale convective complex is discussed. The vertical profiles of heating and drying are calculated. Comparisons are made between simulations with and without ice-phase microphysical processes and a simulation with forcing by weaker lifting at middle and upper levels.

  13. Massively parallel implementation of the Penn State/NCAR Mesoscale Model

    SciTech Connect

    Foster, I.; Michalakes, J.

    1992-01-01

    Parallel computing promises significant improvements in both the raw speed and cost performance of mesoscale atmospheric models. On distributed-memory massively parallel computers available today, the performance of a mesoscale model will exceed that of conventional supercomputers; on the teraflops machines expected within the next five years, performance will increase by several orders of magnitude. As a result, scientists will be able to consider larger problems, more complex model processes, and finer resolutions. In this paper. we report on a project at Argonne National Laboratory that will allow scientists to take advantage of parallel computing technology. This Massively Parallel Mesoscale Model (MPMM) will be functionally equivalent to the Penn State/NCAR Mesoscale Model (MM). In a prototype study, we produced a parallel version of MM4 using a static (compile-time) coarse-grained patch'' decomposition. This code achieves one-third the performance of a one-processor CRAY Y-MP on twelve Intel 1860 microprocessors. The current version of MPMM is based on all MM5 and uses a more fine-grained approach, decomposing the grid as finely as the mesh itself allows so that each horizontal grid cell is a parallel process. This will allow the code to utilize many hundreds of processors. A high-level language for expressing parallel programs is used to implement communication strearns between the processes in a way that permits dynamic remapping to the physical processors of a particular parallel computer. This facilitates load balancing, grid nesting, and coupling with graphical systems and other models.

  14. Massively parallel implementation of the Penn State/NCAR Mesoscale Model

    SciTech Connect

    Foster, I.; Michalakes, J.

    1992-12-01

    Parallel computing promises significant improvements in both the raw speed and cost performance of mesoscale atmospheric models. On distributed-memory massively parallel computers available today, the performance of a mesoscale model will exceed that of conventional supercomputers; on the teraflops machines expected within the next five years, performance will increase by several orders of magnitude. As a result, scientists will be able to consider larger problems, more complex model processes, and finer resolutions. In this paper. we report on a project at Argonne National Laboratory that will allow scientists to take advantage of parallel computing technology. This Massively Parallel Mesoscale Model (MPMM) will be functionally equivalent to the Penn State/NCAR Mesoscale Model (MM). In a prototype study, we produced a parallel version of MM4 using a static (compile-time) coarse-grained ``patch`` decomposition. This code achieves one-third the performance of a one-processor CRAY Y-MP on twelve Intel 1860 microprocessors. The current version of MPMM is based on all MM5 and uses a more fine-grained approach, decomposing the grid as finely as the mesh itself allows so that each horizontal grid cell is a parallel process. This will allow the code to utilize many hundreds of processors. A high-level language for expressing parallel programs is used to implement communication strearns between the processes in a way that permits dynamic remapping to the physical processors of a particular parallel computer. This facilitates load balancing, grid nesting, and coupling with graphical systems and other models.

  15. Driving Mesoscale Processes with Global Data Assimilative Models (Invited)

    NASA Astrophysics Data System (ADS)

    Bust, G. S.; Comberiate, J.; Datta-Barua, S.

    2013-12-01

    Global large scale ionosphere-thermosphere (IT) data assimilation methods have evolved to the point where they are able to estimate several IT state variables simultaneously over the entire globe.The large scale state variables estimated by data assimilative techniques can then be used to drive physical models of mesoscale and small scale processes. This allows for the possibility of being able to accurately predict mesoscale and small scale processes and structures from knowledge of the large scale driving physics. However, the accuracy of any such predictions will depend a) upon the accuracy of the estimated large scale state variables from data assimilation as well as b) the accuracy of the mesoscale and small scale models. In this presentation, we will focus upon the current capability of the data assimilation models IDA4D and EMPIRE to accurately estimate large scale IT state variables at equatorial latitudes. We will then discuss how these large scale state variables can be used to drive mesoscale models of the equatorial ionosphere and thermosphere. Results will be presented of large scale estimates of equatorial electron density and electric potential from analysis of IDA4D/EMPIRE and ingestion of C/NOFS observations

  16. Assimilation of GOES Land Surface Data into a Mesoscale Models

    NASA Technical Reports Server (NTRS)

    Lapenta, William M.; Suggs, Ron; McNider, Richard T.; Jedlovec, Gary; Dembek, Scott; Goodman, H. Michael (Technical Monitor)

    2001-01-01

    A technique has been developed for assimilating Geostationary Operational Environmental Satellite (GOES)-derived skin temperature tendencies and insolation into the surface energy budget equation of a mesoscale model so that the simulated rate of temperature change closely agrees with the satellite observations. A critical assumption of the technique is that the availability of moisture (either from the soil or vegetation) is the least known term in the model's surface energy budget. Therefore, the simulated latent heat flux, which is a function of surface moisture availability, is adjusted based upon differences between the modeled and satellite-observed skin temperature tendencies. An advantage of this technique is that satellite temperature tendencies are assimilated in an energetically consistent manner that avoids energy imbalances and surface stability problems that arise from direct assimilation of surface shelter temperatures. The fact that the rate of change of the satellite skin temperature is used rather than the absolute temperature means that sensor calibration is not as critical. The assimilation technique has been applied to the Oklahoma-Kansas region during the spring-summer 2000 time period when dynamic changes in vegetation cover occur. In April, central Oklahoma is characterized by large NDVI associated with winter wheat while surrounding areas are primarily rangeland with lower NDVI. In July the vegetation pattern reverses as the central wheat area changes to low NDVI due to harvesting and the surrounding rangeland is greener than it was in April. The goal of this study is to determine if assimilating satellite land surface data can improve simulation of the complex spatial distribution of surface energy and water fluxes across this region. The PSU/NCAR NM5 V3 system is used in this study. The grid configuration consists of a 36-km CONUS domain and a 12-km nest over the area of interest. Bulk verification statistics (BIAS and RMSE) of surface

  17. Numerical Model Studies of the Martian Mesoscale Circulations

    NASA Technical Reports Server (NTRS)

    Segal, Moti; Arritt, Raymond W.

    1997-01-01

    The study objectives were to evaluate by numerical modeling various possible mesoscale circulation on Mars and related atmospheric boundary layer processes. The study was in collaboration with J. Tillman of the University of Washington (who supported the study observationally). Interaction has been made with J. Prusa of Iowa State University in numerical modeling investigation of dynamical effects of topographically-influenced flow. Modeling simulations included evaluations of surface physical characteristics on: (i) the Martian atmospheric boundary layer and (ii) their impact on thermally and dynamically forced mesoscale flows. Special model evaluations were made in support of selection of the Pathfinder landing sites. J. Tillman's finding of VL-2 inter-annual temperature difference was followed by model simulations attempting to point out the forcing for this feature. Publication of the results in the reviewed literature in pending upon completion of the manuscripts in preparation as indicated later.

  18. Mesoscale Modeling of LX-17 Under Isentropic Compression

    SciTech Connect

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

    2010-03-06

    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.

  19. ROCKY MOUNTAIN ACID DEPOSITION MODEL ASSESSMENT: ACID RAIN MOUNTAIN MESOSCALE MODEL (ARM3)

    EPA Science Inventory

    The Acid Rain Mountain Mesoscale Model (ARM3) is a mesoscale acid deposition/air quality model that was developed for calculating incremental acid deposition (sulfur and nitrogen species) and pollutant concentration impacts in complex terrain. The model was set up for operation w...

  20. Mesoscale structures in the Subarctic Seas - observations and modelling

    NASA Astrophysics Data System (ADS)

    Walczowski, W.; Maslowski, W.

    2003-04-01

    Scientists from IO PAS have investigated the sub-arctic seas since 1989. In this study we present data collected by the IO PAS in contribution to VEINS project as well as from the other cruises conducted by R.V. Oceania in the Barents, Norwegian and Greenland seas. Observed mesoscale structures will be compared with results from two high-resolution models of the Pan-Arctic region forced with realistic atmospheric fields. The first model is configured at 1/6°(~18 km) and 30-layer grid and the second at 1/12° (~9 km) and 45-layer grid. Both models are developed at the Naval Postgraduate School, Monterey. Based on in situ measurements and model output, we specify regions of high mesoscale activity, which exist mainly along the Barents slope, in the area west of Spitsbergen and along the Arctic Front, separating water of Atlantic origin from the Greenland Sea Gyre. A comparison between current patterns, total kinetic energy (TKE) and eddy kinetic energy (EKE) calculated from the models and from in situ data will be presented. We will analyse observed mesoscale structures including frontal meanders and intrusions, cyclonic and anticyclonic eddies, and dense water plumes. Selected phenomena will be compared with modelled structures. Investigations of the Arctic Front show that mesoscale eddies and intrusions play an important role in the cross-frontal volume, salt and heat exchanges. Anticyclonic eddies originating from the frontal meanders carry considerable volume of Atlantic Water into the Greenland Sea. The transport of Atlantic Water from the Norwegian Sea into the Greenland Sea Gyre will be analysed based on field data and eddy-permitting model output. Anticyclonic eddies originating to the west of Spitsbergen play an important role in the recirculation of Atlantic Water in Fram Strait. Observed and modelled processes and pathways of the recirculation of Atlantic Water will be presented.

  1. Estimation of Eddy Dissipation Rates from Mesoscale Model Simulations

    NASA Technical Reports Server (NTRS)

    Ahmad, Nashat N.; Proctor, Fred H.

    2012-01-01

    The Eddy Dissipation Rate is an important metric for representing the intensity of atmospheric turbulence and is used as an input parameter for predicting the decay of aircraft wake vortices. In this study, the forecasts of eddy dissipation rates obtained from the current state-of-the-art mesoscale model are evaluated for terminal area applications. The Weather Research and Forecast mesoscale model is used to simulate the planetary boundary layer at high horizontal and vertical mesh resolutions. The Bougeault-Lacarrer and the Mellor-Yamada-Janji schemes implemented in the Weather Research and Forecast model are evaluated against data collected during the National Aeronautics and Space Administration s Memphis Wake Vortex Field Experiment. Comparisons with other observations are included as well.

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

    SciTech Connect

    Michalakes, J.G.

    1997-08-01

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

  3. A simple generative model of the mouse mesoscale connectome

    PubMed Central

    Henriksen, Sid; Pang, Rich; Wronkiewicz, Mark

    2016-01-01

    Recent technological advances now allow for the collection of vast data sets detailing the intricate neural connectivity patterns of various organisms. Oh et al. (2014) recently published the most complete description of the mouse mesoscale connectome acquired to date. Here we give an in-depth characterization of this connectome and propose a generative network model which utilizes two elemental organizational principles: proximal attachment ‒ outgoing connections are more likely to attach to nearby nodes than to distant ones, and source growth ‒ nodes with many outgoing connections are likely to form new outgoing connections. We show that this model captures essential principles governing network organization at the mesoscale level in the mouse brain and is consistent with biologically plausible developmental processes. DOI: http://dx.doi.org/10.7554/eLife.12366.001 PMID:26978793

  4. Animal Models and Integrated Nested Laplace Approximations

    PubMed Central

    Holand, Anna Marie; Steinsland, Ingelin; Martino, Sara; Jensen, Henrik

    2013-01-01

    Animal models are generalized linear mixed models used in evolutionary biology and animal breeding to identify the genetic part of traits. Integrated Nested Laplace Approximation (INLA) is a methodology for making fast, nonsampling-based Bayesian inference for hierarchical Gaussian Markov models. In this article, we demonstrate that the INLA methodology can be used for many versions of Bayesian animal models. We analyze animal models for both synthetic case studies and house sparrow (Passer domesticus) population case studies with Gaussian, binomial, and Poisson likelihoods using INLA. Inference results are compared with results using Markov Chain Monte Carlo methods. For model choice we use difference in deviance information criteria (DIC). We suggest and show how to evaluate differences in DIC by comparing them with sampling results from simulation studies. We also introduce an R package, AnimalINLA, for easy and fast inference for Bayesian Animal models using INLA. PMID:23708299

  5. Functional Error Models to Accelerate Nested Sampling

    NASA Astrophysics Data System (ADS)

    Josset, L.; Elsheikh, A. H.; Demyanov, V.; Lunati, I.

    2014-12-01

    The main challenge in groundwater problems is the reliance on large numbers of unknown parameters with wide rage of associated uncertainties. To translate this uncertainty to quantities of interest (for instance the concentration of pollutant in a drinking well), a large number of forward flow simulations is required. To make the problem computationally tractable, Josset et al. (2013, 2014) introduced the concept of functional error models. It consists in two elements: a proxy model that is cheaper to evaluate than the full physics flow solver and an error model to account for the missing physics. The coupling of the proxy model and the error models provides reliable predictions that approximate the full physics model's responses. The error model is tailored to the problem at hand by building it for the question of interest. It follows a typical approach in machine learning where both the full physics and proxy models are evaluated for a training set (subset of realizations) and the set of responses is used to construct the error model using functional data analysis. Once the error model is devised, a prediction of the full physics response for a new geostatistical realization can be obtained by computing the proxy response and applying the error model. We propose the use of functional error models in a Bayesian inference context by combining it to the Nested Sampling (Skilling 2006; El Sheikh et al. 2013, 2014). Nested Sampling offers a mean to compute the Bayesian Evidence by transforming the multidimensional integral into a 1D integral. The algorithm is simple: starting with an active set of samples, at each iteration, the sample with the lowest likelihood is kept aside and replaced by a sample of higher likelihood. The main challenge is to find this sample of higher likelihood. We suggest a new approach: first the active set is sampled, both proxy and full physics models are run and the functional error model is build. Then, at each iteration of the Nested

  6. Mesoscale modeling of metal-loaded high explosives

    SciTech Connect

    Bdzil, John Bohdan; Lieberthal, Brandon; Srewart, Donald S

    2010-01-01

    We describe a 3D approach to modeling multi-phase blast explosive, which is primarily condensed explosive by volume with inert embedded particles. These embedded particles are uniform in size and placed on the array of a regular lattice. The asymptotic theory of detonation shock dynamics governs the detonation shock propagation in the explosive. Mesoscale hydrodynamic simulations are used to show how the particles are compressed, deformed, and accelerated by the high-speed detonation products flow.

  7. Anisotropic Mesoscale Eddy Transport in Ocean General Circulation Models

    NASA Astrophysics Data System (ADS)

    Reckinger, S. J.; Fox-Kemper, B.; Bachman, S.; Bryan, F.; Dennis, J.; Danabasoglu, G.

    2014-12-01

    Modern climate models are limited to coarse-resolution representations of large-scale ocean circulation that rely on parameterizations for mesoscale eddies. The effects of eddies are typically introduced by relating subgrid eddy fluxes to the resolved gradients of buoyancy or other tracers, where the proportionality is, in general, governed by an eddy transport tensor. The symmetric part of the tensor, which represents the diffusive effects of mesoscale eddies, is universally treated isotropically in general circulation models. Thus, only a single parameter, namely the eddy diffusivity, is used at each spatial and temporal location to impart the influence of mesoscale eddies on the resolved flow. However, the diffusive processes that the parameterization approximates, such as shear dispersion, potential vorticity barriers, oceanic turbulence, and instabilities, typically have strongly anisotropic characteristics. Generalizing the eddy diffusivity tensor for anisotropy extends the number of parameters to three: a major diffusivity, a minor diffusivity, and the principal axis of alignment. The Community Earth System Model (CESM) with the anisotropic eddy parameterization is used to test various choices for the newly introduced parameters, which are motivated by observations and the eddy transport tensor diagnosed from high resolution simulations. Simply setting the ratio of major to minor diffusivities to a value of five globally, while aligning the major axis along the flow direction, improves biogeochemical tracer ventilation and reduces global temperature and salinity biases. These effects can be improved even further by parameterizing the anisotropic transport mechanisms in the ocean.

  8. Development and analysis of prognostic equations for mesoscale kinetic energy and mesoscale (subgrid scale) fluxes for large-scale atmospheric models

    NASA Technical Reports Server (NTRS)

    Avissar, Roni; Chen, Fei

    1993-01-01

    Generated by landscape discontinuities (e.g., sea breezes) mesoscale circulation processes are not represented in large-scale atmospheric models (e.g., general circulation models), which have an inappropiate grid-scale resolution. With the assumption that atmospheric variables can be separated into large scale, mesoscale, and turbulent scale, a set of prognostic equations applicable in large-scale atmospheric models for momentum, temperature, moisture, and any other gaseous or aerosol material, which includes both mesoscale and turbulent fluxes is developed. Prognostic equations are also developed for these mesoscale fluxes, which indicate a closure problem and, therefore, require a parameterization. For this purpose, the mean mesoscale kinetic energy (MKE) per unit of mass is used, defined as E-tilde = 0.5 (the mean value of u'(sub i exp 2), where u'(sub i) represents the three Cartesian components of a mesoscale circulation (the angle bracket symbol is the grid-scale, horizontal averaging operator in the large-scale model, and a tilde indicates a corresponding large-scale mean value). A prognostic equation is developed for E-tilde, and an analysis of the different terms of this equation indicates that the mesoscale vertical heat flux, the mesoscale pressure correlation, and the interaction between turbulence and mesoscale perturbations are the major terms that affect the time tendency of E-tilde. A-state-of-the-art mesoscale atmospheric model is used to investigate the relationship between MKE, landscape discontinuities (as characterized by the spatial distribution of heat fluxes at the earth's surface), and mesoscale sensible and latent heat fluxes in the atmosphere. MKE is compared with turbulence kinetic energy to illustrate the importance of mesoscale processes as compared to turbulent processes. This analysis emphasizes the potential use of MKE to bridge between landscape discontinuities and mesoscale fluxes and, therefore, to parameterize mesoscale fluxes

  9. Computational Modeling of Heterogeneous Reactive Materials at the Mesoscale

    NASA Astrophysics Data System (ADS)

    Baer, Mel R.

    1999-06-01

    Nearly all energetic materials, including explosives, pyrotechnics, propellants and intermetallics are heterogeneous and typically consist of a mixture of crystalline constituents and binders. These materials exhibit distinctly different thermal/mechanical/chemical behavior than pure materials because microstructure introduces internal boundary effects at the mesoscale. For example, the threshold to reaction is known to be greatly influenced by changes in crystal morphology, size, defect content and particle distribution. Much of current work in computational modeling describes macroscale behavior based on continuum theory or microscopic/atomistic behavior using molecular dynamics methods. The mesoscale has not been as extensively studied yet it is the level that bridges continuum and atomistic scales. Shock physics analysis can now take advantage of new parallel computing machines to provide improved resolution of shock processes at the mesoscale. This presentation discusses three-dimensional numerical simulations of shock impact on a realistic ensemble of crystalline grains. Detailed wave fields are resolved including the effects of material strength, thermal dissipation and reaction. Numerical simulations demonstrate that rapid material distortion occurs at crystal boundaries and the localization of energy produces hot-spots due to the effects of shock focusing and plastic work as material flows into interstitial regions. These studies provide new insights into the micromechanical behavior of heterogeneous energetic materials strongly suggesting that initiation and reaction of shocked heterogeneous materials involve states distinctly different from single jump states. The recent enhancements in numerical modeling due to massively-parallel computing pose new challenges for the development of novel experimental capabilities that can provide the detailed information of appropriate material descriptions and interface conditions at the mesoscale.

  10. Adaptation of Mesoscale Weather Models to Local Forecasting

    NASA Technical Reports Server (NTRS)

    Manobianco, John T.; Taylor, Gregory E.; Case, Jonathan L.; Dianic, Allan V.; Wheeler, Mark W.; Zack, John W.; Nutter, Paul A.

    2003-01-01

    Methodologies have been developed for (1) configuring mesoscale numerical weather-prediction models for execution on high-performance computer workstations to make short-range weather forecasts for the vicinity of the Kennedy Space Center (KSC) and the Cape Canaveral Air Force Station (CCAFS) and (2) evaluating the performances of the models as configured. These methodologies have been implemented as part of a continuing effort to improve weather forecasting in support of operations of the U.S. space program. The models, methodologies, and results of the evaluations also have potential value for commercial users who could benefit from tailoring their operations and/or marketing strategies based on accurate predictions of local weather. More specifically, the purpose of developing the methodologies for configuring the models to run on computers at KSC and CCAFS is to provide accurate forecasts of winds, temperature, and such specific thunderstorm-related phenomena as lightning and precipitation. The purpose of developing the evaluation methodologies is to maximize the utility of the models by providing users with assessments of the capabilities and limitations of the models. The models used in this effort thus far include the Mesoscale Atmospheric Simulation System (MASS), the Regional Atmospheric Modeling System (RAMS), and the National Centers for Environmental Prediction Eta Model ( Eta for short). The configuration of the MASS and RAMS is designed to run the models at very high spatial resolution and incorporate local data to resolve fine-scale weather features. Model preprocessors were modified to incorporate surface, ship, buoy, and rawinsonde data as well as data from local wind towers, wind profilers, and conventional or Doppler radars. The overall evaluation of the MASS, Eta, and RAMS was designed to assess the utility of these mesoscale models for satisfying the weather-forecasting needs of the U.S. space program. The evaluation methodology includes

  11. Mesoscale constitutive modeling of magnetic dispersions.

    PubMed

    Bhandar, Anand S; Wiest, John M

    2003-01-15

    A constitutive model for dispersions of acicular magnetic particles has been developed by modeling the particles as rigid dumbbells dispersed in a solvent. The effects of Brownian motion, anisotropic hydrodynamic drag, a steric force in the form of the Maier-Saupe potential, and, most importantly, a mean-field magnetic potential are included in the model. The development is similar to previous models for liquid-crystalline polymers. The model predicts multiple orientational states for the dispersion, and this phase behavior is described in terms of an orientational order parameter S and an average alignment parameter J; the latter is introduced because the magnetic particles have distinguishable direction due to polarity. A transition from isotropic to nematic phases at equilibrium is predicted. Multiple nematic phases-both prolate and oblate-are predicted in the presence of steady shear flow and external magnetic field parallel to the flow. The effect of increasing magnetic interparticle interactions and particle concentration is also presented. Comparisons with experimental data for the steady shear viscosity show very good agreement. PMID:16256493

  12. Mesoscale Modelling of Westafrican Precipitation In Impetus Westafrica

    NASA Astrophysics Data System (ADS)

    Born, K.; Bachner, S.; Haase, G.; Hübener, H.; Paeth, H.; Sogalla, M.

    The objective of the IMPETUS Westafricaproject is the research on water availability, water use and management and future impacts of expected climate changes on the socio-economic development in two critical regions of Westafrica: On the northern side of the Sahara in the catchment of the Qued Drâa in Morocco, south of the Sahara and Sahel in the catchment of the river Ouémé in Benin. Precipitation is the most important input to the hydrological cycle in these regions. For any hydrologic or economic modeling we need spatially distributed precipitation fields as accurate as possible. Therefore, precipitation modeling is one scope for the meteorologists participating in IMPETUS. For detailed studies on the influence of land use changes on soil hydrology and plant growth, the spatial scale of used models should be as small as possible. Therefore, the use of mesoscale models for regional climate modelling is tested and further developped. Since causes of rainfall variability are multiscale phenomena--teleconnections with ENSO and NAO steer the rainfall variability as well as local changes like deforestation--a hierachy of models, from the global scale down to the Meso- /Micro- scale, was set up to study processes affecting rainfall variability in the regions of interest. This model chain is described in some detail, first results and fu- ture aims of research activities in the area of mesoscale modeling are shown.

  13. DEVELOPMENT OF A LAND-SURFACE MODEL PART I: APPLICATION IN A MESOSCALE METEOROLOGY MODEL

    EPA Science Inventory

    Parameterization of land-surface processes and consideration of surface inhomogeneities are very important to mesoscale meteorological modeling applications, especially those that provide information for air quality modeling. To provide crucial, reliable information on the diurn...

  14. An application of an efficient non-hydrostatic mesoscale model

    NASA Astrophysics Data System (ADS)

    Flassak, Th.; Moussiopoulos, N.

    1987-12-01

    This paper deals with a non-hydrostatic mesoscale model that achieves full vectorization on computers like the CYBER 205. The model formulation ensures the conservation of all fluxes and takes into account the terrain inhomogeneities by the aid of suitable transformations. The diagnostic equation for the pressure change is solved using a very efficient vectorized elliptic solver. By imposing appropriate boundary conditions no additional precautions at the boundaries are necessary to achieve meaningful results. As an application, the steady-state inviscid flow over a single mountain is simulated.

  15. Hydrodynamic modeling of Singapore's coastal waters: Nesting and model accuracy

    NASA Astrophysics Data System (ADS)

    Hasan, G. M. Jahid; van Maren, Dirk Sebastiaan; Ooi, Seng Keat

    2016-01-01

    The tidal variation in Singapore's coastal waters is influenced by large-scale, complex tidal dynamics (by interaction of the Indian Ocean and the South China Sea) as well as monsoon-driven low frequency variations, requiring a model with large spatial coverage. Close to the shores, the complex topography, influenced by headlands and small islands, requires a high resolution model to simulate tidal dynamics. This can be achieved through direct nesting or multi-scale nesting, involving multiple model grids. In this paper, we investigate the effect of grid resolution and multi-scale nesting on the tidal dynamics in Singapore's coastal waters, by comparing model results with observations using different statistical techniques. The results reveal that the intermediate-scale model is generally sufficiently accurate (equal to or better than the most refined model), but also that the most refined model is only more accurate when nested in the intermediate scale model (requiring multi-scale nesting). This latter is the result of the complex tidal dynamics around Singapore, where the dominantly diurnal tidal currents are decoupled from the semi-diurnal water level variations. Furthermore, different techniques to quantify model accuracy (harmonic analysis, basic statistics and more complex statistics) are inconsistent in determining which model is more accurate.

  16. Transitioning a unidirectional composite computer model from mesoscale to continuum

    NASA Astrophysics Data System (ADS)

    Chocron, Sidney; Zaera, Ramón; Walker, James; Brill, Alon; Kositski, Roman; Havazelet, Doron; Heisserer, Ulrich; van der Werff, Harm

    2015-09-01

    Ballistic impact on composites has been a challenging problem as seen in the abundant literature about the subject. Continuum models usually cannot properly predict deflection history on the back of the target while at the same time giving reasonable ballistic limits. According to the authors the main reason is that, while continuum models are very good at reproducing the elastic characteristics of the laminate, the models do not capture the behaviour of the "failed" material. A "failed" composite can still be very effective in stopping a projectile, because it can behave very similar to a dry woven fabric. The failure aspect is much easier to capture realistically with a mesoscale model. These models explicitly contain yarns and matrix allowing the matrix to fail while the yarns stay intact and continue to offer resistance to the projectile. This paper summarizes the work performed by the authors on the computationally expensive mesoscale models and, using them as benchmark computations, describes the first steps towards obtaining more computationally effective models that still keep the right physics of the impact.

  17. Mesoscale modeling of polyelectrolyte brushes with salt.

    PubMed

    Ibergay, Cyrille; Malfreyt, Patrice; Tildesley, Dominic J

    2010-06-01

    We report dissipative particle dynamics (DPD) simulations of a polyelectrolyte brush under athermal solvent conditions. The electrostatic interactions are calculated using the particle-particle particle-mesh (PPPM) method with charges distributed over the particles. The polymer beads, counterions, co-ions, and solvent particles are modeled explicitly. The DPD simulations show a dependence of the brush height on the grafting density and the charge fraction that is typical of the nonlinear osmotic brush regime. We report the effect of the addition of salt on the structural properties of the brush. In the case of a polyelectrolyte brush with a high surface coverage, the simulations reproduce the transition between the nonlinear osmotic brush regime where the thickness of the brush is independent of the salt concentration and the salted regime where the brush height decreases weakly with the salt concentration. PMID:20455593

  18. Evaluation of an Urban Canopy Parameterization in a Mesoscale Model

    SciTech Connect

    Chin, H S; Leach, M J; Sugiyama, G A; Leone, Jr., J M; Walker, H; Nasstrom, J; Brown, M J

    2004-03-18

    A modified urban canopy parameterization (UCP) is developed and evaluated in a three-dimensional mesoscale model to assess the urban impact on surface and lower atmospheric properties. This parameterization accounts for the effects of building drag, turbulent production, radiation balance, anthropogenic heating, and building rooftop heating/cooling. USGS land-use data are also utilized to derive urban infrastructure and urban surface properties needed for driving the UCP. An intensive observational period with clear-sky, strong ambient wind and drainage flow, and the absence of land-lake breeze over the Salt Lake Valley, occurring on 25-26 October 2000, is selected for this study. A series of sensitivity experiments are performed to gain understanding of the urban impact in the mesoscale model. Results indicate that within the selected urban environment, urban surface characteristics and anthropogenic heating play little role in the formation of the modeled nocturnal urban boundary layer. The rooftop effect appears to be the main contributor to this urban boundary layer. Sensitivity experiments also show that for this weak urban heat island case, the model horizontal grid resolution is important in simulating the elevated inversion layer. The root mean square errors of the predicted wind and temperature with respect to surface station measurements exhibit substantially larger discrepancies at the urban locations than the rural counterparts. However, the close agreement of modeled tracer concentration with observations fairly justifies the modeled urban impact on the wind direction shift and wind drag effects.

  19. Validation of an Urban Parameterization in a Mesoscale Model

    SciTech Connect

    Leach, M.J.; Chin, H.

    2001-07-19

    The Atmospheric Science Division at Lawrence Livermore National Laboratory uses the Naval Research Laboratory's Couple Ocean-Atmosphere Mesoscale Prediction System (COAMPS) for both operations and research. COAMPS is a non-hydrostatic model, designed as a multi-scale simulation system ranging from synoptic down to meso, storm and local terrain scales. As model resolution increases, the forcing due to small-scale complex terrain features including urban structures and surfaces, intensifies. An urban parameterization has been added to the Naval Research Laboratory's mesoscale model, COAMPS. The parameterization attempts to incorporate the effects of buildings and urban surfaces without explicitly resolving them, and includes modeling the mean flow to turbulence energy exchange, radiative transfer, the surface energy budget, and the addition of anthropogenic heat. The Chemical and Biological National Security Program's (CBNP) URBAN field experiment was designed to collect data to validate numerical models over a range of length and time scales. The experiment was conducted in Salt Lake City in October 2000. The scales ranged from circulation around single buildings to flow in the entire Salt Lake basin. Data from the field experiment includes tracer data as well as observations of mean and turbulence atmospheric parameters. Wind and turbulence predictions from COAMPS are used to drive a Lagrangian particle model, the Livermore Operational Dispersion Integrator (LODI). Simulations with COAMPS and LODI are used to test the sensitivity to the urban parameterization. Data from the field experiment, including the tracer data and the atmospheric parameters, are also used to validate the urban parameterization.

  20. Optogenetic stimulation of a meso-scale human cortical model

    NASA Astrophysics Data System (ADS)

    Selvaraj, Prashanth; Szeri, Andrew; Sleigh, Jamie; Kirsch, Heidi

    2015-03-01

    Neurological phenomena like sleep and seizures depend not only on the activity of individual neurons, but on the dynamics of neuron populations as well. Meso-scale models of cortical activity provide a means to study neural dynamics at the level of neuron populations. Additionally, they offer a safe and economical way to test the effects and efficacy of stimulation techniques on the dynamics of the cortex. Here, we use a physiologically relevant meso-scale model of the cortex to study the hypersynchronous activity of neuron populations during epileptic seizures. The model consists of a set of stochastic, highly non-linear partial differential equations. Next, we use optogenetic stimulation to control seizures in a hyperexcited cortex, and to induce seizures in a normally functioning cortex. The high spatial and temporal resolution this method offers makes a strong case for the use of optogenetics in treating meso scale cortical disorders such as epileptic seizures. We use bifurcation analysis to investigate the effect of optogenetic stimulation in the meso scale model, and its efficacy in suppressing the non-linear dynamics of seizures.

  1. Validation of a new Mesoscale Model for MARS .

    NASA Astrophysics Data System (ADS)

    De Sanctis, K.; Ferretti, R.; Forget, F.; Fiorenza, C.; Visconti, G.

    The study of Mars planet is very important because of the several similarities with the Earth. For the understanding of the dynamical processes which drive the martian atmosphere, a new Martian Mesoscale Model (MARS-MM5) is presented. The new model is based on the Pennsylvania State University (PSU)/National Centre for Atmosphere Research (NCAR) Mesoscale Model Version 5 \\citep{duh,gre}. MARS-MM5 has been adapted to Mars using soil characteristics and topography obtained by Mars Orbital Laser Altimeter (MOLA). Different cases, depending from data availability and corresponding to the equatorial region of Mars, have been selected for multiple MARS-MM5 simulations. To validate the different developments Mars Climate Database (MCD) and TES observations have been employed: MCD version 4.0 has been created on the basis of multi annual integration of Mars GCM output. The Thermal Emission Spectromter observations (TES) detected during Mars Global Surveyor (MGS) mission are used in terms of temperature. The new, and most important, aspect of this work is the direct validation of the newly generated MARS-MM5 in terms of three-dimensional observations. The comparison between MARS-MM5 and GCM horizontal and vertical temperature profiles shows a good agreement; moreover, a good agreement is also found between TES observations and MARS-MM5.

  2. Evaluation of cloud prediction and determination of critical relative humidity for a mesoscale numerical weather prediction model

    SciTech Connect

    Seaman, N.L.; Guo, Z.; Ackerman, T.P.

    1996-04-01

    Predictions of cloud occurrence and vertical location from the Pennsylvannia State University/National Center for Atmospheric Research nonhydrostatic mesoscale model (MM5) were evaluated statistically using cloud observations obtained at Coffeyville, Kansas, as part of the Second International satellite Cloud Climatology Project Regional Experiment campaign. Seventeen cases were selected for simulation during a November-December 1991 field study. MM5 was used to produce two sets of 36-km simulations, one with and one without four-dimensional data assimilation (FDDA), and a set of 12-km simulations without FDDA, but nested within the 36-km FDDA runs.

  3. Use of observational and model-derived fields and regime model output statistics in mesoscale forecasting

    NASA Technical Reports Server (NTRS)

    Forbes, G. S.; Pielke, R. A.

    1985-01-01

    Various empirical and statistical weather-forecasting studies which utilize stratification by weather regime are described. Objective classification was used to determine weather regime in some studies. In other cases the weather pattern was determined on the basis of a parameter representing the physical and dynamical processes relevant to the anticipated mesoscale phenomena, such as low level moisture convergence and convective precipitation, or the Froude number and the occurrence of cold-air damming. For mesoscale phenomena already in existence, new forecasting techniques were developed. The use of cloud models in operational forecasting is discussed. Models to calculate the spatial scales of forcings and resultant response for mesoscale systems are presented. The use of these models to represent the climatologically most prevalent systems, and to perform case-by-case simulations is reviewed. Operational implementation of mesoscale data into weather forecasts, using both actual simulation output and method-output statistics is discussed.

  4. Mesoscale Modeling of Impact Compaction of Primitive Solar System Solids

    NASA Astrophysics Data System (ADS)

    Davison, Thomas M.; Collins, Gareth S.; Bland, Philip A.

    2016-04-01

    We have developed a method for simulating the mesoscale compaction of early solar system solids in low-velocity impact events using the iSALE shock physics code. Chondrules are represented by non-porous disks, placed within a porous matrix. By simulating impacts into bimodal mixtures over a wide range of parameter space (including the chondrule-to-matrix ratio, the matrix porosity and composition, and the impact velocity), we have shown how each of these parameters influences the shock processing of heterogeneous materials. The temperature after shock processing shows a strong dichotomy: matrix temperatures are elevated much higher than the chondrules, which remain largely cold. Chondrules can protect some matrix from shock compaction, with shadow regions in the lee side of chondrules exhibiting higher porosity that elsewhere in the matrix. Using the results from this mesoscale modeling, we show how the ɛ - α porous-compaction model parameters depend on initial bulk porosity. We also show that the timescale for the temperature dichotomy to equilibrate is highly dependent on the porosity of the matrix after the shock, and will be on the order of seconds for matrix porosities of less than 0.1, and on the order of tens to hundreds of seconds for matrix porosities of ˜0.3-0.5. Finally, we have shown that the composition of the post-shock material is able to match the bulk porosity and chondrule-to-matrix ratios of meteorite groups such as carbonaceous chondrites and unequilibrated ordinary chondrites.

  5. Anisotropic mesoscale eddy transport in ocean general circulation models

    NASA Astrophysics Data System (ADS)

    Reckinger, Scott; Fox-Kemper, Baylor; Bachman, Scott; Bryan, Frank; Dennis, John; Danabasoglu, Gokhan

    2014-11-01

    In modern climate models, the effects of oceanic mesoscale eddies are introduced by relating subgrid eddy fluxes to the resolved gradients of buoyancy or other tracers, where the proportionality is, in general, governed by an eddy transport tensor. The symmetric part of the tensor, which represents the diffusive effects of mesoscale eddies, is universally treated isotropically. However, the diffusive processes that the parameterization approximates, such as shear dispersion and potential vorticity barriers, typically have strongly anisotropic characteristics. Generalizing the eddy diffusivity tensor for anisotropy extends the number of parameters from one to three: major diffusivity, minor diffusivity, and alignment. The Community Earth System Model (CESM) with the anisotropic eddy parameterization is used to test various choices for the parameters, which are motivated by observations and the eddy transport tensor diagnosed from high resolution simulations. Simply setting the ratio of major to minor diffusivities to a value of five globally, while aligning the major axis along the flow direction, improves biogeochemical tracer ventilation and reduces temperature and salinity biases. These effects can be improved by parameterizing the oceanic anisotropic transport mechanisms.

  6. A hierarchical nest survival model integrating incomplete temporally varying covariates

    PubMed Central

    Converse, Sarah J; Royle, J Andrew; Adler, Peter H; Urbanek, Richard P; Barzen, Jeb A

    2013-01-01

    Nest success is a critical determinant of the dynamics of avian populations, and nest survival modeling has played a key role in advancing avian ecology and management. Beginning with the development of daily nest survival models, and proceeding through subsequent extensions, the capacity for modeling the effects of hypothesized factors on nest survival has expanded greatly. We extend nest survival models further by introducing an approach to deal with incompletely observed, temporally varying covariates using a hierarchical model. Hierarchical modeling offers a way to separate process and observational components of demographic models to obtain estimates of the parameters of primary interest, and to evaluate structural effects of ecological and management interest. We built a hierarchical model for daily nest survival to analyze nest data from reintroduced whooping cranes (Grus americana) in the Eastern Migratory Population. This reintroduction effort has been beset by poor reproduction, apparently due primarily to nest abandonment by breeding birds. We used the model to assess support for the hypothesis that nest abandonment is caused by harassment from biting insects. We obtained indices of blood-feeding insect populations based on the spatially interpolated counts of insects captured in carbon dioxide traps. However, insect trapping was not conducted daily, and so we had incomplete information on a temporally variable covariate of interest. We therefore supplemented our nest survival model with a parallel model for estimating the values of the missing insect covariates. We used Bayesian model selection to identify the best predictors of daily nest survival. Our results suggest that the black fly Simulium annulus may be negatively affecting nest survival of reintroduced whooping cranes, with decreasing nest survival as abundance of S. annulus increases. The modeling framework we have developed will be applied in the future to a larger data set to evaluate the

  7. A hierarchical nest survival model integrating incomplete temporally varying covariates

    USGS Publications Warehouse

    Converse, Sarah J.; Royle, J. Andrew; Adler, Peter H.; Urbanek, Richard P.; Barzan, Jeb A.

    2013-01-01

    Nest success is a critical determinant of the dynamics of avian populations, and nest survival modeling has played a key role in advancing avian ecology and management. Beginning with the development of daily nest survival models, and proceeding through subsequent extensions, the capacity for modeling the effects of hypothesized factors on nest survival has expanded greatly. We extend nest survival models further by introducing an approach to deal with incompletely observed, temporally varying covariates using a hierarchical model. Hierarchical modeling offers a way to separate process and observational components of demographic models to obtain estimates of the parameters of primary interest, and to evaluate structural effects of ecological and management interest. We built a hierarchical model for daily nest survival to analyze nest data from reintroduced whooping cranes (Grus americana) in the Eastern Migratory Population. This reintroduction effort has been beset by poor reproduction, apparently due primarily to nest abandonment by breeding birds. We used the model to assess support for the hypothesis that nest abandonment is caused by harassment from biting insects. We obtained indices of blood-feeding insect populations based on the spatially interpolated counts of insects captured in carbon dioxide traps. However, insect trapping was not conducted daily, and so we had incomplete information on a temporally variable covariate of interest. We therefore supplemented our nest survival model with a parallel model for estimating the values of the missing insect covariates. We used Bayesian model selection to identify the best predictors of daily nest survival. Our results suggest that the black fly Simulium annulus may be negatively affecting nest survival of reintroduced whooping cranes, with decreasing nest survival as abundance of S. annulus increases. The modeling framework we have developed will be applied in the future to a larger data set to evaluate the

  8. A hierarchical nest survival model integrating incomplete temporally varying covariates.

    PubMed

    Converse, Sarah J; Royle, J Andrew; Adler, Peter H; Urbanek, Richard P; Barzen, Jeb A

    2013-11-01

    Nest success is a critical determinant of the dynamics of avian populations, and nest survival modeling has played a key role in advancing avian ecology and management. Beginning with the development of daily nest survival models, and proceeding through subsequent extensions, the capacity for modeling the effects of hypothesized factors on nest survival has expanded greatly. We extend nest survival models further by introducing an approach to deal with incompletely observed, temporally varying covariates using a hierarchical model. Hierarchical modeling offers a way to separate process and observational components of demographic models to obtain estimates of the parameters of primary interest, and to evaluate structural effects of ecological and management interest. We built a hierarchical model for daily nest survival to analyze nest data from reintroduced whooping cranes (Grus americana) in the Eastern Migratory Population. This reintroduction effort has been beset by poor reproduction, apparently due primarily to nest abandonment by breeding birds. We used the model to assess support for the hypothesis that nest abandonment is caused by harassment from biting insects. We obtained indices of blood-feeding insect populations based on the spatially interpolated counts of insects captured in carbon dioxide traps. However, insect trapping was not conducted daily, and so we had incomplete information on a temporally variable covariate of interest. We therefore supplemented our nest survival model with a parallel model for estimating the values of the missing insect covariates. We used Bayesian model selection to identify the best predictors of daily nest survival. Our results suggest that the black fly Simulium annulus may be negatively affecting nest survival of reintroduced whooping cranes, with decreasing nest survival as abundance of S. annulus increases. The modeling framework we have developed will be applied in the future to a larger data set to evaluate the

  9. Modeling Mesoscale Eddies in the North Atlantic Ocean

    NASA Technical Reports Server (NTRS)

    Chao, Yi

    1999-01-01

    Ocean modeling plays an important role in understanding the current climatic conditions and predicting the future climate change. Modeling the ocean at eddy-permitting and/or eddy resolving resolutions (1/3 degree or higher) has a two-fold objective. One part is to represent the ocean as realistically as possible, because mesoscale eddies have an impact on the large-scale circulation. The second objective is to learn how to represent effects of mesoscale eddies without explicitly resolving them. This is particularly important for climate models which cannot be run at eddy-resolving resolutions because of the computational constraints. At JPL, a 1/6 degree latitude by 1/6 degree longitude with 37 vertical levels Atlantic Ocean model has been developed. The model is based on the Parallel Ocean Program (POP) developed at Los Alamos National Laboratory (LANL). Using the 256-processor Cray T3D, we have conducted a 40-year integration of this Atlantic eddy-resolving ocean model. A regional analysis demonstrate that many observed features associated with the Caribbean Sea eddies can be realistically simulated by this model. Analysis of this Atlantic eddy-resolving ocean model further suggests that these Caribbean Sea eddies are connected with eddies formed outside the Caribbean Sea at the confluence of the North Brazil Current (NBC) and the North Equatorial Countercurrent. The diagram of the model simulated surface current shows that the Caribbean eddies ultimately originate in the NBC retroflection region, traveling more than a year from the North Brazil coast through the Lesser Antilles into the Caribbean Sea and eventually into the Gulf of Mexico. Additional information is contained in the original.

  10. Three-dimensional parabolic equation modeling of mesoscale eddy deflection.

    PubMed

    Heaney, Kevin D; Campbell, Richard L

    2016-02-01

    The impact of mesoscale oceanography, including ocean fronts and eddies, on global scale low-frequency acoustics is examined using a fully three-dimensional parabolic equation model. The narrowband acoustic signal, for frequencies from 2 to 16 Hz, is simulated from a seismic event on the Kerguellen Plateau in the South Indian Ocean to an array of receivers south of Ascension Island in the South Atlantic, a distance of 9100 km. The path was chosen for its relevance to seismic detections from the HA10 Ascension Island station of the International Monitoring System, for its lack of bathymetric interaction, and for the dynamic oceanography encountered as the sound passes the Cape of Good Hope. The acoustic field was propagated through two years (1992 and 1993) of the eddy-permitting ocean state estimation ECCO2 (Estimating the Circulation and Climate of the Ocean, Phase II) system. The range of deflection of the back-azimuth was 1.8° with a root-mean-square of 0.34°. The refraction due to mesoscale oceanography could therefore have significant impacts upon localization of distant low-frequency sources, such as seismic or nuclear test events. PMID:26936572

  11. High-frequency Environmental Tracer Data to Improve our Knowledge of Hydrological Functioning in Nested Mesoscale Catchments

    NASA Astrophysics Data System (ADS)

    Tetzlaff, D.; Waldron, S.; Brewer, M. J.; Soulsby, C.

    2006-12-01

    High resolution (15 minute) continuous environmental tracer data (conductivity, pH and derived Gran alkalinity,) were used to investigate the hydrological functioning of the 233km2 Feugh catchment in NE Scotland and two of its nested sub-catchments (42km2 and 1km2). The continuous data indicated detailed and subtle changes in stream chemistry. Diurnal variation in alkalinity and flow were observed under low flow conditions, attributed to instream respiration and riparian evapotranspiration respectively. At high flows, abrupt threshold behaviour was evident during storm events as hydrological sources in the acidic surface horizons of the catchment soils replace groundwater as the dominant source of runoff. Using Gran alkalinity to define end-member compositions, chemically-based hydrograph separations revealed that as catchment scale increased, groundwater contributions to annual runoff increased from 53 ± 11 %, to 66 ± 6 % , to 70 ± 11%. Mean residence times were estimated from weekly δ 18O data. Uncertainty increased from 1.3-4.7 months to 2.4-10.6 months to 2.5-11.1 months. The use of continuous tracer data increased the sophistication of our conceptual model of catchment processes: increasing dominance of responsive peaty soils leads to more saturation overland flow, increased flashiness of runoff, reduced groundwater recharge, reduced MRTs and more marked diurnal variations in flow, which drive concomitant difference in hydrochemistry.

  12. Mesoscale constitutive modeling of non-crystallizing filled elastomers

    NASA Astrophysics Data System (ADS)

    Harish, Ajay B.; Wriggers, Peter; Jungk, Juliane; Hojdis, Nils; Recker, Carla

    2016-04-01

    Elastomers are exceptional materials owing to their ability to undergo large deformations before failure. However, due to their very low stiffness, they are not always suitable for industrial applications. Addition of filler particles provides reinforcing effects and thus enhances the material properties that render them more versatile for applications like tyres etc. However, deformation behavior of filled polymers is accompanied by several nonlinear effects like Mullins and Payne effect. To this day, the physical and chemical changes resulting in such nonlinear effect remain an active area of research. In this work, we develop a heterogeneous (or multiphase) constitutive model at the mesoscale explicitly considering filler particle aggregates, elastomeric matrix and their mechanical interaction through an approximate interface layer. The developed constitutive model is used to demonstrate cluster breakage, also, as one of the possible sources for Mullins effect observed in non-crystallizing filled elastomers.

  13. Mesoscale Eddy Parameterization in an Idealized Primitive Equations Model

    NASA Astrophysics Data System (ADS)

    Anstey, J.; Zanna, L.

    2014-12-01

    Large-scale ocean currents such as the Gulf Stream and Kuroshio Extension are strongly influenced by mesoscale eddies, which have spatial scales of order 10-100 km. The effects of these eddies are poorly represented in many state-of-the-art ocean general circulation models (GCMs) due to the inadequate spatial resolution of these models. In this study we examine the response of the large-scale ocean circulation to the rectified effects of eddy forcing - i.e., the role played by surface-intensified mesoscale eddies in sustaining and modulating an eastward jet that separates from an intense western boundary current (WBC). For this purpose a primitive equations ocean model (the MITgcm) in an idealized wind-forced double-gyre configuration is integrated at eddy-resolving resolution to reach a forced-dissipative equilibrium state that captures the essential dynamics of WBC-extension jets. The rectified eddy forcing is diagnosed as a stochastic function of the large-scale state, this being characterized by the manner in which potential vorticity (PV) contours become deformed. Specifically, a stochastic function based on the Laplacian of the material rate of change of PV is examined in order to compare the primitive equations results with those of a quasi-geostrophic model in which this function has shown some utility as a parameterization of eddy effects (Porta Mana and Zanna, 2014). The key question is whether an eddy parameterization based on quasi-geostrophic scaling is able to carry over to a system in which this scaling is not imposed (i.e. the primitive equations), in which unbalanced motions occur.

  14. Initialization of a mesoscale model for April 10, 1979, using alternative data sources

    NASA Technical Reports Server (NTRS)

    Kalb, M. W.

    1984-01-01

    A 35 km grid limited area mesoscale model was initialized with high density SESAME radiosonde data and high density TIROS-N satellite temperature profiles for April 10, 1979. These data sources were used individually and with low level wind fields constructed from surface wind observations. The primary objective was to examine the use of satellite temperature data for initializing a mesoscale model by comparing the forecast results with similar experiments employing radiosonde data. The impact of observed low level winds on the model forecasts was also investigated with experiments varying the method of insertion. All forecasts were compared with each other and with mesoscale observations for precipitation, mass and wind structure. Several forecasts produced convective precipitation systems with characteristics satisfying criteria for a mesoscale convective complex. High density satellite temperature data and balanced winds can be used in a mesoscale model to produce forecasts which verify favorably with observations.

  15. A spatial model of waterfowl nest site selection in grassland nesting cover

    NASA Astrophysics Data System (ADS)

    Pool, Duane Bruce

    Ducks Unlimited's (DU) mission statement is focused on providing for the annual lifecycle needs of migratory waterfowl. The largest impacts to the success and numbers of continental populations are determined by their activities on the breeding grounds. To model and therefore manage habitats and landscapes for ducks (Anas and Aythya spp.) it is necessary to understand several characteristics of their behavior. This research builds a model of nest site selection from nest probability based on remotely sensed data, presence data and minimum threshold theory. The methods used are applicable to other sensor platforms as well as other target species or phenomenon. Using data compression techniques, logistic regression, and spatial statistical functions (Ripley's k-function, a global k-function, and Multiple Response Permutation Procedure) we tested the observed point patterns and developed a point process model to predict nesting patterns. The application of this type of fine resolution database, validated by empirical data, will be more powerful than either classified remote sensing data or field level nest demographic data alone. In the largest of the five study sites, which was also the site with the greatest number of observations, the pattern of nests were significantly different from Poisson. The model developed to fit these data was tested using the other sites and the observed data on the other four sites were not shown to be significantly different from the model. The tests for spatial association showed some evidence negative association between Blue-winged Teal and Gadwall as well as between successful and unsuccessful nest. There is some evidence that a process of natural selection may exist and the future studies should be designed with this in mind. These data will be used as a baseline for future habitat manipulation and controlled experiments on the DU Goebel Ranch complex. The results of this and future studies will be used as the basis for DU strategic

  16. The Challenge of Forecasting the Onset and Development of Radiation Fog Using Mesoscale Atmospheric Models

    NASA Astrophysics Data System (ADS)

    Steeneveld, G. J.; Ronda, R. J.; Holtslag, A. A. M.

    2015-02-01

    The numerical weather prediction of radiation fog is challenging, as many models typically show large biases for the timing of the onset and dispersal of the fog, as well as for its depth and liquid water content. To understand the role of physical processes, i.e. turbulence, radiation, land-surface coupling, and microphysics, we evaluate the HARMONIE and Weather Research and Forecasting (WRF) mesoscale models for two contrasting warm fog episodes at the relatively flat terrain around the Cabauw tower facility in the Netherlands. One case involves a radiation fog that arose in calm anticyclonic conditions, and the second is a radiation fog that developed just after a cold front passage. The WRF model represents the radiation fog well, while the HARMONIE model forecasts a stratus lowering fog layer in the first case and hardly any fog in the second case. Permutations of parametrization schemes for boundary-layer mixing, radiation and microphysics, each for two levels of complexity, have been evaluated within the WRF model. It appears that the boundary-layer formulation is critical for forecasting the fog onset, while for fog dispersal the choice of the microphysical scheme is a key element, where a double-moment scheme outperforms any of the single-moment schemes. Finally, the WRF model results appear to be relatively insensitive to horizontal grid spacing, but nesting deteriorates the modelled fog formation. Increasing the domain size leads to a more scattered character of the simulated fog. Model results with one-way or two-way nesting show approximately comparable results.

  17. Mesoscale Simulation Data for Initializing Fast-Time Wake Transport and Decay Models

    NASA Technical Reports Server (NTRS)

    Ahmad, Nashat N.; Proctor, Fred H.; Vanvalkenburg, Randal L.; Pruis, Mathew J.; LimonDuparcmeur, Fanny M.

    2012-01-01

    The fast-time wake transport and decay models require vertical profiles of crosswinds, potential temperature and the eddy dissipation rate as initial conditions. These inputs are normally obtained from various field sensors. In case of data-denied scenarios or operational use, these initial conditions can be provided by mesoscale model simulations. In this study, the vertical profiles of potential temperature from a mesoscale model were used as initial conditions for the fast-time wake models. The mesoscale model simulations were compared against available observations and the wake model predictions were compared with the Lidar measurements from three wake vortex field experiments.

  18. Observation Denial and Performance of a Local Mesoscale Model

    NASA Technical Reports Server (NTRS)

    Watson, Leela R.; Bauman, William H., III

    2009-01-01

    .Forecasters at the 45th Weather Squadron (45 WS) use observations from the Kennedy Space Center (KSC) and Cape Canaveral Air Force Station (CCAFS) wind tower network and the CCAFS (XMR) daily rawinsonde observations (RAOB) to issue and verify wind advisories and warnings for operations. These observations are also used by the National Weather Service (NWS) Spaceflight Meteorology Group (SMG) in Houston, Texas and the NWS Melbourne, Florida (NWS MLB) to initialize their locally-run mesoscale models. In addition, SMG uses these observations to support shuttle landings at the Shuttle Landing Facility (SLF). Due to impending budget cuts, some or all of the wind towers on the east-central Florida mainland and the XMR RAOBs may be eliminated. The locations of the mainland towers and XMR RAOB site are shown in Figure 1. The loss of these data may impact the forecast capability of the 45 WS, SMG and NWS MLB.

  19. Numerical Simulation of Chennai Heavy Rainfall Using MM5 Mesoscale Model with Different Cumulus Parameterization Schemes

    NASA Astrophysics Data System (ADS)

    Litta, A. J.; Chakrapani, B.; Mohankumar, K.

    2007-07-01

    Heavy rainfall events become significant in human affairs when they are combined with hydrological elements. The problem of forecasting heavy precipitation is especially difficult since it involves making a quantitative precipitation forecast, a problem well recognized as challenging. Chennai (13.04°N and 80.17°E) faced incessant and heavy rain about 27 cm in 24 hours up to 8.30 a.m on 27th October 2005 completely threw life out of gear. This torrential rain caused by deep depression which lay 150km east of Chennai city in Bay of Bengal intensified and moved west north-west direction and crossed north Tamil Nadu and south Andhra Pradesh coast on 28th morning. In the present study, we investigate the predictability of the MM5 mesoscale model using different cumulus parameterization schemes for the heavy rainfall event over Chennai. MM5 Version 3.7 (PSU/NCAR) is run with two-way triply nested grids using Lambert Conformal Coordinates (LCC) with a nest ratio of 3:1 and 23 vertical layers. Grid sizes of 45, 15 and 5 km are used for domains 1, 2 and 3 respectively. The cumulus parameterization schemes used in this study are Anthes-Kuo scheme (AK), the Betts-Miller scheme (BM), the Grell scheme (GR) and the Kain-Fritsch scheme (KF). The present study shows that the prediction of heavy rainfall is sensitive to cumulus parameterization schemes. In the time series of rainfall, Grell scheme is in good agreement with observation. The ideal combination of the nesting domains, horizontal resolution and cloud parameterization is able to simulate the heavy rainfall event both qualitatively and quantitatively.

  20. Mesoscale Modeling of Impact Compaction of Primitive Solar System Solids

    NASA Astrophysics Data System (ADS)

    Davison, Thomas M.; Collins, Gareth S.; Bland, Philip A.

    2016-04-01

    We have developed a method for simulating the mesoscale compaction of early solar system solids in low-velocity impact events using the iSALE shock physics code. Chondrules are represented by non-porous disks, placed within a porous matrix. By simulating impacts into bimodal mixtures over a wide range of parameter space (including the chondrule-to-matrix ratio, the matrix porosity and composition, and the impact velocity), we have shown how each of these parameters influences the shock processing of heterogeneous materials. The temperature after shock processing shows a strong dichotomy: matrix temperatures are elevated much higher than the chondrules, which remain largely cold. Chondrules can protect some matrix from shock compaction, with shadow regions in the lee side of chondrules exhibiting higher porosity that elsewhere in the matrix. Using the results from this mesoscale modeling, we show how the ε ‑ α porous-compaction model parameters depend on initial bulk porosity. We also show that the timescale for the temperature dichotomy to equilibrate is highly dependent on the porosity of the matrix after the shock, and will be on the order of seconds for matrix porosities of less than 0.1, and on the order of tens to hundreds of seconds for matrix porosities of ∼0.3–0.5. Finally, we have shown that the composition of the post-shock material is able to match the bulk porosity and chondrule-to-matrix ratios of meteorite groups such as carbonaceous chondrites and unequilibrated ordinary chondrites.

  1. Meteorological predictions for Mars 2020 Exploration Rover high-priority landing sites throug MRAMS Mesoscale Modeling

    NASA Astrophysics Data System (ADS)

    Pla-García, Jorge; Rafkin, Scot C. R.

    2015-04-01

    The Mars Regional Atmospheric Modeling System (MRAMS) is used to predict meteorological conditions that are likely to be encountered by the Mars 2020 Exploration Rover at several proposed landing sites during entry, descent, and landing (EDL). The meteorology during the EDL window at most of the sites is dynamic. The intense heating of the lower atmosphere drives intense thermals and mesoscale thermal circulations. Moderate mean winds, wind shear, turbulence, and vertical air currents associated with convection are present and potentially hazardous to EDL [1]. Nine areas with specific high-priority landing ellipses of the 2020 Rover, are investigated: NE Syrtis, Nili Fossae, Nili Fossae Carbonates, Jezero Crater Delta, Holden Crater, McLaughlin Crater, Southwest Melas Basin, Mawrth Vallis and East Margaritifer Chloride. MRAMS was applied to the landing site regions using nested grids with a spacing of 330 meters on the innermost grid that is centered over each landing site. MRAMS is ideally suited for this investigation; the model is explicitly designed to simulate Mars' atmospheric thermal circulations at the mesoscale and smaller with realistic, high-resolution surface properties [2, 3]. Horizontal wind speeds, both vertical profiles and vertical cross-sections wind speeds, are studied. For some landing sites simulations, two example configurations -including and not including Hellas basin in the mother domain- were generated, in order to study how the basin affects the innermost grids circulations. Afternoon circulations at all sites pose some risk entry, descent, and landing. Most of the atmospheric hazards are not evident in current observational data and general circulation model simulations and can only be ascertained through mesoscale modeling of the region. Decide where to go first and then design a system that can tolerate the environment would greatly minimize risk. References: [1] Rafkin, S. C. R., and T. I. Michaels (2003), J. Geophys. Res., 108(E12

  2. Systematic multiscale models for deep convection on mesoscales

    NASA Astrophysics Data System (ADS)

    Klein, Rupert; Majda, Andrew J.

    2006-11-01

    This paper builds on recent developments of a unified asymptotic approach to meteorological modeling [ZAMM, 80: 765 777, 2000, SIAM Proc. App. Math. 116, 227 289, 2004], which was used successfully in the development of Systematic multiscale models for the tropics in Majda and Klein [J. Atmosph. Sci. 60: 393 408, 2003] and Majda and Biello [PNAS, 101: 4736 4741, 2004]. Biello and Majda [J. Atmosph. Sci. 62: 1694 1720, 2005]. Here we account for typical bulk microphysics parameterizations of moist processes within this framework. The key steps are careful nondimensionalization of the bulk microphysics equations and the choice of appropriate distinguished limits for the various nondimensional small parameters that appear. We are then in a position to study scale interactions in the atmosphere involving moist physics. We demonstrate this by developing two systematic multiscale models that are motivated by our interest in mesoscale organized convection. The emphasis here is on multiple length scales but common time scales. The first of these models describes the short-time evolution of slender, deep convective hot towers with horizontal scale ~ 1 km interacting with the linearized momentum balance on length and time scales of (10 km/3 min). We expect this model to describe how convective inhibition may be overcome near the surface, how the onset of deep convection triggers convective-scale gravity waves, and that it will also yield new insight into how such local convective events may conspire to create larger-scale strong storms. The second model addresses the next larger range of length and time scales (10 km, 100 km, and 20 min) and exhibits mathematical features that are strongly reminiscent of mesoscale organized convection. In both cases, the asymptotic analysis reveals how the stiffness of condensation/evaporation processes induces highly nonlinear dynamics. Besides providing new theoretical insights, the derived models may also serve as a theoretical devices

  3. Numerical photochemical modeling over Madrid (Spain) mesoscale urban area

    NASA Astrophysics Data System (ADS)

    San Jose, Roberto; Ramirez-Montesinos, Arturo; Marcelo, Luis M.; Sanz, Miguel A.; Rodriguez, Luis M.

    1995-09-01

    Photochemical air quality models provide the most defensible method for relating future air quality to changes in emission, and hence are the foundation for determining the effectiveness of proposed control strategies. In this contribution, we will show results from different photochemical schemes under typical emission conditions for a summer day in the Madrid mesocsale urban area. We will show that complex numerical integrated urban mesoscale models are a powerful tool to predict the ozone levels on this area. The comparison of model simulations at different grid points show an acceptable preliminary behavior. The results presented in this paper are prepared for August 15th, 1991 and the predicted ozone values are compared with those measured at two stations of the Madrid city monitoring network. Results show that the shape is successfully predicted by using the NUFOMO (numerical photochemical model) model. Because of the computer limitations, we have limited the results to this case study. Further investigations will provide additional information to produce a statistical analysis of the results. However, preliminary results show that the NUFOMO model is able to reproduce the measured ozone values.

  4. Operational Assimilation of GOES Data into a Mesoscale Model

    NASA Technical Reports Server (NTRS)

    Lapenta, William; Suggs, Ron; McNider, Richard; Jedlovec, Gary; Dembek, Scott

    2000-01-01

    A technique has been developed for assimilating GOES-derived skin temperature tendencies and insolation into the surface energy budget equation of a mesoscale model so that the simulated rate of temperature change closely agrees with the satellite observations. A critical assumption of the technique is that the availability of moisture (either from the soil or vegetation) is the least known term in the model's surface energy budget. Therefore, the simulated latent heat flux, which is a function of surface moisture availability, is adjusted based upon differences between the modeled and satellite- observed skin temperature tendencies. An advantage of this technique is that satellite temperature tendencies are assimilated in an energetically consistent manner that avoids energy imbalances and surface stability problems that arise from direct assimilation of surface shelter temperatures. The fact that the rate of change of the satellite skin temperature is used rather than the absolute temperature means that sensor calibration is not as critical. The technique has been employed on a semi-operational basis at the Global Hydrology and Climate Center (GHCC) within the Penn State/National Center for Atmospheric Research (PSU/NCAR) Mesoscale Model (MM5) since 1 November 1998. We performed the assimilation on a model grid centered over the Southeastern US. In addition, a control run without assimilation was performed to provide insight into the performance of the assimilation technique. Bulk verification statistics (BIAS and RMSE) of surface air temperature and relative humidity of more than 250 case days has been performed to date. Results show that assimilation of the satellite data results reduces both the bias and RMSE for simulations of surface air temperature and relative humidity. We are working with forecasters at the National Weather Service Forecast Office located in Birmingham, AL to evaluate the impact of the assimilation on precipitation forecasts. In addition

  5. Performance of a Local Mesoscale Model with Data Denial

    NASA Technical Reports Server (NTRS)

    Watson, Leela; Baumann, William H., III

    2008-01-01

    Forecasters at the 45th Weather Squadron (45 WS) use observations from the Kennedy Space Center (KSC) and Cape Canaveral Air Force Station (CCAFS) wind tower network and daily rawinsonde observations (RAOB) to issue and verify wind advisories, watches, and warnings for operations. They are also used by the Spaceflight Meteorology Group and Melbourne, Florida National Weather Service to initialize locally run mesoscale models. Due to impending budget cuts, some or all of the mainland wind towers and RAOBs may be eliminated, The loss of these data may significantly impact the forecast capability of the 45 WS and SMG. The Applied Meteorology Unit (AMU) was tasked to conduct an objective independent modeling study to determine how important these observations are to the accuracy of the model output used by the forecasters as input to their forecasts. To accomplish this, the AMU performed a sensitivity study using the Weather Research and Forecasting (WRF) model run with and without KSC/CCAFS wind tower and CCAFS RAOB observations and assessed the accuracy of model forecasts by comparing them to the observations.

  6. LMD - SwRI Martian Mesoscale Models Intercomparison for ExoMars Landing Site Characterization

    NASA Astrophysics Data System (ADS)

    Bertrand, T.; Spiga, A.; Rafkin, S.; Colaitis, A.; Forget, F.; Millour, E.

    2013-09-01

    Martian mesoscale models realisticaly simulate Martian meteorology at finer scales (~10km) than Global Climate Models (GCM). This modelling is becoming a central source of insights and diagnostics for future exploration of Mars and is useful to provide best-guesses of atmospheric variations of temperature and wind at mesoscale level. In such context, Model intercomparisons are a fruitful way to evaluate and assess the obtained predictions.

  7. Analysis of Surface Heterogeneity Effects with Mesoscale Terrestrial Modeling Platforms

    NASA Astrophysics Data System (ADS)

    Simmer, C.

    2015-12-01

    An improved understanding of the full variability in the weather and climate system is crucial for reducing the uncertainty in weather forecasting and climate prediction, and to aid policy makers to develop adaptation and mitigation strategies. A yet unknown part of uncertainty in the predictions from the numerical models is caused by the negligence of non-resolved land surface heterogeneity and the sub-surface dynamics and their potential impact on the state of the atmosphere. At the same time, mesoscale numerical models using finer horizontal grid resolution [O(1)km] can suffer from inconsistencies and neglected scale-dependencies in ABL parameterizations and non-resolved effects of integrated surface-subsurface lateral flow at this scale. Our present knowledge suggests large-eddy-simulation (LES) as an eventual solution to overcome the inadequacy of the physical parameterizations in the atmosphere in this transition scale, yet we are constrained by the computational resources, memory management, big-data, when using LES for regional domains. For the present, there is a need for scale-aware parameterizations not only in the atmosphere but also in the land surface and subsurface model components. In this study, we use the recently developed Terrestrial Systems Modeling Platform (TerrSysMP) as a numerical tool to analyze the uncertainty in the simulation of surface exchange fluxes and boundary layer circulations at grid resolutions of the order of 1km, and explore the sensitivity of the atmospheric boundary layer evolution and convective rainfall processes on land surface heterogeneity.

  8. A Mesoscale Model of DNA and Its Renaturation

    PubMed Central

    Sambriski, E.J.; Schwartz, D.C.; de Pablo, J.J.

    2009-01-01

    A mesoscale model of DNA is presented (3SPN.1), extending the scheme previously developed by our group. Each nucleotide is mapped onto three interaction sites. Solvent is accounted for implicitly through a medium-effective dielectric constant and electrostatic interactions are treated at the level of Debye-Hückel theory. The force field includes a weak, solvent-induced attraction, which helps mediate the renaturation of DNA. Model parameterization is accomplished through replica exchange molecular dynamics simulations of short oligonucleotide sequences over a range of composition and chain length. The model describes the melting temperature of DNA as a function of composition as well as ionic strength, and is consistent with heat capacity profiles from experiments. The dependence of persistence length on ionic strength is also captured by the force field. The proposed model is used to examine the renaturation of DNA. It is found that a typical renaturation event occurs through a nucleation step, whereby an interplay between repulsive electrostatic interactions and colloidal-like attractions allows the system to undergo a series of rearrangements before complete molecular reassociation occurs. PMID:19254530

  9. Estimators for variance components in structured stair nesting models

    NASA Astrophysics Data System (ADS)

    Monteiro, Sandra; Fonseca, Miguel; Carvalho, Francisco

    2016-06-01

    The purpose of this paper is to present the estimation of the components of variance in structured stair nesting models. The relationship between the canonical variance components and the original ones, will be very important in obtaining that estimators.

  10. Simulation of elevated long-range plume transport using a mesoscale meteorological model

    NASA Astrophysics Data System (ADS)

    Boybeyi, Zafer; Raman, Sethu

    A three-dimensional mesoscale meteorological model was used to construct a modeling system in order to investigate atmospheric dispersion in mesoscale flow fields. The mesoscale model was first coupled to a three-dimensional Monte Carlo (Lagrangian particle) dispersion model, and then an Eulerian dispersion model was embedded into the mesoscale model. Both the Eulerian model and the Monte Carlo model are based on the wind and turbulence fields simulated by the mesoscale model. The modeling system was then applied to the Tennessee Plume Study field experiments on 23 August 1978. The field experiments were basically designed to provide information on the dynamics of plume transport over long distances, and primarily targeted the plume from the Cumberland steam plant. Wind and turbulence fields were first simulated by the mesoscale model. The transport and diffusion of pollutants from the Cumberland steam plant were then simulated by the dispersion models, using these wind and turbulence fields. The results demonstrated that the modeling system generally performed satisfactorily, reproducing the trajectory and spread of the Cumberland plume.

  11. Fog simulation using a mesoscale model in and around the Yodo River Basin, Japan.

    PubMed

    Hikari, Shimadera; Kundan, Lal Shrestha; Akira, Kondo; Akikazu, Kaga; Yoshio, Inoue

    2008-01-01

    In this study, fog simulations were conducted using the Fifth-Generation NCAR/Penn State Mesoscale Model (MM5) in and around the Yodo River Basin, Japan. The purpose is to investigate the MM5 performance of fog simulation for long-term periods. The simulations were performed for January, February, March, and July, 2005 with a coarse 3-km and a nested fine 1-km grid domains. Results of the simulations were compared with data from ten meteorological observatories, fog sampling site in Mt. Rokko, and visibility measurement sites along the Second Meishin Expressway. At the meteorological observatories, the MM5 predictions agreed well with the observed temperature and specific humidity. In the Mt. Rokko region, MM5 generally reproduced the occurrence of relatively thick fog events but tended to overestimate liquid water content (LWC) of fog (by factors of 2.2-3.3 in terms of monthly mean LWC). In the Second Meishin Expressway region, while MM5 identified the specific sites at which fog either frequently or seldom occurs, the model underestimated the monthly fog frequencies by factors of more than 1.5. Overall, MM5 reproduced the general trend of fog events, and the model performance may be improved by using more adequate land surface data and suitable physics options for our study. PMID:18814580

  12. A survey of nested grid techniques and their potential for use within the MASS weather prediction model

    NASA Technical Reports Server (NTRS)

    Koch, Steven E.; Mcqueen, Jeffery T.

    1987-01-01

    A survey of various one- and two-way interactive nested grid techniques used in hydrostatic numerical weather prediction models is presented and the advantages and disadvantages of each method are discussed. The techniques for specifying the lateral boundary conditions for each nested grid scheme are described in detail. Averaging and interpolation techniques used when applying the coarse mesh grid (CMG) and fine mesh grid (FMG) interface conditions during two-way nesting are discussed separately. The survey shows that errors are commonly generated at the boundary between the CMG and FMG due to boundary formulation or specification discrepancies. Methods used to control this noise include application of smoothers, enhanced diffusion, or damping-type time integration schemes to model variables. The results from this survey provide the information needed to decide which one-way and two-way nested grid schemes merit future testing with the Mesoscale Atmospheric Simulation System (MASS) model. An analytically specified baroclinic wave will be used to conduct systematic tests of the chosen schemes since this will allow for objective determination of the interfacial noise in the kind of meteorological setting for which MASS is designed. Sample diagnostic plots from initial tests using the analytic wave are presented to illustrate how the model-generated noise is ascertained. These plots will be used to compare the accuracy of the various nesting schemes when incorporated into the MASS model.

  13. High resolution topography and land cover databases for wind resource assessment using mesoscale models

    NASA Astrophysics Data System (ADS)

    Barranger, Nicolas; Stathopoulos, Christos; Kallos, Georges

    2013-04-01

    . Following, the implementation of all databases, a high resolution simulation is performed over the complex terrain area of Northern Spain. The results are compared with meteorological station in the Navarra region and tall masts available on site. Using two way nesting techniques, the model is simultaneously resolving the synoptic forcing over Spanish Peninsula, mesoscale features over Navarra Region and microscale flow pattern passing around the Alaiz Mountain. To do so, multiple grids nests are set up in which the resolution varies gradually from the order of 10km to 100m. The time step decreases from twenty seconds to tens of milliseconds according to the Courant Friedrichs Lewy condition. The model that features Message Passing Interface is run using 64 cores. For high resolution grids (less than 500m), local convection is resolved using Large eddy simulation (LES) turbulent closure schemes. The LES technique provides a more detailed characterization of microscale turbulent flows using the complete Reynolds stress tensor for the sub filter scale parameterization.

  14. Release of potential instability by mesoscale triggering - An objective model simulation. [in precipitation numerical weather forecasting

    NASA Technical Reports Server (NTRS)

    Matthews, D. A.

    1978-01-01

    The effects of mesoscale triggering on organized nonsevere convective cloud systems in the High Plains are considered. Two experiments were conducted to determine if a one-dimensional quasi-time dependent model could (1) detect soundings which were sensitive to mesoscale triggering, and (2) discriminate between cases which had mesoscale organized convection and those with no organized convection. The MESOCU model was used to analyze the available potential instability and thermodynamic potential for cloud growth. It is noted that lifting is a key factor in the release of available potential instability on the High Plains.

  15. Probabilistic flood damage modelling at the meso-scale

    NASA Astrophysics Data System (ADS)

    Kreibich, Heidi; Botto, Anna; Schröter, Kai; Merz, Bruno

    2014-05-01

    Decisions on flood risk management and adaptation are usually based on risk analyses. Such analyses are associated with significant uncertainty, even more if changes in risk due to global change are expected. Although uncertainty analysis and probabilistic approaches have received increased attention during the last years, they are still not standard practice for flood risk assessments. Most damage models have in common that complex damaging processes are described by simple, deterministic approaches like stage-damage functions. Novel probabilistic, multi-variate flood damage models have been developed and validated on the micro-scale using a data-mining approach, namely bagging decision trees (Merz et al. 2013). In this presentation we show how the model BT-FLEMO (Bagging decision Tree based Flood Loss Estimation MOdel) can be applied on the meso-scale, namely on the basis of ATKIS land-use units. The model is applied in 19 municipalities which were affected during the 2002 flood by the River Mulde in Saxony, Germany. The application of BT-FLEMO provides a probability distribution of estimated damage to residential buildings per municipality. Validation is undertaken on the one hand via a comparison with eight other damage models including stage-damage functions as well as multi-variate models. On the other hand the results are compared with official damage data provided by the Saxon Relief Bank (SAB). The results show, that uncertainties of damage estimation remain high. Thus, the significant advantage of this probabilistic flood loss estimation model BT-FLEMO is that it inherently provides quantitative information about the uncertainty of the prediction. Reference: Merz, B.; Kreibich, H.; Lall, U. (2013): Multi-variate flood damage assessment: a tree-based data-mining approach. NHESS, 13(1), 53-64.

  16. Meso-scale modeling of irradiated concrete in test reactor

    DOE PAGESBeta

    Giorla, Alain B.; Vaitová, M.; Le Pape, Yann; Štemberk, P.

    2015-10-18

    In this paper, we detail a numerical model accounting for the effects of neutron irradiation on concrete at the mesoscale. Irradiation experiments in test reactor (Elleuch et al.,1972), i.e., in accelerated conditions, are simulated. Concrete is considered as a two-phase material made of elastic inclusions (aggregate) subjected to thermal and irradiation-induced swelling and embedded in a cementitious matrix subjected to shrinkage and thermal expansion. The role of the hardened cement paste in the post-peak regime (brittle-ductile transition with decreasing loading rate), and creep effects are investigated. Radiation-induced volumetric expansion (RIVE) of the aggregate cause the development and propagation of damagemore » around the aggregate which further develops in bridging cracks across the hardened cement paste between the individual aggregate particles. The development of damage is aggravated when shrinkage occurs simultaneously with RIVE during the irradiation experiment. The post-irradiation expansion derived from the simulation is well correlated with the experimental data and, the obtained damage levels are fully consistent with previous estimations based on a micromechanical interpretation of the experimental post-irradiation elastic properties (Le Pape et al.,2015). In conclusion, the proposed modeling opens new perspectives for the interpretation of test reactor experiments in regards to the actual operation of light water reactors.« less

  17. Meso-scale modeling of irradiated concrete in test reactor

    SciTech Connect

    Giorla, Alain B.; Vaitová, M.; Le Pape, Yann; Štemberk, P.

    2015-10-18

    In this paper, we detail a numerical model accounting for the effects of neutron irradiation on concrete at the mesoscale. Irradiation experiments in test reactor (Elleuch et al.,1972), i.e., in accelerated conditions, are simulated. Concrete is considered as a two-phase material made of elastic inclusions (aggregate) subjected to thermal and irradiation-induced swelling and embedded in a cementitious matrix subjected to shrinkage and thermal expansion. The role of the hardened cement paste in the post-peak regime (brittle-ductile transition with decreasing loading rate), and creep effects are investigated. Radiation-induced volumetric expansion (RIVE) of the aggregate cause the development and propagation of damage around the aggregate which further develops in bridging cracks across the hardened cement paste between the individual aggregate particles. The development of damage is aggravated when shrinkage occurs simultaneously with RIVE during the irradiation experiment. The post-irradiation expansion derived from the simulation is well correlated with the experimental data and, the obtained damage levels are fully consistent with previous estimations based on a micromechanical interpretation of the experimental post-irradiation elastic properties (Le Pape et al.,2015). In conclusion, the proposed modeling opens new perspectives for the interpretation of test reactor experiments in regards to the actual operation of light water reactors.

  18. URBAN MORPHOLOGICAL ANALYSIS FOR MESOSCALE METEOROLOGICAL AND DISPERSION MODELING APPLICATIONS: CURRENT ISSUES

    EPA Science Inventory

    Representing urban terrain characteristics in mesoscale meteorological and dispersion models is critical to produce accurate predictions of wind flow and temperature fields, air quality, and contaminant transport. A key component of the urban terrain representation is the charac...

  19. DEVELOPMENT OF MESOSCALE AIR QUALITY SIMULATION MODELS. VOLUME 5. USER'S GUIDE TO THE MESOFILE POSTPROCESSING PACKAGE

    EPA Science Inventory

    The MESOscale FILE management and analysis package (MESOFILE) is a highly flexible postprocessing system designed especially for interface with the MESOPLUME, MESOPUFF, and MESOGRID regional-scale air quality models, and the MESOPAC meteorology package. The MESOFILE package is co...

  20. STATISTICAL MECHANICS MODELING OF MESOSCALE DEFORMATION IN METALS

    SciTech Connect

    Anter El-Azab

    2013-04-08

    The research under this project focused on a theoretical and computational modeling of dislocation dynamics of mesoscale deformation of metal single crystals. Specifically, the work aimed to implement a continuum statistical theory of dislocations to understand strain hardening and cell structure formation under monotonic loading. These aspects of crystal deformation are manifestations of the evolution of the underlying dislocation system under mechanical loading. The project had three research tasks: 1) Investigating the statistical characteristics of dislocation systems in deformed crystals. 2) Formulating kinetic equations of dislocations and coupling these kinetics equations and crystal mechanics. 3) Computational solution of coupled crystal mechanics and dislocation kinetics. Comparison of dislocation dynamics predictions with experimental results in the area of statistical properties of dislocations and their field was also a part of the proposed effort. In the first research task, the dislocation dynamics simulation method was used to investigate the spatial, orientation, velocity, and temporal statistics of dynamical dislocation systems, and on the use of the results from this investigation to complete the kinetic description of dislocations. The second task focused on completing the formulation of a kinetic theory of dislocations that respects the discrete nature of crystallographic slip and the physics of dislocation motion and dislocation interaction in the crystal. Part of this effort also targeted the theoretical basis for establishing the connection between discrete and continuum representation of dislocations and the analysis of discrete dislocation simulation results within the continuum framework. This part of the research enables the enrichment of the kinetic description with information representing the discrete dislocation systems behavior. The third task focused on the development of physics-inspired numerical methods of solution of the coupled

  1. Mesoscale Model Validation using Stable Water Isotopes: The isoWATFLOOD Model

    NASA Astrophysics Data System (ADS)

    Stadnyk, T.; Kouwen, N.; Edwards, T.; Gibson, J.; Pietroniro, A.

    2009-05-01

    A methodology to improve mesoscale model validation is developed by calibrating simulations of both water and isotope mass simultaneously. The isoWATFLOOD model simulates changes in oxygen-18 of streamflow and hydrological processes contributing to streamflow. The added constraint of simulated to measured delta oxygen-18 in streamflow lowers the models degrees of freedom and generates more physically-based model parameterizations. Modelled results are shown to effectively reduce and constrain errors associated with equifinality in streamflow generation, providing a practical new approach for the assessment of mesoscale modelling. The WATFLOOD model is a conceptually-based distributed hydrological model used for simulating streamflow on mesoscale watersheds. Given the model's intended application to mesoscale hydrology, it remains crucial to ensure conceptualizations are physically representative of the hydrologic cycle and the natural environment. Building upon the existing flowpath-separation module within WATFLOOD, the capability to simulate changes in oxygen-18 through each component of the hydrological cycle is introduced. Masses of heavy-isotope are computed for compartmental storages; compartmental flows transfer flux-weighted portions of isotope mass between storages; and mass outflows from each compartment simultaneously combine to form the resultant channel flow composition. Heavy-isotope compositions are enriched when storages undergo evaporation resulting from the loss of isotopically-depleted vapour described by the well-known Craig & Gordon isotopic fractionation model. The isoWATFLOOD model is forced by oxygen-18 in rain, oxygen-18 in snow, and relative humidity; and requires no additional parameterizations of WATFLOOD. The first mesoscale, continuous simulations of changes in oxygen-18 in streamflow are presented for the remote Fort Simpson basin in Northwest Territories, Canada and for the largely populated Grand River Basin in south western Ontario

  2. Mesoscale numerical modeling of plastic bonded explosives under shock loading

    NASA Astrophysics Data System (ADS)

    Shang, Hailin; Zhao, Feng; Ji, Guangfu; Fu, Hua

    2015-09-01

    Mesoscale responses of plastic bonded explosives under shock loading are investigated using material point method as implemented in the Uintah Computational Framework. The two-dimensional geometrical model which can approximately reflect the mesoscopic structure of plastic bonded explosives was created based on the Voronoi tessellation. Shock loading for the explosive was performed by a piston moving at a constant velocity. For the purpose of investigating the influence of shock strength on the responses of explosives, two different velocities for the piston were used, 200 m/s and 400 m/s, respectively. The simulation results indicate that under shock loading there forms some stress localizations on the grain boundary of explosive. These stress localizations lead to large plastic deformations, and the plastic strain energy transforms to thermal energy immediately, causing temperature to rise rapidly and form some hot spots on grain boundary areas. The comparison between two different piston velocities shows that with increasing shock strength, the distribution of plastic strain and temperature does not have significant change, but their values increase obviously. Namely, the higher the shock strength is, the higher the hot spot temperature will be.

  3. Advances in CBL Budgetting and Inverse Modelling by Applying an Off-the-shelf Mesoscale Model

    NASA Astrophysics Data System (ADS)

    van der Molen, M. K.; Dolman, H.; Ronda, R. J.

    2005-12-01

    Eddy flux towers measure carbon sinks/sources at a local scale (~0.1 km), with the CBL budget method fluxes may be determined at a landscape scale (~1 km), and inverse models may determine the source/sink distribution at a global/continental scale (~1000-10000 km). Although currently efforts are made to increase the resolution of inverse models to the regional scale (~100 km), the meso-scale (100-1000 km) is rather badly represented in this spectrum of approaches. Boundary layer profiles contain signatures of mesoscale processes, such as the effect of wind divergence, topography and forest breezes on the boundary layer height and the subsidence velocity. 3-D advection of resulting concentration gradients is one of the main reasons of failure of the CBL budget approach and the representation error in inverse models and may be addressed in mesoscale atmospheric models. This study shows that considerable improvement may be obtained in the interpretation of boundary layer profiles by running an off-the-shelf mesoscale model without detailed prior knowlegde of the surface flux distribution. The simulations were carried out in the region around Zotino, Central Siberia to aid the interpretation of profile observations collected as part of TCOS-Siberia.

  4. A concurrent precursor inflow method for LES of atmospheric boundary layer flows with variable inflow direction for coupling with meso-scale models

    NASA Astrophysics Data System (ADS)

    Munters, Wim; Meneveau, Charles; Meyers, Johan

    2014-11-01

    In order to incorporate multiple scales of meteorological phenomena in atmospheric simulations, subsequent nesting of meso-scale models is often used. However, the spatial and temporal resolution in such models is too coarse to resolve the three-dimensional turbulent eddies that are characteristic for atmospheric boundary layer flows. This motivates the development of tools to couple meso-scale models to Large-Eddy Simulations (LES), in which turbulent fluctuations are explicitly resolved. A major challenge in this area is the spin-up region near the inlet of the LES in which the flow has to evolve from a RANS-like inflow, originating from the meso-scale model, to a fully turbulent velocity field. We propose a generalized concurrent precursor inflow method capable of imposing boundary conditions for time-varying inflow directions. The method is based on a periodic fully-developed precursor boundary-layer simulation that is dynamically rotated with the wind direction that drives the main LES. In this way realistic turbulent inflow conditions are applied while still retaining flexibility to dynamically adapt to meso-scale variations in wind directions. Applications to wind simulations with varying inflow directions, and comparisons to conventional coupling methods are shown. Work supported by ERC (ActiveWindFarms, Grant No: 306471). CM is supported by NSF (Grant No. 1243482).

  5. Nested Logit Models for Multiple-Choice Item Response Data

    ERIC Educational Resources Information Center

    Suh, Youngsuk; Bolt, Daniel M.

    2010-01-01

    Nested logit item response models for multiple-choice data are presented. Relative to previous models, the new models are suggested to provide a better approximation to multiple-choice items where the application of a solution strategy precedes consideration of response options. In practice, the models also accommodate collapsibility across all…

  6. Mesoscale thermal model for urban heat island mitigation

    NASA Astrophysics Data System (ADS)

    Silva, Humberto Ramon

    A simple energy balance model is created for use in developing mitigation strategies for the Urban Heat Island (UHI) effect. The model is applied to the city of Phoenix, Arizona, USA. There are six primary contributions to the overall energy balance: incident solar radiation, anthropogenic heat input, conduction heat loss, outgoing evapotranspiration, outgoing convection, and outgoing emitted radiation. The model temperature is shown to have the same periodic behavior as the experimentally measured air temperatures. The present model, while maintaining valid energy-balance physics, allows users to quickly and easily predict the relative effects of urban heat island mitigation measures. Accordingly, this model is applied here to show the relative effects of four common mitigation strategies: increasing the overall (1) emissivity, (2) percentage of vegetated area, (3) thermal conductivity, and (4) albedo of the urban environment in a series of percentage increases by 5, 10, 15, and 20 percent from baseline values. In addition to modeling mitigation strategies, the model is utilized to evaluate human health vulnerability from excessive heat-related events, based on heat-related emergency service data from 2002 to 2006. The four modeled UHI mitigation strategies, taken in combination, would lead to a 48 percent reduction in annual heat-related emergency service calls, where increasing the albedo is the single most effective UHI mitigation strategy. Finally, a spatial superposition design is presented that couples this model with the more robust fifth-generation Pennsylvania State University - National Center for Atmospheric Research Mesoscale Model (MM5). As a result, a new hypothesis is conceived which states that perturbation values from the norm temperature do not change when certain mitigation strategies are imposed. It is shown from demonstrative spatial mitigation schemes that having a fewer number of mitigated points (by almost half) on a square urban grid in

  7. Evaluating the extreme precipitation events using a mesoscale atmopshere model

    NASA Astrophysics Data System (ADS)

    Yucel, I.; Onen, A.

    2012-04-01

    Evidence is showing that global warming or climate change has a direct influence on changes in precipitation and the hydrological cycle. Extreme weather events such as heavy rainfall and flooding are projected to become much more frequent as climate warms. Mesoscale atmospheric models coupled with land surface models provide efficient forecasts for meteorological events in high lead time and therefore they should be used for flood forecasting and warning issues as they provide more continuous monitoring of precipitation over large areas. This study examines the performance of the Weather Research and Forecasting (WRF) model in producing the temporal and spatial characteristics of the number of extreme precipitation events observed in West Black Sea Region of Turkey. Extreme precipitation events usually resulted in flood conditions as an associated hydrologic response of the basin. The performance of the WRF system is further investigated by using the three dimensional variational (3D-VAR) data assimilation scheme within WRF. WRF performance with and without data assimilation at high spatial resolution (4 km) is evaluated by making comparison with gauge precipitation and satellite-estimated rainfall data from Multi Precipitation Estimates (MPE). WRF-derived precipitation showed capabilities in capturing the timing of the precipitation extremes and in some extent spatial distribution and magnitude of the heavy rainfall events. These precipitation characteristics are enhanced with the use of 3D-VAR scheme in WRF system. Data assimilation improved area-averaged precipitation forecasts by 9 percent and at some points there exists quantitative match in precipitation events, which are critical for hydrologic forecast application.

  8. An Overview of Mesoscale Material Modeling with Eulerian Hydrocodes

    NASA Astrophysics Data System (ADS)

    Benson, David

    2013-06-01

    Eulerian hydrocodes were originally developed for simulating strong shocks in solids and fluids, but their ability to handle arbitrarily large deformations and the formation of new free surfaces makes them attractive for simulating the deformation and failure of materials at the mesoscopic scale. A summary of some of the numerical techniques that have been developed to address common issues for this class of problems is presented with the shock compression of powders used as a model problem. Achieving the correct packing density with the correct statistical distribution of particle sizes and shapes is, in itself, a challenging problem. However, since Eulerian codes permit multiple materials within each element, or cell, the material interfaces do not have to follow the mesh lines. The use of digital image processing to map the pixels of micrographs to the Eulerian mesh has proven to be a popular and useful means of creating accurate models of complex microstructures. Micro CT scans have been used to extend this approach to three dimensions for several classes of materials. The interaction between the particles is of considerable interest. During shock compression, individual particles may melt and form jets, and the voids between them collapse. Dynamic interface ordering has become a necessity, and many codes now have a suite of options for handling multi-material mechanics. True contact algorithms are now replacing multi-material approximations in some cases. At the mesoscale, material properties often vary spatially due to sub-scale effects. Using a large number of material species to represent the variations is usually unattractive. Directly specifying the properties point-wise as history variables has not proven successful because the limiters in the transport algorithms quickly smooth out the variations. Circumventing the limiter problem is shown to be relatively simple with the use of a reference configuration and the transport of the initial coordinates

  9. Weather Research and Forecasting Model with Vertical Nesting Capability

    Energy Science and Technology Software Center (ESTSC)

    2014-08-01

    The Weather Research and Forecasting (WRF) model with vertical nesting capability is an extension of the WRF model, which is available in the public domain, from www.wrf-model.org. The new code modifies the nesting procedure, which passes lateral boundary conditions between computational domains in the WRF model. Previously, the same vertical grid was required on all domains, while the new code allows different vertical grids to be used on concurrently run domains. This new functionality improvesmore » WRF's ability to produce high-resolution simulations of the atmosphere by allowing a wider range of scales to be efficiently resolved and more accurate lateral boundary conditions to be provided through the nesting procedure.« less

  10. Weather Research and Forecasting Model with Vertical Nesting Capability

    SciTech Connect

    2014-08-01

    The Weather Research and Forecasting (WRF) model with vertical nesting capability is an extension of the WRF model, which is available in the public domain, from www.wrf-model.org. The new code modifies the nesting procedure, which passes lateral boundary conditions between computational domains in the WRF model. Previously, the same vertical grid was required on all domains, while the new code allows different vertical grids to be used on concurrently run domains. This new functionality improves WRF's ability to produce high-resolution simulations of the atmosphere by allowing a wider range of scales to be efficiently resolved and more accurate lateral boundary conditions to be provided through the nesting procedure.

  11. Observation Denial and Performance of a Local Mesoscale Model

    NASA Technical Reports Server (NTRS)

    Watson, Leela R.; Bauman, William H., III

    2009-01-01

    Forecasters at the 45th Weather Squadron (45 WS) use observations from the Kennedy Space Center (KSC) and Cape Canaveral Air Force Station (CCAFS) wind tower network and the CCAFS (XMR) daily rawinsonde observations (RAOB) to issue and verify wind advisories and warnings for operations. These observations are also used by the Spaceflight Meteorology Group (SMG) in Houston, Texas and the Melbourne, Florida National Weather Service office to initialize their locally run mesoscale models. SMG also uses the observations to support shuttle landings at the KSC Shuttie Landing Facility. Due to impending budget cuts, some or all of the KSC/CCAFS wind towers on the east-central Florida mainland and the XMR RAOBs may be eliminated. The loss of these data may impact the forecast capability of the 45 WS and SMG. The Applied Meteorology Unit (AMU) was tasked to conduct a modeling study to determine how important these observations are to the accuracy of the model output used by the forecasters as input to their forecasts. To accomplish this, the AMU performed a sensitivity study using the Weather Research and Forecasting (NRF) model initialized with and without KSC/CCAFS wind tower and XMR RAOB observations. The AMU assessed the accuracy of model output by comparing peak wind forecasts with operationally significant wind advisory and warning criteria forecast by the 45 WS. To assess model performance when initialized with and without some of the wind tower and XMR RAOB observations, the AMU conducted a subjective analysis by displaying model wind forecasts graphically with the observations overlaid for comparison and they conducted an objective analysis by comparing the maximum peak wind forecast to the maximum peak wind observed within the KSC/CCAFS wind tower network. Data were collected for twelve warm season cases and eight cool season cases from June - September 2007 and November - January 2008, respectively. For each case chosen, the 45 WS must have issued a wind advisory

  12. Mesoscale Modeling During Mixed-Phase Arctic Cloud Experiment

    SciTech Connect

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

    2005-03-18

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

  13. Mesoscale modelling of water vapour in the tropical UTLS: two case studies from the HIBISCUS campaign

    NASA Astrophysics Data System (ADS)

    Marécal, V.; Durry, G.; Longo, K.; Freitas, S.; Rivière, E. D.; Pirre, M.

    2006-08-01

    In this study, we evaluate the ability of the BRAMS mesoscale model compared to ECMWF global analysis to simulate the observed vertical variations of water vapour in the tropical upper troposphere and lower stratosphere (UTLS). The observations are balloon-borne measurements of water vapour mixing ratio and temperature from micro-SDLA (Tunable Diode Laser Spectrometer) instrument. Data from two balloon flights performed during the 2004 HIBISCUS field campaign are used to compare with the mesoscale simulations and to ECMWF analysis. The mesoscale model performs significantly better than ECMWF analysis for water vapour in the upper troposphere and similarly or slightly worse for temperature. The improvement provided by the mesoscale model for water vapour comes mainly from (i) the enhanced vertical resolution in the UTLS (250 m for BRAMS and ~1 km for ECMWF model) and (ii) the more detailed microphysical parameterization providing ice supersaturations as in the observations. The ECMWF vertical resolution (~1 km) is too coarse to capture the observed fine scale vertical variations of water vapour in the UTLS. In near saturated or supersaturated layers, the mesoscale model relative humidity with respect to ice saturation is close to observations provided that the temperature profile is realistic. For temperature, ECMWF analysis gives good results partly thanks to data assimilation. The analysis of the mesoscale model results showed that in undersaturated layers, the water vapour profile depends mainly on the dynamics. In saturated/supersaturated layers, microphysical processes play an important role and have to be taken into account on top of the dynamical processes to understand the water vapour profiles. In the lower stratosphere, the ECMWF model and the BRAMS model give very similar water vapour profiles that are significantly dryer than micro-SDLA measurements. This similarity comes from the fact that BRAMS is initialised using ECMWF analysis and that no mesoscale

  14. Evaluation of a Mesoscale Atmospheric Dispersion Modeling System with Observations from the 1980 Great Plains Mesoscale Tracer Field Experiment. Part I: Datasets and Meteorological Simulations.

    NASA Astrophysics Data System (ADS)

    Moran, Michael D.; Pielke, Roger A.

    1996-03-01

    The Colorado State University mesoscale atmospheric dispersion (MAD) numerical modeling system, which consists of a prognostic mesoscale meteorological model coupled to a mesoscale Lagrangian particle dispersion model, has been used to simulate the transport and diffusion of a perfluorocarbon tracer-gas cloud for one afternoon surface release during the July 1980 Great Plains mesoscale tracer field experiment. Ground-level concentration (GLC) measurements taken along arcs of samplers 100 and 600 km downwind of the release site at Norman, Oklahoma, up to three days after the tracer release were available for comparison. Quantitative measures of a number of significant dispersion characteristics obtained from analysis of the observed tracer cloud's moving GLC `footprint' have been used to evaluate the modeling system's skill in simulating this MAD case.MAD is more dependent upon the spatial and temporal structure of the transport wind field than is short-range atmospheric dispersion. For the Great Plains mesoscale tracer experiment, the observations suggest that the Great Plains nocturnal low-level jet played an important role in transporting and deforming the tracer cloud. A suite of ten two- and three-dimensional numerical meteorological experiments was devised to investigate the relative contributions of topography, other surface inhomogeneities, atmospheric baroclinicity, synoptic-scale flow evolution, and meteorological model initialization time to the structure and evolution of the low-level mesoscale flow field and thus to MAD. Results from the ten mesoscale meteorological simulations are compared in this part of the paper. The predicted wind fields display significant differences, which give rise in turn to significant differences in predicted low-level transport. The presence of an oscillatory ageostrophic component in the observed synoptic low-level winds for this case is shown to complicate initialization of the meteorological model considerably and is the

  15. A nested grid, nonhydrostatic, elastic model using a terrain-following coordinate transformation - The radiative-nesting boundary conditions

    NASA Technical Reports Server (NTRS)

    Chen, Chaing

    1991-01-01

    This study presents a nested-grid nonhydrostatic and elastic model using a terrain-following coordinate transformation as well as a unique application of grid-nesting techniques to the time-splitting elastic model. A simulation of the 10-m-high Witch of Agnesi Mountain provides the control to test this new model. The results show that the model produces the same solution as that derived from a simple linear analytic model. It is demonstrated that the new nested-grid model improves model resolution without resorting to the costly method of placing a fine-resolution grid over the entire domain. Since the wave reflection from the boundaries of the fine-grid model is well controlled, the boundary of the nested fine-grid model can be located even at the wave-active region. The model can be used to simulate various weather systems in which scale interactions are important.

  16. Two-dimensional simulations of possible mesoscale effects of nuclear war fires: 1. Model description

    NASA Astrophysics Data System (ADS)

    Giorgi, Filippo

    1989-01-01

    In this paper and the companion paper by Giorgi and Visconti [this issue] a two-dimensional mesoscale meteorological model is coupled to an aerosol model to investigate possible mesoscale effects of nuclear war fires. The meteorological model used in this study is a two-dimensional analog of the Penn State/NCAR mesoscale model with enhancements in the areas of radiative transfer, surface physics, and moisture physics. The aerosol model solves equations for the hygroscopic and hydrophobic fractions of particulate material and includes particle transport, sedimentation, dry-deposition, in-cloud and below-cloud scavenging, and a first order term accounting for aerosol aging. In this paper the meteorological model and the aerosol model are first described and then applied, as an illustrative example, to a simulation of the development of sea-breezelike circulations induced by contrasts in soil moisture available for evaporation.

  17. Two-dimensional simulations of possible mesoscale effects of nuclear war fires 1. Model description

    SciTech Connect

    Giorgi, F.

    1989-01-20

    In this paper and the companion paper by Giorgi and Visconti (this issue) a two-dimensional mesoscale meteorological model is coupled to an aerosol model to investigate possible mesoscale effects of nuclear war fires. The meteorological model used in this study is a two-dimensional analog of the Penn State/NCAR mesoscale model with enhancements in the areas of radiative transfer, surface physics, and moisture physics. The aerosol model solves equations for the hygroscopic and hydrophobic fractions of particulate material and includes particle transport, sedimentation, dry-deposition, in-cloud and below-cloud scavenging, and a first order term accounting for aerosol aging. In this paper the meteorological model and the aerosol model are first described and then applied, as an illustrative example, to a simulation of the development of sea-breezelike circulations induced by contrasts in soil moisture available for evaporation. copyright American Geophysical Union 1989

  18. Interpreting the suspended sediment dynamics in a mesoscale river basin of Central Mexico using a nested watershed approach

    NASA Astrophysics Data System (ADS)

    Duvert, C.; Némery, J.; Gratiot, N.; Prat, C.; Collet, L.; Esteves, M.

    2009-12-01

    at the outlet, with a dominance of cohesive sediments (mainly silt and clay). Sediment delivery dynamics was found to be seasonally dependent and principally driven by the river network transport capacity. With the exception of events associated with a very high discharge peak, sub-catchments delivered very little sediment to the basin’s outlet during first events of the rainy season (corresponding to May-June period). Later on (from July until the end of the season), even low headwater sediment peaks were coupled with significant sediment fluxes at the outlet. An analysis of SSC-Q hysteresis patterns was also conducted for major flood events at each site. Anti-clockwise SSC-Q hysteresis loops were recorded most frequently at the three upland sub-catchments, while at the outlet a double-peaked SSC signal was repeatedly detected, outlining the variety in sediment contributions. The findings of this nested watershed approach suggest that during the first part of the rainy season, fine sediment loads exported from active hillslopes deposit as fluid mud layers in the lowland river channels. Once the in-channel storage capacity is loaded, the river transport potential guarantees a direct transit between headwater areas and delivery zones.

  19. Large-eddy simulation coupled to mesoscale meteorological model for gas dispersion in an urban district

    NASA Astrophysics Data System (ADS)

    Michioka, T.; Sato, A.; Sada, K.

    2013-08-01

    A microscale large-eddy simulation (LES) model coupled to a mesoscale LES model is implemented to estimate a ground concentration considering the meteorological influence in an actual urban district. The microscale LES model is based on a finite volume method with an unstructured grid system to resolve the flow structure in a complex geometry. The Advanced Regional Prediction System (ARPS) is used for mesoscale meteorological simulation. To evaluate the performance of the LES model, 1-h averaged concentrations are compared with those obtained by field measurements, which were conducted for tracer gas dispersion from a point source on the roof of a tall building in Tokyo. The concentrations obtained by the LES model without combing the mesoscale LES model are in quite good agreement with the wind-tunnel experimental data, but overestimates the 1 h averaged ground concentration in the field measurements. On the other hand, the ground concentrations using the microscale LES model coupled to the mesoscale LES are widely distributed owing to large-scale turbulent motions generated by the mesoscale LES, and the concentrations are nearly equal to the concentrations from the field measurements.

  20. Assessing the interaction of mountain waves and katabatic flows using a mesoscale model

    SciTech Connect

    Poulos, G.S.; Bossert, J.E.; McKee, T.B.; Pielke, A.

    1996-07-01

    This paper has two main purposes. The first is to evaluate the interaction of two common complex terrain meteorological phenomena, katabatic flow and mountain waves. Although occasionally investigated together, generally, the large body of literature regarding them has treated each individually. The second purpose is to show the reader the utility of extracting high time resolution data sets of (1) standard meteorological variables, and (2) seldom used, components of the model equations. Using such time series, significant variability is found in the evolving, clear sky, nocturnal boundary layer, when meteorological variability is generally considered to be at its lowest point diurnally. The approach is to use results from three, 3-d, realistic topography simulations produced by the Regional Atmospheric Modeling System (RAMS). RAMS is a primitive equation mesoscale model formulated in {sigma} coordinates. The model is set up with five nested grids that focus on Eldorado Canyon, which is embedded in the Front Range slope of Colorado. On the finest grid {Delta}x = {Delta}y = 400 m and {Delta}z = 20 m for the lowest 400 m above ground level (AGL). The three simulations were: (1) a realistic simulation; (2) the same as (1) but without radiative forcing (referred to as mountain wave only or MWO) and (3) the same as (1) but without boundary nudging and no initial winds (referred to as katabatic flow only or KFO). The case night is 3--4 Sep 1993 from the Atmospheric Studies in Complex Terrain (ASCOT) 1993 field program near Rocky Flats, Colorado. Both mountain waves and katabatic flows were occurring on this night.

  1. A Study of Mesoscale Gravity Waves over the North Atlantic with Satellite Observations and a Mesoscale Model

    NASA Technical Reports Server (NTRS)

    Wu, Dong L.; Zhang, Fuqing

    2004-01-01

    Satellite microwave data are used to study gravity wave properties and variabilities over the northeastern United States and the North Atlantic in the December-January periods. The gravity waves in this region, found in many winters, can reach the stratopause with growing amplitude. The Advanced Microwave Sounding Unit-A (AMSU-A) observations show that the wave occurrences are correlated well with the intensity and location of the tropospheric baroclinic jet front systems. To further investigate the cause(s) and properties of the North Atlantic gravity waves, we focus on a series of wave events during 19-21 January 2003 and compare AMSU-A observations to simulations from a mesoscale model (MM5). The simulated gravity waves compare qualitatively well with the satellite observations in terms of wave structures, timing, and overall morphology. Excitation mechanisms of these large-amplitude waves in the troposphere are complex and subject to further investigations.

  2. A Nonparametric Bayesian Model for Nested Clustering.

    PubMed

    Lee, Juhee; Müller, Peter; Zhu, Yitan; Ji, Yuan

    2016-01-01

    We propose a nonparametric Bayesian model for clustering where clusters of experimental units are determined by a shared pattern of clustering another set of experimental units. The proposed model is motivated by the analysis of protein activation data, where we cluster proteins such that all proteins in one cluster give rise to the same clustering of patients. That is, we define clusters of proteins by the way that patients group with respect to the corresponding protein activations. This is in contrast to (almost) all currently available models that use shared parameters in the sampling model to define clusters. This includes in particular model based clustering, Dirichlet process mixtures, product partition models, and more. We show results for two typical biostatistical inference problems that give rise to clustering. PMID:26519174

  3. Numerical Model Studies of the Martian Mesoscale Circulations

    NASA Technical Reports Server (NTRS)

    Segal, M.; Arritt, R. W.

    1996-01-01

    Studies concerning mesoscale topographical effects on Martian flows examined low-level jets in the near equatorial latitudes and the dynamical intensification of flow by steep terrain. Continuation of work from previous years included evaluating the dissipation of cold air mass outbreaks due to enhanced sensible heat flux, further sensitivity and scaling evaluations for generalization of the characteristics of Martian mesoscale circulation caused by horizontal sensible heat-flux gradients, and evaluations of the significance that non-uniform surface would have on enhancing the polar CO2 ice sublimation during the spring. The sensitivity of maximum and minimum atmospheric temperatures to changes in wind speed, surface albedo, and deep soil temperature was investigated.

  4. A two-moment bulk microphysics coupled with a mesoscale model WRF: Model description and first results

    NASA Astrophysics Data System (ADS)

    Gao, Wenhua; Zhao, Fengsheng; Hu, Zhijin; Feng, Xuan

    2011-09-01

    The Chinese Academy of Meteorological Sciences (CAMS) two-moment bulk microphysics scheme was adopted in this study to investigate the representation of cloud and precipitation processes under different environmental conditions. The scheme predicts the mixing ratio of water vapor as well as the mixing ratios and number concentrations of cloud droplets, rain, ice, snow, and graupel. A new parameterization approach to simulate heterogeneous droplet activation was developed in this scheme. Furthermore, the improved CAMS scheme was coupled with the Weather Research and Forecasting model (WRF v3.1), which made it possible to simulate the microphysics of clouds and precipitation as well as the cloud-aerosol interactions in selected atmospheric condition. The rain event occurring on 27-28 December 2008 in eastern China was simulated using the CAMS scheme and three sophisticated microphysics schemes in the WRF model. Results showed that the simulated 36-h accumulated precipitations were generally agreed with observation data, and the CAMS scheme performed well in the southern area of the nested domain. The radar reflectivity, the averaged precipitation intensity, and the hydrometeor mixing ratios simulated by the CAMS scheme were generally consistent with those from other microphysics schemes. The hydrometeor number concentrations simulated by the CAMS scheme were also close to the experiential values in stratus clouds. The model results suggest that the CAMS scheme performs reasonably well in describing the microphysics of clouds and precipitation in the mesoscale WRF model.

  5. Intercomparison of state-of-the-art models for wind energy resources with mesoscale models:

    NASA Astrophysics Data System (ADS)

    Olsen, Bjarke Tobias; Hahmann, Andrea N.; Sempreviva, Anna Maria; Badger, Jake; Joergensen, Hans E.

    2016-04-01

    1. Introduction Mesoscale models are increasingly being used to estimate wind conditions to identify perspective areas and sites where to develop wind farm projects. Mesoscale models are functional for giving information over extensive areas with various terrain complexities where measurements are scarce and measurement campaigns costly. Several mesoscale models and families of models are being used, and each often contains thousands of setup options. Since long-term integrations are expensive and tedious to carry out, only limited comparisons exist. To remedy this problem and for evaluating the capabilities of mesoscale models to estimate site wind conditions, a tailored benchmarking study has been co-organized by the European Wind Energy Association (EWEA) and the European Energy Research Alliance Joint Programme Wind Energy (EERA JP WIND). EWEA hosted results and ensured that participants were anonymous. The blind evaluation was performed at the Wind Energy Department of the Technical University of Denmark (DTU) with the following objectives: (1) To highlight common issues on mesoscale modelling of wind conditions on sites with different characteristics, and (2) To identify gaps and strengths of models and understand the root conditions for further evaluating uncertainties. 2. Approach Three experimental sites were selected: FINO 3 (offshore, GE), Høvsore (coastal, DK), and Cabauw (land-based, NL), and three other sites without observations based on . The three mast sites were chosen because the availability of concurrent suitable time series of vertical profiles of winds speed and other surface parameters. The participants were asked to provide hourly time series of wind speed, wind direction, temperature, etc., at various vertical heights for a complete year. The methodology used to derive the time series was left to the choice of the participants, but they were asked for a brief description of their model and many other parameters (e.g., horizontal and

  6. Modeling pulse characteristics in Xenon with NEST

    NASA Astrophysics Data System (ADS)

    Mock, J.; Barry, N.; Kazkaz, K.; Stolp, D.; Szydagis, M.; Tripathi, M.; Uvarov, S.; Woods, M.; Walsh, N.

    2014-04-01

    A comprehensive model for describing the characteristics of pulsed signals, generated by particle interactions in xenon detectors, is presented. An emphasis is laid on two-phase time projection chambers, but the models presented are also applicable to single phase detectors. In order to simulate the pulse shape due to primary scintillation light, the effects of the ratio of singlet and triplet dimer state populations, as well as their corresponding decay times, and the recombination time are incorporated into the model. In a two phase time projection chamber, when simulating the pulse caused by electroluminescence light, the ionization electron mean free path in gas, the drift velocity, singlet and triplet decay times, diffusion constants, and the electron trapping time, have been implemented. This modeling has been incorporated into a complete software package, which realistically simulates the expected pulse shapes for these types of detectors.

  7. Overshooting convection during TRO-pico: mesoscale modelling of two cases hydrating the lower stratosphere

    NASA Astrophysics Data System (ADS)

    Rivière, Emmanuel; Marécal, Virginie; Khaykin, Sergey; Amarouche, Nadir; Ghysels, Mélanie; Mappe-Fogaing, Irène; Behera, Abhinna; Held, Gerhard; França, Hermes

    2016-04-01

    One of the main aims of the TRO-pico project (2010-2015) was to study the variability of overshooting convection at the local scale to try to deduce a typical impact on the TTL water at the global scale. In this study, we've identified local maximum in the water vapour profiles gathered by the balloon-borne hygrometers Pico-SDLA and Flash above Bauru, Brazil (22.3 S) during the TRO-pico campaign. We tried to link them to overshooting cells in the surrounding of Bauru with a trajectory analysis. In this study we select a couple of cases of overshooting convection both sampled by the Bauru S-Band radar and by one of the balloon-borne instruments of the TRO-pico campaign in 2012 and 2013. The selected cases are the case of March 13, 2012 (hereafter M12), sounded by both hygrometers Pico-SDLA and FLASH, and the case of January 26, 2013 (hereafter J13), sounded by Pico-SDLA. For the M12 case, local water vapour enhancements at two different altitudes due to two different cells were reported, with local enhancement of about 0.65 ppmv. For the J26 case, the water enhancement was about 1 ppmv. The corresponding mesoscale simulations with the Brazilian Regional Atmospheric Modelling System (BRAMS) using 3 nested grids with horizontal resolution down to 800 m were carried out. Simulation results are compared to Bauru's radar echo tops and and water vapour in situ measurements. As for the M12 simulation, the model is doing a rather good job in reproducing several overshooting cells, both in severity and timing. Associated stratospheric water budget are computed for each cases.

  8. Case study modeling of turbulent and mesoscale fluxes over the BOREAS region

    USGS Publications Warehouse

    Vidale, P.L.; Pielke, R.A., Sr.; Steyaert, L.T.; Barr, A.

    1997-01-01

    Results from aircraft and surface observations provided evidence for the existence of mesoscale circulations over the Boreal Ecosystem-Atmosphere Study (BOREAS) domain. Using an integrated approach that included the use of analytical modeling, numerical modeling, and data analysis, we have found that there are substantial contributions to the total budgets of heat over the BOREAS domain generated by mesoscale circulations. This effect is largest when the synoptic flow is relatively weak, yet it is present under less favorable conditions, as shown by the case study presented here. While further analysis is warranted to document this effect, the existence of mesoscale flow is not surprising, since it is related to the presence of landscape patches, including lakes, which are of a size on the order of the local Rossby radius and which have spatial differences in maximum sensible heat flux of about 300 W m-2. We have also analyzed the vertical temperature profile simulated in our case study as well as high-resolution soundings and we have found vertical profiles of temperature change above the boundary layer height, which we attribute in part to mesoscale contributions. Our conclusion is that in regions with organized landscapes, such as BOREAS, even with relatively strong synoptic winds, dynamical scaling criteria should be used to assess whether mesoscale effects should be parameterized or explicitly resolved in numerical models of the atmosphere.

  9. Sensitivity of a mesoscale model to initial specification of relative humidity, liquid water and vertical motion

    NASA Technical Reports Server (NTRS)

    Kalb, M. W.; Perkey, D. J.

    1985-01-01

    The influence of synoptic scale initial conditions on the accuracy of mesoscale precipitation modeling is investigated. Attention is focused on the relative importance of the water vapor, cloud water, rain water, and vertical motion, with the analysis carried out using the Limited Area Mesoscale Prediction System (LAMPS). The fully moist primitive equation model has 15 levels and a terrain-following sigma coordinate system. A K-theory approach was implemented to model the planetary boundary layer. A total of 15 sensitivity simulations were run to investigate the effects of the synoptic initial conditions of the four atmospheric variables. The absence of synoptic cloud and rain water amounts in the initialization caused a 2 hr delay in the onset of precipitation. The delay was increased if synoptic-scale vertical motion was used instead of mesoscale values. Both the delays and a choice of a smoothed moisture field resulted in underestimations of the total rainfall.

  10. Integrating Visualizations into Modeling NEST Simulations

    PubMed Central

    Nowke, Christian; Zielasko, Daniel; Weyers, Benjamin; Peyser, Alexander; Hentschel, Bernd; Kuhlen, Torsten W.

    2015-01-01

    Modeling large-scale spiking neural networks showing realistic biological behavior in their dynamics is a complex and tedious task. Since these networks consist of millions of interconnected neurons, their simulation produces an immense amount of data. In recent years it has become possible to simulate even larger networks. However, solutions to assist researchers in understanding the simulation's complex emergent behavior by means of visualization are still lacking. While developing tools to partially fill this gap, we encountered the challenge to integrate these tools easily into the neuroscientists' daily workflow. To understand what makes this so challenging, we looked into the workflows of our collaborators and analyzed how they use the visualizations to solve their daily problems. We identified two major issues: first, the analysis process can rapidly change focus which requires to switch the visualization tool that assists in the current problem domain. Second, because of the heterogeneous data that results from simulations, researchers want to relate data to investigate these effectively. Since a monolithic application model, processing and visualizing all data modalities and reflecting all combinations of possible workflows in a holistic way, is most likely impossible to develop and to maintain, a software architecture that offers specialized visualization tools that run simultaneously and can be linked together to reflect the current workflow, is a more feasible approach. To this end, we have developed a software architecture that allows neuroscientists to integrate visualization tools more closely into the modeling tasks. In addition, it forms the basis for semantic linking of different visualizations to reflect the current workflow. In this paper, we present this architecture and substantiate the usefulness of our approach by common use cases we encountered in our collaborative work. PMID:26733860

  11. Network-based model of the growth of termite nests

    NASA Astrophysics Data System (ADS)

    Eom, Young-Ho; Perna, Andrea; Fortunato, Santo; Darrouzet, Eric; Theraulaz, Guy; Jost, Christian

    2015-12-01

    We present a model for the growth of the transportation network inside nests of the social insect subfamily Termitinae (Isoptera, termitidae). These nests consist of large chambers (nodes) connected by tunnels (edges). The model based on the empirical analysis of the real nest networks combined with pruning (edge removal, either random or weighted by betweenness centrality) and a memory effect (preferential growth from the latest added chambers) successfully predicts emergent nest properties (degree distribution, size of the largest connected component, average path lengths, backbone link ratios, and local graph redundancy). The two pruning alternatives can be associated with different genuses in the subfamily. A sensitivity analysis on the pruning and memory parameters indicates that Termitinae networks favor fast internal transportation over efficient defense strategies against ant predators. Our results provide an example of how complex network organization and efficient network properties can be generated from simple building rules based on local interactions and contribute to our understanding of the mechanisms that come into play for the formation of termite networks and of biological transportation networks in general.

  12. Network-based model of the growth of termite nests.

    PubMed

    Eom, Young-Ho; Perna, Andrea; Fortunato, Santo; Darrouzet, Eric; Theraulaz, Guy; Jost, Christian

    2015-12-01

    We present a model for the growth of the transportation network inside nests of the social insect subfamily Termitinae (Isoptera, termitidae). These nests consist of large chambers (nodes) connected by tunnels (edges). The model based on the empirical analysis of the real nest networks combined with pruning (edge removal, either random or weighted by betweenness centrality) and a memory effect (preferential growth from the latest added chambers) successfully predicts emergent nest properties (degree distribution, size of the largest connected component, average path lengths, backbone link ratios, and local graph redundancy). The two pruning alternatives can be associated with different genuses in the subfamily. A sensitivity analysis on the pruning and memory parameters indicates that Termitinae networks favor fast internal transportation over efficient defense strategies against ant predators. Our results provide an example of how complex network organization and efficient network properties can be generated from simple building rules based on local interactions and contribute to our understanding of the mechanisms that come into play for the formation of termite networks and of biological transportation networks in general. PMID:26764747

  13. a Mesoscale Atmospheric Dispersion Modeling System for Simulations of Topographically Induced Atmospheric Flow and Air Pollution Dispersion.

    NASA Astrophysics Data System (ADS)

    Boybeyi, Zafer

    A mesoscale atmospheric dispersion modeling system has been developed to investigate mesoscale circulations and associated air pollution dispersion, including effects of terrain topography, large water bodies and urban areas. The system is based on a three-dimensional mesoscale meteorological model coupled with two dispersion models (an Eulerian dispersion model and a Lagrangian particle dispersion model). The mesoscale model is hydrostatic and based on primitive equations formulated in a terrain-following coordinate system with a E-varepsilon turbulence closure scheme. The Eulerian dispersion model is based on numerical solution of the advection-diffusion equation to allow one to simulate releases of non-buoyant pollutants (especially from area and volume sources). The Lagrangian particle dispersion model allows one to simulate releases of buoyant pollutants from arbitrary sources (particularly from point and line sources). The air pollution dispersion models included in the system are driven by the meteorological information provided by the mesoscale model. Mesoscale atmospheric circulations associated with sea and lake breezes have been examined using the mesoscale model. A series of model sensitivity studies were performed to investigate the effects of different environmental parameters on these circulations. It was found that the spatial and temporal variation of the sea and lake breeze convergence zones and the associated convective activities depend to a large extent on the direction and the magnitude of the ambient wind. Dispersion of methyl isocyanate gas from the Bhopal accident was investigated using the mesoscale atmospheric dispersion modeling system. A series of numerical experiments were performed to investigate the possible role of the mesoscale circulations on this industrial gas episode. The temporal and spatial variations of the wind and turbulence fields were simulated with the mesoscale model. The dispersion characteristics of the accidental

  14. Mesoscale Backtracking by Means of Atmospheric Transport Modeling of Xenon Plumes Measured by Radionuclide Gas Stations

    NASA Astrophysics Data System (ADS)

    Armand, P. P.; Achim, P.; Taffary, T.

    2006-12-01

    The monitoring of atmospheric radioactive xenon concentration is performed for nuclear safety regulatory requirements. It is also planned to be used for the detection of hypothetical nuclear tests in the framework of the Comprehensive nuclear-Test-Ban Treaty (CTBT). In this context, the French Atomic Energy Commission designed a high sensitive and automated fieldable station, named SPALAX, to measure the activity concentrations of xenon isotopes in the atmosphere. SPALAX stations were set up in Western Europe and have been operated quite continuously for three years or more, detecting principally xenon-133 and more scarcely xenon-135, xenon-133m and xenon-131m. There are around 150 nuclear power plants in the European Union, research reactors, reprocessing plants, medical production and application facilities releasing radioactive xenon in normal or incidental operations. A numerical study was carried out aiming to explain the SPALAX measurements. The mesoscale Atmospheric Transport Modelling involves the MM5 suite (PSU- NCAR) to predict the wind fields on nested domains, and FLEXPART, a 3D Lagrangian particle dispersion code, used to simulate the backward transport of xenon plumes detected by the SPALAX. For every event of detection, at least one potential xenon source has a significant efficiency of emission. The identified likely sources are located quite close to the SPALAX stations (some tens of kilometres), or situated farther (a few hundreds of kilometres). A base line of some mBq per cubic meter in xenon-133 is generated by the nuclear power plants. Peaks of xenon-133 ranging from tens to hundreds of mBq per cubic meter originate from a radioisotope production facility. The calculated xenon source terms required to obtain the SPALAX measurements are discussed and seem consistent with realistic emissions from the xenon sources in Western Europe.

  15. The Impact of TRMM on Mesoscale Model Simulation of Super Typhoon Paka

    NASA Technical Reports Server (NTRS)

    Tao, W.-K.; Jia, Y.; Halverson, J.; Hou, A.; Olson, W.; Rodgers, E.; Simpson, J.

    1999-01-01

    Tropical cyclone Paka formed during the first week of December 1997 and underwent three periods of rapid intensification over the following two weeks. During one of these periods, which initiated early on December 10, Paka's Dvorak-measured windspeed increased from 23 to 60 m/s over a 48-hr period. On December 18, during the last rapid deepening episode, Paka became a supertyphoon with a maximum wind speed of about 80 m/s. In this study, the Penn State/NCAR Mesoscale Model (MM5) with improved physics (i.e., cloud microphysics, radiation, land-soil-vegetation-surface processes, and TOGA COARE flux scheme) and a multiple level nesting technique (135, 45 and 15 km horizontal resolution) will be used to simulate supertyphoon Paka. We performed two runs initialized with Goddard Earth Observing System (GEOS) data sets. The first GEOS data set does not incorporate either TRMM (tropical rainfall measuring mission satellite) or SSM/I (sensor microwave imager) observed rainfall fields into the GEOS's assimilation system while the second one does. Preliminary results show that the MM5 simulated surface pressure deepened by more than 25 mb (45 km resolution domain) in the run initialized with the GEOS data set incorporating TRMM and SSM/I derived rainfall, compared to the one initialized without. However, the track and precipitation patterns are quite similar between the runs. In our presentation, we will show the impact of TRMM rainfall upon the MM5 simulation of Paka at various horizontal resolutions. We will also examine the physical processes associated with initial explosive development by comparing MM5 simulated rainfall and latent heat release. In addition, budget (vorticity, PV, momentum and heat) calculations and sensitivity tests will be performed to examine the upper-tropospheric and SST mechanisms responsible for the explosive development of Paka.

  16. Macroscale modeling and mesoscale observations of plasma density structures in the polar cap

    SciTech Connect

    Basu, S.; Basu, S.; Sojka, J.J.

    1995-04-15

    The seasonal and UT variation of mesoscale structures (10 km - 100 m) in the central polar cap has been obtained from an analysis of 250-MHz intensity scintillation observations made at Thule, Greenland. It has been established earlier that mesoscale structures causing scintillations of satellite signals may develop at the edges of macroscale structures (several hundred km) such as discrete polar cap plasma density enhancements or patches through the gradient drift instability process. As such, the authors examined the seasonal and UT variation of polar cap patches simulated by using the USU Time Dependent Ionospheric Model (TDIM) under conditions of southward B{sub z}. A fairly remarkable similarity is found between the scintillation observations and the model predictions of patch occurrence. For instance, both the patch and scintillation occurrences are minimized during the winter solstice (northern hemisphere) between 0800-1200 UT while also having their largest seasonal intensity between 2000-2400 UT. Little UT dependence of patches and scintillations is seen at equinox with high intensity being observed throughout the day, while during local summer the intensity of macroscale patches and mesoscale irregularities are found to be a minimum at all UT. These results indicate that macroscale features in the polar cap are routinely associated with plasma instabilities giving rise to smaller scale structures and that the specific patch formation mechanism assumed in the simulation is consistent with the observations. This ability to bridge between macroscale modeling and mesoscale observations provides a natural framework for the modeling of mesoscale structures themselves. This mesoscale modeling, in turn, can be utilized in a variety of radar and communication systems applications in the polar region. 25 refs., 3 figs.

  17. A shallow convection parameterization for the non-hydrostatic MM5 mesoscale model

    SciTech Connect

    Seaman, N.L.; Kain, J.S.; Deng, A.

    1996-04-01

    A shallow convection parameterization suitable for the Pennsylvannia State University (PSU)/National Center for Atmospheric Research nonhydrostatic mesoscale model (MM5) is being developed at PSU. The parameterization is based on parcel perturbation theory developed in conjunction with a 1-D Mellor Yamada 1.5-order planetary boundary layer scheme and the Kain-Fritsch deep convection model.

  18. Assimilation of MGS Data Into a Coupled GCM-Mesoscale Model of the Martian Atmosphere

    NASA Technical Reports Server (NTRS)

    Rafkin, Scot C. R.; Haberle, Robert (Technical Monitor)

    2001-01-01

    The project sought to develop a coupled GCM-mesoscale model and to assimilate Mars Global Surveyor (MGS) data into the coupled model. To achieve the project goals, four specific research activities were proposed. These activities are reiterated for completeness and the progress in each of the activities is noted in future sections of this report.

  19. Nested-hierarchical scene models and image segmentation

    NASA Technical Reports Server (NTRS)

    Woodcock, C.; Harward, V. J.

    1992-01-01

    An improved model of scenes for image analysis purposes, a nested-hierarchical approach which explicitly acknowledges multiple scales of objects or categories of objects, is presented. A multiple-pass, region-based segmentation algorithm improves the segmentation of images from scenes better modeled as a nested hierarchy. A multiple-pass approach allows slow and careful growth of regions while interregion distances are below a global threshold. Past the global threshold, a minimum region size parameter forces development of regions in areas of high local variance. Maximum and viable region size parameters limit the development of undesirably large regions. Application of the segmentation algorithm for forest stand delineation in TM imagery yields regions corresponding to identifiable features in the landscape. The use of a local variance, adaptive-window texture channel in conjunction with spectral bands improves the ability to define regions corresponding to sparsely stocked forest stands which have high internal variance.

  20. The CAOS model: a physically based, flexible hydrological model for the mesoscale

    NASA Astrophysics Data System (ADS)

    Westhoff, Martijn; Zehe, Erwin

    2014-05-01

    Hydrological models are not only tools to predict discharge, but they are also hypotheses of how a catchment functions with respect to rainfall-runoff behaviour. In this work in progress, we present a new (physically based) model concept that should ultimately be suitable to run at the mesoscale. To be able to run it efficiently on the mesoscale, the model cannot be too complex. Yet, we wanted it physically based, with explicit incorporation of dissipative structures, such as macropores and lateral preferential flow paths. Besides water fluxes it should also be able to simulate solute concentrations and energy fluxes. This helps to parameterize the model while the model is also thermodynamically consistent, meaning that it is suitable to test thermodynamic optimality principles (such as maximum entropy production principle). With these constraints in mind, we developed a model where, in each subroutine, flow is modelled in only one dimension (vertical for the unsaturated zone and lateral for subsurface storm flow, groundwater flow and stream flow routines, making the model multiple 1-D), decreasing computation time significantly. The code is developed in an object oriented way, leading to more flexibility to test different model structures. For example, we will demonstrate the effect on simulated rapid subsurface flow for different mathematical descriptions (i.e. the Darcy-Weisbach equation vs. the diffusive wave and kinematic wave equation). For this study, the model will also be evaluated for hillslopes in three different geological settings within the Attert Basin in Luxembourg.

  1. Development of a 1D canopy module to couple mesoscale meteorogical model with building energy model

    NASA Astrophysics Data System (ADS)

    Mauree, Dasaraden; Kohler, Manon; Blond, Nadège; Clappier, Alain

    2013-04-01

    The actual global warming, highlighted by the scientific community, is due to the greenhouse gases emissions resulting from our energy consumption. This energy is mainly produced in cities (about 70% of the total energy use). Around 36% of this energy are used in buildings (residential/tertiary) and this accounts for about 20% of the greenhouse gases emissions. Moreover, the world population is more and more concentrated in urban areas, 50% of the actual world population already lives in cities and this ratio is expected to reach 70% by 2050. With the obviously increasing responsibility of cities in climate change in the future, it is of great importance to go toward more sustainable cities that would reduce the energy consumption in urban areas. The energy use inside buildings is driven by two factors: (1) the level of comfort wished by the inhabitants and (2) the urban climate. On the other hand, the urban climate is influenced by the presence of buildings. Indeed, artificial surfaces of urban areas modify the energy budget of the Earth's surface and furthermore, heat is released into the atmosphere due to the energy used by buildings. Modifications at the building scale (micro-scale) can thus have an influence on the climate of the urban areas and surroundings (meso-scale), and vice and versa. During the last decades, meso-scale models have been developed to simulate the atmospheric conditions for domain of 100-1000km wide with a resolution of few kilometers. Due to their low resolution, the effects of small obstacles (such as buildings, trees, ...) near the ground are not reproduced properly and parameterizations have been developed to represent such effects in meso-scale models. On the other side, micro-scale models have a higher resolution (around 1 meter) and consequently can better simulate the impact of obstacles on the atmospheric heat flux exchanges with the earth surface. However, only a smaller domain (less than 1km) can be simulated for the same

  2. Regional Model Nesting Within GFS Daily Forecasts Over West Africa

    NASA Technical Reports Server (NTRS)

    Druyan, Leonard M.; Fulakeza, Matthew; Lonergan, Patrick; Worrell, Ruben

    2010-01-01

    The study uses the RM3, the regional climate model at the Center for Climate Systems Research of Columbia University and the NASA/Goddard Institute for Space Studies (CCSR/GISS). The paper evaluates 30 48-hour RM3 weather forecasts over West Africa during September 2006 made on a 0.5 grid nested within 1 Global Forecast System (GFS) global forecasts. September 2006 was the Special Observing Period #3 of the African Monsoon Multidisciplinary Analysis (AMMA). Archived GFS initial conditions and lateral boundary conditions for the simulations from the US National Weather Service, National Oceanographic and Atmospheric Administration were interpolated four times daily. Results for precipitation forecasts are validated against Tropical Rainfall Measurement Mission (TRMM) satellite estimates and data from the Famine Early Warning System (FEWS), which includes rain gauge measurements, and forecasts of circulation are compared to reanalysis 2. Performance statistics for the precipitation forecasts include bias, root-mean-square errors and spatial correlation coefficients. The nested regional model forecasts are compared to GFS forecasts to gauge whether nesting provides additional realistic information. They are also compared to RM3 simulations driven by reanalysis 2, representing high potential skill forecasts, to gauge the sensitivity of results to lateral boundary conditions. Nested RM3/GFS forecasts generate excessive moisture advection toward West Africa, which in turn causes prodigious amounts of model precipitation. This problem is corrected by empirical adjustments in the preparation of lateral boundary conditions and initial conditions. The resulting modified simulations improve on the GFS precipitation forecasts, achieving time-space correlations with TRMM of 0.77 on the first day and 0.63 on the second day. One realtime RM3/GFS precipitation forecast made at and posted by the African Centre of Meteorological Application for Development (ACMAD) in Niamey, Niger

  3. Detection of mesoscale zones of atmospheric instabilities using remote sensing and weather forecasting model data

    NASA Astrophysics Data System (ADS)

    Winnicki, I.; Jasinski, J.; Kroszczynski, K.; Pietrek, S.

    2009-04-01

    The paper presents elements of research conducted in the Faculty of Civil Engineering and Geodesy of the Military University of Technology, Warsaw, Poland, concerning application of mesoscale models and remote sensing data to determining meteorological conditions of aircraft flight directly related with atmospheric instabilities. The quality of meteorological support of aviation depends on prompt and effective forecasting of weather conditions changes. The paper presents a computer module for detecting and monitoring zones of cloud cover, precipitation and turbulence along the aircraft flight route. It consists of programs and scripts for managing, processing and visualizing meteorological and remote sensing databases. The application was developed in Matlab® for Windows®. The module uses products of COAMPS (Coupled Ocean/Atmosphere Mesoscale Prediction System) mesoscale non-hydrostatic model of the atmosphere developed by the US Naval Research Laboratory, satellite images acquisition system from the MSG-2 (Meteosat Second Generation) of the European Organization for the Exploitation of Meteorological Satellites (EUMETSAT) and meteorological radars data acquired from the Institute of Meteorology and Water Management (IMGW), Warsaw, Poland. The satellite images acquisition system and the COAMPS model are run operationally in the Faculty of Civil Engineering and Geodesy. The mesoscale model is run on an IA64 Feniks multiprocessor 64-bit computer cluster. The basic task of the module is to enable a complex analysis of data sets of miscellaneous information structure and to verify COAMPS results using satellite and radar data. The research is conducted using uniform cartographic projection of all elements of the database. Satellite and radar images are transformed into the Lambert Conformal projection of COAMPS. This facilitates simultaneous interpretation and supports decision making process for safe execution of flights. Forecasts are based on horizontal

  4. Propagation of Impact-Induced Shock Waves in Heterogenous Rocks Using Mesoscale Modeling

    NASA Astrophysics Data System (ADS)

    Güldemeister, N.; Durr, N.; Wünnemann, K.; Elbeshausen, D.; Hiermaier, S.

    2011-03-01

    In the framework of the “MEMIN” project, the effect of porosity in dry and water-saturated sandstone on shock wave loading is investigated. We conducted a series of numerical experiments of shock wave propagation in porous material using macro- as well as mesoscale models.

  5. Evaluation of a Mesoscale Atmospheric Dispersion Modeling System with Observations from the 1980 Great Plains Mesoscale Tracer Field Experiment. Part II: Dispersion Simulations.

    NASA Astrophysics Data System (ADS)

    Moran, Michael D.; Piekle, Roger A.

    1996-03-01

    The Colorado State University mesoscale atmospheric dispersion (MAD) numerical modeling system, which consists of a prognostic mesoscale meteorological model coupled to a mesoscale Lagrangian particle dispersion model (MLPDM), has been used to simulate the emission, transport, and diffusion of a perfluorocarbon tracer-gas cloud for one afternoon surface release during the July 1980 Great Plains mesoscale tracer field experiment. The MLPDM was run for a baseline simulation and seven sensitivity experiments. The baseline simulation showed considerable skill in predicting such quantitative whole-could characteristics as peak ground-level concentration (GLC), maximum cloud width, cloud arrival and transit times, and crosswind integrated exposure at downwind distances of both 100 and 60 km. The baseline simulation also compared very favorably to simulations made by seven other MAD models for this same case in an earlier study. The sensitivity experiments explored the impact of various factors on MAD, especially the diurnal heating cycle and physiographic and atmospheric inhomogeneities, by including or excluding them in different combinations. The GLC `footprints' predicted in the sensitivity experiments were sensitive to differences in the simulated meteorological fields.The observations and the numerical simulations both suggest that the Great Plains nocturnal low-level jet played an important role in transporting and deforming the perfluorocarbon tracer cloud during this MAD experiment: the mean transport speed was supergeostrophic and both crosswind and alongwind cloud spreads were larger than can be explained by turbulent diffusion alone. The contributions of differential horizontal advection and mesoscale deformation to MAD dominate those of small-scale turbulent diffusion for this case, and Pasquill's delayed-shear enhancement mechanism for horizontal diffusion appears to have played a significant role during nighttime transport. These results demonstrate the

  6. Evaluation of a mesoscale atmospheric dispersion modeling system with observations from the 1980 Great Plains mesoscale tracer field experiment. Part I: Datasets and meterological simulations

    SciTech Connect

    Moran, M.D.; Pielke, R.A.

    1996-03-01

    A mesoscale atmospheric dispersion (MAD) numerical modeling system, consisting of a mesoscale meteorological model coupled to a mesoscale Lagrangian particle dispersion model, was used to simulate transport and diffusion of a perfluorocarbon tracer-gas cloud for a surface release during the July 1980 Great Plains mesoscale tracer field experiment. Ground-level concentration (GLC) measurements taken downwind of the release site up to three days after the tracer release were available for comparison. Quantitative measures of significant dispersion characteristics obtained from analysis of the tracer cloud`s moving GLC {open_quotes}footprint{close_quotes} were used to evaluate the simulation of the MAD case. MAD is more dependent on the spatial and temporal structure of the transport wind field than is short-range atmospheric dispersion. For the tracer experiment, the observations suggest that the nocturnal low-level jet played an important role in transporting and deforming the tracer cloud. Ten two- and three-dimensional numerical meteorological experiments were devised to investigate the relative contributions of topography, other surface inhomogeneities, atmospheric baroclinicity, synoptic-scale flow evolution, and meteorological model initialization time to the structure and evolution of the low-level mesoscale flow field and thus to MAD. Results from the meteorological simulations are compared in this paper. The predicted wind fields display significant differences, which give rise in turn to significant differences in predicted low-level transport. The presence of an oscillatory ageostrophic component in the observed synoptic low-level winds for this case is shown to complicate initialization of the meteorological model considerably and is the likely cause of directional errors in the predicted mean tracer transport. A companion paper describes the results from the associated dispersion simulations. 76 refs., 13 figs., 6 tabs.

  7. A nested multisite daily rainfall stochastic generation model

    NASA Astrophysics Data System (ADS)

    Srikanthan, Ratnasingham; Pegram, Geoffrey G. S.

    2009-06-01

    SummaryThis paper describes a nested multisite daily rainfall generation model which preserves the statistics at daily, monthly and annual levels of aggregation. A multisite two-part daily model is nested in multisite monthly, then annual models. A multivariate set of fourth order Markov chains is used to model the daily occurrence of rainfall; the daily spatial correlation in the occurrence process is handled by using suitably correlated uniformly distributed variates via a Normal Scores Transform (NST) obtained from a set of matched multinormal pseudo-random variates, following Wilks [Wilks, D.S., 1998. Multisite generalisation of a daily stochastic precipitation generation model. Journal of Hydrology 210, 178-191]; we call it a hidden covariance model. A spatially correlated two parameter gamma distribution is used to obtain the rainfall depths; these values are also correlated via a specially matched hidden multinormal process. For nesting, the generated daily rainfall sequences at all the sites are aggregated to monthly rainfall values and these values are modified by a set of lag-1 autoregressive multisite monthly rainfall models. The modified monthly rainfall values are aggregated to annual rainfall and these are then modified by a lag-1 autoregressive multisite annual model. This nesting process ensures that the daily, monthly and annual means and covariances are preserved. The model was applied to a region with 30 rainfall sites, one of the five sets reported by Srikanthan [Srikanthan, R., 2005. Stochastic Generation of Daily Rainfall Data at a Number of Sites. Technical Report 05/7, CRC for Catchment Hydrology. Monash University, 66p]. A comparison of the historical and generated statistics shows that the model preserves all the important characteristics of rainfall at the daily, monthly and annual time scales, including the spatial structure. There are some outstanding features that need to be improved: depths of rainfall on isolated wet days and

  8. Impact of Submesoscale Eddies on Synoptic and Mesoscale Oceanic Structures in a Continental Shelf Margin Analyzed with a Downscaling Ocean Model of Japan Sea

    NASA Astrophysics Data System (ADS)

    Miyazaki, D.; Uchiyama, Y.; Kanki, R.; Miyazawa, Y.

    2014-12-01

    Japan Sea (JPS) is connected to other seas by five narrow and shallow straits with a minimal depth of the order of 100 meters or less, resulting in limited water exchange thereby isolating the water and aquatic ecosystem. The modeling and observational studies on quantifying the dynamics of JPS are still undergoing (e.g., Hirose et al., 2007), whereas effects of submesoscale dynamics on the mean structure, eddies, and material dispersal in JPS have not been extensively investigated yet. In the present study, we conduct a detailed oceanic downscaling numerical experiment using ROMS in a double nested configuration bounded on the assimilative JCOPE2 (Miyazawa et al., 2009) reanalysis at horizontal resolutions of 3 km (ROMS-L1) and 1 km (ROMS-L2). The L1 and L2 models are compared to the observed data to show a good agreement with an appropriate parameter choice. Our models sufficiently reproduce the overall frontal structure and associated major currents in JPS consisting of the Liman Cold Current along the Russian coast and the Tsushima Warm Current along the Japanese coast. Surface normalized relative vorticity fields demonstrate that both the mesoscale and submesoscale eddies are apparently enhanced, as the model grid resolution is finer. In summer and fall, mesoscale eddies are evident in L1 and L2. In contrast in winter and spring, submesoscale eddies are significantly energized in the whole JPS particularly in L2 due to the surface cooling that preconditions symmetric instability (e.g., Thomas et al., 2012). The enhancement of EKE appears around Tsushima strait and along the Korean Peninsula in L1, while EKE in L2 is extensively increased in the most part of the southern JPS. On the other hand, a SSH variance, a proxy of mesoscale variability, is more realistically distributed in L2 than L1, suggesting a potential importance of submesoscale eddies on the mesoscale dynamics.

  9. High-Resolution Specification of the Land and Ocean Surface for Improving Regional Mesoscale Model Predictions

    NASA Technical Reports Server (NTRS)

    Case, Jonathan L.; Lazarus, Steven M.; Splitt, Michael E.; Crosson, William L.; Lapenta, William M.; Jedlovec, Gary J.; Peters-Lidard, Christa D.

    2008-01-01

    The exchange of energy and moisture between the Earth's surface and the atmospheric boundary layer plays a critical role in many meteorological processes. High-resolution, accurate representations of surface properties such as sea-surface temperature (SST), soil temperature and moisture content, ground fluxes, and vegetation are necessary to better understand the Earth-atmosphere interactions and improve numerical predictions of sensible weather. The NASA Short-term Prediction Research and Transition (SPoRT) Center has been conducting separate studies to examine the impacts of high-resolution land-surface initialization data from the Goddard Space Flight Center Land Information System (LIS) on subsequent WRF forecasts, as well as the influence of initializing WRF with SST composites derived from the MODIS instrument. This current project addresses the combined impacts of using high-resolution lower boundary data over both land (LIS data) and water (MODIS SSTs) on the subsequent daily WRF forecasts over Florida during May 2004. For this experiment, the WRF model is configured to run on a nested domain with 9- km and 3-kin grid spacing, centered on the Florida peninsula and adjacent coastal waters of the Gulf of Mexico and Atlantic Ocean. A control configuration of WRF is established to take all initial condition data from the NCEP Eta model. Meanwhile, two WRF experimental runs are configured to use high-resolution initialization data from (1) LIS land-surface data only, and (2) a combination of LIS data and high-resolution MODIS SST composites. The experiment involves running 24-hour simulations of the control WRF configuration, the MS-initialized WRF, and the LIS+MODIS-initialized WRF daily for the entire month of May 2004. All atmospheric data for initial and boundary conditions for the Control, LIS, and LIS+MODIS runs come from the NCEP Eta model on a 40-km grid. Verification statistics are generated at land surface observation sites and buoys, and the impacts

  10. Simultaneous Nested Modeling from the Synoptic Scale to the LES Scale

    NASA Astrophysics Data System (ADS)

    Liu, Y.; Wu, W.; Gregory, G.; Warner, T.; Swerdlin, S.

    2009-04-01

    Many applications require accurate weather information over broad temporal and spatial scales. For example, wind energy prediction requires regional weather forecasting to cope with intra-hour, multi-hour and day ahead decision-making. In addition, microscale modeling is needed to support wind turbine sitting decisions and turbine operations. In the last 10 years, the National Center for Atmospheric Research, US, has developed a Real-Time Four-Dimensional Data Assimilation (RTFDDA) and forecasting system to support diverse weather-critical applications such as wind energy forecasting. RTFDDA, built upon the Weather Research and Forecasting (WRF) model, is a rapid-cycling, multi-scale weather system with a capability for effectively combining all available weather observations with the full-physics WRF model to produce high-accuracy multi-scale 4D weather information from synoptic scales (~2000 km), to mesoscales (2 - 2000 km), and to microscales (< 2 km). RTFDDA performs successive downscaling from synoptic numerical weather predictions (based on global models), to regional weather predictions (mesoscale weather processes), and to small and microscale weather modeling with Large Eddy Simulation (LES). Two real weather cases with typical strong local forcing phenomena, one with an isolated elongated bell-shaped mountain in central Utah and the other with complex coastlines along the Chesapeake Bay, Maryland, were simulated using the WRF-RTFDDA-LES system with six nested domains having grid sizes of 30, 10, 3.333, 1.111, 0.369 and 0.123 km. The NASA SRTM (Shuttle Radar-sensing Topography Mission) 30-m resolution terrain heights were used to specify the fine mesh model terrain and to adjust fine-scale coastlines. Both cases were run for 24+ hours to span the diurnal evolution of local weather. Analysis of the model results indicates an encouraging downscaling capability of the modeling system in simulating the high-resolution underlying forcing and interaction with

  11. ROCKY MOUNTAIN ACID DEPOSITION MODEL ASSESSMENT: EVALUATION OF MESOSCALE ACID DEPOSITION MODELS FOR USE IN COMPLEX TERRAIN

    EPA Science Inventory

    The report includes an evaluation of candidate meteorological models and acid deposition models. The hybrid acid deposition/air quality modeling system for the Rocky Mountains makes use of a mesoscale meteorological model, which includes a new diagnostic wind model, as a driver f...

  12. A cumulus parameterization scheme designed for nested grid meso-{beta} scale models

    SciTech Connect

    Weissbluth, M.J.; Cotton, W.R.

    1991-12-31

    A generalized cumulus parameterization based upon higher order turbulence closure has been incorporated into one dimensional simulations. The scheme consists of a level 2.5w turbulence closure scheme mated with a convective adjustment scheme. The convective adjustment scheme includes a gradient term which can be interpreted as either a subsidence term when the scheme is used in large scale models or a mesoscale compensation term when the scheme is used in mesoscale models. The scheme also includes a convective adjustment term which is interpreted as a detrainment term in large scale models. In mesoscale models, the mesoscale compensation term and the advection by the mean vertical motions combine to yield no net advection which is desirable since the convective moistening and heating is now wholly accomplished by the convective adjustment term; double counting is then explicitly eliminated. One dimensional simulations indicate satisfactory performance of the cumulus parameterization scheme for a non-entraining updraft.

  13. A cumulus parameterization scheme designed for nested grid meso-. beta. scale models

    SciTech Connect

    Weissbluth, M.J.; Cotton, W.R.

    1991-01-01

    A generalized cumulus parameterization based upon higher order turbulence closure has been incorporated into one dimensional simulations. The scheme consists of a level 2.5w turbulence closure scheme mated with a convective adjustment scheme. The convective adjustment scheme includes a gradient term which can be interpreted as either a subsidence term when the scheme is used in large scale models or a mesoscale compensation term when the scheme is used in mesoscale models. The scheme also includes a convective adjustment term which is interpreted as a detrainment term in large scale models. In mesoscale models, the mesoscale compensation term and the advection by the mean vertical motions combine to yield no net advection which is desirable since the convective moistening and heating is now wholly accomplished by the convective adjustment term; double counting is then explicitly eliminated. One dimensional simulations indicate satisfactory performance of the cumulus parameterization scheme for a non-entraining updraft.

  14. Modified finite-element model for application to terrain-induced mesoscale flows

    SciTech Connect

    Lee, R.L.; Leone, J.M. Jr.; Gresho, P.M.

    1982-11-01

    Terrain-induced mesoscale flows are localized atmospheric motions generated primarily by surface inhomogeneities such as differential heating and irregular terrain. Well-known examples of such flows are sea-and-land breeze circulations, mountain-valley flows, urban heat island circulations and mountain lee waves. A numerical model capable of capturing the details of these frequently complicated flow patterns must often contain a realistic and rather accurate representation of the relevant terrain. Over the last decade, mesoscale models have been developed in which various approaches were used to incorporate variable terrain. In this study, a somewhat unique approach, based on a modified finite element procedure, was used to solve the nonhydrostatic planetary boundary layer equations. The nonhydrostatic and finite element features of the model are particularly advantageous for modeling flows over complex topography. The numerical aspects of the model, the parameterizations currently used, and a few preliminary results are presented.

  15. Procedures for offline grid nesting in regional ocean models

    NASA Astrophysics Data System (ADS)

    Mason, Evan; Molemaker, Jeroen; Shchepetkin, Alexander F.; Colas, Francois; McWilliams, James C.; Sangrà, Pablo

    One-way offline nesting of a primitive-equation regional ocean numerical model (ROMS) is investigated, with special attention to the boundary forcing file creation process. The model has a modified open boundary condition which minimises false wave reflections, and is optimised to utilise high-frequency boundary updates. The model configuration features a previously computed solution which supplies boundary forcing data to an interior domain with an increased grid resolution. At the open boundaries of the interior grid (the child) the topography is matched to that of the outer grid (the parent), over a narrow transition region. A correction is applied to the normal baroclinic and barotropic velocities at the open boundaries of the child to ensure volume conservation. It is shown that these steps, together with a carefully constructed interpolation of the parent data, lead to a high-quality child solution, with minimal artifacts such as persistent rim currents and wave reflections at the boundaries. Sensitivity experiments provide information about the robustness of the model open boundary condition to perturbations in the surface wind stress forcing field, to the perturbation of the volume conservation enforcement in the boundary forcing, and to perturbation of the vertical density structure in the boundary forcing. This knowledge is important when extending the nesting technique to include external data from alien sources, such as ocean models with physics and/or numerics different from ROMS, or from observed climatologies of temperature, salinity and sea level.

  16. Urban morphological analysis for mesoscale meteorological and dispersion modeling applications : current issues

    SciTech Connect

    Burian, S. J.; Brown, M. J.; Ching, J.; Cheuk, M. L.; Yuan, M.; McKinnon, A. T.; Han, W. S.

    2004-01-01

    Accurate predictions of air quality and atmospheric dispersion at high spatial resolution rely on high fidelity predictions of mesoscale meteorological fields that govern transport and turbulence in urban areas. However, mesoscale meteorological models do not have the spatial resolution to directly simulate the fluid dynamics and thermodynamics in and around buildings and other urban structures that have been shown to modify micro- and mesoscale flow fields (e.g., see review by Bornstein 1987). Mesoscale models therefore have been adapted using numerous approaches to incorporate urban effects into the simulations (e.g., see reviews by Brown 2000 and Bornstein and Craig 2002). One approach is to introduce urban canopy parameterizations to approximate the drag, turbulence production, heating, and radiation attenuation induced by sub-grid scale buildings and urban surface covers (Brown 2000). Preliminary results of mesoscale meteorological and air quality simulations for Houston (Dupont et al. 2004) demonstrated the importance of introducing urban canopy parameterizations to produce results with high spatial resolution that accentuates variability, highlights important differences, and identifies critical areas. Although urban canopy parameterizations may not be applicable to all meteorological and dispersion models, they have been successfully introduced and demonstrated in many of the current operational and research mode mesoscale models, e.g., COAMPS (Holt et al. 2002), HOTMAC (Brown and Williams 1998), MM5 (e.g., Otte and Lacser 2001; Lacser and Otte 2002; Dupont et al. 2004), and RAMS (Rozoff et al. 2003). The primary consequence of implementing an urban parameterization in a mesoscale meteorological model is the need to characterize the urban terrain in greater detail. In general, urban terrain characterization for mesoscale modeling may be described as the process of collecting datasets of urban surface cover physical properties (e.g., albedo, emissivity) and

  17. Mesoscale modelling of water vapour in the tropical UTLS: two case studies from the HIBISCUS campaign

    NASA Astrophysics Data System (ADS)

    Marécal, V.; Durry, G.; Longo, K.; Freitas, S.; Rivière, E. D.; Pirre, M.

    2007-03-01

    In this study, we evaluate the ability of the BRAMS (Brazilian Regional Atmospheric Modeling System) mesoscale model compared to ECMWF global analysis to simulate the observed vertical variations of water vapour in the tropical upper troposphere and lower stratosphere (UTLS). The observations are balloon-borne measurements of water vapour mixing ratio and temperature from micro-SDLA (Tunable Diode Laser Spectrometer) instrument. Data from two balloon flights performed during the 2004 HIBISCUS field campaign are used to compare with the mesoscale simulations and to the ECMWF analysis. The observations exhibit fine scale vertical structures of water vapour of a few hundred meters height. The ECMWF vertical resolution (~1 km) is too coarse to capture these vertical structures in the UTLS. With a vertical resolution similar to ECMWF, the mesoscale model performs better than ECMWF analysis for water vapour in the upper troposphere and similarly or slightly worse for temperature. The BRAMS model with 250 m vertical resolution is able to capture more of the observed fine scale vertical variations of water vapour compared to runs with a coarser vertical resolution. This is mainly related to: (i) the enhanced vertical resolution in the UTLS and (ii) to the more detailed microphysical parameterization providing ice supersaturations as in the observations. In near saturated or supersaturated layers, the mesoscale model predicted relative humidity with respect to ice saturation is close to observations provided that the temperature profile is realistic. For temperature, the ECMWF analysis gives good results partly attributed to data assimilation. The analysis of the mesoscale model results showed that the vertical variations of the water vapour profile depends on the dynamics in unsaturated layer while the microphysical processes play a major role in saturated/supersaturated layers. In the lower stratosphere, the ECMWF model and the BRAMS model give very similar water vapour

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

    SciTech Connect

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

    2014-06-01

    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.

  19. The effects of elevation data representation on mesoscale atmospheric model simulations

    SciTech Connect

    Walker, H.; Leone, J.M. Jr.; Kim, Jinwon

    1996-01-01

    Mesoscale atmospheric model simulations rely on descriptions of the land surface characteristics, which must be developed from geographic databases. Certain features of the geographic data, such as its resolution and accuracy, as well as the method of processing for use in the model, can be very important in producing accurate model simulations. The work described here is part of research effort into the relationship between these aspects of geographic data and the performance of mesoscale atmospheric models and is particularly focused on elevation data and how it is prepared for use in such models. A source for digital elevation data will typically not be at the resolution required for a given model simulation and so a resampling step is required. In addition, predictive non-linear model often cannot accept forcing at high spatial frequencies due to the terrain, thus smoothing is also required. The effect of different means of resampling and smoothing elevation data on two types of model simulations is investigated. At smaller spatial scales, nocturnal drainage winds in mountain valleys in Colorado are examined for effects on the general characteristics as well as the details of the flows. At the larger end of the mesoscale, extended simulations of California weather are examined for effects on orographic lifting, low-level convergence and divergence and ultimately rain and snow distribution.

  20. A four-dimensional, mesoscale, non-gaussian multispectral smoke model. Phase 1: Feasibility study

    NASA Astrophysics Data System (ADS)

    Yamartino, R. J.; Strimaitis, D. G.; Scire, J. S.; Insley, E. M.

    1992-12-01

    The feasibility of developing a four-dimensional, non-Gaussian mesoscale multispectral smoke model that could run on a personal computer is investigated. Several of the model components are formulated, coded, and tested. This included the main driver program for accessing and interpolating the mesoscale winds and generating particle trajectories, a sub-grid-scale velocity field generator based on the kinematic simulation approach, and a dry deposition model for particle deposition velocities. Current understanding of flow and turbulence modeling is reviewed and can be applied to developing appropriate kinematic simulation fields. Technical approaches to account for the height and particle size dependent probability of particle removal and to compute the point and path average particle concentrations are also presented. Conclusions and recommendations for future work are included.

  1. Ellipsoidal nested sampling, expression of the model uncertainty and measurement

    NASA Astrophysics Data System (ADS)

    Palmisano, C.; Mana, G.; Gervino, G.

    2015-07-01

    The measurand value, the conclusions, and the decisions inferred from measurements may depend on the models used to explain and to analyze the results. In this paper, the problems of identifying the most appropriate model and of assessing the model contribution to the uncertainty are formulated and solved in terms of Bayesian model selection and model averaging. As computational cost of this approach increases with the dimensionality of the problem, a numerical strategy, based on multimodal ellipsoidal nested sampling, to integrate over the nuisance parameters and to compute the measurand post-data distribution is outlined. In order to illustrate the numerical strategy, by use of MATHEMATICA an elementary example concerning a bimodal, two-dimensional distribution has also been studied.

  2. Studying PMMA films on silica surfaces with generic microscopic and mesoscale models

    NASA Astrophysics Data System (ADS)

    Zhang, J.; Mukherji, D.; Daoulas, K. Ch.

    2016-07-01

    Polymer films on solid substrates present significant interest for fundamental polymer physics and industrial applications. For their mesoscale study, we develop a hybrid particle-based representation where polymers are modeled as worm-like chains and non-bonded interactions are introduced through a simple density functional. The mesoscale description is parameterized to match a generic microscopic model, which nevertheless can represent real materials. Choosing poly (methyl methacrylate) adsorbed on silica as a case study, the consistency of both models in describing conformational and structural properties in polymer films is investigated. We compare selected quantifiers of chain-shape, the structure of the adsorbed layer, as well as the statistics of loops, tails, and trains. Overall, the models are found to be consistent with each other. Some deviations in conformations and structure of adsorbed layer can be attributed to the simplified description of polymer/surface interactions and local liquid packing in the mesoscale model. These results are encouraging for a future development of pseudo-dynamical schemes, parameterizing the kinetics in the hybrid model via the dynamics of the generic microscopic model.

  3. MESO-SCALE MODELING OF THE INFLUENCE OF INTERGRANULAR GAS BUBBLES ON EFFECTIVE THERMAL CONDUCTIVITY

    SciTech Connect

    Paul C. Millett; Michael Tonks

    2011-06-01

    Using a mesoscale modeling approach, we have investigated how intergranular fission gas bubbles, as observed in high-burnup nuclear fuel, modify the effective thermal conductivity in a polycrystalline material. The calculations reveal that intergranular porosity has a significantly higher resistance to heat transfer compared to randomly-distributed porosity. A model is developed to describe this conductivity reduction that considers an effective grain boundary Kapitza resistance as a function of the fractional coverage of grain boundaries by bubbles.

  4. A Distributed Hydrological model Forced by DIMP2 Data and the WRF Mesoscale model

    NASA Astrophysics Data System (ADS)

    Wayand, N. E.

    2010-12-01

    Forecasted warming over the next century will drastically reduce seasonal snowpack that provides 40% of the world’s drinking water. With increased climate warming, droughts may occur more frequently, which will increase society’s reliance on this same summer snowpack as a water supply. This study aims to reduce driving data errors that lead to poor simulations of snow ablation and accumulation, and streamflow. Results from the Distributed Hydrological Model Intercomparison Project Phase 2 (DMIP2) project using the Distributed Hydrology Soil and Vegetation Model (DHSVM) highlighted the critical need for accurate driving data that distributed models require. Currently, the meteorological driving data for distributed hydrological models commonly rely on interpolation techniques between a network of observational stations, as well as historical monthly means. This method is limited by two significant issues: snowpack is stored at high elevations, where interpolation techniques perform poorly due to sparse observations, and historic climatological means may be unsuitable in a changing climate. Mesoscale models may provide a physically-based approach to supplement surface observations over high-elevation terrain. Initial results have shown that while temperature lapse rates are well represented by multiple mesoscale models, significant precipitation biases are dependent on the particular model microphysics. We evaluate multiple methods of downscaling surface variables from the Weather and Research Forecasting (WRF) model that are then used to drive DHSVM over the North Fork American River basin in California. A comparison between each downscaled driving data set and paired DHSVM results to observations will determine how much improvement in simulated streamflow and snowpack are gained at the expense of each additional degree of downscaling. Our results from DMIP2 will be used as a benchmark for the best available DHSVM run using all available observational data. The

  5. A process proof test for model concepts: Modelling the meso-scale

    NASA Astrophysics Data System (ADS)

    Hellebrand, Hugo; Müller, Christoph; Matgen, Patrick; Fenicia, Fabrizio; Savenije, Huub

    In hydrological modelling the use of detailed soil data is sometimes troublesome, since often these data are hard to obtain and, if available at all, difficult to interpret and process in a way that makes them meaningful for the model at hand. Intuitively the understanding and mapping of dominant runoff processes in the soil show high potential for improving hydrological models. In this study a labour-intensive methodology to assess dominant runoff processes is simplified in such a way that detailed soil maps are no longer needed. Nonetheless, there is an ongoing debate on how to integrate this type of information in hydrological models. In this study, dominant runoff processes (DRP) are mapped for meso-scale basins using the permeability of the substratum, land use information and the slope in a GIS. During a field campaign the processes are validated and for each DRP assumptions are made concerning their water storage capacity. The latter is done by means of combining soil data obtained during the field campaign with soil data obtained from the literature. Second, several parsimoniously parameterized conceptual hydrological models are used that incorporate certain aspects of the DRP. The result of these models are compared with a benchmark model in which the soil is represented as only one lumped parameter to test the contribution of the DRP in hydrological models. The proposed methodology is tested for 15 meso-scale river basins located in Luxembourg. The main goal of this study is to investigate if integrating dominant runoff processes, which have high information content concerning soil characteristics, with hydrological models allows the improvement of simulation results models with a view to regionalization and predictions in ungauged basins. The regionalization procedure gave no clear results. The calibration procedure and the well-mixed discharge signal of the calibration basins are considered major causes for this and it made the deconvolution of

  6. Local Bathymetry Estimation Using Variational Inverse Modeling: A Nested Approach

    NASA Astrophysics Data System (ADS)

    Almeida, T. G.; Walker, D. T.; Farquharson, G.

    2014-12-01

    Estimation of subreach river bathymetry from remotely-sensed surface velocity data is presented using variational inverse modeling applied to the 2D depth-averaged, shallow-water equations (SWEs). A nested approach is adopted to focus on obtaining an accurate estimate of bathymetry over a small region of interest within a larger complex hydrodynamic system. This approach reduces computational cost significantly. We begin by constructing a minimization problem with a cost function defined by the error between observed and estimated surface velocities, and then apply the SWEs as a constraint on the velocity field. An adjoint SWE model is developed through the use of Lagrange multipliers, converting the unconstrained minimization problem into a constrained one. The adjoint model solution is used to calculate the gradient of the cost function with respect to bathymetry. The gradient is used in a descent algorithm to determine the bathymetry that yields a surface velocity field that is a best-fit to the observational data. In this application of the algorithm, the 2D depth-averaged flow is computed within a nested framework using Delft3D-FLOW as the forward computational model. First, an outer simulation is generated using discharge rate and other measurements from USGS and NOAA, assuming a uniform bottom-friction coefficient. Then a nested, higher resolution inner model is constructed using open boundary condition data interpolated from the outer model (see figure). Riemann boundary conditions with specified tangential velocities are utilized to ensure a near seamless transition between outer and inner model results. The initial guess bathymetry matches the outer model bathymetry, and the iterative assimilation procedure is used to adjust the bathymetry only for the inner model. The observation data was collected during the ONR Rivet II field exercise for the mouth of the Columbia River near Hammond, OR. A dual beam squinted along-track-interferometric, synthetic

  7. Evaluation of a mesoscale atmospheric dispersion modeling system with observations from the 1980 Great Plains mesoscale tracer field experiment. Part II: Dispersion simulations

    SciTech Connect

    Moran, M.D.; Pielke, R.A.

    1996-03-01

    A mesoscale atmospheric dispersion (MAD) numerical modeling system, consisting of a mesoscale meteorological model coupled to a mesoscale Lagrangian particle dispersion model (MLPDM), was used to simulate the emission, transport, and diffusion of a perfluorocarbon tracer-gas cloud for a surface release during a tracer field experiment. The MLPDM was run for a baseline simulation and seven sensitivity experiments. The baseline simulation showed considerable skill in predicting peak ground-level concentration (GLC), maximum cloud width, cloud arrival and transit times, and crosswind integrated exposure at downwind distances of 100 and 600 km. The baseline simulation also compared very well to simulations made by seven other MAD models for the same case in an earlier study. The sensitivity experiments explored the impact of various factors on MAD, especially the diurnal heating cycle and physiographic and atmospheric inhomogeneities, by including or excluding them in different combinations. The GLC footprints predicted in sensitivity experiments were sensitive to differences in simulated meteorological fields. The observations and numerical simulations suggest that the nocturnal low-level jet played an important role in transporting and deforming the tracer cloud during this MAD experiment: the mean transport speed was supergeostrophic and both crosswind and alongwind cloud spreads were larger than can be explained by turbulent diffusion alone. The contributions of differential horizontal advection and mesoscale deformation to MAD dominate those of small-scale turbulent diffusion for this case, and Pasquill`s delayed-shear enhancement mechanism for horizontal diffusion appears to have played a significant role during nighttime transport. These results demonstrate the need in some flow regimes for better temporal resolution of boundary layer vertical shear in MAD models than is available from the conventional twice-daily rawinsonde network. 34 refs., 14 figs., 4 tabs.

  8. Model studies on the role of moist convection as a mechanism for interaction between the mesoscales

    NASA Technical Reports Server (NTRS)

    Waight, Kenneth T., III; Song, J. Aaron; Zack, John W.; Price, Pamela E.

    1991-01-01

    A three year research effort is described which had as its goal the development of techniques to improve the numerical prediction of cumulus convection on the meso-beta and meso-gamma scales. Two MESO models are used, the MASS (mesoscale) and TASS (cloud scale) models. The primary meteorological situation studied is the 28-29 Jun. 1986 Cooperative Huntsville Meteorological Experiment (COHMEX) study area on a day with relatively weak large scale forcing. The problem of determining where and when convection should be initiated is considered to be a major problem of current approaches. Assimilation of moisture data from satellite, radar, and surface data is shown to significantly improve mesoscale simulations. The TASS model is shown to reproduce some observed mesoscale features when initialized with 3-D observational data. Convection evolution studies center on comparison of the Kuo and Fritsch-Chappell cumulus parameterization schemes to each other, and to cloud model results. The Fritsch-Chappell scheme is found to be superior at about 30 km resolution, while the Kuo scheme does surprisingly well in simulating convection down to 10 km in cases where convergence features are well-resolved by the model grid. Results from MASS-TASS interaction experiments are presented and discussed. A discussion of the future of convective simulation is given, with the conclusion that significant progress is possible on several fronts in the next few years.

  9. An Adaptive Sequential Design for Model Discrimination and Parameter Estimation in Non-Linear Nested Models

    SciTech Connect

    Tommasi, C.; May, C.

    2010-09-30

    The DKL-optimality criterion has been recently proposed for the dual problem of model discrimination and parameter estimation, for the case of two rival models. A sequential version of the DKL-optimality criterion is herein proposed in order to discriminate and efficiently estimate more than two nested non-linear models. Our sequential method is inspired by the procedure of Biswas and Chaudhuri (2002), which is however useful only in the set up of nested linear models.

  10. Hot-spot contributions in shocked high explosives from mesoscale ignition models

    NASA Astrophysics Data System (ADS)

    Levesque, G.; Vitello, P.; Howard, W. M.

    2013-06-01

    High explosive performance and sensitivity is strongly related to the mesoscale defect densities. Bracketing the population of mesoscale hot spots that are active in the shocked ignition of explosives is important for the development of predictive reactive flow models. By coupling a multiphysics-capable hydrodynamics code (ale3d) with a chemical kinetics solver (cheetah), we can parametrically analyze different pore sizes undergoing collapse in high pressure shock conditions with evolving physical parameter fields. Implementing first-principles based decomposition kinetics, burning hot spots are monitored, and the regimes of pore sizes that contribute significantly to burnt mass faction and those that survive thermal conduction on the time scales of ignition are elucidated. Comparisons are drawn between the thermal explosion theory and the multiphysics models for the determination of nominal pore sizes that burn significantly during ignition for the explosive 1,3,5-triamino-2,4,6-trinitrobenzene.

  11. THE APPLICATION OF AN EVOLUTIONARY ALGORITHM TO THE OPTIMIZATION OF A MESOSCALE METEOROLOGICAL MODEL

    SciTech Connect

    Werth, D.; O'Steen, L.

    2008-02-11

    We show that a simple evolutionary algorithm can optimize a set of mesoscale atmospheric model parameters with respect to agreement between the mesoscale simulation and a limited set of synthetic observations. This is illustrated using the Regional Atmospheric Modeling System (RAMS). A set of 23 RAMS parameters is optimized by minimizing a cost function based on the root mean square (rms) error between the RAMS simulation and synthetic data (observations derived from a separate RAMS simulation). We find that the optimization can be efficient with relatively modest computer resources, thus operational implementation is possible. The optimization efficiency, however, is found to depend strongly on the procedure used to perturb the 'child' parameters relative to their 'parents' within the evolutionary algorithm. In addition, the meteorological variables included in the rms error and their weighting are found to be an important factor with respect to finding the global optimum.

  12. Determining agricultural land use scenarios in a mesoscale Bavarian watershed for modelling future water quality

    NASA Astrophysics Data System (ADS)

    Mehdi, B. B.; Ludwig, R.; Lehner, B.

    2012-06-01

    Land use scenarios are of primordial importance when implementing a hydrological model for the purpose of determining the future quality of water in a watershed. This paper provides the background for researching potential agricultural land use changes that may take place in a mesoscale watershed, for water quality research, and describes why studying the farm scale is important. An on-going study in Bavaria examining the local drivers of change in land use is described.

  13. Exploring the mesoscale activity in the Solomon Sea: A complementary approach with a numerical model and altimetric data

    NASA Astrophysics Data System (ADS)

    Gourdeau, L.; Verron, J.; Melet, A.; Kessler, W.; Marin, F.; Djath, B.

    2014-04-01

    The Solomon Sea is an area of high level of eddy kinetic energy (EKE), and represents a transit area for the low-latitude western boundary currents (LLWBCs) connecting the subtropics to the equatorial Pacific and playing a major role in ENSO dynamics. This study aims at documenting the surface mesoscale activity in the Solomon Sea for the first time. Our analysis is based on the joint analysis of altimetric data and outputs from a 1/12° model simulation. The highest surface EKE is observed in the northern part of the basin and extends southward to the central basin. An eddy tracking algorithm is used to document the characteristics and trajectories of coherent mesoscale vortices. Cyclonic eddies, generated in the south basin, are advected to the north by the LLWBCs before merging with stationary mesoscale structures present in the mean circulation. Anticyclonic eddies are less numerous. They are generated in the southeastern basin, propagate westward, reach the LLWBCs, and dissipate. The seasonal and interannual modulations of the mesoscale activity are well marked. At seasonal time scale, maximum (minimum) activity is in May-June (September). At interannual time scale, the mesoscale activity is particularly enhanced during La Niña conditions. If instabilities of the regional circulations seem to explain the generation of mesoscale features, the modulation of the mesoscale activity seems to be rather related with the intrusion at Solomon Strait of the surface South Equatorial Current, rather than to the LLWBCs, by modulating the horizontal and vertical shears suitable for instabilities.

  14. Simulating wind energy resources with mesoscale models: Intercomparison of state-of-the-art models over Northern Europe

    NASA Astrophysics Data System (ADS)

    Hahmann, A. N.

    2015-12-01

    Mesoscale models are increasingly being used to estimate wind conditions to identify perspective areas and sites where to develop wind farm projects. Mesoscale models are useful because they give information over extensive areas with various terrain complexities where measurements are scarce and measurement campaigns costly. Various mesoscale models and families of mesoscale models are being used, with thousands of setup options. Since long-term integrations are expensive and tedious to carry out, only limited comparisons exist. We have carried out a blind benchmarking study to evaluate the capabilities of mesoscale models used in wind energy to estimate site wind conditions: to highlight common issues on mesoscale modeling of wind conditions on sites with different characteristics, and to identify gaps and strengths of models and understand the root conditions for further evaluating uncertainties. Three experimental sites with tall mast measurements were selected: FINO3 (offshore), Høvsøre (coastal), and Cabauw (land-based). The participants were asked to provide hourly time series of wind speed and direction, temperature, etc., at various heights for 2011. The methods used were left to the choice of the participants, but they were asked for a detailed description of their model and many other parameters (e.g., horizontal and vertical resolution, model parameterizations, surface roughness length) that could be used to group the models and interpret the results of the intercomparison. The analysis of the time series includes comparison to observations, summarized with well-known measures such as biases, RMSE, correlations, and of sector-wise statistics, and the temporal spectra. The statistics were grouped by the models, their spatial resolution, forcing data, various integration methods, etc. The results show high fidelity of the various entries in simulating the wind climate at the offshore and coastal site. Over land and the statistics of other derived fields

  15. Macroscale modeling and mesoscale observations of plasma density structures in the polar cap

    SciTech Connect

    Basu, S.; Basu, S.; Sojka, J.J.; Schunk, R.W.; MacKenzie, E.

    1995-04-15

    The seasonal and UT variation of mesoscale structures (10 km - 100 m) in the central polar cap has been obtained from an analysis of 250-MHz intensity scintillation observations made at Thule, Greenland. It has been established earlier that mesoscale structures causing scintillations of satellite signals may develop at the edges of macroscale structures (several hundred km) such as discrete polar cap plasma density enhancements or patches through the gradient drift instability process. As such, the authrs examined the seasonal and UT variation of polar cap patches simulated by using the USU Time Dependent Ionospheric Model (TDIM) under conditions of southward B(sub z). A fairly remarkable similarity is found between the scintillation observations and the model predictions of patch occurrence. For instance, both the patch and scintillation occurrences are minimized during the winter solstice (northern hemisphere) between 0800-1200 UT while also having their largest seasonal intensity between 2000-2400 UT. Little UT dependence of patches and scintillations is seen at equinox with high intensity being observed throughout the day, while during local summer the intensity of macroscale patches and mesoscale irregularities are found to be a minimum at all UT. These results indicate that macroscale features in the polar cap are routinely associated with plasma instabilities giving rise to smaller scale structures and that the specific patch formation mechanism assumed in the simulation is consistent with the observations.

  16. Mesoscale modeling of combined aerosol and photo-oxidant processes in the Eastern Mediterranean

    NASA Astrophysics Data System (ADS)

    Lazaridis, M.; Spyridaki, A.; Solberg, S.; Smolík, J.; Zdímal, V.; Eleftheriadis, K.; Aleksanropoulou, V.; Hov, O.; Georgopoulos, P. G.

    2005-03-01

    Particulate matter and photo-oxidant processes in the Eastern Mediterranean have been studied using the UAM-AERO mesoscale air quality model in conjunction with the NILU-CTM regional model. Meteorological data were obtained from the RAMS prognostic meteorological model. The modeling domain includes the eastern Mediterranean area between the Greek mainland and the island of Crete. The modeling system is applied to study the atmospheric processes in three periods, i.e. 13-16 July 2000, 26-30 July 2000 and 7-14 January 2001. The spatial and temporal distributions of both gaseous and particulate matter pollutants have been extensively studied together with the identification of major emission sources in the area. The modeling results were compared with field data obtained in the same period. The objective of the current modeling work was mainly to apply the UAM-AERO mesoscale model in the eastern Mediterranean in order to assess the performed field campaigns and determine that the applied mesoscale model is fit for this purpose. Comparison of the modeling results with measured data was performed for a number of gaseous and aerosol species. The UAM-AERO model underestimates the PM10 measured concentrations during summer and winter campaigns. Discrepancies between modeled and measured data are attributed to unresolved particulate matter emissions. Particulate matter in the area is mainly composed by sulphate, sea salt and crustal materials, and with significant amounts of nitrate, ammonium and organics. During winter the particulate matter and oxidant concentrations were lower than the summer values.

  17. Mesoscale modeling of lake effect snow over Lake Erie - sensitivity to convection, microphysics and the water temperature

    NASA Astrophysics Data System (ADS)

    Theeuwes, N. E.; Steeneveld, G. J.; Krikken, F.; Holtslag, A. A. M.

    2010-03-01

    Lake effect snow is a shallow convection phenomenon during cold air advection over a relatively warm lake. A severe case of lake effect snow over Lake Erie on 24 December 2001 was studied with the MM5 and WRF mesoscale models. This particular case provided over 200 cm of snow in Buffalo (NY), caused three casualties and 10 million of material damage. Hence, the need for a reliable forecast of the lake effect snow phenomenon is evident. MM5 and WRF simulate lake effect snow successfully, although the intensity of the snowbelt is underestimated. It appears that significant differences occur between using a simple and a complex microphysics scheme. In MM5, the use of the simple-ice microphysics scheme results in the triggering of the convection much earlier in time than with the more sophisticated Reisner-Graupel-scheme. Furthermore, we find a large difference in the maximum precipitation between the different nested domains: Reisner-Graupel produces larger differences in precipitation between the domains than "simple ice". In WRF, the sophisticated Thompson microphysics scheme simulates less precipitation than the simple WSM3 scheme. Increased temperature of Lake Erie results in an exponential growth in the 24-h precipitation. Regarding the convection scheme, the updated Kain-Fritsch scheme (especially designed for shallow convection during lake effect snow), gives only slight differences in precipitation between the updated and the original scheme.

  18. Modeling the wind-fields of accidental releases by mesoscale forecasting

    SciTech Connect

    Albritton, J.R.; Lee, R.L.; Mobley, R.L.; Pace, J.C.; Hodur, R.A.; Lion, C.S.

    1997-07-01

    Modeling atmospheric releases even during fair weather can present a sever challenge to diagnostic, observed-data-driven, models. Such schemes are often handicapped by sparse input data from meteorological surface stations and soundings. Forecasting by persistence is only acceptable for a few hours and cannot predict important changes in the diurnal cycle or from synoptic evolution. Many accident scenarios are data-sparse in space and/or time. Here we describe the potential value of limited-area, mesoscale, forecast models for real-time emergency response. Simulated wind-fields will be passed to ARAC`s operational models to produce improved forecasts of dispersion following accidents.

  19. Toward an extended-geostrophic Euler-Poincare model for mesoscale oceanographic flow

    SciTech Connect

    Allen, J.S.; Newberger, P.A.; Holm, D.D.

    1998-07-01

    The authors consider the motion of a rotating, continuously stratified fluid governed by the hydrostatic primitive equations (PE). An approximate Hamiltonian (L1) model for small Rossby number {var_epsilon} is derived for application to mesoscale oceanographic flow problems. Numerical experiments involving a baroclinically unstable oceanic jet are utilized to assess the accuracy of the L1 model compared to the PE and to other approximate models, such as the quasigeostrophic (QG) and the geostrophic momentum (GM) equations. The results of the numerical experiments for moderate Rossby number flow show that the L1 model gives accurate solutions with errors substantially smaller than QG or GM.

  20. Modeling the Energy Resolution of Xenon with NEST

    NASA Astrophysics Data System (ADS)

    Uvarov, Sergey

    2013-04-01

    In addition to explaining the mean yields, NEST (the Noble Element Simulation Technique) can also address the energy resolution degrading effects in noble elements, for both electron and nuclear recoils (ER and NR). Liquid and gaseous xenon will be presented as examples. A non-binomial recombination fluctuation model will be discussed which well describes the intrinsic, supra-Poissonian resolution observed in xenon. It is combined with electric field effects, the Fano factor, and detector efforts, such as finite light collection efficiency and PMT quantum efficiency. In matters of conflicting dark matter search results observed by experiments such as XENON100 and CoGeNT, a stochastic, non-analytic, partially non-Gaussian understanding of the energy resolution for low-energy, WIMP-like nuclear recoils may be part of the solution. ER-NR discrimination can be predicted well with such an understanding.

  1. Mesoscale simulations of two model systems in biophysics: from red blood cells to DNAs

    NASA Astrophysics Data System (ADS)

    Peng, Zhangli; Chen, Yeng-Long; Lu, Huijie; Pan, Zehao; Chang, Hsueh-Chia

    2015-12-01

    Computational modeling has become increasingly important in biophysics, but the great challenge in numerical simulations due to the multiscale feature of biological systems limits the capability of modeling in making discoveries in biology. Innovative multiscale modeling approaches are desired to bridge different scales from nucleic acids and proteins to cells and tissues. Although all-atom molecular dynamics has been successfully applied in many microscale biological processes such as protein folding, it is still prohibitively expensive for studying macroscale problems such as biophysics of cells and tissues. On the other hand, continuum-based modeling has become a mature procedure for analysis and design in many engineering fields, but new insights for biological systems in the microscale are limited when molecular details are missing in continuum-based modeling. In this context, mesoscale modeling approaches such as Langevin dynamics, lattice Boltzmann method, and dissipative particle dynamics have become popular by simultaneously incorporating molecular interactions and long-range hydrodynamic interactions, providing insights to properties on longer time and length scales than molecular dynamics. In this review, we summarized several mesoscale simulation approaches for studying two model systems in biophysics: red blood cells (RBCs) and deoxyribonucleic acids (DNAs). The RBC is a model system for cell mechanics and biological membranes, while the DNA represents a model system for biopolymers. We introduced the motivations of studying these problems and presented the key features of different mesoscale methods. Furthermore, we described the latest progresses in these methods and highlighted the major findings for modeling RBCs and DNAs. Finally, we also discussed the challenges and potential issues of different approaches.

  2. Utilization of satellite data in mesoscale models of severe weather

    NASA Technical Reports Server (NTRS)

    Warner, T. T.

    1983-01-01

    The impact of the diagnostic initialization of divergence on short-range precipitation forecasts produced by a model, a numerical study of a storm, collaborative modeling and diagnostic studies, and a numerical investigation of the impact of SEASAT surface wind data used in the static initialization of the North Atlantic Storm of 9-10 September 1978 are summerized.

  3. Coupled Air-ocean Nested Modeling Studies Of The Adriatic Sea

    NASA Astrophysics Data System (ADS)

    Pullen, J.; Doyle, J.; Hodur, R.; Cummings, J.

    We have conducted simulations of the Adriatic Sea using the Navy Coastal Ocean Model (NCOM), with surface forcing provided by the atmospheric component of the Coupled Ocean/Atmosphere Mesoscale Prediction System (COAMPS). Our aim is to document and investigate the response pattern of the Adriatic to the complex combined forcing of the bora winds and strong Po River run-off. Separate three- dimensional multivariate optimum interpolation (MVOI) analysis techniques are used to generate the initial conditions for both COAMPS and NCOM. First, we used a 6-km NCOM grid over the entire Mediterranean Sea, with forcing supplied by sur- face stresses from a 27-km COAMPS grid, also covering the entire Mediterranean Sea area. Both the atmospheric and ocean fields produced were part of independent 12-hour incremental data assimilation cycles over the time period of interest. The re- sulting NCOM forecasts were then used as lateral boundary conditions for a series of higher resolution (2 km) NCOM forecasts of the Adriatic Sea. In these forecasts, a set of surface stress fields from COAMPS, using a nested 4 km grid centered over the Adriatic Sea, were used to force the NCOM high-resolution ocean nest. In addition, the 2 km Adriatic Sea model is forced by observed daily river discharge values from the Po River. We have focused on the time period of winter and spring 2001 when there were several bora wind events documented by the pilot program observations taken in preparation for the fall and winter 2002-2003 Adriatic Current Experiment (ACE). In addition, we analyze results from a multi-month simulation in fall/winter 1999 to establish circu- lation patterns that may appear during the upcoming observational season. The ACE observations will include ADCP's, moored buoys, CTD sections, and radar sites. The observational programs will generate much data about the circulation of this shallow sea subjected to river floods and strong bora wind events. The main goals of our work are to

  4. Essays on pricing dynamics, price dispersion, and nested logit modelling

    NASA Astrophysics Data System (ADS)

    Verlinda, Jeremy Alan

    The body of this dissertation comprises three standalone essays, presented in three respective chapters. Chapter One explores the possibility that local market power contributes to the asymmetric relationship observed between wholesale costs and retail prices in gasoline markets. I exploit an original data set of weekly gas station prices in Southern California from September 2002 to May 2003, and take advantage of highly detailed station and local market-level characteristics to determine the extent to which spatial differentiation influences price-response asymmetry. I find that brand identity, proximity to rival stations, bundling and advertising, operation type, and local market features and demographics each influence a station's predicted asymmetric relationship between prices and wholesale costs. Chapter Two extends the existing literature on the effect of market structure on price dispersion in airline fares by modeling the effect at the disaggregate ticket level. Whereas past studies rely on aggregate measures of price dispersion such as the Gini coefficient or the standard deviation of fares, this paper estimates the entire empirical distribution of airline fares and documents how the shape of the distribution is determined by market structure. Specifically, I find that monopoly markets favor a wider distribution of fares with more mass in the tails while duopoly and competitive markets exhibit a tighter fare distribution. These findings indicate that the dispersion of airline fares may result from the efforts of airlines to practice second-degree price discrimination. Chapter Three adopts a Bayesian approach to the problem of tree structure specification in nested logit modelling, which requires a heavy computational burden in calculating marginal likelihoods. I compare two different techniques for estimating marginal likelihoods: (1) the Laplace approximation, and (2) reversible jump MCMC. I apply the techniques to both a simulated and a travel mode

  5. Comparison of Soil Hydraulic Parameterizations for Mesoscale Meteorological Models.

    NASA Astrophysics Data System (ADS)

    Braun, Frank J.; Schädler, Gerd

    2005-07-01

    Soil water contents, calculated with seven soil hydraulic parameterizations, that is, soil hydraulic functions together with the corresponding parameter sets, are compared with observational data. The parameterizations include the Campbell/Clapp-Hornberger parameterization that is often used by meteorologists and the van Genuchten/Rawls-Brakensiek parameterization that is widespread among hydrologists. The observations include soil water contents at several soil depths and atmospheric surface data; they were obtained within the Regio Klima Projekt (REKLIP) at three sites in the Rhine Valley in southern Germany and cover up to 3 yr with 10-min temporal resolution. Simulations of 48-h episodes, as well as series of daily simulations initialized anew every 24 h and covering several years, were performed with the “VEG3D” soil-vegetation model in stand-alone mode; furthermore, 48-h episodes were simulated with the model coupled to a one-dimensional atmospheric model. For the cases and soil types considered in this paper, the van Genuchten/Rawls-Brakensiek model gives the best agreement between observed and simulated soil water contents on average. Especially during episodes with medium and high soil water content, the van Genuchten/Rawls-Brakensiek model performs better than the Campbell/Clapp-Hornberger model.

  6. Numerical Weather Prediction Over Caucasus Region With Nested Grid Models

    NASA Astrophysics Data System (ADS)

    Davitashvili, Dr.; Kutaladze, Dr.; Kvatadze, Dr.

    2010-09-01

    Global atmosphere models, which describe the weather processes, give the general character of the weather but can't catch the smaller scale processes, especially local weather for the territories with compound topography. Small-scale processes such as convection often dominate the local weather, which cannot be explicitly represented in models with grid size more then 10 km. A much finer grid is required to properly simulate frontal structures and represent cumulus convection. Georgia lies to the south of the Major Caucasian Ridge and the Lesser Caucasus mountains occupy the southern part of Georgia. About 85 percent of the total land area occupies complex mountain ranges.Therefore for the territory of Georgia it is necessary to use atmosphere models with a very high resolution nested grid system taking into account main orographic features of the area. We have elaborated and configured Whether Research Forecast - Advanced Researcher Weather (WRF-ARW) model for Caucasus region considering geographical-landscape character, topography height, land use, soil type and temperature in deep layers, vegetation monthly distribution, albedo and others. Porting of WRF-ARW application to the grid was a good opportunity for running model on larger number of CPUs and storing large amount of data on the grid storage elements. On the grid WRF was compiled for both Open MP and MPI (Shared + Distributed memory) environment and WPS was compiled for serial environment using PGI (v7.1.6, MPI- version 1.2.7) on the platform Linux-x86. In searching of optimal execution time for time saving different model directory structures and storage schema was used. Simulations were performed using a set of 2 domains with horizontal grid-point resolutions of 15 and 5 km, both defined as those currently being used for operational forecasts The coarser domain is a grid of 94x102 points which covers the South Caucasus region, while the nested inner domain has a grid size of 70x70 points mainly

  7. Numerical simulations of Hurricane Bertha using a mesoscale atmospheric model

    SciTech Connect

    Buckley, R.L.

    1996-08-01

    The Regional Atmospheric Model System (RAMS) has been used to simulate Hurricane Bertha as it moved toward and onto shore during the period July 10--12, 1996. Using large-scale atmospheric data from 00 UTC, 11 July (Wednesday evening) to initialize the model, a 36-hour simulation was created for a domain centered over the Atlantic Ocean east of the Florida coast near Jacksonville. The simulated onshore impact time of the hurricane was much earlier than observed (due to the use of results from the large-scale model, which predicted early arrival). However, the movement of the hurricane center (eye) as it approached the North Carolina/South Carolina coast as simulated in RAMS was quite good. Observations revealed a northerly storm track off the South Carolina coast as it moved toward land. As it approached landfall, Hurricane Bertha turned to the north-northeast, roughly paralleling the North Carolina coast before moving inland near Wilmington. Large-scale model forecasts were unable to detect this change in advance and predicted landfall near Myrtle Beach, South Carolina; RAMS, however, correctly predicted the parallel coastal movement. For future hurricane activity in the southeast, RAMS is being configured to run in an operational model using input from the large-scale pressure data in hopes of providing more information on predicted hurricane movement and landfall location.

  8. Mesoscale models of dispersions stabilized by surfactants and colloids.

    PubMed

    van der Sman, R G M; Meinders, M B J

    2014-09-01

    In this paper we discuss and give an outlook on numerical models describing dispersions, stabilized by surfactants and colloidal particles. Examples of these dispersions are foams and emulsions. In particular, we focus on the potential of the diffuse interface models based on a free energy approach, which describe dispersions with the surface-active agent soluble in one of the bulk phases. The free energy approach renders thermodynamic consistent models with realistic sorption isotherms and adsorption kinetics. The free energy approach is attractive because of its ability to describe highly complex dispersions, such as emulsions stabilized by ionic surfactants, or surfactant mixtures and dispersions with surfactant micelles. We have classified existing numerical methods into classes, using either a Eulerian or a Lagrangian representation for fluid and for the surfactant/colloid. A Eulerian representation gives a more coarse-grained, mean field description of the surface-active agent, while a Lagrangian representation can deal with steric effects and larger complexity concerning geometry and (amphiphilic) wetting properties of colloids and surfactants. However, the similarity between the description of wetting properties of both Eulerian and Lagrangian models allows for the development of hybrid Eulerian/Lagrangian models having advantages of both representations. PMID:24980050

  9. Intercomparison of mesoscale meteorological models for precipitation forecasting

    NASA Astrophysics Data System (ADS)

    Richard, E.; Cosma, S.; Benoit, R.; Binder, P.; Buzzi, A.; Kaufmann, P.

    In the framework of the RAPHAEL EU project, a series of past heavy precipitation events has been simulated with different meteorological models. Rainfall hindcasts and forecasts have been produced by four models in use at various meteorological services or research centres of Italy, Canada, France and Switzerland. The paper is focused on the comparison of the computed precipitation fields with the available surface observations. The comparison is carried out for three meteorological situations which lead to severe flashflood over the Toce-Ticino catchment in Italy (6599 km2) or the Ammer catchment (709 km2) in Germany. The results show that all four models reproduced the occurrence of these heavy precipitation events. The accuracy of the computed precipitation appears to be more case-dependent than model-dependent. The sensitivity of the computed rainfall to the boundary conditions (hindcast v. forecast) was found to be rather weak, indicating that a flood forecasting system based upon a numerical meteo-hydrological simulation could be feasible in an operational context.

  10. Mesoscale modelling of shock initiation in HMX-based explosives

    SciTech Connect

    Swift, D. C.; Mulford, R. N. R.; Winter, R. E.; Taylor, P.; Salisbury, D. A.; Harris, E. J.

    2002-01-01

    Motivation: predictive capability Want to predict initiation, detonics and performance given: {sm_bullet} Variations in composition {sm_bullet} Variations in morphology {sm_bullet}Different loading conditions Previous work on PBX and ANFO: need physically-based model rather than just mechanical calibrations

  11. Dynamic mesoscale model of dipolar fluids via fluctuating hydrodynamics

    SciTech Connect

    Persson, Rasmus A. X.; Chu, Jhih-Wei; Voulgarakis, Nikolaos K.

    2014-11-07

    Fluctuating hydrodynamics (FHD) is a general framework of mesoscopic modeling and simulation based on conservational laws and constitutive equations of linear and nonlinear responses. However, explicit representation of electrical forces in FHD has yet to appear. In this work, we devised an Ansatz for the dynamics of dipole moment densities that is linked with the Poisson equation of the electrical potential ϕ in coupling to the other equations of FHD. The resulting ϕ-FHD equations then serve as a platform for integrating the essential forces, including electrostatics in addition to hydrodynamics, pressure-volume equation of state, surface tension, and solvent-particle interactions that govern the emergent behaviors of molecular systems at an intermediate scale. This unique merit of ϕ-FHD is illustrated by showing that the water dielectric function and ion hydration free energies in homogeneous and heterogenous systems can be captured accurately via the mesoscopic simulation. Furthermore, we show that the field variables of ϕ-FHD can be mapped from the trajectory of an all-atom molecular dynamics simulation such that model development and parametrization can be based on the information obtained at a finer-grained scale. With the aforementioned multiscale capabilities and a spatial resolution as high as 5 Å, the ϕ-FHD equations represent a useful semi-explicit solvent model for the modeling and simulation of complex systems, such as biomolecular machines and nanofluidics.

  12. Range-Specific High-resolution Mesoscale Model Setup

    NASA Technical Reports Server (NTRS)

    Watson, Leela R.

    2013-01-01

    This report summarizes the findings from an AMU task to determine the best model configuration for operational use at the ER and WFF to best predict winds, precipitation, and temperature. The AMU ran test cases in the warm and cool seasons at the ER and for the spring and fall seasons at WFF. For both the ER and WFF, the ARW core outperformed the NMM core. Results for the ER indicate that the Lin microphysical scheme and the YSU PBL scheme is the optimal model configuration for the ER. It consistently produced the best surface and upper air forecasts, while performing fairly well for the precipitation forecasts. Both the Ferrier and Lin microphysical schemes in combination with the YSU PBL scheme performed well for WFF in the spring and fall seasons. The AMU has been tasked with a follow-on modeling effort to recommended local DA and numerical forecast model design optimized for both the ER and WFF to support space launch activities. The AMU will determine the best software and type of assimilation to use, as well as determine the best grid resolution for the initialization based on spatial and temporal availability of data and the wall clock run-time of the initialization. The AMU will transition from the WRF EMS to NU-WRF, a NASA-specific version of the WRF that takes advantage of unique NASA software and datasets. 37

  13. A sensitivity study of storm cyclones with a mesoscale model

    NASA Astrophysics Data System (ADS)

    Radtke, K. S.; Tetzlaff, G.

    2003-04-01

    Extra tropical storms caused noticeable damages in the last decades. The evolution of strong cyclones is investigated by simulations with the nonhydrostatic limited area model 'Lokal Modell' (LM) of the German Weather Service (DWD). Which Conditions become important to distinguish an common cyclone from an storm-cyclone? Intense cyclones are mostly characterised by two typical large-scale features: high baroclinicity along the track of the low pressure system and a region of high equivalent potential temperature. For this purpose the observed values of the horizontal temperature gradient and the distribution of air moisture are varied and were used as forcing data, in such a way the development of storms was modified. The forcing data for the LM were generated by the global model of the DWD. Therefore data of real cyclones, such as the low Ginger, which occurred in 2000, were used. As the LM simulates only a limited area, the lateral bounds become problematic because of the manipulated forcing data. A procedure is tested, in order to prevent these problems. In this manner ensembles of storm scenarios were produced. The effects of various conditions were studied. Here in particular the changes in the surface velocity field were of interest. In the case of Ginger, an increase of the temperature gradient about 10 K causes an increasing of the maximum velocity about 3 m/s.

  14. Evaluation of Korean wind map based on mesoscale model WRF

    NASA Astrophysics Data System (ADS)

    Byon, Jaeyoung; Choi, Young-Jean; Seo, Beom-Keun

    2010-05-01

    In order to encourage wind energy industry and assessment of wind resource in Korea, we establish wind resource map using numerical model over the Korean Peninsula. The model which is used in this study is Weather Research and Forecasting (WRF) that is developed in NCAR. A high resolution topography with a 100-m resolution and a land-use data which has a 30-m resolution are implemented over the Korean environment for the improvement of lower atmosphere forecast in WRF. WRF has conducted with a 1 km resolution which is forecasted using NCEP FNL data employed as initial and boundary condition. The WRF model has run for one year for the wind map over the South Korea. The running periods that is named as typical meteorological year (TMY) is determined by statistical method. The TMY represents mean atmospheric characteristics from 1998 to 2008. Strong wind occurs in eastern, southern coastal region, and Jeju island of Korea. Wind in the Korean Peninsula blows from northwest during most of the season, but from southeast during summer. High occurrence rate of main wind direction is shown in mountainous region of inland and coastal region. The performance of the TMY results over the South Korea is validated with radiosonde observation at 80m above ground level which is wind turbine hub height. Root-mean-square-error (RMSE) shows about 3-6 m/s for wind speed and mean absolute error is about 30-50 degree for wind direction. Korean wind map will be improved continuously by data assimilation and high resolution simulation less than 1 km.

  15. High resolution numerical modeling of mesoscale island wakes and sensitivity to static topographic relief data

    NASA Astrophysics Data System (ADS)

    Nunalee, C. G.; Horváth, Á.; Basu, S.

    2015-03-01

    Recent decades have witnessed a drastic increase in the fidelity of numerical weather prediction (NWP) modeling. Currently, both research-grade and operational NWP models regularly perform simulations with horizontal grid spacings as fine as 1 km. This migration towards higher resolution potentially improves NWP model solutions by increasing the resolvability of mesoscale processes and reducing dependency on empirical physics parameterizations. However, at the same time, the accuracy of high-resolution simulations, particularly in the atmospheric boundary layer (ABL), are also sensitive to orographic forcing which can have significant variability on the same spatial scale as, or smaller than, NWP model grids. Despite this sensitivity, many high resolution atmospheric simulations do not consider uncertainty with respect to selection of static terrain height dataset. In this paper, we use the Weather Research and Forecasting (WRF) model to simulate realistic cases of lower tropospheric flow over and downstream of mountainous islands using both the default global 30 s United States Geographic Survey terrain height dataset (GTOPO30) and the 3 s Shuttle Radar Topography Mission (SRTM) terrain height dataset. Our results demonstrate cases where the differences between GTOPO30-based and SRTM-based model terrain height are significant enough to produce entirely different orographic wake mechanics, such as vortex shedding vs. no vortex shedding. These results are also compared to MODIS visible satellite imagery and highlight the importance of considering uncertain static boundary conditions when running high-resolution mesoscale models.

  16. Mesoscale modeling of shear-thinning polymer solutions.

    PubMed

    Santos de Oliveira, I S; Fitzgerald, B W; den Otter, W K; Briels, W J

    2014-03-14

    We simulate the linear and nonlinear rheology of two different viscoelastic polymer solutions, a polyisobutylene solution in pristane and an aqueous solution of hydroxypropylcellulose, using a highly coarse-grained approach known as Responsive Particle Dynamics (RaPiD) model. In RaPiD, each polymer has originally been depicted as a spherical particle with the effects of the eliminated degrees of freedom accounted for by an appropriate free energy and transient pairwise forces. Motivated by the inability of this spherical particle representation to entirely capture the nonlinear rheology of both fluids, we extended the RaPiD model by introducing a deformable particle capable of elongation. A Finite-Extensible Non-Linear Elastic potential provides a free energy penalty for particle elongation. Upon disentangling, this deformability allows more time for particles to re-entangle with neighbouring particles. We show this process to be integral towards recovering the experimental nonlinear rheology, obtaining excellent agreement. We show that the nonlinear rheology is crucially dependent upon the maximum elongation and less so on the elasticity of the particles. In addition, the description of the linear rheology has been retained in the process. PMID:24628201

  17. MESOSCALE MODELLING OF SHOCK INITIATION IN HMX-BASED EXPLOSIVES

    SciTech Connect

    Mulford, R. N. R.; Swift, D. C.

    2001-01-01

    Hydrocode calculations we used to simulate initiation in single- and double-shock experiments on several HMX-based explosives. Variations in the reactive behavior of theee materials reflects the differences between binders in the material, providing information regarding the sensitivity of the explosive to the mechanical properties of the constituents. Materials considered are EDC-37, with a soft binder, PBX-9601, with a relatively malleable binder, and PIBX-9404, with a stiff binder. Bulk reactive behavior of these materials is dominated by the HMX component and should be comparable, while the mechanical response varies. The reactive flow model is temperature-dependent, based on a modified Arrhenius rate. Some unreacted material is allowed to react at a rate given by the state of the hotspot rather than the bulk state of the unreacted explosive, according to a length scale reflecting the hotspot size, and a time scale for thermal equilibration. The Arrhenius rate for HMX is wsumed to be the same for all compositions. The initiation data for different HMX-bwd explosives axe modelled by choosing plausible parameters to describe the reactive and dissipative properties of the binder, and hence the behavior of the hotspots in each formulation.

  18. Mesoscale modeling of shear-thinning polymer solutions

    NASA Astrophysics Data System (ADS)

    Santos de Oliveira, I. S.; Fitzgerald, B. W.; den Otter, W. K.; Briels, W. J.

    2014-03-01

    We simulate the linear and nonlinear rheology of two different viscoelastic polymer solutions, a polyisobutylene solution in pristane and an aqueous solution of hydroxypropylcellulose, using a highly coarse-grained approach known as Responsive Particle Dynamics (RaPiD) model. In RaPiD, each polymer has originally been depicted as a spherical particle with the effects of the eliminated degrees of freedom accounted for by an appropriate free energy and transient pairwise forces. Motivated by the inability of this spherical particle representation to entirely capture the nonlinear rheology of both fluids, we extended the RaPiD model by introducing a deformable particle capable of elongation. A Finite-Extensible Non-Linear Elastic potential provides a free energy penalty for particle elongation. Upon disentangling, this deformability allows more time for particles to re-entangle with neighbouring particles. We show this process to be integral towards recovering the experimental nonlinear rheology, obtaining excellent agreement. We show that the nonlinear rheology is crucially dependent upon the maximum elongation and less so on the elasticity of the particles. In addition, the description of the linear rheology has been retained in the process.

  19. Mesoscale to plant-scale models of nuclear waste reprocessing.

    SciTech Connect

    Noble, David Frederick; O'Hern, Timothy John; Moffat, Harry K.; Nemer, Martin B.; Domino, Stefan Paul; Rao, Rekha Ranjana; Cipiti, Benjamin B.; Brotherton, Christopher M.; Jove-Colon, Carlos F.; Pawlowski, Roger Patrick

    2010-09-01

    Imported oil exacerabates our trade deficit and funds anti-American regimes. Nuclear Energy (NE) is a demonstrated technology with high efficiency. NE's two biggest political detriments are possible accidents and nuclear waste disposal. For NE policy, proliferation is the biggest obstacle. Nuclear waste can be reduced through reprocessing, where fuel rods are separated into various streams, some of which can be reused in reactors. Current process developed in the 1950s is dirty and expensive, U/Pu separation is the most critical. Fuel rods are sheared and dissolved in acid to extract fissile material in a centrifugal contactor. Plants have many contacts in series with other separations. We have taken a science and simulation-based approach to develop a modern reprocessing plant. Models of reprocessing plants are needed to support nuclear materials accountancy, nonproliferation, plant design, and plant scale-up.

  20. Mesoscale Fossil Diversity and Ecosystem Modeling in the Cenozoic

    NASA Astrophysics Data System (ADS)

    Brooks, B.; Cervato, C.

    2008-12-01

    Numerous experiments of extant ecosystems have tested aspects of modern niche theory as they relate to the development and maintenance of species richness in a geographic area. As such, species richness has often been observed to be a consequence of heterogeneous conditions within the ecosystem provided by environmental gradients, moderate levels of disturbance, and complex trophic interactions that give rise to niche partitioning. By contrast some studies of the fossil record have focused on identifying governing parameters for paleodiversity using instead simplified models of ecosystem interaction, which violate principles of niche theory. To examine ecosystem diversity within the most recent 60 Ma, we analyzed the depositional environment and lithologies of 17,984 globally distributed marine fossil assemblages, focusing on the relationship between diversity and ecosystem gradients. Our results indicate that although there is a myriad of factors that can provide for high fossil diversity within a geographic area, only a few ecosystem gradients are needed to explain the majority of that diversity. Our findings are consistent with modern niche theory and may extend the robustness of this concept significantly through time.

  1. The Next Version of the Canadian Operational GEM Regional Mesoscale Model

    NASA Astrophysics Data System (ADS)

    Mailhot, J.; Belair, S.; Tremblay, A.; Lefaivre, L.; Bilodeau, B.; Glazer, A.; Patoine, A.; Talbot, D.

    2003-04-01

    A new mesoscale version of the GEM regional model in operation in Canada for numerical weather prediction has been under development for some time. The main changes to the modeling system comprise an increased resolution both in the horizontal (15 km instead of 24 km) and the vertical (43 levels instead of 28) and improvements to almost every aspects of the physics package. These include an improved formulation of the boundary layer to represent clouds with an unified moist turbulence approach, the Kain-Fritsch deep convection scheme, and the Tremblay mixed-phase condensation scheme with explicit microphysics, together with revisions to the cloud radiative optical properties. The effect of low-level blocking due to subgrid-scale orography based on the Lott-Miller scheme has also been included. The performance of the new mesoscale modeling system has been compared against the current operational model for two 6-week cycles during winter and summer 2002. Based on the North American radiosondes, significant improvements are found in the bias and RMS errors of winds and temperatures. Objective precipitation scores also show significant improvements in winter for the bias and threat scores in almost all precipitation categories, while the scores are more similar during summer.

  2. Creep damage characterization using nonlinear ultrasonic guided wave method: A mesoscale model

    NASA Astrophysics Data System (ADS)

    Xiang, Yanxun; Deng, Mingxi; Xuan, Fu-Zhen

    2014-01-01

    The early deformations in materials such as creep, plasticity, and fatigue damages have been proved to have a close relationship with the nonlinear effect of ultrasonic waves propagating in them. In the present paper, a theoretical mesoscale model of an ultrasonic non-destructive method has been proposed to evaluate creep deformed states based on nonlinear guided waves. The model developed here considers the nonlinear generation of Lamb waves response from precipitates variation in the dislocation network, which can be applicable to all precipitate stages including coherent and semi-coherent precipitates in the metallic alloy undergoing creep degradation. To verify the proposed model, experiments of titanium alloy Ti60 plates were carried out with different creep strains. An "increase-decrease" change of the acoustic nonlinearity of guided wave versus the creep life fraction has been observed. Based on microscopic images analyses, the mesoscale model was then applied to these creep damaged Ti60 specimens, which revealed a good accordance with the measured results of the nonlinear guided waves. It is shown that the change of the nonlinear Lamb wave depends on the variations of the α2 precipitation volume fraction, the dislocation density, the growth of the creep-voids, and the increasing mismatch of the phase velocities during the creep deformation process. The results indicate that the effect of the precipitate-dislocation interactions on the nonlinear guided wave is likely the dominant mechanism responsible for the change of nonlinear guided wave propagation in the crept materials.

  3. Coupling NMM Mesoscale Weather Forecast Model with CALMET for Wind Energy Applications

    NASA Astrophysics Data System (ADS)

    Radonjic, Z.; Chambers, D.; Telenta, B.; Music, S.; Janjic, Z.

    2009-04-01

    A new and advanced mesoscale NMM (Nonhydrostatic Mesoscale Model)embeded in the framework - Forecast Refinement System Host (FReSH), was used in this application on the fine scale resolution (2 by 2 km). CALMET the U.S. EPA meteorological preprocessor (part of the CALMET/CALPUFF long range regulatory system) then applied on the resolutions of 100 by 100 m and 250 by 250 m. This study investigates the validation of FReSH3/CALMET against two data sets obtained from the meteorological towers at heights 58 and 62 m above the ground. Data set 1 was for a site at the elevation of 581 m above sea level (asl). Data set 2 was for a site at the elevation of 694 m - asl. The system is validated through a comparison of 10 minutes wind data measured and predicted by FReSH and the CALMET models. Case studies are used to investigate the capability of the models to predict the winds at the potential wind energy sites as well to demonstrate that the both models can be used to generate realistic forecasts for the wind energy sites often located at the hilly terrain.

  4. Meso-scale Modeling of Self-assembly of Polymer-Grafted Nanoparticles

    NASA Astrophysics Data System (ADS)

    Mancini, Derrick; Deshmukh, Sanket; Sankaranarayanan, Subramanian

    2015-03-01

    We develop meso-scale models to explore the self-assembly behavior of polymer-grafted nanoparticles. Specifically, we study nanoparticles with grafts of the thermo-sensitive polymer poly(N-isopropylacrylamide) (PNIPAM), which undergoes a coil-to-globule transition across the LCST at around 305 K. The atomic-scale mechanism of the coil-to-globule transition of polymers grafted nanoparticles and their interactions (agglomeration, assembly behavior) with other particles that are in its vicinity is poorly understood, yet knowledge about these interactions would enable designing novel self-assembled materials with well-defined structural and dynamical properties. Additionally, the effects of chemical nature, geometry, and morphology of the nanoparticle surface on the conformational transition of thermo-sensitive polymers is also unknown. We report on 1) development of all-atom models of polymer-grafted nanoparticles to conduct MD simulations at atomic-levels and 2) perform mesoscopic scaling of the conformational dynamics resulting from the atomistic simulations with the aid of coarse-grained or meso-scale models of PNIPAM and its composites. Coarse-grained simulations allow modeling of larger assemblies of polymer-grafted nanoparticles over longer time scales. This research used resources of the Center for Nanoscale Materials and the Argonne Leadership Computing Facility at Argonne National Laboratory, which is supported by the Office of Science of the U.S. Department of Energy under Contract DE-AC02-06CH11357.

  5. Meso-Scale Modeling to Characterize Moisture Absorption of 3D Woven Composite

    NASA Astrophysics Data System (ADS)

    Yuan, Yuan; Zhou, Chu-wei

    2016-03-01

    For polymer-matrix composites, moisture is expected to degrade their mechanical properties due to matrix plasticization and moisture introduced micro-scale defects. In this study, the moisture absorptions of bulk epoxy, unidirectional composite (UD) and 3D woven composite (3D WC) were tested. Two-stage features have been observed for all these three materials. Moisture properties for UD and 3D WC were found not in simple direct proportion to their matrix volume fractions. The moisture approach of UD was modeled including the effect of fiber/matrix interphase which promotes the moisture uptake. Then, meso-scale FE model for 3D WC was established to characterize the inhomogeneous moisture diffusion. The moisture properties of resin-rich region and fiber bundle in 3D WC were determined from water uptake experiments of bulk epoxy and UD, respectively. Through homogenizing moisture properties of surface and interior weave structures, a simplified theoretical sandwich moisture diffusion approach was established. The moisture weight gains of 3D WC predicted by both meso-scale FE model and simplified sandwich approach were well agreed with the experimental data.

  6. Meso-Scale Modeling to Characterize Moisture Absorption of 3D Woven Composite

    NASA Astrophysics Data System (ADS)

    Yuan, Yuan; Zhou, Chu-wei

    2016-08-01

    For polymer-matrix composites, moisture is expected to degrade their mechanical properties due to matrix plasticization and moisture introduced micro-scale defects. In this study, the moisture absorptions of bulk epoxy, unidirectional composite (UD) and 3D woven composite (3D WC) were tested. Two-stage features have been observed for all these three materials. Moisture properties for UD and 3D WC were found not in simple direct proportion to their matrix volume fractions. The moisture approach of UD was modeled including the effect of fiber/matrix interphase which promotes the moisture uptake. Then, meso-scale FE model for 3D WC was established to characterize the inhomogeneous moisture diffusion. The moisture properties of resin-rich region and fiber bundle in 3D WC were determined from water uptake experiments of bulk epoxy and UD, respectively. Through homogenizing moisture properties of surface and interior weave structures, a simplified theoretical sandwich moisture diffusion approach was established. The moisture weight gains of 3D WC predicted by both meso-scale FE model and simplified sandwich approach were well agreed with the experimental data.

  7. Leatherback nests increasing significantly in Florida, USA; trends assessed over 30 years using multilevel modeling.

    PubMed

    Stewart, Kelly; Sims, Michelle; Meylan, Anne; Witherington, Blair; Brost, Beth; Crowder, Larry B

    2011-01-01

    Understanding population status for endangered species is critical to developing and evaluating recovery plans mandated by the Endangered Species Act. For sea turtles, changes in abundance are difficult to detect because most life stages occur in the water. Currently, nest counts are the most reliable way of assessing trends. We determined the rate of growth for leatherback turtle (Dermochelys coriacea) nest numbers in Florida (USA) using a multilevel Poisson regression. We modeled nest counts from 68 beaches over 30 years and, using beach-level covariates (including latitude), we allowed for partial pooling of information between neighboring beaches. This modeling approach is ideal for nest count data because it recognizes the hierarchical structure of the data while incorporating variables related to survey effort. Nesting has increased at all 68 beaches in Florida, with trends ranging from 3.1% to 16.3% per year. Overall, across the state, the number of nests has been increasing by 10.2% per year since 1979. Despite being a small population (probably < 1000 individuals), this nesting population may help achieve objectives in the federal recovery plan. This exponential growth rate mirrors trends observed for other Atlantic populations and may be driven partially by improved protection of nesting beaches. However, nesting is increasing even where beach protection has not been enhanced. Climate variability and associated marine food web dynamics, which could enhance productivity and reduce predators, may be driving this trend. PMID:21516903

  8. Propagation of impact-induced shock waves in porous sandstone using mesoscale modeling

    NASA Astrophysics Data System (ADS)

    GÜLdemeister, Nicole; WÜNnemann, Kai; Durr, Nathanael; Hiermaier, Stefan

    2013-01-01

    Abstract-Generation and propagation of shock waves by meteorite impact is significantly affected by material properties such as porosity, water content, and strength. The objective of this work was to quantify processes related to the shock-induced compaction of pore space by numerical <span class="hlt">modeling</span>, and compare the results with data obtained in the framework of the Multidisciplinary Experimental and <span class="hlt">Modeling</span> Impact Research Network (MEMIN) impact experiments. We use <span class="hlt">mesoscale</span> <span class="hlt">models</span> resolving the collapse of individual pores to validate macroscopic (homogenized) approaches describing the bulk behavior of porous and water-saturated materials in large-scale <span class="hlt">models</span> of crater formation, and to quantify localized shock amplification as a result of pore space crushing. We carried out a suite of numerical <span class="hlt">models</span> of planar shock wave propagation through a well-defined area (the "sample") of porous and/or water-saturated material. The porous sample is either represented by a homogeneous unit where porosity is treated as a state variable (macroscale <span class="hlt">model</span>) and water content by an equation of state for mixed material (ANEOS) or by a defined number of individually resolved pores (<span class="hlt">mesoscale</span> <span class="hlt">model</span>). We varied porosity and water content and measured thermodynamic parameters such as shock wave velocity and particle velocity on meso- and macroscales in separate simulations. The <span class="hlt">mesoscale</span> <span class="hlt">models</span> provide additional data on the heterogeneous distribution of peak shock pressures as a consequence of the complex superposition of reflecting rarefaction waves and shock waves originating from the crushing of pores. We quantify the bulk effect of porosity, the reduction in shock pressure, in terms of Hugoniot data as a function of porosity, water content, and strength of a quartzite matrix. We find a good agreement between meso-, macroscale <span class="hlt">models</span> and Hugoniot data from shock experiments. We also propose a combination of a porosity compaction <span class="hlt">model</span> (ɛ-α <span class="hlt">model</span>) that was</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://pubs.er.usgs.gov/publication/70028853','USGSPUBS'); return false;" href="http://pubs.er.usgs.gov/publication/70028853"><span id="translatedtitle">Determinants of wood thrush <span class="hlt">nest</span> success: A multi-scale, <span class="hlt">model</span> selection approach</span></a></p> <p><a target="_blank" href="http://pubs.er.usgs.gov/pubs/index.jsp?view=adv">USGS Publications Warehouse</a></p> <p>Driscoll, M.J.L.; Donovan, T.; Mickey, R.; Howard, A.; Fleming, K.K.</p> <p>2005-01-01</p> <p>We collected data on 212 wood thrush (Hylocichla mustelina) <span class="hlt">nests</span> in central New York from 1998 to 2000 to determine the factors that most strongly influence <span class="hlt">nest</span> success. We used an information-theoretic approach to assess and rank 9 <span class="hlt">models</span> that examined the relationship between <span class="hlt">nest</span> success (i.e., the probability that a <span class="hlt">nest</span> would successfully fledge at least 1 wood thrush offspring) and habitat conditions at different spatial scales. We found that 4 variables were significant predictors of <span class="hlt">nesting</span> success for wood thrushes: (1) total core habitat within 5 km of a study site, (2) distance to forest-field edge, (3) total forest cover within 5 km of the study site, and (4) density and variation in diameter of trees and shrubs surrounding the <span class="hlt">nest</span>. The coefficients of these predictors were all positive. Of the 9 <span class="hlt">models</span> evaluated, amount of core habitat in the 5-km landscape was the best-fit <span class="hlt">model</span>, but the vegetation structure <span class="hlt">model</span> (i.e., the density of trees and stems surrounding a <span class="hlt">nest</span>) was also supported by the data. Based on AIC weights, enhancement of core area is likely to be a more effective management option than any other habitat-management options explored in this study. Bootstrap analysis generally confirmed these results; core and vegetation structure <span class="hlt">models</span> were ranked 1, 2, or 3 in over 50% of 1,000 bootstrap trials. However, bootstrap results did not point to a decisive <span class="hlt">model</span>, which suggests that multiple habitat factors are influencing wood thrush <span class="hlt">nesting</span> success. Due to <span class="hlt">model</span> uncertainty, we used a <span class="hlt">model</span> averaging approach to predict the success or failure of each <span class="hlt">nest</span> in our dataset. This averaged <span class="hlt">model</span> was able to correctly predict 61.1% of <span class="hlt">nest</span> outcomes.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015JGRD..120.3920S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015JGRD..120.3920S"><span id="translatedtitle">Impact of new aircraft observations Mode-S MRAR in a <span class="hlt">mesoscale</span> NWP <span class="hlt">model</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Strajnar, B.; Žagar, N.; Berre, L.</p> <p>2015-05-01</p> <p>The impact of recently available high-resolution Mode-S Meteorological Routine Air Report (MRAR) wind and temperature observations is evaluated in the <span class="hlt">mesoscale</span> numerical weather prediction (NWP) <span class="hlt">model</span> Aire Limitée Adaptation dynamique Développement InterNational (ALADIN). Data available from the airspace communicating with the Ljubljana Airport in Slovenia are assimilated by using the three-dimensional variational assimilation procedure on top of all other observations assimilated operationally. A data selection method based on aircraft type was shown to be important for the first application of the new observations in ALADIN. The evaluation of Mode-S MRAR impact included both winter and summer periods. In both seasons a clear improvement of wind and temperature forecasts was found for in the short forecast range, 1-3 h. The impact in the 24 h forecast range depends on season, with a consistent positive improvement of the boundary layer temperature forecasts obtained for the stable anticyclonic winter situations. In summer, the impact was mixed and it was found to be sensitive to the multivariate aspects of the moisture analysis. Overall presented results suggest that the new aircraft-derived observations Mode-S MRAR have a significant potential for <span class="hlt">mesoscale</span> NWP and improved data assimilation <span class="hlt">modeling</span>.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2015EGUGA..17.1154P&link_type=ABSTRACT','NASAADS'); return false;" href="http://adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2015EGUGA..17.1154P&link_type=ABSTRACT"><span id="translatedtitle">The impact of vertical resolution in <span class="hlt">mesoscale</span> <span class="hlt">model</span> AROME forecasting of radiation fog</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Philip, Alexandre; Bergot, Thierry; Bouteloup, Yves; Bouyssel, François</p> <p>2015-04-01</p> <p>Airports short-term forecasting of fog has a security and economic impact. Numerical simulations have been performed with the <span class="hlt">mesoscale</span> <span class="hlt">model</span> AROME (Application of Research to Operations at <span class="hlt">Mesoscale</span>) (Seity et al. 2011). Three vertical resolutions (60, 90 and 156 levels) are used to show the impact of radiation fog on numerical forecasting. Observations at Roissy Charles De Gaulle airport are compared to simulations. Significant differences in the onset, evolution and dissipation of fog were found. The high resolution simulation is in better agreement with observations than a coarser one. The surface boundary layer and incoming long-wave radiations are better represented. A more realistic behaviour of liquid water content evolution allows a better anticipation of low visibility procedures (ceiling < 60m and/or visibility < 600m). The case study of radiation fog shows that it is necessary to have a well defined vertical grid to better represent local phenomena. A statistical study over 6 months (October 2011 - March 2012 ) using different configurations was carried out. Statistically, results were the same as in the case study of radiation fog. Seity Y., P. Brousseau, S. Malardel, G. Hello, P. Bénard, F. Bouttier, C. Lac, V. Masson, 2011: The AROME-France convective scale operational <span class="hlt">model</span>. Mon.Wea.Rev., 139, 976-991.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2013AGUFMGC41C1015W','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2013AGUFMGC41C1015W"><span id="translatedtitle">Projected changes of extreme precipitation over Contiguous United States with <span class="hlt">Nested</span> regional climate <span class="hlt">model</span> (NRCM)</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Wang, J.</p> <p>2013-12-01</p> <p>Extreme weather events have already significantly influenced North America. During 2005-2011, the extreme events have increased by 250 %, from four or fewer events occurring in 2005, while 14 events occurring in 2011 (www.ncdc.noaa.gov/billions/). In addition, extreme rainfall amounts, frequency, and intensity were all expected to increase under greenhouse warming scenarios (Wehner 2005; Kharin et al. 2007; Tebaldi et al. 2006). Global <span class="hlt">models</span> are powerful tools to investigate the climate and climate change on large scales. However, such <span class="hlt">models</span> do not represent local terrain and <span class="hlt">mesoscale</span> weather systems well owing to their coarse horizontal resolution (150-300 km). To capture the fine-scale features of extreme weather events, regional climate <span class="hlt">models</span> (RCMs) with a more realistic representation of the complex terrain and heterogeneous land surfaces are needed (Mass et al. 2002). This study uses the <span class="hlt">Nested</span> Regional Climate <span class="hlt">model</span> (NRCM) to perform regional scale climate simulations on a 12-km × 12-km high resolution scale over North America (including Alaska; with 600 × 515 grid cells at longitude and latitude), known as CORDEX_North America, instead of small regions as studied previously (eg., Dominguez et al. 2012; Gao et al. 2012). The performance and the biases of the NRCM extreme precipitation calculations (2000-2010) have been evaluated with PRISM precipitation (Daly et al. 1997) by Wang and Kotamarthi (2013): the NRCM replicated very well the monthly amount of extreme precipitation with less than 3% overestimation over East CONUS, and the frequency of extremes over West CONUS and upper Mississippi River Basin. The Representative Concentration Pathway (RCP) 8.5 and RCP 4.5 from the new Community Earth System <span class="hlt">Model</span> version 1.0 (CESM v1.0) are dynamically downscaled to predict the extreme rainfall events at the end-of-century (2085-2095) and to explore the uncertainties of future extreme precipitation induced by different scenarios over distinct regions. We have</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/1999MAP....71..229G','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/1999MAP....71..229G"><span id="translatedtitle">Effects of a Total Solar Eclipse on the <span class="hlt">Mesoscale</span> Atmospheric Circulation over Europe - A <span class="hlt">Model</span> Experiment</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Gross, P.; Hense, A.</p> <p></p> <p>On August the 11th, 1999 Central Europe saw a spectacular astronomical event, a total solar eclipse. We present a <span class="hlt">model</span> study concerning the meteorological effects of this eclipse in central Europe using the state-of-the-art limited area forecast <span class="hlt">model</span> Deutschland-<span class="hlt">Modell</span> DM from the German Weather Service DWD. Under typical summer radiation conditions very strong anomalies in the surface energy flux and temperature in screen height are simulated. The main temperature signal in the lower troposphere is delayed by about one hour with respect to the surface. Furthermore it is connected with a well defined dynamical signal which is reminiscent to a large scale land - sea circulation. The event could be used as a test case for <span class="hlt">mesoscale</span> atmospheric <span class="hlt">models</span>.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015ACPD...1527539R','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015ACPD...1527539R"><span id="translatedtitle">Controlled meteorological (CMET) balloon profiling of the Arctic atmospheric boundary layer around Spitsbergen compared to a <span class="hlt">mesoscale</span> <span class="hlt">model</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Roberts, T. J.; Dütsch, M.; Hole, L. R.; Voss, P. B.</p> <p>2015-10-01</p> <p>Observations from CMET (Controlled Meteorological) balloons are analyzed in combination with <span class="hlt">mesoscale</span> <span class="hlt">model</span> simulations to provide insights into tropospheric meteorological conditions (temperature, humidity, wind-speed) around Svalbard, European High Arctic. Five Controlled Meteorological (CMET) balloons were launched from Ny-Ålesund in Svalbard over 5-12 May 2011, and measured vertical atmospheric profiles above Spitsbergen Island and over coastal areas to both the east and west. One notable CMET flight achieved a suite of 18 continuous soundings that probed the Arctic marine boundary layer over a period of more than 10 h. The CMET profiles are compared to simulations using the Weather Research and Forecasting (WRF) <span class="hlt">model</span> using <span class="hlt">nested</span> grids and three different boundary layer schemes. Variability between the three <span class="hlt">model</span> schemes was typically smaller than the discrepancies between the <span class="hlt">model</span> runs and the observations. Over Spitsbergen, the CMET flights identified temperature inversions and low-level jets (LLJ) that were not captured by the <span class="hlt">model</span>. Nevertheless, the <span class="hlt">model</span> largely reproduced time-series obtained from the Ny-Ålesund meteorological station, with exception of surface winds during the LLJ. Over sea-ice east of Svalbard the <span class="hlt">model</span> underestimated potential temperature and overestimated wind-speed compared to the CMET observations. This is most likely due to the full sea-ice coverage assumed by the <span class="hlt">model</span>, and consequent underestimation of ocean-atmosphere exchange in the presence of leads or fractional coverage. The suite of continuous CMET soundings over a sea-ice free region to the northwest of Svalbard are analysed spatially and temporally, and compared to the <span class="hlt">model</span>. The observed along-flight daytime increase in relative humidity is interpreted in terms of the diurnal cycle, and in the context of marine and terrestrial air-mass influences. Analysis of the balloon trajectory during the CMET soundings identifies strong wind-shear, with a low-level channeled</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2014AGUFM.A43A3240T&link_type=ABSTRACT','NASAADS'); return false;" href="http://adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2014AGUFM.A43A3240T&link_type=ABSTRACT"><span id="translatedtitle">Characterization of <span class="hlt">Mesoscale</span> Variability in WRF - a Coastal Low-Level Jet Case Study</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Tay, K.; Lundquist, J. K.; Skote, M.; Koh, T. Y.</p> <p>2014-12-01</p> <p><span class="hlt">Mesoscale</span> weather <span class="hlt">models</span> have increasingly been featured in wind resource assessment development. The incorporation of real meteorological conditions into such assessments allow a more realistic, physical determination of the wind loads that will be experienced within a wind farm site. Large-Eddy Simulation (LES) confers the advantage of representing finer scale turbulence, such as wake effects. However, <span class="hlt">nesting</span> LES within real <span class="hlt">mesoscale</span> simulations is still in the nascent stage of development. One of the difficulties lies in providing accurate <span class="hlt">mesoscale</span> forcing boundaries for the LES domain. This study aims to characterize the <span class="hlt">mesoscale</span> variability in WRF to lay the groundwork for future <span class="hlt">mesoscale</span>-LES <span class="hlt">nested</span> simulations. A low-level jet (LLJ) event that was observed during the CBLAST-Low 2001 campaign (07 Aug to 09 Aug) provides a robust case study to test the capabilities of and characterize the <span class="hlt">mesoscale</span> variabilities in WRF. The dynamical interaction of a frontal passage with a stable boundary layer over a coastal region makes this an interesting and challenging case for real <span class="hlt">mesoscale</span> simulation and future LES <span class="hlt">nested</span> simulations. Sensitivities to vertical resolution, PBL schemes and initial forcing datasets were tested. This presentation will describe and explain the factors that influence the simulation of this frontal passage and the resulting LLJ. The initial forcing datasets have a major influence on spatial and temporal characteristics, as seen in Figure 1, introducing larger differences than the PBL schemes do. Furthermore, the <span class="hlt">mesoscale</span> simulation also showed a strong dependence on the vertical resolution: increasing the vertical resolution within the atmospheric boundary layer resulted in a more accurate vertical profile for wind speed. Lastly, the simulations did show a dependency on the PBL scheme selected however, the variability between PBL schemes were not large, especially compared to the variability introduced by the boundary and initial</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/20010037609','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20010037609"><span id="translatedtitle">A Study of Heavy Precipitation Events in Taiwan During 10-13 August, 1994. Part 2; <span class="hlt">Mesoscale</span> <span class="hlt">Model</span> Simulations</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Tao, Wei Kuo; Chen, C.-S.; Jia, Y.; Baker, D.; Lang, S.; Wetzel, P.; Lau, W. K.-M.</p> <p>2001-01-01</p> <p>Several heavy precipitation episodes occurred over Taiwan from August 10 to 13, 1994. Precipitation patterns and characteristics are quite different between the precipitation events that occurred from August 10 and I I and from August 12 and 13. In Part I (Chen et al. 2001), the environmental situation and precipitation characteristics are analyzed using the EC/TOGA data, ground-based radar data, surface rainfall patterns, surface wind data, and upper air soundings. In this study (Part II), the Penn State/NCAR <span class="hlt">Mesoscale</span> <span class="hlt">Model</span> (MM5) is used to study the precipitation characteristics of these heavy precipitation events. Various physical processes (schemes) developed at NASA Goddard Space Flight Center (i.e., cloud microphysics scheme, radiative transfer <span class="hlt">model</span>, and land-soil-vegetation surface <span class="hlt">model</span>) have recently implemented into the MM5. These physical packages are described in the paper, Two way interactive <span class="hlt">nested</span> grids are used with horizontal resolutions of 45, 15 and 5 km. The <span class="hlt">model</span> results indicated that Cloud physics, land surface and radiation processes generally do not change the location (horizontal distribution) of heavy precipitation. The Goddard 3-class ice scheme produced more rainfall than the 2-class scheme. The Goddard multi-broad-band radiative transfer <span class="hlt">model</span> reduced precipitation compared to a one-broad band (emissivity) radiation <span class="hlt">model</span>. The Goddard land-soil-vegetation surface <span class="hlt">model</span> also reduce the rainfall compared to a simple surface <span class="hlt">model</span> in which the surface temperature is computed from a Surface energy budget following the "force-re store" method. However, <span class="hlt">model</span> runs including all Goddard physical processes enhanced precipitation significantly for both cases. The results from these runs are in better agreement with observations. Despite improved simulations using different physical schemes, there are still some deficiencies in the <span class="hlt">model</span> simulations. Some potential problems are discussed. Sensitivity tests (removing either terrain or radiative</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/23584035','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/23584035"><span id="translatedtitle">Issues related to aircraft take-off plumes in a <span class="hlt">mesoscale</span> photochemical <span class="hlt">model</span>.</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Bossioli, Elissavet; Tombrou, Maria; Helmis, Costas; Kurtenbach, Ralf; Wiesen, Peter; Schäfer, Klaus; Dandou, Aggeliki; Varotsos, Kostas V</p> <p>2013-07-01</p> <p>The physical and chemical characteristics of aircraft plumes at the take-off phase are simulated with the <span class="hlt">mesoscale</span> CAMx <span class="hlt">model</span> using the individual plume segment approach, in a highly resolved domain, covering the Athens International Airport. Emission indices during take-off measured at the Athens International Airport are incorporated. <span class="hlt">Model</span> predictions are compared with in situ point and path-averaged observations (NO, NO₂) downwind of the runway at the ground. The influence of <span class="hlt">modeling</span> process, dispersion properties and background air composition on the chemical evolution of the aircraft plumes is examined. It is proven that the mixing properties mainly determine the plume dispersion. The initial plume properties become significant for the selection of the appropriate vertical resolution. Besides these factors, the background NOx and O₃ concentration levels control NOx distribution and their conversion to nitrogen reservoir species. PMID:23584035</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015GMD.....8.2645N','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015GMD.....8.2645N"><span id="translatedtitle">High-resolution numerical <span class="hlt">modeling</span> of <span class="hlt">mesoscale</span> island wakes and sensitivity to static topographic relief data</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Nunalee, C. G.; Horváth, Á.; Basu, S.</p> <p>2015-08-01</p> <p>Recent decades have witnessed a drastic increase in the fidelity of numerical weather prediction (NWP) <span class="hlt">modeling</span>. Currently, both research-grade and operational NWP <span class="hlt">models</span> regularly perform simulations with horizontal grid spacings as fine as 1 km. This migration towards higher resolution potentially improves NWP <span class="hlt">model</span> solutions by increasing the resolvability of <span class="hlt">mesoscale</span> processes and reducing dependency on empirical physics parameterizations. However, at the same time, the accuracy of high-resolution simulations, particularly in the atmospheric boundary layer (ABL), is also sensitive to orographic forcing which can have significant variability on the same spatial scale as, or smaller than, NWP <span class="hlt">model</span> grids. Despite this sensitivity, many high-resolution atmospheric simulations do not consider uncertainty with respect to selection of static terrain height data set. In this paper, we use the Weather Research and Forecasting (WRF) <span class="hlt">model</span> to simulate realistic cases of lower tropospheric flow over and downstream of mountainous islands using the default global 30 s United States Geographic Survey terrain height data set (GTOPO30), the Shuttle Radar Topography Mission (SRTM), and the Global Multi-resolution Terrain Elevation Data set (GMTED2010) terrain height data sets. While the differences between the SRTM-based and GMTED2010-based simulations are extremely small, the GTOPO30-based simulations differ significantly. Our results demonstrate cases where the differences between the source terrain data sets are significant enough to produce entirely different orographic wake mechanics, such as vortex shedding vs. no vortex shedding. These results are also compared to MODIS visible satellite imagery and ASCAT near-surface wind retrievals. Collectively, these results highlight the importance of utilizing accurate static orographic boundary conditions when running high-resolution <span class="hlt">mesoscale</span> <span class="hlt">models</span>.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2007sos..symp...87M','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2007sos..symp...87M"><span id="translatedtitle">Optical Turbulence simulations with <span class="hlt">meso-scale</span> <span class="hlt">models</span>. Towards a new ground-based astronomy era</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Masciadri, Elena</p> <p></p> <p>The optical turbulence characterization made with atmospherical <span class="hlt">meso-scale</span> <span class="hlt">models</span> for astronomical applications is a relatively recent approach (first studies have been published in the ninety). Simulations retrieved from such <span class="hlt">models</span> can be fundamental for the optimization of the AO techniques and characterization and selection of astronomical sites. In most cases, simulations and measurements provide complementary information on turbulence features. The potentialities related to the numerical approach and the most fundamental scientific challenges related to <span class="hlt">meso-scale</span> atmospheric <span class="hlt">models</span> rely upon the possibility (1) to describe a 3D map of the CN2 in a region around a telescope, (2) to forecast the optical turbulence i.e. to know with some hours in advance the state of the turbulence conditions above an astronomical site and (3) to perform a climatology of the optical turbulence extended over decades. The forecast of the optical turbulence is a fundamental requirement for the optimization of the management of the scientific programs to be carried out at ground-based telescopes foci. Ground-based astronomy will remain competitive with respect to the space-based one only if telescopes management will be performed taking advantage of the best turbulence conditions. The future of new ground- based telescopes generation relies therefore upon the success of these studies. No other tool of investigation with comparable potentialities can be figured out at present to achieve these 3 scientific goals. However, these highly challenging goals are associated to an intrinsic difficulty in parameterizing a physical process such as turbulence evolving at spatial and temporal scales smaller than what usually resolved by a <span class="hlt">meso-scale</span> <span class="hlt">model</span>. In this talk I will summarize the main results and progress achieved so far in this field since the ninety and I will present the most important scientific goals for the near and far future research. I will conclude with a brief presentation</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/19930010901','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19930010901"><span id="translatedtitle">Nonhydrostatic effects in numerical <span class="hlt">modeling</span> of <span class="hlt">mesoscale</span> convective systems and baroclinic waves</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Cohen, Charles</p> <p>1993-01-01</p> <p>The present investigation is concerned with the role of convection upon <span class="hlt">mesoscale</span> <span class="hlt">modeling</span> results, particularly when the grid resolution becomes small enough that there is not a clear scale separation between the explicitly resolved circulations and the parameterized clouds. In those situations, the vertical accelerations in explicitly resolved circulations become strong enough that the hydrostatic assumption may no longer be valid. These concerns arise from interests in improving <span class="hlt">mesoscale</span> <span class="hlt">modeling</span> per se and in improving the subgrid-scale parameterizations in global <span class="hlt">models</span>. The hydrostatic and the nonhydrostatic options of the Colorado State University Regional Atmospheric <span class="hlt">Modeling</span> System were used to simulate dry gravity currents in two dimensions, using several different horizontal grid sizes. With horizontal grid intervals of 10 km or less, nonhydrostatic simulations produce wider and colder heads and weaker but wider forced updrafts than do the hydrostatic simulations. Comparing the hydrostatic and nonhydrostatic <span class="hlt">models</span> show that the difference between the vertical mass fluxes is much less than the difference between the vertical velocities. When the grid is fine enough to resolve the head of the gravity current, horizontal convergence at the gust front extends upwards almost to the head of the cold air. Vertical mass flux in the forced updraft at the front varies with horizontal grid size mainly as a function of the height of the simulated head. For coarser grids, which do not resolve the head, vertical mass flux at all heights decreases with increasing horizontal grid size. A comparison on nonhydrostatic simulations with horizontal grid intervals of 1 km and 2 km illustrates how decreasing the grid size does not necessarily increase the intensity of the resolved circulation. The smaller grid enables the simulated gravity current to entrain a bubble of warm air behind the head, which results in a weaker circulation with a shorter head and weaker updraft.</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_9");'>9</a></li> <li><a href="#" onclick='return showDiv("page_10");'>10</a></li> <li class="active"><span>11</span></li> <li><a href="#" onclick='return showDiv("page_12");'>12</a></li> <li><a href="#" onclick='return showDiv("page_13");'>13</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_11 --> <div id="page_12" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_10");'>10</a></li> <li><a href="#" onclick='return showDiv("page_11");'>11</a></li> <li class="active"><span>12</span></li> <li><a href="#" onclick='return showDiv("page_13");'>13</a></li> <li><a href="#" onclick='return showDiv("page_14");'>14</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="221"> <li> <p><a target="_blank" onclick="trackOutboundLink('http://ntrs.nasa.gov/search.jsp?R=19880060530&hterms=pea&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D80%26Ntt%3Dpea','NASA-TRS'); return false;" href="http://ntrs.nasa.gov/search.jsp?R=19880060530&hterms=pea&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D80%26Ntt%3Dpea"><span id="translatedtitle"><span class="hlt">Mesoscale</span> spiral vortex embedded within a Lake Michigan snow squall band - High resolution satellite observations and numerical <span class="hlt">model</span> simulations</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Lyons, Walter A.; Keen, Cecil S.; Hjelmfelt, Mark; Pease, Steven R.</p> <p>1988-01-01</p> <p>It is known that Great Lakes snow squall convection occurs in a variety of different modes depending on various factors such as air-water temperature contrast, boundary-layer wind shear, and geostrophic wind direction. An exceptional and often neglected source of data for <span class="hlt">mesoscale</span> cloud studies is the ultrahigh resolution multispectral data produced by Landsat satellites. On October 19, 1972, a clearly defined spiral vortex was noted in a Landsat-1 image near the southern end of Lake Michigan during an exceptionally early cold air outbreak over a still very warm lake. In a numerical simulation using a three-dimensional Eulerian hydrostatic primitive equation <span class="hlt">mesoscale</span> <span class="hlt">model</span> with an initially uniform wind field, a definite analog to the observed vortex was generated. This suggests that intense surface heating can be a principal cause in the development of a low-level <span class="hlt">mesoscale</span> vortex.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2016Geomo.256...68V&link_type=ABSTRACT','NASAADS'); return false;" href="http://adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2016Geomo.256...68V&link_type=ABSTRACT"><span id="translatedtitle">Simulating <span class="hlt">mesoscale</span> coastal evolution for decadal coastal management: A new framework integrating multiple, complementary <span class="hlt">modelling</span> approaches</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>van Maanen, Barend; Nicholls, Robert J.; French, Jon R.; Barkwith, Andrew; Bonaldo, Davide; Burningham, Helene; Brad Murray, A.; Payo, Andres; Sutherland, James; Thornhill, Gillian; Townend, Ian H.; van der Wegen, Mick; Walkden, Mike J. A.</p> <p>2016-03-01</p> <p>Coastal and shoreline management increasingly needs to consider morphological change occurring at decadal to centennial timescales, especially that related to climate change and sea-level rise. This requires the development of morphological <span class="hlt">models</span> operating at a <span class="hlt">mesoscale</span>, defined by time and length scales of the order 101 to 102 years and 101 to 102 km. So-called 'reduced complexity' <span class="hlt">models</span> that represent critical processes at scales not much smaller than the primary scale of interest, and are regulated by capturing the critical feedbacks that govern landform behaviour, are proving effective as a means of exploring emergent coastal behaviour at a landscape scale. Such <span class="hlt">models</span> tend to be computationally efficient and are thus easily applied within a probabilistic framework. At the same time, reductionist <span class="hlt">models</span>, built upon a more detailed description of hydrodynamic and sediment transport processes, are capable of application at increasingly broad spatial and temporal scales. More qualitative <span class="hlt">modelling</span> approaches are also emerging that can guide the development and deployment of quantitative <span class="hlt">models</span>, and these can be supplemented by varied data-driven <span class="hlt">modelling</span> approaches that can achieve new explanatory insights from observational datasets. Such disparate approaches have hitherto been pursued largely in isolation by mutually exclusive <span class="hlt">modelling</span> communities. Brought together, they have the potential to facilitate a step change in our ability to simulate the evolution of coastal morphology at scales that are most relevant to managing erosion and flood risk. Here, we advocate and outline a new integrated <span class="hlt">modelling</span> framework that deploys coupled <span class="hlt">mesoscale</span> reduced complexity <span class="hlt">models</span>, reductionist coastal area <span class="hlt">models</span>, data-driven approaches, and qualitative conceptual <span class="hlt">models</span>. Integration of these heterogeneous approaches gives rise to <span class="hlt">model</span> compositions that can potentially resolve decadal- to centennial-scale behaviour of diverse coupled open coast, estuary and inner</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/biblio/1222552','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/biblio/1222552"><span id="translatedtitle">A creep-damage <span class="hlt">model</span> for <span class="hlt">mesoscale</span> simulations of concrete expansion-degradation phenomena</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Giorla, Alain B; Le Pape, Yann</p> <p>2015-01-01</p> <p>Long-term performance of aging concrete in nuclear power plants (NPPs) requires a careful examination of the physical phenomena taking place in the material. Concrete under high neutron irradiation is subjected to large irreversible deformations as well as mechanical damage, caused by a swelling of the aggregates. However, these results, generally obtained in accelerated conditions in test reactors, cannot be directly applied to NPP irradiated structures, i.e., the biological shield, operating conditions due to difference in time scale and environmental conditions (temperature, humidity). <span class="hlt">Mesoscale</span> numerical simulations are performed to separate the underlying mechanisms and their interactions. The cement paste creep-damage <span class="hlt">model</span> accounts for the effect of the loading rate on the apparent damage properties of the material and uses an event-based approach to capture the competition between creep and damage. The <span class="hlt">model</span> is applied to the simulation of irradiation experiments from the literature and shows a good agreement with the experimental data.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://ntrs.nasa.gov/search.jsp?R=19950052180&hterms=katabatic+winds&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D10%26Ntt%3Dkatabatic%2Bwinds','NASA-TRS'); return false;" href="http://ntrs.nasa.gov/search.jsp?R=19950052180&hterms=katabatic+winds&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D10%26Ntt%3Dkatabatic%2Bwinds"><span id="translatedtitle">A <span class="hlt">mesoscale</span> <span class="hlt">modeling</span> study of the atmospheric circulation of high southern latitudes</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Hines, K. M.; Bromwich, David H.; Parish, T. R.</p> <p>1995-01-01</p> <p>The meteorology of high southern latitudes during winter is simulated using a cloud-free version of The Pennsylvania State University-National Center for Atmospheric Research <span class="hlt">Mesoscale</span> <span class="hlt">Model</span> version 4 (MM4) with a 100-km horizontal resolution. Comparisons between idealized simulations of Antarctic with MM4 and with the <span class="hlt">mesoscale</span> <span class="hlt">model</span> of Parish and Waight reveal that both <span class="hlt">models</span> produce similarly realistic velocity fields in the boundary layer. The latter <span class="hlt">model</span> tends to produce slightly faster drainage winds over East Antarctica. The intensity of the katabatic winds produced by MM4 is sensitive to parameterizations of boundary layer fluxes. Two simulations performed with MM4 using analyses from the European Center for Medium-Range Weather Forecasts (ECMWF) for June 1988 as initial and boundary conditions. A simulation of the period from 000 UTC 2 June to 0000 UTC 8 June produces realistic synoptic phenomena including ridge development over East Antarctica, frontogenesis over the Amundsen Sea, and a katabatic surge over the Ross Ice Shelf. The simulated time-averaged fields for June 1988, particularly that of a 500-hPa height, are in good agreement with time-averaged fields analyzed by the ECMWF. The results of the simulations provide detailed features of the Antarctic winter boundary layer along the steeply sloping terrain. Highest boundary layer wind speeds averaged over the month-long simulation are approximately 20 m/s. The lack of latent heating in the simulations apparently results in some bias in the results. In particular, the cloud-free version of MM4 underpredicts the intensity of lows in the sea level pressure field.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://dceg.cancer.gov/tools/analysis/nested-cohort','NCI'); return false;" href="http://dceg.cancer.gov/tools/analysis/nested-cohort"><span id="translatedtitle"><span class="hlt">Nested</span> Cohort</span></a></p> <p><a target="_blank" href="http://www.cancer.gov">Cancer.gov</a></p> <p></p> <p></p> <p><span class="hlt">Nested</span>Cohort is an R software package for fitting Kaplan-Meier and Cox <span class="hlt">Models</span> to estimate standardized survival and attributable risks for studies where covariates of interest are observed on only a sample of the cohort.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/biblio/22230857','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/biblio/22230857"><span id="translatedtitle">Hybrid <span class="hlt">nested</span> sampling algorithm for Bayesian <span class="hlt">model</span> selection applied to inverse subsurface flow problems</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Elsheikh, Ahmed H.; Wheeler, Mary F.; Hoteit, Ibrahim</p> <p>2014-02-01</p> <p>A Hybrid <span class="hlt">Nested</span> Sampling (HNS) algorithm is proposed for efficient Bayesian <span class="hlt">model</span> calibration and prior <span class="hlt">model</span> selection. The proposed algorithm combines, <span class="hlt">Nested</span> Sampling (NS) algorithm, Hybrid Monte Carlo (HMC) sampling and gradient estimation using Stochastic Ensemble Method (SEM). NS is an efficient sampling algorithm that can be used for Bayesian calibration and estimating the Bayesian evidence for prior <span class="hlt">model</span> selection. <span class="hlt">Nested</span> sampling has the advantage of computational feasibility. Within the <span class="hlt">nested</span> sampling algorithm, a constrained sampling step is performed. For this step, we utilize HMC to reduce the correlation between successive sampled states. HMC relies on the gradient of the logarithm of the posterior distribution, which we estimate using a stochastic ensemble method based on an ensemble of directional derivatives. SEM only requires forward <span class="hlt">model</span> runs and the simulator is then used as a black box and no adjoint code is needed. The developed HNS algorithm is successfully applied for Bayesian calibration and prior <span class="hlt">model</span> selection of several nonlinear subsurface flow problems.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2010AGUFM.A44D..04K','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2010AGUFM.A44D..04K"><span id="translatedtitle">Investigation of flow transition problems at WRFs <span class="hlt">nested</span>-domain interfaces</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Kirkil, G.; Mirocha, J.</p> <p>2010-12-01</p> <p>Many contemporary atmospheric simulation <span class="hlt">models</span> employ a grid <span class="hlt">nesting</span> capability that permits large-eddy simulations (LES) to be conducted over subsets of larger bounding simulations, with the bounding-domain solutions providing lateral boundary conditions for the <span class="hlt">nested</span> domains within. This approach can provide lateral boundary conditions that include <span class="hlt">mesoscale</span> features and the effects of upstream topography and land cover for the LES. Such an approach is particularly applicable to wind power forecasting, especially over complex terrain, for which <span class="hlt">mesoscale</span> flow conditions, local terrain effects and turbulence information can all be important. While grid <span class="hlt">nesting</span> has been successfully applied at GCM to <span class="hlt">mesoscale</span> resolutions, such <span class="hlt">nesting</span> behavior at higher resolutions, including those appropriate for LES, is less well understood. We investigate such grid <span class="hlt">nesting</span> capabilities for conducting an LES inside both larger-scale LES and <span class="hlt">mesoscale</span> simulations using the Weather Research and Forecasting (WRF) <span class="hlt">model</span>. Comparisons among the velocity and stress profiles inside the <span class="hlt">nested</span> domain relative to both the outer domain and non-<span class="hlt">nested</span> simulations indicate that errors contributed from the bounding domains are observed within the <span class="hlt">nested</span>-domain solution. We also examine the spatial scales required for flow structures to equilibrate to the finer mesh as flow enters a <span class="hlt">nest</span>, and how equilibration depends on several parameters, including mesh resolution and the type of turbulence subfilter-scale stress <span class="hlt">model</span> used. We outline approaches for addressing each of these issues, and provide progress to date. This work is performed under the auspices of the U.S. Department of Energy by Lawrence Livermore National Laboratory under Contract DE-AC52-07NA27344. LLNL-ABS-451371</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2015OcSci..11..667L&link_type=ABSTRACT','NASAADS'); return false;" href="http://adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2015OcSci..11..667L&link_type=ABSTRACT"><span id="translatedtitle"><span class="hlt">Mesoscale</span> variability in the Arabian Sea from HYCOM <span class="hlt">model</span> results and observations: impact on the Persian Gulf Water path</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>L'Hégaret, P.; Duarte, R.; Carton, X.; Vic, C.; Ciani, D.; Baraille, R.; Corréard, S.</p> <p>2015-09-01</p> <p>The Arabian Sea and Sea of Oman circulation and water masses, subject to monsoon forcing, reveal a strong seasonal variability and intense <span class="hlt">mesoscale</span> features. We describe and analyze this variability and these features, using both meteorological data (from ECMWF reanalyses), in situ observations (from the ARGO float program and the GDEM - Generalized Digital Environmental mode - climatology), satellite altimetry (from AVISO) and a regional simulation with a primitive equation <span class="hlt">model</span> (HYCOM - the Hybrid Coordinate Ocean <span class="hlt">Model</span>). The <span class="hlt">model</span> and observations display comparable variability, and the <span class="hlt">model</span> is then used to analyze the three-dimensional structure of eddies and water masses with higher temporal and spatial resolutions than the available observations. The <span class="hlt">mesoscale</span> features are highly seasonal, with the formation of coastal currents, destabilizing into eddies, or the radiation of Rossby waves from the Indian coast. The <span class="hlt">mesoscale</span> eddies have a deep dynamical influence and strongly drive the water masses at depth. In particular, in the Sea of Oman, the Persian Gulf Water presents several offshore ejection sites and a complex recirculation, depending on the <span class="hlt">mesoscale</span> eddies. The associated mechanisms range from coastal ejection via dipoles, alongshore pulses due to a cyclonic eddy, to the formation of lee eddies downstream of Ra's Al Hamra. This water mass is also captured inside the eddies via several mechanisms, keeping high thermohaline characteristics in the Arabian Sea. The variations of the outflow characteristics near the Strait of Hormuz are compared with variations downstream.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://cfpub.epa.gov/si/si_public_record_report.cfm?dirEntryId=146423&keyword=Michael+AND+Brown&actType=&TIMSType=+&TIMSSubTypeID=&DEID=&epaNumber=&ntisID=&archiveStatus=Both&ombCat=Any&dateBeginCreated=&dateEndCreated=&dateBeginPublishedPresented=&dateEndPublishedPresented=&dateBeginUpdated=&dateEndUpdated=&dateBeginCompleted=&dateEndCompleted=&personID=&role=Any&journalID=&publisherID=&sortBy=revisionDate&count=50&CFID=76933125&CFTOKEN=39151615','EPA-EIMS'); return false;" href="http://cfpub.epa.gov/si/si_public_record_report.cfm?dirEntryId=146423&keyword=Michael+AND+Brown&actType=&TIMSType=+&TIMSSubTypeID=&DEID=&epaNumber=&ntisID=&archiveStatus=Both&ombCat=Any&dateBeginCreated=&dateEndCreated=&dateBeginPublishedPresented=&dateEndPublishedPresented=&dateBeginUpdated=&dateEndUpdated=&dateBeginCompleted=&dateEndCompleted=&personID=&role=Any&journalID=&publisherID=&sortBy=revisionDate&count=50&CFID=76933125&CFTOKEN=39151615"><span id="translatedtitle">EXPERIMENTAL AND <span class="hlt">MODEL</span>-COMPUTED AREA AVERAGED VERTICAL PROFILES OF WIND SPEED FOR EVALUATION OF <span class="hlt">MESOSCALE</span> URBAN CANOPY SCHEMES</span></a></p> <p><a target="_blank" href="http://oaspub.epa.gov/eims/query.page">EPA Science Inventory</a></p> <p></p> <p></p> <p>Numerous urban canopy schemes have recently been developed for <span class="hlt">mesoscale</span> <span class="hlt">models</span> in order to approximate the drag and turbulent production effects of a city on the air flow. However, little data exists by which to evaluate the efficacy of the schemes since "area-averaged&quo...</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://cfpub.epa.gov/si/si_public_record_report.cfm?dirEntryId=257882&keyword=go&actType=&TIMSType=+&TIMSSubTypeID=&DEID=&epaNumber=&ntisID=&archiveStatus=Both&ombCat=Any&dateBeginCreated=&dateEndCreated=&dateBeginPublishedPresented=&dateEndPublishedPresented=&dateBeginUpdated=&dateEndUpdated=&dateBeginCompleted=&dateEndCompleted=&personID=&role=Any&journalID=&publisherID=&sortBy=revisionDate&count=50&CFID=77934621&CFTOKEN=77279243','EPA-EIMS'); return false;" href="http://cfpub.epa.gov/si/si_public_record_report.cfm?dirEntryId=257882&keyword=go&actType=&TIMSType=+&TIMSSubTypeID=&DEID=&epaNumber=&ntisID=&archiveStatus=Both&ombCat=Any&dateBeginCreated=&dateEndCreated=&dateBeginPublishedPresented=&dateEndPublishedPresented=&dateBeginUpdated=&dateEndUpdated=&dateBeginCompleted=&dateEndCompleted=&personID=&role=Any&journalID=&publisherID=&sortBy=revisionDate&count=50&CFID=77934621&CFTOKEN=77279243"><span id="translatedtitle">User’s manual for basic version of MCnest Markov chain <span class="hlt">nest</span> productivity <span class="hlt">model</span></span></a></p> <p><a target="_blank" href="http://oaspub.epa.gov/eims/query.page">EPA Science Inventory</a></p> <p></p> <p></p> <p>The Markov Chain <span class="hlt">Nest</span> Productivity <span class="hlt">Model</span> (or MCnest) integrates existing toxicity information from three standardized avian toxicity tests with information on species life history and the timing of pesticide applications relative to the timing of avian breeding seasons to quantit...</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://cfpub.epa.gov/si/si_public_record_report.cfm?dirEntryId=257881&keyword=go&actType=&TIMSType=+&TIMSSubTypeID=&DEID=&epaNumber=&ntisID=&archiveStatus=Both&ombCat=Any&dateBeginCreated=&dateEndCreated=&dateBeginPublishedPresented=&dateEndPublishedPresented=&dateBeginUpdated=&dateEndUpdated=&dateBeginCompleted=&dateEndCompleted=&personID=&role=Any&journalID=&publisherID=&sortBy=revisionDate&count=50&CFID=77934621&CFTOKEN=77279243','EPA-EIMS'); return false;" href="http://cfpub.epa.gov/si/si_public_record_report.cfm?dirEntryId=257881&keyword=go&actType=&TIMSType=+&TIMSSubTypeID=&DEID=&epaNumber=&ntisID=&archiveStatus=Both&ombCat=Any&dateBeginCreated=&dateEndCreated=&dateBeginPublishedPresented=&dateEndPublishedPresented=&dateBeginUpdated=&dateEndUpdated=&dateBeginCompleted=&dateEndCompleted=&personID=&role=Any&journalID=&publisherID=&sortBy=revisionDate&count=50&CFID=77934621&CFTOKEN=77279243"><span id="translatedtitle">Technical manual for basic version of the Markov chain <span class="hlt">nest</span> productivity <span class="hlt">model</span> (MCnest)</span></a></p> <p><a target="_blank" href="http://oaspub.epa.gov/eims/query.page">EPA Science Inventory</a></p> <p></p> <p></p> <p>The Markov Chain <span class="hlt">Nest</span> Productivity <span class="hlt">Model</span> (or MCnest) integrates existing toxicity information from three standardized avian toxicity tests with information on species life history and the timing of pesticide applications relative to the timing of avian breeding seasons to quantit...</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014JChPh.141k5101N','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014JChPh.141k5101N"><span id="translatedtitle">Thermomechanical stability and mechanochemical response of DNA: A minimal <span class="hlt">mesoscale</span> <span class="hlt">model</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Nisoli, Cristiano; Bishop, A. R.</p> <p>2014-09-01</p> <p>We show that a <span class="hlt">mesoscale</span> <span class="hlt">model</span>, with a minimal number of parameters, can well describe the thermomechanical and mechanochemical behavior of homogeneous DNA at thermal equilibrium under tension and torque. We predict critical temperatures for denaturation under torque and stretch, phase diagrams for stable DNA, probe/response profiles under mechanical loads, and the density of dsDNA as a function of stretch and twist. We compare our predictions with available single molecule manipulation experiments and find strong agreement. In particular we elucidate the difference between angularly constrained and unconstrained overstretching. We propose that the smoothness of the angularly constrained overstretching transition is a consequence of the molecule being in the vicinity of criticality for a broad range of values of applied tension.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2013AGUFMSA43C..07C','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2013AGUFMSA43C..07C"><span id="translatedtitle">The <span class="hlt">Mesoscale</span> Ionospheric Simulation Testbed (MIST) Regional Data Assimilation <span class="hlt">Model</span> (Invited)</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Comberiate, J.; Kelly, M. A.; Miller, E.; Paxton, L.</p> <p>2013-12-01</p> <p>The <span class="hlt">Mesoscale</span> Ionospheric Simulation Testbed (MIST) provides a regional nowcast and forecast of electron density values and has sufficient resolution to include equatorial plasma bubbles. The SSUSI instrument on the DMSP F18 satellite has high-resolution nightly observations of plasma bubbles at 8 PM local time throughout the current solar maximum. MIST can assimilate SSUSI UV observations, GPS TEC measurements, and SCINDA S4 readings simultaneously into a single scintillation map over a region of interest. MIST also <span class="hlt">models</span> ionospheric physics to provide a short-term UHF scintillation forecast based on assimilated data. We will present examples of electron density and scintillation maps from MIST. We will also discuss the potential to predict scintillation occurrence up to 6 hours in advance using observations of the equatorial arcs from SSUSI observations at 5:30 PM local time on the DMSP F17 satellite.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://ntrs.nasa.gov/search.jsp?R=20010072133&hterms=surface+temperature+measurement+error&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D30%26Ntt%3Dsurface%2Btemperature%2Bmeasurement%2Berror','NASA-TRS'); return false;" href="http://ntrs.nasa.gov/search.jsp?R=20010072133&hterms=surface+temperature+measurement+error&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D30%26Ntt%3Dsurface%2Btemperature%2Bmeasurement%2Berror"><span id="translatedtitle">Assimilation of Combined Microwave and Lightning Measurement in a <span class="hlt">Mesoscale</span> Weather Prediction <span class="hlt">Model</span></span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Chang, Dong-Eon; Weinman, James A.; Busalacchi, Antonio J. (Technical Monitor)</p> <p>2000-01-01</p> <p>Intermittent measurements of precipitation and integrated water vapor (IWV) distributions were retrieved from the Special Sensor Microwave/Imager (SSM/I) and Tropical Rainfall Measuring Mission (TRMM) Microwave Imager (TMI) radiometers. Lightning generates very low frequency (VLF) radio noise pulses called sferics. Those pulses propagate over large distances so that they can be continuously monitored with a sparse network of ground based radio receivers. Sferics data, tuned with intermittent spaceborne microwave radiometer data, were used to generate estimated rainfall that was assimilated into a <span class="hlt">mesoscale</span> weather prediction <span class="hlt">model</span>. Both continuous latent heating adjustment and a variational technique are applied as assimilation procedures to evaluate the impact of lightning observations on the forecast of an intense winter squall line over the Gulf of Mexico. Sensitivities to the assimilation of additional measurements such as IWV and sea surface temperature (SST), and measurement errors will also be discussed.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2005BAMS...86..961D','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2005BAMS...86..961D"><span id="translatedtitle">Multifunctional <span class="hlt">Mesoscale</span> Observing Networks.</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Dabberdt, Walter F.; Schlatter, Thomas W.; Carr, Frederick H.; Friday, Elbert W. Joe; Jorgensen, David; Koch, Steven; Pirone, Maria; Ralph, F. Martin; Sun, Juanzhen; Welsh, Patrick; Wilson, James W.; Zou, Xiaolei</p> <p>2005-07-01</p> <p>More than 120 scientists, engineers, administrators, and users met on 8 10 December 2003 in a workshop format to discuss the needs for enhanced three-dimensional <span class="hlt">mesoscale</span> observing networks. Improved networks are seen as being critical to advancing numerical and empirical <span class="hlt">modeling</span> for a variety of <span class="hlt">mesoscale</span> applications, including severe weather warnings and forecasts, hydrology, air-quality forecasting, chemical emergency response, transportation safety, energy management, and others. The participants shared a clear and common vision for the observing requirements: existing two-dimensional <span class="hlt">mesoscale</span> measurement networks do not provide observations of the type, frequency, and density that are required to optimize <span class="hlt">mesoscale</span> prediction and nowcasts. To be viable, <span class="hlt">mesoscale</span> observing networks must serve multiple applications, and the public, private, and academic sectors must all actively participate in their design and implementation, as well as in the creation and delivery of value-added products. The <span class="hlt">mesoscale</span> measurement challenge can best be met by an integrated approach that considers all elements of an end-to-end solution—identifying end users and their needs, designing an optimal mix of observations, defining the balance between static and dynamic (targeted or adaptive) sampling strategies, establishing long-term test beds, and developing effective implementation strategies. Detailed recommendations are provided pertaining to nowcasting, numerical prediction and data assimilation, test beds, and implementation strategies.<HR ALIGN="center" WIDTH="30%"></p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014PhDT.........3A','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014PhDT.........3A"><span id="translatedtitle"><span class="hlt">Mesoscale</span> <span class="hlt">Modeling</span> of Heterogeneous Materials Systems: From Solid Oxide Fuel Cells to Bulk Metallic Glasses</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Abdeljawad, Fadi F.</p> <p></p> <p>Heterogeneous materials systems hold the key to the future development of a broad range of increasingly complex technological applications. For example, multi-phase and/or multi-component materials are at the forefront research on the development of efficient energy devices, and the future generation of structural materials with optimal mechanical properties. In this dissertation, we focus on two materials systems, namely, solid oxide fuel cells (SOFCs) and bulk metallic glasses (BMGs), where we investigate, through theoretical and <span class="hlt">mesoscale</span> computational <span class="hlt">models</span>, the role of microstructure on the properties of these heterogeneous systems. For the solid oxide fuel cell project, a computational framework is developed to investigate the topological evolution of Ni phase in SOFC porous anodes, and the accompanying changes to a wide range of microstructural attributes that affect electrochemical performance. Additionally, with the aid of this framework, we study the reduction-oxidation instability, mechanical deformation and damage accumulation in SOFC anodes. In particular, the SOFC project is focused on the role of anode microstructure, characterized by particle size and ratio, on the microstructural stability and mechanical durability of SOFC anodes. For the bulk metallic glass project, a <span class="hlt">mesoscale</span> <span class="hlt">model</span> is introduced that accounts for the structural heterogeneity of monolithic BMGs and BMG composites, and captures the fundamental aspects of plastic deformation in such systems. We examine the effect of internal structure, characterized by rigid/soft short range order (SRO), on the deformation behavior of monolithic BMGs, while for BMG composites, we study the role of ductile phase microstructure, particle size, morphology and area fraction, on the mechanical properties and overall ductility of these systems.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015EGUGA..17.8128N','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015EGUGA..17.8128N"><span id="translatedtitle">Streamflow data assimilation for the <span class="hlt">mesoscale</span> hydrologic <span class="hlt">model</span> (mHM) using particle filtering</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Noh, Seong Jin; Rakovec, Oldrich; Kumar, Rohini; Samaniego, Luis; Choi, Shin-woo</p> <p>2015-04-01</p> <p>Data assimilation has been becoming popular to increase the certainty of the hydrologic prediction considering various sources of uncertainty through the hydrologic <span class="hlt">modeling</span> chain. In this study, we develop a data assimilation framework for the <span class="hlt">mesoscale</span> hydrologic <span class="hlt">model</span> (mHM 5.2, http://www.ufz.de/mhm) using particle filtering, which is a sequential DA method for non-linear and non-Gaussian <span class="hlt">models</span>. The mHM is a grid based distributed <span class="hlt">model</span> that is based on numerical approximations of dominant hydrologic processes having similarity with the HBV and VIC <span class="hlt">models</span>. The developed DA framework for the mHM represents simulation uncertainty by <span class="hlt">model</span> ensembles and updates spatial distributions of <span class="hlt">model</span> state variables when new observations are available in each updating time interval. The evaluation of the proposed method is carried out within several large European basins via assimilating multiple streamflow measurements in a daily interval. Dimensional limitations of particle filtering is resolved by effective noise specification methods, which uses spatial and temporal correlation of weather forcing data to represent <span class="hlt">model</span> structural uncertainty. The presentation will be focused on gains and limitations of streamflow data assimilation in several hindcasting experiments. In addition, impacts of non-Gaussian distributions of state variables on <span class="hlt">model</span> performance will be discussed.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2011HESSD...8.5165B','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2011HESSD...8.5165B"><span id="translatedtitle">A framework to utilize turbulent flux measurements for <span class="hlt">mesoscale</span> <span class="hlt">models</span> and remote sensing applications</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Babel, W.; Huneke, S.; Foken, T.</p> <p>2011-05-01</p> <p>Meteorologically measured fluxes of energy and matter between the surface and the atmosphere originate from a source area of certain extent, located in the upwind sector of the device. The spatial representativeness of such measurements is strongly influenced by the heterogeneity of the landscape. The footprint concept is capable of linking observed data with spatial heterogeneity. This study aims at upscaling eddy covariance derived fluxes to a grid size of 1 km edge length, which is typical for <span class="hlt">mesoscale</span> <span class="hlt">models</span> or low resolution remote sensing data. Here an upscaling strategy is presented, utilizing footprint <span class="hlt">modelling</span> and SVAT <span class="hlt">modelling</span> as well as observations from a target land-use area. The general idea of this scheme is to <span class="hlt">model</span> fluxes from adjacent land-use types and combine them with the measured flux data to yield a grid representative flux according to the land-use distribution within the grid cell. The performance of the upscaling routine is evaluated with real datasets, which are considered to be land-use specific fluxes in a grid cell. The measurements above rye and maize fields stem from the LITFASS experiment 2003 in Lindenberg, Germany and the respective <span class="hlt">modelled</span> timeseries were derived by the SVAT <span class="hlt">model</span> SEWAB. Contributions from each land-use type to the observations are estimated using a forward lagrangian stochastic <span class="hlt">model</span>. A representation error is defined as the error in flux estimates made when accepting the measurements unchanged as grid representative flux and ignoring flux contributions from other land-use types within the respective grid cell. Results show that this representation error can be reduced up to 56 % when applying the spatial integration. This shows the potential for further application of this strategy, although the absolute differences between flux observations from rye and maize were so small, that the spatial integration would be rejected in a real situation. Corresponding thresholds for this decision have been estimated as</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015EGUGA..17.2729C','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015EGUGA..17.2729C"><span id="translatedtitle">What can we learn from the hydrological <span class="hlt">modeling</span> of small-scale catchments for the discharge and water balance <span class="hlt">modeling</span> of <span class="hlt">mesoscale</span> catchments?</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Cornelissen, Thomas; Diekkrüger, Bernd; Bogena, Heye</p> <p>2015-04-01</p> <p>The application of 3D hydrological <span class="hlt">models</span> remains a challenge both in research and application studies because the parameterization not only depends on the amount and quality of data available for calibration and validation but also on the spatial and temporal <span class="hlt">model</span> resolution. In recent years, the <span class="hlt">model</span> parameterization has improved with the availability of high resolution data (e.g. eddy-covariance, wireless soil sensor networks). Unfortunately, these high resolution data are typically only available for small scale research test sites. This study aims to upscale the parameterization from a highly equipped, small-scale catchment to a <span class="hlt">mesoscale</span> catchment in order to reduce the parameterization uncertainty at that scale. The two <span class="hlt">nested</span> catchments chosen for the study are the 0.38 km² large spruce covered Wüstebach catchment and the 42 km² large Erkensruhr catchment characterized by a mixture of spruce and beech forest and grassland vegetation. The 3D hydrogeological <span class="hlt">model</span> HydroGeoSphere (HGS) has already been setup for the Wüstebach catchment in a previous study with a focus on the simulation performance of soil water dynamics and patterns. Thus, the parameterization process did not only optimize the water balance components but the catchment's wireless soil sensor network data were utilized to calibrate porosities in order to improve the simulation of soil moisture dynamics. In this study we compared different HGS <span class="hlt">model</span> realizations for the Erkensruhr catchment with different input data. For the first <span class="hlt">model</span> realization, the catchment is treated heterogeneous in terms of soil properties and topography but homogeneous with respect to land use, precipitation and potential evapotranspiration. For this case, the spruce forest parameterization and the climate input data were taken directly from the small-scale Wüstebach <span class="hlt">model</span> realization. Next, the calibrated soil porosity for the Wüstebach catchment is applied to the Erkensruhr. Further <span class="hlt">model</span> realizations</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2004ACPD....4.5455L&link_type=ABSTRACT','NASAADS'); return false;" href="http://adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2004ACPD....4.5455L&link_type=ABSTRACT"><span id="translatedtitle"><span class="hlt">Mesoscale</span> <span class="hlt">modeling</span> of combined aerosol and photo-oxidant processes in the eastern Mediterranean</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Lazaridis, M.; Spyridaki, A.; Solberg, S.; Smolík, J.; Ždímal, V.; Eleftheriadis, K.; Aleksandropoulou, V.; Hov, O.; Georgopoulos, P. G.</p> <p>2004-09-01</p> <p>Particulate matter and photo-oxidant processes in the Eastern Mediterranean have been studied using the UAM-AERO <span class="hlt">mesoscale</span> air quality <span class="hlt">model</span> in conjunction with the NILU-CTM regional <span class="hlt">model</span>. Meteorological data were obtained from the RAMS prognostic meteorological <span class="hlt">model</span>. The <span class="hlt">modeling</span> domain includes the eastern Mediterranean area between the Greek mainland and the island of Crete. The <span class="hlt">modeling</span> system is applied to study the atmospheric processes in three periods, i.e. 13-16 July 2000, 26-30 July 2000 and 7-14 January 2001. The spatial and temporal distributions of both gaseous and particulate matter pollutants have been extensively studied together with the identification of major emission sources in the area. The <span class="hlt">modeling</span> results were compared with field data obtained in the same period. Comparison of the <span class="hlt">modeling</span> results with measured data was performed for a number of gaseous and aerosol species. The UAM-AERO <span class="hlt">model</span> underestimates the PM10 measured concentrations during summer but better comparison has been obtained for the winter data.</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_10");'>10</a></li> <li><a href="#" onclick='return showDiv("page_11");'>11</a></li> <li class="active"><span>12</span></li> <li><a href="#" onclick='return showDiv("page_13");'>13</a></li> <li><a href="#" onclick='return showDiv("page_14");'>14</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_12 --> <div id="page_13" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_11");'>11</a></li> <li><a href="#" onclick='return showDiv("page_12");'>12</a></li> <li class="active"><span>13</span></li> <li><a href="#" onclick='return showDiv("page_14");'>14</a></li> <li><a href="#" onclick='return showDiv("page_15");'>15</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="241"> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2015MolPh.113..898M&link_type=ABSTRACT','NASAADS'); return false;" href="http://adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2015MolPh.113..898M&link_type=ABSTRACT"><span id="translatedtitle">Mucin aggregation from a rod-like <span class="hlt">meso-scale</span> <span class="hlt">model</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Moreno, Nicolas; Perilla, Jairo E.; Colina, Coray M.; Lísal, Martin</p> <p>2015-05-01</p> <p>Dissipative particle dynamics, a <span class="hlt">meso-scale</span> particle-based <span class="hlt">model</span>, was used to study the aggregation of mucins in aqueous solutions. Concentration, strength of the mucin-water interactions, as well as the effects of size, shape, and composition of the <span class="hlt">model</span> molecules were studied. <span class="hlt">Model</span> proteins were represented as rod-like objects formed by coarse-grained beads. In the first <span class="hlt">model</span>, only one type of beads formed the mucin. It was found that all the surfaces were available to form aggregates and the conformation of the aggregates was a function of the strength of the mucin-water interaction. With this <span class="hlt">model</span>, the number of aggregates was unaffected by the initial position of the mucins in the simulation box, except for the lowest mucin concentration. In a more refined mucin <span class="hlt">model</span>, two kinds of beads were used in the molecule in order to represent the existence of cysteine-like terminal groups in the actual molecule. With this new scheme, aggregation took place by the interaction of the terminal groups between <span class="hlt">model</span> molecules. The kinetic analysis of the evolution of the number of aggregates with time was also studied for both mucin <span class="hlt">models</span>.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/servlets/purl/5879503','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/servlets/purl/5879503"><span id="translatedtitle">MELSAR: a <span class="hlt">mesoscale</span> air quality <span class="hlt">model</span> for complex terrain. Volume 2. Appendices</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Allwine, K.J.; Whiteman, C.D.</p> <p>1985-04-01</p> <p>This final report is submitted as part of the Green River Ambient <span class="hlt">Model</span> Assessment (GRAMA) project conducted at the US Department of Energy's Pacific Northwest Laboratory for the US Environmental Protection Agency. The GRAMA Program has, as its ultimate goal, the development of validated air quality <span class="hlt">models</span> that can be applied to the complex terrain of the Green River Formation of western Colorado, eastern Utah and southern Wyoming. The Green River Formation is a geologic formation containing large reserves of oil shale, coal, and other natural resources. Development of these resources may lead to a degradation of the air quality of the region. Air quality <span class="hlt">models</span> are needed immediately for planning and regulatory purposes to assess the magnitude of these regional impacts. This report documents one of the <span class="hlt">models</span> being developed for this purpose within GRAMA - specifically a <span class="hlt">model</span> to predict short averaging time (less than or equal to 24 h) pollutant concentrations resulting from the <span class="hlt">mesoscale</span> transport of pollutant releases from multiple sources. MELSAR has not undergone any rigorous operational testing, sensitivity analyses, or validation studies. Testing and evaluation of the <span class="hlt">model</span> are needed to gain a measure of confidence in the <span class="hlt">model</span>'s performance. This report consists of two volumes. This volume contains the Appendices, which include listings of the FORTRAN code and Volume 1 contains the <span class="hlt">model</span> overview, technical description, and user's guide. 13 figs., 10 tabs.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/1990PhDT........91H','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/1990PhDT........91H"><span id="translatedtitle">a <span class="hlt">Mesoscale</span> Planetary Boundary Layer Numerical <span class="hlt">Model</span> for Simulations of Topographically Induced Circulations.</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Huang, Ching-Yuang Albert</p> <p>1990-01-01</p> <p>A <span class="hlt">mesoscale</span> planetary boundary layer (PBL) numerical <span class="hlt">model</span> is developed to investigate airflow over complex topography. The <span class="hlt">model</span> physics includes PBL turbulent transfer, atmospheric longwave and shortwave radiation, diurnal energy budgets over ground, cloud microphysics and subgrid cumulus parameterization. The <span class="hlt">model</span> utilizes a new fourth order Crowley advection scheme which preserves phase and amplitude much better than other Crowley schemes. Turbulence closures using the turbulent kinetic energy (TKE) and dissipation (varepsilon ) equations are investigated with the level 2.5 scheme of Mellor and Yamada (1982) to better determine eddy diffusivities. One-dimensional (1-D) <span class="hlt">model</span> results show that the PBL flows under various stability conditions are not significantly sensitive to the modified Blackadar's and Kolmogorov's eddy mixing length formations, although the latter yields excessively large mixing lengths in the entrainment region of the upper PBL. With the same prognostic TKE equation, the <span class="hlt">model</span> results show insensitivity of the 1-D flow to the details of diagnostic formulations in the closures and to eddy Prandtl numbers. A 2-D <span class="hlt">model</span> is used to stimulate January 28 cold -air outbreak over the Gulf Stream region during the IOP -2 (Intensive Observation Period) of the 1986 Genesis of Atlantic Lows Experiment (GALE). The <span class="hlt">modeled</span> 2-D circulation system is found to be sensitive to Prandtl number, in contrast to the 1-D <span class="hlt">model</span> results. Prandtl number becomes increasingly important as the clouds begin to interact with the marine boundary layer (MBL). Using the E-varepsilon closure, the <span class="hlt">model</span> predicts the observed MBL structure that includes a low level jet west of the Gulf Stream warm core and a constrained boundary layer height due to the middle-level stable layer. Two cases with 3-D idealized flow are also simulated for the same GALE IOP. For the easterly onshore ambient flow, a confluence zone appears near the coastline in response to the strong oceanic</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/20150002902','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20150002902"><span id="translatedtitle">High-Resolution <span class="hlt">Mesoscale</span> <span class="hlt">Model</span> Setup for the Eastern Range and Wallops Flight Facility</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Watson, Leela R.; Zavodsky, Bradley T.</p> <p>2015-01-01</p> <p><span class="hlt">Mesoscale</span> weather conditions can have an adverse effect on space launch, landing, ground processing, and weather advisories, watches, and warnings at the Eastern Range (ER) in Florida and Wallops Flight Facility (WFF) in Virginia. During summer, land-sea interactions across Kennedy Space Center (KSC) and Cape Canaveral Air Force Station (CCAFS) lead to sea breeze front formation, which can spawn deep convection that can hinder operations and endanger personnel and resources. Many other weak locally-driven low-level boundaries and their interactions with the sea breeze front and each other can also initiate deep convection in the KSC/CCAFS area. These convective processes often last 60 minutes or less and pose a significant challenge to the local forecasters. Surface winds during the transition seasons (spring and fall) pose the most difficulties for the forecasters at WFF. They also encounter problems forecasting convective activity and temperature during those seasons. Therefore, accurate <span class="hlt">mesoscale</span> <span class="hlt">model</span> forecasts are needed to better forecast a variety of unique weather phenomena. Global and national scale <span class="hlt">models</span> cannot properly resolve important local-scale weather features at each location due to their horizontal resolutions being much too coarse. Therefore, a properly tuned local data assimilation (DA) and forecast <span class="hlt">model</span> at a high resolution is needed to provide improved capability. To accomplish this, a number of sensitivity tests were performed using the Weather Research and Forecasting (WRF) <span class="hlt">model</span> in order to determine the best DA/<span class="hlt">model</span> configuration for operational use at each of the space launch ranges to best predict winds, precipitation, and temperature. A set of Perl scripts to run the Gridpoint Statistical Interpolation (GSI)/WRF in real-time were provided by NASA's Short-term Prediction Research and Transition Center (SPoRT). The GSI can analyze many types of observational data including satellite, radar, and conventional data. The GSI/WRF scripts</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015EGUGA..1713593K','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015EGUGA..1713593K"><span id="translatedtitle">Investigation of flow transition problems at WRFs <span class="hlt">nested</span>-domain interfaces</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Kirkil, Gokhan</p> <p>2015-04-01</p> <p>Many contemporary atmospheric simulation <span class="hlt">models</span> employ a grid <span class="hlt">nesting</span> capability that permits large-eddy simulations (LES) to be conducted over subsets of larger bounding simulations, with the bounding-domain solutions providing lateral boundary conditions for the <span class="hlt">nested</span> domains within. While grid <span class="hlt">nesting</span> has been successfully applied at GCM to <span class="hlt">mesoscale</span> resolutions, such <span class="hlt">nesting</span> behavior at higher resolutions, including those appropriate for LES, is less well understood. We investigate such grid <span class="hlt">nesting</span> capabilities for conducting an LES inside both larger-scale LES and <span class="hlt">mesoscale</span> simulations using the Weather Research and Forecasting (WRF) <span class="hlt">model</span>. Comparisons among the velocity and stress profiles inside the <span class="hlt">nested</span> domain relative to both the outer domain and non-<span class="hlt">nested</span> simulations indicate that errors contributed from the bounding domains are observed within the <span class="hlt">nested</span>-domain solution. We also examine the spatial scales required for flow structures to equilibrate to the finer mesh as flow enters a <span class="hlt">nest</span>, and how equilibration depends on several parameters, including mesh resolution and the type of turbulence subfilter-scale stress <span class="hlt">model</span> used.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/17500628','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/17500628"><span id="translatedtitle"><span class="hlt">Nested</span> incremental <span class="hlt">modeling</span> in the development of computational theories: the CDP+ <span class="hlt">model</span> of reading aloud.</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Perry, Conrad; Ziegler, Johannes C; Zorzi, Marco</p> <p>2007-04-01</p> <p>At least 3 different types of computational <span class="hlt">model</span> have been shown to account for various facets of both normal and impaired single word reading: (a) the connectionist triangle <span class="hlt">model</span>, (b) the dual-route cascaded <span class="hlt">model</span>, and (c) the connectionist dual process <span class="hlt">model</span>. Major strengths and weaknesses of these <span class="hlt">models</span> are identified. In the spirit of <span class="hlt">nested</span> incremental <span class="hlt">modeling</span>, a new connectionist dual process <span class="hlt">model</span> (the CDP+ <span class="hlt">model</span>) is presented. This <span class="hlt">model</span> builds on the strengths of 2 of the previous <span class="hlt">models</span> while eliminating their weaknesses. Contrary to the dual-route cascaded <span class="hlt">model</span>, CDP+ is able to learn and produce graded consistency effects. Contrary to the triangle and the connectionist dual process <span class="hlt">models</span>, CDP+ accounts for serial effects and has more accurate nonword reading performance. CDP+ also beats all previous <span class="hlt">models</span> by an order of magnitude when predicting individual item-level variance on large databases. Thus, the authors show that building on existing theories by combining the best features of previous <span class="hlt">models</span>--a <span class="hlt">nested</span> <span class="hlt">modeling</span> strategy that is commonly used in other areas of science but often neglected in psychology--results in better and more powerful computational <span class="hlt">models</span>. PMID:17500628</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/20150000384','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20150000384"><span id="translatedtitle">Range-Specific High-Resolution <span class="hlt">Mesoscale</span> <span class="hlt">Model</span> Setup: Data Assimilation</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Watson, Leela R.</p> <p>2014-01-01</p> <p><span class="hlt">Mesoscale</span> weather conditions can have an adverse effect on space launch, landing, and ground processing at the Eastern Range (ER) in Florida and Wallops Flight Facility (WFF) in Virginia. During summer, land-sea interactions across Kennedy Space Center (KSC) and Cape Canaveral Air Force Station (CCAFS) lead to sea breeze front formation, which can spawn deep convection that can hinder operations and endanger personnel and resources. Many other weak locally driven low-level boundaries and their interactions with the sea breeze front and each other can also initiate deep convection in the KSC/CCAFS area. Some of these other boundaries include the Indian River breeze front, Banana River breeze front, outflows from previous convection, horizontal convective rolls, convergence lines from other inland bodies of water such as Lake Okeechobee, the trailing convergence line from convergence of sea breeze fronts due to the shape of Cape Canaveral, frictional convergence lines from the islands in the Bahamas, convergence lines from soil moisture differences, convergence lines from cloud shading, and others. All these subtle weak boundary interactions often make forecasting of operationally important weather very difficult at KSC/CCAFS during the convective season (May-Oct). These convective processes often build quickly, last a short time (60 minutes or less), and occur over small distances, all of which also poses a significant challenge to the local forecasters who are responsible for issuing weather advisories, watches, and warnings. Surface winds during the transition seasons of spring and fall pose the most difficulties for the forecasters at WFF. They also encounter problems forecasting convective activity and temperature during those seasons. Therefore, accurate <span class="hlt">mesoscale</span> <span class="hlt">model</span> forecasts are needed to aid in their decision making. Both the ER and WFF would benefit greatly from high-resolution <span class="hlt">mesoscale</span> <span class="hlt">model</span> output to better forecast a variety of unique weather</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://cfpub.epa.gov/si/si_public_record_report.cfm?dirEntryId=234244&keyword=Winds&actType=&TIMSType=+&TIMSSubTypeID=&DEID=&epaNumber=&ntisID=&archiveStatus=Both&ombCat=Any&dateBeginCreated=&dateEndCreated=&dateBeginPublishedPresented=&dateEndPublishedPresented=&dateBeginUpdated=&dateEndUpdated=&dateBeginCompleted=&dateEndCompleted=&personID=&role=Any&journalID=&publisherID=&sortBy=revisionDate&count=50&CFID=64993251&CFTOKEN=39643336','EPA-EIMS'); return false;" href="http://cfpub.epa.gov/si/si_public_record_report.cfm?dirEntryId=234244&keyword=Winds&actType=&TIMSType=+&TIMSSubTypeID=&DEID=&epaNumber=&ntisID=&archiveStatus=Both&ombCat=Any&dateBeginCreated=&dateEndCreated=&dateBeginPublishedPresented=&dateEndPublishedPresented=&dateBeginUpdated=&dateEndUpdated=&dateBeginCompleted=&dateEndCompleted=&personID=&role=Any&journalID=&publisherID=&sortBy=revisionDate&count=50&CFID=64993251&CFTOKEN=39643336"><span id="translatedtitle">Examining Interior Grid Nudging Techniques Using Two-Way <span class="hlt">Nesting</span> in the WRF <span class="hlt">Model</span> for Regional Climate <span class="hlt">Modeling</span></span></a></p> <p><a target="_blank" href="http://oaspub.epa.gov/eims/query.page">EPA Science Inventory</a></p> <p></p> <p></p> <p>This study evaluates interior nudging techniques using the Weather Research and Forecasting (WRF) <span class="hlt">model</span> for regional climate <span class="hlt">modeling</span> over the conterminous United States (CONUS) using a two-way <span class="hlt">nested</span> configuration. NCEP–Department of Energy Atmospheric <span class="hlt">Model</span> Intercomparison Pro...</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2010ACPD...1025909F&link_type=ABSTRACT','NASAADS'); return false;" href="http://adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2010ACPD...1025909F&link_type=ABSTRACT"><span id="translatedtitle">Sensitivity of <span class="hlt">mesoscale</span> <span class="hlt">model</span> urban boundary layer meteorology to urban morphology</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Flagg, D. D.; Taylor, P. A.</p> <p>2010-11-01</p> <p><span class="hlt">Mesoscale</span> <span class="hlt">modeling</span> of the urban boundary layer requires careful parameterization of the surface due to its heterogeneous morphology. <span class="hlt">Model</span> estimated meteorological quantities, including the surface energy budget and canopy layer variables, will respond accordingly to the scale of representation. This study examines the sensitivity of the surface energy balance, canopy layer and boundary layer meteorology to the scale of urban surface representation in a real urban area (Detroit-Windsor (USA-Canada)) during several dry, cloud-free summer periods. The <span class="hlt">model</span> used is the Weather Research and Forecasting (WRF) <span class="hlt">model</span> with its coupled single-layer urban canopy <span class="hlt">model</span>. Some <span class="hlt">model</span> verification is presented using measurements from the Border Air Quality and Meteorology Study (BAQS-Met) 2007 field campaign and additional sources. Case studies span from "neighborhood" (10 s ~ 30 m) to very coarse (120 s ~ 3.7 km) resolution. Small changes in scale can affect the classification of the surface, affecting both the local and grid-average meteorology. Results indicate high sensitivity in turbulent latent heat flux from the natural surface and sensible heat flux from the urban canopy. Small scale change is also shown to delay timing of a lake-breeze front passage and can affect the timing of local transition in static stability.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2011ACP....11.2951F&link_type=ABSTRACT','NASAADS'); return false;" href="http://adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2011ACP....11.2951F&link_type=ABSTRACT"><span id="translatedtitle">Sensitivity of <span class="hlt">mesoscale</span> <span class="hlt">model</span> urban boundary layer meteorology to the scale of urban representation</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Flagg, D. D.; Taylor, P. A.</p> <p>2011-03-01</p> <p><span class="hlt">Mesoscale</span> <span class="hlt">modeling</span> of the urban boundary layer requires careful parameterization of the surface due to its heterogeneous morphology. <span class="hlt">Model</span> estimated meteorological quantities, including the surface energy budget and canopy layer variables, will respond accordingly to the scale of representation. This study examines the sensitivity of the surface energy balance, canopy layer and boundary layer meteorology to the scale of urban surface representation in a real urban area (Detroit-Windsor (USA-Canada)) during several dry, cloud-free summer periods. The <span class="hlt">model</span> used is the Weather Research and Forecasting (WRF) <span class="hlt">model</span> with its coupled single-layer urban canopy <span class="hlt">model</span>. Some <span class="hlt">model</span> verification is presented using measurements from the Border Air Quality and Meteorology Study (BAQS-Met) 2007 field campaign and additional sources. Case studies span from "neighborhood" (10 s ~308 m) to very coarse (120 s ~3.7 km) resolution. Small changes in scale can affect the classification of the surface, affecting both the local and grid-average meteorology. Results indicate high sensitivity in turbulent latent heat flux from the natural surface and sensible heat flux from the urban canopy. Small scale change is also shown to delay timing of a lake-breeze front passage and can affect the timing of local transition in static stability.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://ntrs.nasa.gov/search.jsp?R=20100031067&hterms=momentum&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D20%26Ntt%3Dmomentum','NASA-TRS'); return false;" href="http://ntrs.nasa.gov/search.jsp?R=20100031067&hterms=momentum&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D20%26Ntt%3Dmomentum"><span id="translatedtitle">Influence of Satellite-Based Heterogeneous Vegetation Momentum Roughness on <span class="hlt">Mesoscale</span> <span class="hlt">Model</span> Dynamics During IHOP 2002</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Jasinski, Michael; Eastman, Joseph; Borak, Jordan</p> <p>2010-01-01</p> <p>The sensitivity of <span class="hlt">mesoscale</span> weather prediction <span class="hlt">model</span> to a vegetation roughness initialization is investigated for the south central United States. Three different roughness databases are employed: i) a control or standard lookup table roughness that is a function only of land cover type, ii) a spatially heterogeneous roughness database previously derived using a physically based procedure and MODIS imagery, and iii) a MODIS climatologic roughness database that possesses the same spatial heterogeneity as (i) but with mean land class values from (ii). The <span class="hlt">model</span> used is the Weather Research and Forecast <span class="hlt">Model</span> (WRF) coupled to the Community Land <span class="hlt">Model</span> within the Land Information System (LIS). For each simulation, a statistical comparison is made between <span class="hlt">modeled</span> results and ground observations from meteorological stations within the Oklahoma mesonet and surrounding region during IHOP20O2. A sensitivity analysis on the impact the MODIS-based roughness fields is also made through a time-series intercomparison of temperature bias, probability of detection (POD), average wind speed, boundary layer height, and turbulent kinetic energy (TKE) the results that, for the current replacement of the standard land-cover type based roughness values with the satellite-derived fields statistically improves <span class="hlt">model</span> performance for most of the observed variables. Further, the satellite-based roughness enhances the surface wind speed, PBL height and TKE production on the order of 3 to l0 percent, with a lesser effect over grassland and cropland domains, and the greater effect over mixed land cover domains</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2014AGUFMEP11B..07C&link_type=ABSTRACT','NASAADS'); return false;" href="http://adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2014AGUFMEP11B..07C&link_type=ABSTRACT"><span id="translatedtitle">A new <span class="hlt">meso-scale</span> discrete element <span class="hlt">model</span> to study deposit differences in tsunamis and storms</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Cheng, W.; Weiss, R.</p> <p>2014-12-01</p> <p>A fundamental question in tsunami and storm studies is how to differentiate their deposits, which is key to the understanding of past events. Currently, there is no consistent differences due to wide variability of causative forces, topography, sediment source and post-depositional changes. One avenue to resolve these issues can potentially be numerical <span class="hlt">modeling</span>. Conventional depth-averaged <span class="hlt">models</span> help us learn general interactions between flow and sediments, but fail to reproduce small-scale depositional structures. We present a new <span class="hlt">meso-scale</span> sediment transport <span class="hlt">model</span>. The goal is to advance our knowledge of characteristic differences between storm and tsunami deposits and their relationship with the hydrodynamic processes in tsunamis and storms. Our transport <span class="hlt">model</span> is based on the Discrete Element Method (DEM). While it is ideal to <span class="hlt">model</span> every single sediment grains, contemporary computational power will be quickly exhausted due to the scale of interest. Therefore we employ the <span class="hlt">meso-scale</span> method where a particle represents a group of grains. The volume of each particle is determined dynamically based on pickup rate from the bed and transport rate at the boundaries. During transport, it is assumed that the particle does not change. The motion of particles is governed by Newton's Second Law, with wave motion superimposed on its settling velocities. Hindered settling is implemented to allow interactions between particles through changes of local sediment concentration. Particles are deposited when they reach the bed, and merged into the top layer. Deposits consist of layers that are of the same constant thickness. Bed avalanching could occur where slope exceeds a certain threshold. The Nonlinear Shallow Water Equation (NSWE) is employed to <span class="hlt">model</span> hydrodynamics. The system of NSWE is solved with a second-order upwind FVM numerical scheme. Wetting and drying is also implemented to handle inundation. In order to couple the depth integrated NSWE with DEM, a velocity</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2016CompM.tmp...69H&link_type=ABSTRACT','NASAADS'); return false;" href="http://adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2016CompM.tmp...69H&link_type=ABSTRACT"><span id="translatedtitle">An efficient FE-SBFE coupled method for <span class="hlt">mesoscale</span> cohesive fracture <span class="hlt">modelling</span> of concrete</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Huang, Y. J.; Yang, Z. J.; Liu, G. H.; Chen, X. W.</p> <p>2016-07-01</p> <p>This study develops a method coupling the finite element method (FEM) and the scaled boundary finite element method (SBFEM) for efficient <span class="hlt">meso-scale</span> fracture <span class="hlt">modelling</span> of concrete for the first time. In this method, the aggregates are <span class="hlt">modelled</span> by SBFE polygons with boundaries discretised only, while the mortar matrix is <span class="hlt">modelled</span> by conventional finite elements. The semi-analytical SBFEM is implemented in ABAQUS by a user-defined element subroutine for the first time. Nonlinear cohesive interface elements with normal and shear traction-separation constitutive laws are pre-inserted within the mortar and on the aggregate-mortar interfaces to simulate potential cracks. Various meso-structures generated from both random aggregates and X-ray computed tomography images are <span class="hlt">modelled</span>. The results demonstrate that the coupled method leads to considerable reductions in degrees of freedom and computational time against the conventional FEM, and these reductions become more significant when the aggregate volume fraction increases. The <span class="hlt">modelled</span> crack paths and load-carrying capacities of a three-point bending beam and an L-shaped panel are in excellent agreement with the experimental data.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015MNRAS.449.1664L','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015MNRAS.449.1664L"><span id="translatedtitle">Forecast of surface layer meteorological parameters at Cerro Paranal with a <span class="hlt">mesoscale</span> atmospherical <span class="hlt">model</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Lascaux, F.; Masciadri, E.; Fini, L.</p> <p>2015-05-01</p> <p>In this paper, we aim to prove the feasibility of the forecast of all the most relevant classical atmospherical parameters for astronomical applications (wind speed, wind direction, temperature) above the European Southern Observatory ground-based site of Cerro Paranal using a <span class="hlt">mesoscale</span> atmospherical <span class="hlt">model</span> called MESO-NH. In an earlier paper, we preliminarily treated the <span class="hlt">model</span> performances obtained in reconstructing some key atmospherical parameters in the surface layer 0-30 m, studying the bias and the root-mean-square error (RMSE) on a statistical sample of 20 nights. The results were very encouraging and therefore it appeared mandatory to confirm such good results on a much richer statistical sample. In this paper, the study has been extended to a total sample of 129 nights between 2007 and 2011, distributed in different parts of the solar year. This large sample made our analysis more robust and definitive in terms of the <span class="hlt">model</span> performances and permitted us to confirm the excellent performances of the <span class="hlt">model</span>. Besides, we present an independent analysis of the <span class="hlt">model</span> performances using the method of the contingency tables. Such a method permitted us to provide complementary key information with respect to the bias and the RMSE, which is particularly useful for an operational implementation of a forecast system.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/19950004194','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19950004194"><span id="translatedtitle">Comparison and analysis of aircraft measurements and <span class="hlt">mesoscale</span> atmospheric chemistry <span class="hlt">model</span> simulations of tropospheric ozone</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Pleim, Jonathan E.; Ching, Jason K. S.</p> <p>1994-01-01</p> <p>The Regional Acid Deposition <span class="hlt">Model</span> (RADM) has been applied to several of the field experiments which were part of the Acid <span class="hlt">Models</span> Operational and Diagnostic Evaluation Study (Acid MODES). The experiment which was of particular interest with regards to ozone photochemistry involved horizontal zig-zag flight patterns (ZIPPER) over an area from the eastern Ohio River valley to the Adirondacks of New York. <span class="hlt">Model</span> simulations by both the standard resolution RADM (delta x = 80 km) and the <span class="hlt">nested</span> grid RADM (delta x = 26.7 km) compare well to measurements in the low emission regions in central Pennsylvania and upstate New York, but underestimate in the high emission upper Ohio River valley. The <span class="hlt">nested</span> simulation does considerably better, however, than the coarse grid simulation in terms of horizontal pattern and concentration magnitudes. Analysis of NO(x) and HO(x) concentrations and photochemical products rates of ozone show that the <span class="hlt">model</span>'s response to large point source emissions is very unsystematic both spatially and temporally. This is due to the <span class="hlt">models</span> instability to realistically simulate the small scale (subgrid) gradients in precursor concentrations in and around large point source plumes.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/20120002859','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20120002859"><span id="translatedtitle">An OSSE on <span class="hlt">Mesoscale</span> <span class="hlt">Model</span> Assimilation of Simulated HIRAD-Observed Hurricane Surface Winds</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Albers, Cerese; Miller, Timothy; Uhlhorn, Eric; Krishnamurti, T. N.</p> <p>2012-01-01</p> <p>The hazards of landfalling hurricanes are well known, but progress on improving the intensity forecasts of these deadly storms at landfall has been slow. Many cite a lack of high-resolution data sets taken inside the core of a hurricane, and the lack of reliable measurements in extreme conditions near the surface of hurricanes, as possible reasons why even the most state-of-the-art forecasting <span class="hlt">models</span> cannot seem to forecast intensity changes better. The Hurricane Imaging Radiometer (HIRAD) is a new airborne microwave remote sensor for observing hurricanes, and is operated and researched by NASA Marshall Space Flight Center in partnership with the NOAA Atlantic Oceanographic and Meteorological Laboratory/Hurricane Research Division, the University of Central Florida, the University of Michigan, and the University of Alabama in Huntsville. This instrument?s purpose is to study the wind field of a hurricane, specifically observing surface wind speeds and rain rates, in what has traditionally been the most difficult areas for other instruments to study; the high wind and heavy rain regions. Dr. T. N. Krishnamurti has studied various data assimilation techniques for hurricane and monsoon rain rates, and this study builds off of results obtained from utilizing his style of physical initializations of rainfall observations, but obtaining reliable observations in heavy rain regions has always presented trouble to our research of high-resolution rainfall forecasting. Reliable data from these regions at such a high resolution and wide swath as HIRAD provides is potentially very valuable to <span class="hlt">mesoscale</span> forecasting of hurricane intensity. This study shows how the data assimilation technique of Ensemble Kalman Filtering (EnKF) in the Weather Research and Forecasting (WRF) <span class="hlt">model</span> can be used to incorporate wind, and later rain rate, data into a <span class="hlt">mesoscale</span> <span class="hlt">model</span> forecast of hurricane intensity. The study makes use of an Observing System Simulation Experiment (OSSE) with a simulated</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://ntrs.nasa.gov/search.jsp?R=19890031821&hterms=breeze&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D20%26Ntt%3Dbreeze','NASA-TRS'); return false;" href="http://ntrs.nasa.gov/search.jsp?R=19890031821&hterms=breeze&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D20%26Ntt%3Dbreeze"><span id="translatedtitle">Providing operational guidance for the development of sea breeze thunderstorms at the Kennedy Space Center - An experiment using a <span class="hlt">mesoscale</span> numerical <span class="hlt">model</span></span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Lyons, Walter A.; Moon, Dennis A.; Keen, Cecil S.; Schuh, Jerome A.; Pielke, Roger A.</p> <p>1988-01-01</p> <p>The effectiveness of a <span class="hlt">mesoscale</span> numerical <span class="hlt">model</span> to provide improved local forecast guidance is evaluated with respect to sea breeze convection storms at the Kennedy Space Center. The <span class="hlt">model</span> and operational forecast guidance production are described. A case study is presented for sea breeze convection storms and lightning events on July 1, 1986. It is found that the <span class="hlt">mesoscale</span> numerical <span class="hlt">model</span> outperforms purely subjective predictions of sea breeze convection. The range of applications for the <span class="hlt">model</span> are considered.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2003AtmEn..37.2451V','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2003AtmEn..37.2451V"><span id="translatedtitle">A <span class="hlt">mesoscale</span> <span class="hlt">modeling</span> study of wind blown dust on the Mexico City Basin</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Villasenor, Rafael; López-Villegas, M. T.; Eidels-Dubovoi, S.; Quintanar, Arturo; Gallardo, J. C.</p> <p></p> <p>The latest phase of the program to improve the air quality in the Valley of Mexico, also known, as Pro Aire is about to go into effect for the next 10 years. Pro Aire puts emphasis on agricultural wind erosion and associated dust emissions impacting downwind air quality. The main objective of this investigation was to use an empirical USEPA erosion <span class="hlt">model</span> coupled to a meteorological/transport-dispersion prediction <span class="hlt">model</span>, CALMET/CALPUFF, to estimate dust emissions and concentrations in the Mexico City Basin. The <span class="hlt">model</span> simulations for particulate matter (PM 10) are validated against observations taken at the most recent research field study, the IMADA-AVER field campaign, conducted during the spring of 1997 to provide information about high ozone, particulate matter concentrations and visibility impairment. The spatial and temporal PM distribution in the region is presented for a specific wind blown dust event consisting of two IMADA days, in order to understand how soil dust emissions from agricultural fallow land affect downwind areas during the dry season. Results show good agreement with the main spatial features of the local wind circulation and wind blown dust concentrations. A correlation coefficient of nearly 0.8 between predictions and observations for a <span class="hlt">modeled</span> day suggests that an important portion of the total measured concentration had geological origin. This work constitutes an essential advancement on the <span class="hlt">mesoscale</span> air quality problem on the MCMA due to wind erosion.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015AGUFM.A53G..05J','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015AGUFM.A53G..05J"><span id="translatedtitle">Air-sea Energy Transfer at <span class="hlt">Mesoscale</span> in a Coupled High-resolution <span class="hlt">Model</span>: Impact of Resolution and Current Feedback</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Jullien, S.; Colas, F.; Masson, S. G.; Oerder, V.; Echevin, V.; Samson, G.; Crétat, J.; Berthet, S.; Hourdin, C.</p> <p>2015-12-01</p> <p>Winds are usually considered to force the ocean but recent studies suggested that oceanic <span class="hlt">mesoscale</span> activity, characterized by eddies, filaments and fronts, could also affect the wind field. These structures feature abrupt changes in sea surface temperature (SST), surface pressure and surface currents that could impact the atmosphere by enhancing/reducing air-sea fluxes, accelerating/decelerating winds, modifying the wind-pressure balance… At this time, the detailed processes associated to such coupling, its intensity and significance remain a matter of research. Here, a state-of-the-art WRF-OASIS-NEMO coupled <span class="hlt">model</span> is set up over a wide tropical channel (45°S-45°N) at various resolutions: 3/4°, 1/4° and 1/12° in both the ocean and the atmosphere. Several experiments are conducted in forced, partially or fully coupled modes, to highlight the effect of resolution and the role of SST vs. current feedback to energy injection into the ocean and the atmosphere. In strong <span class="hlt">mesoscale</span> activity regions, a negative wind power input from the atmosphere to the ocean is seen at scales ranging from 100km to more than 1000km. Nonexistent at 3/4°, this negative forcing, acting against oceanic <span class="hlt">mesoscale</span> activity, is almost twice more important at 1/12° than at 1/4°. In addition, partially coupled simulations, i.e. without current feedback, show that the impact of thermal coupling on this process is very limited. Energy injection to the marine atmospheric boundary layer also features imprints from oceanic <span class="hlt">mesoscale</span>. Energy injection by scales shorter than 300km represents up to 20% of the total. Finally we show that increasing oceanic resolution, and therefore <span class="hlt">mesoscale</span> activity, is necessary to resolve the full wind stress spectrum and has an upscaling effect by enhancing atmospheric <span class="hlt">mesoscale</span>, which is larger scale than in the ocean. Using 1/4°oceanic resolution instead of 1/12° leads to a 50% loss of energy in the atmospheric <span class="hlt">mesoscale</span>.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://ntrs.nasa.gov/search.jsp?R=19930055785&hterms=breeze&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D20%26Ntt%3Dbreeze','NASA-TRS'); return false;" href="http://ntrs.nasa.gov/search.jsp?R=19930055785&hterms=breeze&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D20%26Ntt%3Dbreeze"><span id="translatedtitle">Final results of an experiment in operational forecasting of sea breeze thunderstorms using a <span class="hlt">mesoscale</span> numerical <span class="hlt">model</span></span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Lyons, Walter A.; Pielke, Roger A.; Cotton, William R.; Keen, Cecil S.; Moon, Dennis A.</p> <p>1992-01-01</p> <p>Sea breeze thunderstorms during quiescent synoptic conductions account for 40 percent of Florida rainfall, and are the dominant feature of April-October weather at the Kennedy Space Center (KSC). An effort is presently made to assess the feasibility of a <span class="hlt">mesoscale</span> numerical <span class="hlt">model</span> in improving the point-specific thunderstorm forecasting accuracy at the KSC, in the 2-12 hour time frame. Attention is given to the Applied Regional Atmospheric <span class="hlt">Modeling</span> System.</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_11");'>11</a></li> <li><a href="#" onclick='return showDiv("page_12");'>12</a></li> <li class="active"><span>13</span></li> <li><a href="#" onclick='return showDiv("page_14");'>14</a></li> <li><a href="#" onclick='return showDiv("page_15");'>15</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_13 --> <div id="page_14" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_12");'>12</a></li> <li><a href="#" onclick='return showDiv("page_13");'>13</a></li> <li class="active"><span>14</span></li> <li><a href="#" onclick='return showDiv("page_15");'>15</a></li> <li><a href="#" onclick='return showDiv("page_16");'>16</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="261"> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2007PApGe.164.1161G','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2007PApGe.164.1161G"><span id="translatedtitle">Microphysical Observations and <span class="hlt">Mesoscale</span> <span class="hlt">Model</span> Simulation of a Warm Fog Case during FRAM Project</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Gultepe, I.; Milbrandt, J. A.</p> <p>2007-06-01</p> <p>The objective of this work is to apply a new microphysical parameterization for fog visibility for potential use in numerical weather forecast simulations, and to compare the results with ground-based observations. The observations from the Fog Remote Sensing And <span class="hlt">Modeling</span> (FRAM) field which took place during the winter of 2005 2006 over southern Ontario, Canada (Phase I) were used in the analysis. The liquid water content (LWC), droplet number concentration (N d ), and temperature (T) were obtained from the fog measuring device (FMD) spectra and Rosemount probe, correspondingly. The visibility (Vis) from a visibility meter, liquid water path from microwave radiometers (MWR), and inferred fog properties such as mean volume diameter, LWC, and N d were also used in the analysis. The results showed that Vis is nonlinearly related to both LWC and N d . Comparisons between newly derived parameterizations and the ones already in use as a function of LWC suggested that if <span class="hlt">models</span> can predict the total N d and LWC at each time step using a detailed microphysics parameterization, Vis can then be calculated for warm fog conditions. Using outputs from the Canadian <span class="hlt">Mesoscale</span> Compressible Community (MC2) <span class="hlt">model</span>, being tested with a new multi-moment bulk microphysical scheme, the new Vis parameterization resulted in more accurate Vis values where the correction reached up to 20 50%.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015TESS....121104S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015TESS....121104S"><span id="translatedtitle"><span class="hlt">Modeling</span> of <span class="hlt">mesoscale</span> flux-tube interchange motions in the inner magnetosphere</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Sazykin, Stanislav; Wolf, Richard Alan; Yang, Jian; Rocco Toffoletto, Frank</p> <p>2015-04-01</p> <p><span class="hlt">Mesoscale</span> flux-tube interchange motions associated with bursty bulk flows and dipolarization fronts play a significant role in particle transport from the plasma sheet into the inner magnetosphere. One of the challenges is to quantify the relative role of these processes compared to large-scale particle energization as part of global-scale convection. In this paper, we will describe latest progress in attempting quantitative <span class="hlt">modeling</span> of flux-tube interchange processes using a high-resolution version of the Rice Convection <span class="hlt">Model</span> (RCM) that includes effects of inertial drifts. Including effects of inertial drifts is necessary to allow oscillatory motion of flux tubes in inner magnetospheric <span class="hlt">models</span>. We generalized the formulation of the RCM by making three simplifying assumptions: (i) the communication between the equatorial plane and ionosphere occurs either instantaneously or with a given time lag, (ii) the pressure is isotropic and therefore constant along field lines, and (iii) for purposes of calculating the effect of inertia, all of a flux tube's mass is assumed to be concentrated in the equatorial plane. We will present idealized numerical simulations of a depleted flux tube propagation in the magnetosphere, and quantify particle injection signatures. Our analysis of the simulations will include ionospheric electric fields and particle precipitation signatures of the flow channels associated with propagation of depleted flux tubes, and address the sensitivity of the results to the assumptions made in the inclusion of the inertia effects.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/servlets/purl/840972','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/servlets/purl/840972"><span id="translatedtitle">Multiphase <span class="hlt">Modeling</span> of Flow, Transport, and Biodegradation in a <span class="hlt">Mesoscale</span> Landfill Bioreactor</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Oldenburg, Curtis M.; Borglin, Sharon E.; Hazen, Terry C.</p> <p>2002-02-01</p> <p>The need to control gas and leachate production and minimize refuse volume in municipal solid waste landfills has motivated the development of landfill simulation <span class="hlt">models</span> to predict and design optimal treatment processes. We have developed a multiphase and multicomponent nonisothermal module called T2LBM for the three-dimensional TOUGH2 flow and transport simulator. T2LBM can be used to simulate aerobic or anaerobic biodegradation of municipal solid waste and the associated flow and transport of gas and liquid through the refuse mass. Acetic acid is used as a proxy for all biodegradable substrates in the refuse. T2LBM incorporates a Monod kinetic rate law for the biodegradation of acetic acid by either aerobic or anaerobic microbes as controlled by the local oxygen concentration. We have verified the <span class="hlt">model</span> against published data, and applied it to our own <span class="hlt">mesoscale</span> laboratory aerobic landfill bioreactor experiments. We observe spatial variability of flow and biodegradation consistent with permeability heterogeneity and the geometry of the radial grid. The <span class="hlt">model</span> is capable of matching results of a shut-in test where the respiration of the system is measured over time.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2006AGUFM.A32D..08N','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2006AGUFM.A32D..08N"><span id="translatedtitle">Dissecting the 7 July 2004 storm over Baltimore, MD: <span class="hlt">Mesoscale</span> <span class="hlt">modeling</span> and observations</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Ntelekos, A. A.; Smith, J. A.; Baeck, M. L.; Miller, A. J.</p> <p>2006-12-01</p> <p>On 7 July 2004, the Baltimore metropolitan region experienced a thunderstorm system that produced record flooding, rainfall and cloud-to-ground lightning strikes. In this study, <span class="hlt">model</span> and observational analyses are carried out to analyze the hydrometeorology of the storm and understand the impacts of the urban environment and surrounding topography on storm evolution. Baltimore is an interesting setting for these analyses combining the urban environment with mountainous terrain to the west and the land-water interface to the east. Hydrometeorological analyses are based on volume scan reflectivity observations from the Baltimore International Airport Terminal Doppler Weather Radar and the Sterling, Virginia WSR-88D radar, cloud-to- ground lightning observations from the National Lightning Detection Network, raindrop spectra observations from a Joss-Waldvogel disdrometer and rainfall accumulations from a dense rain gage network operated as a component of the Baltimore Ecosystem Study. Numerical <span class="hlt">model</span> analyses use the Weather Research Forecast (WRF) <span class="hlt">mesoscale</span> <span class="hlt">model</span> to examine the impact of land-use, topography and land-water boundaries on the initiation and evolution of the storm.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2003PApGe.160..429R','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2003PApGe.160..429R"><span id="translatedtitle">Three-dimensional Simulations of the Mean Air Transport During the 1997 Forest Fires in Kalimantan, Indonesia Using a <span class="hlt">Mesoscale</span> Numerical <span class="hlt">Model</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Roswintiarti, O.; Raman, S.</p> <p></p> <p>- This paper describes the meteorological processes responsible for the mean transport of air pollutants during the ENSO-related forest fires in Kalimantan, Indonesia from 00 UTC 21 September to 00 UTC 25 September, 1997. The Fifth Generation of the Pennsylvania State University-National Center for Atmospheric Research (PSU-NCAR) <span class="hlt">Mesoscale</span> <span class="hlt">Model</span> (MM5) is used to simulate three-dimensional winds at 6-hourly intervals. A nonhydrostatic version of the <span class="hlt">model</span> is run using two <span class="hlt">nested</span> grids with horizontal resolutions of 45 km and 15 km. From the simulated wind fields, the backward and forward trajectories of the air parcel are investigated using the Vis5D <span class="hlt">model</span>.The results indicate that the large-scale subsidence over Indonesia, the southwest monsoon low-level flows (2-8 m s-1), and the shallow planetary boundary layer height (400-800 m) play a key role in the transport of air pollutants from Kalimantan to Malaysia, Singapore and Brunei.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2012AtmRe.116..161L','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2012AtmRe.116..161L"><span id="translatedtitle">Numerical simulation of severe local storms over east India using WRF-NMM <span class="hlt">mesoscale</span> <span class="hlt">model</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Litta, A. J.; Mohanty, U. C.; Das, Someshwar; Mary Idicula, Sumam</p> <p>2012-10-01</p> <p>A common feature of the weather during the pre-monsoon season (March-May) over the east and northeast India is the outburst of severe local storms which have significant socio-economic impact due to loss of lives and properties. Forecasting thunderstorms is one of the most difficult tasks in weather prediction, due to their rather small spatial and temporal scales and the inherent non-linearity of their dynamics and physics. In the present study, an attempt has been made to simulate severe local storms that occurred over east India during STORM field experiments 2007, 2009 and 2010, using Non-hydrostatic <span class="hlt">Mesoscale</span> <span class="hlt">Model</span> (NMM) and validate the <span class="hlt">model</span> results with observation. This study shows that the NMM <span class="hlt">model</span> holds better promise for prediction of thunderstorm with reasonable accuracy. The intensity of rainfall rates is in good agreement with the observation. The <span class="hlt">model</span> has well captured the stability indices, which act as indicators of severe convective activity. The surface temperature and relative humidity over Kolkata are reasonably well simulated by the NMM <span class="hlt">model</span> even though one hour time lag or lead exists. The <span class="hlt">model</span> simulated well the updraft and downdraft over Kolkata, which is an important phenomenon related to thunderstorm life cycle. From the <span class="hlt">model</span> simulated spatial plots of composite radar reflectivity and cloud top temperature, we can see that the <span class="hlt">model</span> has also been able to capture the movement of thunder squall. The results of these analyses determined that the 3 km WRF-NMM <span class="hlt">model</span> has good skill when it comes to the thunderstorm simulation.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/biblio/1287335','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/biblio/1287335"><span id="translatedtitle">An atomistically informed <span class="hlt">mesoscale</span> <span class="hlt">model</span> for growth and coarsening during discharge in lithium-oxygen batteries</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Welland, Michael J.; Lau, Kah Chun; Redfern, Paul C.; Liang, Linyun; Zhai, Denyun; Wolf, Dieter; Curtiss, Larry A.</p> <p>2015-12-14</p> <p>An atomistically informed <span class="hlt">mesoscale</span> <span class="hlt">model</span> is developed for the deposition of a discharge product in a Li-O-2 battery. This mescocale <span class="hlt">model</span> includes particle growth and coarsening as well as a simplified nucleation <span class="hlt">model</span>. The <span class="hlt">model</span> involves LiO2 formation through reaction of O-2(-) and Li+ in the electrolyte, which deposits on the cathode surface when the LiO2 concentration reaches supersaturation in the electrolyte. A reaction-diffusion (rate-equation) <span class="hlt">model</span> is used to describe the processes occurring in the electrolyte and a phase-field <span class="hlt">model</span> is used to capture microstructural evolution. This <span class="hlt">model</span> predicts that coarsening, in which large particles grow and small ones disappear, has a substantial effect on the size distribution of the LiO2 particles during the discharge process. The size evolution during discharge is the result of the interplay between this coarsening process and particle growth. The growth through continued deposition of LiO2 has the effect of causing large particles to grow ever faster while delaying the dissolution of small particles. The predicted size evolution is consistent with experimental results for a previously reported cathode material based on activated carbon during discharge and when it is at rest, although kinetic factors need to be included. The approach described in this paper synergistically combines <span class="hlt">models</span> on different length scales with experimental observations and should have applications in studying other related discharge processes, such as Li2O2 deposition, in Li-O-2 batteries and nucleation and growth in Li-S batteries.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/26671364','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/26671364"><span id="translatedtitle">An atomistically informed <span class="hlt">mesoscale</span> <span class="hlt">model</span> for growth and coarsening during discharge in lithium-oxygen batteries.</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Welland, Michael J; Lau, Kah Chun; Redfern, Paul C; Liang, Linyun; Zhai, Denyun; Wolf, Dieter; Curtiss, Larry A</p> <p>2015-12-14</p> <p>An atomistically informed <span class="hlt">mesoscale</span> <span class="hlt">model</span> is developed for the deposition of a discharge product in a Li-O2 battery. This mescocale <span class="hlt">model</span> includes particle growth and coarsening as well as a simplified nucleation <span class="hlt">model</span>. The <span class="hlt">model</span> involves LiO2 formation through reaction of O2(-) and Li(+) in the electrolyte, which deposits on the cathode surface when the LiO2 concentration reaches supersaturation in the electrolyte. A reaction-diffusion (rate-equation) <span class="hlt">model</span> is used to describe the processes occurring in the electrolyte and a phase-field <span class="hlt">model</span> is used to capture microstructural evolution. This <span class="hlt">model</span> predicts that coarsening, in which large particles grow and small ones disappear, has a substantial effect on the size distribution of the LiO2 particles during the discharge process. The size evolution during discharge is the result of the interplay between this coarsening process and particle growth. The growth through continued deposition of LiO2 has the effect of causing large particles to grow ever faster while delaying the dissolution of small particles. The predicted size evolution is consistent with experimental results for a previously reported cathode material based on activated carbon during discharge and when it is at rest, although kinetic factors need to be included. The approach described in this paper synergistically combines <span class="hlt">models</span> on different length scales with experimental observations and should have applications in studying other related discharge processes, such as Li2O2 deposition, in Li-O2 batteries and nucleation and growth in Li-S batteries. PMID:26671364</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015JChPh.143v4113W','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015JChPh.143v4113W"><span id="translatedtitle">An atomistically informed <span class="hlt">mesoscale</span> <span class="hlt">model</span> for growth and coarsening during discharge in lithium-oxygen batteries</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Welland, Michael J.; Lau, Kah Chun; Redfern, Paul C.; Liang, Linyun; Zhai, Denyun; Wolf, Dieter; Curtiss, Larry A.</p> <p>2015-12-01</p> <p>An atomistically informed <span class="hlt">mesoscale</span> <span class="hlt">model</span> is developed for the deposition of a discharge product in a Li-O2 battery. This mescocale <span class="hlt">model</span> includes particle growth and coarsening as well as a simplified nucleation <span class="hlt">model</span>. The <span class="hlt">model</span> involves LiO2 formation through reaction of O2- and Li+ in the electrolyte, which deposits on the cathode surface when the LiO2 concentration reaches supersaturation in the electrolyte. A reaction-diffusion (rate-equation) <span class="hlt">model</span> is used to describe the processes occurring in the electrolyte and a phase-field <span class="hlt">model</span> is used to capture microstructural evolution. This <span class="hlt">model</span> predicts that coarsening, in which large particles grow and small ones disappear, has a substantial effect on the size distribution of the LiO2 particles during the discharge process. The size evolution during discharge is the result of the interplay between this coarsening process and particle growth. The growth through continued deposition of LiO2 has the effect of causing large particles to grow ever faster while delaying the dissolution of small particles. The predicted size evolution is consistent with experimental results for a previously reported cathode material based on activated carbon during discharge and when it is at rest, although kinetic factors need to be included. The approach described in this paper synergistically combines <span class="hlt">models</span> on different length scales with experimental observations and should have applications in studying other related discharge processes, such as Li2O2 deposition, in Li-O2 batteries and nucleation and growth in Li-S batteries.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/biblio/22493306','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/biblio/22493306"><span id="translatedtitle">An atomistically informed <span class="hlt">mesoscale</span> <span class="hlt">model</span> for growth and coarsening during discharge in lithium-oxygen batteries</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Welland, Michael J.; Lau, Kah Chun; Redfern, Paul C.; Wolf, Dieter; Curtiss, Larry A.; Liang, Linyun; Zhai, Denyun</p> <p>2015-12-14</p> <p>An atomistically informed <span class="hlt">mesoscale</span> <span class="hlt">model</span> is developed for the deposition of a discharge product in a Li-O{sub 2} battery. This mescocale <span class="hlt">model</span> includes particle growth and coarsening as well as a simplified nucleation <span class="hlt">model</span>. The <span class="hlt">model</span> involves LiO{sub 2} formation through reaction of O{sub 2}{sup −} and Li{sup +} in the electrolyte, which deposits on the cathode surface when the LiO{sub 2} concentration reaches supersaturation in the electrolyte. A reaction-diffusion (rate-equation) <span class="hlt">model</span> is used to describe the processes occurring in the electrolyte and a phase-field <span class="hlt">model</span> is used to capture microstructural evolution. This <span class="hlt">model</span> predicts that coarsening, in which large particles grow and small ones disappear, has a substantial effect on the size distribution of the LiO{sub 2} particles during the discharge process. The size evolution during discharge is the result of the interplay between this coarsening process and particle growth. The growth through continued deposition of LiO{sub 2} has the effect of causing large particles to grow ever faster while delaying the dissolution of small particles. The predicted size evolution is consistent with experimental results for a previously reported cathode material based on activated carbon during discharge and when it is at rest, although kinetic factors need to be included. The approach described in this paper synergistically combines <span class="hlt">models</span> on different length scales with experimental observations and should have applications in studying other related discharge processes, such as Li{sub 2}O{sub 2} deposition, in Li-O{sub 2} batteries and nucleation and growth in Li-S batteries.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://eric.ed.gov/?q=depression+AND+adolescence&pg=2&id=EJ1004545','ERIC'); return false;" href="http://eric.ed.gov/?q=depression+AND+adolescence&pg=2&id=EJ1004545"><span id="translatedtitle">Comparing Regression Coefficients between <span class="hlt">Nested</span> Linear <span class="hlt">Models</span> for Clustered Data with Generalized Estimating Equations</span></a></p> <p><a target="_blank" href="http://www.eric.ed.gov/ERICWebPortal/search/extended.jsp?_pageLabel=advanced">ERIC Educational Resources Information Center</a></p> <p>Yan, Jun; Aseltine, Robert H., Jr.; Harel, Ofer</p> <p>2013-01-01</p> <p>Comparing regression coefficients between <span class="hlt">models</span> when one <span class="hlt">model</span> is <span class="hlt">nested</span> within another is of great practical interest when two explanations of a given phenomenon are specified as linear <span class="hlt">models</span>. The statistical problem is whether the coefficients associated with a given set of covariates change significantly when other covariates are added into…</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://ntrs.nasa.gov/search.jsp?R=19880001942&hterms=breeze&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D20%26Ntt%3Dbreeze','NASA-TRS'); return false;" href="http://ntrs.nasa.gov/search.jsp?R=19880001942&hterms=breeze&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D20%26Ntt%3Dbreeze"><span id="translatedtitle">Short range forecasting of sea breeze generated thunderstorms at the Kennedy Space Center: A real-time experiment using a primitive equation <span class="hlt">mesoscale</span> numerical <span class="hlt">model</span></span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Lyons, Walter A.; Schuh, Jerome A.; Moon, Dennis; Pielke, Roger A.; Cotton, William; Arritt, Raymond</p> <p>1987-01-01</p> <p>The operational efficiency of using guidance from a <span class="hlt">mesoscale</span> numerical <span class="hlt">model</span> to improve sea breeze thunderstorm forecasts at and around the Shuttle landing strip was assessed. The Prognostic Three-Dimensional <span class="hlt">Mesoscale</span> (P3DM) <span class="hlt">model</span>, developed as a sea breeze <span class="hlt">model</span>, reveals a strong correlation between regions of <span class="hlt">mesoscale</span> convergence and the triggering of sea breeze convection thunderstorms. The P3DM was modified to generate stability parameters familiar to the operational forecaster. In addition to the <span class="hlt">mesoscale</span> fields of wind, vertical motion, moisture, temperature, a stability indicator, a combination of <span class="hlt">model</span>-predicted K and Lifted Indices and the maximum grid cell vertical motion, were proposed and tested. Results of blind tests indicate that a forecaster, provided with guidance derived from <span class="hlt">model</span> output, could improve local thunderstorm forecasts.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/19990109664','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19990109664"><span id="translatedtitle">Ocean Turbulence V: <span class="hlt">Mesoscale</span> <span class="hlt">Modeling</span> in Level Coordinates. The Effect of Random Nature of Density</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Canuto, V. M.; Dubovikov, M. S.</p> <p>1998-01-01</p> <p>The main result of this paper is the derivation of a new expression for the tracer subgrid term in level coordinates S(l) to be employed in O-GCM. The novel feature is the proper account of the random nature of the density field which strongly affects the transformation from isopycnal to level coordinates of the variables of interest, velocity and tracer fields, their correlation functions and ultimately the subgrid terms. In deriving our result we made use of measured properties of vertical ocean turbulence. The major new results are: 1) the new subgrid expression is different from that of the heuristic GM <span class="hlt">model</span>, 2) u++(tracer)=1/2u+(thickness), where u++ and u+ are the tracer and thickness bolus velocities. In previous <span class="hlt">models</span>, u++ = u+, 2) the subgrid for a tracer tau is not the same as that for the density rho even when one accounts for the obvious absence of a diffusion term in the latter. The difference stems from a new treatment of the stochastic nature of the density, 3) the <span class="hlt">mesoscale</span> diffusivity enters both locally and non-locally, as the integral over all z's from the bottom of the ocean to the level z.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015SPIE.9614E..0KH','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015SPIE.9614E..0KH"><span id="translatedtitle"><span class="hlt">Mesoscale</span> <span class="hlt">modeling</span> of optical turbulence (C2n) utilizing a novel physically-based parameterization</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>He, Ping; Basu, Sukanta</p> <p>2015-09-01</p> <p>In this paper, we propose a novel parameterization for optical turbulence (C2n) simulations in the atmosphere. In this approach, C2n is calculated from the output of atmospheric <span class="hlt">models</span> using a high-order turbulence closure scheme. An important feature of this parameterization is that, in the free atmosphere (i.e., above the boundary layer), it is consistent with a well-established C2n formulation by Tatarskii. Furthermore, it approaches a Monin-Obukhov similarity-based relationship in the surface layer. To test the performance of the proposed parameterization, we conduct <span class="hlt">mesoscale</span> <span class="hlt">modeling</span> and compare the simulated C2n values with those measured during two field campaigns over the Hawaii island. A popular regression-based approach proposed by Trinquet and Vernin (2007) is also used for comparison. The predicted C2n values, obtained from both the physically and statistically-based parameterizations, agree reasonably well with the observational data. However, in the presence of a large-scale atmospheric phenomenon (a breaking mountain wave), the physically-based parameterization outperforms the statistically-based one.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/biblio/5487152','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/biblio/5487152"><span id="translatedtitle"><span class="hlt">Modeling</span> <span class="hlt">mesoscale</span> diffusion and transport processes for releases within coastal zones during land/sea breezes</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Lyons, W.A.; Keen, C.S.; Schuh, J.A.</p> <p>1983-12-01</p> <p>This document discusses the impacts of coastal <span class="hlt">mesoscale</span> regimes (CMRs) upon the transport and diffusion of potential accidental radionuclide releases from a shoreline nuclear power plant. CMRs exhibit significant spatial (horizontal and vertical) and temporal variability. Case studies illustrate land breezes, sea/lake breeze inflows and return flows, thermal internal boundary layers, fumigation, plume trapping, coastal convergence zones, thunderstorms and snow squalls. The direct application of a conventional Gaussian straight-line dose assessment <span class="hlt">model</span>, initialized only by on-site tower data, can potentially produce highly misleading guidance as to plume impact locations. Since much is known concerning CMRs, there are many potential improvements to modularized dose assessment codes, such as by proper parameterization of TIBLs, forecasting the inland penetration of convergence zones, etc. A three-dimensional primitive equation prognostic <span class="hlt">model</span> showed excellent agreement with detailed lake breeze field measurements, giving indications that such codes can be used in both diagnostic and prognostic studies. The use of relatively inexpensive supplemental meteorological data especially from remote sensing systems (Doppler sodar, radar, lightning strike tracking) and computerized data bases should save significantly on software development costs. Better quality assurance of emergency response codes could include systems of flags providing personnel with confidence levels as to the applicability of a code being used during any given CMR.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/biblio/362024','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/biblio/362024"><span id="translatedtitle">Using a <span class="hlt">mesoscale</span> prognostic <span class="hlt">model</span> to construct a regional scale transport climatology. Part 2: Transport patterns</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Seely, S.L.; Dean, D.; Atchison, M.K.</p> <p>1998-12-31</p> <p>This study continues an investigation of the use of a prognostic <span class="hlt">mesoscale</span> meteorological <span class="hlt">model</span> to construct a regional scale climatology of pollution transport patterns around a site suffering from sparse data. In Part 1 of this study, the authors examined the accuracy of the RAMS <span class="hlt">model</span> in simulating the weather at an eastern Mediterranean site. For this part of the investigation, they examined the effect of varying types of weather data on the transport climatology results. Due to the large amounts of data generated by a lengthy weather simulation, they also attempted to reduce the amount of required simulation time by using samples of weather data. Five months (1990--1994) of NCAR/NCEP reanalysis gridded wind data are subjected to an S-mode eigenvector analysis to produce a set of 12 two-dimensional wind patterns over a 1000 km square region in the eastern Mediterranean. The five months are then clustered on the basis of similarity to these 12 patterns. A set of days is selected from each of the groups to form a sample. This set of days is considered representative of the wind patterns during the five months period. The authors will compare transport climatology results obtained using the full set of RAMS forecast data from Part 1 to those obtained using representative and random samples of the data. They also examine the effect of using sparse data on the transport climatology results.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/biblio/1257067','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/biblio/1257067"><span id="translatedtitle">Evaluation of Test Methods for Triaxially Braided Composites using a <span class="hlt">Meso-Scale</span> Finite Element <span class="hlt">Model</span></span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Zhang, Chao</p> <p>2015-10-01</p> <p>The characterization of triaxially braided composite is complicate due to the nonuniformity of deformation within the unit cell as well as the possibility of the freeedge effect related to the large size of the unit cell. Extensive experimental investigation has been conducted to develop more accurate test approaches in characterizing the actual mechanical properties of the material we are studying. In this work, a <span class="hlt">meso-scale</span> finite element <span class="hlt">model</span> is utilized to simulate two complex specimens: notched tensile specimen and tube tensile specimen, which are designed to avoid the free-edge effect and free-edge effect induced premature edge damage. The full field strain data is predicted numerically and compared with experimental data obtained by Digit Image Correlation. The numerically predicted tensile strength values are compared with experimentally measured results. The discrepancy between numerically predicted and experimentally measured data, the capability of different test approaches are analyzed and discussed. The presented numerical <span class="hlt">model</span> could serve as assistance to the evaluation of different test methods, and is especially useful in identifying potential local damage events.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016ThApC.124..461S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016ThApC.124..461S"><span id="translatedtitle">Seasonal evaluation of evapotranspiration fluxes from MODIS satellite and <span class="hlt">mesoscale</span> <span class="hlt">model</span> downscaled global reanalysis datasets</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Srivastava, Prashant K.; Han, Dawei; Islam, Tanvir; Petropoulos, George P.; Gupta, Manika; Dai, Qiang</p> <p>2016-04-01</p> <p>Reference evapotranspiration (ETo) is an important variable in hydrological <span class="hlt">modeling</span>, which is not always available, especially for ungauged catchments. Satellite data, such as those available from the MODerate Resolution Imaging Spectroradiometer (MODIS), and global datasets via the European Centre for Medium Range Weather Forecasts (ECMWF) reanalysis (ERA) interim and National Centers for Environmental Prediction (NCEP) reanalysis are important sources of information for ETo. This study explored the seasonal performances of MODIS (MOD16) and Weather Research and Forecasting (WRF) <span class="hlt">model</span> downscaled global reanalysis datasets, such as ERA interim and NCEP-derived ETo, against ground-based datasets. Overall, on the basis of the statistical metrics computed, ETo derived from ERA interim and MODIS were more accurate in comparison to the estimates from NCEP for all the seasons. The pooled datasets also revealed a similar performance to the seasonal assessment with higher agreement for the ERA interim (r = 0.96, RMSE = 2.76 mm/8 days; bias = 0.24 mm/8 days), followed by MODIS (r = 0.95, RMSE = 7.66 mm/8 days; bias = -7.17 mm/8 days) and NCEP (r = 0.76, RMSE = 11.81 mm/8 days; bias = -10.20 mm/8 days). The only limitation with downscaling ERA interim reanalysis datasets using WRF is that it is time-consuming in contrast to the readily available MODIS operational product for use in <span class="hlt">mesoscale</span> studies and practical applications.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/17301012','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/17301012"><span id="translatedtitle">Making good choices with variable information: a stochastic <span class="hlt">model</span> for <span class="hlt">nest</span>-site selection by honeybees.</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Perdriau, Benjamin S; Myerscough, Mary R</p> <p>2007-04-22</p> <p>A density-dependent Markov process <span class="hlt">model</span> is constructed for information transfer among scouts during <span class="hlt">nest</span>-site selection by honeybees (Apis mellifera). The effects of site quality, competition between sites and delays in site discovery are investigated. The <span class="hlt">model</span> predicts that bees choose the better of two sites more reliably when both sites are of low quality than when both sites are of high quality and that delay in finding a second site has most effect on the final choice when both sites are of high quality. The <span class="hlt">model</span> suggests that stochastic effects in honeybee <span class="hlt">nest</span>-site selection confer no advantage on the swarm. PMID:17301012</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/servlets/purl/471412','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/servlets/purl/471412"><span id="translatedtitle">The effect of urban canopy parameterizations on <span class="hlt">mesoscale</span> meteorological <span class="hlt">model</span> simulations in the Paso del Norte area</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Brown, M.J.; Williams, M.D.</p> <p>1997-04-01</p> <p>Since <span class="hlt">mesoscale</span> numerical <span class="hlt">models</span> do not have the spatial resolution to directly simulate the fluid dynamics and thermodynamics in and around urban structures, urban canopy parameterizations are sometimes used to approximate the drag, heating, and enhanced turbulent kinetic energy (tke) produced by the sub-grid scale urban elements. In this paper, we investigate the effect of the urban canopy parameterizations used in the HOTMAC <span class="hlt">mesoscale</span> meteorological <span class="hlt">model</span> by turning the parameterizations on and off. The <span class="hlt">model</span> simulations were performed in the Paso del Norte region, which includes the cities of El Paso and Ciudad Juarez, the Franklin and Sierra Juarez mountains, and the Rio Grande. The metropolitan area is surrounded by relatively barren scrubland and is intersected by strips of vegetation along the Rio Grande. Results indicate that the urban canopy parameterizations do affect the <span class="hlt">mesoscale</span> flow field, reducing the magnitude of wind speed and changing the magnitude of the sensible heat flux and tke in the metropolitan area. A nighttime heat island and a daytime cool island exist when urban canopy parameters are turned on, but associated recirculation flows are not readily apparent. <span class="hlt">Model</span>-computed solar, net, and longwave radiation values look reasonable, agreeing for the most part with published measurements.</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_12");'>12</a></li> <li><a href="#" onclick='return showDiv("page_13");'>13</a></li> <li class="active"><span>14</span></li> <li><a href="#" onclick='return showDiv("page_15");'>15</a></li> <li><a href="#" onclick='return showDiv("page_16");'>16</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_14 --> <div id="page_15" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_13");'>13</a></li> <li><a href="#" onclick='return showDiv("page_14");'>14</a></li> <li class="active"><span>15</span></li> <li><a href="#" onclick='return showDiv("page_16");'>16</a></li> <li><a href="#" onclick='return showDiv("page_17");'>17</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="281"> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/26712602','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/26712602"><span id="translatedtitle">A <span class="hlt">meso-scale</span> layer-specific structural constitutive <span class="hlt">model</span> of the mitral heart valve leaflets.</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Zhang, Will; Ayoub, Salma; Liao, Jun; Sacks, Michael S</p> <p>2016-03-01</p> <p>Fundamental to developing a deeper understanding of pathophysiological remodeling in mitral valve (MV) disease is the development of an accurate tissue-level constitutive <span class="hlt">model</span>. In the present work, we developed a novel <span class="hlt">meso-scale</span> (i.e. at the level of the fiber, 10-100μm in length scale) structural constitutive <span class="hlt">model</span> (MSSCM) for MV leaflet tissues. Due to its four-layer structure, we focused on the contributions from the distinct collagen and elastin fiber networks within each tissue layer. Requisite collagen and elastin fibrous structural information for each layer were quantified using second harmonic generation microscopy and conventional histology. A comprehensive mechanical dataset was also used to guide <span class="hlt">model</span> formulation and parameter estimation. Furthermore, novel to tissue-level structural constitutive <span class="hlt">modeling</span> approaches, we allowed the collagen fiber recruitment function to vary with orientation. Results indicated that the MSSCM predicted a surprisingly consistent mean effective collagen fiber modulus of 162.72MPa, and demonstrated excellent predictive capability for extra-physiological loading regimes. There were also anterior-posterior leaflet-specific differences, such as tighter collagen and elastin fiber orientation distributions (ODF) in the anterior leaflet, and a thicker and stiffer atrialis in the posterior leaflet. While a degree of angular variance was observed, the tight valvular tissue ODF also left little room for any physically meaningful angular variance in fiber mechanical responses. Finally, a novel fibril-level (0.1-1μm) validation approach was used to compare the predicted collagen fiber/fibril mechanical behavior with extant MV small angle X-ray scattering data. Results demonstrated excellent agreement, indicating that the MSSCM fully captures the tissue-level function. Future utilization of the MSSCM in computational <span class="hlt">models</span> of the MV will aid in producing highly accurate simulations in non-physiological loading states that can</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://cfpub.epa.gov/si/si_public_record_report.cfm?dirEntryId=30916&keyword=momentum&actType=&TIMSType=+&TIMSSubTypeID=&DEID=&epaNumber=&ntisID=&archiveStatus=Both&ombCat=Any&dateBeginCreated=&dateEndCreated=&dateBeginPublishedPresented=&dateEndPublishedPresented=&dateBeginUpdated=&dateEndUpdated=&dateBeginCompleted=&dateEndCompleted=&personID=&role=Any&journalID=&publisherID=&sortBy=revisionDate&count=50&CFID=64003652&CFTOKEN=94427683','EPA-EIMS'); return false;" href="http://cfpub.epa.gov/si/si_public_record_report.cfm?dirEntryId=30916&keyword=momentum&actType=&TIMSType=+&TIMSSubTypeID=&DEID=&epaNumber=&ntisID=&archiveStatus=Both&ombCat=Any&dateBeginCreated=&dateEndCreated=&dateBeginPublishedPresented=&dateEndPublishedPresented=&dateBeginUpdated=&dateEndUpdated=&dateBeginCompleted=&dateEndCompleted=&personID=&role=Any&journalID=&publisherID=&sortBy=revisionDate&count=50&CFID=64003652&CFTOKEN=94427683"><span id="translatedtitle">IMPLEMENTATION AND EXPERIMENTATION ON AN ADVANCED LAND-SURFACE/PBL <span class="hlt">MODEL</span> IN THE PENN STATE/NCAR <span class="hlt">MESOSCALE</span> <span class="hlt">MODEL</span> (MM4)</span></a></p> <p><a target="_blank" href="http://oaspub.epa.gov/eims/query.page">EPA Science Inventory</a></p> <p></p> <p></p> <p>A more advanced surface/PBL <span class="hlt">model</span> is implemented in the Penn State/NCAR <span class="hlt">Mesoscale</span> <span class="hlt">Model</span> Version 4 (MM4) which is utilized to provide meteorological data to the Regional Acid Deposition <span class="hlt">Model</span> (RADM). he diurnal evolution of the Planetary Boundary Layer (PBL) and its dynamic charac...</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2011Geomo.130..230D','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2011Geomo.130..230D"><span id="translatedtitle"><span class="hlt">Meso-scale</span> <span class="hlt">modelling</span> of aeolian sediment input to coastal dunes</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Delgado-Fernandez, Irene</p> <p>2011-07-01</p> <p>The collection of a time series coupling hourly wind data (speed and direction) with sand transport over months has provided new insights into the dynamics of transport events that input sediment to the foredune at Greenwich Dunes, Prince Edward Island National Park, Canada. This paper summarises the key aspects of aeolian sediment movement for a period of 9 months and presents a <span class="hlt">modelling</span> approach for resolving aeolian transport to coastal dunes at the <span class="hlt">meso-scale</span>. The main hypothesis of the <span class="hlt">modelling</span> approach is that a small number of key factors control both the occurrence and the magnitude of transport events. Thresholds associated with these factors may be used to filter the time series and isolate potential transport periods over the year. The impacts of nearshore processes are included in the approach as part of the dynamics of coastal dunes, as are supply-limiting factors and trade-offs between fetch distances, angle of wind approach, and beach dimensions. A simple analytical procedure, based on previously published equations, is carried out to assess the general viability of the conceptual approach. Results show that the incorporation of moisture and fetch effects in the calculation of transport for isolated potential transport periods result in improved predictions of sediment input to the dune. Net changes, measured with three different techniques, suggest that survey data with coarse temporal resolution underestimates the amount of sand input to the dune, because sediment is often removed from the embryo dune and foredune by other processes such as wave scarping. Predictions obtained by the proposed <span class="hlt">modelling</span> approach are of the same order of magnitude as measured deposition and much less than predicted by <span class="hlt">models</span> based solely on wind speed and direction. Areas for improvement and alternative <span class="hlt">modelling</span> approaches, such as probabilistic approaches similar to weather forecasting, are covered in the discussion.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://ntrs.nasa.gov/search.jsp?R=20010021327&hterms=pollution+skin&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D80%26Ntt%3Dpollution%2Bskin','NASA-TRS'); return false;" href="http://ntrs.nasa.gov/search.jsp?R=20010021327&hterms=pollution+skin&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D80%26Ntt%3Dpollution%2Bskin"><span id="translatedtitle">Use of Geostationary Satellite Data to Force Land Surface Schemes within Atmospheric <span class="hlt">Mesoscale</span> <span class="hlt">Models</span></span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Lapenta, William M.; Suggs, Ron; McNider, Richard T.; Jedlovec, Gary; Dembek, Scott R.; Goodman, H. Michael (Technical Monitor)</p> <p>2000-01-01</p> <p>A technique has been developed for assimilating GOES-derived skin temperature tendencies and insolation into the surface energy budget equation of a <span class="hlt">mesoscale</span> <span class="hlt">model</span> so that the simulated rate of temperature change closely agrees with the satellite observations. A critical assumption of the technique is that the availability of moisture (either from the soil or vegetation) is the least known term in the <span class="hlt">model</span>'s surface energy budget. Therefore, the simulated latent heat flux, which is a function of surface moisture availability, is adjusted based upon differences between the <span class="hlt">modeled</span> and satellite-observed skin temperature tendencies. An advantage of this technique is that satellite temperature tendencies are assimilated in an energetically consistent manner that avoids energy imbalances and surface stability problems that arise from direct assimilation of surface shelter temperatures. The fact that the rate of change of the satellite skin temperature is used rather than the absolute temperature means that sensor calibration is not as critical. The technique has been employed on a semi-operational basis at the GHCC within the PSU/NCAR MM5. Assimilation has been performed on a grid centered over the Southeastern US since November 1998. Results from the past year show that assimilation of the satellite data reduces both the bias and RMSE for simulations of surface air temperature and relative humidity. These findings are based on comparison of assimilation runs with a control using the simple 5-layer soil <span class="hlt">model</span> available in MM5. A significant development in the past several months was the inclusion of the detailed Oregon State University land surface <span class="hlt">model</span> (OSU/LSM) as an option within MM5. One of our working hypotheses has been that the assimilation technique, although simple, may provide better short-term forecasts than a detailed LSM that requires significant number initialized parameters. Preliminary results indicate that the assimilation out performs the OSU</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://ntrs.nasa.gov/search.jsp?R=20030054358&hterms=meteorology&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D60%26Ntt%3Dmeteorology','NASA-TRS'); return false;" href="http://ntrs.nasa.gov/search.jsp?R=20030054358&hterms=meteorology&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D60%26Ntt%3Dmeteorology"><span id="translatedtitle">Meteorology, Macrophysics, Microphysics, Microwaves, and <span class="hlt">Mesoscale</span> <span class="hlt">Modeling</span> of Mediterranean Mountain Storms: The M8 Laboratory</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Starr, David O. (Technical Monitor); Smith, Eric A.</p> <p>2002-01-01</p> <p>Comprehensive understanding of the microphysical nature of Mediterranean storms can be accomplished by a combination of in situ meteorological data analysis and radar-passive microwave data analysis, effectively integrated with numerical <span class="hlt">modeling</span> studies at various scales, from synoptic scale down through the <span class="hlt">mesoscale</span>, the cloud macrophysical scale, and ultimately the cloud microphysical scale. The microphysical properties of and their controls on severe storms are intrinsically related to meteorological processes under which storms have evolved, processes which eventually select and control the dominant microphysical properties themselves. This involves intense convective development, stratiform decay, orographic lifting, and sloped frontal lifting processes, as well as the associated vertical motions and thermodynamical instabilities governing physical processes that affect details of the size distributions and fall rates of the various types of hydrometeors found within the storm environment. Insofar as hazardous Mediterranean storms, highlighted in this study by three mountain storms producing damaging floods in northern Italy between 1992 and 2000, developing a comprehensive microphysical interpretation requires an understanding of the multiple phases of storm evolution and the heterogeneous nature of precipitation fields within a storm domain. This involves convective development, stratiform transition and decay, orographic lifting, and sloped frontal lifting processes. This also involves vertical motions and thermodynamical instabilities governing physical processes that determine details of the liquid/ice water contents, size disi:ributions, and fall rates of the various modes of hydrometeors found within hazardous storm environments.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/26602508','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/26602508"><span id="translatedtitle">Electrostatic Interactions in Dissipative Particle Dynamics: Toward a <span class="hlt">Mesoscale</span> <span class="hlt">Modeling</span> of the Polyelectrolyte Brushes.</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Ibergay, Cyrille; Malfreyt, Patrice; Tildesley, Dominic J</p> <p>2009-12-01</p> <p>We report mesoscopic simulations of bulk electrolytes and polyelectrolyte brushes using the dissipative particle dynamics (DPD) method. The calculation of the electrostatic interactions is carried out using both the Ewald summation method and the particle-particle particle-mesh technique with charges distributed over the particles. The local components of the pressure tensor are calculated using the Irving and Kirkwood, and the method of planes and mechanical equilibrium is demonstrated. The profiles of the normal component of the pressure tensor are shown to be similar for both the Ewald and particle-particle particle-mesh methods for a single polyelectrolyte brush. We show that the PPPM method with the MOP technique is the appropriate choice for simulations of this type. The <span class="hlt">mesoscale</span> <span class="hlt">modeling</span> of a strongly stretched polylectrolyte brush formed by strong charged polymer chains at a high grafting density shows that the polyelectrolyte follows the nonlinear osmotic regime, as expected from the calculation of the Gouy-Chapman length and the dimensionless Manning ratio. PMID:26602508</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/20140013352','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20140013352"><span id="translatedtitle">Genesis of Hurricane Sandy (2012) Simulated with a Global <span class="hlt">Mesoscale</span> <span class="hlt">Model</span></span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Shen, Bo-Wen; DeMaria, Mark; Li, J.-L. F.; Cheung, S.</p> <p>2013-01-01</p> <p>In this study, we investigate the formation predictability of Hurricane Sandy (2012) with a global <span class="hlt">mesoscale</span> <span class="hlt">model</span>. We first present five track and intensity forecasts of Sandy initialized at 00Z 22-26 October 2012, realistically producing its movement with a northwestward turn prior to its landfall. We then show that three experiments initialized at 00Z 16-18 October captured the genesis of Sandy with a lead time of up to 6 days and simulated reasonable evolution of Sandy's track and intensity in the next 2 day period of 18Z 21-23 October. Results suggest that the extended lead time of formation prediction is achieved by realistic simulations of multiscale processes, including (1) the interaction between an easterly wave and a low-level westerly wind belt (WWB) and (2) the appearance of the upper-level trough at 200 hPa to Sandy's northwest. The low-level WWB and upper-level trough are likely associated with a Madden-Julian Oscillation.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2013OcDyn..63..793G','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2013OcDyn..63..793G"><span id="translatedtitle">A case study of the <span class="hlt">mesoscale</span> dynamics in the North-Western Mediterranean Sea: a combined data-<span class="hlt">model</span> approach</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Guihou, Karen; Marmain, Julien; Ourmières, Yann; Molcard, Anne; Zakardjian, Bruno; Forget, Philippe</p> <p>2013-07-01</p> <p>The Northern current is the main circulation feature of the North-Western Mediterranean Sea. While the large-scale to <span class="hlt">mesoscale</span> variability of the northern current (NC) is well known and widely documented for the Ligurian region, off Nice or along the Gulf of Lions shelf, few is known about the current instabilities and its associated <span class="hlt">mesoscale</span> dynamics in the intermediate area, off Toulon. Here, we took advantage of an oceanographic cruise of opportunity, the start of a HF radar monitoring programme in the Toulon area and the availability of regular satellite sea surface temperature and chlorophyll a data, to evaluate the realism of a NEMO-based regional high-resolution <span class="hlt">model</span> and the added value brought by HF radar. The combined analysis of a 1/64° configuration, named GLAZUR64, and of all data sets revealed the occurrence of an anticyclonic coastal trapped eddy, generated inside a NC meander and passing the Toulon area during the field campaign. We show that this anticyclonic eddy is advected downstream along the French Riviera up to the study region and disturbs the Northern current flow. This study aims to show the importance of combining observations and <span class="hlt">modelling</span> when dealing with <span class="hlt">mesoscale</span> processes, as well as the importance of high-resolution <span class="hlt">modelling</span>.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2013PhDT........29Y&link_type=ABSTRACT','NASAADS'); return false;" href="http://adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2013PhDT........29Y&link_type=ABSTRACT"><span id="translatedtitle">Investigation into a displacement bias in numerical weather prediction <span class="hlt">models</span>' forecasts of <span class="hlt">mesoscale</span> convective systems</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Yost, Charles</p> <p></p> <p>Although often hard to correctly forecast, <span class="hlt">mesoscale</span> convective systems (MCSs) are responsible for a majority of warm-season, localized extreme rain events. This study investigates displacement errors often observed by forecasters and researchers in the Global Forecast System (GFS) and the North American <span class="hlt">Mesoscale</span> (NAM) <span class="hlt">models</span>, in addition to the European Centre for Medium Range Weather Forecasts (ECMWF) and the 4-km convection allowing NSSL-WRF <span class="hlt">models</span>. Using archived radar data and Stage IV precipitation data from April to August of 2009 to 2011, MCSs were recorded and sorted into unique six-hour intervals. The locations of these MCSs were compared to the associated predicted precipitation field in all <span class="hlt">models</span> using the Method for Object-Based Diagnostic Evaluation (MODE) tool, produced by the Developmental Testbed Center and verified through manual analysis. A northward bias exists in the location of the forecasts in all lead times of the GFS, NAM, and ECMWF <span class="hlt">models</span>. The MODE tool found that 74%, 68%, and 65% of the forecasts were too far to the north of the observed rainfall in the GFS, NAM and ECMWF <span class="hlt">models</span> respectively. The higher-resolution NSSL-WRF <span class="hlt">model</span> produced a near neutral location forecast error with 52% of the cases too far to the south. The GFS <span class="hlt">model</span> consistently moved the MCSs too quickly with 65% of the cases located to the east of the observed MCS. The mean forecast displacement error from the GFS and NAM were on average 266 km and 249 km, respectively, while the ECMWF and NSSL-WRF produced a much lower average of 179 km and 158 km. A case study of the Dubuque, IA MCS on 28 July 2011 was analyzed to identify the root cause of this bias. This MCS shattered several rainfall records and required over 50 people to be rescued from mobile home parks from around the area. This devastating MCS, which was a classic Training Line/Adjoining Stratiform archetype, had numerous northward-biased forecasts from all <span class="hlt">models</span>, which are examined here. As common with</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://eric.ed.gov/?q=analysis+AND+nominal&pg=2&id=EJ1083301','ERIC'); return false;" href="http://eric.ed.gov/?q=analysis+AND+nominal&pg=2&id=EJ1083301"><span id="translatedtitle">An Odds Ratio Approach for Detecting DDF under the <span class="hlt">Nested</span> Logit <span class="hlt">Modeling</span> Framework</span></a></p> <p><a target="_blank" href="http://www.eric.ed.gov/ERICWebPortal/search/extended.jsp?_pageLabel=advanced">ERIC Educational Resources Information Center</a></p> <p>Terzi, Ragip; Suh, Youngsuk</p> <p>2015-01-01</p> <p>An odds ratio approach (ORA) under the framework of a <span class="hlt">nested</span> logit <span class="hlt">model</span> was proposed for evaluating differential distractor functioning (DDF) in multiple-choice items and was compared with an existing ORA developed under the nominal response <span class="hlt">model</span>. The performances of the two ORAs for detecting DDF were investigated through an extensive…</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://eric.ed.gov/?q=bolt&pg=2&id=EJ959349','ERIC'); return false;" href="http://eric.ed.gov/?q=bolt&pg=2&id=EJ959349"><span id="translatedtitle">Application of a Multidimensional <span class="hlt">Nested</span> Logit <span class="hlt">Model</span> to Multiple-Choice Test Items</span></a></p> <p><a target="_blank" href="http://www.eric.ed.gov/ERICWebPortal/search/extended.jsp?_pageLabel=advanced">ERIC Educational Resources Information Center</a></p> <p>Bolt, Daniel M.; Wollack, James A.; Suh, Youngsuk</p> <p>2012-01-01</p> <p><span class="hlt">Nested</span> logit <span class="hlt">models</span> have been presented as an alternative to multinomial logistic <span class="hlt">models</span> for multiple-choice test items (Suh and Bolt in "Psychometrika" 75:454-473, 2010) and possess a mathematical structure that naturally lends itself to evaluating the incremental information provided by attending to distractor selection in scoring. One potential…</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://ntrs.nasa.gov/search.jsp?R=20040016359&hterms=seasons&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D50%26Ntt%3Dseasons','NASA-TRS'); return false;" href="http://ntrs.nasa.gov/search.jsp?R=20040016359&hterms=seasons&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D50%26Ntt%3Dseasons"><span id="translatedtitle">Diabatic Initialization of <span class="hlt">Mesoscale</span> <span class="hlt">Models</span> in the Southeastern United States: Can 0 to 12h Warm Season QPF be Improved?</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Lapenta, William M.; Bradshaw, Tom; Burks, Jason; Darden, Chris; Dembek, Scott</p> <p>2003-01-01</p> <p>It is well known that numerical warm season quantitative precipitation forecasts lack significant skill for numerous reasons. Some are related to the <span class="hlt">model</span>--it may lack physical processes required to realistically simulate convection or the numerical algorithms and dynamics employed may not be adequate. Others are related to initialization-<span class="hlt">mesoscale</span> features play an important role in convective initialization and atmospheric observation systems are incapable of properly depicting the three-dimensional stability structure at the <span class="hlt">mesoscale</span>. The purpose of this study is to determine if a <span class="hlt">mesoscale</span> <span class="hlt">model</span> initialized with a diabatic initialization scheme can improve short-term (0 to 12h) warm season quantitative precipitation forecasts in the Southeastern United States. The Local Analysis and Prediction System (LAPS) developed at the Forecast System Laboratory is used to diabatically initialize the Pennsylvania State University/National center for Atmospheric Research (PSUNCAR) <span class="hlt">Mesoscale</span> <span class="hlt">Model</span> version 5 (MM5). The SPORT Center runs LAPS operationally on an hourly cycle to produce analyses on a 15 km covering the eastern 2/3 of the United States. The 20 km National Centers for Environmental Prediction (NCEP) Rapid Update Cycle analyses are used for the background fields. Standard observational data are acquired from MADIS with GOES/CRAFT Nexrad data acquired from in-house feeds. The MM5 is configured on a 140 x 140 12 km grid centered on Huntsville Alabama. Preliminary results indicate that MM5 runs initialized with LAPS produce improved 6 and 12h QPF threat scores compared with those initialized with the NCEP RUC.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2009EGUGA..1112915H','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2009EGUGA..1112915H"><span id="translatedtitle">Linear and nonlinear response to parameter variations in a <span class="hlt">mesoscale</span> <span class="hlt">model</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Hacker, J.; Snyder, C.</p> <p>2009-04-01</p> <p>It is widely recognized that ensemble prediction system (EPS) skill can improve when considering <span class="hlt">model</span> error in the system design. Typical approaches include varying physical parameterization schemes or entire <span class="hlt">modeling</span> systems within an EPS, and including stochastic terms in the dynamical equations. But perhaps the simplest approach to accounting for uncertainty in a <span class="hlt">model</span> is to perturb inherently uncertain parameters within sub-grid parameterization schemes. Although it almost certainly cannot introduce all the modes of variability produced by other methods, its simplicity alone suggests that its effect on prediction skill and variability deserves quantitative scrutiny. In this work we seek to understand how perturbations to uncertain parameters manifest in a <span class="hlt">mesoscale</span> <span class="hlt">model</span>, and evaluate the potential for use in EPSs or data assimilation systems that can exploit ensemble covariances and linear or nonlinear responses. A set of four parameters are varied, corresponding to one each in cumulus, cloud microphysics, boundary-layer turbulence, and radiation schemes within the Weather Research and Forecast (WRF) <span class="hlt">mesoscale</span> numerical weather prediction <span class="hlt">model</span>. Parameters are drawn only once from distributions intended to capture the uncertainty estimated by experts and reported in the literature. Each set of parameters is drawn with a Latin Hypercube Sampling technique that ensures the parameter sets are independent and fill the four-dimensional space spanned by the parameters. The parameter sets are then fixed and an ensemble of 10 members uses them for approximately 30 ensemble forecasts that are also subject to initial-condition, lateral boundary-condition and land-surface uncertainty. We show that the parameters and state variables have clear linear relationship in certain regions and at certain times; elsewhere there may be either little dependence of the state on the parameter, or a nonlinear dependence. Linear response and ensemble sensitivity are quantified with</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/26113190','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/26113190"><span id="translatedtitle">A simple, physiologically-based <span class="hlt">model</span> of sea turtle remigration intervals and <span class="hlt">nesting</span> population dynamics: Effects of temperature.</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Neeman, Noga; Spotila, James R; O'Connor, Michael P</p> <p>2015-09-01</p> <p>Variation in the yearly number of sea turtles <span class="hlt">nesting</span> at rookeries can interfere with population estimates and obscure real population dynamics. Previous theoretical <span class="hlt">models</span> suggested that this variation in <span class="hlt">nesting</span> numbers may be driven by changes in resources at the foraging grounds. We developed a physiologically-based <span class="hlt">model</span> that uses temperatures at foraging sites to predict foraging conditions, resource accumulation, remigration probabilities, and, ultimately, <span class="hlt">nesting</span> numbers for a stable population of sea turtles. We used this <span class="hlt">model</span> to explore several scenarios of temperature variation at the foraging grounds, including one-year perturbations and cyclical temperature oscillations. We found that thermally driven resource variation can indeed synchronize <span class="hlt">nesting</span> in groups of turtles, creating cohorts, but that these cohorts tend to break down over 5-10 years unless regenerated by environmental conditions. Cohorts were broken down faster at lower temperatures. One-year perturbations of low temperature had a synchronizing effect on <span class="hlt">nesting</span> the following year, while high temperature perturbations tended to delay <span class="hlt">nesting</span> in a less synchronized way. Cyclical temperatures lead to cyclical responses both in <span class="hlt">nesting</span> numbers and remigration intervals, with the amplitude and lag of the response depending on the duration of the cycle. Overall, <span class="hlt">model</span> behavior is consistent with observations at <span class="hlt">nesting</span> beaches. Future work should focus on refining the <span class="hlt">model</span> to fit particular <span class="hlt">nesting</span> populations and testing further whether or not it may be used to predict observed <span class="hlt">nesting</span> numbers and remigration intervals. PMID:26113190</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2007AGUFM.A43C1429B','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2007AGUFM.A43C1429B"><span id="translatedtitle">Sahelian dust lifting in the inter-tropical discontinuity region: Lidar observations and <span class="hlt">mesoscale</span> <span class="hlt">modelling</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Bou Karam, D.; Flamant, C.; Tulet, P.; Chaboureau, J.; Dabas, A.; Chong, M.; Reitebuch, O.</p> <p>2007-12-01</p> <p>Airbone lidar observations acquired with the LEANDRE 2 system during 3 flights of the SAFIRE Falcon 20 in the framework of the AMMA Special Observing Period (SOP) 2a1 (July 2006) over western Niger, revealed the existence of desert dust uptakes in the region of the inter-tropical discontinuity (ITD) in the morning hours. Complementary observations provided by dropsondes released from the same platform as well as airborne wind measurements made from another platform (the DLR Falcon 20, flying in coordination with the SAFIRE Falcon 20) evidenced that the lifting was associated with the leading edge of the monsoon low level jet, and to be transported southward by the harmattan, above the monsoon layer. A 10-day numerical simulation, using the <span class="hlt">mesoscale</span> <span class="hlt">model</span> Meso-NH (including the dust emission box Dust Entrainment And Deposition <span class="hlt">model</span>), was conducted to assess the representativity of the observed phenomenon as well as the mechanisms associated with the Sahelian dust emissions. The Meso-NH simulation (initialized by and nudged with ECMWF analyses) was carried out on a 2000 km x 2000 km domain (20-km horizontal resolution) centered at 20°N and 7°E, that included the Falcons flight track, as well as numerous AMMA-related ground-based measurement sites (Tamanrasset, Agadez, Niamey/Banizoumbou, etc..) for validation purposes. In the simulation, large dust uptakes associated with the leading edge of the monsoon flow, with a dust concentration reaching 2000μg/m3, and to be transported southward by the harmattan, above the monsoon layer, were well reproduced. On the other hand, the simulation suggested the existence of dust emissions associated with the harmattan flow which were not observed by airborne lidar measurements. The reason for the discrepancy between the <span class="hlt">model</span> results and the lidar observations is investigated.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://cfpub.epa.gov/si/si_public_record_report.cfm?dirEntryId=46732&keyword=ive&actType=&TIMSType=+&TIMSSubTypeID=&DEID=&epaNumber=&ntisID=&archiveStatus=Both&ombCat=Any&dateBeginCreated=&dateEndCreated=&dateBeginPublishedPresented=&dateEndPublishedPresented=&dateBeginUpdated=&dateEndUpdated=&dateBeginCompleted=&dateEndCompleted=&personID=&role=Any&journalID=&publisherID=&sortBy=revisionDate&count=50&CFID=67303169&CFTOKEN=15702614','EPA-EIMS'); return false;" href="http://cfpub.epa.gov/si/si_public_record_report.cfm?dirEntryId=46732&keyword=ive&actType=&TIMSType=+&TIMSSubTypeID=&DEID=&epaNumber=&ntisID=&archiveStatus=Both&ombCat=Any&dateBeginCreated=&dateEndCreated=&dateBeginPublishedPresented=&dateEndPublishedPresented=&dateBeginUpdated=&dateEndUpdated=&dateBeginCompleted=&dateEndCompleted=&personID=&role=Any&journalID=&publisherID=&sortBy=revisionDate&count=50&CFID=67303169&CFTOKEN=15702614"><span id="translatedtitle"><span class="hlt">NESTED</span> GRID <span class="hlt">MODELING</span> APPROACH FOR ASSESSING URBAN OZONE AIR QUALITY</span></a></p> <p><a target="_blank" href="http://oaspub.epa.gov/eims/query.page">EPA Science Inventory</a></p> <p></p> <p></p> <p>This paper describes an effort to interface the <span class="hlt">modeled</span> concentrations and other outputs of the Regional Oxidant <span class="hlt">Model</span> (ROM) as an alternative set of input files to apply in Urban Airshed <span class="hlt">Model</span> (UAM) simulations. ive different days exhibiting high ozone concentrations during the ...</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2002iaf..confE..95S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2002iaf..confE..95S"><span id="translatedtitle">Using Landsat-Derived Land Cover, Restructured Vegetation, and Atmospheric <span class="hlt">Mesoscale</span> <span class="hlt">Modeling</span> in Environmental and Global Change Research</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Steyaert, L. T.; Pielke, R. A., Sr.</p> <p></p> <p>The USGS and Colorado State University (CSU) have used historical land cover data sets in CSU's regional atmospheric <span class="hlt">modeling</span> system (RAMS) to investigate the potential effects of human-induced land cover change on land surface processes and regional climate variability for two study areas: South Florida and the eastern United States. Over the past 200 years, these areas have experienced significant land cover change including clearing of native forests, agricultural expansion, farm abandonment, reforestation, landscape fragmentation, growing urbanization, and altered wetlands. Understanding the potential effects of past and future land use changes is of interest to the environmental <span class="hlt">modeling</span>, land resource management, and global change science communities. This paper summarizes the land cover data analysis, <span class="hlt">mesoscale</span> <span class="hlt">modeling</span> considerations, and potential benefits from using Landsat-derived products. Historical data sets were developed for the <span class="hlt">modeling</span> simulations in each study area. The primary source of current land cover and land use data was the USGS 30-m National Land Cover Data (NLCD) which was developed for the conterminous United States from 1992/93 Landsat TM scenes. The NLCD data were selectively merged with the USGS and University of Florida 30-m GAP land cover product that was developed from 1992-94 Landsat TM scenes and extensive field data analysis. The resulting 100-m aggregated data set permitted a more complete representation of Florida's complex vegetation and wetlands conditions for the <span class="hlt">modeling</span>. The pre-disturbance late-1800's natural vegetation scenario for the Florida simulations was based on an analysis of various historical maps of the Everglades, adjustments to these maps based on USGS paleo-vegetation analysis from sedimentary core samples, ancillary information, and analysis of Kuchler's potential natural vegetation data. Historical reconstructed vegetation scenarios for the 1850 and 1920 timeframes in the eastern United States were</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014EGUGA..16.3810S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014EGUGA..16.3810S"><span id="translatedtitle">An open-source distributed <span class="hlt">mesoscale</span> hydrologic <span class="hlt">model</span> (mHM)</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Samaniego, Luis; Kumar, Rohini; Zink, Matthias; Thober, Stephan; Mai, Juliane; Cuntz, Matthias; Schäfer, David; Schrön, Martin; Musuuza, Jude; Prykhodko, Vladyslav; Dalmasso, Giovanni; Attinger, Sabine; Spieler, Diana; Rakovec, Oldrich; Craven, John; Langenberg, Ben</p> <p>2014-05-01</p> <p>The <span class="hlt">mesoscale</span> hydrological <span class="hlt">model</span> (mHM) is based on numerical approximations of dominant hydrological processes that have been tested in various hydrological <span class="hlt">models</span> such as: HBV and VIC. In general, mHM simulates the following processes: canopy interception, snow accumulation and melting, soil moisture dynamics (n-horizons), infiltration and surface runoff, evapotranspiration, subsurface storage and discharge generation, deep percolation and baseflow, and discharge attenuation and flood routing. The main characteristic of mHM is the treatment of the sub-grid variability of input variables and <span class="hlt">model</span> parameters which clearly distinguishes this <span class="hlt">model</span> from existing precipitation-runoff <span class="hlt">models</span> or land surface <span class="hlt">models</span>. It uses a Multiscale Parameter Regionalization (MPR) to account for the sub-grid variability and to avoid continuous re-calibration. Effective <span class="hlt">model</span> parameters are location and time dependent (e.g., soil porosity). They are estimated through upscaling operators that link sub-grid morphologic information (e.g., soil texture) with global transfer-function parameters, which, in turn, are found through multi-basin optimization. Global parameters estimated with the MPR technique are quasi-scale invariant and guarantee flux-matching across scales. mHM is an open source code, written in Fortran 2003 (standard), fully modular, with high computational efficiency, and parallelized. It is portable to multiple platforms (Linux, OS X, Windows) and includes a number of algorithms for sensitivity analysis, analysis of parameter uncertainty (MCMC), and optimization (DDS, SA, SCE). All simulated state variables and outputs can be stored as netCDF files for further analysis and visualization. mHM has been evaluated in all major river basins in Germany and over 80 US and 250 European river basins. The <span class="hlt">model</span> efficiency (NSE) during validation at proxy locations is on average greater than 0.6. During last years, mHM had been used for number of hydrologic applications such as</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/servlets/purl/945797','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/servlets/purl/945797"><span id="translatedtitle"><span class="hlt">Meso-Scale</span> <span class="hlt">Modeling</span> of Spall in a Heterogeneous Two-Phase Material</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Springer, H K</p> <p>2008-06-26</p> <p>The influence of the heterogeneous second-phase particle structure and applied loading conditions on the ductile spall response of a <span class="hlt">model</span> two-phase material was investigated. Quantitative metallography, three-dimensional (3D) <span class="hlt">meso-scale</span> simulations (MSS), and small-scale spall experiments provided the foundation for this study. Nodular ductile iron (NDI) was selected as the <span class="hlt">model</span> two-phase material for this study because it contains a large and readily identifiable second- phase particle population. Second-phase particles serve as the primary void nucleation sites in NDI and are, therefore, central to its ductile spall response. A mathematical <span class="hlt">model</span> was developed for the NDI second-phase volume fraction that accounted for the non-uniform particle size and spacing distributions within the framework of a length-scale dependent Gaussian probability distribution function (PDF). This <span class="hlt">model</span> was based on novel multiscale sampling measurements. A methodology was also developed for the computer generation of representative particle structures based on their mathematical description, enabling 3D MSS. MSS were used to investigate the effects of second-phase particle volume fraction and particle size, loading conditions, and physical domain size of simulation on the ductile spall response of a <span class="hlt">model</span> two-phase material. MSS results reinforce existing <span class="hlt">model</span> predictions, where the spall strength metric (SSM) logarithmically decreases with increasing particle volume fraction. While SSM predictions are nearly independent of applied load conditions at lower loading rates, which is consistent with previous studies, loading dependencies are observed at higher loading rates. There is also a logarithmic decrease in SSM for increasing (initial) void size, as well. A <span class="hlt">model</span> was developed to account for the effects of loading rate, particle size, matrix sound-speed, and, in the NDI-specific case, the probabilistic particle volume fraction <span class="hlt">model</span>. Small-scale spall experiments were designed</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2008PhDT.......254S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2008PhDT.......254S"><span id="translatedtitle"><span class="hlt">Meso-scale</span> <span class="hlt">modeling</span> of spall in a heterogeneous two-phase material</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Springer, Harry Keo</p> <p></p> <p>The influence of the heterogeneous second-phase particle structure and applied loading conditions on the ductile spall response of a <span class="hlt">model</span> two-phase material was investigated. Quantitative metallography, three-dimensional (3D) <span class="hlt">meso-scale</span> simulations (MSS), and small-scale spall experiments provided the foundation for this study. Nodular ductile iron (NDI) was selected as the <span class="hlt">model</span> two-phase material for this study because it contains a large and readily identifiable second-phase particle population. Second-phase particles serve as the primary void nucleation sites in NDI and are, therefore, central to its ductile spall response. A mathematical <span class="hlt">model</span> was developed for the NDI second-phase volume fraction that accounted for the non-uniform particle size and spacing distributions within the framework of a length-scale dependent Gaussian probability distribution function (PDF). This <span class="hlt">model</span> was based on novel multi-scale sampling measurements. A methodology was also developed for the computer generation of representative particle structures based on their mathematical description, enabling 3D MSS. MSS were used to investigate the effects of second-phase particle volume fraction and particle size, loading conditions, and physical domain size of simulation on the ductile spall response of a <span class="hlt">model</span> two-phase material. MSS results reinforce existing <span class="hlt">model</span> predictions, where the spall strength metric (SSM) logarithmically decreases with increasing particle volume fraction. While SSM predictions are nearly independent of applied load conditions at lower loading rates, which is consistent with previous studies, loading dependencies are observed at higher loading rates. There is also a logarithmic decrease in SSM for increasing (initial) void size, as well. A <span class="hlt">model</span> was developed to account for the effects of loading rate, particle size, matrix sound-speed, and, in the NDI-specific case, the probabilistic particle volume fraction <span class="hlt">model</span>. Small-scale spall experiments were designed</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_13");'>13</a></li> <li><a href="#" onclick='return showDiv("page_14");'>14</a></li> <li class="active"><span>15</span></li> <li><a href="#" onclick='return showDiv("page_16");'>16</a></li> <li><a href="#" onclick='return showDiv("page_17");'>17</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_15 --> <div id="page_16" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_14");'>14</a></li> <li><a href="#" onclick='return showDiv("page_15");'>15</a></li> <li class="active"><span>16</span></li> <li><a href="#" onclick='return showDiv("page_17");'>17</a></li> <li><a href="#" onclick='return showDiv("page_18");'>18</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="301"> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.nwrc.usgs.gov/wdb/pub/hsi/hsi-151.pdf','USGSPUBS'); return false;" href="http://www.nwrc.usgs.gov/wdb/pub/hsi/hsi-151.pdf"><span id="translatedtitle">Habitat Suitability Index <span class="hlt">Models</span>: Diamondback Terrapin (<span class="hlt">Nesting</span>) - Atlantic Coast</span></a></p> <p><a target="_blank" href="http://pubs.er.usgs.gov/pubs/index.jsp?view=adv">USGS Publications Warehouse</a></p> <p>Palmer, William M.; Cordes, Carroll L.</p> <p>1988-01-01</p> <p>A review and synthesis of existing information were used to develop a Habitat Suitability Index (HSI) <span class="hlt">model</span> for the diamondback terrapin (Malaclemys terrapin). The <span class="hlt">model</span> consolidates habitat use information into a framework appropriate for field application, and is scaled to produce an index between 0.0 (unsuitable habitat) to 1.0 (optimum habitat). HSI <span class="hlt">models</span> are designed to be used with Habitat Evaluation Procedures previously developed by the U.S. Fish and Wildlife Service.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4435188','PMC'); return false;" href="http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4435188"><span id="translatedtitle">Detection of Bird <span class="hlt">Nests</span> during Mechanical Weeding by Incremental Background <span class="hlt">Modeling</span> and Visual Saliency</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Steen, Kim Arild; Therkildsen, Ole Roland; Green, Ole; Karstoft, Henrik</p> <p>2015-01-01</p> <p>Mechanical weeding is an important tool in organic farming. However, the use of mechanical weeding in conventional agriculture is increasing, due to public demands to lower the use of pesticides and an increased number of pesticide-resistant weeds. Ground <span class="hlt">nesting</span> birds are highly susceptible to farming operations, like mechanical weeding, which may destroy the <span class="hlt">nests</span> and reduce the survival of chicks and incubating females. This problem has limited focus within agricultural engineering. However, when the number of machines increases, destruction of <span class="hlt">nests</span> will have an impact on various species. It is therefore necessary to explore and develop new technology in order to avoid these negative ethical consequences. This paper presents a vision-based approach to automated ground <span class="hlt">nest</span> detection. The algorithm is based on the fusion of visual saliency, which mimics human attention, and incremental background <span class="hlt">modeling</span>, which enables foreground detection with moving cameras. The algorithm achieves a good detection rate, as it detects 28 of 30 <span class="hlt">nests</span> at an average distance of 3.8 m, with a true positive rate of 0.75. PMID:25738766</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2006SPIE.6364E..02F','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2006SPIE.6364E..02F"><span id="translatedtitle">Measurements of refractive variability in the marine boundary layer in comparison with <span class="hlt">mesoscale</span> meteorological <span class="hlt">model</span> predictions</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Förster, J.; Riechen, J.</p> <p>2006-09-01</p> <p>In the marine boundary layer, air-sea interaction processes have an impact on radar and infrared propagation. Range performance near the sea surface depends on the meteorological conditions and sea surface roughness. Strong gradients of humidity and temperature close to the air-water interface are most often the reason for abnormal propagation effects such as ducting or mirage. For ship borne radars the evaporation duct is the dominant propagation mechanism affecting the maximum detection range of horizon-search radars. Ducting can also increase sea clutter return within and beyond the geometric horizon. Surface-based ducts can enhance land clutter return from extended ranges. During a sea trial in the Baltic Sea in 2005, FWG characterized the environmental boundary layer. In-situ measurements included recordings of atmospheric and sea surface parameters. Simultaneous investigations were carried out at the land based test site and on board two ships. Based on FWG-buoy measurements and radiosoundings the sea surface and meteorological conditions were analyzed to study refractive variability within the maritime boundary layer. We compared measurement results with predictions of the <span class="hlt">mesoscale</span> meteorological Local <span class="hlt">Model</span> (LM), developed by German Weather Service. Radar propagation was measured in addition to atmospheric conditions. A research vessel was illuminated by radar operating at X-band on outbound and inbound runs. The radar system was located at the pier of the land based test site. Radar propagation characteristics were measured on board the ship with two omni directional antennas mounted in 5.5 m and 16.8 m height above mean sea level. Results of refractive variability are presented in conjunction with radar propagation data and <span class="hlt">model</span> outputs.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2010PhDT.........5H','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2010PhDT.........5H"><span id="translatedtitle">On the relative performance of one-way and two-way grid <span class="hlt">nesting</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Harris, Lucas M.</p> <p></p> <p>Most <span class="hlt">mesoscale</span> <span class="hlt">models</span> can be run with either one-way ("parasitic") or two-way ("interactive") grid <span class="hlt">nesting</span>. This paper presents results from a linear 1D shallow-water <span class="hlt">model</span> and from 3D simulations of a multicell thunderstorm and of trapped lee waves to determine whether the choice of <span class="hlt">nesting</span> method can have a significant impact on the solution. In the shallow-water <span class="hlt">model</span>, two-way <span class="hlt">nesting</span> was found to be generally superior to one-way <span class="hlt">nesting</span>. The increased reflection for longer-wavelength disturbances in the one-way case is due to a phase difference between the coarse- and <span class="hlt">nested</span>-grid solutions at the <span class="hlt">nested</span>-grid boundary that accumulates because of the difference in numerical phase speeds between the grids. Reflections for two-way <span class="hlt">nesting</span> may be estimated from the difference in numerical group velocities between the coarse and <span class="hlt">nested</span> grids, which only becomes large for waves that are poorly-resolved on the coarse grid. The only situation in which one-way <span class="hlt">nesting</span> performs better than two-way is when very poorly-resolved waves strike the <span class="hlt">nest</span> boundary; in these cases, using a filter on the coarse-grid values within the sponge zone of an otherwise conventional sponge boundary condition can greatly reduce the reflections caused by two-way <span class="hlt">nesting</span>. The results were more equivocal for the 3D simulations. Two-way <span class="hlt">nesting</span> clearly produced smaller precipitation errors than did one-way <span class="hlt">nesting</span> in the multicell simulations, due to the lack of mismatch errors between the coarse- and <span class="hlt">nested</span>-grid solutions in the two-way simulations. In the trapped lee-wave simulations, two-way <span class="hlt">nesting</span> produced lower overall errors than did one-way <span class="hlt">nesting</span> when a simple interpolation BC was used, but larger errors when the sponge BC was used.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/19920002516','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19920002516"><span id="translatedtitle">One-way <span class="hlt">nesting</span> for a primitive equation ocean <span class="hlt">model</span></span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Blake, D. W.</p> <p>1991-01-01</p> <p>Prognostic numerical <span class="hlt">models</span> for atmospheric and oceanic circulations require initial fields, boundary conditions, and forcing functions in addition to a consistent set of partial differential equations, including a state relation and equations expressing conservation of mass, momentum, and energy. Depending on the horizontal domain to be <span class="hlt">modeled</span>, the horizontal boundary conditions are either physically obvious or extremely difficult to specify consistently. If the entire atmosphere is <span class="hlt">modeled</span>, periodic horizontal boundary conditions are appropriate. On the other hand, the physical horizontal boundaries on the entire ocean are solid walls. Obviously, the normal velocity at a solid wall is zero while the specification of the tangential velocity depends on the mathematical treatment of the horizontal viscous terms. Limitations imposed by computer capacity and cost, as well as research interests, have led to the use of limited area <span class="hlt">models</span> to study flows in the atmosphere and ocean. The limited area <span class="hlt">models</span> do not have physical horizontal boundaries, merely numerical ones. Correctly determining these open boundary conditions for limited-area numerical <span class="hlt">models</span> has both intrigued and frustrated numerical <span class="hlt">modelers</span> for decades. One common approach is to use the closed or solid wall boundary conditions for a limited-area <span class="hlt">model</span>. The argument given for this approach is that the boundary conditions affect flow near the walls but that none of these effects are propagated into the interior. Therefore, one chooses a big enough domain that the central region of interest is not corrupted by the boundary flow. Research in progress to <span class="hlt">model</span> the North Atlantic circulation vividly illustrates the pitfalls of this approach. Two <span class="hlt">model</span> runs are compared: (1) the southern boundary at 20S between latitudes 0 and 40W is artificially closed; and (2) the same boundary is specified as open with an inward transport of 15 Sv (determined from a global <span class="hlt">model</span> with the same physics) uniformly spread</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://cfpub.epa.gov/si/si_public_record_report.cfm?dirEntryId=33845&keyword=magnitudes+AND+derived&actType=&TIMSType=+&TIMSSubTypeID=&DEID=&epaNumber=&ntisID=&archiveStatus=Both&ombCat=Any&dateBeginCreated=&dateEndCreated=&dateBeginPublishedPresented=&dateEndPublishedPresented=&dateBeginUpdated=&dateEndUpdated=&dateBeginCompleted=&dateEndCompleted=&personID=&role=Any&journalID=&publisherID=&sortBy=revisionDate&count=50&CFID=73432110&CFTOKEN=84722462','EPA-EIMS'); return false;" href="http://cfpub.epa.gov/si/si_public_record_report.cfm?dirEntryId=33845&keyword=magnitudes+AND+derived&actType=&TIMSType=+&TIMSSubTypeID=&DEID=&epaNumber=&ntisID=&archiveStatus=Both&ombCat=Any&dateBeginCreated=&dateEndCreated=&dateBeginPublishedPresented=&dateEndPublishedPresented=&dateBeginUpdated=&dateEndUpdated=&dateBeginCompleted=&dateEndCompleted=&personID=&role=Any&journalID=&publisherID=&sortBy=revisionDate&count=50&CFID=73432110&CFTOKEN=84722462"><span id="translatedtitle">SENSITIVITY ANALYSIS OF A <span class="hlt">NESTED</span> OZONE AIR QUALITY <span class="hlt">MODEL</span></span></a></p> <p><a target="_blank" href="http://oaspub.epa.gov/eims/query.page">EPA Science Inventory</a></p> <p></p> <p></p> <p>A series of Urban Airshed <span class="hlt">Model</span> (UAM) simulations were performed using inputs derived from Regional Oxidant <span class="hlt">Model</span> (ROM) data files. The gridded ROM results employed in the UAM simulations included concentrations for specifying initial and boundary conditions, wind fields, other m...</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2010PhDT........82F&link_type=ABSTRACT','NASAADS'); return false;" href="http://adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2010PhDT........82F&link_type=ABSTRACT"><span id="translatedtitle"><span class="hlt">Mesoscale</span> <span class="hlt">modeling</span> of the urban boundary layer in a coastal environment</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Flagg, David D.</p> <p></p> <p><span class="hlt">Mesoscale</span> <span class="hlt">modeling</span> of the urban boundary layer requires careful parameterization of the surface due to its heterogeneous morphology. <span class="hlt">Model</span> estimated meteorological quantities will respond accordingly to the scale of representation. Urban areas also act as enhanced energy sources, often provoking an urban heat island circulation. The presence of adjacent coastlines can introduce an additional vertical circulation, the sea breeze or lake breeze. The Detroit-Windsor (U.S.A -- Canada) metropolitan area is one such urban area susceptible to these circulations. In the first component of this study, a new set of urban surface images created from multiple sources is created to represent the surface at varying scales in a numerical weather prediction <span class="hlt">model</span> (Weather Research and Forecasting <span class="hlt">Model</span>) coupled with a single-layer urban canopy <span class="hlt">model</span>. <span class="hlt">Model</span> estimates using the finest surface representation scale (˜ 308 m) are verified using measurements from the Border Air Quality Study (BAQSMet) 2007 (southwestern Ontario, Canada) and Joint Urban 2003 (Oklahoma City, U.S.A.) field campaigns. The second component of this study examines the sensitivity of the surface energy budget, canopy layer and boundary layer meteorology to the scale of urban surface representation at Detroit-Windsor during several dry, c1oudfree summer periods. Case studies span from 'neighborhood' (˜ 308 m) to very coarse (˜ 3.7 km) surface resolution with constant <span class="hlt">model</span> resolution. Results indicate high sensitivity in turbulent latent heat flux from the natural surface and sensible heat flux from the urban canopy. Small scale change is also shown to delay timing of a lake-breeze front passage and can significantly affect the timing of local transition in static stability. The third component of this study evaluates the presence of urban heat island and lake breeze circulations in the vicinity of Detroit-Windsor over two dates during BAQSMet 2007. Varying strength of the urban heat island circulation</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://elibrary.unm.edu/sora/Wilson/v093n01/p0042-p0053.pdf','USGSPUBS'); return false;" href="http://elibrary.unm.edu/sora/Wilson/v093n01/p0042-p0053.pdf"><span id="translatedtitle">The Mayfield method of estimating <span class="hlt">nesting</span> success: A <span class="hlt">model</span>, estimators and simulation results</span></a></p> <p><a target="_blank" href="http://pubs.er.usgs.gov/pubs/index.jsp?view=adv">USGS Publications Warehouse</a></p> <p>Hensler, G.L.; Nichols, J.D.</p> <p>1981-01-01</p> <p>Using a <span class="hlt">nesting</span> <span class="hlt">model</span> proposed by Mayfield we show that the estimator he proposes is a maximum likelihood estimator (m.l.e.). M.l.e. theory allows us to calculate the asymptotic distribution of this estimator, and we propose an estimator of the asymptotic variance. Using these estimators we give approximate confidence intervals and tests of significance for daily survival. Monte Carlo simulation results show the performance of our estimators and tests under many sets of conditions. A traditional estimator of <span class="hlt">nesting</span> success is shown to be quite inferior to the Mayfield estimator. We give sample sizes required for a given accuracy under several sets of conditions.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/25879530','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/25879530"><span id="translatedtitle">NEMix: single-cell <span class="hlt">nested</span> effects <span class="hlt">models</span> for probabilistic pathway stimulation.</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Siebourg-Polster, Juliane; Mudrak, Daria; Emmenlauer, Mario; Rämö, Pauli; Dehio, Christoph; Greber, Urs; Fröhlich, Holger; Beerenwinkel, Niko</p> <p>2015-04-01</p> <p><span class="hlt">Nested</span> effects <span class="hlt">models</span> have been used successfully for learning subcellular networks from high-dimensional perturbation effects that result from RNA interference (RNAi) experiments. Here, we further develop the basic <span class="hlt">nested</span> effects <span class="hlt">model</span> using high-content single-cell imaging data from RNAi screens of cultured cells infected with human rhinovirus. RNAi screens with single-cell readouts are becoming increasingly common, and they often reveal high cell-to-cell variation. As a consequence of this cellular heterogeneity, knock-downs result in variable effects among cells and lead to weak average phenotypes on the cell population level. To address this confounding factor in network inference, we explicitly <span class="hlt">model</span> the stimulation status of a signaling pathway in individual cells. We extend the framework of <span class="hlt">nested</span> effects <span class="hlt">models</span> to probabilistic combinatorial knock-downs and propose NEMix, a <span class="hlt">nested</span> effects mixture <span class="hlt">model</span> that accounts for unobserved pathway activation. We analyzed the identifiability of NEMix and developed a parameter inference scheme based on the Expectation Maximization algorithm. In an extensive simulation study, we show that NEMix improves learning of pathway structures over classical NEMs significantly in the presence of hidden pathway stimulation. We applied our <span class="hlt">model</span> to single-cell imaging data from RNAi screens monitoring human rhinovirus infection, where limited infection efficiency of the assay results in uncertain pathway stimulation. Using a subset of genes with known interactions, we show that the inferred NEMix network has high accuracy and outperforms the classical <span class="hlt">nested</span> effects <span class="hlt">model</span> without hidden pathway activity. NEMix is implemented as part of the R/Bioconductor package 'nem' and available at www.cbg.ethz.ch/software/NEMix. PMID:25879530</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4400057','PMC'); return false;" href="http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4400057"><span id="translatedtitle">NEMix: Single-cell <span class="hlt">Nested</span> Effects <span class="hlt">Models</span> for Probabilistic Pathway Stimulation</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Siebourg-Polster, Juliane; Mudrak, Daria; Emmenlauer, Mario; Rämö, Pauli; Dehio, Christoph; Greber, Urs; Fröhlich, Holger; Beerenwinkel, Niko</p> <p>2015-01-01</p> <p><span class="hlt">Nested</span> effects <span class="hlt">models</span> have been used successfully for learning subcellular networks from high-dimensional perturbation effects that result from RNA interference (RNAi) experiments. Here, we further develop the basic <span class="hlt">nested</span> effects <span class="hlt">model</span> using high-content single-cell imaging data from RNAi screens of cultured cells infected with human rhinovirus. RNAi screens with single-cell readouts are becoming increasingly common, and they often reveal high cell-to-cell variation. As a consequence of this cellular heterogeneity, knock-downs result in variable effects among cells and lead to weak average phenotypes on the cell population level. To address this confounding factor in network inference, we explicitly <span class="hlt">model</span> the stimulation status of a signaling pathway in individual cells. We extend the framework of <span class="hlt">nested</span> effects <span class="hlt">models</span> to probabilistic combinatorial knock-downs and propose NEMix, a <span class="hlt">nested</span> effects mixture <span class="hlt">model</span> that accounts for unobserved pathway activation. We analyzed the identifiability of NEMix and developed a parameter inference scheme based on the Expectation Maximization algorithm. In an extensive simulation study, we show that NEMix improves learning of pathway structures over classical NEMs significantly in the presence of hidden pathway stimulation. We applied our <span class="hlt">model</span> to single-cell imaging data from RNAi screens monitoring human rhinovirus infection, where limited infection efficiency of the assay results in uncertain pathway stimulation. Using a subset of genes with known interactions, we show that the inferred NEMix network has high accuracy and outperforms the classical <span class="hlt">nested</span> effects <span class="hlt">model</span> without hidden pathway activity. NEMix is implemented as part of the R/Bioconductor package ‘nem’ and available at www.cbg.ethz.ch/software/NEMix. PMID:25879530</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2015FlDyR..47e1401I&link_type=ABSTRACT','NASAADS'); return false;" href="http://adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2015FlDyR..47e1401I&link_type=ABSTRACT"><span id="translatedtitle">Variational data assimilation system with <span class="hlt">nesting</span> <span class="hlt">model</span> for high resolution ocean circulation</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Ishikawa, Yoichi; In, Teiji; Nakada, Satoshi; Nishina, Kei; Igarashi, Hiromichi; Hiyoshi, Yoshimasa; Sasaki, Yuji; Wakamatsu, Tsuyoshi; Awaji, Toshiyuki</p> <p>2015-10-01</p> <p>To obtain the high-resolution analysis fields for ocean circulation, a new incremental approach is developed using a four-dimensional variational data assimilation system with <span class="hlt">nesting</span> <span class="hlt">models</span>. The results show that there are substantial biases when using a classical method combined with data assimilation and downscaling, caused by different dynamics resulting from the different resolutions of the <span class="hlt">models</span> used within the <span class="hlt">nesting</span> <span class="hlt">models</span>. However, a remarkable reduction in biases of the low-resolution <span class="hlt">model</span> relative to the high-resolution <span class="hlt">model</span> was observed using our new approach in narrow strait regions, such as the Tsushima and Tsugaru straits, where the difference in the dynamics represented by the high- and low-resolution <span class="hlt">models</span> is substantial. In addition, error reductions are demonstrated in the downstream region of these narrow channels associated with the propagation of information through the <span class="hlt">model</span> dynamics.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4632542','PMC'); return false;" href="http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4632542"><span id="translatedtitle">Computational <span class="hlt">model</span> of collective <span class="hlt">nest</span> selection by ants with heterogeneous acceptance thresholds</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Masuda, Naoki; O'shea-Wheller, Thomas A.; Doran, Carolina; Franks, Nigel R.</p> <p>2015-01-01</p> <p>Collective decision-making is a characteristic of societies ranging from ants to humans. The ant Temnothorax albipennis is known to use quorum sensing to collectively decide on a new home; emigration to a new <span class="hlt">nest</span> site occurs when the number of ants favouring the new site becomes quorate. There are several possible mechanisms by which ant colonies can select the best <span class="hlt">nest</span> site among alternatives based on a quorum mechanism. In this study, we use computational <span class="hlt">models</span> to examine the implications of heterogeneous acceptance thresholds across individual ants in collective <span class="hlt">nest</span> choice behaviour. We take a minimalist approach to develop a differential equation <span class="hlt">model</span> and a corresponding non-spatial agent-based <span class="hlt">model</span>. We show, consistent with existing empirical evidence, that heterogeneity in acceptance thresholds is a viable mechanism for efficient <span class="hlt">nest</span> choice behaviour. In particular, we show that the proposed <span class="hlt">models</span> show speed–accuracy trade-offs and speed–cohesion trade-offs when we vary the number of scouts or the quorum threshold. PMID:26543578</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/26543578','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/26543578"><span id="translatedtitle">Computational <span class="hlt">model</span> of collective <span class="hlt">nest</span> selection by ants with heterogeneous acceptance thresholds.</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Masuda, Naoki; O'shea-Wheller, Thomas A; Doran, Carolina; Franks, Nigel R</p> <p>2015-06-01</p> <p>Collective decision-making is a characteristic of societies ranging from ants to humans. The ant Temnothorax albipennis is known to use quorum sensing to collectively decide on a new home; emigration to a new <span class="hlt">nest</span> site occurs when the number of ants favouring the new site becomes quorate. There are several possible mechanisms by which ant colonies can select the best <span class="hlt">nest</span> site among alternatives based on a quorum mechanism. In this study, we use computational <span class="hlt">models</span> to examine the implications of heterogeneous acceptance thresholds across individual ants in collective <span class="hlt">nest</span> choice behaviour. We take a minimalist approach to develop a differential equation <span class="hlt">model</span> and a corresponding non-spatial agent-based <span class="hlt">model</span>. We show, consistent with existing empirical evidence, that heterogeneity in acceptance thresholds is a viable mechanism for efficient <span class="hlt">nest</span> choice behaviour. In particular, we show that the proposed <span class="hlt">models</span> show speed-accuracy trade-offs and speed-cohesion trade-offs when we vary the number of scouts or the quorum threshold. PMID:26543578</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://eric.ed.gov/?q=nms&id=EJ910601','ERIC'); return false;" href="http://eric.ed.gov/?q=nms&id=EJ910601"><span id="translatedtitle">The Structure of Academic Self-Concepts Revisited: The <span class="hlt">Nested</span> Marsh/Shavelson <span class="hlt">Model</span></span></a></p> <p><a target="_blank" href="http://www.eric.ed.gov/ERICWebPortal/search/extended.jsp?_pageLabel=advanced">ERIC Educational Resources Information Center</a></p> <p>Brunner, Martin; Keller, Ulrich; Dierendonck, Christophe; Reichert, Monique; Ugen, Sonja; Fischbach, Antoine; Martin, Romain</p> <p>2010-01-01</p> <p>The <span class="hlt">nested</span> Marsh/Shavelson (NMS) <span class="hlt">model</span> integrates structural characteristics of academic self-concepts that have proved empirically incompatible in previous studies. Specifically, it conceives of academic self-concepts to be subject specific, strongly separated across domains, and hierarchically organized, with general academic self-concept at the…</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ars.usda.gov/research/publications/Publications.htm?seq_no_115=195433','TEKTRAN'); return false;" href="http://www.ars.usda.gov/research/publications/Publications.htm?seq_no_115=195433"><span id="translatedtitle"><span class="hlt">NESTED</span> THRESHOLD SIRE <span class="hlt">MODELS</span> FOR ESTIMATING GENETIC PARAMETERS FOR STAYABILITY IN BEEF COWS</span></a></p> <p><a target="_blank" href="http://www.ars.usda.gov/services/TekTran.htm">Technology Transfer Automated Retrieval System (TEKTRAN)</a></p> <p></p> <p></p> <p>Stayability is the ability of a beef cow to remain in production to a specified age. In this study, the interest was in determining the genetic relationship between stayability to an early age with the stayability to a later age. A <span class="hlt">nested</span> threshold sire <span class="hlt">model</span> for stayability was used to estimate t...</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://cfpub.epa.gov/si/si_public_record_report.cfm?dirEntryId=266456&keyword=productivity&actType=&TIMSType=+&TIMSSubTypeID=&DEID=&epaNumber=&ntisID=&archiveStatus=Both&ombCat=Any&dateBeginCreated=&dateEndCreated=&dateBeginPublishedPresented=&dateEndPublishedPresented=&dateBeginUpdated=&dateEndUpdated=&dateBeginCompleted=&dateEndCompleted=&personID=&role=Any&journalID=&publisherID=&sortBy=revisionDate&count=50&CFID=65360668&CFTOKEN=60344154','EPA-EIMS'); return false;" href="http://cfpub.epa.gov/si/si_public_record_report.cfm?dirEntryId=266456&keyword=productivity&actType=&TIMSType=+&TIMSSubTypeID=&DEID=&epaNumber=&ntisID=&archiveStatus=Both&ombCat=Any&dateBeginCreated=&dateEndCreated=&dateBeginPublishedPresented=&dateEndPublishedPresented=&dateBeginUpdated=&dateEndUpdated=&dateBeginCompleted=&dateEndCompleted=&personID=&role=Any&journalID=&publisherID=&sortBy=revisionDate&count=50&CFID=65360668&CFTOKEN=60344154"><span id="translatedtitle">Avian life history profiles for use in the Markov chain <span class="hlt">nest</span> productivity <span class="hlt">model</span> (MCnest)</span></a></p> <p><a target="_blank" href="http://oaspub.epa.gov/eims/query.page">EPA Science Inventory</a></p> <p></p> <p></p> <p>The Markov Chain <span class="hlt">nest</span> productivity <span class="hlt">model</span>, or MCnest, quantitatively estimates the effects of pesticides or other toxic chemicals on annual reproductive success of avian species (Bennett and Etterson 2013, Etterson and Bennett 2013). The Basic Version of MCnest was developed as a...</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014EGUGA..1612778L','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014EGUGA..1612778L"><span id="translatedtitle">Management <span class="hlt">model</span> application at <span class="hlt">nested</span> spatial levels in Mediterranean Basins</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Lo Porto, Antonio; De Girolamo, Anna Maria; Froebrich, Jochen</p> <p>2014-05-01</p> <p>In the EU Water Framework Directive (WFD) implementation processes, hydrological and water quality <span class="hlt">models</span> can be powerful tools that allow to design and test alternative management strategies, as well as judging their general feasibility and acceptance. Although in recent decades several <span class="hlt">models</span> have been developed, their use in Mediterranean basins, where rivers have a temporary character, is quite complex and there is limited information in literature which can facilitate <span class="hlt">model</span> applications and result evaluations in this region. The high spatial variability which characterizes rainfall events, soil hydrological properties and land uses of Mediterranean basin makes more difficult to simulate hydrological and water quality in this region than in other Countries. This variability also has several implications in <span class="hlt">modeling</span> simulations results especially when simulations at different spatial scale are needed for watershed management purpose. It is well known that environmental processes operating at different spatial scale determine diverse impacts on water quality status (hydrological, chemical, ecological). Hence, the development of management strategies have to include both large scale (watershed) and local spatial scales approaches (e.g. stream reach). This paper presents the results of a study which analyzes how the spatial scale affects the results of hydrologic process and water quality of <span class="hlt">model</span> simulations in a Mediterranean watershed. Several aspects involved in <span class="hlt">modeling</span> hydrological and water quality processes at different spatial scale for river basin management are investigated including <span class="hlt">model</span> data requirements, data availability, <span class="hlt">model</span> results and uncertainty. A hydrologic and water quality <span class="hlt">model</span> (SWAT) was used to simulate hydrologic processes and water quality at different spatial scales in the Candelaro river basin (Puglia, S-E Italy) and to design management strategies to reach as possible WFD goals. When studying a basin to assess its current status</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014JAMES...6..586P','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014JAMES...6..586P"><span id="translatedtitle">How does the Redi parameter for <span class="hlt">mesoscale</span> mixing impact global climate in an Earth System <span class="hlt">Model</span>?</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Pradal, Marie-Aude; Gnanadesikan, Anand</p> <p>2014-09-01</p> <p>A coupled climate <span class="hlt">model</span> is used to examine the impact of an increase in the mixing due to <span class="hlt">mesoscale</span> eddies on the global climate system. A sixfold increase in the Redi mixing coefficient ARedi, which is within the admissible range of variation, has the overall effect of warming the global-mean surface air and sea surface temperatures by more than 1°C. Locally, sea surface temperatures increase by up to 7°C in the North Pacific and by up to 4°C in the Southern Ocean, with corresponding impacts on the ice concentration and ice extent in polar regions. However, it is not clear that the changes in heat transport from tropics to poles associated with changing this coefficient are primarily responsible for these changes. We found that the changes in the transport of heat are often much smaller than changes in long-wave trapping and short-wave absorption. Additionally, changes in the advective and diffusive transport of heat toward the poles often oppose each other. However, we note that the poleward transport of salt increases near the surface as ARedi increases. We suggest a causal chain in which enhanced eddy stirring leads to increased high-latitude surface salinity reducing salt stratification and water column stability and enhancing convection, triggering two feedback loops. In one, deeper convection prevents sea ice formation, which decreases albedo, which increases SW absorption, further increasing SST and decreasing sea ice formation. In the other, increased SST and reduced sea ice allow for more water vapor in the atmosphere, trapping long-wave radiation. Destratifying the polar regions is thus a potential way in which changes in ocean circulation might warm the planet.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2013AGUFMSM11A2058H','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2013AGUFMSM11A2058H"><span id="translatedtitle">Determination of <span class="hlt">meso-scale</span> magnetotail structure using Cluster Data and nonlinear dynamics <span class="hlt">modeling</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Holland, D. L.; Martin, R. F.; Fioretto, M.; Brennan, C.</p> <p>2013-12-01</p> <p>A commonly used approximation for the quiet-time magnetotail structure is the modified Harris magnetic field, B =B0[tanh(z/δ)ex + bzez] where B0 is the magnetic field strength far from the sheet, δ is the scale length of the current sheet thickness and bz is the ratio of the magnitude of the field at the midplane to the asymptotic field. Theory and simulations using the modified Harris <span class="hlt">model</span> have predicted the existence of a signature of nonlinear charged particle dynamics that manifests itself a series of peaks in the ion distribution function. The separation of the peaks has been shown to scale as the fourth root of the normalized ion energy which in turn depends on the combination of parameters σ= bz2 δ. By measuring the location of the peaks in the ion distribution function or differential particle flux we may obtain a measured value for σ, however, we still need an independent measurement of either bz or δ to determine the <span class="hlt">meso-scale</span> current sheet structure. Using a single spacecraft, precise measurement of either parameter is difficult. The current sheet scale length is problematic since relative motion of the spacecraft and the current sheet cannot be decoupled. This difficulty may be overcome using multiple satellites such as the Cluster mission. Even with multiple spacecrafts, however, the value of the field ratio bz is still difficult to ascertain since it is a small quantity and even a small tilt to the current sheet can result in significant percentage errors. In this paper, we present a statistical analysis of the current sheet structure using Cluster FGM data to determine the current sheet thickness and pitch angle resolved ion distribution function data from the Cluster HIA instrument to determine the value of σ and hence bz. We show that the measurements are in good agreement with those using other techniques, but with a significantly lower uncertainty.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2001AGUFM.A52B0153R','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2001AGUFM.A52B0153R"><span id="translatedtitle">Transport in the Region of the Subtropical Jet Deduced From WB-57 Measurements and <span class="hlt">Mesoscale</span> <span class="hlt">Modeling</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Ray, E.; Ray, E.; Rosenlof, K. H.</p> <p>2001-12-01</p> <p>Recent WB-57 missions have provided a wealth of long-lived tracer and aerosol measurements in the upper troposphere and lower stratosphere. In this study we use in situ water vapor, ozone and meteorological measurements as well as vertical sounding data to investigate transport in the region of the subtopical jet. In addition, <span class="hlt">mesoscale</span> <span class="hlt">model</span> simulations from the NCAR MM5 are utilized to attempt to reproduce the observations and help determine possible mechanisms of transport. We focus on the flight of May 7, 1998 since it has several interesting features in the measurements taken as the flight crossed a jet exit region at roughly the 370 K level. On the tropical side of the jet, low water vapor and relatively high ozone mixing ratios were measured suggesting the air in this region had stratospheric characteristics. Yet according to MM5 output this region is well within the troposphere. Within the jet the water vapor mixing ratios are highly variable, with some mixing ratios higher than those measured on either side of the jet at the same isentropic level. This suggests that perhaps there was more vertical mixing within the jet than on either side of the jet. A third interesting feature in the measurements is seen several hundred km north of the jet just as the plane began to rise in altitude. Between 370-390K the water vapor increased sharply and the ozone decreased sharply at the same time the MTP instrument indicated the tropopause level had risen from 345 K to 370 K in less than 50 km. This feature is highly suggestive of a small filament of upper tropospheric air which has been transported to the north side of the jet. Each of these features is compared to MM5 output and trajectory analyses.</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_14");'>14</a></li> <li><a href="#" onclick='return showDiv("page_15");'>15</a></li> <li class="active"><span>16</span></li> <li><a href="#" onclick='return showDiv("page_17");'>17</a></li> <li><a href="#" onclick='return showDiv("page_18");'>18</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_16 --> <div id="page_17" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_15");'>15</a></li> <li><a href="#" onclick='return showDiv("page_16");'>16</a></li> <li class="active"><span>17</span></li> <li><a href="#" onclick='return showDiv("page_18");'>18</a></li> <li><a href="#" onclick='return showDiv("page_19");'>19</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="321"> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014AGUFM.B23D0233H','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014AGUFM.B23D0233H"><span id="translatedtitle">Monitoring and <span class="hlt">Modeling</span> Microbial Sulfate Reduction and Inhibition in a <span class="hlt">Mesoscale</span> Tank Experiment</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Hubbard, C. G.; Wu, Y.; Li, L.; Piceno, Y. M.; Cheng, Y.; Bill, M.; Coates, J. D.; Andersen, G. L.; Conrad, M. E.; Ajo Franklin, J. B.</p> <p>2014-12-01</p> <p>Subsurface biogeochemical cycling at the field-scale is controlled by a complex interplay between hydrological, geochemical and biological parameters. <span class="hlt">Mesoscale</span> tank experiments can help to bridge the gap in complexity and understanding between well constrained batch and column experiments, and the interpretation of field data. In this contribution we present the results of a tank experiment investigating microbial sulfate reduction and inhibition in a porous media (20-30 mesh Ottawa sand). Microbial sulfate reduction is a process of wide biogeochemical significance, including in the context of oil reservoirs where the generation of sulfide can result in corrosion of steel infrastructure and additional downstream processing. Inhibition of sulfate reduction is therefore a high priority for this industry. Tracer experiments were conducted at the start and end of the experiment to constrain flow pathways and heterogeneities. The tank was inoculated with a San Francisco Bay mud/water enrichment utilizing acetate as the electron donor and continuous flow was initiated using bay-water with 10 mM acetate. Samples were taken from an array of 12 steel boreholes and showed spatiotemporal heterogeneities in the development of sulfidogenesis, reaching a peak of ~5 mM dissolved sulfide 71 days after inoculation. 10 mM perchlorate was then added to the influent to inhibit sulfidogenesis and dissolved sulfide decreased to ~0.03 mM by day 95. Stable isotope analysis of dissolved sulfate showed an increase in δ34S by ~10‰ compared with influent values but δ34S did not return to influent values by day 95, which may be indicative of the mixing between new and residual sulfate in the tank. Ongoing microbial community analyses are being used to help constrain microbial metabolisms. Finally, all the data is being integrated into a reactive transport <span class="hlt">model</span> to better constrain the observed interplay between hydrology, geochemistry and biology.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4084988','PMC'); return false;" href="http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4084988"><span id="translatedtitle">Food Provisioning and Parental Status in Songbirds: Can Occupancy <span class="hlt">Models</span> Be Used to Estimate <span class="hlt">Nesting</span> Performance?</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Corbani, Aude Catherine; Hachey, Marie-Hélène; Desrochers, André</p> <p>2014-01-01</p> <p>Indirect methods to estimate parental status, such as the observation of parental provisioning, have been problematic due to potential biases associated with imperfect detection. We developed a method to evaluate parental status based on a novel combination of parental provisioning observations and hierarchical <span class="hlt">modeling</span>. In the summers of 2009 to 2011, we surveyed 393 sites, each on three to four consecutive days at Forêt Montmorency, Québec, Canada. We assessed parental status of 2331 adult songbirds based on parental food provisioning. To account for imperfect detection of parental status, we applied MacKenzie et al.'s (2002) two-state hierarchical <span class="hlt">model</span> to obtain unbiased estimates of the proportion of sites with successfully <span class="hlt">nesting</span> birds, and the proportion of adults with offspring. To obtain an independent evaluation of detection probability, we monitored 16 active <span class="hlt">nests</span> in 2010 and conducted parental provisioning observations away from them. The probability of detecting food provisioning was 0.31 when using <span class="hlt">nest</span> monitoring, a value within the 0.11 to 0.38 range that was estimated by two-state <span class="hlt">models</span>. The proportion of adults or sites with broods approached 0.90 and varied depending on date during the sampling season and year, exemplifying the role of eastern boreal forests as highly productive <span class="hlt">nesting</span> grounds for songbirds. This study offers a simple and effective sampling design for studying avian reproductive performance that could be implemented in national surveys such as breeding bird atlases. PMID:24999969</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2011AGUFMOS43B1543H','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2011AGUFMOS43B1543H"><span id="translatedtitle"><span class="hlt">Mesoscale</span> Eddies in the Solomon Sea</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Hristova, H. G.; Kessler, W. S.; McWilliams, J. C.; Molemaker, M. J.</p> <p>2011-12-01</p> <p>Water mass transformation in the strong equatorward flows through the Solomon Sea influences the properties of the Equatorial Undercurrent and subsequent cold tongue upwelling. High eddy activity in the interior Solomon Sea seen in altimetric sea surface height (SSH) and in several <span class="hlt">models</span> may provide a mechanism for these transformations. We investigate these effects using a <span class="hlt">mesoscale</span> (4-km resolution) sigma-coordinate (ROMS) <span class="hlt">model</span> of the Solomon Sea <span class="hlt">nested</span> in a basin solution, forced by a repeating seasonal cycle, and evaluated against observational data. The <span class="hlt">model</span> generates a vigorous upper layer eddy field; some of these are apparently shed as the New Guinea Coastal Undercurrent threads through the complex topography of the region, others are independent of the strong western boundary current. We diagnose the scales and vertical structure of the eddies in different parts of the Solomon Sea to illuminate their generation processes and propagation characteristics, and compare these to observed eddy statistics. Hypotheses tested are that the Solomon Sea <span class="hlt">mesoscale</span> eddies are generated locally by baroclinic instability, that the eddies are shed as the South Equatorial Current passes around and through the Solomon Island chain, that eddies are generated by the New Guinea Coastal Undercurrent, or that eddies occurring outside of the Solomon Sea propagate into the Solomon Sea. These different mechanisms have different implications for the resulting mixing and property fluxes. They also provide different interpretations for SSH signals observed from satellites (e.g., that will be observed by the upcoming SWOT satellite).</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://ntrs.nasa.gov/search.jsp?R=19780060143&hterms=deep+excavation&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D50%26Ntt%3Ddeep%2Bexcavation','NASA-TRS'); return false;" href="http://ntrs.nasa.gov/search.jsp?R=19780060143&hterms=deep+excavation&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D50%26Ntt%3Ddeep%2Bexcavation"><span id="translatedtitle"><span class="hlt">Nested</span>-crater <span class="hlt">model</span> of lunar ringed basins</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Wilhelms, D. E.; Hodges, C. A.; Pike, R. J.</p> <p>1977-01-01</p> <p>We propose a <span class="hlt">model</span> for the origin of impact-basin rings whereby the main topographic rim of a basin approximates the limit of excavation and inner rings approximate the rims of craters formed inside the transient crater by some perturbation in the cratering process. The cause of this complexity in transient cavities may be the presence of discontinuities in the target material. The second inward ring may have formed at the seismic discontinuity about 20 km deep in the lunar crust, and the third, innermost ring of a few large basins at the crust-mantle interface about 60 km deep. Slumping increased the original diameters of many rings and split some initially coherent rings into subsidiary or partial rings. Deformation outside the transient crater produced external arcs. This <span class="hlt">model</span> differs from prevalent hypotheses of ring formation whereby an inner ring approximates the transient crater rim and major faulting of the flank produced the outer ring structures.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016EGUGA..1812477G','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016EGUGA..1812477G"><span id="translatedtitle">Do we need full <span class="hlt">mesoscale</span> <span class="hlt">models</span> to simulate the urban heat island? A study over the city of Barcelona.</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>García-Díez, Markel; Ballester, Joan; De Ridder, Koen; Hooyberghs, Hans; Lauwaet, Dirk; Rodó, Xavier</p> <p>2016-04-01</p> <p>As most of the population lives in urban environments, the simulation of the urban climate has become an important part of the global climate change impact assessment. However, due to the high resolution required, these simulations demand a large amount of computational resources. Here we present a comparison between a simplified fast urban climate <span class="hlt">model</span> (UrbClim) and a widely used full <span class="hlt">mesoscale</span> <span class="hlt">model</span>, the Weather Research and Forecasting (WRF) <span class="hlt">model</span>, over the city of Barcelona. In order to check the advantages and disadvantages of each approach, both simulations were compared with station data and with land surface temperature observations retrieved by satellites, focusing on the urban heat island. The effect of changing the UrbClim boundary conditions was studied too, by using low resolution global reanalysis data (70 km) and a higher resolution forecast <span class="hlt">model</span> (15 km). Finally, a strict comparison of the computational resources consumed by both <span class="hlt">models</span> was carried out. Results show that, generally, the performance of the simple <span class="hlt">model</span> is comparable to or better than the <span class="hlt">mesoscale</span> <span class="hlt">model</span>. The exception are the winds and the day-to-day correlation in the reanalysis driven run, but these problems disappear when taking the boundary conditions from a higher resolution global <span class="hlt">model</span>. UrbClim was found to run 133 times faster than WRF, using 4x times higher resolution and, thus, it is an efficient solution for running long climate change simulations over large city ensembles.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://ntrs.nasa.gov/search.jsp?R=19840043466&hterms=Weather+forecasting&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D60%26Ntt%3D%2528Weather%2Bforecasting%2529','NASA-TRS'); return false;" href="http://ntrs.nasa.gov/search.jsp?R=19840043466&hterms=Weather+forecasting&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D60%26Ntt%3D%2528Weather%2Bforecasting%2529"><span id="translatedtitle">A <span class="hlt">nested</span>-grid limited-area <span class="hlt">model</span> for short term weather forecasting</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Wong, V. C.; Zack, J. W.; Kaplan, M. L.; Coats, G. D.</p> <p>1983-01-01</p> <p>The present investigation is concerned with a <span class="hlt">mesoscale</span> atmospheric simulation system (MASS), incorporating the sigma-coordinate primitive equations. The present version of this <span class="hlt">model</span> (MASS 3.0) has 14 vertical layers, with the upper boundary at 100 mb. There are 128 x 96 grid points in each layer. The earlier version of this <span class="hlt">model</span> (MASS 2.0) has been described by Kaplan et al. (1982). The current investigation provides a summary of major revisions to that version and a description of the parameterization schemes which are presently included in the <span class="hlt">model</span>. The planetary boundary layer (PBL) is considered, taking into account aspects of generalized similarity theory and free convection, the surface energy budget, the surface moisture budget, and prognostic equations for the depth h of the PBL. A cloud <span class="hlt">model</span> is discussed, giving attention to stable precipitation, and cumulus convection.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2015AGUFM.A33J0321S&link_type=ABSTRACT','NASAADS'); return false;" href="http://adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2015AGUFM.A33J0321S&link_type=ABSTRACT"><span id="translatedtitle">Short-term Climate Simulations of African Easterly Waves with a Global <span class="hlt">Mesoscale</span> <span class="hlt">Model</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Shen, B. W.</p> <p>2015-12-01</p> <p>Recent high-resolution global <span class="hlt">model</span> simulations ( Shen et al., 2010a, 2010b, 2012; 2013), which were conducted to examine the role of multiscale processes associated with tropical waves in the predictability of <span class="hlt">mesoscale</span> tropical cyclones (TCs), suggested that a large-scale system (e.g., tropical waves) can provide determinism on the prediction of TC genesis, making it possible to extend the lead time of genesis predictions. Selected cases include the relationship between (i) TC Nargis (2008) and an Equatorial Rossby wave; (ii) Hurricane Helene (2006) and an intensifying African Easterly Wave (AEW); (iii) Twin TCs (2002) and a mixed Rossby-gravity wave during an active phase of the Madden Julian Oscillation (MJO); (iv) Hurricane Sandy (2012) and tropical waves during an active phase of the MJO. In this talk, thirty-day simulations with different <span class="hlt">model</span> configurations are presented to examine the <span class="hlt">model</span>'s ability to simulate AEWs and MJOs and their association with tropical cyclogenesis. I will first discuss the simulations of the initiation and propagation of 6 consecutive AEWs in late August 2006 and the mean state of the African easterly jet (AEJ) over both Africa and downstream in the tropical Atlantic. By comparing our simulations with NCEP analysis and satellite data (e.g., TRMM), it is shown that the statistical characteristics of individual AEWs are realistically simulated with larger errors in the 5th and th AEWs. Results from the sensitivity experiments suggest the following: 1) accurate representations of non-linear interactions between the atmosphere and land processes are crucial for improving the simulations of the AEWs and the AEJ; 2) improved simulations of an individual AEW and its interaction with local environments (e.g., the Guinea Highlands) could provide determinism for hurricane formation downstream. Of interest is the potential to extend the lead time for predicting hurricane formation (e.g., a lead time of up to 22 days) as the 4th AEW is</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014AGUFM.A51D3069S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014AGUFM.A51D3069S"><span id="translatedtitle">Forecast Verification for North American <span class="hlt">Mesoscale</span> (NAM) Operational <span class="hlt">Model</span> over Karst/Non-Karst regions</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Sullivan, Z.; Fan, X.</p> <p>2014-12-01</p> <p>Karst is defined as a landscape that contains especially soluble rocks such as limestone, gypsum, and marble in which caves, underground water systems, over-time sinkholes, vertical shafts, and subterranean river systems form. The cavities and voids within a karst system affect the hydrology of the region and, consequently, can affect the moisture and energy budget at surface, the planetary boundary layer development, convection, and precipitation. Carbonate karst landscapes comprise about 40% of land areas over the continental U.S east of Tulsa, Oklahoma. Currently, due to the lack of knowledge of the effects karst has on the atmosphere, no existing weather <span class="hlt">model</span> has the capability to represent karst landscapes and to simulate its impact. One way to check the impact of a karst region on the atmosphere is to check the performance of existing weather <span class="hlt">models</span> over karst and non-karst regions. The North American <span class="hlt">Mesoscale</span> (NAM) operational forecast is the best example, of which historical forecasts were archived. Variables such as precipitation, maximum/minimum temperature, dew point, evapotranspiration, and surface winds were taken into account when checking the <span class="hlt">model</span> performance over karst versus non-karst regions. The forecast verification focused on a five-year period from 2007-2011. Surface station observations, gridded observational dataset, and North American Regional Reanalysis (for certain variables with insufficient observations) were used. Thirteen regions of differing climate, size, and landscape compositions were chosen across the Contiguous United States (CONUS) for the investigation. Equitable threat score (ETS), frequency bias (fBias), and root-mean-square error (RMSE) scores were calculated and analyzed for precipitation. RMSE and mean bias (Bias) were analyzed for other variables. ETS, fBias, and RMSE scores show generally a pattern of lower forecast skills, a greater magnitude of error, and a greater under prediction of precipitation over karst than</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3676693','PMC'); return false;" href="http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3676693"><span id="translatedtitle">Micromechanical <span class="hlt">Model</span> of a Surrogate for Collagenous Soft Tissues: Development, Validation and Analysis of <span class="hlt">Mesoscale</span> Size Effects</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Reese, Shawn P.; Ellis, Benjamin J.; Weiss, Jeffrey A.</p> <p>2013-01-01</p> <p>Aligned, collagenous tissues such as tendons and ligaments are composed primarily of water and type I collagen, organized hierarchically into nanoscale fibrils, microscale fibers and <span class="hlt">mesoscale</span> fascicles. Force transfer across scales is complex and poorly understood. Since innervation, the vasculature, damage mechanisms and mechanotransduction occur at the microscale and <span class="hlt">mesoscale</span>, understanding multiscale interactions is of high importance. This study used a physical <span class="hlt">model</span> in combination with a computational <span class="hlt">model</span> to isolate and examine the mechanisms of force transfer between scales. A collagen-based surrogate served as the physical <span class="hlt">model</span>. The surrogate consisted of extruded collagen fibers embedded within a collagen gel matrix. A micromechanical finite element <span class="hlt">model</span> of the surrogate was validated using tensile test data that was recorded using a custom tensile testing device mounted on a confocal microscope. Results demonstrated that the experimentally measured macroscale strain was not representative of the microscale strain, which was highly inhomogeneous. The micromechanical <span class="hlt">model</span>, in combination with a macroscopic continuum <span class="hlt">model</span>, revealed that the microscale inhomogeneity resulted from size effects in the presence of a constrained boundary. A sensitivity study indicated that significant scale effects would be present over a range of physiologically relevant inter-fiber spacing values and matrix material properties. The results indicate that the traditional continuum assumption is not valid for describing the macroscale behavior of the surrogate, and that boundary-induced size effects are present. PMID:23400805</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2016EGUGA..18.1480M&link_type=ABSTRACT','NASAADS'); return false;" href="http://adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2016EGUGA..18.1480M&link_type=ABSTRACT"><span id="translatedtitle"><span class="hlt">Mesoscale</span> <span class="hlt">modelling</span> methodology based on nudging to increase accuracy in WRA</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Mylonas Dirdiris, Markos; Barbouchi, Sami; Hermmann, Hugo</p> <p>2016-04-01</p> <p>The offshore wind energy has recently become a rapidly growing renewable energy resource worldwide, with several offshore wind projects in development in different planning stages. Despite of this, a better understanding of the atmospheric interaction within the marine atmospheric boundary layer (MABL) is needed in order to contribute to a better energy capture and cost-effectiveness. Light has been thrown in observational nudging as it has recently become an innovative method to increase the accuracy of wind flow <span class="hlt">modelling</span>. This particular study focuses on the observational nudging capability of Weather Research and Forecasting (WRF) and ways the uncertainty of wind flow <span class="hlt">modelling</span> in the wind resource assessment (WRA) can be reduced. Finally, an alternative way to calculate the <span class="hlt">model</span> uncertainty is pinpointed. Approach WRF <span class="hlt">mesoscale</span> <span class="hlt">model</span> will be nudged with observations from FINO3 at three different heights. The <span class="hlt">model</span> simulations with and without applying observational nudging will be verified against FINO1 measurement data at 100m. In order to evaluate the observational nudging capability of WRF two ways to derive the <span class="hlt">model</span> uncertainty will be described: one global uncertainty and an uncertainty per wind speed bin derived using the recommended practice of the IEA in order to link the <span class="hlt">model</span> uncertainty to a wind energy production uncertainty. This study assesses the observational data assimilation capability of WRF <span class="hlt">model</span> within the same vertical gridded atmospheric column. The principal aim is to investigate whether having observations up to one height could improve the simulation at a higher vertical level. The study will use objective analysis implementing a Cress-man scheme interpolation to interpolate the observation in time and in sp ace (keeping the horizontal component constant) to the gridded analysis. Then the WRF <span class="hlt">model</span> core will incorporate the interpolated variables to the "first guess" to develop a nudged simulation. Consequently, WRF with and without</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://ntrs.nasa.gov/search.jsp?R=19920031383&hterms=Scale+removal&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D20%26Ntt%3DScale%2Bremoval','NASA-TRS'); return false;" href="http://ntrs.nasa.gov/search.jsp?R=19920031383&hterms=Scale+removal&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D20%26Ntt%3DScale%2Bremoval"><span id="translatedtitle">Parameterizing <span class="hlt">mesoscale</span> and large-scale ice clouds in general circulation <span class="hlt">models</span></span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Donner, Leo J.</p> <p>1990-01-01</p> <p>The paper discusses GCM parameterizations for two types of ice clouds: (1) ice clouds formed by large-scale lifting, often of limited vertical extent but usually of large-scale horizontal extent; and (2) ice clouds formed as anvils in convective systems, often of moderate vertical extent but of <span class="hlt">mesoscale</span> size horizontally. It is shown that the former type of clouds can be parameterized with reference to an equilibrium between ice generation by deposition from vapor, and ice removal by crystal settling. The same mechanisms operate in the <span class="hlt">mesoscale</span> clouds, but the ice content in these cases is considered to be more closely linked to the moisture supplied to the anvil by cumulus towers. It is shown that a GCM can simulate widespread ice clouds of both types.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3921180','PMC'); return false;" href="http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3921180"><span id="translatedtitle">Bayesian <span class="hlt">Model</span> Comparison and Parameter Inference in Systems Biology Using <span class="hlt">Nested</span> Sampling</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Pullen, Nick; Morris, Richard J.</p> <p>2014-01-01</p> <p>Inferring parameters for <span class="hlt">models</span> of biological processes is a current challenge in systems biology, as is the related problem of comparing competing <span class="hlt">models</span> that explain the data. In this work we apply Skilling's <span class="hlt">nested</span> sampling to address both of these problems. <span class="hlt">Nested</span> sampling is a Bayesian method for exploring parameter space that transforms a multi-dimensional integral to a 1D integration over likelihood space. This approach focusses on the computation of the marginal likelihood or evidence. The ratio of evidences of different <span class="hlt">models</span> leads to the Bayes factor, which can be used for <span class="hlt">model</span> comparison. We demonstrate how <span class="hlt">nested</span> sampling can be used to reverse-engineer a system's behaviour whilst accounting for the uncertainty in the results. The effect of missing initial conditions of the variables as well as unknown parameters is investigated. We show how the evidence and the <span class="hlt">model</span> ranking can change as a function of the available data. Furthermore, the addition of data from extra variables of the system can deliver more information for <span class="hlt">model</span> comparison than increasing the data from one variable, thus providing a basis for experimental design. PMID:24523891</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/24523891','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/24523891"><span id="translatedtitle">Bayesian <span class="hlt">model</span> comparison and parameter inference in systems biology using <span class="hlt">nested</span> sampling.</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Pullen, Nick; Morris, Richard J</p> <p>2014-01-01</p> <p>Inferring parameters for <span class="hlt">models</span> of biological processes is a current challenge in systems biology, as is the related problem of comparing competing <span class="hlt">models</span> that explain the data. In this work we apply Skilling's <span class="hlt">nested</span> sampling to address both of these problems. <span class="hlt">Nested</span> sampling is a Bayesian method for exploring parameter space that transforms a multi-dimensional integral to a 1D integration over likelihood space. This approach focuses on the computation of the marginal likelihood or evidence. The ratio of evidences of different <span class="hlt">models</span> leads to the Bayes factor, which can be used for <span class="hlt">model</span> comparison. We demonstrate how <span class="hlt">nested</span> sampling can be used to reverse-engineer a system's behaviour whilst accounting for the uncertainty in the results. The effect of missing initial conditions of the variables as well as unknown parameters is investigated. We show how the evidence and the <span class="hlt">model</span> ranking can change as a function of the available data. Furthermore, the addition of data from extra variables of the system can deliver more information for <span class="hlt">model</span> comparison than increasing the data from one variable, thus providing a basis for experimental design. PMID:24523891</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2016ISPAr49B2..131V&link_type=ABSTRACT','NASAADS'); return false;" href="http://adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2016ISPAr49B2..131V&link_type=ABSTRACT"><span id="translatedtitle">The Need of <span class="hlt">Nested</span> Grids for Aerial and Satellite Images and Digital Elevation <span class="hlt">Models</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Villa, G.; Mas, S.; Fernández-Villarino, X.; Martínez-Luceño, J.; Ojeda, J. C.; Pérez-Martín, B.; Tejeiro, J. A.; García-González, C.; López-Romero, E.; Soteres, C.</p> <p>2016-06-01</p> <p>Usual workflows for production, archiving, dissemination and use of Earth observation images (both aerial and from remote sensing satellites) pose big interoperability problems, as for example: non-alignment of pixels at the different levels of the pyramids that makes it impossible to overlay, compare and mosaic different orthoimages, without resampling them and the need to apply multiple resamplings and compression-decompression cycles. These problems cause great inefficiencies in production, dissemination through web services and processing in "Big Data" environments. Most of them can be avoided, or at least greatly reduced, with the use of a common "<span class="hlt">nested</span> grid" for mutiresolution production, archiving, dissemination and exploitation of orthoimagery, digital elevation <span class="hlt">models</span> and other raster data. "<span class="hlt">Nested</span> grids" are space allocation schemas that organize image footprints, pixel sizes and pixel positions at all pyramid levels, in order to achieve coherent and consistent multiresolution coverage of a whole working area. A "<span class="hlt">nested</span> grid" must be complemented by an appropriate "tiling schema", ideally based on the "quad-tree" concept. In the last years a "de facto standard" grid and Tiling Schema has emerged and has been adopted by virtually all major geospatial data providers. It has also been adopted by OGC in its "WMTS Simple Profile" standard. In this paper we explain how the adequate use of this tiling schema as common <span class="hlt">nested</span> grid for orthoimagery, DEMs and other types of raster data constitutes the most practical solution to most of the interoperability problems of these types of data.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/biblio/467652','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/biblio/467652"><span id="translatedtitle">A non-hydrostatic <span class="hlt">modeling</span> study of the <span class="hlt">mesoscale</span> circulations induced by the Gulf Stream filament</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Xu, L.; Raman, S.; Madala, R.V.</p> <p>1994-12-31</p> <p>The Gulf Stream filament (GSF) is a warm SST anomaly associated with the Gulf Stream (GS) offshore of the eastern US. The size of a typical GSF is about 50 km in width and about 200 km in length. Despite its relatively small scale, the GSF may have a significant impact on the local weather. In this study effort is made to understand the effect of the GSF on the atmospheric <span class="hlt">mesoscale</span> circulation through numerical experiments.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015AGUFM.P22A..05L','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015AGUFM.P22A..05L"><span id="translatedtitle"><span class="hlt">Mesoscale</span> <span class="hlt">Modeling</span> of Water Vapor and Dust in Valles Marineris: Atmospheric Influences on Recurring Slope Lineae.</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Leung, C. W. S.; Rafkin, S. C.; McEwen, A. S.</p> <p>2015-12-01</p> <p>Extensive recurring slope lineae (RSL) activity has been detected in Valles Marineris on Mars and coincides with regions where water ice fogs appear [1]. The origin of the water driving RSL flow is not well understood, but observational evidence suggests atmospheric processes play a crucial role [2]. Provided the atmospheric vapor concentration is high enough, water ice fogs can form overnight if the surface temperature cools below the condensation temperature. Correlations between dust storms and flow rates suggest that atmospheric dust opacity, and its influence on air temperature, also has a significant effect on RSL activity. We investigate planetary boundary layer processes that govern the hydrological cycle and dust cycle on Mars using a <span class="hlt">mesoscale</span> atmospheric <span class="hlt">model</span> to simulate the distribution of water and dust with respect to regional atmospheric circulations. Our simulations in Valles Marineris show a curious temperature structure, where the inside of the canyon appears warmer relative to the plateaus immediately outside. For a well-mixed atmosphere, this temperature structure indicates that when the atmosphere inside the canyon is saturated and fog is present within Valles Marineris, fog and low-lying clouds should also be present on the cooler surrounding plateaus as well. However, images taken with the Mars Express High Resolution Stereo Camera (HRSC) show instances where water ice fog appeared exclusively inside the canyon. These results have important implications for the origin and concentration of water vapor in Valles Marineris, with possible connections to RSL. The potential temperatures from our simulations show a high level of stability inside the canyon produced dynamically by sinking air. However, afternoon updrafts along the canyon walls indicate that over time, water vapor within the chasm would escape along the sides of the canyon. Again, this suggests a local source or mechanism to concentrate water vapor is needed to explain the fog</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015EPSC...10..103P','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015EPSC...10..103P"><span id="translatedtitle">Meteorological Circulations at Gale Environment Through Rover Environmental Monitoring Station (REMS) Observations and <span class="hlt">Mesoscale</span> <span class="hlt">Modeling</span> (MRAMS)</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Pla-García, J.; Rafkin, S.</p> <p>2015-10-01</p> <p>Gale Crater, in which the Mars Science Laboratory (MSL) landed in August 2012, is the most topographically complex area visited to date on Mars. The meteorology within the crater may also be one of the most dynamically complex meteorological environments, because topography is thought to strongly drive the near-surface atmospheric circulations. The Rover Environmental Monitoring Station (REMS) [5] has provided some clues on the nature of the local meteorology strongly influenced by the complex topography, as predicted by numerous previous studies. The types of perturbations of pressure, air and ground temperature and wind measured by REMS have never been observed at other locations and these data provide a great opportunity to test the <span class="hlt">models</span> at the most meteorological interesting area measured to date. In an effort to better understand the atmospheric circulations of the Gale Crater, the Mars Regional Atmospheric <span class="hlt">Modeling</span> System (MRAMS)[6]was applied to the landing site region using <span class="hlt">nested</span> grids with a spacing of 330 meters on the innermost grid that is centered over the landing site. We provide a comparison of MRAMS predictions for pressure, air temperature, winds and ground temperature,to the REMS data available at the location of the Rover for sols 51-55 (Ls=180), sols 195-199 (Ls=270), sols 348-352 (Ls=0) and sols 541-545 (Ls=90), in order to provide a baseline of <span class="hlt">model</span> performance.Pressure and ground temperature provide the most robust parameters with which to test the <span class="hlt">model</span> predictions(Figures 2 and 3).</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2010EGUGA..12.2941R','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2010EGUGA..12.2941R"><span id="translatedtitle">WRF-NMM <span class="hlt">Mesoscale</span> Weather Forecast <span class="hlt">Model</span> and CALMET Meteorological Preprocessor Wind Simulations over the Mountaneous Region</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Radonjic, Zivorad; Telenta, Bosko; Chambers, Doug, ,, Dr.; Janjic, Zavisa, ,, Dr.</p> <p>2010-05-01</p> <p>An advanced <span class="hlt">mesoscale</span> WRF- NMM (Weather Research and Forecasting - Nonhydrostatic <span class="hlt">Mesoscale</span> <span class="hlt">Model</span>), was used in this application. The <span class="hlt">model</span> was performed on a fine scale resolution (3 by 3 km) over large <span class="hlt">modelling</span> domain ~ 300 by 300 km for one year of data (2004). Based on this resolution the areas with elevated wind speeds are determined. Each area identified with high wind speeds is processed with the U.S. EPA's meteorological preprocessor CALMET (part of the CALMET/CALPUFF long range regulatory system) with a fine resolution of 100 by 100 m to capture dynamic effects over the mountain region. Some limited data were available for validation. The application of the CALMET preprocessor demonstrated kinematic effects that result in increaed wind speeds above the mountains. This effect was confirmed by the measeurments with the sonic anemometers mounted on a TV tower in the study area. In addition, it was concluded that in the ridged terrain, the standard power low profile is not applicable. In addition, the WRF-NMM was tested in the same application on the resolution of 100 by 100m. The <span class="hlt">model</span> simulation was limited for one month, because of the computer time requirement. Although of limited duration, this test suggests that WRF-NMM can be applied directly, without re-processing the data through the CALMET.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/servlets/purl/1127267','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/servlets/purl/1127267"><span id="translatedtitle">Using <span class="hlt">Mesoscale</span> Weather <span class="hlt">Model</span> Output as Boundary Conditions for Atmospheric Large-Eddy Simulations and Wind-Plant Aerodynamic Simulations (Presentation)</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Churchfield, M. J.; Michalakes, J.; Vanderwende, B.; Lee, S.; Sprague, M. A.; Lundquist, J. K.; Moriarty, P. J.</p> <p>2013-10-01</p> <p>Wind plant aerodynamics are directly affected by the microscale weather, which is directly influenced by the <span class="hlt">mesoscale</span> weather. Microscale weather refers to processes that occur within the atmospheric boundary layer with the largest scales being a few hundred meters to a few kilometers depending on the atmospheric stability of the boundary layer. <span class="hlt">Mesoscale</span> weather refers to large weather patterns, such as weather fronts, with the largest scales being hundreds of kilometers wide. Sometimes microscale simulations that capture <span class="hlt">mesoscale</span>-driven variations (changes in wind speed and direction over time or across the spatial extent of a wind plant) are important in wind plant analysis. In this paper, we present our preliminary work in coupling a <span class="hlt">mesoscale</span> weather <span class="hlt">model</span> with a microscale atmospheric large-eddy simulation <span class="hlt">model</span>. The coupling is one-way beginning with the weather <span class="hlt">model</span> and ending with a computational fluid dynamics solver using the weather <span class="hlt">model</span> in coarse large-eddy simulation mode as an intermediary. We simulate one hour of daytime moderately convective microscale development driven by the <span class="hlt">mesoscale</span> data, which are applied as initial and boundary conditions to the microscale domain, at a site in Iowa. We analyze the time and distance necessary for the smallest resolvable microscales to develop.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=1692383','PMC'); return false;" href="http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=1692383"><span id="translatedtitle">A <span class="hlt">model</span> for the emergence of pillars, walls and royal chambers in termite <span class="hlt">nests</span></span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Bonabeau, E.</p> <p>1998-01-01</p> <p>A simple <span class="hlt">model</span> of the emergence of pillars in termite <span class="hlt">nests</span> by Deneubourg is modified to include several additional features that break the homogeneity of the original <span class="hlt">model</span>: (i) a convection air stream that drives molecules of pheromone along a given direction; (ii) a net flux of individuals in a specific direction; (iii) a well-defined self-maintained pheromone trail; and (iv) a pheromonal template representing the effect of the presence of a queen that continuously emits pheromone. It is shown that, under certain conditions, pillars are transformed into walls or galleries or chambers, and that this transformation may not be driven by any change in the termites' behaviour. Because the same type of response at the individual level can generate different patterns under different conditions, and because previous construction modifies current building conditions, we hypothesize that <span class="hlt">nest</span> complexity can result from the unfolding of a morphogenetic process that progressively generates a diversity of history-dependent structures.</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_15");'>15</a></li> <li><a href="#" onclick='return showDiv("page_16");'>16</a></li> <li class="active"><span>17</span></li> <li><a href="#" onclick='return showDiv("page_18");'>18</a></li> <li><a href="#" onclick='return showDiv("page_19");'>19</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_17 --> <div id="page_18" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_16");'>16</a></li> <li><a href="#" onclick='return showDiv("page_17");'>17</a></li> <li class="active"><span>18</span></li> <li><a href="#" onclick='return showDiv("page_19");'>19</a></li> <li><a href="#" onclick='return showDiv("page_20");'>20</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="341"> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2004AdAtS..21..708B','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2004AdAtS..21..708B"><span id="translatedtitle">A numerical study of a TOGA-COARE squall-line using a coupled <span class="hlt">mesoscale</span> atmosphere-ocean <span class="hlt">model</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Bao, Shaowu; Xie, Lian; Raman, Sethu</p> <p>2004-10-01</p> <p>An atmosphere-ocean coupled <span class="hlt">mesoscale</span> <span class="hlt">modeling</span> system is developed and used to investigate the interactions between a squall line and the upper ocean observed over the western Pacific warm pool during the Tropical Ocean/Global Atmosphere Coupled Ocean and Atmosphere Response Experiment (TOGA-COARE). The <span class="hlt">modeling</span> system is developed by coupling the Advanced Regional Prediction System (ARPS) to the Princeton Ocean <span class="hlt">Model</span> (POM) through precipitation and two-way exchanges of momentum, heat, and moisture across the air-sea interface. The results indicate that the interaction between the squall-line and the upper ocean produced noticeable differences in the sensible and latent heat fluxes, as compared to the uncoupled cases. Precipitation, which is often ignored in air-sea heat flux estimates, played a major role in the coupling between the <span class="hlt">mesoscale</span> convective system and the ocean. Precipitation affected the air-sea interaction through both freshwater flux and sensible heat flux. The former led to the formation of a thin stable ocean layer underneath and behind the precipitating atmospheric convection. The presence of this stable layer resulted in a more significant convection-induced sea surface temperature (SST) change in and behind the precipitation zone. However, convection-induced SST changes do not seem to play an important role in the intsensification of the existing convective system that resulted in the SST change, as the convection quickly moved away from the region of original SST response.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/20030063974','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20030063974"><span id="translatedtitle">A New Objective Technique for Verifying <span class="hlt">Mesoscale</span> Numerical Weather Prediction <span class="hlt">Models</span></span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Case, Jonathan L.; Manobianco, John; Lane, John E.; Immer, Christopher D.</p> <p>2003-01-01</p> <p>This report presents a new objective technique to verify predictions of the sea-breeze phenomenon over east-central Florida by the Regional Atmospheric <span class="hlt">Modeling</span> System (RAMS) <span class="hlt">mesoscale</span> numerical weather prediction (NWP) <span class="hlt">model</span>. The Contour Error Map (CEM) technique identifies sea-breeze transition times in objectively-analyzed grids of observed and forecast wind, verifies the forecast sea-breeze transition times against the observed times, and computes the mean post-sea breeze wind direction and speed to compare the observed and forecast winds behind the sea-breeze front. The CEM technique is superior to traditional objective verification techniques and previously-used subjective verification methodologies because: It is automated, requiring little manual intervention, It accounts for both spatial and temporal scales and variations, It accurately identifies and verifies the sea-breeze transition times, and It provides verification contour maps and simple statistical parameters for easy interpretation. The CEM uses a parallel lowpass boxcar filter and a high-order bandpass filter to identify the sea-breeze transition times in the observed and <span class="hlt">model</span> grid points. Once the transition times are identified, CEM fits a Gaussian histogram function to the actual histogram of transition time differences between the <span class="hlt">model</span> and observations. The fitted parameters of the Gaussian function subsequently explain the timing bias and variance of the timing differences across the valid comparison domain. Once the transition times are all identified at each grid point, the CEM computes the mean wind direction and speed during the remainder of the day for all times and grid points after the sea-breeze transition time. The CEM technique performed quite well when compared to independent meteorological assessments of the sea-breeze transition times and results from a previously published subjective evaluation. The algorithm correctly identified a forecast or observed sea-breeze occurrence</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2008SPIE.6929E..26M','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2008SPIE.6929E..26M"><span id="translatedtitle">Development of a <span class="hlt">meso-scale</span> thermo-magneto-mechanical free energy <span class="hlt">model</span> for NiMnGa</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Morrison, Phillip; Seelecke, Stefan; Krevet, Berthold; Kohl, Manfred</p> <p>2008-03-01</p> <p>This paper motivates a one-dimensional thermo-magneto-mechanical free energy <span class="hlt">model</span> for NiMnGa. Following a discussion of material behavior and <span class="hlt">modeling</span> purpose, we present what might be referred to as a <span class="hlt">meso-scale</span> <span class="hlt">model</span>, incorporating micro-scale physics while striving for macro-scale simplicity. Development of the <span class="hlt">model</span> begins with the construction of a free energy landscape for the material, with strain and magnetization as its order parameters. This landscape includes paraboloidal energy wells - isolated from each other by energy barriers - to represent stable states of the material. The energy well positions and barrier heights are allowed to vary as functions of stress, magnetic field, and temperature. The resulting equations are employed within the theory of thermally activated processes to find the phase-fraction evolution of a sample. Previous results demonstrating the potential of the <span class="hlt">modeling</span> approach are included.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2011BoLMe.138...77O','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2011BoLMe.138...77O"><span id="translatedtitle">Thermal Energy Balance Analysis of the Tokyo Metropolitan Area Using a <span class="hlt">Mesoscale</span> Meteorological <span class="hlt">Model</span> Incorporating an Urban Canopy <span class="hlt">Model</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Ooka, Ryozo; Sato, Taiki; Harayama, Kazuya; Murakami, Shuzo; Kawamoto, Yoichi</p> <p>2011-01-01</p> <p>The summer climate around the Tokyo metropolitan area has been analysed on an urban scale, and the regional characteristics of the thermal energy balance of a bayside business district in the centre of Tokyo (Otemachi) have been compared with an inland residential district (Nerima), using a <span class="hlt">mesoscale</span> meteorological <span class="hlt">model</span> incorporating an urban canopy <span class="hlt">model</span>. From the results of the analysis, the mechanism of diurnal change in air temperature and absolute humidity in these areas is quantitatively demonstrated, with a focus on the thermal energy balance. Moreover, effective countermeasures against urban heat-islands are considered from the viewpoint of each region's thermal energy balance characteristics. In addition to thermal energy outflux by turbulent diffusion, advection by sea-breezes from Tokyo Bay discharges sensible heat in Otemachi. This mitigates temperature increases during the day. On the other hand, because all sea-breezes must first cross the centre of Tokyo, it has less of a cooling effect in Nerima. As a result, the air temperature during the day in Nerima is higher than that in Otemachi.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2011AGUFMEP41C0625K','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2011AGUFMEP41C0625K"><span id="translatedtitle">LAPSUS-D: testing a new daily sediment delivery <span class="hlt">model</span> in a <span class="hlt">meso-scale</span> Mediterranean catchment in Northern Israel</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Keesstra, S.; Temme, A.; Wittenberg, L.; Greenbaum, N.</p> <p>2011-12-01</p> <p>LAPSUS-D is a new sediment delivery <span class="hlt">model</span> that simulates sediment and water discharge at the temporal scale of one day and the spatial scale of a <span class="hlt">meso-scale</span> catchment, using only generally available data, such as a DEM, a soil map, a land use map, daily discharge and precipitation data and a general idea of the soil depths in the catchment. The landscape evolution <span class="hlt">model</span> LAPSUS (Schoorl, 2002) was adapted to <span class="hlt">model</span> sediment yield on a daily basis instead of the original annual basis. LAPSUS-D uses the water balance per cell and for the entire catchment to calculate water and sediment transport and this feature enables calibration with measured daily discharge at the outlet. With this information the <span class="hlt">model</span> can be calibrated for the water flow part which will give a good indication of the possibilities for sediment transport. First testing of the <span class="hlt">model</span> in catchments with a temperate climate in SW Poland and SE Germany showed that the <span class="hlt">model</span> is able to postdict the daily outflow well, when focusing on peak discharge characteristics. These hydrological features are the main determining factor for the generation of sediment outflow, and therefore most important to be able predict sediment delivery in a catchment well. In a Mediterranean catchment in Israel, Nahal Oren, the <span class="hlt">model</span> was tested for this new climate setting. Moreover, the first testing of the <span class="hlt">models</span> sediment module was conducted. This indicated that the <span class="hlt">model</span> post-dicts the sediment yield within the right order of magnitude and has potential to function as a tool for catchment managers. Keywords: LAPSUS-D, daily sediment yield <span class="hlt">model</span>, <span class="hlt">meso-scale</span> catchment, Mediterranean climate, Nahal Oren, Israel</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2008AGUFMOS41A1204C','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2008AGUFMOS41A1204C"><span id="translatedtitle">Investigation of Northeastern North America Coastal Circulation Using a <span class="hlt">Nested</span> Regional Circulation Hindcast <span class="hlt">Model</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Chen, K.; He, R.</p> <p>2008-12-01</p> <p>A regional coastal circulation <span class="hlt">model</span> was used to hindcast circulation over the middle Atlantic Bight (MAB) and Gulf of Maine (GOM) shelf from November 2003 to June 2008. Realistic atmospheric forcing, tidal harmonics and real-time river runoff data were used to drive the hindcast. In addition, this regional <span class="hlt">model</span> was <span class="hlt">nested</span> inside the data assimilative global HYCOM, which provides dynamically consistent and numerically accurate its initial and open boundary conditions. <span class="hlt">Model</span> hindcast solutions were gauged against in situ observations, including coastal sea levels, satellite altimeter sea surface height, mooring observed temperature and salinity time series, glider hydrographic transects, and long term means of depth-averaged current analysis. Such data/<span class="hlt">model</span> comparisons show the <span class="hlt">nested</span> regional <span class="hlt">model</span> is skillful in capturing major regional shelf circulation variability, lending confidence for using 4-year of time and space continuous hindcast fields (January 2004-December 2007) to depict shelf- wide circulation dynamics, along- and cross-shelf transport and the associated momentum balances. <span class="hlt">Model</span> hindcast solutions confirm the existence of the equatorward shelf circulation with gradually decreased alongshore transport from north to south. Mean alongshelf current is characterized by a strong shelf-break jet, whereas the cross-shelf current is characterized by complex convergence and divergence on the shelf. Mean cross-shelf transports were estimated along 200-m isobath. Momentum balance analyses further nonlinear advection, stress and diffusion term all contribute to the ageostrophic circulation in the along- isobath directions, whereas in the across-isobath direction, the nonlinear advection is predominate. Our <span class="hlt">nested</span> regional circulation <span class="hlt">model</span> was also coupled with a 11-component ecosystem <span class="hlt">model</span>. Some preliminary bio-physical <span class="hlt">modeling</span> result will also be presented.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/servlets/purl/940149','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/servlets/purl/940149"><span id="translatedtitle"><span class="hlt">Mesoscale</span> <span class="hlt">modeling</span> of irreversible volume growth in powders of anisotropic crystals</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Gee, R; Maiti, A; Fried, L</p> <p>2006-05-05</p> <p>Careful thermometric analysis (TMA) on powders of micron-sized triamino-trinitrobenzene (TATB) crystallites are shown to display irreversible growth in volume when subjected to repeated cycles of heating and cooling. Such behavior is counter-intuitive to typical materials response to simulated annealing cycles in atomic-scale molecular dynamics. However, through coarse-grained simulations using a <span class="hlt">mesoscale</span> Hamiltonian we quantitatively reproduce irreversible growth behavior in such powdered material. We demonstrate that irreversible growth happens only in the presence of intrinsic crystalline anisotropy, and is mediated by particles much smaller than the average crystallite size.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015EGUGA..1712530K','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015EGUGA..1712530K"><span id="translatedtitle">Wind Power Energy in Southern Brazil: evaluation using a <span class="hlt">mesoscale</span> meteorological <span class="hlt">model</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Krusche, Nisia; Stoevesandt, Bernhard; Chang, Chi-Yao; Peralta, Carlos</p> <p>2015-04-01</p> <p>In recent years, several wind farms were build in the coast of Rio Grande do Sul state. This region of Brazil was identified, in wind energy studies, as most favorable to the development of wind power energy, along with the Northeast part of the country. Site assessments of wind power, over long periods to estimate the power production and forecasts over short periods can be used for planning of power distribution and enhancements on Brazil's present capacity to use this resource. The computational power available today allows the simulation of the atmospheric flow in great detail. For instance, one of the authors participated in a research that demonstrated the interaction between the lake and maritime breeze in this region through the use of a atmospheric <span class="hlt">model</span>. Therefore, we aim to evaluate simulations of wind conditions and its potential to generate energy in this region. The <span class="hlt">model</span> applied is the Weather Research and Forecasting , which is the <span class="hlt">mesoscale</span> weather forecast software. The calculation domain is centered in 32oS and 52oW, in the southern region of Rio Grande do Sul state. The initial conditions of the simulation are taken from the global weather forecast in the time period from October 1st to October 31st, 2006. The wind power potential was calculated for a generic turbine, with a blade length of 52 m, using the expression: P=1/2*d*A*Cp*v^3, where P is the wind power energy (in Watts), d is the density (equal to 1.23 kg/m^3), A is the area section, which is equal to 8500 m2 , and v is the intensity of the velocity. The evaluation was done for a turbine placed at 50 m and 150 m of height. A threshold was chosen for a turbine production of 1.5 MW to estimate the potential of the site. In contrast to northern Brazilian region, which has a rather constant wind condition, this region shows a great variation of power output due to the weather variability. During the period of the study, at least three frontal systems went over the region, and thre was a</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015JHyd..529..696G','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015JHyd..529..696G"><span id="translatedtitle">Re-evaluation of moisture sources for the August 2002 extreme rainfall episode in central Europe: Evaporation from falling precipitation included in a <span class="hlt">mesoscale</span> <span class="hlt">modeling</span> system</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Gangoiti, G.; Sáez de Cámara, E.; Gómez-Domenech, I.; Alonso, L.; Navazo, M.; Iza, J.; García, J. A.; Millán, M. M.</p> <p>2015-10-01</p> <p>Discriminating moisture sources with precision is an important requirement to better understand the processes involved in extreme rainfall episodes. In a previous contribution by Gangoiti et al. (2011b), an innovative technique was presented to assess surface moisture sources contributing to a target precipitation within a Lagrangian framework. The technique was based in transporting parcels of vapor, representing the target precipitation, across a set of <span class="hlt">nested</span> grids covering a large area at different resolutions. A <span class="hlt">mesoscale</span> <span class="hlt">model</span> estimated the meteorological variables to transport and redistribute the vapor back into its original sources, all of them assumed to be at the surface. The sequence of extreme rainfall events, which occurred over central Europe on August 11-13, 2002, was chosen to put the methodology to test. An important innovation has now been introduced. This new advance allows discriminating not only the terrestrial and oceanic sources but also the evaporation from precipitation occurring below the clouds and falling either on land or on the open sea. It is also able to detect with greater precision the relative importance of remote versus local sources, together with the sequence of evaporation of a rainfall event. After its application to the same episode and targets, our results confirm a similar distribution and strength of surface terrestrial and marine sources. Furthermore, the estimated direct evaporation from precipitation columns contributes to the precipitation episode with a significant amount of moisture which averages around 18% of the total sources, with a main fraction evaporated over land and close to the target regions in central Europe. This contribution adds to the surface sources, and it is consistent with the existence of an important mechanism of positive feedback for the inland transport efficiency of moisture and precipitation, operating at the regional level for this type of episodes. Significant regional differences are</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://ntrs.nasa.gov/search.jsp?R=19850054706&hterms=effect+assimilation&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D60%26Ntt%3Deffect%2Bassimilation','NASA-TRS'); return false;" href="http://ntrs.nasa.gov/search.jsp?R=19850054706&hterms=effect+assimilation&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D60%26Ntt%3Deffect%2Bassimilation"><span id="translatedtitle">Variational assimilation of VAS data into a <span class="hlt">mesoscale</span> <span class="hlt">model</span> Assimilation method and sensitivity experiments. [Visible Infrared Spin-Scan Radiometer Atmospheric Sounder</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Cram, J. M.; Kaplan, M. L.</p> <p>1985-01-01</p> <p>The assimilation of temperature and moisture gradient information from the Visible IR Spin-Scan Radiometer's Atmospheric Sounder (VAS) into a <span class="hlt">mesoscale</span> <span class="hlt">model</span> is presently undertaken by means of a variational method and followed by tests of the sensitivity of both diabatic and adiabatic versions of the <span class="hlt">model</span> to VAS data assimilations for the case of July 20-21, 1981. The synoptic scale effects of the assimilation of VAS data are noted to be negligible; the greatest impact was instead on <span class="hlt">mesoscale</span> forecasts of convective instability patterns. The additional assimilation of relative humidity gradients did not significantly change the patterns of the forecast instabilities. The greatest improvements from assimilation resulted from the resolution of the strong <span class="hlt">mesoscale</span> temperature gradients by the asynoptic VAS data.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2011JGRD..11618105S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2011JGRD..11618105S"><span id="translatedtitle"><span class="hlt">Modeling</span> the water isotopes in Greenland precipitation 1959-2001 with the <span class="hlt">meso-scale</span> <span class="hlt">model</span> REMO-iso</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Sjolte, J.; Hoffmann, G.; Johnsen, S. J.; Vinther, B. M.; Masson-Delmotte, V.; Sturm, C.</p> <p>2011-09-01</p> <p>Ice core studies have proved the δ18O in Greenland precipitation to be correlated to the phase of the North Atlantic Oscillation (NAO). This subject has also been investigated in <span class="hlt">modeling</span> studies. However, these studies have either had severe biases in the δ18O levels, or have not been designed to be compared directly with observations. In this study we nudge a <span class="hlt">meso-scale</span> climate <span class="hlt">model</span> fitted with stable water isotope diagnostics (REMO-iso) to follow the actual weather patterns for the period 1959-2001. We evaluate this simulation using meteorological observations from stations along the Greenland coast, and δ18O from several Greenland ice core stacks and Global Network In Precipitation (GNIP) data from Greenland, Iceland and Svalbard. The REMO-iso output explains up to 40% of the interannual δ18O variability observed in ice cores, which is comparable to the <span class="hlt">model</span> performance for precipitation. In terms of reproducing the observed variability the global <span class="hlt">model</span>, ECHAM4-iso performs on the same level as REMO-iso. However, REMO-iso has smaller biases in δ18O and improved representation of the observed spatial δ18O-temperature slope compared to ECHAM4-iso. Analysis of the main modes of winter variability of δ18O shows a coherent signal in Central and Western Greenland similar to results from ice cores. The NAO explains 20% of the leading δ18O pattern. Based on the <span class="hlt">model</span> output we suggest that methods to reconstruct the NAO from Greenland ice cores employ both δ18O and accumulation records.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://cfpub.epa.gov/si/si_public_record_report.cfm?dirEntryId=47155&keyword=cloud+AND+computing&actType=&TIMSType=+&TIMSSubTypeID=&DEID=&epaNumber=&ntisID=&archiveStatus=Both&ombCat=Any&dateBeginCreated=&dateEndCreated=&dateBeginPublishedPresented=&dateEndPublishedPresented=&dateBeginUpdated=&dateEndUpdated=&dateBeginCompleted=&dateEndCompleted=&personID=&role=Any&journalID=&publisherID=&sortBy=revisionDate&count=50&CFID=77092225&CFTOKEN=60714670','EPA-EIMS'); return false;" href="http://cfpub.epa.gov/si/si_public_record_report.cfm?dirEntryId=47155&keyword=cloud+AND+computing&actType=&TIMSType=+&TIMSSubTypeID=&DEID=&epaNumber=&ntisID=&archiveStatus=Both&ombCat=Any&dateBeginCreated=&dateEndCreated=&dateBeginPublishedPresented=&dateEndPublishedPresented=&dateBeginUpdated=&dateEndUpdated=&dateBeginCompleted=&dateEndCompleted=&personID=&role=Any&journalID=&publisherID=&sortBy=revisionDate&count=50&CFID=77092225&CFTOKEN=60714670"><span id="translatedtitle"><span class="hlt">MODELED</span> <span class="hlt">MESOSCALE</span> METEOROLOGICAL FIELDS WITH FOUR-DIMENSIONAL DATA ASSIMILATION IN REGIONAL SCALE AIR QUALITY <span class="hlt">MODELS</span></span></a></p> <p><a target="_blank" href="http://oaspub.epa.gov/eims/query.page">EPA Science Inventory</a></p> <p></p> <p></p> <p>This paper addresses the need to increase the temporal and spatial resolution of meteorological data currently used in air quality simulation <span class="hlt">models</span>, AQSMs. ransport and diffusion parameters including mixing heights and stability used in regulatory air quality dispersion <span class="hlt">models</span> a...</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://ntrs.nasa.gov/search.jsp?R=20020051129&hterms=diabetic&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D30%26Ntt%3Ddiabetic','NASA-TRS'); return false;" href="http://ntrs.nasa.gov/search.jsp?R=20020051129&hterms=diabetic&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D30%26Ntt%3Ddiabetic"><span id="translatedtitle">Evidence of Stratosphere-to-Troposphere Transport Within a <span class="hlt">Mesoscale</span> <span class="hlt">Model</span> and Total Ozone Mapping Spectrometer Total Ozone</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Olsen, Mark A.; Stanford, John L.</p> <p>2001-01-01</p> <p>We evaluate evidence for stratospheric mass transport into, and mass remaining in, the troposphere during an intense midlatitude cyclone. <span class="hlt">Mesoscale</span> forecast <span class="hlt">model</span> analysis fields from the <span class="hlt">Mesoscale</span> Analysis and Prediction System were matched with total ozone observations from the Total Ozone Measurement Spectrometer. Combined with parcel back trajectory calculations, the analyses imply that two mechanisms contributed to the mass exchange: (1) An area of dynamically induced exchange was observed on the cyclone's southern edge. Parcels originally in the stratosphere crossed the jet core and were diluted through turbulent mixing with tropospheric air; (2) Diabetic effects reduced parcel potential vorticity (PC) for trajectories traversing precipitation regions, creating a 'PV hole' signature in the center of the cyclone. Air with characteristics of ozone and water vapor found in the lower stratosphere remained in the troposphere. The strength of the latter process may be unusual. Combined with other research, these results suggest that precipitation-induced diabetic effects can significantly modify (either decreasing or increasing) parcel potential vorticity, depending on parcel trajectory configuration with respect to maximum heating regions and jet core. The diabetic heating effect on stratosphere-troposphere exchange (STE) is more important to tropopause erosion than to altering parcel trajectories. In addition, these results underline the importance of using not only PC but also chemical constituents for diagnoses of STE.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2010JMEP...19...22G','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2010JMEP...19...22G"><span id="translatedtitle">Development of a <span class="hlt">Meso-Scale</span> Material <span class="hlt">Model</span> for Ballistic Fabric and Its Use in Flexible-Armor Protection Systems</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Grujicic, M.; Bell, W. C.; Arakere, G.; He, T.; Xie, X.; Cheeseman, B. A.</p> <p>2010-02-01</p> <p>A <span class="hlt">meso-scale</span> ballistic material <span class="hlt">model</span> for a prototypical plain-woven single-ply flexible armor is developed and implemented in a material user subroutine for the use in commercial explicit finite element programs. The main intent of the <span class="hlt">model</span> is to attain computational efficiency when calculating the mechanical response of the multi-ply fabric-based flexible-armor material during its impact with various projectiles without significantly sacrificing the key physical aspects of the fabric microstructure, architecture, and behavior. To validate the new <span class="hlt">model</span>, a comparative finite element method analysis is carried out in which: (a) the plain-woven single-ply fabric is <span class="hlt">modeled</span> using conventional shell elements and weaving is done in an explicit manner by snaking the yarns through the fabric and (b) the fabric is treated as a planar continuum surface composed of conventional shell elements to which the new <span class="hlt">meso-scale</span> unit-cell based material <span class="hlt">model</span> is assigned. The results obtained show that the material <span class="hlt">model</span> provides a reasonably good description for the fabric deformation and fracture behavior under different combinations of fixed and free boundary conditions. Finally, the <span class="hlt">model</span> is used in an investigation of the ability of a multi-ply soft-body armor vest to protect the wearer from impact by a 9-mm round nose projectile. The effects of inter-ply friction, projectile/yarn friction, and the far-field boundary conditions are revealed and the results explained using simple wave mechanics principles, high-deformation rate material behavior, and the role of various energy-absorbing mechanisms in the fabric-based armor systems.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://ntrs.nasa.gov/search.jsp?R=20020020656&hterms=Statistics&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D70%26Ntt%3DStatistics','NASA-TRS'); return false;" href="http://ntrs.nasa.gov/search.jsp?R=20020020656&hterms=Statistics&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D70%26Ntt%3DStatistics"><span id="translatedtitle">Estimation of <span class="hlt">Mesoscale</span> Atmospheric Latent Heating Profiles from TRMM Rain Statistics Utilizing a Simple One-Dimensional <span class="hlt">Model</span></span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Iacovazzi, Robert A., Jr.; Prabhakara, C.; Lau, William K. M. (Technical Monitor)</p> <p>2001-01-01</p> <p>In this study, a <span class="hlt">model</span> is developed to estimate <span class="hlt">mesoscale</span>-resolution atmospheric latent heating (ALH) profiles. It utilizes rain statistics deduced from Tropical Rainfall Measuring Mission (TRMM) data, and cloud vertical velocity profiles and regional surface thermodynamic climatologies derived from other available data sources. From several rain events observed over tropical ocean and land, ALH profiles retrieved by this <span class="hlt">model</span> in convective rain regions reveal strong warming throughout most of the troposphere, while in stratiform rain regions they usually show slight cooling below the freezing level and significant warming above. The <span class="hlt">mesoscale</span>-average, or total, ALH profiles reveal a dominant stratiform character, because stratiform rain areas are usually much larger than convective rain areas. Sensitivity tests of the <span class="hlt">model</span> show that total ALH at a given tropospheric level varies by less than +/- 10 % when convective and stratiform rain rates and <span class="hlt">mesoscale</span> fractional rain areas are perturbed individually by 1 15 %. This is also found when the non-uniform convective vertical velocity profiles are replaced by one that is uniform. Larger variability of the total ALH profiles arises when climatological ocean- and land-surface temperatures (water vapor mixing ratios) are independently perturbed by +/- 1.0 K (+/- 5 %) and +/- 5.0 K (+/- 15 %), respectively. At a given tropospheric level, such perturbations can cause a +/- 25 % variation of total ALH over ocean, and a factor-of-two sensitivity over land. This sensitivity is reduced substantially if perturbations of surface thermodynamic variables do not change surface relative humidity, or are not extended throughout the entire <span class="hlt">model</span> evaporation layer. The ALH profiles retrieved in this study agree qualitatively with tropical total diabatic heating profiles deduced in earlier studies. Also, from January and July 1999 ALH-profile climatologies generated separately with TRMM Microwave Imager and Precipitation Radar rain</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015GMD.....8.3715V','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015GMD.....8.3715V"><span id="translatedtitle">The Explicit Wake Parametrisation V1.0: a wind farm parametrisation in the <span class="hlt">mesoscale</span> <span class="hlt">model</span> WRF</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Volker, P. J. H.; Badger, J.; Hahmann, A. N.; Ott, S.</p> <p>2015-11-01</p> <p>We describe the theoretical basis, implementation, and validation of a new parametrisation that accounts for the effect of large offshore wind farms on the atmosphere and can be used in <span class="hlt">mesoscale</span> and large-scale atmospheric <span class="hlt">models</span>. This new parametrisation, referred to as the Explicit Wake Parametrisation (EWP), uses classical wake theory to describe the unresolved wake expansion. The EWP scheme is validated for a neutral atmospheric boundary layer against filtered in situ measurements from two meteorological masts situated a few kilometres away from the Danish offshore wind farm Horns Rev I. The simulated velocity deficit in the wake of the wind farm compares well to that observed in the measurements, and the velocity profile is qualitatively similar to that simulated with large eddy simulation <span class="hlt">models</span> and from wind tunnel studies. At the same time, the validation process highlights the challenges in verifying such <span class="hlt">models</span> with real observations.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015GMDD....8.3481V','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015GMDD....8.3481V"><span id="translatedtitle">The Explicit Wake Parametrisation V1.0: a wind farm parametrisation in the <span class="hlt">mesoscale</span> <span class="hlt">model</span> WRF</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Volker, P. J. H.; Badger, J.; Hahmann, A. N.; Ott, S.</p> <p>2015-04-01</p> <p>We describe the theoretical basis, implementation and validation of a new parametrisation that accounts for the effect of large offshore wind farms on the atmosphere and can be used in <span class="hlt">mesoscale</span> and large-scale atmospheric <span class="hlt">models</span>. This new parametrisation, referred to as the Explicit Wake Parametrisation (EWP), uses classical wake theory to describe the unresolved wake expansion. The EWP scheme is validated against filtered in situ measurements from two meteorological masts situated a few kilometres away from the Danish offshore wind farm Horns Rev I. The simulated velocity deficit in the wake of the wind farm compares well to that observed in the measurements and the velocity profile is qualitatively similar to that simulated with large eddy simulation <span class="hlt">models</span> and from wind tunnel studies. At the same time, the validation process highlights the challenges in verifying such <span class="hlt">models</span> with real observations.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2001PhDT........21K','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2001PhDT........21K"><span id="translatedtitle">The development and implementation of a <span class="hlt">mesoscale</span> <span class="hlt">modeling</span> system for simulating the meteorology and air quality situation in the Mae Moh Valley</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Kowalewsky, Karen Jean</p> <p>2001-08-01</p> <p>The Mae Moh Valley region of northern Thailand experiences frequent pollutant fumigation events during the annual cool season. The onset and magnitude of these events are driven by the synoptic scale and <span class="hlt">mesoscale</span> conditions that develop over the Valley during the cool season. A conclusion from previous studies conducted in the Valley was that to properly predict the onset and magnitude of the fumigation events, a three dimensional wind field generated using a <span class="hlt">mesoscale</span> meteorological <span class="hlt">model</span> needed to be used in a <span class="hlt">mesoscale</span> transport and dispersion <span class="hlt">model</span>. The results of the previous studies led to the <span class="hlt">modeling</span> analysis presented in this dissertation. The research hypothesis was that it would be possible to develop a <span class="hlt">mesoscale</span> dispersion <span class="hlt">modeling</span> system that could simulate the Valley fumigation events. The null hypothesis was that the air dispersion <span class="hlt">modeling</span> system could not simulate the fumigation events. The Penn State/NCAR <span class="hlt">Mesoscale</span> Meteorological <span class="hlt">Model</span>, Version 5 (MM5) was used to generate the <span class="hlt">mesoscale</span> meteorological parameters used as input to the United States Environmental Protection Agency (USEPA) CALMET/CALPUFF <span class="hlt">mesoscale</span> dispersion and transport <span class="hlt">model</span>. These <span class="hlt">models</span> were used to forecast one fumigation event observed in 1997. Three <span class="hlt">model</span> scenarios were considered for the fumigation event. The differences in the <span class="hlt">model</span> scenarios were a function of modifications to terrain and horizontal and vertical grid resolutions used by MM5. Output from the combined MM5/CALMET/CALPUFF was compared with observations to document the <span class="hlt">modeling</span> system's strengths and limitations. The results from this study indicated that MM5 appeared to be capable of simulating the temperature profile required to produce a fumigation event in the Valley. However, due to errors in the input meteorological data, MM5 was not capable of forecasting the light and variable wind conditions present within the Valley prior to and during the fumigation events. These wind field errors contributed to</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3735395','PMC'); return false;" href="http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3735395"><span id="translatedtitle"><span class="hlt">Nested</span> sampling for parameter inference in systems biology: application to an exemplar circadian <span class="hlt">model</span></span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p></p> <p>2013-01-01</p> <p>Background <span class="hlt">Model</span> selection and parameter inference are complex problems that have yet to be fully addressed in systems biology. In contrast with parameter optimisation, parameter inference computes both the parameter means and their standard deviations (or full posterior distributions), thus yielding important information on the extent to which the data and the <span class="hlt">model</span> topology constrain the inferred parameter values. Results We report on the application of <span class="hlt">nested</span> sampling, a statistical approach to computing the Bayesian evidence Z, to the inference of parameters, and the estimation of log Z in an established <span class="hlt">model</span> of circadian rhythms. A ten-fold difference in the coefficient of variation between degradation and transcription parameters is demonstrated. We further show that the uncertainty remaining in the parameter values is reduced by the analysis of increasing numbers of circadian cycles of data, up to 4 cycles, but is unaffected by sampling the data more frequently. Novel algorithms for calculating the likelihood of a <span class="hlt">model</span>, and a characterisation of the performance of the <span class="hlt">nested</span> sampling algorithm are also reported. The methods we develop considerably improve the computational efficiency of the likelihood calculation, and of the exploratory step within <span class="hlt">nested</span> sampling. Conclusions We have demonstrated in an exemplar circadian <span class="hlt">model</span> that the estimates of posterior parameter densities (as summarised by parameter means and standard deviations) are influenced predominately by the length of the time series, becoming more narrowly constrained as the number of circadian cycles considered increases. We have also shown the utility of the coefficient of variation for discriminating between highly-constrained and less-well constrained parameters. PMID:23899119</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/1993GeoRL..20.2897S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/1993GeoRL..20.2897S"><span id="translatedtitle">A <span class="hlt">nested</span> <span class="hlt">model</span> study of the Sahelian climate response to sea-surface temperature anomalies</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Semazzi, Fredrick H. M.; Lin, Neng-Huei; Lin, Yuh-Lang; Giorgi, Filippo</p> <p>1993-12-01</p> <p>A <span class="hlt">nested</span> high resolution atmospheric <span class="hlt">model</span> is used to investigate the sensitivity of the Sahelian climate to large-scale sea-surface temperature (SST) anomalies. The <span class="hlt">nested</span> system has realistic vegetation and detailed bottom orography. Two separate sets of northern hemispheric summer (June, July and August) numerical integrations are performed; one corresponding to the SST anomalies in 1950 when the Sahelian region was relatively much wetter than the long-term average conditions and a second integration based on 1984 SST anomalies when one of the driest rain seasons in the last few decades was experienced. Although the low resolution (R15 ≈ 4.5° by 7.5° latitude by longitude) stand-alone global climate <span class="hlt">model</span> reasonably simulates the lower rainfall amounts in 1984 compared to 1950, the <span class="hlt">nested</span> system yields more realistic regional climate because its forcing includes more detailed effects of topography, land-sea contrasts, and land surface processes. In particular, two distinct rainfall maxima primarily anchored to the regions of highest terrain are simulated by the <span class="hlt">model</span>. One corresponding to the highlands in Cameroon over the Adamawa Plateau and a second maxima over Guinea and Sierra-Leone. Inspection of <span class="hlt">model</span> circulation indicates that the weaker moist cross-equatorial monsoon flow in the 1984 is responsible for the lower amounts of the Sahelian rainfall compared to 1950. Our results are in agreement with several diagnostic and <span class="hlt">modeling</span> studies performed in the recent years which show that deficient sub-Saharan rainy seasons tends to coincide with the southwesterly surface monsoon flow not extending as far north along the West African coast as in the wetter years (Lamb and Peppier, 1990, and others).</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_16");'>16</a></li> <li><a href="#" onclick='return showDiv("page_17");'>17</a></li> <li class="active"><span>18</span></li> <li><a href="#" onclick='return showDiv("page_19");'>19</a></li> <li><a href="#" onclick='return showDiv("page_20");'>20</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_18 --> <div id="page_19" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_17");'>17</a></li> <li><a href="#" onclick='return showDiv("page_18");'>18</a></li> <li class="active"><span>19</span></li> <li><a href="#" onclick='return showDiv("page_20");'>20</a></li> <li><a href="#" onclick='return showDiv("page_21");'>21</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="361"> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015EGUGA..1714285S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015EGUGA..1714285S"><span id="translatedtitle">Performance of MODIS satellite and <span class="hlt">mesoscale</span> <span class="hlt">model</span> based land surface temperature for soil moisture deficit estimation using Neural Network</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Srivastava, Prashant K.; Petropoulos, George P.; Gupta, Manika; Islam, Tanvir</p> <p>2015-04-01</p> <p>Soil Moisture Deficit (SMD) is a key variable in the water and energy exchanges that occur at the land-surface/atmosphere interface. Monitoring SMD is an alternate method of irrigation scheduling and represents the use of the suitable quantity of water at the proper time by combining measurements of soil moisture deficit. In past it is found that LST has a strong relation to SMD, which can be estimated by MODIS or numerical weather prediction <span class="hlt">model</span> such as WRF (Weather Research and Forecasting <span class="hlt">model</span>). By looking into the importance of SMD, this work focused on the application of Artificial Neural Network (ANN) for evaluating its capabilities towards SMD estimation using the LST data estimated from MODIS and WRF <span class="hlt">mesoscale</span> <span class="hlt">model</span>. The benchmark SMD estimated from Probability Distribution <span class="hlt">Model</span> (PDM) over the Brue catchment, Southwest of England, U.K. is used for all the calibration and validation experiments. The performances between observed and simulated SMD are assessed in terms of the Nash-Sutcliffe Efficiency (NSE), the Root Mean Square Error (RMSE) and the percentage of bias (%Bias). The application of the ANN confirmed a high capability WRF and MODIS LST for prediction of SMD. Performance during the ANN calibration and validation showed a good agreement between benchmark and estimated SMD with MODIS LST information with significantly higher performance than WRF simulated LST. The work presented showed the first comprehensive application of LST from MODIS and WRF <span class="hlt">mesoscale</span> <span class="hlt">model</span> for hydrological SMD estimation, particularly for the maritime climate. More studies in this direction are recommended to hydro-meteorological community, so that useful information will be accumulated in the technical literature domain for different geographical locations and climatic conditions. Keyword: WRF, Land Surface Temperature, MODIS satellite, Soil Moisture Deficit, Neural Network</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/servlets/purl/10119533','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/servlets/purl/10119533"><span id="translatedtitle">An approach for parameterizing <span class="hlt">mesoscale</span> precipitating systems</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Weissbluth, M.J.; Cotton, W.R.</p> <p>1991-12-31</p> <p>A cumulus parameterization laboratory has been described which uses a reference numerical <span class="hlt">model</span> to fabricate, calibrate and verify a cumulus parameterization scheme suitable for use in <span class="hlt">mesoscale</span> <span class="hlt">models</span>. Key features of this scheme include resolution independence and the ability to provide hydrometeor source functions to the host <span class="hlt">model</span>. Thus far, only convective scale drafts have been parameterized, limiting the use of the scheme to those <span class="hlt">models</span> which can resolve the <span class="hlt">mesoscale</span> circulations. As it stands, the scheme could probably be incorporated into <span class="hlt">models</span> having a grid resolution greater than 50 km with results comparable to the existing schemes for the large-scale <span class="hlt">models</span>. We propose, however, to quantify the <span class="hlt">mesoscale</span> circulations through the use of the cumulus parameterization laboratory. The inclusion of these <span class="hlt">mesoscale</span> drafts in the existing scheme will hopefully allow the correct parameterization of the organized <span class="hlt">mesoscale</span> precipitating systems.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/servlets/purl/5750068','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/servlets/purl/5750068"><span id="translatedtitle">An approach for parameterizing <span class="hlt">mesoscale</span> precipitating systems</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Weissbluth, M.J.; Cotton, W.R.</p> <p>1991-01-01</p> <p>A cumulus parameterization laboratory has been described which uses a reference numerical <span class="hlt">model</span> to fabricate, calibrate and verify a cumulus parameterization scheme suitable for use in <span class="hlt">mesoscale</span> <span class="hlt">models</span>. Key features of this scheme include resolution independence and the ability to provide hydrometeor source functions to the host <span class="hlt">model</span>. Thus far, only convective scale drafts have been parameterized, limiting the use of the scheme to those <span class="hlt">models</span> which can resolve the <span class="hlt">mesoscale</span> circulations. As it stands, the scheme could probably be incorporated into <span class="hlt">models</span> having a grid resolution greater than 50 km with results comparable to the existing schemes for the large-scale <span class="hlt">models</span>. We propose, however, to quantify the <span class="hlt">mesoscale</span> circulations through the use of the cumulus parameterization laboratory. The inclusion of these <span class="hlt">mesoscale</span> drafts in the existing scheme will hopefully allow the correct parameterization of the organized <span class="hlt">mesoscale</span> precipitating systems.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://ntrs.nasa.gov/search.jsp?R=20020061382&hterms=Model&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DTitle%26N%3D0%26No%3D70%26Ntt%3DModel','NASA-TRS'); return false;" href="http://ntrs.nasa.gov/search.jsp?R=20020061382&hterms=Model&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DTitle%26N%3D0%26No%3D70%26Ntt%3DModel"><span id="translatedtitle"><span class="hlt">Mesoscale</span> Convective Systems in SCSMEX: Simulated by a Regional Climate <span class="hlt">Model</span> and a Cloud Resolving <span class="hlt">Model</span></span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Tao, W.-K.; Wang, Y.; Qian, I.; Lau, W.; Shie, C.-L.; Starr, David (Technical Monitor)</p> <p>2002-01-01</p> <p>A Regional Land-Atmosphere Climate Simulation (RELACS) System is being developed and implemented at NASA Goddard Space Flight Center. One of the major goals of RELACS is to use a regional scale <span class="hlt">model</span> with improved physical processes, in particular land-related processes, to understand the role of the land surface and its interaction with convection and radiation as well as the water and energy cycles in Indo-China/ South China Sea (SCS)/China, N. America and S. America. The Penn State/NCAR MM5 atmospheric <span class="hlt">modeling</span> system, a state of the art atmospheric numerical <span class="hlt">model</span> designed to simulate regional weather and climate, has been successfully coupled to the Goddard Parameterization for Land-Atmosphere-C loud Exchange (PLACE) land surface <span class="hlt">model</span>. PLACE allows for the effects of vegetation, and thus important physical processes such as evapotranspiration and interception are included. The PLACE <span class="hlt">model</span> incorporates vegetation type and has been shown in international comparisons to accurately predict evapotranspiration and runoff over a wide variety of land surfaces. The coupling of MM5 and PLACE creates a numerical <span class="hlt">modeling</span> system with the potential to more realistically simulate the atmosphere and land surface processes including land-sea interaction, regional circulations such as monsoons, and flash flood events. RELACS has been used to simulate the onset of the South China Sea Monsoon in 1986, 1997 and 1998. Sensitivity tests on various land surface <span class="hlt">models</span>, cumulus parameterization schemes (CPSs), sea surface temperature (SST) variations and midlatitude influences have been performed. These tests have indicated that the land surface <span class="hlt">model</span> has a major impact on the circulation over the S. China Sea. CPSs can effect the precipitation pattern while SST variation can effect the precipitation amounts over both land and ocean. RELACS has also been used to understand the soil-precipitation interaction and feedback associated with a flood event that occurred in and around China</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://ntrs.nasa.gov/search.jsp?R=20010037685&hterms=Model&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DTitle%26N%3D0%26No%3D70%26Ntt%3DModel','NASA-TRS'); return false;" href="http://ntrs.nasa.gov/search.jsp?R=20010037685&hterms=Model&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DTitle%26N%3D0%26No%3D70%26Ntt%3DModel"><span id="translatedtitle"><span class="hlt">Mesoscale</span> Convective Systems in SCSMEX: Simulated by a Regional Climate <span class="hlt">Model</span> and a Cloud Resolving <span class="hlt">Model</span></span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Tao, W.-K.; Wang, Y.; Lau, W.; Jia, Y.; Johnson, D.; Shie, C.-L.; Einaudi, Franco (Technical Monitor)</p> <p>2001-01-01</p> <p>A Regional Land-Atmosphere Climate Simulation (RELACS) System is being developed and implemented at NASA Goddard Space Flight Center. One of the major goals of RELACS is to use a regional scale <span class="hlt">model</span> with improved physical processes, in particular land-related processes, to understand the role of the land surface and its interaction with convection and radiation as well as the water and energy cycles in Indo-China/South China Sea (SCS)/China, North America and South America. The Penn State/NCAR MM5 atmospheric <span class="hlt">modeling</span> system, a state of the art atmospheric numerical <span class="hlt">model</span> designed to simulate regional weather and climate, has been successfully coupled to the Goddard Parameterization for Land-Atmosphere-Cloud Exchange (PLACE) land surface <span class="hlt">model</span>, PLACE allows for the effect A vegetation, and thus important physical processes such as evapotranspiration and interception are included. The PLACE <span class="hlt">model</span> incorporates vegetation type and has been shown in international comparisons to accurately predict evapotranspiration and runoff over a wide variety of land surfaces. The coupling of MM5 and PLACE creates a numerical <span class="hlt">modeling</span> system with the potential to more realistically simulate the atmosphere and land surface processes including land-sea interaction, regional circulations such as monsoons, and flash flood events. RELACS has been used to simulate the onset of the South China Sea Monsoon in 1986, 1991 and 1998. Sensitivity tests on various land surface <span class="hlt">models</span>, cumulus parameterization schemes (CPSs), sea surface temperature (SST) variations and midlatitude influences have been performed. These tests have indicated that the land surface <span class="hlt">model</span> has a major impact on the circulation over the South China Sea. CPSs can effect the precipitation pattern while SST variation can effect the precipitation amounts over both land and ocean. RELACS has also been used to understand the soil-precipitation interaction and feedback associated with a flood event that occurred in and around</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2014PhyA..416..518G&link_type=ABSTRACT','NASAADS'); return false;" href="http://adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2014PhyA..416..518G&link_type=ABSTRACT"><span id="translatedtitle">A dual theory of price and value in a <span class="hlt">meso-scale</span> economic <span class="hlt">model</span> with stochastic profit rate</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Greenblatt, R. E.</p> <p>2014-12-01</p> <p>The problem of commodity price determination in a market-based, capitalist economy has a long and contentious history. Neoclassical microeconomic theories are based typically on marginal utility assumptions, while classical macroeconomic theories tend to be value-based. In the current work, I study a simplified <span class="hlt">meso-scale</span> <span class="hlt">model</span> of a commodity capitalist economy. The production/exchange <span class="hlt">model</span> is represented by a network whose nodes are firms, workers, capitalists, and markets, and whose directed edges represent physical or monetary flows. A pair of multivariate linear equations with stochastic input parameters represent physical (supply/demand) and monetary (income/expense) balance. The input parameters yield a non-degenerate profit rate distribution across firms. Labor time and price are found to be eigenvector solutions to the respective balance equations. A simple relation is derived relating the expected value of commodity price to commodity labor content. Results of Monte Carlo simulations are consistent with the stochastic price/labor content relation.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2013AGUFM.C53A0549E','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2013AGUFM.C53A0549E"><span id="translatedtitle">Toward Improved Parameterization of a <span class="hlt">Meso-Scale</span> Hydrologic <span class="hlt">Model</span> in a Discontinuous Permafrost, Boreal Forest Ecosystem</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Endalamaw, A. M.; Bolton, W. R.; Young, J. M.; Morton, D.; Hinzman, L. D.</p> <p>2013-12-01</p> <p>The sub-arctic environment can be characterized as being located in the zone of discontinuous permafrost. Although the distribution of permafrost is site specific, it dominates many of the hydrologic and ecologic responses and functions including vegetation distribution, stream flow, soil moisture, and storage processes. In this region, the boundaries that separate the major ecosystem types (deciduous dominated and coniferous dominated ecosystems) as well as permafrost (permafrost verses non-permafrost) occur over very short spatial scales. One of the goals of this research project is to improve parameterizations of <span class="hlt">meso-scale</span> hydrologic <span class="hlt">models</span> in this environment. Using the Caribou-Poker Creeks Research Watershed (CPCRW) as the test area, simulations of the headwater catchments of varying permafrost and vegetation distributions were performed. CPCRW, located approximately 50 km northeast of Fairbanks, Alaska, is located within the zone of discontinuous permafrost and the boreal forest ecosystem. The Variable Infiltration Capacity (VIC) <span class="hlt">model</span> was selected as the hydrologic <span class="hlt">model</span>. In CPCRW, permafrost and coniferous vegetation is generally found on north facing slopes and valley bottoms. Permafrost free soils and deciduous vegetation is generally found on south facing slopes. In this study, hydrologic simulations using fine scale vegetation and soil parameterizations - based upon slope and aspect analysis at a 50 meter resolution - were conducted. Simulations were also conducted using downscaled vegetation from the Scenarios Network for Alaska and Arctic Planning (SNAP) (1 km resolution) and soil data sets from the Food and Agriculture Organization (FAO) (approximately 9 km resolution). Preliminary simulation results show that soil and vegetation parameterizations based upon fine scale slope/aspect analysis increases the R2 values (0.5 to 0.65 in the high permafrost (53%) basin; 0.43 to 0.56 in the low permafrost (2%) basin) relative to parameterization based on</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/27154874','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/27154874"><span id="translatedtitle">Excessive <span class="hlt">nest</span> building is a unique behavioural phenotype in the deer mouse <span class="hlt">model</span> of obsessive-compulsive disorder.</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Wolmarans, De Wet; Stein, Dan J; Harvey, Brian H</p> <p>2016-09-01</p> <p>Obsessive-compulsive disorder (OCD) is a phenotypically heterogeneous condition characterised by time-consuming intrusive thoughts and/or compulsions. Irrespective of the symptom type diagnosed, the severity of OCD is characterised by heterogeneity in symptom presentation that complicates diagnosis and treatment. Heterogeneity of symptoms would be invaluable in an animal <span class="hlt">model</span>. <span class="hlt">Nest</span> building behaviour forms part of the normal behavioural repertoire of rodents and demonstrates profound between-species differences. However, it has been proposed that within-species differences in <span class="hlt">nest</span> building behaviour (i.e. aberrant vs. normal <span class="hlt">nest</span> building) may resemble obsessive-compulsive-like symptoms. In an attempt to investigate whether other obsessive-compulsive-like behaviours are present in an animal <span class="hlt">model</span> of OCD, or if aberrant <span class="hlt">nest</span> building behaviour may represent a unique obsessive-compulsive phenotype in such a <span class="hlt">model</span>, the current study assessed <span class="hlt">nest</span> building behaviour in high (H, viz obsessive-compulsive) and non (N, viz normal) stereotypical deer mice. Subsequently, 12 N and H animals, respectively, were provided with an excess of cotton wool daily for one week prior to and following four weeks of high-dose oral escitalopram treatment (50 mg/kg/day). Data from the current investigation demonstrate daily <span class="hlt">nesting</span> activity to be highly variable in deer mice, with stereotypy and <span class="hlt">nest</span> building being independent behaviours. However, we identified unique aberrant large <span class="hlt">nest</span> building behaviour in 30% of animals from both cohorts that was attenuated by escitalopram to pre-treatment <span class="hlt">nesting</span> scores of the larger group. In summary, behavioural and drug-treatment evidence confirms that deer mouse behaviour does indeed resemble symptom heterogeneity related to OCD, and as such expands its face and predictive validity for the disorder. PMID:27154874</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3860902','PMC'); return false;" href="http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3860902"><span id="translatedtitle">Structural <span class="hlt">Nested</span> Cumulative Failure Time <span class="hlt">Models</span> to Estimate the Effects of Interventions</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Picciotto, Sally; Hernán, Miguel A.; Page, John H.; Young, Jessica G.; Robins, James M.</p> <p>2013-01-01</p> <p>In the presence of time-varying confounders affected by prior treatment, standard statistical methods for failure time analysis may be biased. Methods that correctly adjust for this type of covariate include the parametric g-formula, inverse probability weighted estimation of marginal structural Cox proportional hazards <span class="hlt">models</span>, and g-estimation of structural <span class="hlt">nested</span> accelerated failure time <span class="hlt">models</span>. In this article, we propose a novel method to estimate the causal effect of a time-dependent treatment on failure in the presence of informative right-censoring and time-dependent confounders that may be affected by past treatment: g-estimation of structural <span class="hlt">nested</span> cumulative failure time <span class="hlt">models</span> (SNCFTMs). An SNCFTM considers the conditional effect of a final treatment at time m on the outcome at each later time k by <span class="hlt">modeling</span> the ratio of two counterfactual cumulative risks at time k under treatment regimes that differ only at time m. Inverse probability weights are used to adjust for informative censoring. We also present a procedure that, under certain “no-interaction” conditions, uses the g-estimates of the <span class="hlt">model</span> parameters to calculate unconditional cumulative risks under nondynamic (static) treatment regimes. The procedure is illustrated with an example using data from a longitudinal cohort study, in which the “treatments” are healthy behaviors and the outcome is coronary heart disease. PMID:24347749</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://eric.ed.gov/?q=Nests&pg=2&id=EJ679891','ERIC'); return false;" href="http://eric.ed.gov/?q=Nests&pg=2&id=EJ679891"><span id="translatedtitle"><span class="hlt">Nesting</span> Instincts.</span></a></p> <p><a target="_blank" href="http://www.eric.ed.gov/ERICWebPortal/search/extended.jsp?_pageLabel=advanced">ERIC Educational Resources Information Center</a></p> <p>Greenman, Geri</p> <p>2003-01-01</p> <p>Describes an art project where beginning drawing students used values and chiaroscuro techniques to draw bird <span class="hlt">nests</span>. Explains how the students observed the <span class="hlt">nest</span> that was displayed in the art classroom. Discusses the steps involved in creating the artworks. (CMK)</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/19850016369','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19850016369"><span id="translatedtitle">Variational <span class="hlt">mesoscale</span> satellite data assimilation and initialization</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Sasaki, Y. K.; Goerss, J. S.</p> <p>1985-01-01</p> <p>The problems of <span class="hlt">mesoscale</span> satellite data assimilation were examined. Assimilation of satellite data to improve the forecasts made by <span class="hlt">mesoscale</span> forecast <span class="hlt">models</span> was undertaken. Assimilation of high resolution satellite derived temperature data into a <span class="hlt">mesoscale</span> <span class="hlt">model</span> with horizontal resolution of 50 to 60 km is reported. Unlike global assimilation, in which a small portion of the forecast <span class="hlt">model</span> domain is subject to data insertion at virtually every time step, the <span class="hlt">mesoscale</span> assimilation virtually all of the forecast <span class="hlt">model</span> domain is subject to data insertion at one time step. The <span class="hlt">mesoscale</span> problem lends itself naturally to intermittent data assimilation and the forecast <span class="hlt">model</span> is reinitialized whenever a new satellite pass covers its domain with data. The satellite data assimilation as an initialization problem are discussed.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4670219','PMC'); return false;" href="http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4670219"><span id="translatedtitle">Time to Integrate to <span class="hlt">Nest</span> Test Evaluation in a Mouse DSS-Colitis <span class="hlt">Model</span></span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Häger, Christine; Keubler, Lydia M.; Biernot, Svenja; Dietrich, Jana; Buchheister, Stephanie; Buettner, Manuela; Bleich, André</p> <p>2015-01-01</p> <p>Severity assessment in laboratory animals is an important issue regarding the implementation of the 3R concept into biomedical research and pivotal in current EU regulations. In mouse <span class="hlt">models</span> of inflammatory bowel disease severity assessment is usually undertaken by clinical scoring, especially by monitoring reduction of body weight. This requires daily observance and handling of each mouse, which is time consuming, stressful for the animal and necessitates an experienced observer. The time to integrate to <span class="hlt">nest</span> test (TINT) is an easily applicable test detecting disturbed welfare by measuring the time interval mice need to integrate <span class="hlt">nesting</span> material to an existing <span class="hlt">nest</span>. Here, TINT was utilized to assess severity in a mouse DSS-colitis <span class="hlt">model</span>. TINT results depended on the group size of mice maintained per cage with most consistent time intervals measured when co-housing 4 to 5 mice. Colitis was induced with 1% or 1.5% DSS in group-housed WT and Cd14-deficient mice. Higher clinical scores and loss of body weight were detected in 1.5% compared to 1% DSS treated mice. TINT time intervals showed no dose dependent differences. However, increased clinical scores, body weight reductions, and increased TINT time intervals were detected in Cd14-/- compared to WT mice revealing mouse strain related differences. Therefore, TINT is an easily applicable method for severity assessment in a mouse colitis <span class="hlt">model</span> detecting CD14 related differences, but not dose dependent differences. As TINT revealed most consistent results in group-housed mice, we recommend utilization as an additional method substituting clinical monitoring of the individual mouse. PMID:26637175</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/pages/biblio/1235292-top-down-estimate-methane-emissions-california-using-mesoscale-inverse-modeling-technique-south-coast-air-basin','SCIGOV-DOEP'); return false;" href="http://www.osti.gov/pages/biblio/1235292-top-down-estimate-methane-emissions-california-using-mesoscale-inverse-modeling-technique-south-coast-air-basin"><span id="translatedtitle">Top-down estimate of methane emissions in California using a <span class="hlt">mesoscale</span> inverse <span class="hlt">modeling</span> technique: The South Coast Air Basin</span></a></p> <p><a target="_blank" href="http://www.osti.gov/pages">DOE PAGESBeta</a></p> <p>Cui, Yu Yan; Brioude, Jerome; McKeen, Stuart A.; Angevine, Wayne M.; Kim, Si -Wan; Frost, Gregory J.; Ahmadov, Ravan; Peischl, Jeff; Bousserez, Nicolas; Liu, Zhen; et al</p> <p>2015-07-28</p> <p>Methane (CH4) is the primary component of natural gas and has a larger global warming potential than CO2. Some recent top-down studies based on observations showed CH4 emissions in California's South Coast Air Basin (SoCAB) were greater than those expected from population-apportioned bottom-up state inventories. In this study, we quantify CH4 emissions with an advanced <span class="hlt">mesoscale</span> inverse <span class="hlt">modeling</span> system at a resolution of 8 km × 8 km, using aircraft measurements in the SoCAB during the 2010 Nexus of Air Quality and Climate Change campaign to constrain the inversion. To simulate atmospheric transport, we use the FLEXible PARTicle-Weather Research andmore » Forecasting (FLEXPART-WRF) Lagrangian particle dispersion <span class="hlt">model</span> driven by three configurations of the Weather Research and Forecasting (WRF) <span class="hlt">mesoscale</span> <span class="hlt">model</span>. We determine surface fluxes of CH4 using a Bayesian least squares method in a four-dimensional inversion. Simulated CH4 concentrations with the posterior emission inventory achieve much better correlations with the measurements (R2 = 0.7) than using the prior inventory (U.S. Environmental Protection Agency's National Emission Inventory 2005, R2 = 0.5). The emission estimates for CH4 in the posterior, 46.3 ± 9.2 Mg CH4/h, are consistent with published observation-based estimates. Changes in the spatial distribution of CH4 emissions in the SoCAB between the prior and posterior inventories are discussed. Missing or underestimated emissions from dairies, the oil/gas system, and landfills in the SoCAB seem to explain the differences between the prior and posterior inventories. Furthermore, we estimate that dairies contributed 5.9 ± 1.7 Mg CH4/h and the two sectors of oil and gas industries (production and downstream) and landfills together contributed 39.6 ± 8.1 Mg CH4/h in the SoCAB.« less</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015JGRD..120.6698C','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015JGRD..120.6698C"><span id="translatedtitle">Top-down estimate of methane emissions in California using a <span class="hlt">mesoscale</span> inverse <span class="hlt">modeling</span> technique: The South Coast Air Basin</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Cui, Yu Yan; Brioude, Jerome; McKeen, Stuart A.; Angevine, Wayne M.; Kim, Si-Wan; Frost, Gregory J.; Ahmadov, Ravan; Peischl, Jeff; Bousserez, Nicolas; Liu, Zhen; Ryerson, Thomas B.; Wofsy, Steve C.; Santoni, Gregory W.; Kort, Eric A.; Fischer, Marc L.; Trainer, Michael</p> <p>2015-07-01</p> <p>Methane (CH4) is the primary component of natural gas and has a larger global warming potential than CO2. Recent top-down studies based on observations showed CH4 emissions in California's South Coast Air Basin (SoCAB) were greater than those expected from population-apportioned bottom-up state inventories. In this study, we quantify CH4 emissions with an advanced <span class="hlt">mesoscale</span> inverse <span class="hlt">modeling</span> system at a resolution of 8 km × 8 km, using aircraft measurements in the SoCAB during the 2010 Nexus of Air Quality and Climate Change campaign to constrain the inversion. To simulate atmospheric transport, we use the FLEXible PARTicle-Weather Research and Forecasting (FLEXPART-WRF) Lagrangian particle dispersion <span class="hlt">model</span> driven by three configurations of the Weather Research and Forecasting (WRF) <span class="hlt">mesoscale</span> <span class="hlt">model</span>. We determine surface fluxes of CH4 using a Bayesian least squares method in a four-dimensional inversion. Simulated CH4 concentrations with the posterior emission inventory achieve much better correlations with the measurements (R2 = 0.7) than using the prior inventory (U.S. Environmental Protection Agency's National Emission Inventory 2005, R2 = 0.5). The emission estimates for CH4 in the posterior, 46.3 ± 9.2 Mg CH4/h, are consistent with published observation-based estimates. Changes in the spatial distribution of CH4 emissions in the SoCAB between the prior and posterior inventories are discussed. Missing or underestimated emissions from dairies, the oil/gas system, and landfills in the SoCAB seem to explain the differences between the prior and posterior inventories. We estimate that dairies contributed 5.9 ± 1.7 Mg CH4/h and the two sectors of oil and gas industries (production and downstream) and landfills together contributed 39.6 ± 8.1 Mg CH4/h in the SoCAB.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2007AGUFM.A12D..05S&link_type=ABSTRACT','NASAADS'); return false;" href="http://adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2007AGUFM.A12D..05S&link_type=ABSTRACT"><span id="translatedtitle">Hurricane <span class="hlt">Modeling</span> and Supercomputing: Can a global <span class="hlt">mesoscale</span> <span class="hlt">model</span> be useful in improving forecasts of tropical cyclogenesis?</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Shen, B.; Tao, W.; Atlas, R.</p> <p>2007-12-01</p> <p>Hurricane <span class="hlt">modeling</span>, along with guidance from observations, has been used to help construct hurricane theories since the 1960s. CISK (conditional instability of the second kind, Charney and Eliassen 1964; Ooyama 1964,1969) and WISHE (wind-induced surface heat exchange, Emanuel 1986) are among the well-known theories being used to understand hurricane intensification. For hurricane genesis, observations have indicated the importance of large-scale flows (e.g., the Madden-Julian Oscillation or MJO, Maloney and Hartmann, 2000) on the modulation of hurricane activity. Recent <span class="hlt">modeling</span> studies have focused on the role of the MJO and Rossby waves (e.g., Ferreira and Schubert, 1996; Aivyer and Molinari, 2003) and/or the interaction of small-scale vortices (e.g., Holland 1995; Simpson et al. 1997; Hendrick et al. 2004), of which determinism could be also built by large-scale flows. The aforementioned studies suggest a unified view on hurricane formation, consisting of multiscale processes such as scale transition (e.g., from the MJO to Equatorial Rossby Waves and from waves to vortices), and scale interactions among vortices, convection, and surface heat and moisture fluxes. To depict the processes in the unified view, a high-resolution global <span class="hlt">model</span> is needed. During the past several years, supercomputers have enabled the deployment of ultra-high resolution global <span class="hlt">models</span>, obtaining remarkable forecasts of hurricane track and intensity (Atlas et al. 2005; Shen et al. 2006). In this work, hurricane genesis is investigated with the aid of a global <span class="hlt">mesoscale</span> <span class="hlt">model</span> on the NASA Columbia supercomputer by conducting numerical experiments on the genesis of six consecutive tropical cyclones (TCs) in May 2002. These TCs include two pairs of twin TCs in the Indian Ocean, Supertyphoon Hagibis in the West Pacific Ocean and Hurricane Alma in the East Pacific Ocean. It is found that the <span class="hlt">model</span> is capable of predicting the genesis of five of these TCs about two to three days in advance. Our</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2004APS..MARB29007G','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2004APS..MARB29007G"><span id="translatedtitle">A <span class="hlt">Model</span> for Incorporating Chemical Reactions in <span class="hlt">Mesoscale</span> <span class="hlt">Modeling</span> of Laser Ablation of Polymers</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Garrison, Barbara J.; Yingling, Yaroslava G.</p> <p>2004-03-01</p> <p>We have developed a methodology for including effects of chemical reactions in coarse-grained computer simulations such as those that use the united atom or bead and spring approximations. The new coarse-grained chemical reaction <span class="hlt">model</span> (CGCRM) adopts the philosophy of kinetic Monte Carlo approaches and includes a probabilistic element to predicting when reactions occur, thus obviating the need for a chemically correct interaction potential. The CGCRM uses known chemical reactions along with their probabilities and exothermicities for a specific material in order to assess the effect of chemical reactions on a physical process of interest. The reaction event in the simulation is implemented by removing the reactant molecules from the simulation and replacing them with product molecules. The position of the product molecules is carefully adjusted to make sure that the total energy change of the system corresponds to the reaction exothermicity. The CGCR <span class="hlt">model</span> was initially implemented in simulations of laser irradiation at fluences such that there is ablation or massive removal of material. The initial reaction is photon cleavage of a chemical bond thus creating two radicals that can undergo subsequent abstraction and radical-radical recombination reactions. The talk will discuss application of the <span class="hlt">model</span> to photoablation of PMMA. Y. G. Yingling, L. V. Zhigilei and B. J. Garrison, J. Photochemistry and Photobiology A: Chemistry, 145, 173-181 (2001); Y. G. Yingling and B. J. Garrison, Chem. Phys. Lett., 364, 237-243 (2002).</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://cfpub.epa.gov/si/si_public_record_report.cfm?dirEntryId=41999&keyword=Cyclones&actType=&TIMSType=+&TIMSSubTypeID=&DEID=&epaNumber=&ntisID=&archiveStatus=Both&ombCat=Any&dateBeginCreated=&dateEndCreated=&dateBeginPublishedPresented=&dateEndPublishedPresented=&dateBeginUpdated=&dateEndUpdated=&dateBeginCompleted=&dateEndCompleted=&personID=&role=Any&journalID=&publisherID=&sortBy=revisionDate&count=50&CFID=67285374&CFTOKEN=74107675','EPA-EIMS'); return false;" href="http://cfpub.epa.gov/si/si_public_record_report.cfm?dirEntryId=41999&keyword=Cyclones&actType=&TIMSType=+&TIMSSubTypeID=&DEID=&epaNumber=&ntisID=&archiveStatus=Both&ombCat=Any&dateBeginCreated=&dateEndCreated=&dateBeginPublishedPresented=&dateEndPublishedPresented=&dateBeginUpdated=&dateEndUpdated=&dateBeginCompleted=&dateEndCompleted=&personID=&role=Any&journalID=&publisherID=&sortBy=revisionDate&count=50&CFID=67285374&CFTOKEN=74107675"><span id="translatedtitle">USE OF FOUR-DIMENSIONAL DATA ASSIMILATION IN A LIMITED-AREA <span class="hlt">MESOSCALE</span> <span class="hlt">MODEL</span> - PART II: EFFECTS OF DATA ASSIMILATION WITHIN THE PLANETARY BOUNDARY LAYER</span></a></p> <p><a target="_blank" href="http://oaspub.epa.gov/eims/query.page">EPA Science Inventory</a></p> <p></p> <p></p> <p>A four-dimensional data assimilation (FDDA) scheme based on Newtonian relaxation or nudging has been developed and evaluated in the Pennsylvania State University/National Center for Atmospheric Research (PSU/NCAR) Limited-Area <span class="hlt">Mesoscale</span> <span class="hlt">Model</span>. t was shown in Part I of this study ...</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014AGUFM.H31A0590L','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014AGUFM.H31A0590L"><span id="translatedtitle">Automatic Multi-Scale Calibration Procedure for <span class="hlt">Nested</span> Hydrological-Hydrogeological Regional <span class="hlt">Models</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Labarthe, B.; Abasq, L.; Flipo, N.; de Fouquet, C. D.</p> <p>2014-12-01</p> <p>Large hydrosystem <span class="hlt">modelling</span> and understanding is a complex process depending on regional and local processes. A <span class="hlt">nested</span> interface concept has been implemented in the hydrosystem <span class="hlt">modelling</span> platform for a large alluvial plain <span class="hlt">model</span> (300 km2) part of a 11000 km2 multi-layer aquifer system, included in the Seine basin (65000 km2, France). The platform couples hydrological and hydrogeological processes through four spatially distributed modules (Mass balance, Unsaturated Zone, River and Groundwater). An automatic multi-scale calibration procedure is proposed. Using different data sets from regional scale (117 gauging stations and 183 piezometers over the 65000 km2) to the intermediate scale(dense past piezometric snapshot), it permits the calibration and homogenization of <span class="hlt">model</span> parameters over scales.The stepwise procedure starts with the optimisation of the water mass balance parameters at regional scale using a conceptual 7 parameters bucket <span class="hlt">model</span> coupled with the inverse <span class="hlt">modelling</span> tool PEST. The multi-objective function is derived from river discharges and their de-composition by hydrograph separation. The separation is performed at each gauging station using an automatic procedure based one Chapman filter. Then, the <span class="hlt">model</span> is run at the regional scale to provide recharge estimate and regional fluxes to the groundwater local <span class="hlt">model</span>. Another inversion method is then used to determine the local hydrodynamic parameters. This procedure used an initial kriged transmissivity field which is successively updated until the simulated hydraulic head distribution equals a reference one obtained by krigging. Then, the local parameters are upscaled to the regional <span class="hlt">model</span> by renormalisation procedure.This multi-scale automatic calibration procedure enhances both the local and regional processes representation. Indeed, it permits a better description of local heterogeneities and of the associated processes which are transposed into the regional <span class="hlt">model</span>, improving the overall performances</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/25001914','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/25001914"><span id="translatedtitle"><span class="hlt">Nest</span>-site selection analysis of hooded crane (Grus monacha) in Northeastern China based on a multivariate ensemble <span class="hlt">model</span>.</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Jiao, Shengwu; Guo, Yumin; Huettmann, Falk; Lei, Guangchun</p> <p>2014-07-01</p> <p>Avian <span class="hlt">nest</span>-site selection is an important research and management subject. The hooded crane (Grus monacha) is a vulnerable (VU) species according to the IUCN Red List. Here, we present the first long-term Chinese legacy <span class="hlt">nest</span> data for this species (1993-2010) with publicly available metadata. Further, we provide the first study that reports findings on multivariate <span class="hlt">nest</span> habitat preference using such long-term field data for this species. Our work was carried out in Northeastern China, where we found and measured 24 <span class="hlt">nests</span> and 81 randomly selected control plots and their environmental parameters in a vast landscape. We used machine learning (stochastic boosted regression trees) to quantify <span class="hlt">nest</span> selection. Our analysis further included varclust (R Hmisc) and (TreenNet) to address statistical correlations and two-way interactions. We found that from an initial list of 14 measured field variables, water area (+), water depth (+) and shrub coverage (-) were the main explanatory variables that contributed to hooded crane <span class="hlt">nest</span>-site selection. Agricultural sites played a smaller role in the selection of these <span class="hlt">nests</span>. Our results are important for the conservation management of cranes all over East Asia and constitute a defensible and quantitative basis for predictive <span class="hlt">models</span>. PMID:25001914</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4276544','PMC'); return false;" href="http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4276544"><span id="translatedtitle">Testing Goodness-of-Fit for the Proportional Hazards <span class="hlt">Model</span> based on <span class="hlt">Nested</span> Case-Control Data</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Lu, Wenbin; Liu, Mengling; Chen, Yi-Hau</p> <p>2014-01-01</p> <p>Summary <span class="hlt">Nested</span> case-control sampling is a popular design for large epidemiological cohort studies due to its cost effectiveness. A number of methods have been developed for the estimation of the proportional hazards <span class="hlt">model</span> with <span class="hlt">nested</span> case-control data; however, the evaluation of <span class="hlt">modeling</span> assumption is less attended. In this paper, we propose a class of goodness-of-fit test statistics for testing the proportional hazards assumption based on <span class="hlt">nested</span> case-control data. The test statistics are constructed based on asymptotically mean-zero processes derived from Samuelsen’s maximum pseudo-likelihood estimation method. In addition, we develop an innovative resampling scheme to approximate the asymptotic distribution of the test statistics while accounting for the dependent sampling scheme of <span class="hlt">nested</span> case-control design. Numerical studies are conducted to evaluate the performance of our proposed approach, and an application to the Wilms’ Tumor Study is given to illustrate the methodology. PMID:25298193</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_17");'>17</a></li> <li><a href="#" onclick='return showDiv("page_18");'>18</a></li> <li class="active"><span>19</span></li> <li><a href="#" onclick='return showDiv("page_20");'>20</a></li> <li><a href="#" onclick='return showDiv("page_21");'>21</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_19 --> <div id="page_20" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_18");'>18</a></li> <li><a href="#" onclick='return showDiv("page_19");'>19</a></li> <li class="active"><span>20</span></li> <li><a href="#" onclick='return showDiv("page_21");'>21</a></li> <li><a href="#" onclick='return showDiv("page_22");'>22</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="381"> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/25298193','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/25298193"><span id="translatedtitle">Testing goodness-of-fit for the proportional hazards <span class="hlt">model</span> based on <span class="hlt">nested</span> case-control data.</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Lu, Wenbin; Liu, Mengling; Chen, Yi-Hau</p> <p>2014-12-01</p> <p><span class="hlt">Nested</span> case-control sampling is a popular design for large epidemiological cohort studies due to its cost effectiveness. A number of methods have been developed for the estimation of the proportional hazards <span class="hlt">model</span> with <span class="hlt">nested</span> case-control data; however, the evaluation of <span class="hlt">modeling</span> assumption is less attended. In this article, we propose a class of goodness-of-fit test statistics for testing the proportional hazards assumption based on <span class="hlt">nested</span> case-control data. The test statistics are constructed based on asymptotically mean-zero processes derived from Samuelsen's maximum pseudo-likelihood estimation method. In addition, we develop an innovative resampling scheme to approximate the asymptotic distribution of the test statistics while accounting for the dependent sampling scheme of <span class="hlt">nested</span> case-control design. Numerical studies are conducted to evaluate the performance of our proposed approach, and an application to the Wilms' Tumor Study is given to illustrate the methodology. PMID:25298193</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://ntrs.nasa.gov/search.jsp?R=20020042705&hterms=urban+heat+island&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D50%26Ntt%3Durban%2Bheat%2Bisland','NASA-TRS'); return false;" href="http://ntrs.nasa.gov/search.jsp?R=20020042705&hterms=urban+heat+island&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D50%26Ntt%3Durban%2Bheat%2Bisland"><span id="translatedtitle">An Investigation of the Influence of Urban Areas on Rainfall Using a Cloud-<span class="hlt">Mesoscale</span> <span class="hlt">Model</span> and the TRMM Satellite</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Shepherd, J. Marshall; Starr, David O'C (Technical Monitor)</p> <p>2001-01-01</p> <p>A recent paper by Shepherd and Pierce (conditionally accepted to Journal of Applied Meteorology) used rainfall data from the Precipitation Radar on NASA's Tropical Rainfall Measuring Mission's (TRMM) satellite to identify warm season rainfall anomalies downwind of major urban areas. A convective-<span class="hlt">mesoscale</span> <span class="hlt">model</span> with extensive land-surface processes is employed to (a) determine if an urban heat island (UHI) thermal perturbation can induce a dynamic response to affect rainfall processes and (b) quantify the impact of the following three factors on the evolution of rainfall: (1) urban surface roughness, (2) magnitude of the UHI temperature anomaly, and (3) physical size of the UHI temperature anomaly. The sensitivity experiments are achieved by inserting a slab of land with urban properties (e.g. roughness length, albedo, thermal character) within a rural surface environment and varying the appropriate lower boundary condition parameters. Early analysis suggests that urban surface roughness (through turbulence and low-level convergence) may control timing and initial location of UHI-induced convection. The magnitude of the heat island appears to be closely linked to the total rainfall amount with minor impact on timing and location. The physical size of the city may predominantly impact on the location of UHI-induced rainfall anomaly. The UHI factor parameter space will be thoroughly investigated with respect to their effects on rainfall amount, location, and timing. This study extends prior numerical investigations of the impact of urban surfaces on meteorological processes, particularly rainfall development. The work also contains several novel aspects, including the application of a high-resolution (less than I km) cloud-<span class="hlt">mesoscale</span> <span class="hlt">model</span> to investigate urban-induce rainfall process; investigation of thermal magnitude of the UHI on rainfall process; and investigation of UHI physical size on rainfall processes.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2013EGUGA..1511259P','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2013EGUGA..1511259P"><span id="translatedtitle">Point-Specific Wind Forecasting using the HARMONIE <span class="hlt">Mesoscale</span> Forecast <span class="hlt">Model</span> with Bayes <span class="hlt">Model</span> Averaging for Fine-Tuning</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Peters, Martin; McKinstry, Alastair; O'Brien, Enda; Ralph, Adam; Sheehy, Michael</p> <p>2013-04-01</p> <p>Two distinct elements seem to be required to make accurate wind-speed forecasts for wind-farms: the first is deterministic output from a weather forecast <span class="hlt">model</span>, and the second is some probabilistic or statistical post-processing to account for local biases, or systematic errors in the <span class="hlt">model</span>. A variety of statistical post-processing schemes are available, and are generally worthwhile since they are cheap and at worst do no harm. More typically, they demonstrably improve the accuracy of the deterministic forecast. Gridded output from the operational HARMONIE <span class="hlt">mesoscale</span> weather forecast <span class="hlt">model</span> has been interpolated to forecast winds at the precise (3-dimensional) location of the met-mast of a wind farm in southwest Ireland. A sequence of 48-hour forecasts run at 6-hourly intervals for over one year have been validated against winds recorded at turbine height on the mast. All the interpolated deterministic forecasts are also post-processed using Bayesian <span class="hlt">Model</span> Averaging (BMA) to remove systematic local bias, and to provide forecasts in a calibrated probabilistic format. Three variants of the HARMONIE <span class="hlt">model</span> were also run during October 2010 and validated against the winds recorded at the met-mast. The HARMONIE variant with the most advanced physics and the larger domain was the most accurate in forecasting met-mast windspeed, with mean average error (MAE) of 1.5 ms-1 (i.e., about 10% of mean wind speed). The BMA analysis for this short period (using a 25-day training period) did not change the MAE for the best HARMONIE configuration, but did improve the MAE of the other two by about 15%. The most advanced HARMONIE configuration proved more accurate than an ensemble of all three. There was negligible degradation in the skill of the hourly forecasts, at least out to 24 hours (i.e., 24-hr forecasts were only marginally less accurate than 0-hr analyses or 1-hr forecasts). Results are presented from the operational 48-hr HARMONIE forecasts collected during Jan.-Mar. 2012, as</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016MNRAS.458L..84A','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016MNRAS.458L..84A"><span id="translatedtitle">A method for comparing non-<span class="hlt">nested</span> <span class="hlt">models</span> with application to astrophysical searches for new physics</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Algeri, Sara; Conrad, Jan; van Dyk, David A.</p> <p>2016-05-01</p> <p>Searches for unknown physics and decisions between competing astrophysical <span class="hlt">models</span> to explain data both rely on statistical hypothesis testing. The usual approach in searches for new physical phenomena is based on the statistical likelihood ratio test and its asymptotic properties. In the common situation, when neither of the two <span class="hlt">models</span> under comparison is a special case of the other i.e. when the hypotheses are non-<span class="hlt">nested</span>, this test is not applicable. In astrophysics, this problem occurs when two <span class="hlt">models</span> that reside in different parameter spaces are to be compared. An important example is the recently reported excess emission in astrophysical γ-rays and the question whether its origin is known astrophysics or dark matter. We develop and study a new, simple, generally applicable, frequentist method and validate its statistical properties using a suite of simulations studies. We exemplify it on realistic simulated data of the Fermi-Large Area Telescope γ-ray satellite, where non-<span class="hlt">nested</span> hypotheses testing appears in the search for particle dark matter.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2005JMS....56...45O','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2005JMS....56...45O"><span id="translatedtitle">A rapid response nowcast/forecast system using multiply <span class="hlt">nested</span> ocean <span class="hlt">models</span> and distributed data systems</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Onken, Reiner; Robinson, Allan R.; Kantha, Lakshmi; Lozano, Carlos J.; Haley, Patrick J.; Carniel, Sandro</p> <p>2005-05-01</p> <p>Logistics and results of a real-time <span class="hlt">modeling</span> effort, which took place in fall 2000 in the waters between Corsica and Italy in the Mediterranean Sea, are presented. The major objective was to <span class="hlt">nest</span> a high-resolution local version of the Harvard Ocean Prediction System (HOPS) into a coarse resolution Colorado University Princeton Ocean <span class="hlt">Model</span> (CUPOM) covering the northern part of the Western Mediterranean. Due to the different designs of CUPOM and HOPS, traditional <span class="hlt">nesting</span> methods were not successful. Therefore, a new method was developed that assimilated the CUPOM prognostic fields into HOPS instead of prescribing them only along the open boundaries. Another objective of the effort was to set up and test a data distribution system, providing Internet-based rapid data transfer among the project partners being partly at sea and partly on land in different continents. It is shown that such a system works, enabling turnaround times of less than a day from the time when measurements are taken to the release of the <span class="hlt">model</span> forecast.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/19800009377','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19800009377"><span id="translatedtitle">Development of a severe local storm prediction system: A 60-day test of a <span class="hlt">mesoscale</span> primitive equation <span class="hlt">model</span></span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Paine, D. A.; Zack, J. W.; Kaplan, M. L.</p> <p>1979-01-01</p> <p>The progress and problems associated with the dynamical forecast system which was developed to predict severe storms are examined. The meteorological problem of severe convective storm forecasting is reviewed. The cascade hypothesis which forms the theoretical core of the <span class="hlt">nested</span> grid dynamical numerical <span class="hlt">modelling</span> system is described. The dynamical and numerical structure of the <span class="hlt">model</span> used during the 1978 test period is presented and a preliminary description of a proposed multigrid system for future experiments and tests is provided. Six cases from the spring of 1978 are discussed to illustrate the <span class="hlt">model</span>'s performance and its problems. Potential solutions to the problems are examined.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2016IJMPB..3041002G&link_type=ABSTRACT','NASAADS'); return false;" href="http://adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2016IJMPB..3041002G&link_type=ABSTRACT"><span id="translatedtitle">The ellipsoidal <span class="hlt">nested</span> sampling and the expression of the <span class="hlt">model</span> uncertainty in measurements</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Gervino, Gianpiero; Mana, Giovanni; Palmisano, Carlo</p> <p>2016-07-01</p> <p>In this paper, we consider the problems of identifying the most appropriate <span class="hlt">model</span> for a given physical system and of assessing the <span class="hlt">model</span> contribution to the measurement uncertainty. The above problems are studied in terms of Bayesian <span class="hlt">model</span> selection and <span class="hlt">model</span> averaging. As the evaluation of the “evidence” Z, i.e., the integral of Likelihood × Prior over the space of the measurand and the parameters, becomes impracticable when this space has 20 ÷ 30 dimensions, it is necessary to consider an appropriate numerical strategy. Among the many algorithms for calculating Z, we have investigated the ellipsoidal <span class="hlt">nested</span> sampling, which is a technique based on three pillars: The study of the iso-likelihood contour lines of the integrand, a probabilistic estimate of the volume of the parameter space contained within the iso-likelihood contours and the random samplings from hyperellipsoids embedded in the integration variables. This paper lays out the essential ideas of this approach.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/19790006527','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19790006527"><span id="translatedtitle">A <span class="hlt">nested</span> numerical tidal <span class="hlt">model</span> of the southern New England bight</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Gordon, R. B.; Spaulding, M. L.</p> <p>1979-01-01</p> <p>Efforts were focused on the development and application of a three-dimensional numerical <span class="hlt">model</span> for predicting pollutant and sediment transport in estuarine and coastal environments. To successfully apply the pollutant and sediment transport <span class="hlt">model</span> to Rhode Island coastal waters, it was determined that the flow field in this region had to be better described through the use of existing numerical circulation <span class="hlt">models</span>. A <span class="hlt">nested</span>, barotropic numerical tidal <span class="hlt">model</span> was applied to the southern New England Bight (Long Island, Block Island, Rhode Island Sounds, Buzzards Bay, and the shelf south of Block Island). Forward time and centered spatial differences were employed with the bottom friction term evaluated at both time levels. Using existing tide records on the New England shelf, adequate information was available to specify the tide height boundary condition further out on the shelf. Preliminary results are within the accuracy of the National Ocean Survey tide table data.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/26115504','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/26115504"><span id="translatedtitle">Structural <span class="hlt">Nested</span> Mean <span class="hlt">Models</span> to Estimate the Effects of Time-Varying Treatments on Clustered Outcomes.</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>He, Jiwei; Stephens-Shields, Alisa; Joffe, Marshall</p> <p>2015-11-01</p> <p>In assessing the efficacy of a time-varying treatment structural <span class="hlt">nested</span> <span class="hlt">models</span> (SNMs) are useful in dealing with confounding by variables affected by earlier treatments. These <span class="hlt">models</span> often consider treatment allocation and repeated measures at the individual level. We extend SNMMs to clustered observations with time-varying confounding and treatments. We demonstrate how to formulate <span class="hlt">models</span> with both cluster- and unit-level treatments and show how to derive semiparametric estimators of parameters in such <span class="hlt">models</span>. For unit-level treatments, we consider interference, namely the effect of treatment on outcomes in other units of the same cluster. The properties of estimators are evaluated through simulations and compared with the conventional GEE regression method for clustered outcomes. To illustrate our method, we use data from the treatment arm of a glaucoma clinical trial to compare the effectiveness of two commonly used ocular hypertension medications. PMID:26115504</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/servlets/purl/5899806','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/servlets/purl/5899806"><span id="translatedtitle">MELSAR: a <span class="hlt">mesoscale</span> air quality <span class="hlt">model</span> for complex terrain. Volume 1. Overview, technical description and user's guide</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Allwine, K.J.; Whiteman, C.D.</p> <p>1985-04-01</p> <p>This final report is submitted as part of the Green River Ambient <span class="hlt">Model</span> Assessment (GRAMA) program conducted at the US Department of Energy's Pacific Northwest Laboratory for the US Environmental Protection Agency. The GRAMA program has, as its ultimate goal, the development of validated air quality <span class="hlt">models</span> that can be applied to the complex terrain of the Green River Formation of western Colorado, eastern Utah, and southern Wyoming. The Green River Formation is a geologic formation containing large reserves of oil shale, coal, and other natural resources. Development of these resources may lead to a degradation of the air quality of the region. Air quality <span class="hlt">models</span> are needed immediately for planning and regulatory purposes to assess the magnitude of these regional impacts. This report documents one of the <span class="hlt">models</span> being developed for this purpose within GRAMA - specifically a <span class="hlt">model</span> to predict short averaging time (less than or equal to 24 h) pollutant concentrations resulting from the <span class="hlt">mesoscale</span> transport of pollutant releases from multiple sources. MELSAR has not undergone any rigorous operational testing, sensitivity analyses, or validation studies. Testing and evaluation of the <span class="hlt">model</span> are needed to gain a measure of confidence in the <span class="hlt">model</span>'s performance. This report consists of two volumes. Volume 1 contains the <span class="hlt">model</span> overview, technical description, and user's guide, and Volume 2 contains the Appendices which include listings of the FORTRAN code. 51 refs., 31 figs., 35 tabs.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2002AdAtS..19..487L&link_type=ABSTRACT','NASAADS'); return false;" href="http://adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2002AdAtS..19..487L&link_type=ABSTRACT"><span id="translatedtitle">Climate Simulations based on a different-grid <span class="hlt">nested</span> and coupled <span class="hlt">model</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Li, Dan; Ji, Jinjun; Li, Yinpeng</p> <p>2002-05-01</p> <p>An atmosphere-vegetation interaction <span class="hlt">model</span> (A VIM) has been coupled with a nine-layer General Cir-culation <span class="hlt">Model</span> (GCM) of Institute of Atmospheic Physics/State Key Laboratory of Numerical <span class="hlt">Modeling</span> for Atmospheric Sciences and Geophysical Fluid Dynamics (IAP/LASG), which is rhomboidally truncated at zonal wave number 15, to simulate global climatic mean states. A VIM is a <span class="hlt">model</span> having inter-feedback between land surface processes and eco-physiological processes on land. As the first step to couple land with atmosphere completely, the physiological processes are fixed and only the physical part (generally named the SVAT (soil-vegetation-atmosphere-transfer scheme) <span class="hlt">model</span>) of AVIM is <span class="hlt">nested</span> into IAP/LASG L9R15 GCM. The ocean part of GCM is prescribed and its monthly sea surface temperature (SST) is the climatic mean value. With respect to the low resolution of GCM, i.e., each grid cell having lon-gitude 7.5° and latitude 4.5°, the vegetation is given a high resolution of 1.5° by 1.5° to <span class="hlt">nest</span> and couple the fine grid cells of land with the coarse grid cells of atmosphere. The coupling <span class="hlt">model</span> has been integrated for 15 years and its last ten-year mean of outputs was chosen for analysis. Compared with observed data and NCEP reanalysis, the coupled <span class="hlt">model</span> simulates the main characteris-tics of global atmospheric circulation and the fields of temperature and moisture. In particular, the simu-lated precipitation and surface air temperature have sound results. The work creates a solid base on coupling climate <span class="hlt">models</span> with the biosphere.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014AGUFMOS42A..05K','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014AGUFMOS42A..05K"><span id="translatedtitle">Potential utility of three-dimensional temperature and salinity fields estimated from satellite altimetry and Argo data for improving <span class="hlt">mesoscale</span> reproducibility in regional ocean <span class="hlt">modeling</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Kanki, R.; Uchiyama, Y.; Miyazaki, D.; Takano, A.; Miyazawa, Y.; Yamazaki, H.</p> <p>2014-12-01</p> <p><span class="hlt">Mesoscale</span> oceanic structure and variability are required to be reproduced as accurately as possible in realistic regional ocean <span class="hlt">modeling</span>. Uchiyama et al. (2012) demonstrated with a submesoscale eddy-resolving JCOPE2-ROMS downscaling oceanic <span class="hlt">modeling</span> system that the <span class="hlt">mesoscale</span> reproducibility of the Kuroshio meandering along Japan is significantly improved by introducing a simple restoration to data which we call "TS nudging" (a.k.a. robust diagnosis) where the prognostic temperature and salinity fields are weakly nudged four-dimensionally towards the assimilative JCOPE2 reanalysis (Miyazawa et al., 2009). However, there is not always a reliable reanalysis for oceanic downscaling in an arbitrary region and at an arbitrary time, and therefore alternative dataset should be prepared. Takano et al. (2009) proposed an empirical method to estimate <span class="hlt">mesoscale</span> 3-D thermal structure from the near real-time AVISO altimetry data along with the ARGO float data based on the two-layer <span class="hlt">model</span> of Goni et al. (1996). In the present study, we consider the TS data derived from this method as a candidate. We thus conduct a synoptic forward <span class="hlt">modeling</span> of the Kuroshio using the JCOPE2-ROMS downscaling system to explore potential utility of this empirical TS dataset (hereinafter TUM-TS) by carrying out two runs with the T-S nudging towards 1) the JCOPE2-TS and 2) TUM-TS fields. An example of the comparison between the two ROMS test runs is shown in the attached figure showing the annually averaged surface EKE. Both of TUM-TS and JCOPE2-TS are found to help reproducing the <span class="hlt">mesoscale</span> variance of the Koroshio and its extension as well as its mean paths, surface KE and EKE reasonably well. Therefore, the AVISO-ARGO derived empirical 3-D TS estimation is potentially exploitable for the dataset to conduct the T-S nudging to reproduce <span class="hlt">mesoscale</span> oceanic structure.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015SMaS...24f5031R','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015SMaS...24f5031R"><span id="translatedtitle"><span class="hlt">Modeling</span> of <span class="hlt">mesoscale</span> dispersion effect on the piezoresistivity of carbon nanotube-polymer nanocomposites via 3D computational multiscale micromechanics methods</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Ren, Xiang; Chaurasia, Adarsh K.; Oliva-Avilés, Andrés I.; Ku-Herrera, José J.; Seidel, Gary D.; Avilés, Francis</p> <p>2015-06-01</p> <p>In uniaxial tension and compression experiments, carbon nanotube (CNT)-polymer nanocomposites have demonstrated exceptional mechanical and coupled electrostatic properties in the form of piezoresistivity. In order to better understand the correlation of the piezoresistive response with the CNT dispersion at the <span class="hlt">mesoscale</span>, a 3D computational multiscale micromechanics <span class="hlt">model</span> based on finite element analysis is constructed to predict the effective macroscale piezoresistive response of CNT/polymer nanocomposites. The key factors that may contribute to the overall piezoresistive response, i.e. the nanoscale electrical tunneling effect, the inherent CNT piezoresistivity and the CNT <span class="hlt">mesoscale</span> network effect are incorporated in the <span class="hlt">model</span> based on a 3D multiscale mechanical-electrostatic coupled code. The results not only explain how different nanoscale mechanisms influence the overall macroscale piezoresistive response through the <span class="hlt">mesoscale</span> CNT network, but also give reason and provide bounds for the wide range of gauge factors found in the literature offering insight regarding how control of the <span class="hlt">mesoscale</span> CNT networks can be used to tailor nanocomposite piezoresistive response.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/20100036464','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20100036464"><span id="translatedtitle">An Objective Verification of the North American <span class="hlt">Mesoscale</span> <span class="hlt">Model</span> for Kennedy Space Center and Cape Canaveral Air Force Station</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Bauman, William H., III</p> <p>2010-01-01</p> <p>The 45th Weather Squadron (45 WS) Launch Weather Officers (LWO's) use the 12-km resolution North American <span class="hlt">Mesoscale</span> (NAM) <span class="hlt">model</span> (MesoNAM) text and graphical product forecasts extensively to support launch weather operations. However, the actual performance of the <span class="hlt">model</span> at Kennedy Space Center (KSC) and Cape Canaveral Air Force Station (CCAFS) has not been measured objectively. In order to have tangible evidence of <span class="hlt">model</span> performance, the 45 WS tasked the Applied Meteorology Unit (AMU; Bauman et ai, 2004) to conduct a detailed statistical analysis of <span class="hlt">model</span> output compared to observed values. The <span class="hlt">model</span> products are provided to the 45 WS by ACTA, Inc. and include hourly forecasts from 0 to 84 hours based on <span class="hlt">model</span> initialization times of 00, 06, 12 and 18 UTC. The objective analysis compared the MesoNAM forecast winds, temperature (T) and dew pOint (T d), as well as the changes in these parameters over time, to the observed values from the sensors in the KSC/CCAFS wind tower network shown in Table 1. These objective statistics give the forecasters knowledge of the <span class="hlt">model</span>'s strengths and weaknesses, which will result in improved forecasts for operations.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/20130012521','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20130012521"><span id="translatedtitle">An Objective Verification of the North American <span class="hlt">Mesoscale</span> <span class="hlt">Model</span> for Kennedy Space Center and Cape Canaveral Air Force Station</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Bauman, William H., III</p> <p>2010-01-01</p> <p>The 45th Weather Squadron (45 WS) Launch Weather Officers use the 12-km resolution North American <span class="hlt">Mesoscale</span> (NAM) <span class="hlt">model</span> (MesoNAM) text and graphical product forecasts extensively to support launch weather operations. However, the actual performance of the <span class="hlt">model</span> at Kennedy Space Center (KSC) and Cape Canaveral Air Force Station (CCAFS) has not been measured objectively. In order to have tangible evidence of <span class="hlt">model</span> performance, the 45 WS tasked the Applied Meteorology Unit to conduct a detailed statistical analysis of <span class="hlt">model</span> output compared to observed values. The <span class="hlt">model</span> products are provided to the 45 WS by ACTA, Inc. and include hourly forecasts from 0 to 84 hours based on <span class="hlt">model</span> initialization times of 00, 06, 12 and 18 UTC. The objective analysis compared the MesoNAM forecast winds, temperature and dew point, as well as the changes in these parameters over time, to the observed values from the sensors in the KSC/CCAFS wind tower network. Objective statistics will give the forecasters knowledge of the <span class="hlt">model</span>'s strength and weaknesses, which will result in improved forecasts for operations.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014AGUFM.P51B3938P','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014AGUFM.P51B3938P"><span id="translatedtitle">Interpretation of the Meteorological Gale Environment through Mars Science Laboratory (MSL) Rover Environmental Monitoring Station (REMS) Observations and <span class="hlt">Mesoscale</span> <span class="hlt">Modeling</span> (MRAMS)</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Pla-García, J.; Rafkin, S. C.; Gómez-Elvira, J.; Martín-Torres, J.; Zorzano, M. P.</p> <p>2014-12-01</p> <p>Gale Crater, in which the Mars Science Laboratory (MSL) landed in August 2012, is the most topographically complex area visited to date on Mars. The meteorology within the crater may also be one of the most dynamically complex meteorological environments, because topography is thought to strongly drive the near-surface atmospheric circulations. The Rover Environmental Monitoring Station (REMS) on the Curiosity rover consists of a suite of meteorological instruments that measure pressure, temperature (air and ground), wind (speed and direction), relative humidity, and the UV flux. REMS has provided some clues on the nature of the local meteorology strongly influenced by the complex topography, as predicted by numerous previous studies. As with all single station measurements, the meteorological interpretation is typically hindered by a lack of spatial context in which to place the observations. Numerical <span class="hlt">modeling</span> results, when properly validated against observations, can provide interpretive context. In an effort to better understand the atmospheric circulations of the Gale Crater, the Mars Regional Atmospheric <span class="hlt">Modeling</span> System (MRAMS) was applied to the landing site region using <span class="hlt">nested</span> grids with a spacing of 330 meters on the innermost grid that is centered over the landing site. MRAMS is ideally suited for this investigation; the <span class="hlt">model</span> is explicitly designed to simulate Mars' atmospheric circulations at the <span class="hlt">mesoscale</span> and smaller with realistic, high resolution surface properties. Simulations with MRAMS indicate thermal and wind thermal signatures associated with slope flows, katabatic winds, and nocturnal mixing events that are consistent with the rover environment monitored by REMS. Of particular note is evidence for two distinct air masses—one in the bottom of the crater (a relatively cold potential temperature air mass) and one on the plateau—that have minimal interaction with one another. If there are indeed two distinct air masses, there are strong</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/27100740','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/27100740"><span id="translatedtitle">Compound-Specific Stable Isotope Fractionation of Pesticides and Pharmaceuticals in a <span class="hlt">Mesoscale</span> Aquifer <span class="hlt">Model</span>.</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Schürner, Heide K V; Maier, Michael P; Eckert, Dominik; Brejcha, Ramona; Neumann, Claudia-Constanze; Stumpp, Christine; Cirpka, Olaf A; Elsner, Martin</p> <p>2016-06-01</p> <p>Compound-specific isotope analysis (CSIA) receives increasing interest for its ability to detect natural degradation of pesticides and pharmaceuticals. Despite recent laboratory studies, CSIA investigations of such micropollutants in the environment are still rare. To explore the certainty of information obtainable by CSIA in a near-environmental setting, a pulse of the pesticide bentazone, the pesticide metabolite 2,6-dichlorobenzamide (BAM), and the pharmaceuticals diclofenac and ibuprofen was released into a <span class="hlt">mesoscale</span> aquifer with quasi-two-dimensional flow. Concentration breakthrough curves (BTC) of BAM and ibuprofen demonstrated neither degradation nor sorption. Bentazone was transformed but did not sorb significantly, whereas diclofenac showed both degradation and sorption. Carbon and nitrogen CSIA could be accomplished in similar concentrations as for "traditional" priority pollutants (low μg/L range), however, at the cost of uncertainties (0.4-0.5‰ (carbon), 1‰ (nitrogen)). Nonetheless, invariant carbon and nitrogen isotope values confirmed that BAM was neither degraded nor sorbed, while significant enrichment of (13)C and in particular (15)N corroborated transformation of diclofenac and bentazone. Retardation of diclofenac was reflected in additional (15)N sorption isotope effects, whereas isotope fractionation of transverse dispersion could not be identified. These results provide a benchmark on the performance of CSIA to monitor the reactivity of micropollutants in aquifers and may guide future efforts to accomplish CSIA at even lower concentrations (ng/L range). PMID:27100740</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2011MolPh.109.1873Z&link_type=ABSTRACT','NASAADS'); return false;" href="http://adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2011MolPh.109.1873Z&link_type=ABSTRACT"><span id="translatedtitle">Integration of rotational algorithms into dissipative particle dynamics: <span class="hlt">modeling</span> polyaromatic hydrocarbons on the <span class="hlt">meso-scale</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Zhang, Sheng-Fei; Xu, Jun-Bo; Wen, Hao; Bhattacharjee, Subir</p> <p>2011-08-01</p> <p>Heavy crude oil consists of thousands of compounds, a significant fraction of which have fairly large molecular weights and complex structures. Our work aims at constructing a <span class="hlt">meso-scale</span> platform to explore this complex fluid in terms of microstructure, phase behavior, stability and rheology. In the present study, we focus on the treatment of the structures of fused aromatic rings as rigid body fragments in fractions such as asphaltenes and resins. To derive the rotational motion of rigid bodies in a non-conservative force field, we conduct a comparison of three rigid body rotational algorithms integrated into a standard dissipative particle dynamics (DPD) simulation. The simulation results confirm the superiority of the Quaternion method. To ease any doubt concerning the introduction of rigid bodies into DPD, the performance of the Quaternion method was tested carefully. Finally, the aggregation dynamics of asphaltene in very diluted toluene was investigated. The nanoaggregates are found to experience forming, breaking up and reforming. The sizes of the asphaltene monomer and nanoaggregate are identified. The diffusion coefficient of diluted asphaltene in toluene is similar to that found experimentally. All these results verify the rotational algorithm and encourage us to extend this platform to study the rheological and colloidal characteristics of heavy crude oils in the future.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/1991JGR....9616739P','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/1991JGR....9616739P"><span id="translatedtitle">The <span class="hlt">mesoscale</span> structure of the Leeuwin Current: A comparison of laboratory <span class="hlt">models</span> and satellite imagery</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Pearce, A. F.; Griffiths, R. W.</p> <p>1991-09-01</p> <p>Details of the <span class="hlt">mesoscale</span> variability of the Leeuwin Current are determined from a study of NOAA satellite advanced very high resolution radiometer images over the period 1984-1985 for the area between Shark Bay and Cape Leeuwin on the west coast of Australia. At most times during the selected period there are large wavelike protrusions along the current. During at least three separate periods these appear as a set of three or four roughly equally spaced meanders, or wave crests. Each meander diverts the warm water far offshore of the shelf break, where the core of the southward current is otherwise normally found. Their amplitude generally grows in time, and the anticyclonic motions in the meanders are usually accompanied by cool cyclonic circulations between the meanders. Large meanders are more than 200 km across. Although the flow is unsteady and fronts sometimes translate at speeds of up to 0.8 m s-1, the meanders do not move along the coast and can be followed through the images for 30 to 60 days. These features represent very major diversions to the southward flow in the Leeuwin Current and result in large fluctuations in local current velocity and sea surface temperature. On this scale, the structure of the flow has many features in common with that observed in laboratory experiments with coastal currents driven by steady thermal forcing. Smaller billow structures are also apparent along the strongest temperature fronts in the satellite images.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2009CSR....29..407A','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2009CSR....29..407A"><span id="translatedtitle"><span class="hlt">Mesoscale</span> slope current variability in the Gulf of Lions. Interpretation of in-situ measurements using a three-dimensional <span class="hlt">model</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>André, Gaël; Garreau, Pierre; Fraunie, Philippe</p> <p>2009-02-01</p> <p>The ECOLOPHY experiments aimed at investigating physical exchanges between coastal and open sea. They were carried out in June and December 2005 over the shelf-break in the North-eastern part of the Gulf of Lions (Northwestern Mediterranean Sea). This area is considered to be the generation zone for the eddy and meandering structures of the Northern Current (NC). The objective of the present work is to examine <span class="hlt">mesoscale</span> variability of this coastal slope current in the light of available data. Numerical <span class="hlt">modeling</span> is used to support the field data analysis. ADCP current measurements over a one-year period show that <span class="hlt">mesoscale</span> activity is maximal in late winter, correlating with the seasonal variability of the NC and, also, partly with local winds. Measured currents exhibit <span class="hlt">mesoscale</span> fluctuations with periods ranging from 3 to 30 days, in agreement with previous analyses. Fluctuations of periods longer than 10 days are found to be mainly oriented in the direction of the mean current, whereas more frequently observed high frequency fluctuations tend to be oriented cross-slope, suggesting a relationship with the NC <span class="hlt">mesoscale</span> meandering. Moreover, trajectories of surdrift buoys launched in the NC vein exhibit <span class="hlt">mesoscale</span> phenomena, such as current meanders or eddies and on-shelf intrusions. Numerical <span class="hlt">modeling</span> provides a synoptic point of view and is used hereafter to support physical interpretation of punctual eulerian or lagrangian measurements. Therefore, <span class="hlt">modeled</span> hydrodynamic fields are used to analyze surdrift buoy trajectories and computed vertically averaged current and Ertel potential vorticity provide a better understanding of these behaviors.</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_18");'>18</a></li> <li><a href="#" onclick='return showDiv("page_19");'>19</a></li> <li class="active"><span>20</span></li> <li><a href="#" onclick='return showDiv("page_21");'>21</a></li> <li><a href="#" onclick='return showDiv("page_22");'>22</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_20 --> <div id="page_21" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_19");'>19</a></li> <li><a href="#" onclick='return showDiv("page_20");'>20</a></li> <li class="active"><span>21</span></li> <li><a href="#" onclick='return showDiv("page_22");'>22</a></li> <li><a href="#" onclick='return showDiv("page_23");'>23</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="401"> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/26177286','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/26177286"><span id="translatedtitle">Using Field Data and GIS-Derived Variables to <span class="hlt">Model</span> Occurrence of Williamson's Sapsucker <span class="hlt">Nesting</span> Habitat at Multiple Spatial Scales.</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Drever, Mark C; Gyug, Les W; Nielsen, Jennifer; Stuart-Smith, A Kari; Ohanjanian, I Penny; Martin, Kathy</p> <p>2015-01-01</p> <p>Williamson's sapsucker (Sphyrapicus thyroideus) is a migratory woodpecker that breeds in mixed coniferous forests in western North America. In Canada, the range of this woodpecker is restricted to three small populations in southern British Columbia, precipitating a national listing as 'Endangered' in 2005, and the need to characterize critical habitat for its survival and recovery. We compared habitat attributes between Williamson's sapsucker <span class="hlt">nest</span> territories and random points without <span class="hlt">nests</span> or detections of this sapsucker as part of a resource selection analysis to identify the habitat features that best explain the probability of <span class="hlt">nest</span> occurrence in two separate geographic regions in British Columbia. We compared the relative explanatory power of generalized linear <span class="hlt">models</span> based on field-derived and Geographic Information System (GIS) data within both a 225 m and 800 m radius of a <span class="hlt">nest</span> or random point. The <span class="hlt">model</span> based on field-derived variables explained the most variation in <span class="hlt">nest</span> occurrence in the Okanagan-East Kootenay Region, whereas <span class="hlt">nest</span> occurrence was best explained by GIS information at the 800 m scale in the Western Region. Probability of <span class="hlt">nest</span> occurrence was strongly tied to densities of potential <span class="hlt">nest</span> trees, which included open forests with very large (diameter at breast height, DBH, ≥57.5 cm) western larch (Larix occidentalis) trees in the Okanagan-East Kootenay Region, and very large ponderosa pine (Pinus ponderosa) and large (DBH 17.5-57.5 cm) trembling aspen (Populus tremuloides) trees in the Western Region. Our results have the potential to guide identification and protection of critical habitat as required by the Species at Risk Act in Canada, and to better manage Williamson's sapsucker habitat overall in North America. In particular, management should focus on the maintenance and recruitment of very large western larch and ponderosa pine trees. PMID:26177286</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://ntrs.nasa.gov/search.jsp?R=20020020657&hterms=dry+eye&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D30%26Ntt%3Ddry%2Beye','NASA-TRS'); return false;" href="http://ntrs.nasa.gov/search.jsp?R=20020020657&hterms=dry+eye&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D30%26Ntt%3Ddry%2Beye"><span id="translatedtitle">Combining New Satellite Tools and <span class="hlt">Models</span> to Examine Role of <span class="hlt">Mesoscale</span> Interactions in Formation and Intensification of Tropical Cyclones</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Simpson, Joanne; Pierce, H.; Ritchie, L.; Liu, T.; Brueske, K.; Velden, C.; Halverson, J.; Einaudi, Franco (Technical Monitor)</p> <p>2001-01-01</p> <p>The objective of this research is to start filling the <span class="hlt">mesoscale</span> gap to improve understanding and probability forecasts of formation and intensity variations of tropical cyclones. Sampling by aircraft equipped to measure <span class="hlt">mesoscale</span> processes is expensive, thus confined in place and time. Hence we turn to satellite products. This paper reports preliminary results of a tropical cyclone genesis and early intensification study. We explore the role of <span class="hlt">mesoscale</span> processes using a combination of products from TRMM, QuikSCAT, AMSU, also SSM/I, geosynchronous and <span class="hlt">model</span> output. Major emphasis is on the role of merging <span class="hlt">mesoscale</span> vortices. These initially form in midlevel stratiform cloud. When they form in regions of lowered Rossby radius of deformation (strong background vorticity) the <span class="hlt">mesoscale</span> vortices can last long enough to interact and merge, with the weaker vortex losing vorticity to the stronger, which can then extend down to the surface. In an earlier cyclongenesis case (Oliver 1993) off Australia, intense deep convection occurred when the stronger vortex reached the surface; this vortex became the storm center while the weaker vortex was sheared out as the major rainband. In our study of Atlantic tropical cyclones originating from African waves, we use QuikSCAT to examine surface winds in the African monsoon trough and in the vortices which move westward off the coast, which may or may not undergo genesis (defined by NHC as reaching TD, or tropical depression, with a west wind to the south of the surface low). We use AMSU mainly to examine development of warm cores. TRMM passive microwave TMI is used with SSM/I to look at the rain structure, which often indicates eye formation, and to look at the ice scattering signatures of deep convection. The TRMM precipitation radar, PR, when available, gives precipitation cross sections. So far we have detailed studies of two African-origin cyclones, one which became severe hurricane Floyd 1999, and the other reached TD2 in June</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://ntrs.nasa.gov/search.jsp?R=20020020657&hterms=depression+models&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D10%26Ntt%3Ddepression%2Bmodels','NASA-TRS'); return false;" href="http://ntrs.nasa.gov/search.jsp?R=20020020657&hterms=depression+models&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D10%26Ntt%3Ddepression%2Bmodels"><span id="translatedtitle">Combining New Satellite Tools and <span class="hlt">Models</span> to Examine Role of <span class="hlt">Mesoscale</span> Interactions in Formation and Intensification of Tropical Cyclones</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Simpson, Joanne; Pierce, H.; Ritchie, L.; Liu, T.; Brueske, K.; Velden, C.; Halverson, J.; Einaudi, Franco (Technical Monitor)</p> <p>2001-01-01</p> <p>The objective of this research is to start filling the <span class="hlt">mesoscale</span> gap to improve understanding and probability forecasts of formation and intensity variations of tropical cyclones. Sampling by aircraft equipped to measure <span class="hlt">mesoscale</span> processes is expensive, thus confined in place and time. Hence we turn to satellite products. This paper reports preliminary results of a tropical cyclone genesis and early intensification study. We explore the role of <span class="hlt">mesoscale</span> processes using a combination of products from TRMM, QuikSCAT, AMSU, also SSM/I, geosynchronous and <span class="hlt">model</span> output. Major emphasis is on the role of merging <span class="hlt">mesoscale</span> vortices. These initially form in midlevel stratiform cloud. When they form in regions of lowered Rossby radius of deformation (strong background vorticity) the <span class="hlt">mesoscale</span> vortices can last long enough to interact and merge, with the weaker vortex losing vorticity to the stronger, which can then extend down to the surface. In an earlier cyclongenesis case (Oliver 1993) off Australia, intense deep convection occurred when the stronger vortex reached the surface; this vortex became the storm center while the weaker vortex was sheared out as the major rainband. In our study of Atlantic tropical cyclones originating from African waves, we use QuikSCAT to examine surface winds in the African monsoon trough and in the vortices which move westward off the coast, which may or may not undergo genesis (defined by NHC as reaching TD, or tropical depression, with a west wind to the south of the surface low). We use AMSU mainly to examine development of warm cores. TRMM passive microwave TMI is used with SSM/I to look at the rain structure, which often indicates eye formation, and to look at the ice scattering signatures of deep convection. The TRMM precipitation radar, PR, when available, gives precipitation cross sections. So far we have detailed studies of two African-origin cyclones, one which became severe hurricane Floyd 1999, and the other reached TD2 in June</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016AIPC.1738P0002X','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016AIPC.1738P0002X"><span id="translatedtitle">Tests for ANOVA <span class="hlt">models</span> with a combination of crossed and <span class="hlt">nested</span> designs under heteroscedasticity</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Xu, Liwen; Tian, Maozai</p> <p>2016-06-01</p> <p>In this article we consider unbalanced ANOVA <span class="hlt">models</span> with a combination of crossed and <span class="hlt">nested</span> designs under heteroscedasticity. For the problem of testing no <span class="hlt">nested</span> interaction effects, we propose two tests based on a parametric bootstrap (PB) approach and a generalized p-value approach, respectively. The PB test does not depend on the chosen weights used to define the parameters uniquely. These two tests are compared through their simulated Type I error rates and powers. The simulations indicate that the PB test outperforms the generalized p-value test. The PB test performs very satisfactorily even for extensive cases of samples while the generalized p-value test has Type I error rates much less than the nominal level most of the time. Both tests exhibit similar power properties provided the Type I error rates are close to each other. In some cases, the GF test appears to be more powerful than the PB tests because of its inflated Type I error rates.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2016ACP....16.8983C&link_type=ABSTRACT','NASAADS'); return false;" href="http://adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2016ACP....16.8983C&link_type=ABSTRACT"><span id="translatedtitle">Boundary-layer turbulent processes and <span class="hlt">mesoscale</span> variability represented by numerical weather prediction <span class="hlt">models</span> during the BLLAST campaign</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Couvreux, Fleur; Bazile, Eric; Canut, Guylaine; Seity, Yann; Lothon, Marie; Lohou, Fabienne; Guichard, Françoise; Nilsson, Erik</p> <p>2016-07-01</p> <p>This study evaluates the ability of three operational <span class="hlt">models</span>, with resolution varying from 2.5 to 16 km, to predict the boundary-layer turbulent processes and <span class="hlt">mesoscale</span> variability observed during the Boundary Layer Late-Afternoon and Sunset Turbulence (BLLAST) field campaign. We analyse the representation of the vertical profiles of temperature and humidity and the time evolution of near-surface atmospheric variables and the radiative and turbulent fluxes over a total of 12 intensive observing periods (IOPs), each lasting 24 h. Special attention is paid to the evolution of the turbulent kinetic energy (TKE), which was sampled by a combination of independent instruments. For the first time, this variable, a central one in the turbulence scheme used in AROME and ARPEGE, is evaluated with observations.In general, the 24 h forecasts succeed in reproducing the variability from one day to another in terms of cloud cover, temperature and boundary-layer depth. However, they exhibit some systematic biases, in particular a cold bias within the daytime boundary layer for all <span class="hlt">models</span>. An overestimation of the sensible heat flux is noted for two points in ARPEGE and is found to be partly related to an inaccurate simplification of surface characteristics. AROME shows a moist bias within the daytime boundary layer, which is consistent with overestimated latent heat fluxes. ECMWF presents a dry bias at 2 m above the surface and also overestimates the sensible heat flux. The high-resolution <span class="hlt">model</span> AROME resolves the vertical structures better, in particular the strong daytime inversion and the thin evening stable boundary layer. This <span class="hlt">model</span> is also able to capture some specific observed features, such as the orographically driven subsidence and a well-defined maximum that arises during the evening of the water vapour mixing ratio in the upper part of the residual layer due to fine-scale advection. The <span class="hlt">model</span> reproduces the order of magnitude of spatial variability observed at</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2016PIAHS.373..179K&link_type=ABSTRACT','NASAADS'); return false;" href="http://adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2016PIAHS.373..179K&link_type=ABSTRACT"><span id="translatedtitle">Up-scaling of multi-variable flood loss <span class="hlt">models</span> from objects to land use units at the <span class="hlt">meso-scale</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Kreibich, Heidi; Schröter, Kai; Merz, Bruno</p> <p>2016-05-01</p> <p>Flood risk management increasingly relies on risk analyses, including loss <span class="hlt">modelling</span>. Most of the flood loss <span class="hlt">models</span> usually applied in standard practice have in common that complex damaging processes are described by simple approaches like stage-damage functions. Novel multi-variable <span class="hlt">models</span> significantly improve loss estimation on the micro-scale and may also be advantageous for large-scale applications. However, more input parameters also reveal additional uncertainty, even more in upscaling procedures for <span class="hlt">meso-scale</span> applications, where the parameters need to be estimated on a regional area-wide basis. To gain more knowledge about challenges associated with the up-scaling of multi-variable flood loss <span class="hlt">models</span> the following approach is applied: Single- and multi-variable micro-scale flood loss <span class="hlt">models</span> are up-scaled and applied on the <span class="hlt">meso-scale</span>, namely on basis of ATKIS land-use units. Application and validation is undertaken in 19 municipalities, which were affected during the 2002 flood by the River Mulde in Saxony, Germany by comparison to official loss data provided by the Saxon Relief Bank (SAB).In the <span class="hlt">meso-scale</span> case study based <span class="hlt">model</span> validation, most multi-variable <span class="hlt">models</span> show smaller errors than the uni-variable stage-damage functions. The results show the suitability of the up-scaling approach, and, in accordance with micro-scale validation studies, that multi-variable <span class="hlt">models</span> are an improvement in flood loss <span class="hlt">modelling</span> also on the <span class="hlt">meso-scale</span>. However, uncertainties remain high, stressing the importance of uncertainty quantification. Thus, the development of probabilistic loss <span class="hlt">models</span>, like BT-FLEMO used in this study, which inherently provide uncertainty information are the way forward.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2010AGUFM.A51D0162Z','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2010AGUFM.A51D0162Z"><span id="translatedtitle"><span class="hlt">Nested</span>-grid <span class="hlt">Modeling</span> of Mercury Wet Deposition over the Southeast U.S</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Zhang, Y.; Jaegle, L.; Holmes, C.; Jacob, D. J.; van Donkelaar, A.; Martin, R. V.</p> <p>2010-12-01</p> <p>As a potent neurotoxin, atmospheric mercury (Hg) bioaccumulates in food webs and eventually affects human health once deposited to aquatic environment. The highest Hg wet deposition rates over the United States are observed in the Southeast, in states bordering the Gulf of Mexico. There are a number of conflicting explanations for these high deposition rates: some have proposed local urban emissions as the dominant source, while others have argued that Hg was scavenged from the global pool in the free troposphere. In this study, we will use the GEOS-Chem Hg simulation to examine the origin of wet deposition over the Southeast U.S. We have developed a <span class="hlt">nested</span> Hg-oxidant capability for the GEOS-Chem chemical transport <span class="hlt">model</span>, with a horizontal resolution of half degree latitude by two thirds degrees longitude over N. America. Boundary conditions are provided by a global simulation with coarser resolution (4 degrees by 5 degrees) but using the same emissions, chemistry, deposition, and meteorological fields. The <span class="hlt">model</span> uses bromine as the main oxidant for Hg. We will demonstrate how, compared with the global <span class="hlt">model</span>, the <span class="hlt">nested</span> <span class="hlt">model</span> shows improved skill at capturing the high spatial and temporal variability of Hg wet deposition over the Gulf region, especially in Florida. Over this region, wet deposition is driven by episodic convective precipitation occurring on small spatial scales. We will show that the wet Hg deposition flux of this region has both regional and global sources, but that the contribution from the global Hg pool is more important. We will examine how assumptions about chemistry, gas/particulate partitioning, emissions, and wet deposition affect our results.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2007AGUFM.H43I..06M&link_type=ABSTRACT','NASAADS'); return false;" href="http://adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2007AGUFM.H43I..06M&link_type=ABSTRACT"><span id="translatedtitle">Diagnosing coupled watershed processes using a fully-coupled groundwater, land-surface, surface water and <span class="hlt">mesoscale</span> atmospheric <span class="hlt">model</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Maxwell, R. M.; Kollet, S. J.; Chow, F. K.</p> <p>2007-12-01</p> <p>A variably-saturated groundwater flow <span class="hlt">model</span> with an integrated overland flow component, a land-surface <span class="hlt">model</span> and a <span class="hlt">mesoscale</span> atmospheric <span class="hlt">model</span> is used to examine the interplay between coupled water and energy processes. These processes are influenced by land-surface topography and subsurface heterogeneity. This parallel, integrated <span class="hlt">model</span> simulates spatial variations in land-surface forcing driven by three-dimensional (3D) atmospheric and subsurface components. Spatial statistics are used to demonstrate spatial and temporal correlations between surface and lower atmospheric variables and water table depth. These correlations are particularly strong during times when the land surface temperatures trigger shifts in wind behavior, such as during early morning surface heating. Additionally, spectral transforms of subsurface arrival times are computed using a transient Lagrangian transport simulation. Macrodispersion is used to mimic the effects of subsurface heterogeneity for a range of Peclet numbers. The slopes of these transforms indicate fractal scaling of this system over a range of timescales. All of these techniques point to importance of realistically representing coupled processes and the need to understand and diagnose these processes in nature. This work was conducted under the auspices of the U. S. Department of Energy by the University of California, Lawrence Livermore National Laboratory (LLNL) under contract W-7405-Eng-48. This project was funded by the Laboratory Directed Research and Development Program at LLNL</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015OcDyn..65..877Z','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015OcDyn..65..877Z"><span id="translatedtitle">High-resolution <span class="hlt">modeling</span> of the mean flow and <span class="hlt">meso-scale</span> eddy variability around the Grand Banks of Newfoundland</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Zhai, Li; Lu, Youyu; Higginson, Simon; Davidson, Fraser; Dupont, Frédéric; Roy, François; Chanut, Jérôme; Smith, Gregory C.</p> <p>2015-06-01</p> <p>The mean flow and <span class="hlt">meso-scale</span> eddy variability in the region around the Grand Banks of Newfoundland (GBN) are quantified by analyzing surface drifter observations, mean dynamic topography (MDT), along-track satellite altimeter observations, and the solutions of two high-resolution ocean <span class="hlt">models</span>. By increasing the horizontal resolution from 6.5 km (CREG12) to 2.2 km (GBN36), the <span class="hlt">modeled</span> mean kinetic energy (MKE) decreases and the eddy kinetic energy (EKE) increases in the study area. GBN36 obtains the MKE of surface geostrophic currents and total currents similar to that derived from MDT and drifter data, whereas CREG12 overestimates these quantities by 40-53 %. CREG12 and GBN36 underestimate the EKE of surface geostrophic currents by 46 and 30 %, respectively, with respect to the EKE derived from along-track altimeter data. The <span class="hlt">models</span> do not reproduce the strong eddy activity in the Gulf Stream and its downstream region, possibly related to a northward shift of the Gulf Stream position by 0.5° in latitude compared with observations. Both <span class="hlt">models</span> obtain wavenumber spectra of sea level anomaly in close agreement with the spectrum derived from along-track altimeter data, with a slope of -5 at wavelengths near 100 km on logarithmic spectral density scales.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015EGUGA..17.1651Z','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015EGUGA..17.1651Z"><span id="translatedtitle">High-resolution <span class="hlt">modelling</span> of the mean flow and <span class="hlt">meso-scale</span> eddy variability around the Grand Banks of Newfoundland</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Zhai, Li; Lu, Youyu; Higginson, Simon; Davidson, Fraser; Dupont, Fred; Roy, Francois; Chanut, Jerome; Smith, Greg</p> <p>2015-04-01</p> <p>The mean flow and <span class="hlt">meso-scale</span> eddy variability in the region around the Grand Banks of Newfoundland (GBN) are quantified by analyzing surface drifter observations, mean dynamic topography (MDT), along-track satellite altimeter observations and the solutions of two high-resolution ocean <span class="hlt">models</span> based on NEMO. By increasing the horizontal resolution from 6.5 km (CREG12) to 2.2 km (GBN36), the <span class="hlt">modelled</span> mean kinetic energy (MKE) decreases and the eddy kinetic energy (EKE) increases in the study area. GBN36 obtains the MKE of surface geostrophic currents and total currents similar to that derived from MDT and drifter data, whereas CREG12 overestimates these quantities by 40-53%. CREG12 and GBN36 underestimate the EKE of surface geostrophic currents by 46% and 30% respectively with respect to the EKE derived from along-track SLA data. The <span class="hlt">models</span> do not reproduce the strong eddy activity in the Gulf Stream and its downstream region, possibly related to a northward shift of the Gulf Stream position by 0.5° in latitude. Both <span class="hlt">models</span> obtain wavenumber spectra of sea level anomaly in close agreement with the spectrum derived from along-track altimeter data, with a slope of -5 at wavelengths near 100 km on logarithmic spectral density scales.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015IzAOP..51.1034C','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015IzAOP..51.1034C"><span id="translatedtitle">Cold-air outbreaks over the ocean at high latitudes and associated <span class="hlt">mesoscale</span> atmospheric circulations: Problems of numerical <span class="hlt">modelling</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Chechin, D. G.; Pichugin, M. K.</p> <p>2015-12-01</p> <p>A review of the current state of research in the field of numerical <span class="hlt">modelling</span> and forecasting of cold-air outbreaks over the ocean at high latitudes and associated <span class="hlt">mesoscale</span> circulations is presented. It is shown that the most relevant tasks are as follows: (1) the improvement of predictability and the adequacy of reproduction of polar mesocyclones, (2) a more adequate representation of the marginal sea-ice zone in the numerical <span class="hlt">models</span>, and (3) solving problems of the parametrization and explicit reproduction of organized convection and orographic jets in numerical atmosphere <span class="hlt">models</span>. It is demonstrated that these tasks only can be accomplished as a result of a comprehensive development of different components of the climatic system <span class="hlt">models</span> and technology of the numerical weather prediction (NWP). One of the most promising approaches to overcome the identified problems is to develop and use methods of satellite remote sensing of the atmosphere and underlying surface in NWP technology. The high potential of analyzing the satellite multisensor data for quantifying parameters of different-scale atmospheric circulations is demonstrated using the example of cold-air outbreaks over the seas of the Far East.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016BoLMe.159..589D','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016BoLMe.159..589D"><span id="translatedtitle">Assessment of Planetary Boundary-Layer Schemes in the Weather Research and Forecasting <span class="hlt">Mesoscale</span> <span class="hlt">Model</span> Using MATERHORN Field Data</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Dimitrova, Reneta; Silver, Zachariah; Zsedrovits, Tamas; Hocut, Christopher M.; Leo, Laura S.; Di Sabatino, Silvana; Fernando, Harindra J. S.</p> <p>2016-06-01</p> <p>The study was aimed at understanding the deficiencies of numerical <span class="hlt">mesoscale</span> <span class="hlt">models</span> by comparing predictions with a new high-resolution meteorological dataset collected during the Mountain Terrain Atmospheric <span class="hlt">Modelling</span> and Observations (MATERHORN) Program. The simulations focussed on the stable boundary layer (SBL), the predictions of which continue to be challenging. High resolution numerical simulations (0.5-km horizontal grid size) were conducted to investigate the efficacy of six planetary boundary-layer (PBL) parametrizations available in the advanced research version of the Weather Research and Forecasting <span class="hlt">model</span>. One of the commonly used PBL schemes was modified to include eddy diffusivities that account for enhanced momentum transport compared to heat transport in the SBL, representing internal wave dynamics. All of the tested PBL schemes, including the modified scheme, showed a positive surface temperature bias. None of the PBL schemes was found to be superior in predicting the vertical wind and temperature profiles over the lowest 500 m, however two of the schemes appeared superior in capturing the lower PBL structure. The lowest <span class="hlt">model</span> layers appear to have a significant impact on the predictions aloft. Regions of sporadic flow interactions delineated by the MATERHORN observations were poorly predicted, given such interactions are not represented in typical PBL schemes.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2013JSR....83...30G','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2013JSR....83...30G"><span id="translatedtitle">A comparison of primary production <span class="hlt">models</span> in an area of high <span class="hlt">mesoscale</span> variability (South Shetland Islands, Antarctica)</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>García-Muñoz, Cristina; López-Urrutia, Ángel; Lubián, Luis M.; García, Carlos M.; Hernández-León, Santiago</p> <p>2013-10-01</p> <p>Three types of primary productivity (PP) <span class="hlt">models</span> were evaluated in a <span class="hlt">mesoscale</span> area around the South Shetland Islands (Antarctica). Input variables were: phytoplankton carbon biomass, Chlorophyll a, sea water temperature, daily irradiance, among others, collected in situ during an oceanographic cruise (COUPLING, January 2010). <span class="hlt">Models</span> of the first type were based on Chl a measurements: the widely used <span class="hlt">model</span> VGPM (Behrenfeld and Falkowski, 1997) and a derived version developed for the Western Antarctic Peninsula (Dierssen et al., 2000). The second type included two <span class="hlt">models</span> based on phytoplankton carbon biomass: one developed for the whole Southern Ocean (Arrigo et al., 2008) and one based on the Metabolic Theory of Ecology developed by López-Urrutia et al. (2006), being the first time that a <span class="hlt">model</span> with these features is used for Antarctic waters. The third type was an updated version of the carbon-based <span class="hlt">model</span> CbPM (first described by Behrenfeld et al. (2005)) based on the Chl a/carbon biomass ratio modulation. The degree of agreement among the results between the different types of <span class="hlt">models</span> turned out to be low (> 30% of difference), but high within <span class="hlt">models</span> of the same type (< 10% of difference). Biomass-based <span class="hlt">model</span> predictions differed the most from those estimated by the other two types. The differences in PP estimates were primarily attributed to the different ways these <span class="hlt">models</span> treat the phytoplankton assemblage, along with the difference in input variables. Among the five <span class="hlt">models</span> evaluated, the output from the modified version of the CbPM showed the lowest bias (0.55) being the most realistic. It made a special attempt to detect the factors controlling phytoplankton physiological state, showing a nutrient limitation towards the Drake area similar to the one observed for the in situ PP values.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://ntrs.nasa.gov/search.jsp?R=19920000674&hterms=cybernetics&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D80%26Ntt%3Dcybernetics','NASA-TRS'); return false;" href="http://ntrs.nasa.gov/search.jsp?R=19920000674&hterms=cybernetics&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D80%26Ntt%3Dcybernetics"><span id="translatedtitle"><span class="hlt">Nested</span> Neural Networks</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Baram, Yoram</p> <p>1992-01-01</p> <p>Report presents analysis of <span class="hlt">nested</span> neural networks, consisting of interconnected subnetworks. Analysis based on simplified mathematical <span class="hlt">models</span> more appropriate for artificial electronic neural networks, partly applicable to biological neural networks. <span class="hlt">Nested</span> structure allows for retrieval of individual subpatterns. Requires fewer wires and connection devices than fully connected networks, and allows for local reconstruction of damaged subnetworks without rewiring entire network.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014AGUFMOS51A0955R','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014AGUFMOS51A0955R"><span id="translatedtitle">Development of a triply <span class="hlt">nested</span> eddy resolving north Indian Ocean <span class="hlt">model</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Rahaman, H.; Harrison, M.</p> <p>2014-12-01</p> <p>High resolution triply <span class="hlt">nested</span> eddy resolving regional Indian Ocean <span class="hlt">model</span> has been developed using recent version of Modular Ocean <span class="hlt">Model</span> (MOM4p1). A multi-<span class="hlt">model</span> approach is adopted using MOM4p1 and INCOIS-GODAS. In this setup, regional <span class="hlt">model</span> (IOM-1/4) in the Indian Ocean region with 1/4° (~ 25 km) horizontal resolution (eddy permitting) and less than 1 meter vertical resolution in the near the surface, takes initial and lateral boundary condition from INCOIS-GODAS. IOM-1/4 solutions are then used to give lateral boundary condition to an eddy resolving (1/12° horizontal resolution) north Indian Ocean <span class="hlt">Model</span> (IOM-1/12). The physics in eddy permitting and eddy resolving <span class="hlt">model</span> is same. The forcing is same in all three <span class="hlt">model</span> simulations. The analysis of <span class="hlt">model</span> solutions during January 2010 to June 2013 shows significant improvement in upper ocean variability in IOM-12 as compared to INCOIS-GODAS and IOM-1/4. The costal currents along the Indian coast are more realistic in eddy resolving MOM-1/12 as compared to MOM-1/4 and INCOIS-GODAS.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/servlets/purl/1235292','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/servlets/purl/1235292"><span id="translatedtitle">Top-down estimate of methane emissions in California using a <span class="hlt">mesoscale</span> inverse <span class="hlt">modeling</span> technique: The South Coast Air Basin</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Cui, Yu Yan; Brioude, Jerome; McKeen, Stuart A.; Angevine, Wayne M.; Kim, Si -Wan; Frost, Gregory J.; Ahmadov, Ravan; Peischl, Jeff; Bousserez, Nicolas; Liu, Zhen; Ryerson, Thomas B.; Wofsy, Steve C.; Santoni, Gregory W.; Kort, Eric A.; Fischer, Marc L.; Trainer, Michael</p> <p>2015-07-28</p> <p>Methane (CH<sub>4</sub>) is the primary component of natural gas and has a larger global warming potential than CO<sub>2</sub>. Some recent top-down studies based on observations showed CH<sub>4</sub> emissions in California's South Coast Air Basin (SoCAB) were greater than those expected from population-apportioned bottom-up state inventories. In this study, we quantify CH<sub>4 </sub>emissions with an advanced <span class="hlt">mesoscale</span> inverse <span class="hlt">modeling</span> system at a resolution of 8 km × 8 km, using aircraft measurements in the SoCAB during the 2010 Nexus of Air Quality and Climate Change campaign to constrain the inversion. To simulate atmospheric transport, we use the FLEXible PARTicle-Weather Research and Forecasting (FLEXPART-WRF) Lagrangian particle dispersion <span class="hlt">model</span> driven by three configurations of the Weather Research and Forecasting (WRF) <span class="hlt">mesoscale</span> <span class="hlt">model</span>. We determine surface fluxes of CH<sub>4</sub> using a Bayesian least squares method in a four-dimensional inversion. Simulated CH4 concentrations with the posterior emission inventory achieve much better correlations with the measurements (R2 = 0.7) than using the prior inventory (U.S. Environmental Protection Agency's National Emission Inventory 2005, R<sup>2</sup> = 0.5). The emission estimates for CH<sub>4</sub> in the posterior, 46.3 ± 9.2 Mg CH<sub>4</sub>/h, are consistent with published observation-based estimates. Changes in the spatial distribution of CH<sub>4</sub> emissions in the SoCAB between the prior and posterior inventories are discussed. Missing or underestimated emissions from dairies, the oil/gas system, and landfills in the SoCAB seem to explain the differences between the prior and posterior inventories. Furthermore, we estimate that dairies contributed 5.9 ± 1.7 Mg CH<sub>4</sub>/h and the two sectors of oil and gas industries (production and downstream) and landfills together contributed 39.6 ± 8.1 Mg CH<sub>4</sub>/h in the SoCAB.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014AGUFM.A23H3344V','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014AGUFM.A23H3344V"><span id="translatedtitle">The <span class="hlt">mesoscale</span> precipitation distribution in mid-latitude continental regions: observational uncertainty and evaluation of 25-km global <span class="hlt">model</span> simulations.</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Vidale, P. L.; Schiemann, R.; Demory, M. E.; Roberts, C. J.</p> <p>2014-12-01</p> <p>Mid-latitude precipitation over land exhibits a high degree of variability due to the complex interaction of governing atmospheric processes with coastlines, the heterogeneous land surface, and orography. General circulation <span class="hlt">models</span> (GCMs) have traditionally shown limited ability in capturing variability in the <span class="hlt">mesoscale</span> range (here ~50-500 km), due to their low resolution. Recent advances in resolution have provided ensembles of multidecadal climate simulations with GCMs using ~25 km grid spacing. Here, we assess this class of GCM simulations, from the UPSCALE (UK on PrACE - weather-resolving Simulations of Climate for globAL Environmental risk) campaign. Increased <span class="hlt">model</span> resolution also poses new challenges to the observational datasets used to evaluate <span class="hlt">models</span>. Global gridded data products (e.g. from the Global Precipitation Climatology Project, GPCP) are invaluable for assessing large-scale precipitation features, but may not sufficiently resolve <span class="hlt">mesoscale</span> structures. In the absence of alternative estimates, the intercomparison of specialised, regional observational datasets may be the only way to gain insight into the uncertainties associated with these observations. We focus on three mid-latitude continental regions where gridded precipitation observations based on higher-density gauge networks are available, complementing the global data sets: Europe (with a particular emphasis on the Alps), South and East Asia, and the continental US. Additional motivation, and opportunity, arises from continuing efforts to quantify the components of the global radiation budget and water cycle. Recent estimates based on radiation measurements suggest that the global mean precipitation/evaporation may be up to 10 Wm-2 (about 0.35 mm day-1) larger than the estimate obtained from GPCP. While the main part of this discrepancy is thought to be due to the underestimation of remotely-sensed ocean precipitation, there is also considerable uncertainty about 'unobserved' precipitation</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015PhDT.......153L','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015PhDT.......153L"><span id="translatedtitle">Permeability of fiber reinforcements for liquid composite molding: Sequential multi-scale investigations into numerical flow <span class="hlt">modeling</span> on the micro- and <span class="hlt">meso-scale</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Luchini, Timothy John Franklin</p> <p></p> <p>Composites are complex material mixtures, known to have high amounts of variability, with unique properties at the micro-, meso-, and macro-scales. In the context of advanced textile composite reinforcements, micro-scale refers to aligned fibers and toughening agents in a disordered arrangement; <span class="hlt">meso-scale</span> is the woven, braided, or stitched fabric geometry (which compacts to various volume fractions); and macro-scale is the component or sub-component being produced for a mechanical application. The Darcy-based permeability is an important parameter for <span class="hlt">modeling</span> and understanding the flow profile and fill times for liquid composite molding. Permeability of composite materials can vary widely from the micro- to macro-scales. For example, geometric factors like compaction and ply layup affect the component permeability at the meso- and macro-scales. On the micro-scale the permeability will be affected by the packing arrangement of the fibers and fiber volume fraction. On any scale, simplifications to the geometry can be made to treat the fiber reinforcement as a porous media. Permeability has been widely studied in both experimental and analytical frameworks, but less attention has focused on the ability of numerical tools to predict the permeability of reinforced composite materials. This work aims at (1) predicting permeability at various scales of interest and (2) developing a sequential, multi-scale, numerical <span class="hlt">modeling</span> approach on the micro- and <span class="hlt">meso-scales</span>. First, a micro-scale <span class="hlt">modeling</span> approach is developed, including a geometry generation tool and a fluids-based numerical permeability solver. This micro-scale <span class="hlt">model</span> included all physical fibers and derived the empirical permeability constant directly though numerical simulation. This numerical approach was compared with literature results for perfect packing arrangements, and the results were shown to be comparable with previous work. The numerical simulations described here also extended these previous</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015EGUGA..17.6441T','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015EGUGA..17.6441T"><span id="translatedtitle">Simulation of Storm Surge by a Depth-integrated Non-hydrostatic <span class="hlt">Nested</span>-gird <span class="hlt">Model</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Tsai, Yu-Lin; Wu, Tso-Ren; Terng, Chuen-Teyr; Cheung, Mei-Hui</p> <p>2015-04-01</p> <p>This paper presents COMCOT-SS (COrnell Multi-grid Coupled of Tsunami <span class="hlt">Model</span> - Storm Surge) operational <span class="hlt">model</span>, a depth integrated non-hydrostatic storm surge <span class="hlt">model</span> developed for the Central Weather Bureau (CWB) in Taiwan. This <span class="hlt">model</span> is based on the widely-validated COMCOT tsunami <span class="hlt">model</span>. However, the governing equations were modified to be a depth-integrated vertical momentum equation, and the nonlinear shallow water equations including extra terms, such as the non-hydrostatic pressure, weather forcing, and tidal terms. The non-hydrostatic term enables the <span class="hlt">model</span> to simulate relatively steep waves in the near-shore region. The conventional features in COMCOT, such as the <span class="hlt">nested</span>-grid system, spherical and Cartesian coordinate systems, and the moving boundary scheme for inundation prediction were preserved. In this study, we carefully validated the <span class="hlt">model</span> with analytic solutions for wind shear stress and pressure gradient terms. TWRF (Typhoon Weather Research and Forecasting) <span class="hlt">model</span> was coupled for providing the meteorological forces generated by typhoons. Besides, parametric typhoon <span class="hlt">models</span> such as Holland <span class="hlt">model</span> (1980) and CWB <span class="hlt">model</span> were also coupled with COMCOT-SS in which the drag coefficient was advised by Large and Pond (1981) and Powell (2003). Astronomical tide provided by the TPXO global tidal <span class="hlt">model</span> was imported from the domain boundaries. As for the <span class="hlt">model</span> performance, COMCOT-SS spends less than 30 minutes to finish a 48-hrs forecasting with a large computational domain which covers Taiwan Strait and most parts of Western Pacific Ocean and South China Sea and satisfies the requirement of early warning. In this paper, we also presented the results of nine typical typhoon routes defined by CWB in Taiwan for the <span class="hlt">model</span> verification. The simulation results accompanied with the non-hydrostatic effect presented good agreement with observation data. Detailed results and discussion will be presented in EGU, 2015.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2015EGUGA..17.7162M&link_type=ABSTRACT','NASAADS'); return false;" href="http://adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2015EGUGA..17.7162M&link_type=ABSTRACT"><span id="translatedtitle"><span class="hlt">Nested</span> 1D-2D approach for urban surface flood <span class="hlt">modeling</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Murla, Damian; Willems, Patrick</p> <p>2015-04-01</p> <p>Floods in urban areas as a consequence of sewer capacity exceedance receive increased attention because of trends in urbanization (increased population density and impermeability of the surface) and climate change. Despite the strong recent developments in numerical <span class="hlt">modeling</span> of water systems, urban surface flood <span class="hlt">modeling</span> is still a major challenge. Whereas very advanced and accurate flood <span class="hlt">modeling</span> systems are in place and operation by many river authorities in support of flood management along rivers, this is not yet the case in urban water management. Reasons include the small scale of the urban inundation processes, the need to have very high resolution topographical information available, and the huge computational demands. Urban drainage related inundation <span class="hlt">modeling</span> requires a 1D full hydrodynamic <span class="hlt">model</span> of the sewer network to be coupled with a 2D surface flood <span class="hlt">model</span>. To reduce the computational times, 0D (flood cones), 1D/quasi-2D surface flood <span class="hlt">modeling</span> approaches have been developed and applied in some case studies. In this research, a <span class="hlt">nested</span> 1D/2D hydraulic <span class="hlt">model</span> has been developed for an urban catchment at the city of Gent (Belgium), linking the underground sewer (minor system) with the overland surface (major system). For the overland surface flood <span class="hlt">modelling</span>, comparison was made of 0D, 1D/quasi-2D and full 2D approaches. The approaches are advanced by considering <span class="hlt">nested</span> 1D-2D approaches, including infiltration in the green city areas, and allowing the effects of surface storm water storage to be simulated. An optimal <span class="hlt">nested</span> combination of three different mesh resolutions was identified; based on a compromise between precision and simulation time for further real-time flood forecasting, warning and control applications. Main streets as mesh zones together with buildings as void regions constitute one of these mesh resolution (3.75m2 - 15m2); they have been included since they channel most of the flood water from the manholes and they improve the accuracy of</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_19");'>19</a></li> <li><a href="#" onclick='return showDiv("page_20");'>20</a></li> <li class="active"><span>21</span></li> <li><a href="#" onclick='return showDiv("page_22");'>22</a></li> <li><a href="#" onclick='return showDiv("page_23");'>23</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_21 --> <div id="page_22" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_20");'>20</a></li> <li><a href="#" onclick='return showDiv("page_21");'>21</a></li> <li class="active"><span>22</span></li> <li><a href="#" onclick='return showDiv("page_23");'>23</a></li> <li><a href="#" onclick='return showDiv("page_24");'>24</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="421"> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3858107','PMC'); return false;" href="http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3858107"><span id="translatedtitle">Causal Inference in Occupational Epidemiology: Accounting for the Healthy Worker Effect by Using Structural <span class="hlt">Nested</span> <span class="hlt">Models</span></span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Naimi, Ashley I.; Richardson, David B.; Cole, Stephen R.</p> <p>2013-01-01</p> <p>In a recent issue of the Journal, Kirkeleit et al. (Am J Epidemiol. 2013;177(11):1218–1224) provided empirical evidence for the potential of the healthy worker effect in a large cohort of Norwegian workers across a range of occupations. In this commentary, we provide some historical context, define the healthy worker effect by using causal diagrams, and use simulated data to illustrate how structural <span class="hlt">nested</span> <span class="hlt">models</span> can be used to estimate exposure effects while accounting for the healthy worker survivor effect in 4 simple steps. We provide technical details and annotated SAS software (SAS Institute, Inc., Cary, North Carolina) code corresponding to the example analysis in the Web Appendices, available at http://aje.oxfordjournals.org/. PMID:24077092</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://pubs.er.usgs.gov/publication/70047815','USGSPUBS'); return false;" href="http://pubs.er.usgs.gov/publication/70047815"><span id="translatedtitle">Increased flexibility for <span class="hlt">modeling</span> telemetry and <span class="hlt">nest</span>-survival data using the multistate framework</span></a></p> <p><a target="_blank" href="http://pubs.er.usgs.gov/pubs/index.jsp?view=adv">USGS Publications Warehouse</a></p> <p>Devineau, Olivier; Kendall, William L.; Doherty, Paul F., Jr.; Shenk, Tanya M.; White, Gary C.; Lukacs, Paul M.; Burnham, Kenneth P.</p> <p>2014-01-01</p> <p>Although telemetry is one of the most common tools used in the study of wildlife, advances in the analysis of telemetry data have lagged compared to progress in the development of telemetry devices. We demonstrate how standard known-fate telemetry and related <span class="hlt">nest</span>-survival data analysis <span class="hlt">models</span> are special cases of the more general multistate framework. We present a short theoretical development, and 2 case examples regarding the American black duck and the mallard. We also present a more complex lynx data analysis. Although not necessary in all situations, the multistate framework provides additional flexibility to analyze telemetry data, which may help analysts and biologists better deal with the vagaries of real-world data collection.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://eric.ed.gov/?q=Nests&pg=6&id=EJ666919','ERIC'); return false;" href="http://eric.ed.gov/?q=Nests&pg=6&id=EJ666919"><span id="translatedtitle">Triangular <span class="hlt">Nests</span>!</span></a></p> <p><a target="_blank" href="http://www.eric.ed.gov/ERICWebPortal/search/extended.jsp?_pageLabel=advanced">ERIC Educational Resources Information Center</a></p> <p>Powell, R. I.</p> <p>2002-01-01</p> <p>Shows how integer-sided triangles can be <span class="hlt">nested</span>, each <span class="hlt">nest</span> having a single enclosing isosceles triangle. Brings to light what can be seen as a relatively simple generalization of Pythagoras' theorem, a result that should be readily accessible to many secondary school pupils. (Author/KHR)</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2016EGUGA..1812793N&link_type=ABSTRACT','NASAADS'); return false;" href="http://adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2016EGUGA..1812793N&link_type=ABSTRACT"><span id="translatedtitle">Streamflow hindcasting in European river basins via multi-parametric ensemble of the <span class="hlt">mesoscale</span> hydrologic <span class="hlt">model</span> (mHM)</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Noh, Seong Jin; Rakovec, Oldrich; Kumar, Rohini; Samaniego, Luis</p> <p>2016-04-01</p> <p>There have been tremendous improvements in distributed hydrologic <span class="hlt">modeling</span> (DHM) which made a process-based simulation with a high spatiotemporal resolution applicable on a large spatial scale. Despite of increasing information on heterogeneous property of a catchment, DHM is still subject to uncertainties inherently coming from <span class="hlt">model</span> structure, parameters and input forcing. Sequential data assimilation (DA) may facilitate improved streamflow prediction via DHM using real-time observations to correct internal <span class="hlt">model</span> states. In conventional DA methods such as state updating, parametric uncertainty is, however, often ignored mainly due to practical limitations of methodology to specify <span class="hlt">modeling</span> uncertainty with limited ensemble members. If parametric uncertainty related with routing and runoff components is not incorporated properly, predictive uncertainty by DHM may be insufficient to capture dynamics of observations, which may deteriorate predictability. Recently, a multi-scale parameter regionalization (MPR) method was proposed to make hydrologic predictions at different scales using a same set of <span class="hlt">model</span> parameters without losing much of the <span class="hlt">model</span> performance. The MPR method incorporated within the <span class="hlt">mesoscale</span> hydrologic <span class="hlt">model</span> (mHM, http://www.ufz.de/mhm) could effectively represent and control uncertainty of high-dimensional parameters in a distributed <span class="hlt">model</span> using global parameters. In this study, we present a global multi-parametric ensemble approach to incorporate parametric uncertainty of DHM in DA to improve streamflow predictions. To effectively represent and control uncertainty of high-dimensional parameters with limited number of ensemble, MPR method is incorporated with DA. Lagged particle filtering is utilized to consider the response times and non-Gaussian characteristics of internal hydrologic processes. The hindcasting experiments are implemented to evaluate impacts of the proposed DA method on streamflow predictions in multiple European river basins</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014PhDT........60W','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014PhDT........60W"><span id="translatedtitle">A unified bond theory, probabilistic <span class="hlt">meso-scale</span> <span class="hlt">modeling</span>, and experimental validation of deformed steel rebar in normal strength concrete</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Wu, Chenglin</p> <p></p> <p>Bond between deformed rebar and concrete is affected by rebar deformation pattern, concrete properties, concrete confinement, and rebar-concrete interfacial properties. Two distinct groups of bond <span class="hlt">models</span> were traditionally developed based on the dominant effects of concrete splitting and near-interface shear-off failures. Their accuracy highly depended upon the test data sets selected in analysis and calibration. In this study, a unified bond <span class="hlt">model</span> is proposed and developed based on an analogy to the indentation problem around the rib front of deformed rebar. This mechanics-based <span class="hlt">model</span> can take into account the combined effect of concrete splitting and interface shear-off failures, resulting in average bond strengths for all practical scenarios. To understand the fracture process associated with bond failure, a probabilistic <span class="hlt">meso-scale</span> <span class="hlt">model</span> of concrete is proposed and its sensitivity to interface and confinement strengths are investigated. Both the mechanical and finite element <span class="hlt">models</span> are validated with the available test data sets and are superior to existing <span class="hlt">models</span> in prediction of average bond strength (< 6% error) and crack spacing (< 6% error). The validated bond <span class="hlt">model</span> is applied to derive various interrelations among concrete crushing, concrete splitting, interfacial behavior, and the rib spacing-to-height ratio of deformed rebar. It can accurately predict the transition of failure modes from concrete splitting to rebar pullout and predict the effect of rebar surface characteristics as the rib spacing-to-height ratio increases. Based on the unified theory, a global bond <span class="hlt">model</span> is proposed and developed by introducing bond-slip laws, and validated with testing of concrete beams with spliced reinforcement, achieving a load capacity prediction error of less than 26%. The optimal rebar parameters and concrete cover in structural designs can be derived from this study.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2013APS..DFDA12005O','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2013APS..DFDA12005O"><span id="translatedtitle"><span class="hlt">Nested</span> contour-dynamic <span class="hlt">models</span> for axisymmetric vortex rings and vortex wakes</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>O'Farrell, Clara; Dabiri, John O.</p> <p>2013-11-01</p> <p>Jetting swimmers, such as squid and jellyfish, propel themselves by forming vortex rings. It is known that vortex rings cannot grow indefinitely, but rather ``pinch off'' once they reach their physical limit, and that a decrease in efficiency of fluid transport is associated with pinch-off. Previously, the Norbury family of vortices has been used as a <span class="hlt">model</span> for axisymmetric vortex rings, and the response of this family to shape perturbations has been characterized. We improve upon the Norbury <span class="hlt">models</span>, using <span class="hlt">nested</span> patches of vorticity to construct a family of <span class="hlt">models</span> for vortex rings generated by a piston-cylinder apparatus at different stroke ratios. The perturbation response of this family is considered by the introduction of a small region of vorticity at the rear of the vortex, which mimics the addition of circulation to a growing vortex ring by a feeding shear layer. <span class="hlt">Model</span> vortex rings are found to either accept the additional circulation or shed it into a tail, depending on the perturbation size. A change in the behavior of the <span class="hlt">model</span> vortex rings is identified at a stroke ratio of three. We hypothesize that this change in response is analogous to pinch-off, and that pinch-off might be understood and predicted based on the perturbation responses of <span class="hlt">model</span> vortex rings.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015PApGe.172.3455B','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015PApGe.172.3455B"><span id="translatedtitle">Parallel Implementation of Dispersive Tsunami Wave <span class="hlt">Modeling</span> with a <span class="hlt">Nesting</span> Algorithm for the 2011 Tohoku Tsunami</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Baba, Toshitaka; Takahashi, Narumi; Kaneda, Yoshiyuki; Ando, Kazuto; Matsuoka, Daisuke; Kato, Toshihiro</p> <p>2015-12-01</p> <p>Because of improvements in offshore tsunami observation technology, dispersion phenomena during tsunami propagation have often been observed in recent tsunamis, for example the 2004 Indian Ocean and 2011 Tohoku tsunamis. The dispersive propagation of tsunamis can be simulated by use of the Boussinesq <span class="hlt">model</span>, but the <span class="hlt">model</span> demands many computational resources. However, rapid progress has been made in parallel computing technology. In this study, we investigated a parallelized approach for dispersive tsunami wave <span class="hlt">modeling</span>. Our new parallel software solves the nonlinear Boussinesq dispersive equations in spherical coordinates. A variable <span class="hlt">nested</span> algorithm was used to increase spatial resolution in the target region. The software can also be used to predict tsunami inundation on land. We used the dispersive tsunami <span class="hlt">model</span> to simulate the 2011 Tohoku earthquake on the Supercomputer K. Good agreement was apparent between the dispersive wave <span class="hlt">model</span> results and the tsunami waveforms observed offshore. The finest bathymetric grid interval was 2/9 arcsec (approx. 5 m) along longitude and latitude lines. Use of this grid simulated tsunami soliton fission near the Sendai coast. Incorporating the three-dimensional shape of buildings and structures led to improved <span class="hlt">modeling</span> of tsunami inundation.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2002EGSGA..27.5698M','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2002EGSGA..27.5698M"><span id="translatedtitle">Observations and <span class="hlt">Modelling</span> of Stream Flow and Stream Phosphorus In Four <span class="hlt">Nested</span> Grassland Catchments</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Moynihan, D.; Horgan, F.; Kiely, G.; Scanlon, T.</p> <p></p> <p>The ability to monitor and <span class="hlt">model</span> the physical and chemical dynamics of stream catchments has become of major importance over the past few years. There is now a greater awareness of the adverse affects of excess phosphorus concentrations on stream water quality and consequently more attention is being focused on the implementation of <span class="hlt">models</span> to trace and predict the paths of surface and subsurface flow which aid in agri-chemical transport. One such <span class="hlt">model</span> is Topmodel (a topography based hydrological <span class="hlt">model</span>) Beven et al. (2000). For a grassland catchment in Ireland a modified version of topmodel is used to simulate the observed catchment dynamics by deriving relationships from the integration of <span class="hlt">modelled</span> hydrological processes with observed hydrochemical data. Water quality and continuous flow data collected from four <span class="hlt">nested</span> catchments (15ha, 25ha, 2km2, 15km2) is <span class="hlt">modelled</span>. The effect of scale was also examined. A linear relationship holds between the flow at catchment 1 (15ha) and catchment 2 (25ha), but the scale effect between the larger areas is non ­ linear and dependent on the hydrological, vegetation and soil parameters. Topmodel is shown to simulate the hydrology well, but less accurate for the phosphorous.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/20100032010','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20100032010"><span id="translatedtitle">Predicting Tropical Cyclogenesis with a Global <span class="hlt">Mesoscale</span> <span class="hlt">Model</span>: Hierarchical Multiscale Interactions During the Formation of Tropical Cyclone Nargis(2008)</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Shen, B.-W.; Tao, W.-K.; Lau, W. K.; Atlas, R.</p> <p>2010-01-01</p> <p>Very severe cyclonic storm Nargis devastated Burma (Myanmar) in May 2008, caused tremendous damage and numerous fatalities, and became one of the 10 deadliest tropical cyclones (TCs) of all time. To increase the warning time in order to save lives and reduce economic damage, it is important to extend the lead time in the prediction of TCs like Nargis. As recent advances in high-resolution global <span class="hlt">models</span> and supercomputing technology have shown the potential for improving TC track and intensity forecasts, the ability of a global <span class="hlt">mesoscale</span> <span class="hlt">model</span> to predict TC genesis in the Indian Ocean is examined in this study with the aim of improving simulations of TC climate. High-resolution global simulations with real data show that the initial formation and intensity variations of TC Nargis can be realistically predicted up to 5 days in advance. Preliminary analysis suggests that improved representations of the following environmental conditions and their hierarchical multiscale interactions were the key to achieving this lead time: (1) a westerly wind burst and equatorial trough, (2) an enhanced monsoon circulation with a zero wind shear line, (3) good upper-level outflow with anti-cyclonic wind shear between 200 and 850 hPa, and (4) low-level moisture convergence.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4214118','PMC'); return false;" href="http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4214118"><span id="translatedtitle"><span class="hlt">Mesoscale</span> <span class="hlt">Model</span> to Select the Ideal Location for New Vineyard Plantations in the Rioja Qualified Denomination of Origin</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Martínez-Cámara, E.; Blanco, J.; Jiménez, E.; Saenz-Díez, J. C.; Rioja, J.</p> <p>2014-01-01</p> <p>La Rioja is the region where the top rated wines from Spain come from and also the origin of one of the most prestigious wines in the world. It is worldwide recognized, not only for the quality of the vine, but also for the many factors involved in the process that are controllable by the farmer, such as fertilizers, irrigation, etc. Likewise, there are other key factors, which cannot be controlled that play, however, a crucial role in the quality of the wine, such as temperature, radiation, humidity, and rainfall. This research is focused on two of these factors: temperature and irradiation. The objective of this paper is to be able to recognize these factors, so as to ensure a proper decision criterion when selecting the best location for new vineyard plantations. To achieve this objective, a <span class="hlt">mesoscale</span> <span class="hlt">model</span> MM5 is used, and its performance is assessed and compared using different parameters, from the grid resolution to the physical parameterization of the <span class="hlt">model</span>. Finally, the study evaluates the impact of the different parameterizations and options for the simulation of meteorological variables particularly relevant when choosing new vineyard sites (rainfall frequency, temperature, and sun exposure). PMID:25386596</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/25386596','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/25386596"><span id="translatedtitle"><span class="hlt">Mesoscale</span> <span class="hlt">model</span> to select the ideal location for new vineyard plantations in the Rioja qualified denomination of origin.</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Martínez-Cámara, E; Blanco, J; Jiménez, E; Saenz-Díez, J C; Rioja, J</p> <p>2014-01-01</p> <p>La Rioja is the region where the top rated wines from Spain come from and also the origin of one of the most prestigious wines in the world. It is worldwide recognized, not only for the quality of the vine, but also for the many factors involved in the process that are controllable by the farmer, such as fertilizers, irrigation, etc. Likewise, there are other key factors, which cannot be controlled that play, however, a crucial role in the quality of the wine, such as temperature, radiation, humidity, and rainfall. This research is focused on two of these factors: temperature and irradiation. The objective of this paper is to be able to recognize these factors, so as to ensure a proper decision criterion when selecting the best location for new vineyard plantations. To achieve this objective, a <span class="hlt">mesoscale</span> <span class="hlt">model</span> MM5 is used, and its performance is assessed and compared using different parameters, from the grid resolution to the physical parameterization of the <span class="hlt">model</span>. Finally, the study evaluates the impact of the different parameterizations and options for the simulation of meteorological variables particularly relevant when choosing new vineyard sites (rainfall frequency, temperature, and sun exposure). PMID:25386596</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014AGUFM.A51F3103E','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014AGUFM.A51F3103E"><span id="translatedtitle">Sensitivity of summer ensembles of super-parameterized US <span class="hlt">mesoscale</span> convective systems to cloud resolving <span class="hlt">model</span> microphysics and resolution</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Elliott, E.; Yu, S.; Kooperman, G. J.; Morrison, H.; Wang, M.; Pritchard, M. S.</p> <p>2014-12-01</p> <p>Microphysical and resolution sensitivities of explicitly resolved convection within <span class="hlt">mesoscale</span> convective systems (MCSs) in the central United States are well documented in the context of single case studies simulated by cloud resolving <span class="hlt">models</span> (CRMs) under tight boundary and initial condition constraints. While such an experimental design allows researchers to causatively isolate the effects of CRM microphysical and resolution parameterizations on <span class="hlt">modeled</span> MCSs, it is still challenging to produce conclusions generalizable to multiple storms. The uncertainty associated with the results of such experiments comes both from the necessary physical constraints imposed by the limited CRM domain as well as the inability to evaluate or control <span class="hlt">model</span> internal variability. A computationally practical method to minimize these uncertainties is the use of super-parameterized (SP) global climate <span class="hlt">models</span> (GCMs), in which CRMs are embedded within GCMs to allow their free interaction with one another as orchestrated by large-scale global dynamics. This study uses NCAR's SP Community Atmosphere <span class="hlt">Model</span> 5 (SP-CAM5) to evaluate microphysical and horizontal resolution sensitivities in summer ensembles of nocturnal MCSs in the central United States. Storm events within each run were identified using an objective empirical orthogonal function (EOF) algorithm, then further calibrated to harmonize individual storm signals and account for the temporal and spatial heterogeneity between them. Three summers of control data from a baseline simulation are used to assess <span class="hlt">model</span> internal interannual variability to measure its magnitude relative to sensitivities in a number of distinct experimental runs with varying CRM parameters. Results comparing sensitivities of convective intensity to changes in fall speed assumptions about dense rimed species, one- vs. two-moment microphysics, and CRM horizontal resolution will be discussed.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/biblio/6391936','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/biblio/6391936"><span id="translatedtitle">Transformed shoreline-following horizontal coordinates in a <span class="hlt">mesoscale</span> <span class="hlt">model</span>: A sea-land-breeze case study</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Berri, G.J.; Nunez, M.N. Pabellon II Ciudad Universitaria, Buenos Aires )</p> <p>1993-05-01</p> <p>A hydrostatic and incompressible <span class="hlt">mesoscale</span> <span class="hlt">model</span> with transformed horizontal coordinates is presented. The <span class="hlt">model</span> is applied to study the sea-land-breeze circulation over Rio de La Plata. One of the new coordinates is shoreline-following and the other one is locally quasi-perpendicular to the first one. The original set of equations in the Cartesian coordinates is rewritten in the curvilinear coordinates. This transformation is useful provided that the curvilinear coordinates are close to being orthogonal. The horizontal domain covers 250 km [times] 250 km, and the vertical domain is 2 km deep. To predict the sea-land-breeze circulation the <span class="hlt">model</span> is integrated over 12 h. The forcing of the <span class="hlt">model</span> is a cyclic perturbation of the surface temperature. The changes in the wind direction during the day are in good agreement with the observations from six weather stations in the region. The same program code is applied to uniform domains of different resolutions in order to test the coordinate transformation. Results show that the predictions based upon the variable-resolution version resemble ones obtained using high uniform resolution but consume only one-fourth the computer time needed by the latter. Comparison of the vertical velocity patterns predicted by the <span class="hlt">model</span> to the cumulus clouds distribution observed from satellite images show a very good agreement too. The authors believe that all these results justify the use of the coordinate transformation in this type of <span class="hlt">model</span>, although further verifications are needed in order to draw more definitive conclusions. 28 refs., 11 figs.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/19970023066','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19970023066"><span id="translatedtitle">Workstation-Based Real-Time <span class="hlt">Mesoscale</span> <span class="hlt">Modeling</span> Designed for Weather Support to Operations at the Kennedy Space Center and Cape Canaveral Air Station</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Manobianco, John; Zack, John W.; Taylor, Gregory E.</p> <p>1996-01-01</p> <p>This paper describes the capabilities and operational utility of a version of the <span class="hlt">Mesoscale</span> Atmospheric Simulation System (MASS) that has been developed to support operational weather forecasting at the Kennedy Space Center (KSC) and Cape Canaveral Air Station (CCAS). The implementation of local, <span class="hlt">mesoscale</span> <span class="hlt">modeling</span> systems at KSC/CCAS is designed to provide detailed short-range (less than 24 h) forecasts of winds, clouds, and hazardous weather such as thunderstorms. Short-range forecasting is a challenge for daily operations, and manned and unmanned launches since KSC/CCAS is located in central Florida where the weather during the warm season is dominated by <span class="hlt">mesoscale</span> circulations like the sea breeze. For this application, MASS has been modified to run on a Stardent 3000 workstation. Workstation-based, real-time numerical <span class="hlt">modeling</span> requires a compromise between the requirement to run the system fast enough so that the output can be used before expiration balanced against the desire to improve the simulations by increasing resolution and using more detailed physical parameterizations. It is now feasible to run high-resolution <span class="hlt">mesoscale</span> <span class="hlt">models</span> such as MASS on local workstations to provide timely forecasts at a fraction of the cost required to run these <span class="hlt">models</span> on mainframe supercomputers. MASS has been running in the Applied Meteorology Unit (AMU) at KSC/CCAS since January 1994 for the purpose of system evaluation. In March 1995, the AMU began sending real-time MASS output to the forecasters and meteorologists at CCAS, Spaceflight Meteorology Group (Johnson Space Center, Houston, Texas), and the National Weather Service (Melbourne, Florida). However, MASS is not yet an operational system. The final decision whether to transition MASS for operational use will depend on a combination of forecaster feedback, the AMU's final evaluation results, and the life-cycle costs of the operational system.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/24077621','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/24077621"><span id="translatedtitle">Efficient analysis of Q-level <span class="hlt">nested</span> hierarchical general linear <span class="hlt">models</span> given ignorable missing data.</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Shin, Yongyun; Raudenbush, Stephen W</p> <p>2013-01-01</p> <p>This article extends single-level missing data methods to efficient estimation of a Q-level <span class="hlt">nested</span> hierarchical general linear <span class="hlt">model</span> given ignorable missing data with a general missing pattern at any of the Q levels. The key idea is to reexpress a desired hierarchical <span class="hlt">model</span> as the joint distribution of all variables including the outcome that are subject to missingness, conditional on all of the covariates that are completely observed and to estimate the joint <span class="hlt">model</span> under normal theory. The unconstrained joint <span class="hlt">model</span>, however, identifies extraneous parameters that are not of interest in subsequent analysis of the hierarchical <span class="hlt">model</span> and that rapidly multiply as the number of levels, the number of variables subject to missingness, and the number of random coefficients grow. Therefore, the joint <span class="hlt">model</span> may be extremely high dimensional and difficult to estimate well unless constraints are imposed to avoid the proliferation of extraneous covariance components at each level. Furthermore, the over-identified hierarchical <span class="hlt">model</span> may produce considerably biased inferences. The challenge is to represent the constraints within the framework of the Q-level <span class="hlt">model</span> in a way that is uniform without regard to Q; in a way that facilitates efficient computation for any number of Q levels; and also in a way that produces unbiased and efficient analysis of the hierarchical <span class="hlt">model</span>. Our approach yields Q-step recursive estimation and imputation procedures whose qth-step computation involves only level-q data given higher-level computation components. We illustrate the approach with a study of the growth in body mass index analyzing a national sample of elementary school children. PMID:24077621</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2011BoLMe.139..121R&link_type=ABSTRACT','NASAADS'); return false;" href="http://adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2011BoLMe.139..121R&link_type=ABSTRACT"><span id="translatedtitle">The Simulation of the Opposing Fluxes of Latent Heat and CO2 over Various Land-Use Types: Coupling a Gas Exchange <span class="hlt">Model</span> to a <span class="hlt">Mesoscale</span> Atmospheric <span class="hlt">Model</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Reyers, Mark; Krüger, Andreas; Werner, Christiane; Pinto, Joaquim G.; Zacharias, Stefan; Kerschgens, Michael</p> <p>2011-04-01</p> <p>A <span class="hlt">mesoscale</span> meteorological <span class="hlt">model</span> (FOOT3DK) is coupled with a gas exchange <span class="hlt">model</span> to simulate surface fluxes of CO2 and H2O under field conditions. The gas exchange <span class="hlt">model</span> consists of a C3 single leaf photosynthesis sub-<span class="hlt">model</span> and an extended big leaf (sun/shade) sub-<span class="hlt">model</span> that divides the canopy into sunlit and shaded fractions. Simulated CO2 fluxes of the stand-alone version of the gas exchange <span class="hlt">model</span> correspond well to eddy-covariance measurements at a test site in a rural area in the west of Germany. The coupled FOOT3DK/gas exchange <span class="hlt">model</span> is validated for the diurnal cycle at singular grid points, and delivers realistic fluxes with respect to their order of magnitude and to the general daily course. Compared to the Jarvis-based big leaf scheme, simulations of latent heat fluxes with a photosynthesis-based scheme for stomatal conductance are more realistic. As expected, flux averages are strongly influenced by the underlying land cover. While the simulated net ecosystem exchange is highly correlated with leaf area index, this correlation is much weaker for the latent heat flux. Photosynthetic CO2 uptake is associated with transpirational water loss via the stomata, and the resulting opposing surface fluxes of CO2 and H2O are reproduced with the <span class="hlt">model</span> approach. Over vegetated surfaces it is shown that the coupling of a photosynthesis-based gas exchange <span class="hlt">model</span> with the land-surface scheme of a <span class="hlt">mesoscale</span> <span class="hlt">model</span> results in more realistic simulated latent heat fluxes.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2010EGUGA..12.2653A','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2010EGUGA..12.2653A"><span id="translatedtitle">The impact of soil moisture inhomogeneities on modification of a <span class="hlt">mesoscale</span> convective system: a budget-based <span class="hlt">model</span> analysis</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Adler, Bianca; Gantner, Leonhard; Kalthoff, Norbert</p> <p>2010-05-01</p> <p>In order to investigate the sensitivity of a <span class="hlt">mesoscale</span> convective system (MCS) to soil moisture inhomogeneities in West Africa cloud-resolving simulations with the COSMO-<span class="hlt">Model</span> initialized with European Centre for Medium-range Weather Forecasts analyses data were performed. Three scenarios were investigated: homogeneous soil type and soil moisture (HOM) and homogeneous soil type with a north-south oriented band of two degrees width with reduced soil moisture (BANDT) and with increased soil moisture (BANDM). In all experiments an MCS developed east of the band in the late afternoon. Precipitation related to the MCS was continuously strong in HOM. When the MCS approached the band with reduced soil moisture in BANDT precipitation decreased because of higher convective inhibition (CIN) ahead of the band. Reaching the drier band precipitation increased again. The moist band in BANDM caused an increase of precipitation ahead of the band and a decrease in the area with higher soil moisture caused by very high CIN values. Soil moisture inhomogeneities induced thermal circulations which led to modified conditions in the lower troposphere and to changes in CIN and accounted for the modification of precipitation of an MCS. In BANDT, precipitating cells already developed in the western part of the dry band in the late afternoon, where convergence, generated by thermal circulations and supported by downward mixing of momentum from the African Easterly Jet, triggered convection.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/servlets/purl/10192259','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/servlets/purl/10192259"><span id="translatedtitle">Development of advanced cloud parameterizations to examine air quality, cloud properties, and cloud-radiation feedback in <span class="hlt">mesoscale</span> <span class="hlt">models</span></span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Lee, In Young</p> <p>1993-09-01</p> <p>The distribution of atmospheric pollutants is governed by dynamic processes that create the general conditions for transport and mixing, by microphysical processes that control the evolution of aerosol and cloud particles, and by chemical processes that transform chemical species and form aerosols. Pollutants emitted into the air can undergo homogeneous gas reactions to create a suitable environment for the production by heterogeneous nucleation of embryos composed of a few molecules. The physicochemical properties of preexisting aerosols interact with newly produced embryos to evolve by heteromolecular diffusion and coagulation. Hygroscopic particles wig serve as effective cloud condensation nuclei (CCN), while hydrophobic particles will serve as effective ice-forming nuclei. Clouds form initially by condensation of water vapor on CCN and evolve in a vapor-liquid-solid system by deposition, sublimation, freezing, melting, coagulation, and breakup. Gases and aerosols that enter the clouds undergo aqueous chemical processes and may acidity hydrometer particles. Calculations for solar and longwave radiation fluxes depend on how the respective spectra are modified by absorbers such as H{sub 2}O, CO{sub 2}, O{sub 3}, CH{sub 4}, N{sub 2}O, chlorofruorocarbons, and aerosols. However, the flux calculations are more complicated for cloudy skies, because the cloud optical properties are not well defined. In this paper, key processes such as tropospheric chemistry, cloud microphysics parameterizations, and radiation schemes are reviewed in terms of physicochemical processes occurring, and recommendations are made for the development of advanced modules applicable to <span class="hlt">mesoscale</span> <span class="hlt">models</span>.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014JGRC..119.4745C','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014JGRC..119.4745C"><span id="translatedtitle"><span class="hlt">Mesoscale</span> activity in the Comoros Basin from satellite altimetry and a high-resolution ocean circulation <span class="hlt">model</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Collins, C.; Hermes, J. C.; Reason, C. J. C.</p> <p>2014-08-01</p> <p>Recently it has been shown that anticyclonic eddies are generated in the Comoros Basin contesting the long-held notion of a single large anticyclonic cell, the Comoros Gyre. Limited knowledge exists about the <span class="hlt">mesoscale</span> activity within the basin, a potential key source of variability for the Mozambique Channel and subsequently the Agulhas Current. In this paper an automated eddy tracking scheme, applied to satellite altimetry data and a high-resolution <span class="hlt">model</span> simulation, is used to determine the characteristics of the anticyclonic eddies generated in the Comoros Basin. The generation and characteristics of cyclonic eddies are also investigated. The eddy tracking scheme revealed that anticyclonic eddies are primarily generated west of the tip of Madagascar due to barotropic instabilities whereas cyclonic eddies are mainly generated along the northwest coast of Madagascar as a result of baroclinic instabilities. Anticyclonic eddies, with a mean lifespan of about 3 months, reside in the basin for half their lifespan before propagating into the Mozambique Channel. On the other hand, the majority of cyclonic eddies, with a similar mean lifespan, dissipate within the basin. Initially, the anticyclones, with translation speeds of 6-8 km d-1 and mean radii of 80-100 km, follow the trajectory of the North East Madagascar Current and turn south upon reaching the African coast. The cyclonic eddies tend to be smaller (˜60 km) and have slower translation speeds (2.5-3.5 km d-1) than their anticyclonic counterparts.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2016APS..MARX19009T&link_type=ABSTRACT','NASAADS'); return false;" href="http://adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2016APS..MARX19009T&link_type=ABSTRACT"><span id="translatedtitle">Electronic and Magnetic Properties of Transition-Metal Oxide Nanocomposites: A Tight-Binding <span class="hlt">Modeling</span> at <span class="hlt">Mesoscale</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Tai, Yuan-Yen; Zhu, Jian-Xin</p> <p></p> <p>Transition metal oxides (TMOs) exhibit many emergent phenomena ranging from high-temperature superconductivity and giant magnetoresistance to magnetism and ferroelectricity. In addition, when TMOs are interfaced with each other, new functionalities can arise, which are absent in individual components. In this talk, I will present an overview on our recent efforts in theoretical understanding of the electronic and magnetic properties TMO nanocomposites. In particular, I will introduce our recently developed tight-binding <span class="hlt">modeling</span> of these properties arising from the interplay of competing interactions at the interfaces of planar and pillar nanocomposites. Our theoretical tool package will provide a unique capability to address the emergent phenomena in TMO nanocomposites and their <span class="hlt">mesoscale</span> response to such effects like strain and microstructures at the interfaces, and ultimately help establish design principles of new multifunctionality with TMOs. This work was carried out under the auspices of the National Nuclear Security Administration of the U.S. Department of Energy at LANL under Contract No. DE-AC52-06NA25396, and was supported by the LANL LDRD Program.</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_20");'>20</a></li> <li><a href="#" onclick='return showDiv("page_21");'>21</a></li> <li class="active"><span>22</span></li> <li><a href="#" onclick='return showDiv("page_23");'>23</a></li> <li><a href="#" onclick='return showDiv("page_24");'>24</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_22 --> <div id="page_23" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_21");'>21</a></li> <li><a href="#" onclick='return showDiv("page_22");'>22</a></li> <li class="active"><span>23</span></li> <li><a href="#" onclick='return showDiv("page_24");'>24</a></li> <li><a href="#" onclick='return showDiv("page_25");'>25</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="441"> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014HESSD..11..451F','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014HESSD..11..451F"><span id="translatedtitle">Continental hydrosystem <span class="hlt">modelling</span>: the concept of <span class="hlt">nested</span> stream-aquifer interfaces</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Flipo, N.; Mouhri, A.; Labarthe, B.; Biancamaria, S.</p> <p>2014-01-01</p> <p>Recent developments in hydrological <span class="hlt">modelling</span> are based on a view of the interface being a single continuum through which water flows. These coupled hydrological-hydrogeological <span class="hlt">models</span>, emphasising the importance of the stream-aquifer interface, are more and more used in hydrological sciences for pluri-disciplinary studies aiming at investigating environmental issues. This notion of a single continuum, which is accepted by the hydrological <span class="hlt">modellers</span>, originates in the historical <span class="hlt">modelling</span> of hydrosystems based on the hypothesis of a homogeneous media that led to the Darcy law. There is then a need to first bridge the gap between hydrological and eco-hydrological views of the stream-aquifer interfaces, and, secondly, to rationalise the <span class="hlt">modelling</span> of stream-aquifer interface within a consistent framework that fully takes into account the multi-dimensionality of the stream-aquifer interfaces. We first define the concept of <span class="hlt">nested</span> stream-aquifer interfaces as a key transitional component of continental hydrosystem. Based on a literature review, we then demonstrate the usefulness of the concept for the multi-dimensional study of the stream-aquifer interface, with a special emphasis on the stream network, which is identified as the key component for scaling hydrological processes occurring at the interface. Finally we focus on the stream-aquifer interface <span class="hlt">modelling</span> at different scales, with up-to-date methodologies and give some guidances for the multi-dimensional <span class="hlt">modelling</span> of the interface using the innovative methodology MIM (Measurements-Interpolation-<span class="hlt">Modelling</span>), which is graphically developed, scaling in space the three pools of methods needed to fully understand stream-aquifer interfaces at various scales. The outcome of MIM is the localisation in space of the stream-aquifer interface types that can be studied by a given approach. The efficiency of the method is demonstrated with two approaches from the local (~1 m) to the continental (<10 M km2) scale.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2013AGUFM.H41G1313G','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2013AGUFM.H41G1313G"><span id="translatedtitle">Realism test of a topography driven conceptual <span class="hlt">model</span> (FLEX-Topo) in <span class="hlt">nested</span> catchments of the Heihe River Basins, China</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Gao, H.; Savenije, H.; Hrachowitz, M.; Fenicia, F.; Gharari, S.</p> <p>2013-12-01</p> <p>Although elevation data are globally available and many <span class="hlt">models</span> do take topographical information into account, here it is demonstrated that topography is still an under-exploiting source of information in hydrological <span class="hlt">models</span> . Based on the recently proposed <span class="hlt">modelling</span> approach (FLEX-Topo) a semi-distributed topographic driven conceptual <span class="hlt">model</span> (FLEXT), has been developed and tested in two <span class="hlt">nested</span> catchments of the Heihe river basin. The <span class="hlt">model</span> uses four topographical properties (i.e. Height Above the Nearest Drainage (HAND), absolute elevation, slope and aspect) to make a hydrological landscape classification which correspond with the dominant rainfall-runoff processes of these landscapes, to which a conceptual <span class="hlt">model</span> structure is attributed. To analyses the additional information provided by the landscape classification, the performance of the FLEXT <span class="hlt">model</span> is compared to a completely lumped hydrological <span class="hlt">models</span> (FLEXL) and a semi-distributed <span class="hlt">model</span> (FLEXD). All <span class="hlt">models</span> have been calibrated and validated at the catchment outlet. Additionally, the <span class="hlt">models</span> were evaluated in two <span class="hlt">nested</span> sub-catchments. FLEXT performs substantially better than the other two <span class="hlt">models</span> especially in the two <span class="hlt">nested</span> sub-catchments during validation. It is especially better equipped to represent rainfall-runoff events during the dry season, which supports the following hypotheses: (1) topography can be used to distinguish different landscape elements with different hydrological function; (2) the <span class="hlt">model</span> structure of the FLEXT is much better equipped to represent hydrological signatures than a lumped or semi-distributed <span class="hlt">model</span>, and hence has a more realistic <span class="hlt">model</span> structure and parameterization. The hydrograph components of the calibration(a), split-sample validation(b) and <span class="hlt">nested</span> sub-catchments validation(c,d), of the FLEXT <span class="hlt">model</span></p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015APS..DFDG30008P','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015APS..DFDG30008P"><span id="translatedtitle"><span class="hlt">Mesoscale</span> Ocean Large Eddy Simulations</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Pearson, Brodie; Fox-Kemper, Baylor; Bachman, Scott; Bryan, Frank</p> <p>2015-11-01</p> <p>The highest resolution global climate <span class="hlt">models</span> (GCMs) can now resolve the largest scales of <span class="hlt">mesoscale</span> dynamics in the ocean. This has the potential to increase the fidelity of GCMs. However, the effects of the smallest, unresolved, scales of <span class="hlt">mesoscale</span> dynamics must still be parametrized. One such family of parametrizations are <span class="hlt">mesoscale</span> ocean large eddy simulations (MOLES), but the effects of including MOLES in a GCM are not well understood. In this presentation, several MOLES schemes are implemented in a <span class="hlt">mesoscale</span>-resolving GCM (CESM), and the resulting flow is compared with that produced by more traditional sub-grid parametrizations. Large eddy simulation (LES) is used to simulate flows where the largest scales of turbulent motion are resolved, but the smallest scales are not resolved. LES has traditionally been used to study 3D turbulence, but recently it has also been applied to idealized 2D and quasi-geostrophic (QG) turbulence. The MOLES presented here are based on 2D and QG LES schemes.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/biblio/6227005','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/biblio/6227005"><span id="translatedtitle">An evaluation of sea level cyclone forecasts produced by NMC's <span class="hlt">Nested</span>-Grid <span class="hlt">Model</span> and Global Spectral <span class="hlt">Model</span></span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Smith, B.B.; Mullen, S.L. Arizona Univ., Tucson )</p> <p>1993-03-01</p> <p>An analysis of the 24- and 48-h sea level cyclone errors occurring in the NMC's <span class="hlt">Nested</span>-Grid <span class="hlt">Model</span> (NGM) and the Aviation Run of the Global Spectral <span class="hlt">Model</span> (AVN) during the 1987/1988 and 1989/1990 winter seasons is presented. Central pressure, 1000-500-mb thickness, and displacement errors for cyclone center are compared, and the circumstances under which one <span class="hlt">model</span> performs better than the other are documented. Overall, the NGM slightly overdeepens cyclones and the T80 AVN underdeepens cyclones when both <span class="hlt">models</span> are verified against the NGM initial panel. Both <span class="hlt">models</span> underdevelop oceanic and deep cyclones. The pressure error variance tends to be smaller for the AVN, particularly at 48 h. It is inferred that the variability of individual central pressure forecasts is smaller for the AVN. Mean absolute displacement errors are smaller for the T80 AVN than the NGM. 35 refs.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015AGUFMGC41B1098Y','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015AGUFMGC41B1098Y"><span id="translatedtitle"><span class="hlt">Mesoscale</span> <span class="hlt">Modeling</span> of Smoke Particles Distribution and Their Radiative Feedback over Northern Sub-Saharan African Region</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Yue, Y.; Wang, J.; Ichoku, C. M.; Ellison, L.</p> <p>2015-12-01</p> <p>Stretching from southern boundary of Sahara to the equator and expanding west to east from Atlantic Ocean coasts to the India Ocean coasts, the northern sub-Saharan African (NSSA) region has been subject to intense biomass burning. Comprised of savanna, shrub, tropical forest and a number of agricultural crops, the extensive fires burn belt covers central and south of NSSA during dry season (from October to March) contributes to one of the highest biomass burning rate per km2 in the world. Due to smoke particles' absorption effects of solar radiation, they can modify the surface and atmosphere temperature and thus change atmospheric stability, height of the boundary layer, regional atmospheric circulation, evaporation rate, cloud formation, and precipitation. Hence, smoke particles emitted from biomass burning over NSSA region has a significant influence to the air quality, weather and climate variability. In this study, the first version of this Fire Energetics and Emissions Research (FEER.v1) emissions of several smoke constituents including light-absorbing organic carbon (OC) and black carbon (BC) are applied to a state-of-science meteorology-chemistry <span class="hlt">model</span> as NOAA Weather Research and Forecasting <span class="hlt">Model</span> with Chemistry (WRF-Chem). We analyzed WRF-Chem simulations of surface and vertical distribution of various pollutants and their direct radiative effects in conjunction with satellite observation data from Moderate Resolution Imaging Spectroradiometer (MODIS) and Cloud-Aerosol Lidar data with Orthogonal Polarization (CALIPSO) to strengthen the importance of combining space measured emission products like FEER.v1 emission inventory with <span class="hlt">mesoscale</span> <span class="hlt">model</span> over intense biomass burning region, especially in area where ground-based air-quality and radiation-related observations are limited or absent.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014JPhCS.524a2116H','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014JPhCS.524a2116H"><span id="translatedtitle">Improvement of AEP Predictions Using Diurnal CFD <span class="hlt">Modelling</span> with Site-Specific Stability Weightings Provided from <span class="hlt">Mesoscale</span> Simulation</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Hristov, Y.; Oxley, G.; Žagar, M.</p> <p>2014-06-01</p> <p>The Bolund measurement campaign, performed by Danish Technical University (DTU) Wind Energy Department (also known as RISØ), provided significant insight into wind flow <span class="hlt">modeling</span> over complex terrain. In the blind comparison study several <span class="hlt">modelling</span> solutions were submitted with the vast majority being steady-state Computational Fluid Dynamics (CFD) approaches with two equation k-epsilon turbulence closure. This approach yielded the most accurate results, and was identified as the state-of-the-art tool for wind turbine generator (WTG) micro-siting. Based on the findings from Bolund, further comparison between CFD and field measurement data has been deemed essential in order to improve simulation accuracy for turbine load and long-term Annual Energy Production (AEP) estimations. Vestas Wind Systems A/S is a major WTG original equipment manufacturer (OEM) with an installed base of over 60GW in over 70 countries accounting for 19% of the global installed base. The Vestas Performance and Diagnostic Centre (VPDC) provides online live data to more than 47GW of these turbines allowing a comprehensive comparison between <span class="hlt">modelled</span> and real-world energy production data. In previous studies, multiple sites have been simulated with a steady neutral CFD formulation for the atmospheric surface layer (ASL), and wind resource (RSF) files have been generated as a base for long-term AEP predictions showing significant improvement over predictions performed with the industry standard linear WAsP tool. In this study, further improvements to the wind resource file generation with CFD are examined using an unsteady diurnal cycle approach with a full atmospheric boundary layer (ABL) formulation, with the unique stratifications throughout the cycle weighted according to <span class="hlt">mesoscale</span> simulated sectorwise stability frequencies.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016EGUGA..1817875F','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016EGUGA..1817875F"><span id="translatedtitle">Domain <span class="hlt">nesting</span> for multi-scale large eddy simulation</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Fuka, Vladimir; Xie, Zheng-Tong</p> <p>2016-04-01</p> <p>The need to simulate city scale areas (O(10 km)) with high resolution within street canyons in certain areas of interests necessitates different grid resolutions in different part of the simulated area. General purpose computational fluid dynamics codes typically employ unstructured refined grids while <span class="hlt">mesoscale</span> meteorological <span class="hlt">models</span> more often employ <span class="hlt">nesting</span> of computational domains. ELMM is a large eddy simulation <span class="hlt">model</span> for the atmospheric boundary layer. It employs orthogonal uniform grids and for this reason domain <span class="hlt">nesting</span> was chosen as the approach for simulations in multiple scales. Domains are implemented as sets of MPI processes which communicate with each other as in a normal non-<span class="hlt">nested</span> run, but also with processes from another (outer/inner) domain. It should stressed that the duration of solution of time-steps in the outer and in the inner domain must be synchronized, so that the processes do not have to wait for the completion of their boundary conditions. This can achieved by assigning an appropriate number of CPUs to each domain, and to gain high efficiency. When <span class="hlt">nesting</span> is applied for large eddy simulation, the inner domain receives inflow boundary conditions which lack turbulent motions not represented by the outer grid. ELMM remedies this by optional adding of turbulent fluctuations to the inflow using the efficient method of Xie and Castro (2008). The spatial scale of these fluctuations is in the subgrid-scale of the outer grid and their intensity will be estimated from the subgrid turbulent kinetic energy in the outer grid.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016EGUGA..18.7767Y','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016EGUGA..18.7767Y"><span id="translatedtitle">Hydrological <span class="hlt">model</span> parameters identification in a coastal <span class="hlt">nested</span> catchment in Mersin province (SE Turkey)</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Yıldırım, Ümit; Jomaa, Seifeddine; Güler, Cüneyt; Rode, Michael</p> <p>2016-04-01</p> <p>It is known that the coastal Mediterranean region is facing a serious problem of water resources exploitation due to the rapid demographic, socio-economic, land use and climate changes. The hydrological <span class="hlt">modeling</span> has proven to be an efficient tool for better water resources prediction and management. In this study, the HYdrological Predictions for the Environment (HYPE) <span class="hlt">model</span> was setup on the <span class="hlt">nested</span> coastal Sorgun catchment in Turkey (449 km2). This catchment is located in the east part of the Mersin province and is characterized by extremely varied topography, land use, and population density in semi-arid Mediterranean climate conditions. First, the <span class="hlt">model</span> was calibrated at the catchment outlet (Sarilar) for the period 2003-2006. Second, the <span class="hlt">model</span> was validated temporally for the period 2009-2013 at daily and monthly time intervals. In addition, the <span class="hlt">model</span> performance was tested spatially using an internal station (B. Sorgun, 269 km2) located in the headwater region. Results showed that the HYPE <span class="hlt">model</span> could reproduce the measured daily discharge significantly well (Nash Sutcliffe Efficiency (NSE) were 0.78 and 0.68 for calibration and validation periods, respectively). For monthly time step, the <span class="hlt">model</span> performs better compared with daily time interval (NSE were 0.92 and 0.83 for calibration and validation periods, respectively). The <span class="hlt">model</span> could represent the water balance relatively good at daily and monthly time steps, where the lowest PBIAS (percentage bias) were - 4.19% and - 3.53% for daily and monthly time intervals, respectively (considering the whole period). Results revealed, however, the agreement between the predicted and measured discharge was reduced, when the same best optimized <span class="hlt">model</span>-parameters at Sarilar gauging station (catchment outlet) were used at B. Sorgun station (internal station). This <span class="hlt">model</span> transferability less performance at internal station can be explained by the clear changes in terms of land use, soil type and precipitation rate in the</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2012JGRD..11713114S&link_type=ABSTRACT','NASAADS'); return false;" href="http://adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2012JGRD..11713114S&link_type=ABSTRACT"><span id="translatedtitle">Genesis of twin tropical cyclones as revealed by a global <span class="hlt">mesoscale</span> <span class="hlt">model</span>: The role of mixed Rossby gravity waves</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Shen, Bo-Wen; Tao, Wei-Kuo; Lin, Yuh-Lang; Laing, Arlene</p> <p>2012-07-01</p> <p>In this study, it is proposed that twin tropical cyclones (TCs), Kesiny and 01A, in May 2002 formed in association with the scale interactions of three gyres that appeared as a convectively coupled mixed Rossby gravity (ccMRG) wave during an active phase of the Madden-Julian Oscillation (MJO). This is shown by analyzing observational data, including NCEP reanalysis data and METEOSAT 7 IR satellite imagery, and performing numerical simulations using a global <span class="hlt">mesoscale</span> <span class="hlt">model</span>. A 10-day control run is initialized at 0000 UTC 1 May 2002 with grid-scale condensation but no sub-grid cumulus parameterizations. The ccMRG wave was identified as encompassing two developing and one non-developing gyres, the first two of which intensified and evolved into the twin TCs. The control run is able to reproduce the evolution of the ccMRG wave and thus the formation of the twin TCs about two and five days in advance as well as their subsequent intensity evolution and movement within an 8-10 day period. Five additional 10-day sensitivity experiments with different <span class="hlt">model</span> configurations are conducted to help understand the interaction of the three gyres, leading to the formation of the TCs. These experiments suggest the improved lead time in the control run may be attributed to the realistic simulation of the ccMRG wave with the following processes: (1) wave deepening (intensification) associated with a reduction in wavelength and/or the intensification of individual gyres, (2) poleward movement of gyres that may be associated with boundary layer processes, (3) realistic simulation of moist processes at regional scales in association with each of the gyres, and (4) the vertical phasing of low- and mid-level cyclonic circulations associated with a specific gyre.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/20140010321','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20140010321"><span id="translatedtitle">Genesis of Twin Tropical Cyclones as Revealed by a Global <span class="hlt">Mesoscale</span> <span class="hlt">Model</span>: The Role of Mixed Rossby Gravity Waves</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Shen, Bo-Wen; Tao, Wei-Kuo; Lin, Yuh-Lang; Laing, Arlene</p> <p>2012-01-01</p> <p>In this study, it is proposed that twin tropical cyclones (TCs), Kesiny and 01A, in May 2002 formed in association with the scale interactions of three gyres that appeared as a convectively coupled mixed Rossby gravity (ccMRG) wave during an active phase of the Madden-Julian Oscillation (MJO). This is shown by analyzing observational data, including NCEP reanalysis data and METEOSAT 7 IR satellite imagery, and performing numerical simulations using a global <span class="hlt">mesoscale</span> <span class="hlt">model</span>. A 10-day control run is initialized at 0000 UTC 1 May 2002 with grid-scale condensation but no sub-grid cumulus parameterizations. The ccMRG wave was identified as encompassing two developing and one non-developing gyres, the first two of which intensified and evolved into the twin TCs. The control run is able to reproduce the evolution of the ccMRG wave and thus the formation of the twin TCs about two and five days in advance as well as their subsequent intensity evolution and movement within an 8-10 day period. Five additional 10-day sensitivity experiments with different <span class="hlt">model</span> configurations are conducted to help understand the interaction of the three gyres, leading to the formation of the TCs. These experiments suggest the improved lead time in the control run may be attributed to the realistic simulation of the ccMRG wave with the following processes: (1) wave deepening (intensification) associated with a reduction in wavelength and/or the intensification of individual gyres, (2) poleward movement of gyres that may be associated with boundary layer processes, (3) realistic simulation of moist processes at regional scales in association with each of the gyres, and (4) the vertical phasing of low- and mid-level cyclonic circulations associated with a specific gyre.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://ntrs.nasa.gov/search.jsp?R=20120013630&hterms=Cyclones&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D30%26Ntt%3DCyclones','NASA-TRS'); return false;" href="http://ntrs.nasa.gov/search.jsp?R=20120013630&hterms=Cyclones&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D30%26Ntt%3DCyclones"><span id="translatedtitle">Genesis of Twin Tropical Cyclones as Revealed by a Global <span class="hlt">Mesoscale</span> <span class="hlt">Model</span>: The Role of Mixed Rossby Gravity Waves</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Shen, Bo-Wen; Tao, Wei-Kuo; Lin, Yuh-Lang; Laing, Arlene</p> <p>2012-01-01</p> <p>In this study, it is proposed that twin tropical cyclones (TCs), Kesiny and 01A, in May 2002 formed in association with the scale interactions of three gyres that appeared as a convectively-coupled mixed Rossby gravity (ccMRG) wave during an active phase of the Madden-Julian Oscillation (MJO). This is shown by analyzing observational data and performing simulations using a global <span class="hlt">mesoscale</span> <span class="hlt">model</span>. A 10-day control run is initialized at 0000 UTC 1 May 2002 with grid-scale condensation but no cumulus parameterizations. The ccMRG wave was identified as encompassing two developing and one non-developing gyres, the first two of which intensified and evolved into the twin TCs. The control run is able to reproduce the evolution of the ccMRG wave and the formation of the twin TCs about two and five days in advance as well as their subsequent intensity evolution and movement within an 8-10 day period. Five additional 10-day sensitivity experiments with different <span class="hlt">model</span> configurations are conducted to help understand the interaction of the three gyres. These experiments suggest the improved lead time in the control run may be attributed to the realistic simulation of the ccMRG wave with the following processes: (I) wave deepening associated with wave shortening and/or the intensification of individual gyres, (2) poleward movement of gyres that may be associated with bOlll1dary layer processes, (3) realistic simulation of moist processes at regional scales in association with each of the gyres, and (4) the vertical phasing of low- and mid-level cyclonic circulations associated with a specific gyre.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2003HESS....7..812K','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2003HESS....7..812K"><span id="translatedtitle">Precipitation forecasting by a <span class="hlt"