Science.gov

Sample records for nested mesoscale model

  1. 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.

  2. 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.

  3. 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.

  4. 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.

  5. Examples of data assimilation in mesoscale models

    NASA Technical Reports Server (NTRS)

    Carr, Fred; Zack, John; Schmidt, Jerry; Snook, John; Benjamin, Stan; Stauffer, David

    1993-01-01

    The keynote address was the problem of physical initialization of mesoscale models. The classic purpose of physical or diabatic initialization is to reduce or eliminate the spin-up error caused by the lack, at the initial time, of the fully developed vertical circulations required to support regions of large rainfall rates. However, even if a model has no spin-up problem, imposition of observed moisture and heating rate information during assimilation can improve quantitative precipitation forecasts, especially early in the forecast. The two key issues in physical initialization are the choice of assimilating technique and sources of hydrologic/hydrometeor data. Another example of data assimilation in mesoscale models was presented in a series of meso-beta scale model experiments with and 11 km version of the MASS model designed to investigate the sensitivity of convective initiation forced by thermally direct circulations resulting from differential surface heating to four dimensional assimilation of surface and radar data. The results of these simulations underscore the need to accurately initialize and simulate grid and sub-grid scale clouds in meso- beta scale models. The status of the application of the CSU-RAMS mesoscale model by the NOAA Forecast Systems Lab for producing real-time forecasts with 10-60 km mesh resolutions over (4000 km)(exp 2) domains for use by the aviation community was reported. Either MAPS or LAPS model data are used to initialize the RAMS model on a 12-h cycle. The use of MAPS (Mesoscale Analysis and Prediction System) model was discussed. Also discussed was the mesobeta-scale data assimilation using a triply-nested nonhydrostatic version of the MM5 model.

  6. 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.

  7. Dynamic Model of Mesoscale Eddies

    NASA Astrophysics Data System (ADS)

    Dubovikov, Mikhail S.

    2003-04-01

    Oceanic mesoscale eddies which are analogs of well known synoptic eddies (cyclones and anticyclones), are studied on the basis of the turbulence model originated by Dubovikov (Dubovikov, M.S., "Dynamical model of turbulent eddies", Int. J. Mod. Phys.B7, 4631-4645 (1993).) and further developed by Canuto and Dubovikov (Canuto, V.M. and Dubovikov, M.S., "A dynamical model for turbulence: I. General formalism", Phys. Fluids8, 571-586 (1996a) (CD96a); Canuto, V.M. and Dubovikov, M.S., "A dynamical model for turbulence: II. Sheardriven flows", Phys. Fluids8, 587-598 (1996b) (CD96b); Canuto, V.M., Dubovikov, M.S., Cheng, Y. and Dienstfrey, A., "A dynamical model for turbulence: III. Numerical results", Phys. Fluids8, 599-613 (1996c)(CD96c); Canuto, V.M., Dubovikov, M.S. and Dienstfrey, A., "A dynamical model for turbulence: IV. Buoyancy-driven flows", Phys. Fluids9, 2118-2131 (1997a) (CD97a); Canuto, V.M. and Dubovikov, M.S., "A dynamical model for turbulence: V. The effect of rotation", Phys. Fluids9, 2132-2140 (1997b) (CD97b); Canuto, V.M., Dubovikov, M.S. and Wielaard, D.J., "A dynamical model for turbulence: VI. Two dimensional turbulence", Phys. Fluids9, 2141-2147 (1997c) (CD97c); Canuto, V.M. and Dubovikov, M.S., "Physical regimes and dimensional structure of rotating turbulence", Phys. Rev. Lett. 78, 666-669 (1997d) (CD97d); Canuto, V.M., Dubovikov, M.S. and Dienstfrey, A., "Turbulent convection in a spectral model", Phys. Rev. Lett. 78, 662-665 (1997e) (CD97e); Canuto, V.M. and Dubovikov, M.S., "A new approach to turbulence", Int. J. Mod. Phys.12, 3121-3152 (1997f) (CD97f); Canuto, V.M. and Dubovikov, M.S., "Two scaling regimes for rotating Raleigh-Benard convection", Phys. Rev. Letters78, 281-284, (1998) (CD98); Canuto, V.M. and Dubovikov, M.S., "A dynamical model for turbulence: VII. The five invariants for shear driven flows", Phys. Fluids11, 659-664 (1999a) (CD99a); Canuto, V.M., Dubovikov, M.S. and Yu, G., "A dynamical model for turbulence: VIII. IR and UV

  8. Nano- and mesoscale modeling of cement matrix

    NASA Astrophysics Data System (ADS)

    Yu, Zechuan; Lau, Denvid

    2015-04-01

    Atomistic simulations of cementitious material can enrich our understanding of its structural and mechanical properties, whereas current computational capacities restrict the investigation length scale within 10 nm. In this context, coarse-grained simulations can translate the information from nanoscale to mesoscale, thus bridging the multi-scale investigations. Here, we develop a coarse-grained model of cement matrix using the concept of disk-like building block. The objective is to introduce a new method to construct a coarse-grained model of cement, which could contribute to the scale-bridging issue from nanoscale to mesoscale. PAC codes: 07.05.Tp, 62.25.-g, 82.70.Dd

  9. Nano- and mesoscale modeling of cement matrix.

    PubMed

    Yu, Zechuan; Lau, Denvid

    2015-01-01

    Atomistic simulations of cementitious material can enrich our understanding of its structural and mechanical properties, whereas current computational capacities restrict the investigation length scale within 10 nm. In this context, coarse-grained simulations can translate the information from nanoscale to mesoscale, thus bridging the multi-scale investigations. Here, we develop a coarse-grained model of cement matrix using the concept of disk-like building block. The objective is to introduce a new method to construct a coarse-grained model of cement, which could contribute to the scale-bridging issue from nanoscale to mesoscale. PAC codes: 07.05.Tp, 62.25.-g, 82.70.Dd.

  10. 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.

  11. Effective roughness in meso-scale modeling.

    NASA Astrophysics Data System (ADS)

    Nielsen, Joakim R.

    2010-05-01

    Effective roughness in meso-scale modeling. J.R. Nielsen, E. Dellwik, A. Hahmann, A. Sogachev, C.B. Hasager, Wind Energy Division, Risø DTU National Laboratory, Denmark Accurate estimation of effective roughness lengths for use in meso-scale models in heterogeneous terrain requires assessment of highly non-linear processes. These non-linear effects are often neglected in meso-scale modeling where, typically, a simple logarithmic average or a dominant vegetation type provide crude estimates of the aggregated aerodynamical roughness length in each grid cell. Although the parameterizations are computationally efficient, improvements are needed since some regional-scale sensitivity studies indicate that grid cell roughnesses strongly influence model predictions (i.e. Hasager and Jensen, 1999). Effective roughness parameterizations can be provided through the use of microscale flow models, which simulate the he local scale effect of orography and roughness changes. Results from two linearized micro-scale models and a k-ω model (Sogachev and Panferov, 2006) are presented for an idealized terrain with roughness changes. Furthermore, sensitivity experiments are performed within the meso-scale model WRF (Weather Research and Forecasting) using the standard Community Noah Land Surface model. The same experiment will be performed with a new modified version with multi-physics options (Niu et al.,submitted 2009). The analysis is carried out using different roughness aggregation techniques in WRF and the influence on scalar fluxes such as temperature, humidity and CO2 is investigated. Based on the WRF sensitivity analysis and the results of micro-scale modeling, the potential improvement of using micro-scale models for parameterization of sub-grid scale variability is evaluated.

  12. 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.

  13. 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.

  14. 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.

  15. Validation of a 3-D hemispheric nested air pollution model

    NASA Astrophysics Data System (ADS)

    Frohn, L. M.; Christensen, J. H.; Brandt, J.; Geels, C.; Hansen, K. M.

    2003-07-01

    Several air pollution transport models have been developed at the National Environmental Research Institute in Denmark over the last decade (DREAM, DEHM, ACDEP and DEOM). A new 3-D nested Eulerian transport-chemistry model: REGIonal high resolutioN Air pollution model (REGINA) is based on modules and parameterisations from these models as well as new methods. The model covers the majority of the Northern Hemisphere with currently one nest implemented. The horizontal resolution in the mother domain is 150 km × 150 km, and the nesting factor is three. A chemical scheme (originally 51 species) has been extended with a detailed description of the ammonia chemistry and implemented in the model. The mesoscale numerical weather prediction model MM5v2 is used as meteorological driver for the model. The concentrations of air pollutants, such as sulphur and nitrogen in various forms, have been calculated, applying zero nesting and one nest. The model setup is currently being validated by comparing calculated values of concentrations to measurements from approximately 100 stations included in the European Monitoring and Evalutation Programme (EMEP). The present paper describes the physical processes and parameterisations of the model together with the modifications of the chemical scheme. Validation of the model calculations by comparison to EMEP measurements for a summer and a winter month is shown and discussed. Furthermore, results from a sensitivity study of the model performance with respect to resolution in emission and meteorology input data is presented. Finally the future prospects of the model are discussed. The overall validation shows that the model performs well with respect to correlation for both monthly and daily mean values.

  16. 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

  17. 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.

  18. 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.

  19. 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.

  20. 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.

  1. 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.

  2. 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.

  3. Analysis of atmospheric mesoscale models for entry, descent, and landing

    NASA Astrophysics Data System (ADS)

    Kass, D. M.; Schofield, J. T.; Michaels, T. I.; Rafkin, S. C. R.; Richardson, M. I.; Toigo, A. D.

    2003-11-01

    Each Mars Exploration Rover (MER) is sensitive to the Martian winds encountered near the surface during the entry, descent, and landing (EDL) process. These winds are strongly influenced by local (mesoscale) conditions. In the absence of suitable wind observations, wind fields predicted by Martian mesoscale atmospheric models have been analyzed to guide landing site selection. In order to encompass the available models and render them useful to the EDL engineering team, a series of statistical techniques was applied to the model results. These analyses cover the high-priority landing sites during the expected landing times (1200-1500 LT). The number of sites studied is limited by the computational and analysis cost of the mesoscale models. The statistical measures concentrate on the effective mean wind (the wind as seen by the landing system) and on the vertical structure of the horizontal winds. Both aspects are potentially hazardous to the MER landing system. In addition, a number of individual wind profiles from the mesoscale model were processed into a form that can be used directly by the EDL Monte Carlo simulations. The statistical analysis indicates that the Meridiani Planum and Elysium landing sites are probably safe. The Gusev Crater and Isidis Basin sites may be safe, but further analysis by the EDL engineers will be necessary to quantify the actual risk. Finally, the winds at the Melas Chasma landing site (and presumably other Valles Marineris landing sites) are dangerous. While the statistical parameters selected for these studies were primarily of engineering and safety interest, the techniques are potentially useful for more general scientific analyses. One interesting result of the current analysis is that the depth of the convective boundary layer (and thus the resulting energy density) appears to be primarily driven by the existence of a well-organized mesoscale (or regional) circulation, primarily driven by large-scale topographic features at Mars.

  4. 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

  5. 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.

  6. 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.

  7. Offshore Wind Resource Assessment Based on Mesoscale Modeling

    NASA Astrophysics Data System (ADS)

    Dvorak, M. J.; Jacobson, M. Z.

    2008-12-01

    A methodology for assessing regional offshore wind energy development potential using mesoscale modeling for wind fields has been developed. Recommendations are made on selecting the best mesoscale modeling domain resolution, as well as choosing the best data for model initial and boundary conditions, based on a sensitivity study using the Penn State/NCAR MM5 mesoscale model near California coast validated with offshore buoy wind data and coastal meteorological stations. Annual wind speed averages are developed by modeling four seasonal months to reduce total computational time, as well as to allow study of the innterannual variability. Four seasonal months of 2005, 2006, and 2007 were compared to using a complete modeled year for 2007 to calculate how the overall energy answer changed. Results from summer 2006 MM5 simulations show the average 10 m wind speed to be calculated within one percent when using three months of data (Jun, Jul, Aug) versus using July alone. Siting restrictions were developed based on bathymetry depth limits for offshore turbine tower support structures with economic and structural limitations for monopiles, multi-leg, and future floating tower support types corresponding to 30, 70, and 200 m depth respectively. Other exclusionary entities such as shipping lanes and avarian flyways were also considered as exclusion zones inside of areas amenable for offshore wind energy farms. A method to validate the modeled wind fields though error calculations against offshore buoy wind data, as well as onshore coastal meteorological towers is presented.

  8. 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.

  9. 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.

  10. 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

  11. 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

  12. Mesoscale atmospheric modeling for emergency response

    SciTech Connect

    O'Steen, B.L.; Fast, J.D.

    1992-01-01

    Atmospheric transport models for emergency response have traditionally utilized meteorological fields interpolated from sparse data to predict contaminant transport. Often these fields are adjusted to satisfy constraints derived from the governing equations of geophysical fluid dynamics, e.g. mass continuity. Gaussian concentration distributions or stochastic models are then used to represent turbulent diffusion of a contaminant in the diagnosed meteorological fields. The popularity of these models derives from their relative simplicity, ability to make reasonable short-term predictions and, most important, execution speed. The ability to generate a transport prediction for an accidental release from the Savannah River Site in a time frame which will allow protective action to be taken is essential in an emergency response operation.

  13. Mesoscale atmospheric modeling for emergency response

    SciTech Connect

    O`Steen, B.L.; Fast, J.D.

    1992-12-31

    Atmospheric transport models for emergency response have traditionally utilized meteorological fields interpolated from sparse data to predict contaminant transport. Often these fields are adjusted to satisfy constraints derived from the governing equations of geophysical fluid dynamics, e.g. mass continuity. Gaussian concentration distributions or stochastic models are then used to represent turbulent diffusion of a contaminant in the diagnosed meteorological fields. The popularity of these models derives from their relative simplicity, ability to make reasonable short-term predictions and, most important, execution speed. The ability to generate a transport prediction for an accidental release from the Savannah River Site in a time frame which will allow protective action to be taken is essential in an emergency response operation.

  14. 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...

  15. 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.

  16. Mesoscale modeling of dislocations in molecular crystals

    NASA Astrophysics Data System (ADS)

    Lei, Lei; Koslowski, Marisol

    2011-02-01

    Understanding the inelastic deformation of molecular crystals is of fundamental importance to the modeling of the processing of drugs in the pharmaceutical industry as well as to the initiation of detonation in high energy density materials. In this work, we present dislocation dynamics simulations of the deformation of two molecular crystals of interest in the pharmaceutical industry, sucrose and paracetamol. The simulations calculate the yield stress of sucrose and paracetamol in good agreement with experimental observation and predict the anisotropy in the mechanical response observed in these materials. Our results show that dislocation dynamics is an effective tool to study plastic deformation in molecular crystals.

  17. 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.

  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. Animal models and integrated nested Laplace approximations.

    PubMed

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

    2013-08-07

    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.

  1. 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

  2. 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.

  3. Beaufort Sea Mesoscale Meteorology Modeling Study: Sea Breeze Simulation

    NASA Astrophysics Data System (ADS)

    Liu, F.; Zhang, J.

    2009-12-01

    The Beaufort Sea and its adjacent continental areas are prominent geographical features which are largely covered by sea ice on a seasonal basis over the ocean and bounded by the Brooks Range in the south on land. This complex geographical environment offers unique challenges for mesoscale meteorology modeling. Further oil development in this area requires improved understanding of the surface wind field, a crucial parameter for assessing and predicting dispersal and movement of oil spills. As thus a study has been established to investigate the mesoscale features of the surface wind field throughout this region, specifically in relation to the sea breeze and topographic effects. In this study, we focus on the sea breeze effect. Based on the analysis of observed surface winds at the weather stations along the Beaufort coast, as well as model simulations with the weather research and forecast model (WRF), we found that the sea breeze along the Beaufort Sea coast is of different from the temperate latitude. Due to the stable Arctic boundary layer (inversion), which is unfavorable for the vertical convection, the offshore flow aloft occurs at relatively low level. In addition, due to continuous solar radiation, the sea breeze along the Beaufort coast is not followed by the land breeze. However the sea breeze’s strength and horizontal extent demonstrate a diurnal variation. The wind direction shows clockwise turning from 12:00 AKST to 00:00 AKST. Sea breeze could be a dominant factor causing the wind variation along the Beaufort Sea coast.

  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. Nonlinear natural engine: Model for thermodynamic processes in mesoscale systems

    PubMed Central

    Wheatley, John; Buchanan, D. S.; Swift, G. W.; Migliori, A.; Hofler, T.

    1985-01-01

    To develop intuition on the possible application of concepts from thermodynamic heat engines to mesoscale systems, we have constructed and studied a model thermoacoustic heat engine. The model consists of a chain of coupled nonlinear acoustic vibrators in which the primary thermodynamic medium is argon gas, the secondary thermodynamic medium is constituted by solids bounding the gas, and frequencies are ca. 3 × 102 Hz. The nonlinear elements are the necks, made flexible by means of an oil-loaded DuPont Kapton film, of Helmholtz resonators. When the primary medium is driven uniformly by an acoustic driver at a frequency somewhat below the low-amplitude resonant frequency and at a high enough driving amplitude, stationary localized or solitary states appear irreversibly on the chain. These are characterized by a higher vibrational amplitude than that in surrounding vibrators, where the amplitude can decrease; by the appearance of deep subharmonics of the drive frequency, corresponding to driven low-frequency vibrations of the Kapton film-oil systems; and by the pumping of heat toward the localized states. Possible implications of these results for mesoscale systems consisting of chains of molecular vibrators are then discussed. Images PMID:16593625

  6. 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.

  7. 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.

  8. 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.

  9. Modeling of Low Pressure Compaction and Mesoscale Localization

    NASA Astrophysics Data System (ADS)

    Roessig, Keith M.; Gonthier, Keith A.; Klomfass, Arno

    2004-07-01

    The compaction, ignition and deflagration of granular HMX have been widely studied. The bulk pressure within strong compaction waves is typically well above the HMX yield strength resulting in almost complete material consolidation. As such, bulk pressure dependent burn models can reasonably predict ignition and combustion for strong waves. However, long duration, low amplitude bulk pressure waves are much more difficult to characterize as stress fluctuations become increasingly important for ignition. Continuum models have recently been used to better predict ignition based on thermalization of bulk dissipated energy at the grain scale, but they typically do not account for the influence of mesoscale structure on the low pressure loading response. This work experimentally examines the influence of initial grain size on both the bulk quasistatic and dynamic loading behavior of granular HMX.

  10. 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.

  11. 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.

  12. 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.

  13. 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.

  14. 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.

  15. Towards water vapor assimilation into mesoscale models for improved precipitation forecast

    NASA Astrophysics Data System (ADS)

    Demoz, B.; Whiteman, D.; Venable, D.; Joseph, E.

    2006-05-01

    Atmospheric water vapor plays a primary role in the life cycle of clouds, precipitation and is crucial in understanding many aspects of the water cycle. It is very important to short-range mesoscale and storm-scale weather prediction. Specifically, accurate characterization of water vapor at low levels is a necessary condition for quantitative precipitation forecast (QPF), the initiation of convection and various thermodynamic and microphysical processes in mesoscale severe weather systems. However, quantification of its variability (both temporal and spatial) and integration of high quality and high frequency water vapor profiles into mesoscale models have been challenging. We report on a conceptual proposal that attempts to 1) define approporiate lidar-based data and instrumentation required for mesoscale data assimilation and 2) a possible federated network of ground-based lidars that may be capable of acquiring such high resolution water vapor data sets and 3) a possible frame work of assimilation of the data into a mesoscale model.

  16. 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

  17. 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

  18. 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.

  19. 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

  20. 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

  1. 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

  2. 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

  3. 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.

  4. 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.

  5. Solar Radiation Estimated Through Mesoscale Atmospheric Modeling over Northeast Brazil

    NASA Astrophysics Data System (ADS)

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

    2009-03-01

    The use of renewable energy sources, like solar, wind and biomass is rapidly increasing in recent years, with solar radiation as a particularly abundant energy source over Northeast Brazil. A proper quantitative knowledge of the incoming solar radiation is of great importance for energy planning in Brazil, serving as basis for developing future projects of photovoltaic power plants and solar energy exploitation. This work presents a methodology for mapping the incoming solar radiation at ground level for Northeast Brazil, using a mesoscale atmospheric model (Regional Atmospheric Modeling System—RAMS), calibrated and validated using data from the network of automatic surface stations from the State Foundation for Meteorology and Water Resources from Ceará (Fundação Cearense de Meteorologia e Recursos Hídricos- FUNCEME). The results showed that the model exhibits systematic errors, overestimating surface radiation, but that, after the proper statistical corrections, using a relationship between the model-predicted cloud fraction, the ground-level observed solar radiation and the incoming solar radiation estimated at the top of the atmosphere, a correlation of 0.92 with a confidence interval of 13.5 W/m2 is found for monthly data. Using this methodology, we found an estimate for annual average incoming solar radiation over Ceará of 215 W/m2 (maximum in October: 260 W/m2).

  6. 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

  7. 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.

  8. 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.

  9. 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.

  10. 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.

  11. 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

  12. 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.

  13. 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...

  14. 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

  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. 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

  17. 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

  18. 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.

  19. 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.

  20. 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

  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. 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.

  3. 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

  4. 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…

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

    USGS Publications Warehouse

    Vidale, P.L.; Pielke, R.A.; 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.

  6. 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.

  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. 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

  9. Weather Research and Forecasting Model with Vertical Nesting Capability

    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. 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.

  12. 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.

  13. 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.

  14. 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.

  15. Combined macro-meso scale modeling of sintering. Part II, Mesoscale simulations

    SciTech Connect

    TIKARE,VEENA; OLEVSKY,EUGENE A.; BRAGINSKY,MICHAEL V.

    2000-05-23

    A mesoscale kinetic Monte Carlo model is presented to simulate microstructural evolution during sintering of 2D complex microstructures which evolves by grain growth, pore migration and densification. No assumptions about the geometry of the evolving microstructure are made. The results of these simulations are used to generate sintering stress and normalize viscous bulk modulus for use in continuum level simulation of sintering. The advantage of these simulations is that they can be used to generate more accurate parameters as various assumptions regarding geometry and transport mechanism are made. The previous companion paper used the results from the mesoscale simulations to simulate shrinkage and warpage in sintering of bilayer ceramics.

  16. Large Eddy Simulation Embedded in Mesoscale Modeling of Convective Boundary Layers observed at the ARM SGP Central Facility

    NASA Astrophysics Data System (ADS)

    Chun, J.; Kang, S. L.

    2015-12-01

    We assess the performance of large eddy simulation (LES) embedded in a multi-nested mesoscale modeling framework with respect to observations at the Central Facility (CF) site of the Atmospheric Radiation Measurement (ARM) Southern Great Plains (SGP). Specifically for three different fair-weather days, evaluated are the temporal evolutions of temperature and water vapor in the afternoon convective boundary layer (CBL). From the two aspects of local surface and background atmospheric conditions, the causes of the deviations of LES results from observations are sought. In particular, we focus on the factors that critically influence on the surface and atmospheric conditions for LES through the multi-nested domains from grid spacing of 12 km down to 50 m. Also we identify the domain at the resolution of the so called "terra incognita", where the effective resolution or the spatial filter is comparable to the length scale of energy-containing turbulent eddies. The behavior of the "terra-incognita" domain and its influence on LES are investigated.

  17. Mesoscale organization in the Community Atmosphere Model (CAM)

    NASA Astrophysics Data System (ADS)

    Bacmeister, J. T.; Trier, S.; Davis, C. A.; Callaghan, P.

    2014-12-01

    Global climate simulations using CAM with horizontal resolution of 25 km begin to show interesting features that appear to be connected with mesoscale organization. These features include a reasonable climatology of tropical cyclones. Simulated precipitation in sub-Saharan West Africa is dominated by westward moving disturbances that show qualitative similarities to observations. Both the TCs and sub-Saharan disturbances appear to be dynamically-driven by resolved precipitation processes instead of parameterized convection. Disappointingly, simulations of propagating convection and related precipitation features in the US Midwest during summer are not significantly improved at 25 km resolution compared to 100 km resolution. This presentation will diagnose convective organization in CAM. Case-studies using nudging to re-analysis and regional-refinement over the US will be examined. These simulations will help to distinguish between errors due to large-scale forcing biases and those related to parameterization or dynamical deficiencies in CAM.

  18. Modelling the Shock Response of Polycrystals at the Mesoscale

    SciTech Connect

    Case, Simon; Horie, Yuki

    2006-07-28

    Simulation of the shock compression of a copper polycrystal at the mesoscale has been carried out using a Discrete Element code. Grains were aligned in three crystal orientations with respect to the shock direction; <100>, <110>, and <111>. The polycrystal had an average grain diameter of 14{mu}m and was impacted by a single crystal of copper at 200m/s. Results show the presence of a Particle Velocity Dispersion which attains its maximum magnitude of 8m/s at the plastic wave rise, and which is quantitatively of the same order as experimentally observed values. Non-planar elastic and plastic wave fronts are present. The shock front position distribution increases with propagation distance until its standard deviation is 0.4{mu}m at a propagation distance of 80{mu}m.

  19. 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

  20. 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

  1. Land-Atmosphere Interactions and Mesoscale Circulations in an Idealized Modeling Framework

    NASA Astrophysics Data System (ADS)

    Grant, L. D.; van den Heever, S. C.; Lu, L.

    2012-12-01

    Many studies have shown that land-atmosphere interactions and feedbacks have important implications for regional climate systems. For instance, clouds and precipitation alter radiation stream profiles, both of which influence land surface fluxes and change the partition between latent and sensible heating. This directly influences boundary layer temperature and moisture regimes and thus subsequent cloud and precipitation formation. Heterogeneous land surface characteristics, due for example to desertification, deforestation, or biomass burning -- all of which occur in Africa -- can also induce mesoscale circulations. Mesoscale circulations spatially impact boundary layer structure and convective initiation. We are investigating these interactions and feedbacks under an idealized framework using the Regional Atmospheric Modeling System (RAMS) version 6.0 and the Land Ecosystem-Atmosphere Feedback (LEAF) model version 3. Several-month simulations have been conducted at convection-resolving scales using periodic boundary conditions and different land surface types representative of surface characteristics in Africa. Results from these idealized simulations will be presented, with a focus on: (1) the influence of land surface properties including albedo, roughness length, soil moisture, and leaf area index on resultant mesoscale circulations and cloudy and precipitating regions; and (2) subsequent feedbacks to surface energy fluxes, shortwave and longwave radiation streams, and heating rates. Preliminary results indicate that both shallower boundary layer and deeper, more elevated mesoscale circulations are present due to the contrasting land surfaces. The circulations vary by season and influence convective development, precipitation, and surface and atmospheric thermodynamic structure. Potential implications for water cycle dynamics in Africa will be discussed.

  2. 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

  3. Integrating Visualizations into Modeling NEST Simulations.

    PubMed

    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.

  4. 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

  5. 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

  6. 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.

  7. 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.

  8. 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

  9. 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

  10. Mesoscale Modeling of the Inland Nocturnal Sea Breeze

    SciTech Connect

    Kurzeja, R.J.; Buckley, R.L.

    1995-09-12

    The mesoscale sea breeze has important consequences for many densely populated coastal environments, including convection initiation, aviation safety, and air quality. The sea breeze characteristics before and after sunset are markedly different (Sha et al 1993). A gravity current will form during the early afternoon due to the relatively large density difference between the land and sea air. During the afternoon, as the lighter land air is forced upward by the cooler dense sea air, Kelvin-Helmholtz (KH) billows often form along the interface, as well as thin regions of turbulent rising air, playing a crucial role in the mixing process (Simpson 1994). After sunset, the frontal zone expands as longwave radiation cools the surface which reduces vertical mixing. With further inland penetration, the sea breeze encounters increasingly stable air near the ground, resulting in the formation of an undular bore or cutoff vortex (Sha et al. 1993). It has been demonstrated that large-scale winds have profound effects on both the strength and inland penetration of sea breezes (Arritt 1993, among others). In general, offshore flow results in a sharper frontal discontinuity and less inland penetration, while onshore flow produces weaker fronts which may penetrate further inland. Most sea breeze studies have focused on its more dramatic daytime properties near the coast whereas inland nocturnal sea breezes have received much less attention. The reason for this neglect is a lack of good observational data in the boundary layer. Sha et al. (1991) note the necessity of high resolution data to capture the finer structures of the sea breeze. A unique opportunity to examine the nocturnal sea breeze became available at the Savannah River Site (SRS, located roughly 150 km from the Atlantic Ocean in southwestern South Carolina) during the Stable Boundary Layer Experiment (STABLE), 12-17 April, 1988. (Abstract Truncated)

  11. 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.

  12. 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.

  13. 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.

  14. Mesoscale model parameterizations for radiation and turbulent fluxes at the lower boundary

    NASA Astrophysics Data System (ADS)

    Somieski, Franz

    1988-11-01

    A radiation parameterization scheme for use in mesoscale models with orography and clouds was developed. Broadband parameterizations are presented for the solar and the terrestrial spectral ranges. They account for clear, turbid, or cloudy atmospheres. The scheme is one-dimensional in the atmosphere, but the effects of mountains (inclination, shading, elevated horizon) are taken into account at the surface. In the terrestrial brand, gray and black clouds are considered. The calculation of turbulent fluxes of sensible and latent heat and momentum at an inclined lower model boundary is described. Surface-layer similarity and the surface energy budget are used to evaluate the ground surface temperature. The total scheme is part of the mesoscale model MESOSCOP.

  15. Mesoscale meteorology - Theories, observations and models; Proceedings of the Advanced Study Institute, Bonas, Gers, France, July 13-31, 1982

    NASA Technical Reports Server (NTRS)

    Lilly, D. K. (Editor); Gal-Chen, T. (Editor)

    1983-01-01

    Among the topics discussed are mesoscale processes and variability, regional and cyclonic scale motions and their prediction modeling, fronts, mesoscale instabilities, buoyancy (gravity) waves and topographic forcing, buoyant convection, boundary layers, and observational technology. The specific issues investigated include methods for initializing mesoscale forecast models, an energy theory for the propagation of gravity currents, a theory for rain bands within extratropical cyclones, the morning glory as a nonlinear wave phenomenon, cumulus clouds, the prediction of severe convection, planetary boundary layer parameterization, and three-dimensional wind field analysis from Doppler radar data.

  16. 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.

  17. 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.

  18. 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.

  19. 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

  20. 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.

  1. 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.

  2. 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

  3. 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

  4. LES one-way coupling of nested grids using scale similarity model

    NASA Astrophysics Data System (ADS)

    Nozawa, Kojiro; Tamura, Tetsuro

    2010-11-01

    The method for coupling between nested grids with turbulence energy smoothly transferred is proposed for LES turbulent flows. In this method fluctuating velocity simulated in a coarse grid is imposed to a fine grid. As a result, time-sequential data of the grid-scale velocity fluctuation of the fine grid can be obtained utilizing the scale similarity concept [J. Bardina, J. H. Ferziger and W. C. Reynolds, AIAA Paper, No.80-1357, (1980)]. The a-priori test of a turbulent boundary layer flow over a rough surface is conducted to validate this method. In order to fulfill simulations of spatially developing turbulent boundary layer flows we apply the quasi-periodic boundary condition to the streamwise direction [K. Nozawa and T. Tamura, Proc. of the Turbulent Shear Flow Phenomena, vol.2, 443-448.(2001)]. In the test coarsely resolved velocity data which is generated filtering finely resolved LES data are applied for directly reproducing subgrid-scale components of the coarsely resolved LES. The reproduced fluctuation velocity agrees well with the true value which can be derived by subtracting the generated coarsely resolved velocity data from the finely resolved LES data. Also, the spectra of the reproduced streamwise fluctuation velocities at higher wave number range corresponding to the fine mesh size fit to the -5/3 power law for the inertial subrange. This method is expected to appropriately combine the meso-scale meteorological model with the LES model of urban scale.

  5. Vertical normal modes of a mesoscale model using a scaled height coordinate

    NASA Technical Reports Server (NTRS)

    Lipton, A. E.; Pielke, R. A.

    1986-01-01

    Vertical modes were derived for a version of the Colorado State Regional Atmospheric Mesoscale Modeling System. The impacts of three options for dealing with the upper boundary of the model were studied. The standard model formulation holds pressure constant at a fixed altitude near the model top, and produces a fastest mode with a speed of about 90 m/sec. An alternative formulation, which allows for an external mode, could require recomputation of vertical modes for every surface elevation on the horizontal grid unless the modes are derived in a particular way. These results have bearing on the feasibility of applying vertical mode initialization to models with scaled height coordinates.

  6. 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

  7. 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.

  8. 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.

  9. 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.

  10. 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.

  11. 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.

  12. 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.

  13. The Impact of Ignoring the Level of Nesting Structure in Nonparametric Multilevel Latent Class Models

    ERIC Educational Resources Information Center

    Park, Jungkyu; Yu, Hsiu-Ting

    2016-01-01

    The multilevel latent class model (MLCM) is a multilevel extension of a latent class model (LCM) that is used to analyze nested structure data structure. The nonparametric version of an MLCM assumes a discrete latent variable at a higher-level nesting structure to account for the dependency among observations nested within a higher-level unit. In…

  14. Gasdynamic modeling and parametric study of mesoscale internal combustion swing engine/generator systems

    NASA Astrophysics Data System (ADS)

    Gu, Yongxian

    The demand of portable power generation systems for both domestic and military applications has driven the advances of mesoscale internal combustion engine systems. This dissertation was devoted to the gasdynamic modeling and parametric study of the mesoscale internal combustion swing engine/generator systems. First, the system-level thermodynamic modeling for the swing engine/generator systems has been developed. The system performance as well as the potentials of both two- and four-stroke swing engine systems has been investigated based on this model. Then through parameterc studies, the parameters that have significant impacts on the system performance have been identified, among which, the burn time and spark advance time are the critical factors related to combustion process. It is found that the shorter burn time leads to higher system efficiency and power output and the optimal spark advance time is about half of the burn time. Secondly, the turbulent combustion modeling based on levelset method (G-equation) has been implemented into the commercial software FLUENT. Thereafter, the turbulent flame propagation in a generic mesoscale combustion chamber and realistic swing engine chambers has been studied. It is found that, in mesoscale combustion engines, the burn time is dominated by the mean turbulent kinetic energy in the chamber. It is also shown that in a generic mesoscale combustion chamber, the burn time depends on the longest distance between the initial ignition kernel to its walls and by changing the ignition and injection locations, the burn time can be reduced by a factor of two. Furthermore, the studies of turbulent flame propagation in real swing engine chambers show that the combustion can be enhanced through in-chamber turbulence augmentation and with higher engine frequency, the burn time is shorter, which indicates that the in-chamber turbulence can be induced by the motion of moving components as well as the intake gas jet flow. The burn time

  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. Perspective on Continuum Modeling of Mesoscale/ Macroscale Phenomena

    NASA Astrophysics Data System (ADS)

    Bammann, D. J.

    The attempt to model or predict the inelastic response or permanent deformation and failure observed in metals dates back over 180 years. Various descriptions of the post elastic response of metals have been proposed from the fields of physics, materials science (metallurgy), engineering, mechanics, and applied mathematics. The communication between these fields has improved and many of the modeling efforts today involve concepts from most or all of these fields. Early engineering description of post yield response treated the material as perfectly plastic — the material continues to deform with zero additional increase in load. These models became the basis of the mathematical theory of plasticity and were extended to account for hardening, unloading, and directional hardening. In contradistinction, rheological models treated the finite deformation of a solid similar to the deformation of a viscous fluid. In many cases of large deformation, rheological models have provided both adequate and accurate information about the deformed shape of a metal during many manufacturing processes. The treatment of geometric defects in solid bodies initiated within the mathematical theory of elasticity, the dislocation, introduced as an incompatible "cut" in a continuum body. This resulted in a very large body of literature devoted to the linear elastic study of dislocations, dislocation structures, and their interactions, and has provided essential information in the understanding of the "state" of a deformed material.

  17. 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.

  18. 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

  19. 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.

  20. 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.

  1. Mesoscale modeling of smoke radiative feedback over the Sahel region

    NASA Astrophysics Data System (ADS)

    Yang, Z.; Wang, J.; Ichoku, C. M.; Ellison, L.; Zhang, F.; Yue, Y.

    2013-12-01

    This study employs satellite observations and a fully-coupled meteorology-chemistry-aerosol model, Weather Research and Forecasting model with Chemistry (WRF-Chem) to study the smoke radative feedback on surface energy budget, boundary layer processes, and atmospheric lapse rate in February 2008 over the Sahel region. The smoke emission inventories we use come from various sources, including but not limited to the Fire Locating and Modeling of Burning Emissions (FLAMBE) developed by NRL and the Fire Energetic and Emissions Research (FEER) developed by NASA GSFC. Model performance is evaluated using numerous satellite and ground-based datasets: MODIS true color images, ground-based Aerosol Optical Depth (AOD) measurements from AERONET, MODIS AOD retrievals, and Cloud-Aerosol Lidar data with Orthogonal Polarization (CALIOP) atmospheric backscattering and extinction products. Specification of smoke injection height of 650 m in WRF-Chem yields aerosol vertical profiles that are most consistent with CALIOP observations of aerosol layer height. Statistically, 5% of the CALIPSO valid measurements of aerosols in February 2008 show aerosol layers either above the clouds or between the clouds, reinforcing the importance of the aerosol vertical distribution for quantifying aerosol impact on climate in the Sahel region. The results further show that the smoke radiative feedbacks are sensitive to assumptions of black carbon and organic carbon ratio in the particle emission inventory. Also investigated is the smoke semi-direct effect as a function of cloud fraction.

  2. 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

  3. 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.

  4. 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.

  5. Mesoscale Simulations of Reaction Initiation and Growth in HE Composites using PBRB model

    NASA Astrophysics Data System (ADS)

    Dwivedi, Sunil; Brennan, John; Horie, Yasuyuki

    2013-06-01

    Two-dimensional (2D) finite element based mesoscale simulation results are presented to predict reaction initiation and growth in high energy (HE) composites using the physics based reactive urn (PBRB) model. The HE composites are modeled as an ensemble of grains with statistically-distributed second phase particles. Their shock response is modeled with elastic-inelastic deformation coupled with the PBRB equation-of-state model. The inter-grain response is described by the contact-cohesive model that allows grain boundary failure and creation of free surface with friction characteristics during compressive shock loading. The heat generation due to the non-linear elastic, inelastic, cohesive, and friction energy dissipation into pre-assumed statistically-distributed hot spots, surface sublimation, and gas phase reaction are described as coupled mechanisms by the PBRB model yielding the mean stress as a function of the reaction at any given time. The simulations predict the time and run to detonation with reasonable agreement with data. The relative merits of 1D hot spot idealization, embodied in the PBRB model, for generic mesoscale simulations will be discussed. This work is supported in part by the DTRA Grant HDTRA1-12-1-0004 and ARL Grant W911NF-12-2-0053.

  6. 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.

  7. 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.

  8. 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.

  9. Prediction of tropical systems over Indian region using mesoscale model

    NASA Astrophysics Data System (ADS)

    Vaidya, S. S.; Mukhopadhyay, P.; Trivedi, D. K.; Sanjay, J.; Singh, S. S.

    The Advanced Regional Prediction System (ARPS) model developed at Center for Analysis and Prediction of Storms at Oklahoma State University, USA is used for simulation of monsoon depression and tropical cyclone over Indian region. The radiosonde data are included in the initial analyses and subsequently; the simulations are performed with 50km and 25km grid resolutions. Two sets of forecast experiments produced by two types of analyses (with radiosonde and without radiosonde data) are compared. It is found that predicted mean sea-level pressure of the depression becomes closer to mean sea level pressure reported in Indian Daily Weather Reports when initialized with analyses containing radiosonde data. The precipitation forecast also is improved when initialized with the analyses containing radiosonde data. The simulation of tropical cyclone with 25km grid resolution is able to simulate some subsynoptic scale features of the system.

  10. Estimation of parasitic losses in a proposed mesoscale resonant engine: Experiment and model

    NASA Astrophysics Data System (ADS)

    Preetham, B. S.; Anderson, M.; Richards, C.

    2014-02-01

    A resonant engine in which the piston-cylinder assembly is replaced by a flexible cavity is realized at the mesoscale using flexible metal bellows to demonstrate the feasibility of the concept. A four stroke motoring technique is developed and measurements are performed to determine parasitic losses. A non-linear lumped parameter model is developed to evaluate the engine performance. Experimentally, the heat transfer and friction effects are separated by varying the engine speed and operating frequency. The engine energy flow diagram showing the energy distribution among various parasitic elements reveals that the friction loss in the bellows is smaller than the sliding friction loss in a typical piston-cylinder assembly.

  11. An intercomparison of several diagnostic meteorological processors used in mesoscale air quality modeling

    SciTech Connect

    Vimont, J.C.; Scire, J.S.

    1994-12-31

    A major component, and area of uncertainty, in mesoscale air quality modeling, is the specification of the meteorological fields which affect the transport and dispersion of pollutants. Various options are available for estimating the wind and mixing depth fields over a mesoscale domain. Estimates of the wind field can be obtained from spatial and temporal interpolation of available observations or from diagnostic meteorological models, which estimate a meteorological field from available data and adjust those fields based on parameterizations of physical processes. A major weakness of these processors is their dependence on spatially and temporally sparse input data, particularly upper air data. These problems are exacerbated in regions of complex terrain and along the shorelines of large bodies of water. Similarly, the estimation of mixing depth is also reliant upon sparse observations and the parameterization of the convective and mechanical processes. The meteorological processors examined in this analysis were developed to drive different Lagrangian puff models. This paper describes the algorithms these processors use to estimate the wind fields and mixing depth fields.

  12. 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.

  13. 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://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/abs/2015EGUGA..17.1154P','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015EGUGA..17.1154P"><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/2012EGUGA..14.2527H','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2012EGUGA..14.2527H"><span id="translatedtitle">Impact of a Land Surface <span class="hlt">Model</span> (LSM) in a <span class="hlt">Mesoscale</span> <span class="hlt">Model</span> on the Prediction of Heavy Precipitation Events</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Hodur, R.; Jakubiak, B.</p> <p>2012-04-01</p> <p>High-resolution <span class="hlt">mesoscale</span> <span class="hlt">models</span> have shown considerable promise in the prediction of <span class="hlt">mesoscale</span> precipitation events. In particular, the Coupled Ocean/Atmosphere <span class="hlt">Mesoscale</span> Prediction System (COAMPS), developed for use by the U.S. Navy, and applied for real-time prediction by the Interdisciplinary Centre for Mathematical and Computational <span class="hlt">Modeling</span> (ICM), has shown skill in the prediction of significant <span class="hlt">mesoscale</span> rainfall events. Although the original version of COAMPS used a slab <span class="hlt">model</span> to represent the land surface, recent experiments have been conducted with a new version of COAMPS that uses the NOAH land surface <span class="hlt">model</span> (LSM) and the NASA Land Information System (LIS). The NOAH LSM uses 24 different land-use categories and 15 plant functional types. Each grid cell in COAMPS is comprised of a mosaic of up to 5 different land-use types, and those grid cells with a vegetation land-use type are further broken down into a maximum of 4 different plant functional types. Simulations have been performed using the slab- and NOAH LSM-versions of COAMPS on several significant rain events that occurred over Poland during the spring and summer of 2010. These simulations indicate that the land-surface interactions can alter the generation, maintenance, and decay of these rain systems, although these interactions are often small and subtle. This talk will address the configuration of two versions of COAMPS, a brief description of the rain events under study, and the results and validation of the tests that have been performed; along with suggestions for further work that is required in this area. Within the validation of the runs, a comparison will be given of the structure of the boundary layers that are formed using the slab- and NOAH LSM configurations of COAMPS, and how the differences in the boundary layer structures from these two versions of the <span class="hlt">model</span> affect the timing, strength, and distribution of these precipitation events.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2008MSMSE..16e5003S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2008MSMSE..16e5003S"><span id="translatedtitle">A three-dimensional <span class="hlt">meso-scale</span> computer <span class="hlt">modeling</span> for bubble growth in metals</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Suzudo, T.; Kaburaki, H.; Itakura, M.; Wakai, E.</p> <p>2008-07-01</p> <p>A new <span class="hlt">meso-scale</span> three-dimensional computer <span class="hlt">model</span> has been proposed to enhance the <span class="hlt">modeling</span> capability of the bubble growth in metals, particularly helium bubble growth under conditions of post-irradiation annealing. We assume that the bubble growth is <span class="hlt">modeled</span> by a process driven by energy minimization of the surface energy and thermal fluctuation within the framework of a Monte Carlo simulation method. We found that it is possible to simulate growing bubbles following the ideal gas law and in equilibrium with the surface tension. The simulation results show good agreement with some experimental evidence, in particular, of the log-normal bubble-size distribution. The extension of the <span class="hlt">model</span> to the bubble growth on grain boundaries with reference to helium embrittlement has succeeded in reproducing a particular bubble shape observed in experiments.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2005PhDT........30V','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2005PhDT........30V"><span id="translatedtitle">Essays on pricing dynamics, price dispersion, and <span class="hlt">nested</span> logit <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>Verlinda, Jeremy Alan</p> <p></p> <p>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 <span class="hlt">modeling</span> 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 <span class="hlt">nested</span> logit <span class="hlt">modelling</span>, 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</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2003EAEJA.....2689B','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2003EAEJA.....2689B"><span id="translatedtitle">Assimilation of Sea Surface Temperature in a doubly, two-way <span class="hlt">nested</span> primitive equation <span class="hlt">model</span> of the Ligurian Sea</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Barth, A.; Alvera-Azcarate, A.; Rixen, M.; Beckers, J.-M.; Testut, C.-E.; Brankart, J.-M.; Brasseur, P.</p> <p>2003-04-01</p> <p>The GHER 3D primitive equation <span class="hlt">model</span> is implemented with three different resolutions: a low resolution <span class="hlt">model</span> (1/4^o) covering the whole Mediterranean Sea, an intermediate resolution <span class="hlt">model</span> (1/20^o) of the Liguro-Provençal basin and a high resolution <span class="hlt">model</span> (1/60^o) simulating the fine <span class="hlt">mesoscale</span> structures in the Ligurian Sea. Boundary conditions and the averaged fields (feedback) are exchanged between two successive <span class="hlt">nesting</span> levels. The <span class="hlt">model</span> of the Ligurian Sea is also coupled with the assimilation package SESAM. It allows to assimilate satellite data and in situ observations using the local adaptative SEEK (Singular Evolutive Extended Kalman) filter. Instead of evolving the error space by the numerically expensive Lyapunov equation, a simplified algebraic equation depending on the misfit between observation and <span class="hlt">model</span> forecast is used. Starting from the 1st January 1998 the low and intermediate resolution <span class="hlt">models</span> are spun up for 18 months. The initial conditions for the Ligurian Sea are interpolated from the intermediate resolution <span class="hlt">model</span>. The three <span class="hlt">models</span> are then integrated until August 1999. During this period AVHRR Sea Surface Temperature of the Ligurian Sea is assimilated. The results are validated by using CTD and XBT profiles of the SIRENA cruise from the SACLANT Center. The overall objective of this study is pre-operational. It should help to identify limitations and weaknesses of forecasting methods and to suggest improvements of existing operational <span class="hlt">models</span>.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2008JGRE..113.0A12T','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2008JGRE..113.0A12T"><span id="translatedtitle"><span class="hlt">Mesoscale</span> and large-eddy simulation <span class="hlt">model</span> studies of the Martian atmosphere in support of Phoenix</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Tyler, Daniel; Barnes, Jeffrey R.; Skyllingstad, Eric D.</p> <p>2008-08-01</p> <p>In late May of 2008, the NASA/JPL Phoenix spacecraft will touch down near its targeted landing site on Mars (68.2°N, 126.6°W). Entry, descent, and landing (EDL) occurs in the late afternoon (~1630 hours local solar time (LST)) during late northern spring (Ls ~ 78°). Using a <span class="hlt">mesoscale</span> and a large-eddy simulation (LES) <span class="hlt">model</span>, we have investigated the range of conditions that might be encountered in the lower atmosphere during EDL. High-resolution (~18 km) results from the Oregon State University Mars MM5 (OSU MMM5) are used to understand the hazards from the transient circulations prominent during this season. Poleward of ~80°N these storms produce strong winds (~35 m s-1) near the ground; however, owing to the synoptic structure of these storms, and the deep convective mixed layer equatorward of the seasonal cap boundary during EDL, our <span class="hlt">modeling</span> suggests the spacecraft would not be in winds stronger than ~20 m s-1 at parachute separation. The storm-driven variability is much weaker at Phoenix latitudes than it is poleward of the seasonal cap edge (result from an extensive sensitivity study). The OSU MLES <span class="hlt">model</span> is used to explicitly simulate the hazards of convection and atmospheric turbulence at very high resolution (100 m). This <span class="hlt">modeling</span> suggests that an upper bound for the maximum expected horizontal-mean atmospheric turbulent kinetic energy (TKE) is ~12 m2 s-2, seen ~3 km above the ground at ~1430 hours LST. TKE amplitudes are greatest when the horizontal mean wind is large (shear production) and/or the surface albedo is low (a lower albedo enhances buoyancy production, mimicking decreased atmospheric stability after a storm advects colder air into the region). LES simulations predict deep mixed layers (~6-7 km), ~1.5 km deeper than the <span class="hlt">mesoscale</span> <span class="hlt">model</span> (~5 km). <span class="hlt">Mesoscale</span> <span class="hlt">modeling</span> suggests that the actual landing site differs meteorologically from other longitudes (larger-amplitude diurnal wind cycle), a consequence of the strong thermal circulations that are</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_6");'>6</a></li> <li><a href="#" onclick='return showDiv("page_7");'>7</a></li> <li class="active"><span>8</span></li> <li><a href="#" onclick='return showDiv("page_9");'>9</a></li> <li><a href="#" onclick='return showDiv("page_10");'>10</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_8 --> <div id="page_9" 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_7");'>7</a></li> <li><a href="#" onclick='return showDiv("page_8");'>8</a></li> <li class="active"><span>9</span></li> <li><a href="#" onclick='return showDiv("page_10");'>10</a></li> <li><a href="#" onclick='return showDiv("page_11");'>11</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="161"> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2002PhDT.......132D','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2002PhDT.......132D"><span id="translatedtitle">A test for evaluating the downscaling ability of one-way <span class="hlt">nested</span> regional climate <span class="hlt">models</span>: The Big-Brother Experiment</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Denis, Bertrand</p> <p></p> <p>The purpose of this thesis is to evaluate the downscaling ability of one-way <span class="hlt">nesting</span> regional climate <span class="hlt">models</span> (RCM). To do this, a rigorous and well-defined experiment for assessing the reliability of the one-way <span class="hlt">nesting</span> approach is developed. This experiment, baptised the Big-Brother Experiment (BBE), is used for addressing some important one-way <span class="hlt">nesting</span> issues. The first part of this work is dedicated to the development of a scale decomposition tool employed for the BBE. This tool involves a new spectral analysing technique suitable for two-dimensional fields on limited-area domains, and is based on the discrete cosine transform (DCT). It is used for degrading the spatial resolution of the lateral boundary conditions (LBC) used to drive the Canadian RCM (CRCM), for extracting <span class="hlt">mesoscale</span> features from the atmospheric fields, and for regional validation, and producing power spectra. The second part of the thesis describes the BBE framework and its first results. The BBE consists in first establishing a reference virtual-reality climate from an RCM simulation using a large and high-resolution domain. This simulation is called the "Big Brother". This big-brother simulation is then degraded toward the resolution of today's global objective analyses (OA) and/or global climate <span class="hlt">models</span> (GCM) by removing the short scales. The resulting fields are then used as <span class="hlt">nesting</span> data to drive an RCM (called the "Little Brother") which is integrated at the same high-resolution as the Big Brother, but over a sub-area of the big-brother domain. The climate statistics of the Little Brother are then compared with those of the big-brother simulation over the little-brother domain. Differences between the two climates can thus be unambiguously attributed to errors associated with the dynamical downscaling technique, and not to <span class="hlt">model</span> errors nor to observation limitations. The results for a February simulation shows that the Canadian RCM, using a factor of 6 between the <span class="hlt">model</span> and the LBC spatial</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('https://www.ncbi.nlm.nih.gov/pubmed/23584035','PUBMED'); return false;" href="https://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="https://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.</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://ntrs.nasa.gov/search.jsp?R=20030054450&hterms=modis+land+surface+temperature&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D10%26Ntt%3D%2528%2528%2528modis%2Bland%2529%2Bsurface%2529%2Btemperature%2529','NASA-TRS'); return false;" href="http://ntrs.nasa.gov/search.jsp?R=20030054450&hterms=modis+land+surface+temperature&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D10%26Ntt%3D%2528%2528%2528modis%2Bland%2529%2Bsurface%2529%2Btemperature%2529"><span id="translatedtitle">Use of MODIS Land and Sea Surface Temperatures to Initialize <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>Arnold, James E. (Technical Monitor); Lapenta, William M.; Haines, Stephanie; Jedlovec, Gary; Mackaro, Scott</p> <p>2003-01-01</p> <p>As computer power continues to increase, <span class="hlt">mesoscale</span> <span class="hlt">models</span> are initialized at all hours of the day and continue to be run at higher and higher spatial resolutions. As a result, initializing land surface temperature can be problematic. The majority of research-based <span class="hlt">models</span> are initialized at 00 and 12 UTC when upper air observations and reanalysis fields are available. The landsea surface temperatures are then set equal to the two-meter air temperature produced by the preprocessor analysis system. This particular procedure might be valid in the early morning hours just prior to sunrise, but it becomes less valid during the remainder of the diurnal cycle. Operational <span class="hlt">models</span>, such as the Rapid Update Cycle run at the National Centers for Environmental Prediction (NCEP), are initialized every hour on a daily basis. This presents a unique challenge to the initial specification of the land temperature, especially during the first several hours of the solar heating cycle when land and overlying air temperatures are far from being the same. Another issue that needs to be addressed is the spatial variability of land surface temperature. By early next year, the NCEP operational Eta <span class="hlt">model</span> will be employed at 8 km resolution. Methods to accurately specify the initial land surface temperature at such high resolution need to be explored. This paper presents the results of using data from the NASA Moderate Imaging Sensor aboard the TERRA Satellite to initialize land and sea surface temperatures within the Pennsylvania State University/National Center for Atmospheric Research (PSU/NCAR) 5'th generation <span class="hlt">Mesoscale</span> <span class="hlt">Model</span> (MM5). We have simulated a northern Gulf Coast sea breeze case to demonstrate the utility of using the MODIS data to initialize both the land and sea surface temperature fields. <span class="hlt">Model</span> grid configurations of 12-, 4-, and l-km are employed.</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/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('https://www.ncbi.nlm.nih.gov/pubmed/10842945','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/10842945"><span id="translatedtitle">Assessment of the <span class="hlt">nested</span> grid <span class="hlt">model</span> estimates for driving regional visibility <span class="hlt">models</span> in the southwestern United States.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Pai, P; Farber, R J; Karamchandani, P; Tombach, I</p> <p>2000-05-01</p> <p>The <span class="hlt">Nested</span> Grid <span class="hlt">Model</span> (NGM) is a primitive-equation meteorological <span class="hlt">model</span> that is routinely exercised over North America for forecasting purposes by the National Meteorological Center. While prognostic meteorological <span class="hlt">models</span> are being increasingly used to drive air quality <span class="hlt">models</span>, their use in conducting annual simulations requires significant resources. NGM estimates of wind fields and other meteorological variables provide an attractive alternative since they are typically archived and readily available for an entire year. Preliminary evaluation of NGM winds during the summer of 1992 for application to the region surrounding the Grand Canyon National Park showed serious shortcomings. The NGM winds along the borders between California, Arizona and Mexico tend to be northwesterly with a speed of about 6 m/sec, while the observed flow is predominantly southerly at about 2-5 m/sec. The <span class="hlt">mesoscale</span> effect of a thermal low pressure area over the highly heated Southern California and western Arizona deserts does not appear to be represented by the NGM because of its coarse resolution and the use of sparse observations in that region. Tracer simulations and statistical evaluation against special high resolution observations of winds in the southwest United States clearly demonstrate the northwest bias in NGM winds and its adverse effect on predictions of an air quality <span class="hlt">model</span>. The "enhanced" NGM winds, in which selected wind observations are incorporated in the NGM winds using a diagnostic meteorological <span class="hlt">model</span> provide additional confirmation on the primary cause of the northwest bias. This study has demonstrated that in situations where limited resources prevent the use of prognostic meteorological <span class="hlt">models</span>, previously archived coarse resolution wind fields in which additional observations are incorporated to correct known biases provide an attractive option.</p> </li> <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://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> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016Geomo.256...68V','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016Geomo.256...68V"><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://www.osti.gov/scitech/servlets/purl/1121927','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/servlets/purl/1121927"><span id="translatedtitle">LDRD final report : <span class="hlt">mesoscale</span> <span class="hlt">modeling</span> of dynamic loading of heterogeneous materials.</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Robbins, Joshua; Dingreville, Remi Philippe Michel; Voth, Thomas Eugene; Furnish, Michael David</p> <p>2013-12-01</p> <p>Material response to dynamic loading is often dominated by microstructure (grain structure, porosity, inclusions, defects). An example critically important to Sandia's mission is dynamic strength of polycrystalline metals where heterogeneities lead to localization of deformation and loss of shear strength. Microstructural effects are of broad importance to the scientific community and several institutions within DoD and DOE; however, current <span class="hlt">models</span> rely on inaccurate assumptions about mechanisms at the sub-continuum or <span class="hlt">mesoscale</span>. Consequently, there is a critical need for accurate and robust methods for <span class="hlt">modeling</span> heterogeneous material response at this lower length scale. This report summarizes work performed as part of an LDRD effort (FY11 to FY13; project number 151364) to meet these needs.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015OcSci..11..667L','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015OcSci..11..667L"><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=drag&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=78793294&CFTOKEN=55872027','EPA-EIMS'); return false;" href="http://cfpub.epa.gov/si/si_public_record_report.cfm?dirEntryId=146423&keyword=drag&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=78793294&CFTOKEN=55872027"><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://adsabs.harvard.edu/abs/2014EGUGA..1614351S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014EGUGA..1614351S"><span id="translatedtitle">High-resolution spatial distribution of temperature over Berlin simulated by the <span class="hlt">mesoscale</span> <span class="hlt">model</span> METRAS and comparison with measured data</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Sodoudi, Sahar; Schäfer, Kerstin; Grawe, David; Petrik, Ronny; Heinke Schlünzen, K.</p> <p>2014-05-01</p> <p>The world's population is projected to increase in the next decades especially in urban areas. Additionally, the living conditions are affected largely by the local urban climate. The urban climate is a complex local system which might change differently than the regional climate. Studying the spatial distribution of air temperature and urban heat island intensity is one of the major concerns in the climate change scenarios. Due to the expected higher frequency of heat waves in the future and the related heat stress, high resolution distribution of air temperature is an important key for urban planning and development. In this study the non-hydrostatic <span class="hlt">Mesoscale</span> Transport and Fluid <span class="hlt">Model</span> (METRAS) developed at the University of Hamburg is used to simulate the air temperature for the urban area of Berlin. The forcing data have been derived from the ECMWF reanalysis data. We have used three <span class="hlt">nested</span> domains (resolution of 4 km, 1 km, 200 m) to simulate the temperature in Berlin. Evaluation of these <span class="hlt">mesoscale</span> <span class="hlt">model</span> results is challenging for urban areas, due to the sparse and heterogeneous distribution of meteorological stations and the heterogeneous land cover in urban areas. The Meteorological Institute of the Free University of Berlin organized six measurement campaigns in 2012. Measurements were taken at 31 different routes through Berlin using mobile measurement systems. In comparison with data from permanent weather stations the mobile measurements show a general overestimation of temperature and underestimation of relative humidity values. This may be the result of the different land cover types and places, where the mobile measurements and the stationary measurements were taken. The highly resolved (200 m) simulated air temperature from METRAS has been verified for three different selected summer days in 2012 with different pressure patterns over Berlin. For the <span class="hlt">model</span> evaluation, the data from the measuring campaign and 34 permanent stations have been used. The</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2008JHyd..353..322M','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2008JHyd..353..322M"><span id="translatedtitle"><span class="hlt">Modelling</span> the water balance of a <span class="hlt">mesoscale</span> catchment basin using remotely sensed land cover data</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Montzka, Carsten; Canty, Morton; Kunkel, Ralf; Menz, Gunter; Vereecken, Harry; Wendland, Frank</p> <p>2008-05-01</p> <p>SummaryHydrological <span class="hlt">modelling</span> of <span class="hlt">mesoscale</span> catchments is often adversely affected by a lack of adequate information about specific site conditions. In particular, digital land cover data are available from data sets which were acquired on a European or a national scale. These data sets do not only exhibit a restricted spatial resolution but also a differentiation of crops and impervious areas which is not appropriate to the needs of <span class="hlt">mesoscale</span> hydrological <span class="hlt">models</span>. In this paper, the impact of remote sensing data on the reliability of a water balance <span class="hlt">model</span> is investigated and compared to <span class="hlt">model</span> results determined on the basis of CORINE (Coordination of Information on the Environment) Land Cover as a reference. The aim is to quantify the improved <span class="hlt">model</span> performance achieved by an enhanced land cover representation and corresponding <span class="hlt">model</span> modifications. Making use of medium resolution satellite imagery from SPOT, LANDSAT ETM+ and ASTER, detailed information on land cover, especially agricultural crops and impervious surfaces, was extracted over a 5-year period (2000-2004). Crop-specific evapotranspiration coefficients were derived by using remote sensing data to replace grass reference evapotranspiration necessitated by the use of CORINE land cover for rural areas. For regions classified as settlement or industrial areas, degrees of imperviousness were derived. The data were incorporated into the hydrological <span class="hlt">model</span> GROWA (large-scale water balance <span class="hlt">model</span>), which uses an empirical approach combining distributed meteorological data with distributed site parameters to calculate the annual runoff components. Using satellite imagery in combination with runoff data from gauging stations for the years 2000-2004, the actual evapotranspiration calculation in GROWA was methodologically extended by including empirical crop coefficients for actual evapotranspiration calculations. While GROWA originally treated agricultural areas as homogeneous, now a consideration and differentiation</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014EGUGA..1611609W','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014EGUGA..1611609W"><span id="translatedtitle">Evolution of conserved variables related to storm cells during severe convection 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>Weijenborg, Chris; Chagnon, Jeffrey; Friederichs, Petra; Gray, Suzanne; Hense, Andreas</p> <p>2014-05-01</p> <p>The WEX-MOP project aims at a next generation ensemble prediction system for the <span class="hlt">mesoscale</span>. One goal of WEX-MOP is to quantify the role of conserved quantities during extreme convective weather. Conserved variables might offer new insight in the predictability of those events. An important conserved quantity is potential vorticity (PV), a fundamental property of the atmospheric flow on synoptic and planetary scales. However, investigations thereof on the atmospheric <span class="hlt">mesoscale</span> are relatively new. PV has a close relation to rotation and balance, which is important in storm dynamics. Here we characterize the evolution of storm cells in terms of PV to provide new insights into storm dynamics. Tracking of storm cells has been frequently performed using radar and/or satellite data. It received less attention using <span class="hlt">model</span> data. We present storm cell tracks for two cases of severe convection in June 2011 simulated using the non hydrostatic COSMO-DE weather <span class="hlt">model</span>. The two cases have a very different background: on 5 June 2011 the convection was primarily locally forced by CAPE, while on 22 June there was strong forcing due to a cold front. For each of the two cases vertical velocity maxima are tracked. High intensity cells in both cases show a high correlation between PV and vertical velocity anomalies. This has been attributed to a strong environment storm relative helicity and/or CAPE close to the surface. For both cases there is a high variability in the cell characteristics. However, the PV anomalies on 22 June are larger than those on 5 June and have a higher correlation between vertical velocity and PV, consistent with the larger wind shear and helicity in the environment at this day. Study of further cases is necessary to test the hypothesis that a high helicity environment leads to more intense long lasting cells.</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> </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_7");'>7</a></li> <li><a href="#" onclick='return showDiv("page_8");'>8</a></li> <li class="active"><span>9</span></li> <li><a href="#" onclick='return showDiv("page_10");'>10</a></li> <li><a href="#" onclick='return showDiv("page_11");'>11</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_9 --> <div id="page_10" 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_8");'>8</a></li> <li><a href="#" onclick='return showDiv("page_9");'>9</a></li> <li class="active"><span>10</span></li> <li><a href="#" onclick='return showDiv("page_11");'>11</a></li> <li><a href="#" onclick='return showDiv("page_12");'>12</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="181"> <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://www.ncbi.nlm.nih.gov/pubmed/21516903','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/21516903"><span id="translatedtitle">Leatherback <span class="hlt">nests</span> increasing significantly in Florida, USA; trends assessed over 30 years using multilevel <span class="hlt">modeling</span>.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Stewart, Kelly; Sims, Michelle; Meylan, Anne; Witherington, Blair; Brost, Beth; Crowder, Larry B</p> <p>2011-01-01</p> <p>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, <span class="hlt">nest</span> counts are the most reliable way of assessing trends. We determined the rate of growth for leatherback turtle (Dermochelys coriacea) <span class="hlt">nest</span> numbers in Florida (USA) using a multilevel Poisson regression. We <span class="hlt">modeled</span> <span class="hlt">nest</span> 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 <span class="hlt">modeling</span> approach is ideal for <span class="hlt">nest</span> count data because it recognizes the hierarchical structure of the data while incorporating variables related to survey effort. <span class="hlt">Nesting</span> 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 <span class="hlt">nests</span> has been increasing by 10.2% per year since 1979. Despite being a small population (probably < 1000 individuals), this <span class="hlt">nesting</span> 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 <span class="hlt">nesting</span> beaches. However, <span class="hlt">nesting</span> 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</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/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> <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://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://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://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=vegetation&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D80%26Ntt%3Dvegetation','NASA-TRS'); return false;" href="http://ntrs.nasa.gov/search.jsp?R=20100031067&hterms=vegetation&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D80%26Ntt%3Dvegetation"><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/abs/2014AGUFMEP11B..07C','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014AGUFMEP11B..07C"><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/abs/2008AnGeo..26.3545C','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2008AnGeo..26.3545C"><span id="translatedtitle">Simulation of hailstorm event using <span class="hlt">Mesoscale</span> <span class="hlt">Model</span> MM5 with modified cloud microphysics scheme</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Chatterjee, P.; Pradhan, D.; de, U. K.</p> <p>2008-11-01</p> <p><span class="hlt">Mesoscale</span> <span class="hlt">model</span> MM5 (Version 3.5) with some modifications in the cloud microphysics scheme of Schultz (1995), has been used to simulate two hailstorm events over Gangetic Plain of West Bengal, India. While the first event occurred on 12 March 2003 and the hails covered four districts of the state of West Bengal, India, the second hailstorm event struck Srinikatan (22.65° N, 87.7° E) on 10 April 2006 at 11:32 UT and it lasted for 2 3 min. Both these events can be simulated, if the same modifications are introduced in the cloud microphysics scheme of Schultz. However, the original scheme of Schultz cannot simulate any hail. The results of simulation were compared with the necessary products of Doppler Weather Radar (DWR) located at Kolkata (22.57° N, 88.35° E). <span class="hlt">Model</span> products like reflectivity, graupel and horizontal wind are compared with the corresponding products of DWR. The pattern of hail development bears good similarity between <span class="hlt">model</span> output and observation from DWR, if necessary modifications are introduced in the <span class="hlt">model</span>. The <span class="hlt">model</span> output of 24 h accumulated rain from 03:00 UT to next day 03:00 UT has also been compared with the corresponding product of the satellite TRMM.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/24988781','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/24988781"><span id="translatedtitle">Habitat <span class="hlt">modeling</span> in high-gradient streams: the <span class="hlt">mesoscale</span> approach and application.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Vezza, Paolo; Parasiewicz, Piotr; Spairani, Michele; Comoglio, Claudio</p> <p>2014-06-01</p> <p>This study aimed to set out a new methodology for habitat <span class="hlt">modeling</span> in high-gradient streams. The methodology is based on the <span class="hlt">mesoscale</span> approach of the MesoHABSIM simulation system and can support the definition and assessment of environmental flow and habitat restoration measures. Data from 40 study sites located within the mountainous areas of the Valle d'Aosta, Piemonte and Liguria regions (Northwest Italy) were used in the analysis. To adapt MesoHABSIM to high-gradient streams, we first modified the data collection strategy to address the challenging conditions of surveys by using GIS and mobile mapping techniques. Secondly, we built habitat suitability <span class="hlt">models</span> at a regional scale to enable their transferability among different streams with different morphologies. Thirdly, due to the absence of stream gauges in headwaters, we proposed a possible way to simulate flow time series and, therefore, generate habitat time series. The resulting method was evaluated in terms of time expenditure for field data collection and habitat-<span class="hlt">modeling</span> potentials, and it represents a specific improvement of the MesoHABSIM system for habitat <span class="hlt">modeling</span> in high-gradient streams, where other commonly used methodologies can be unsuitable. Through its application at several study sites, the proposed methodology adapted well to high-gradient streams and allowed the: (1) definition of fish habitat requirements for many streams simultaneously, (2) <span class="hlt">modeling</span> of habitat variation over a range of discharges, and (3) determination of environmental standards for mountainous watercourses.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016CompM..58..635H','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016CompM..58..635H"><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>2016-10-01</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://www.ncbi.nlm.nih.gov/pubmed/24988781','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/24988781"><span id="translatedtitle">Habitat <span class="hlt">modeling</span> in high-gradient streams: the <span class="hlt">mesoscale</span> approach and application.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Vezza, Paolo; Parasiewicz, Piotr; Spairani, Michele; Comoglio, Claudio</p> <p>2014-06-01</p> <p>This study aimed to set out a new methodology for habitat <span class="hlt">modeling</span> in high-gradient streams. The methodology is based on the <span class="hlt">mesoscale</span> approach of the MesoHABSIM simulation system and can support the definition and assessment of environmental flow and habitat restoration measures. Data from 40 study sites located within the mountainous areas of the Valle d'Aosta, Piemonte and Liguria regions (Northwest Italy) were used in the analysis. To adapt MesoHABSIM to high-gradient streams, we first modified the data collection strategy to address the challenging conditions of surveys by using GIS and mobile mapping techniques. Secondly, we built habitat suitability <span class="hlt">models</span> at a regional scale to enable their transferability among different streams with different morphologies. Thirdly, due to the absence of stream gauges in headwaters, we proposed a possible way to simulate flow time series and, therefore, generate habitat time series. The resulting method was evaluated in terms of time expenditure for field data collection and habitat-<span class="hlt">modeling</span> potentials, and it represents a specific improvement of the MesoHABSIM system for habitat <span class="hlt">modeling</span> in high-gradient streams, where other commonly used methodologies can be unsuitable. Through its application at several study sites, the proposed methodology adapted well to high-gradient streams and allowed the: (1) definition of fish habitat requirements for many streams simultaneously, (2) <span class="hlt">modeling</span> of habitat variation over a range of discharges, and (3) determination of environmental standards for mountainous watercourses. PMID:24988781</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016CompM.tmp...69H','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016CompM.tmp...69H"><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/2009AGUFM.A33H..03E','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2009AGUFM.A33H..03E"><span id="translatedtitle">Analysis of Numerical <span class="hlt">Mesoscale</span> <span class="hlt">Model</span> Data for Wind Integration Studies in the United States</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Elliott, D.; Schwartz, M. N.; Lew, D.; Corbus, D.; Scott, G.; Haymes, S.; Wan, Y.</p> <p>2009-12-01</p> <p>The Western Wind and Solar Integration Study (WWSIS) and the Eastern Wind Integration and Transmission Study (EWITS) are enhancing energy security by defining operating impacts due to large penetrations of renewable energy. The backbones of these studies are the large and consistent wind speed and power production data sets valid at 80 m and/or 100 m above ground derived from numerical <span class="hlt">mesoscale</span> <span class="hlt">models</span> for the years 2004-2006 and aggregated into wind power plants. The horizontal and temporal resolution of the data is 2 km and 10 minutes, respectively. The WWSIS data set was produced by 3TIER and the EWITS data set was produced by AWS Truewind under contract to the National Renewable Energy Laboratory (NREL). These data sets, which are available at http://www.nrel.gov/wind/integrationdatasets/, were designed for spatial and temporal comparison of sites for geographic diversity and load correlation and to provide estimates of power production from hypothetical wind plants. These data sets do not depict all possible wind plant sites nor should the data be used as the sole basis of project investment. NREL has performed a quality control check on the annual wind speed and power parameters and will conduct a detailed validation of the seasonal, diurnal, and geographic distribution patterns of the <span class="hlt">model</span> data. The purposes of the analysis are to identify any anomalies in the data, to assess the regional accuracy of the data, and if warranted, to modify the data sets. One conclusion from the quality control exercise is that there are many details such as spatial and temporal discontinuities in the <span class="hlt">model</span> output produced during post simulation processing that need to be examined in addition to the overall accuracy of the data. In this paper, we will present the results of the analysis of the <span class="hlt">mesoscale</span> <span class="hlt">model</span> data used for the Western and Eastern United States integration studies. We will discuss the validation of the data sets, including comparisons with validated wind maps</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://adsabs.harvard.edu/abs/2012MS%26E...27a2077D','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2012MS%26E...27a2077D"><span id="translatedtitle">An integrated <span class="hlt">meso-scale</span> numerical <span class="hlt">model</span> of melting and solidification in laser welding</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Duggan, G.; Tong, M.; Browne, D. J.</p> <p>2012-01-01</p> <p>The authors present an integrated numerical <span class="hlt">model</span> for the simulation of laser spot welding of an aluminium alloy at <span class="hlt">meso-scale</span> in 2D. This <span class="hlt">model</span> deals with the melting of the parent materials which form the weld pool and the subsequent solidification of the liquid metal in the pool, during the welding process. The melting of the parent materials due to the applied heating power is an important phenomenon, which determines the conditions at the onset of solidification, such as the geometry of the weld pool and the distribution of the temperature field. An enthalpy method is employed to predict the melting during the heating phase of welding. A Gaussian distribution is used to <span class="hlt">model</span> the heat input from the laser. Once the laser beam is switched off and the melting halts, solidification commences. The UCD front tracking <span class="hlt">model</span> [1,2] for alloy solidification is applied to predict the advancement of the columnar dendritic front, and a volume-averaging formulation is used to simulate nucleation and growth of equiaxed dendrites. A mechanical blocking criterion is used to define dendrite coherency, and the columnar-to-equiaxed transition within the weld pool is predicted.</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_8");'>8</a></li> <li><a href="#" onclick='return showDiv("page_9");'>9</a></li> <li class="active"><span>10</span></li> <li><a href="#" onclick='return showDiv("page_11");'>11</a></li> <li><a href="#" onclick='return showDiv("page_12");'>12</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_10 --> <div id="page_11" 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_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> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="201"> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016LPICo1921.6404D','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016LPICo1921.6404D"><span id="translatedtitle">Interrogating Heterogeneous Compaction of Meteoritic Material at the <span class="hlt">Mesoscale</span> Using Analog Experiments and Numerical <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>Derrick, J. G.; Rutherford, M. E.; Davison, T. M.; Eakins, D. E.; Collins, G. S.</p> <p>2016-08-01</p> <p>We compare experimental results and simulations of <span class="hlt">mesoscale</span> shock compaction, as potential analogs to the shock metamorphism of meteoritic material. Qualitative agreement suggests the experiments are useful analogs to study meteoritic compaction.</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://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://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/2007AGUFM.H13F1653G','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2007AGUFM.H13F1653G"><span id="translatedtitle">Simulation of CO2 dispersion in the atmospheric boundary layer using 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>Granvold, P. W.; Chow, F. K.; Oldenburg, C. M.</p> <p>2007-12-01</p> <p>The consequences of unexpected releases of CO2 from underground carbon sequestration sites must be understood before large-scale carbon capture and storage projects are implemented. Carbon dioxide gas can migrate through faults, fractures, or abandoned wells that penetrate the subsurface storage site and provide a pathway to the ground surface. Though such leakage is typically slow and in small amounts, CO2 can accumulate at the ground surface because it is denser than the surrounding atmosphere. Such accumulation presents health risks for humans and animals in the vicinity, and can cause damage to crops, trees, and other vegetation. Because atmospheric dispersion of CO2 is driven by gravity and ambient wind conditions, the danger from CO2 is greatest in regions with topographic depressions where the dense gas can pool, or under stably- stratified background atmospheric conditions which further inhibit mixing and dilution of the gas. We are developing a simulation tool for predictions of CO2 releases from underground storage sites in a <span class="hlt">mesoscale</span> atmospheric <span class="hlt">model</span>. The <span class="hlt">model</span> solves the compressible fluid flow equations, and has been modified to account for transport of dense gases. Example simulations from sources of different release strengths over various topography and background atmospheric conditions illustrate the behavior of the <span class="hlt">model</span> and its utility for risk assessment and certification of carbon sequestration sites.</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/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.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="https://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://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://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('https://dceg.cancer.gov/tools/analysis/nested-cohort','NCI'); return false;" href="https://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/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://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.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/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://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/2015APS..SHK.K6004H','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015APS..SHK.K6004H"><span id="translatedtitle">On <span class="hlt">mesoscale</span> methods to enhance full-stress continuum <span class="hlt">modeling</span> of porous compaction</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Herbold, Eric B.; Swift, Damian C.; Kraus, Richard G.; Homel, Michael; Lorenzana, Hector E.</p> <p>2015-06-01</p> <p>The dynamic compaction of initially porous material is typically treated in continuum dynamics simulations via adjustments to the scalar equation of state (EOS) of the bulk, porous material relative to that of the solid. However, the behavior during compaction is governed by inelastic processes, as the solid material deforms, largely by shearing, to fill the voids. The resulting response depends on the strain path, e.g. isotropic versus uniaxial loading. Adjustments to the EOS are therefore fundamentally unsuited to describing porous compaction, and it is desirable to consider porous effects through the stress and strain tensors. We have investigated porous modifications to continuum strength <span class="hlt">models</span>, designed to reproduce elastic wave speeds in porous materials and the crush response observed experimentally during compaction. We have performed <span class="hlt">mesoscale</span> simulations, resolving the microstructure explicitly, to guide the construction of continuum <span class="hlt">models</span>. These simulations allow us to study the interplay between strength and EOS in the solid, the extent of dissipative flow versus non-dissipative displacement, and the evolution of porosity and micro-morphological features can be captured. This work was performed under the auspices of the U.S. Department of Energy by Lawrence Livermore National Laboratory under Contract DE-AC52-07NA27344.</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=68432041&CFTOKEN=21158963','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=68432041&CFTOKEN=21158963"><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://cfpub.epa.gov/si/si_public_record_report.cfm?dirEntryId=257882&keyword=Breeding&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=79359825&CFTOKEN=80216531','EPA-EIMS'); return false;" href="http://cfpub.epa.gov/si/si_public_record_report.cfm?dirEntryId=257882&keyword=Breeding&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=79359825&CFTOKEN=80216531"><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://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_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://adsabs.harvard.edu/abs/2008NHESS...8..445M','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2008NHESS...8..445M"><span id="translatedtitle">Introducing uncertainty of radar-rainfall estimates to the verification of <span class="hlt">mesoscale</span> <span class="hlt">model</span> precipitation forecasts</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Mittermaier, M. P.</p> <p>2008-05-01</p> <p>A simple measure of the uncertainty associated with using radar-derived rainfall estimates as "truth" has been introduced to the Numerical Weather Prediction (NWP) verification process to assess the effect on forecast skill and errors. Deterministic precipitation forecasts from the <span class="hlt">mesoscale</span> version of the UK Met Office Unified <span class="hlt">Model</span> for a two-day high-impact event and for a month were verified at the daily and six-hourly time scale using a spatially-based intensity-scale method and various traditional skill scores such as the Equitable Threat Score (ETS) and log-odds ratio. Radar-rainfall accumulations from the UK Nimrod radar-composite were used. The results show that the inclusion of uncertainty has some effect, shifting the forecast errors and skill. The study also allowed for the comparison of results from the intensity-scale method and traditional skill scores. It showed that the two methods complement each other, one detailing the scale and rainfall accumulation thresholds where the errors occur, the other showing how skillful the forecast is. It was also found that for the six-hourly forecasts the error distributions remain similar with forecast lead time but skill decreases. This highlights the difference between forecast error and forecast skill, and that they are not necessarily the same.</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%3D70%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%3D70%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://adsabs.harvard.edu/abs/2006SPIE.6404E..0LD','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2006SPIE.6404E..0LD"><span id="translatedtitle">Simulation of Nor'westers using Doppler weather radar wind observations 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>Das, Someshwar; Abhilash, S.; Das Gupta, Munmun</p> <p>2006-12-01</p> <p>Severe thunderstorms form over the Eastern and Northeastern parts of India, i.e., Gangetic West Bengal, Jharkhand, Orissa, Assam and parts of Bihar during the pre-monsoon months (April-May). These storms are known as "Nor'wester" as they move from Northwest to Southeast. In this study we have made numerical simulations of 10 thunderstorms that formed over the West Bengal region during April-May of 2005 and 2006. Numerical simulations have been carried out using MM5 <span class="hlt">mesoscale</span> <span class="hlt">model</span> (at 10 km resolution) using conventional and non-conventional observations from Doppler Weather Radar (DWR) and satellites. Composite characteristics of the Nor'wester have been made based upon the simulations. Results indicate that the Nor'westers occur generally when the CAPE increases above 1500 J Kg -1. They have updraft speeds up to 3-4 m s -1, while the downdrafts have magnitudes of about 0.4 - 0.5 m s -1. The updrafts can extend up to 8-9 km altitudes. The total amount of hydrometeors simulated inside the Nor'westers is up to 600-800 mg kg -1. Large amount of ice and snow exist at upper levels, while liquid water is present in the lower levels. The magnitudes of the ice, snow and liquid water depend on the stage of their life cycle.</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/2013JGRC..118.2476M','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2013JGRC..118.2476M"><span id="translatedtitle">Evaluation of <span class="hlt">model</span> <span class="hlt">nesting</span> performance on the Texas-Louisiana continental shelf</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Marta-Almeida, Martinho; Hetland, Robert D.; Zhang, Xiaoqian</p> <p>2013-05-01</p> <p>A skill assessment of a <span class="hlt">model</span> of the Texas-Louisiana shelf, <span class="hlt">nested</span> in a variety of different parent <span class="hlt">models</span>, is performed using hydrographic salinity data. The <span class="hlt">nested</span> <span class="hlt">models</span> show improved salinity skill compared to the same <span class="hlt">model</span> using climatological boundary conditions, as well as general skill score improvements over the parent <span class="hlt">models</span> in the same region. Although a variety of parent <span class="hlt">models</span> are used and these parent <span class="hlt">models</span> have widely different skill scores when compared with regional hydrographic data sets, the skill scores for the <span class="hlt">nested</span> <span class="hlt">models</span> are generally indistinguishable. This leads to the conclusion that <span class="hlt">nesting</span> is important for improving <span class="hlt">model</span> skill, but it does not matter which parent <span class="hlt">model</span> is used. The <span class="hlt">model</span> is also used to create a series of ensembles, where the local forcing is varied with identical boundary conditions and where the boundary conditions are varied by <span class="hlt">nesting</span> within the various parent <span class="hlt">models</span>. The variance in the ensemble spread shows that there is a significant level of unpredictable, nonlinear noise associated with instabilities along the Mississippi/Atchafalaya plume front. The noise is seasonal and is greatest during summer upwelling conditions and weaker during nonsummer downwelling.</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="https://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://adsabs.harvard.edu/abs/2013PhDT........29Y','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2013PhDT........29Y"><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://ntrs.nasa.gov/search.jsp?R=20040016359&hterms=darden&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D10%26Ntt%3Ddarden','NASA-TRS'); return false;" href="http://ntrs.nasa.gov/search.jsp?R=20040016359&hterms=darden&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D10%26Ntt%3Ddarden"><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://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=80694109&CFTOKEN=93987527','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=80694109&CFTOKEN=93987527"><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/abs/2012EGUGA..1413327S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2012EGUGA..1413327S"><span id="translatedtitle">Wave-induced boundary-layer separation: A case study comparing airborne observations and results from 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>Strauss, L.; Serafin, S.; Grubišić, V.</p> <p>2012-04-01</p> <p>Wave-induced boundary-layer separation (BLS) results from the adverse-pressure gradient forces that are exerted on the atmospheric boundary-layer by internal gravity waves in flow over orography. BLS has received significant attention in recent years, particularly so, because it is a key ingredient in the formation of atmospheric rotors. Traditionally depicted as horizontal eddies in the lee of mountain ranges, rotors originate from the interaction between internal gravity waves and the atmospheric boundary-layer. Our study focuses on the first observationally documented case of wave-induced BLS, which occurred on 26 Jan 2006 in the lee of the Medicine Bow Mountains in SE Wyoming (USA). Observations from the University of Wyoming King Air (UWKA) aircraft, in particular, the remote sensing measurements with the Wyoming Cloud Radar (WCR), reveal strong wave activity, downslope winds in excess of 30 m/s, and near-surface flow reversal in the lee of the mountain range. The fine resolution of WCR data (on the order of 40x40 m2 for two-dimensional velocity fields) exhibits fine-scale vortical structures ("subrotors") which are embedded within the main rotor zone. Our case study intends to complete the characterisation of the observed boundary-layer separation event. <span class="hlt">Modelling</span> of the event with the <span class="hlt">mesoscale</span> Weather Research and Forecast <span class="hlt">Model</span> (WRF) provides insight into the <span class="hlt">mesoscale</span> triggers of wave-induced BLS and turbulence generation. Indeed, the <span class="hlt">mesoscale</span> <span class="hlt">model</span> underpins the expected concurrence of the essential processes (gravity waves, wave breaking, downslope windstorms, etc.) leading to BLS. To exploit the recorded in situ and radar data to their full extent, a quantitative evaluation of the structure and intensity of turbulence is conducted by means of a power spectral analysis of the vertical wind component, measured along the flight track. An intercomparison of observational and <span class="hlt">modelling</span> results serves the purpose of <span class="hlt">model</span> verification and can shed some more</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.fort.usgs.gov/Products/Publications/pub_abstract.asp?PubID=3848','USGSPUBS'); return false;" href="http://www.fort.usgs.gov/Products/Publications/pub_abstract.asp?PubID=3848"><span id="translatedtitle"><span class="hlt">Modeling</span> and estimation of stage-specific daily survival probabilities of <span class="hlt">nests</span></span></a></p> <p><a target="_blank" href="http://pubs.er.usgs.gov/pubs/index.jsp?view=adv">USGS Publications Warehouse</a></p> <p>Stanley, T.R.</p> <p>2000-01-01</p> <p>In studies of avian <span class="hlt">nesting</span> success, it is often of interest to estimate stage-specific daily survival probabilities of <span class="hlt">nests</span>. When data can be partitioned by <span class="hlt">nesting</span> stage (e.g., incubation stage, nestling stage), piecewise application of the Mayfield method or Johnsona??s method is appropriate. However, when the data contain <span class="hlt">nests</span> where the transition from one stage to the next occurred during the interval between visits, piecewise approaches are inappropriate. In this paper, I present a <span class="hlt">model</span> that allows joint estimation of stage-specific daily survival probabilities even when the time of transition between stages is unknown. The <span class="hlt">model</span> allows interval lengths between visits to <span class="hlt">nests</span> to vary, and the exact time of failure of <span class="hlt">nests</span> does not need to be known. The performance of the <span class="hlt">model</span> at various sample sizes and interval lengths between visits was investigated using Monte Carlo simulations, and it was found that the <span class="hlt">model</span> performed quite well: bias was small and confidence-interval coverage was at the nominal 95% rate. A SAS program for obtaining maximum likelihood estimates of parameters, and their standard errors, is provided in the Appendix.</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://adsabs.harvard.edu/abs/2015AGUFMMR23B2665R','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015AGUFMMR23B2665R"><span id="translatedtitle"><span class="hlt">Modeling</span> plasticity of MgO at the <span class="hlt">mesoscale</span> using 2.5D Dislocation Dynamics.</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Reali, R.; Cordier, P.; Carrez, P.; Gouriet, K.; Boioli, F.</p> <p>2015-12-01</p> <p>In the lower mantle, viscosity results from the rheological behavior of the two main constituent minerals, namely (Mg,Fe,Al)SiO3bridgmanite and (Mg,Fe)O ferropericlase. Understanding how these phases deform is thus of primary importance in geophysics. This is also a very challenging task, since the extreme conditions to which the lower mantle aggregate is subjected are not reachable in laboratory experiments. In this study, the contribution of dislocations to the deformation of periclase at the <span class="hlt">mesoscale</span> is investigated by Dislocation Dynamics (DD) simulations, a <span class="hlt">modeling</span> tool which considers the collective motion and interaction of dislocations. Dislocations are expected to be one of the most efficient strain producing mechanisms. To <span class="hlt">model</span> their behavior a so-called 2.5D DD approach is employed. Within this method, dislocations are considered as straight segments perpendicular to a 2D reference plane and local rules are added to mimic 3D behavior [1]. Furthermore, both the glide and climb mechanisms can be taken into account [2]. Before simulating the deformation of MgO under P, T and strain rate conditions of the lower mantle, it is necessary to benchmark the <span class="hlt">model</span> at ambient pressure, in order to compare the simulated behavior with experiments performed in the same conditions. At high temperatures (1500-1900 K) the strain-controlling mechanism results from the interactions between dislocations. In this regime the influence of climb may be important: to investigate the competition between glide and climb mechanisms, creep simulations in pure glide conditions were performed in a wide range of temperatures and applied stresses and compared to simulations where climb is explicitly included. Power law creep parameters are evaluated and compared with experimental data. [1] D. Ǵomez-Garćıa, B. Devincre, and L. P. Kubin, Phys. Rev. Lett. 96, 125503 (2006). [2] F. Boioli, P. Carrez, P. Cordier, B. Devincre, and , M. Marquille, accepted Phys. Rev. B (2015).</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, Harry Keo</p> <p>2008-07-11</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/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://adsabs.harvard.edu/abs/2006AtmEn..40.7983A','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2006AtmEn..40.7983A"><span id="translatedtitle">Impact of two chemistry mechanisms fully coupled with <span class="hlt">mesoscale</span> <span class="hlt">model</span> on the atmospheric pollutants distribution</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Arteta, J.; Cautenet, S.; Taghavi, M.; Audiffren, N.</p> <p></p> <p> time on SGI 3800 with 30 processors). Simplified mechanisms are really important to study cases for which an online coupling is necessary between <span class="hlt">meso-scale</span> and chemistry <span class="hlt">models</span> (clouds or aerosols plumes impacts, highly variable meteorology).</p> </li> <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://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> </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/abs/2009EGUGA..1113175G','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2009EGUGA..1113175G"><span id="translatedtitle">Spatially Distributed Estimation of <span class="hlt">Mesoscale</span> Water Balance <span class="hlt">Model</span> Parameters using Hydrological Soil Maps</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Gronz, O.; Casper, M. C.; Gemmar, P.</p> <p>2009-04-01</p> <p>In <span class="hlt">mesoscale</span> water balance <span class="hlt">models</span>, the relevant hydrological processes in runoff generation are abstractly simulated. One aspect of this abstraction is grouping areas to <span class="hlt">model</span> elements, each of which simulated individually, resulting in a set of <span class="hlt">model</span> elements. A single element might be homogeneous by means of a certain characteristics, e. g. land use, but it might also be heterogeneous considering a different feature, e. g. slope. Due to this abstraction and grouping, the processes cannot be described in detail by physical laws and thus, parameters to be calibrated will occur in the <span class="hlt">model</span>'s assumptions. Typically, the same value is used for all elements of a catchment, mainly due to the quantity of all possible parameter value configurations. Thus, the spatial distribution of the occurrence of processes and their specific strength, which can be observed in the real catchment, will not be represented by the <span class="hlt">model</span>. The <span class="hlt">model</span> might rather represent the mean behavior. As a result, the distribution of water in the <span class="hlt">model</span> might not match the real system. This strongly limits the applicability of the <span class="hlt">model</span> and it increases the complexity of calibration. To support a spatial distributed parameterization of a <span class="hlt">model</span>, new sources of information need to be incorporated. One way of incorporating additional information is the usage of hydrological soil maps, which are available today. They indicate the potentially dominant runoff processes like Horton overland flow, subsurface flow, deep percolation etc. These maps are e. g. generated by artificial neural networks using various different sources like geological maps, digital terrain <span class="hlt">models</span> and characteristics derived from this <span class="hlt">model</span>, land use maps etc. An interdisciplinary project has started to integrate these maps in the calibration process. The main aim is to represent the spatial distribution shown by the map in the <span class="hlt">model</span>. An initial idea is to find parameter prototypes for each of the runoff processes. These parameter</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://eric.ed.gov/?q=CONTROL+AND+LINEAR&pg=7&id=EJ1004545','ERIC'); return false;" href="http://eric.ed.gov/?q=CONTROL+AND+LINEAR&pg=7&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://adsabs.harvard.edu/abs/2013AIPC.1558..818S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2013AIPC.1558..818S"><span id="translatedtitle">One-sided tolerance interval in a two-way balanced <span class="hlt">nested</span> <span class="hlt">model</span> with mixed effects</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Silva, A.; Carvalho, F.; Mexia, J.; Fonseca, M.</p> <p>2013-10-01</p> <p>In this paper we approach the construction of the both upper and lower tolerance limit in a two-way <span class="hlt">nested</span> <span class="hlt">model</span> with mixed effects in balanced data. In order to do so we proceed as Fonseca et al [3] did in order to derive the upper tolerance limit in a two-way <span class="hlt">nested</span> <span class="hlt">model</span> with mixed effects in unbalanced data, by using the generalized confidence interval idea earlier used by Krishnamoorthy and Mathew [4] to perform the construction of the upper tolerance limit in a one-way <span class="hlt">nested</span> <span class="hlt">model</span> with mixed or random effects <span class="hlt">model</span> in balanced and unbalanced data. The underlying idea goes through the construction of an approximation for the quantile of the general pivotal quantity for a convenient parametric function.</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://adsabs.harvard.edu/abs/2009ems..confE.589P','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2009ems..confE.589P"><span id="translatedtitle">On Demand Runs Of <span class="hlt">Mesoscale</span> <span class="hlt">Models</span> : Météo-France multi-mission, multi-support GUI</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Periard, C.; Pourret, V.; Chaupin, D.</p> <p>2009-09-01</p> <p>Numerous experiment campaigns have shown the interest of <span class="hlt">mesoscale</span> <span class="hlt">models</span> to represent weather conditions of the atmosphere as a support to various applications, from electromagnetic propagation to wind power atlas. However running <span class="hlt">mesoscale</span> <span class="hlt">models</span> requires high level knowledge on computing and <span class="hlt">modelling</span> to define the different parameters for a given simulation. With the increase of the demands for <span class="hlt">mesoscale</span> simulations, we decided to develop a GUI that enables to easily define and run type-experiments Ø at any location on the globe Ø on different types of computers (from Meteo-France Fujitsu to a PC Cluster) Ø with different choices of forcing <span class="hlt">models</span>. The GUI developed in PHP, uses a map server to visualize the location of the experiment being defined and the different forcing <span class="hlt">models</span> available for the simulation. The other parameters such as time steps, resolutions, sizes and number of embedded domains, etc … can be modified through checkboxes or multiple choices lists in the GUI. So far, the GUI has been used to run 3 different types of experiment : Ø for EM propagation purpose, during an experiment campaign near Toulon : the simulations were run on a PC Cluster in analyse mode. Ø for wind profiles prediction, in Afghanistan : the simulations are run on the Fujitsu in forecast mode. Ø for weather forecast, during a the F1 race in Japan : the simulations were run on a PC Cluster in forecast mode. During the presentation, I will first give some screen-prints of the different fill-in forms of the Gui and the way to define an experiment. Then I will focus on the 3 examples mentioned above showing different types of graphs and maps produced. There are tons of other applications where this tool is going to be useful especially in climatology: using weather type classification and downscaling, the Gui will help run the simulations of the different clusters representatives . The last thing to accomplish is find a name for the tool.</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="https://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://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://adsabs.harvard.edu/abs/2015AGUFM.A33J0321S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015AGUFM.A33J0321S"><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('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3676693','PMC'); return false;" href="https://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('https://www.ncbi.nlm.nih.gov/pubmed/23400805','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/23400805"><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="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Reese, Shawn P; Ellis, Benjamin J; Weiss, Jeffrey A</p> <p>2013-11-01</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 were 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.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016EGUGA..18.1480M','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016EGUGA..18.1480M"><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://eric.ed.gov/?q=simulation+AND+model&pg=3&id=EJ1083301','ERIC'); return false;" href="http://eric.ed.gov/?q=simulation+AND+model&pg=3&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://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/2000JChPh.113.7656H','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2000JChPh.113.7656H"><span id="translatedtitle">A <span class="hlt">mesoscale</span> strength <span class="hlt">model</span> for silica-filled polydimethylsiloxane based on atomistic forces obtained from molecular dynamics simulations</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Hanson, D. E.</p> <p>2000-11-01</p> <p>We present a novel <span class="hlt">mesoscale</span> <span class="hlt">model</span> that describes the tensile stress of silica-filled polydimethylsiloxane (PDMS) under elongation. The <span class="hlt">model</span> is based on atomistic simulations of a single chain of PDMS, interacting with itself and/or a hydroxylated silica surface. These simulations provide estimates of the microscopic forces required to stretch or uncoil a chain of PDMS, or detach it from a silica surface. For both stretching and detachment, we find that the internal potential energy is linear with the distance the chain end is moved, albeit with differing slopes. From these calculations and recent atomic force microscopy (AFM) experiments, we conclude that the forces are constant. We apply this analysis to the case of uncrosslinked, silica-filled PDMS systems and develop a <span class="hlt">mesoscale</span>, inter-particle strength <span class="hlt">model</span>. The strength <span class="hlt">model</span> includes the atomistic forces determined from the simulations, a small entropic component, and a Gaussian probability distribution to describe the distribution of chain lengths of PDMS strands connecting two silica particles and the chain lengths in the free ends. We obtain an analytic stress/strain expression whose predictions agree with experiment. This <span class="hlt">model</span> also suggests mechanisms to explain the phenomena of hysteresis and permanent set.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/26113190','PUBMED'); return false;" href="https://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="https://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.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014AGUFM.C11C0394E','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014AGUFM.C11C0394E"><span id="translatedtitle"><span class="hlt">Meso-Scale</span> Hydrological <span class="hlt">Modeling</span> Using Small Scale Parameterizations in a Discontinuous Permafrost Watershed in the 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.; Hinzman, L. D.; Morton, D.; Young, J. M.</p> <p>2014-12-01</p> <p>The sub-Arctic region lies in the transition zone between the warm temperate region to the south and the cold arctic region to the north. The sub-Arctic hosts sharply contrasting ecosystems that vary over short horizontal spatial scales due to the presence or absence of permafrost. In the discontinuous permafrost zone, the presence or absence of permafrost plays a dominant role to many hydrological processes including stream flow, soil moisture, and water storage dynamics. The distribution of permafrost also has a strong influence on ecosystem composition and function. The land cover and vegetation distribution is also an important parameter affecting the stream flow responses due to the large differences in the transpiration rates between coniferous and deciduous vegetation. As a result, accurate simulation of the hydrology in this region is challenging. The objectives of this study are to improve the parameterization of <span class="hlt">meso-scale</span> hydrologic simulations in the discontinuous permafrost zone through fine-scale observation and <span class="hlt">modeling</span>. Slope and aspect, derived from 30m Digital Elevation <span class="hlt">Model</span> (DEM), are used as a proxy for permafrost distribution and vegetation composition. Small-scale parameterizations were conducted at the two sub-basins (area ~11km2 ) of the Caribou-Poker Creeks Research Watershed (CPCRW) using the Variable Infiltration Capacity (VIC) <span class="hlt">meso-scale</span> hydrological <span class="hlt">model</span>. The small scale parameterization simulation results indicate that slope and aspect based vegetation cover and soil parameter parameterization improve <span class="hlt">meso-scale</span> hydrological <span class="hlt">modeling</span> in these regions. In order to test the extent to which these small-scale parameterizations are valid, the Chena River Basin (area ~5,478 km2), located in Interior Alaska, is being simulated using these small-scale parameterizations. Aspect will be used as the proxy for the parameterization of vegetation cover and soil property. Results from the VIC simulation using the small scale parameterization will</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/2008PhDT.......246S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2008PhDT.......246S"><span id="translatedtitle"><span class="hlt">Modeling</span> spatial patterns of wildfire susceptibility in southern California: Applications of MODIS remote sensing data and <span class="hlt">mesoscale</span> numerical weather <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>Schneider, Philipp</p> <p></p> <p>This dissertation investigates the potential of Moderate Resolution Imaging Spectroradiometer (MODIS) imagery and <span class="hlt">mesoscale</span> numerical weather <span class="hlt">models</span> for mapping wildfire susceptibility in general and for improving the Fire Potential Index (FPI) in southern California in particular. The dissertation explores the use of the Visible Atmospherically Resistant Index (VARI) from MODIS data for mapping relative greenness (RG) of vegetation and subsequently for computing the FPI. VARI-based RG was validated against in situ observations of live fuel moisture. The results indicate that VARI is superior to the previously used Normalized Difference Vegetation Index (NDVI) for computing RG. FPI computed using VARI-based RG was found to outperform the traditional FPI when validated against historical fire detections using logistic regression. The study further investigates the potential of using Multiple Endmember Spectral Mixture Analysis (MESMA) on MODIS data for estimating live and dead fractions of vegetation. MESMA fractions were compared against in situ measurements and fractions derived from data of a high-resolution, hyperspectral sensor. The results show that live and dead fractions obtained from MODIS using MESMA are well correlated with the reference data. Further, FPI computed using MESMA-based green vegetation fraction in lieu of RG was validated against historical fire occurrence data. MESMA-based FPI performs at a comparable level to the traditional NDVI-based FPI, but can do so using a single MODIS image rather than an extensive remote sensing time series as required for the RG approach. Finally this dissertation explores the potential of integrating gridded wind speed data obtained from the MM5 <span class="hlt">mesoscale</span> numerical weather <span class="hlt">model</span> in the FPI. A new fire susceptibility index, the Wind-Adjusted Fire Potential Index (WAFPI), was introduced. It modifies the FPI algorithm by integrating normalized wind speed. Validating WAFPI against historical wildfire events using</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2006AdG.....9...53K','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2006AdG.....9...53K"><span id="translatedtitle">Multiscale investigations in a <span class="hlt">mesoscale</span> catchment - hydrological <span class="hlt">modelling</span> in the Gera catchment</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Krause, P.; Bäse, F.; Bende-Michl, U.; Fink, M.; Flügel, W.; Pfennig, B.</p> <p>2006-09-01</p> <p>The application of the hydrological process-oriented <span class="hlt">model</span> J2000 (J2K) is part of a cooperation project between the Thuringian Environmental Agency (Thüringer Landesanstalt für Umwelt und Geologie - TLUG) and the Department of Geoinformatics of the Friedrich-Schiller-University Jena focussing on the implementation of the EU water framework directive (WFD). In the first project phase J2K was parametrised and calibrated for a <span class="hlt">mesoscale</span> catchment to quantify if it can be used as hydrological part of a multi-objective tool-box needed for the implementation of the WFD. The main objectives for that pilot study were: <ol> <li> The development and application of a suitable distribution concept which provide the spatial data basis for various tasks and which reflects the specific physiogeographical variability and heterogeneity of river basins adequately. This distribution concept should consider the following constraints: The absolute number of spatial entities, which forms the basis for any distributive <span class="hlt">modelling</span> should be as small as possible, but the spatial distributed factors, which controls quantitative and qualitative hydrological processes should not be generalised to much. The distribution concept of hydrological response units HRUs (Flügel, 1995) was selected and enhanced by a topological routing scheme (Staudenrausch, 2001) for the simulation of lateral flow processes. <li> J2K should be calibrated for one subbasin of the pilot watershed only. Then the parameter set should be used on the other subbasins (referred as transfer basins) to investigate and quantify the transferability of a calibrated <span class="hlt">model</span> and potential spatial dependencies of its parameter set. In addition, potential structural problems in the process description should be identified by the transfer to basins which show a different process dominance as the one which was used for calibration does. <li> <span class="hlt">Model</span> calibration and selection of efficiency criteria for the quantification of the <span class="hlt">model</span></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> </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://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('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4435188','PMC'); return false;" href="https://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('https://www.ncbi.nlm.nih.gov/pubmed/25738766','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/25738766"><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="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Steen, Kim Arild; Therkildsen, Ole Roland; Green, Ole; Karstoft, Henrik</p> <p>2015-03-02</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.</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://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/2015FlDyR..47e1401I','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015FlDyR..47e1401I"><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://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://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('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4632542','PMC'); return false;" href="https://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="https://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://cfpub.epa.gov/si/si_public_record_report.cfm?dirEntryId=266456&keyword=Breeding&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=79359825&CFTOKEN=80216531','EPA-EIMS'); return false;" href="http://cfpub.epa.gov/si/si_public_record_report.cfm?dirEntryId=266456&keyword=Breeding&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=79359825&CFTOKEN=80216531"><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://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://eric.ed.gov/?q=oconnell&pg=2&id=EJ607448','ERIC'); return false;" href="http://eric.ed.gov/?q=oconnell&pg=2&id=EJ607448"><span id="translatedtitle">Testing <span class="hlt">Nested</span> Additive, Multiplicative, and General Multitrait-Multimethod <span class="hlt">Models</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>Coenders, Germa; Saris, Willem E.</p> <p>2000-01-01</p> <p>Provides alternatives to the definitions of additive and multiplicative method effects in multitrait-multimethod data given by D. Campbell and E. O'Connell (1967). The alternative definitions can be formulated by means of constraints in the parameters of the correlated uniqueness <span class="hlt">model</span> (H. Marsh, 1989). (SLD)</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://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://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/abs/2005OptEn..44d1006W','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2005OptEn..44d1006W"><span id="translatedtitle"><span class="hlt">Mesoscale</span> distributions of ultraviolet spectral irradiance, actinic flux, and photolysis rates derived from multispectral satellite data and radiative transfer <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>Wetzel, Melanie A.; Slusser, James R.</p> <p>2005-04-01</p> <p>Global atmospheric trends in ozone column amount have focused attention on the environmental risk of exposure to ultraviolet (UV) radiation. Monitoring UV irradiance in diverse and remote locations is necessary to understand the variability of exposure, dose rates, and resultant vulnerability of ecological systems. The U.S. Department of Agriculture (USDA) UV-B Monitoring Program maintains a wide network for ground-based continuous measurement of solar radiation in several wavelengths of interest for photosynthesis, plant growth, UV exposure to humans, and photochemistry. This network provides data for analysis of UV climatology and trends at those sites. A satellite-based method to produce <span class="hlt">mesoscale</span>-resolution mapped distributions of UV spectral irradiance has been developed that utilizes this network data for verification. The methodology combines radiative transfer <span class="hlt">modeling</span>, multispectral image pixel classification, cloud optical depth retrievals, and auxiliary remote sensing data. Retrieved parameters are compared with ground-based measurements from the USDA network instrumentation at two sites [Poker Flat Research Range, Alaska; 65.12 deg N, 147.43 deg W, 550 m mean sea level (MSL); and Storm Peak Laboratory, Colorado, 40.45 deg N, 106.73 deg W, 3220 m MSL]. The results are used to evaluate the effects of cloud distribution and surface albedo in determining <span class="hlt">mesoscale</span> variability of UV exposure and photolysis rates in high-latitude and high-altitude environments.</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://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> </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.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://adsabs.harvard.edu/abs/2013EGUGA..15.5746G','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2013EGUGA..15.5746G"><span id="translatedtitle">Experimenting with a Convective Parameterization Scheme Suitable for High-Resolution <span class="hlt">Mesoscale</span> <span class="hlt">Models</span> in Tropical Cyclone Simulations</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Grell, Evelyn; Grell, Georg; Bao, Jian-Wen</p> <p>2013-04-01</p> <p>Results from numerical experiments using high-resolution <span class="hlt">mesoscale</span> <span class="hlt">models</span> have presented evidence that the use of the explicit microphysics scheme only at grid spacing from few hundred meters to a few kilometers is often not sufficient to neutralize moist instability within the grid box. A consequence of such a problem is that artificial grid-point storms may occur, which in tropical cyclone simulations can lead to erroneous representation of tropical cyclone development. The use of conventional sub-grid convection parameterization schemes to alleviate artificial grid-point storms is not appropriate in this situation since these schemes assume that the updraft area is much smaller than the <span class="hlt">model</span> grid spacing and this assumption becomes invalid when the grid size is a few kilometers or smaller. A sub-grid convection scheme suitable for high-resolution <span class="hlt">mesoscale</span> <span class="hlt">models</span> has been developed by Grell and Freitas (2013) to remove the aforementioned assumption used in conventional sub-grid convection parameterization schemes. This scheme can be used for grid spacing equal to or smaller than a few kilometers to help sufficiently remove moist instability for the entire grid point. This scheme behaves similarly to conventional schemes when the updraft area is much smaller than the grids size. As the updraft area in a grid box approaches the grid size, the parameterized sub-grid convection gradually diminishes. This presentation highlights major results from experimenting with this newly developed scheme in the Advanced Research WRF (ARW) <span class="hlt">model</span> with an idealized tropical cyclone intensification case. We will demonstrate the scheme converges (i.e., the parameterized convection diminishes as the updraft area in a grid box approaches the grid size) using the change of the intensity of parameterized sub-grid convection with the decrease in grid size. We will also discuss the issues and challenges in refining this scheme for its application in operational <span class="hlt">models</span>.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3921180','PMC'); return false;" href="https://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="https://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/abs/2014PhyA..416..518G','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014PhyA..416..518G"><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/2016ISPAr49B2..131V','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016ISPAr49B2..131V"><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://ntrs.nasa.gov/search.jsp?R=20020061382&hterms=soil+after+flooding&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D80%26Ntt%3Dsoil%2Bafter%2Bflooding','NASA-TRS'); return false;" href="http://ntrs.nasa.gov/search.jsp?R=20020061382&hterms=soil+after+flooding&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D80%26Ntt%3Dsoil%2Bafter%2Bflooding"><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=soil+after+flooding&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D80%26Ntt%3Dsoil%2Bafter%2Bflooding','NASA-TRS'); return false;" href="http://ntrs.nasa.gov/search.jsp?R=20010037685&hterms=soil+after+flooding&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D80%26Ntt%3Dsoil%2Bafter%2Bflooding"><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://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4757548','PMC'); return false;" href="http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4757548"><span id="translatedtitle">Detection of Talaromyces marneffei from Fresh Tissue of an Inhalational Murine Pulmonary <span class="hlt">Model</span> Using <span class="hlt">Nested</span> PCR</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Liu, Yinghui; Huang, Xiaowen; Yi, Xiuwen; He, Ya; Mylonakis, Eleftherios; Xi, Liyan</p> <p>2016-01-01</p> <p>Penicilliosis marneffei, often consecutive to the aspiration of Talaromyces marneffei (Penicillium marneffei), continues to be one of the significant causes of morbidity and mortality in immunocompromised patients in endemic regions such as Southeast Asia. Improving the accuracy of diagnosing this disease would aid in reducing the mortality of associated infections. In this study, we developed a stable and reproducible murine pulmonary <span class="hlt">model</span> that mimics human penicilliosis marneffei using a nebulizer to deliver Talaromyces marneffei (SUMS0152) conidia to the lungs of BALB/c nude mice housed in exposure chamber. Using this <span class="hlt">model</span>, we further revealed that <span class="hlt">nested</span> PCR was sensitive and specific for detecting Talaromyces marneffei in bronchoalveolar lavage fluid and fresh tissues. This inhalation <span class="hlt">model</span> may provide a more representative analysis tool for studying the development of penicilliosis marneffei, in addition to revealing that <span class="hlt">nested</span> PCR has a predictive value in reflecting pulmonary infection. PMID:26886887</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://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.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/cgi-bin/nph-data_query?bibcode=2011JGRD..11623114S&link_type=ABSTRACT','NASAADS'); return false;" href="http://adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2011JGRD..11623114S&link_type=ABSTRACT"><span id="translatedtitle">Confronting the WRF and RAMS <span class="hlt">mesoscale</span> <span class="hlt">models</span> with innovative observations in the Netherlands: Evaluating the boundary layer heat budget</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Steeneveld, G. J.; Tolk, L. F.; Moene, A. F.; Hartogensis, O. K.; Peters, W.; Holtslag, A. A. M.</p> <p>2011-12-01</p> <p>The Weather Research and Forecasting <span class="hlt">Model</span> (WRF) and the Regional Atmospheric <span class="hlt">Mesoscale</span> <span class="hlt">Model</span> System (RAMS) are frequently used for (regional) weather, climate and air quality studies. This paper covers an evaluation of these <span class="hlt">models</span> for a windy and calm episode against Cabauw tower observations (Netherlands), with a special focus on the representation of the physical processes in the atmospheric boundary layer (ABL). In addition, area averaged sensible heat flux observations by scintillometry are utilized which enables evaluation of grid scale <span class="hlt">model</span> fluxes and flux observations at the same horizontal scale. Also, novel ABL height observations by ceilometry and of the near surface longwave radiation divergence are utilized. It appears that WRF in its basic set-up shows satisfactory <span class="hlt">model</span> results for nearly all atmospheric near surface variables compared to field observations, while RAMS needed refining of its ABL scheme. An important inconsistency was found regarding the ABL daytime heat budget: Both <span class="hlt">model</span> versions are only able to correctly forecast the ABL thermodynamic structure when the <span class="hlt">modeled</span> surface sensible heat flux is much larger than both the eddy-covariance and scintillometer observations indicate. In order to clarify this discrepancy, <span class="hlt">model</span> results for each term of the heat budget equation is evaluated against field observations. Sensitivity studies and evaluation of radiative tendencies and entrainment reveal that possible errors in these variables cannot explain the overestimation of the sensible heat flux within the current <span class="hlt">model</span> infrastructure.</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://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/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('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4006220','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4006220"><span id="translatedtitle">Applications of a Kullback-Leibler Divergence for Comparing Non-<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>Wang, Chen-Pin; Jo, Booil</p> <p>2014-01-01</p> <p>Wang and Ghosh (2011) proposed a Kullback-Leibler divergence (KLD) which is asymptotically equivalent to the KLD by Goutis and Robert (1998) when the reference <span class="hlt">model</span> (in comparison with a competing fitted <span class="hlt">model</span>) is correctly specified and when certain regularity conditions hold true. While properties of the KLD by Wang and Ghosh (2011) have been investigated in the Bayesian framework, this paper further explores the property of this KLD in the frequentist framework using four application examples, each fitted by two competing non-<span class="hlt">nested</span> <span class="hlt">models</span>. PMID:24795532</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> </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://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://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="https://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://ntrs.nasa.gov/search.jsp?R=20020020657&hterms=process+intensification&qs=N%3D0%26Ntk%3DAll%26Ntx%3Dmode%2Bmatchall%26Ntt%3Dprocess%2Bintensification','NASA-TRS'); return false;" href="http://ntrs.nasa.gov/search.jsp?R=20020020657&hterms=process+intensification&qs=N%3D0%26Ntk%3DAll%26Ntx%3Dmode%2Bmatchall%26Ntt%3Dprocess%2Bintensification"><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/2016ACP....16.8983C','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016ACP....16.8983C"><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/abs/2016PIAHS.373..179K','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016PIAHS.373..179K"><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('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3735395','PMC'); return false;" href="https://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/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/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('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3860902','PMC'); return false;" href="https://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://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="https://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('https://www.ncbi.nlm.nih.gov/pubmed/27154874','PUBMED'); return false;" href="https://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="https://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.</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://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('https://www.ncbi.nlm.nih.gov/pubmed/19673191','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/19673191"><span id="translatedtitle">Pharmacokinetic analysis of tissue microcirculation using <span class="hlt">nested</span> <span class="hlt">models</span>: multimodel inference and parameter identifiability.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Brix, Gunnar; Zwick, Stefan; Kiessling, Fabian; Griebel, Jürgen</p> <p>2009-07-01</p> <p>The purpose of this study is to evaluate the identifiability of physiological tissue parameters by pharmacokinetic <span class="hlt">modeling</span> of concentration-time curves derived under conditions that are realistic for dynamic-contrast-enhanced (DCE) imaging and to assess the information-theoretic approach of multimodel inference using <span class="hlt">nested</span> <span class="hlt">models</span>. Tissue curves with a realistic noise level were simulated by means of an axially distributed multipath reference <span class="hlt">model</span> using typical values reported in literature on plasma flow, permeability-surface area product, and volume fractions of the intravascular and interstitial space. The simulated curves were subsequently analyzed by a two-compartment <span class="hlt">model</span> containing these physiological quantities as fit parameters as well as by two reduced <span class="hlt">models</span> with only three and two parameters formulated for the case of a permeability-limited and a flow-limited scenario, respectively. The competing <span class="hlt">models</span> were ranked according to Akaike's information criterion (AIC), balancing the bias versus variance trade-off. To utilize the information available from all three <span class="hlt">models</span>, <span class="hlt">model</span>-averaged parameters were estimated using Akaike weights that quantify the relative strength of evidence in favor of each <span class="hlt">model</span>. As compared to the full <span class="hlt">model</span>, the reduced <span class="hlt">models</span> yielded equivalent or even superior AIC values for scenarios where the structural information in the tissue curves on either the plasma flow or the capillary permeability was limited. Multimodel inference took effect to a considerable extent in half of the curves and improved the precision of the estimated tissue parameters. As theoretically expected, the plasma flow was subject to a systematic (but largely correctable) overestimation, whereas the other three physiological tissue parameters could be determined in a numerically robust and almost unbiased manner. The presented concept of pharmacokinetic analysis of noisy DCE data using three <span class="hlt">nested</span> <span class="hlt">models</span> under an information-theoretic paradigm offers</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('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4670219','PMC'); return false;" href="https://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://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://eric.ed.gov/?q=Nests&pg=3&id=EJ679891','ERIC'); return false;" href="http://eric.ed.gov/?q=Nests&pg=3&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://adsabs.harvard.edu/abs/2016EGUGA..1812793N','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016EGUGA..1812793N"><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> </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/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('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4276544','PMC'); return false;" href="https://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> <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="https://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.osti.gov/scitech/biblio/467687','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/biblio/467687"><span id="translatedtitle"><span class="hlt">Mesoscale</span> <span class="hlt">modelling</span> of the atmospheric input of nitrogen, sulphur, and lead into the German Bight for 24 April 1991</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Niemeier, U.; Schluenzen, K.H.; Bigalke, K.; Salzen, K. von</p> <p>1994-12-31</p> <p>Input of pollutants from the atmosphere into coastal seas is often neglected although it can considerably influence the concentrations of some pollutants in seawater. For example, the input of nitrogen into the North Sea is estimated to be 500 kt/a from the atmosphere and 1,100 kt/a from rivers. The input of lead into the German Bight via the atmosphere amounts to 40% of the total input. With the nonhydrostatic, three-dimensional <span class="hlt">mesoscale</span> transport and fluid <span class="hlt">model</span> METRAS, the atmospheric input into the south-east area of the North Sea (German Bight) is calculated for 24 April 1991, a day during a measurement campaign of the project PRISMA. The <span class="hlt">model</span> contains a simple chemical reaction system for nitrogen and sulphur compounds consisting of 13 reactions and 11 reactive species. Formation of sulfate and nitrate containing aerosols is described by two equilibrium gas to particle reactions. The reaction system can be used for the simulation of the nitrogen and sulphur input into the German Bight.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4214118','PMC'); return false;" href="https://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://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.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="https://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/2016IJMPB..3041002G','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016IJMPB..3041002G"><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://adsabs.harvard.edu/abs/2002AdAtS..19..487L','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2002AdAtS..19..487L"><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://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://adsabs.harvard.edu/abs/2016JOM...tmp..333A','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016JOM...tmp..333A"><span id="translatedtitle">Development of a High-Temperature Tensile Tester for Micromechanical Characterization of Materials Supporting <span class="hlt">Meso-Scale</span> ICME <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>Alam, Zafir; Eastman, David; Jo, Minjea; Hemker, Kevin</p> <p>2016-09-01</p> <p>A high-temperature tensile tester (HTTT) has been established for the evaluation of micro-mechanical properties of materials at the <span class="hlt">meso-scale</span>. Metals and ceramics can now be tested at temperatures and strain rates between room temperature and 1200°C and 10-5 s-1 to 10-1 s-1, respectively. The samples are heated in a compact clam shell furnace and strain is measured directly in the sample gage with digital image correlation. The HTTT extracts representative mechanical properties, as evidenced by the similarity in the evaluated micro-tensile properties of a solid solution-strengthened Ni-base superalloy Ni-625 with that of the bulk. The effectiveness of the HTTT has also been demonstrated in evaluating the tensile and stress relaxation/short-term creep properties of a polycrystalline Ni-base superalloy René 88DT. The versatility in carrying out tensile, short-term creep, bend tests, and fracture toughness measurements makes the HTTT a robust experimental tool for small-scale and scale-specific benchmarking of multi-scale ICME <span class="hlt">models</span>.</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/2016APS..MARX19009T','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016APS..MARX19009T"><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> <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://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="https://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://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/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/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=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> </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://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=Genesis&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D20%26Ntt%3DGenesis','NASA-TRS'); return false;" href="http://ntrs.nasa.gov/search.jsp?R=20120013630&hterms=Genesis&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D20%26Ntt%3DGenesis"><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">mesoscale</span> numerical weather prediction (NWP) <span class="hlt">model</span>: eight years of experience</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Kaufmann, P.; Schubiger, F.; Binder, P.</p> <p></p> <p>The Swiss <span class="hlt">Model</span>, a hydrostatic numerical weather prediction <span class="hlt">model</span>, has been used at MeteoSwiss for operational forecasting at the meso-beta scale (mesh-size 14 km) from 1994 until 2001. The quality of the quantitative precipitation forecasts is evaluated for the eight years of operation. The seasonal precipitation over Switzerland and its dependence on altitude is examined for both <span class="hlt">model</span> forecasts and observations using the Swiss rain gauge network sampling daily precipitation at over 400 stations for verification. The mean diurnal cycle of precipitation is verified against the automatic surface observation network on the basis of hourly recordings. In winter, there is no diurnal forcing of precipitation and the <span class="hlt">modelled</span> precipitation agrees with the observed values. In summer, the convection in the <span class="hlt">model</span> starts too early, overestimates the amount of precipitation and is too short-lived. Skill scores calculated for six-hourly precipitation sums show a constant level of performance over the <span class="hlt">model</span> life cycle. Dry and wet seasons influence the <span class="hlt">model</span> performance more than the <span class="hlt">model</span> changes during its operational period. The comprehensive verification of the <span class="hlt">model</span> precipitation is complemented by the discussion of a number of heavy rain events investigated during the RAPHAEL project. The sensitivities to a number of <span class="hlt">model</span> components are illustrated, namely the driving boundary fields, the internal partitioning of parameterised and grid-scale precipitation, the advection scheme and the vertical resolution. While a small impact of the advection scheme had to be expected, the increasing overprediction of rain with increasing vertical resolution in the RAPHAEL case studies was larger than previously thought. The frequent update of the boundary conditions enhances the positioning of the rain in the <span class="hlt">model</span>.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/20040034130','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20040034130"><span id="translatedtitle">A Stochastic <span class="hlt">Model</span> of Space-Time Variability of <span class="hlt">Mesoscale</span> Rainfall: Statistics of Spatial Averages</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Kundu, Prasun K.; Bell, Thomas L.</p> <p>2003-01-01</p> <p>A characteristic feature of rainfall statistics is that they depend on the space and time scales over which rain data are averaged. A previously developed spectral <span class="hlt">model</span> of rain statistics that is designed to capture this property, predicts power law scaling behavior for the second moment statistics of area-averaged rain rate on the averaging length scale L as L right arrow 0. In the present work a more efficient method of estimating the <span class="hlt">model</span> parameters is presented, and used to fit the <span class="hlt">model</span> to the statistics of area-averaged rain rate derived from gridded radar precipitation data from TOGA COARE. Statistical properties of the data and the <span class="hlt">model</span> predictions are compared over a wide range of averaging scales. An extension of the spectral <span class="hlt">model</span> scaling relations to describe the dependence of the average fraction of grid boxes within an area containing nonzero rain (the "rainy area fraction") on the grid scale L is also explored.</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://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/2015EGUGA..17.7162M','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015EGUGA..17.7162M"><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> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/20040171259','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20040171259"><span id="translatedtitle">High-Resolution <span class="hlt">Mesoscale</span> Simulations of the 6-7 May 2000 Missouri Flash Flood: Impact of <span class="hlt">Model</span> Initialization and Land Surface Treatment</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Baker, R. David; Wang, Yansen; Tao, Wei-Kuo; Wetzel, Peter; Belcher, Larry R.</p> <p>2004-01-01</p> <p>High-resolution <span class="hlt">mesoscale</span> <span class="hlt">model</span> simulations of the 6-7 May 2000 Missouri flash flood event were performed to test the impact of <span class="hlt">model</span> initialization and land surface treatment on timing, intensity, and location of extreme precipitation. In this flash flood event, a <span class="hlt">mesoscale</span> convective system (MCS) produced over 340 mm of rain in roughly 9 hours in some locations. Two different types of <span class="hlt">model</span> initialization were employed: 1) NCEP global reanalysis with 2.5-degree grid spacing and 12-hour temporal resolution, and 2) Eta reanalysis with 40- km grid spacing and $hour temporal resolution. In addition, two different land surface treatments were considered. A simple land scheme. (SLAB) keeps soil moisture fixed at initial values throughout the simulation, while a more sophisticated land <span class="hlt">model</span> (PLACE) allows for r interactive feedback. Simulations with high-resolution Eta <span class="hlt">model</span> initialization show considerable improvement in the intensity of precipitation due to the presence in the initialization of a residual <span class="hlt">mesoscale</span> convective vortex (hlCV) from a previous MCS. Simulations with the PLACE land <span class="hlt">model</span> show improved location of heavy precipitation. Since soil moisture can vary over time in the PLACE <span class="hlt">model</span>, surface energy fluxes exhibit strong spatial gradients. These surface energy flux gradients help produce a strong low-level jet (LLJ) in the correct location. The LLJ then interacts with the cold outflow boundary of the MCS to produce new convective cells. The simulation with both high-resolution <span class="hlt">model</span> initialization and time-varying soil moisture test reproduces the intensity and location of observed rainfall.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/biblio/1275360-interactive-mesoscale-lagrangian-puff-dispersion-model-deposition-decay-see-ccc-mesorad','SCIGOV-ESTSC'); return false;" href="http://www.osti.gov/scitech/biblio/1275360-interactive-mesoscale-lagrangian-puff-dispersion-model-deposition-decay-see-ccc-mesorad"><span id="translatedtitle">Interactive <span class="hlt">Mesoscale</span> Lagrangian Puff Dispersion <span class="hlt">Model</span> with Deposition and Decay. See CCC-677/MESORAD.</span></a></p> <p><a target="_blank" href=""></a></p> <p></p> <p>1986-06-15</p> <p>Version: 00 MESOI Version 2.0 is a third generation Lagrangian puff transport and diffusion <span class="hlt">model</span> based on the earlier MESODIF <span class="hlt">model</span>. It explicitly treats physical processes affecting material released to the atmosphere which were not treated in the earlier versions. It is an interactive <span class="hlt">model</span> for estimating the transport, diffusion, deposition and decay of effluents released to the atmosphere. It is capable of treating simultaneous releases from as many as four release points which maymore » be elevated or at ground level.« less</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/servlets/purl/1211581','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/servlets/purl/1211581"><span id="translatedtitle"><span class="hlt">Modeling</span> Hot-Spot Contributions in Shocked High Explosives at the <span class="hlt">Mesoscale</span></span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Harrier, Danielle</p> <p>2015-08-12</p> <p>When looking at performance of high explosives, the defects within the explosive become very important. Plastic bonded explosives, or PBXs, contain voids of air and bonder between the particles of explosive material that aid in the ignition of the explosive. These voids collapse in high pressure shock conditions, which leads to the formation of hot spots. Hot spots are localized high temperature and high pressure regions that cause significant changes in the way the explosive material detonates. Previously hot spots have been overlooked with <span class="hlt">modeling</span>, but now scientists are realizing their importance and new <span class="hlt">modeling</span> systems that can accurately <span class="hlt">model</span> hot spots are underway.</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.; 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://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://adsabs.harvard.edu/abs/2006WiEn....9..109B','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2006WiEn....9..109B"><span id="translatedtitle">A study of valley winds using the MIUU <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>Bergström, Hans; Juuso, Nikolaus</p> <p>2006-01-01</p> <p>High winds are sometimes found in low-altitude terrain in mountain valleys. The reasons for this and the possibilities to find such sites from <span class="hlt">modelled</span> wind fields are investigated. The higher-order closure MIUU <span class="hlt">model</span> developed at Uppsala University is used for a general study of channelling of winds in mountain valleys. The importance of length, width and depth of the valley is investigated. Comparisons are made with wind measurements. Copyright</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016ACP....1612099J','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016ACP....1612099J"><span id="translatedtitle"><span class="hlt">Modeling</span> the reactive halogen plume from Ambrym and its impact on the troposphere with the CCATT-BRAMS <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>Jourdain, Line; Roberts, Tjarda Jane; Pirre, Michel; Josse, Beatrice</p> <p>2016-09-01</p> <p>Ambrym Volcano (Vanuatu, southwest Pacific) is one of the largest sources of continuous volcanic emissions worldwide. As well as releasing SO2 that is oxidized to sulfate, volcanic plumes in the troposphere are shown to undergo reactive halogen chemistry whose atmospheric impacts have been little explored to date. Here, we investigate with the regional-scale <span class="hlt">model</span> CCATT-BRAMS (Coupled Chemistry Aerosol-Tracer Transport <span class="hlt">model</span>, Brazilian developments on the Regional Atmospheric <span class="hlt">Modeling</span> System, version 4.3) the chemical processing in the Ambrym plume and the impact of this volcano on the atmospheric chemistry on both local and regional scales. We focus on an episode of extreme passive degassing that occurred in early 2005 and for which airborne DOAS (differential optical absorption spectroscopy) measurements of SO2 and BrO columns in the near-downwind plume between 15 and 40 km from the vents have been reported. The <span class="hlt">model</span> was developed to include reactive halogen chemistry and a volcanic emission source specific to this extreme degassing event. In order to test our understanding of the volcanic plume chemistry, we performed very high-resolution (500 m × 500 m) simulations using the <span class="hlt">model</span> <span class="hlt">nesting</span> grid capability and compared each DOAS measurement to its temporally and spatially interpolated <span class="hlt">model</span> counterpart "point-by-point". Simulated SO2 columns show very good quantitative agreement with the DOAS observations, suggesting that the plume direction as well as its dilution in the near-downwind plume are well captured. The <span class="hlt">model</span> also reproduces the salient features of volcanic chemistry as reported in previous work, such as HOx and ozone depletion in the core of the plume. When a high-temperature chemistry initialization is included, the <span class="hlt">model</span> is able to capture the observed BrO / SO2 trend with distance from the vent. The main discrepancy between observations and <span class="hlt">model</span> is the bias between the magnitudes of observed and simulated BrO columns that ranges from 60</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2013AtmRe.124....1H','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2013AtmRe.124....1H"><span id="translatedtitle">A <span class="hlt">mesoscale</span> simulation of coastal circulation in the Guadalquivir valley (southwestern Iberian Peninsula) using the WRF-ARW <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>Hernández-Ceballos, M. A.; Adame, J. A.; Bolívar, J. P.; De la Morena, B. A.</p> <p>2013-04-01</p> <p>Located in the southwest of the Iberian Peninsula, the Guadalquivir valley is a site of frequent problems related to air pollution. The atmospheric dynamics of this region is poorly characterised but is fundamental to understanding the chemical and photochemical processes that contribute to the pollution problems. In this work, the atmospheric <span class="hlt">mesoscale</span> Weather Research and Forecasting (WRF-ARW) <span class="hlt">model</span> was used to study the horizontal and vertical development of the two sea-land breeze patterns (pure and non-pure) that are identified in the coastal area as being responsible for many of the air pollution events. In addition, data from five meteorological stations within the valley were used to validate and compare the <span class="hlt">model</span> results. The FNL archives were used to define the initial and boundary conditions of the <span class="hlt">model</span>. Four domains with a grid resolution of 81, 27, 9 and 3 km and 40 sigma pressure levels in each domain were defined. The Medium Range and Forecast (MRF) parameterisation scheme was used with new values for both the bulk critical Richardson number and the coefficient of proportionality. This new configuration was obtained from the sensitivity exercises. Several periods were <span class="hlt">modelled</span> for both breeze patterns, focusing on the wind, the potential temperatures and the specific humidity fields. For the pure breeze, the horizontal movement along the valley was conditioned by the arrival of a Mediterranean flow in the Guadalquivir valley that limits the horizontal extension of the breeze to 20-40 km inland. In contrast, the non-pure pattern was only identified in the coastal area; although motivated by the entrance of southwestern flows, a marine air mass transport along the valley was detected and reached inland areas located approximately 200 km from the coast line. In both cases, the <span class="hlt">model</span> results indicated the formation of a thermal internal boundary layer with a vertical development of less than 500 m for the pure sea breeze while for the non-pure breeze</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/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/2002EGSGA..27.4204L','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2002EGSGA..27.4204L"><span id="translatedtitle">Network-based <span class="hlt">Modeling</span> of <span class="hlt">Mesoscale</span> Catchments - The Hydrology Perspective of Glowa-danube</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Ludwig, R.; Escher-Vetter, H.; Hennicker, R.; Mauser, W.; Niemeyer, S.; Reichstein, M.; Tenhunen, J.</p> <p></p> <p>Within the GLOWA initiative of the German Ministry for Research and Educa- tion (BMBF), the project GLOWA-Danube is funded to establish a transdisciplinary network-based decision support tool for water related issues in the Upper Danube wa- tershed. It aims to develop and validate integration techniques, integrated <span class="hlt">models</span> and integrated monitoring procedures and to implement them in the network-based De- cision Support System DANUBIA. An accurate description of processes involved in energy, water and matter fluxes and turnovers requires an intense collaboration and exchange of water related expertise of different scientific disciplines. DANUBIA is conceived as a distributed expert network and is developed on the basis of re-useable, refineable, and documented sub-<span class="hlt">models</span>. In order to synthesize a common understand- ing between the project partners, a standardized notation of parameters and functions and a platform-independent structure of computational methods and interfaces has been established using the Unified <span class="hlt">Modeling</span> Language UML. DANUBIA is object- oriented, spatially distributed and raster-based at its core. It applies the concept of "proxels" (Process Pixel) as its basic object, which has different dimensions depend- ing on the viewing scale and connects to its environment through fluxes. The presented study excerpts the hydrological view point of GLOWA-Danube, its approach of <span class="hlt">model</span> coupling and network based communication (using the Remote Method Invocation RMI), the object-oriented technology to simulate physical processes and interactions at the land surface and the methodology to treat the issue of spatial and temporal scal- ing in large, heterogeneous catchments. The mechanisms applied to communicate data and <span class="hlt">model</span> parameters across the typical discipline borders will be demonstrated from the perspective of a land-surface object, which comprises the capabilities of interde- pendent expert <span class="hlt">models</span> for snowmelt, soil water movement, runoff formation, plant</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2012PhDT.......233L','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2012PhDT.......233L"><span id="translatedtitle"><span class="hlt">Mesoscale</span> <span class="hlt">modeling</span> of strain induced solid state amorphization in crystalline materials</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Lei, Lei</p> <p></p> <p>Solid state amorphization, and in particular crystalline to amorphous transformation, can be observed in metallic alloys, semiconductors, intermetallics, minerals, and also molecular crystals when they undergo irradiation, hydrogen gas dissolution, thermal interdiffusion, mechanical alloying, or mechanical milling. Although the amorphization mechanisms may be different, the transformation occurs due to the high level of disorder introduced into the material. Milling induced solid state amorphization is proposed to be the result of accumulation of crystal defects, specifically dislocations, as the material is subjected to large deformations during the high energy process. Thus, understanding the deformation mechanisms of crystalline materials will be the first step in studying solid state amorphization in crystalline materials, which not only has scientific contributions, but also technical consequences. A phase field dislocation dynamics (PFDD) approach is employed in this work to simulate plastic deformation of molecular crystals. This PFDD <span class="hlt">model</span> has the advantage of tracking all of the dislocations in a material simultaneously. The <span class="hlt">model</span> takes into account the elastic interaction between dislocations, the lattice resistance to dislocation motion, and the elastic interaction of dislocations with an external stress field. The PFDD <span class="hlt">model</span> is employed to describe the deformation of molecular crystals with pharmaceutical applications, namely, single crystal sucrose, acetaminophen, gamma-indomethacin, and aspirin. Stress-strain curves are produced that result in expected anisotropic material response due to the activation of different slip systems and yield stresses that agree well with those from experiments. The PFDD <span class="hlt">model</span> is coupled to a phase transformation <span class="hlt">model</span> to study the relation between plastic deformation and the solid state amorphization of crystals that undergo milling. This <span class="hlt">model</span> predicts the amorphous volume fraction in excellent agreement with</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2012AtmEn..54..168G','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2012AtmEn..54..168G"><span id="translatedtitle">Impact of HONO sources on the performance of <span class="hlt">mesoscale</span> air quality <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>Gonçalves, M.; Dabdub, D.; Chang, W. L.; Jorba, O.; Baldasano, J. M.</p> <p>2012-07-01</p> <p>Nitrous acid (HONO) photolysis constitutes a primary source of OH in the early morning, which leads to changes in <span class="hlt">model</span> gas-phase and particulate matter concentrations. However, state-of-the-art <span class="hlt">models</span> of chemical mechanisms share a common representation of gas-phase chemistry leading to HONO that fails in reproducing the observed profiles. Hence, there is a growing interest in improving the definition of additional HONO sources within air quality <span class="hlt">models</span>, i.e. direct emissions or heterogeneous reactions. In order to test their feasibility under atmospheric conditions, the WRF-ARW/HERMES/CMAQ <span class="hlt">modeling</span> system is applied with high horizontal resolution (4 × 4 km2) to Spain for November 24-27, 2008. HONO <span class="hlt">modeled</span> sources include: (1) direct emissions from on-road transport; NO2 hydrolysis on aerosol and ground surfaces, the latter with (2) kinetics depending exclusively on available surfaces for reaction and (3) refined kinetics considering also relative humidity dependence; and (4) photoenhanced NO2 reduction on ground surfaces. The DOMINO measurement campaign performed in El Arenosillo (Southern Spain) provides valuable HONO observations. <span class="hlt">Modeled</span> HONO results are consistently below observations, even when the most effective scenario is assessed, corresponding to contributions of direct emissions and NO2 hydrolysis with the simplest kinetics parameterization. With the additional sources of HONO, PM2.5 predictions can be up to 14% larger in urban areas. Quantified impacts on secondary pollutants have to be taken as a low threshold, due to the proven underestimation of HONO levels. It is fundamental to improve HONO sources definition within air quality <span class="hlt">models</span>, both for the scientific community and decision makers.</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://ntrs.nasa.gov/search.jsp?R=20070016641&hterms=Hurricane+Katrina&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D20%26Ntt%3D%2528Hurricane%2BKatrina%2529','NASA-TRS'); return false;" href="http://ntrs.nasa.gov/search.jsp?R=20070016641&hterms=Hurricane+Katrina&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D20%26Ntt%3D%2528Hurricane%2BKatrina%2529"><span id="translatedtitle">Hurricane Intensity Forecasts with a Global <span class="hlt">Mesoscale</span> <span class="hlt">Model</span> on the NASA Columbia Supercomputer</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; Atlas, Robert</p> <p>2006-01-01</p> <p>It is known that General Circulation <span class="hlt">Models</span> (GCMs) have insufficient resolution to accurately simulate hurricane near-eye structure and intensity. The increasing capabilities of high-end computers (e.g., the NASA Columbia Supercomputer) have changed this. In 2004, the finite-volume General Circulation <span class="hlt">Model</span> at a 1/4 degree resolution, doubling the resolution used by most of operational NWP center at that time, was implemented and run to obtain promising landfall predictions for major hurricanes (e.g., Charley, Frances, Ivan, and Jeanne). In 2005, we have successfully implemented the 1/8 degree version, and demonstrated its performance on intensity forecasts with hurricane Katrina (2005). It is found that the 1/8 degree <span class="hlt">model</span> is capable of simulating the radius of maximum wind and near-eye wind structure, and thereby promising intensity forecasts. In this study, we will further evaluate the <span class="hlt">model</span> s performance on intensity forecasts of hurricanes Ivan, Jeanne, Karl in 2004. Suggestions for further <span class="hlt">model</span> development will be made in the end.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/servlets/purl/5591130','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/servlets/purl/5591130"><span id="translatedtitle">MESOI Version 2. 0: an interactive <span class="hlt">mesoscale</span> Lagrangian puff dispersion <span class="hlt">model</span> with deposition and decay</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Ramsdell, J.V.; Athey, G.F.; Glantz, C.S.</p> <p>1983-11-01</p> <p>MESOI Version 2.0 is an interactive Lagrangian puff <span class="hlt">model</span> for estimating the transport, diffusion, deposition and decay of effluents released to the atmosphere. The <span class="hlt">model</span> is capable of treating simultaneous releases from as many as four release points, which may be elevated or at ground-level. The puffs are advected by a horizontal wind field that is defined in three dimensions. The wind field may be adjusted for expected topographic effects. The concentration distribution within the puffs is initially assumed to be Gaussian in the horizontal and vertical. However, the vertical concentration distribution is modified by assuming reflection at the ground and the top of the atmospheric mixing layer. Material is deposited on the surface using a source depletion, dry deposition <span class="hlt">model</span> and a washout coefficient <span class="hlt">model</span>. The <span class="hlt">model</span> also treats the decay of a primary effluent species and the ingrowth and decay of a single daughter species using a first order decay process. This report is divided into two parts. The first part discusses the theoretical and mathematical bases upon which MESOI Version 2.0 is based. The second part contains the MESOI computer code. The programs were written in the ANSI standard FORTRAN 77 and were developed on a VAX 11/780 computer. 43 references, 14 figures, 13 tables.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://ntrs.nasa.gov/search.jsp?R=19990072355&hterms=solar+energy+impacts&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D70%26Ntt%3Dsolar%2Benergy%2Bimpacts','NASA-TRS'); return false;" href="http://ntrs.nasa.gov/search.jsp?R=19990072355&hterms=solar+energy+impacts&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D70%26Ntt%3Dsolar%2Benergy%2Bimpacts"><span id="translatedtitle">Real-Time Assimilation of Goes-Derived Products into A <span class="hlt">Mesoscale</span> <span class="hlt">Model</span> and It's Impact on Short-Term (06-36hr) Forecasts from 17 October 1998 through the Present</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; Jedlovec, Gary; McNider, Richard T.</p> <p>1999-01-01</p> <p>As the parameterizations of surface energy budgets in regional <span class="hlt">models</span> have become more complete physically, <span class="hlt">models</span> have the potential to be much more realistic in simulations of coupling between surface radiation, hydrology, and surface energy transfer. Realizing the importance of properly specifying the surface energy budget, many institutions are using land-surface <span class="hlt">models</span> to represent the lower boundary forcing associated with biophysical processes and soil hydrology. However, the added degrees of freedom due to inclusion of such land-surface schemes require the specification of additional parameters within the <span class="hlt">model</span> system such as vegetative resistances, green vegetation fraction, leaf area index, soil physical and hydraulic characteristics, stream flow, runoff, and the vertical distribution of soil moisture. Spatial heterogeneity of these parameters makes correct specification problematic since measurements are not routinely available. A technique has been developed for assimilating GOES-IR skin temperature tendencies, solar insolation, and surface albedo 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. The technique has been successfully employed in a number of <span class="hlt">mesoscale</span> <span class="hlt">models</span> in case-study mode. We have taken the next step and developed a study to determine if assimilating these types of data into <span class="hlt">mesoscale</span> <span class="hlt">models</span> in real-time can improve short-term (648h) forecasts of temperature, relative humidity, and QPF on a daily basis over relatively large regions. Therefore, an operational <span class="hlt">modeling</span>/assimilation system has been developed at the GHCC during the past summer that allows us to produce simulations out to 48 hours in a timely manor. The PSU/NCAR MM5 is used in a <span class="hlt">nested</span> configuration with a 25 km grid covering the southeastern third of the US. The <span class="hlt">model</span> has been on-line since 1 July 1998 and forecast products are posted on our web site. The satellite</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/biblio/28711','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/biblio/28711"><span id="translatedtitle">Random variability in <span class="hlt">mesoscale</span> wind observations and implications for diffusion <span class="hlt">models</span></span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Hanna, S.R.</p> <p>1994-12-31</p> <p>The investigation reported in this paper grew out of a preliminary analysis of methods by which regional air quality <span class="hlt">models</span> such as the Regional Oxidant <span class="hlt">Model</span> account for horizontal transport and diffusion. It was discovered that there is a variety of often inconsistent methods used to parameterize horizontal diffusion at meso- and regional scales, and the time seemed ripe to review and compare and contrast these schemes. This paper provides a brief overview of the major issues that were uncovered and lists a few specific examples of the technical approaches that are used. Subsequent sections cover the basic physics of horizontal diffusion, the characteristics of observed wind fields, and methods of parameterizing horizontal diffusion in air quality <span class="hlt">models</span>.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2009APS..MARQ13005B','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2009APS..MARQ13005B"><span id="translatedtitle">Coupling of Atomistic and <span class="hlt">Meso-scale</span> Phase-field <span class="hlt">Modeling</span> of Rapid Solidification</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Belak, J.; Turchi, P. E. A.; Dorr, M. R.; Richards, D. F.; Fattebert, J.-L.; Wickett, M. E.; Streitz, F. H.</p> <p>2009-03-01</p> <p>Recently, phase field <span class="hlt">models</span> have been introduced to <span class="hlt">model</span> the crystallography during polycrystal microstructure evolution [1,2]. Here, we assess these <span class="hlt">models</span> with molecular dynamics and phase field simulations that overlap in time and space. Large parallel computers have enabled MD simulations of sufficient scale to observe the formation of realistic microstructure during pressure driven solidification [3]. We compare the two methods by calculating the phase field order parameter (quaternion) from the atomic coordinates and drive the evolution with the MD. Results will be presented for the solidification of tantalum. [1] R. Kobayashi and J.A. Warren, Physica A, 356, 127-132 (2005). [2] T. Pusztai, G. Bortel and L. Granasy, Europhys. Lett, 71, 131-137 (2005). [3] F. H. Streitz, J. N. Glosli, and M. V. Patel, Phys. Rev. Lett. 96, 225701 (2006).</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2009APS..SHK.L5006B','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2009APS..SHK.L5006B"><span id="translatedtitle">Coupling of Atomistic and <span class="hlt">Meso-scale</span> Phase-field <span class="hlt">Modeling</span> of Rapid Solidification</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Belak, J.; Turchi, P. E. A.; Dorr, M. R.; Richards, D. F.; Fattebert, J.-L.; Wickett, M. E.; Streitz, F. H.; Tang, M.; Moelans, N.</p> <p>2009-06-01</p> <p>Recently, phase-field <span class="hlt">models</span> have been introduced to <span class="hlt">model</span> the crystallography during polycrystal microstructure evolution [1,2]. Here, we assess these <span class="hlt">models</span> with molecular dynamics and phase-field simulations that overlap in time and space. Large parallel computers have enabled MD simulations of sufficient scale to observe the formation of realistic microstructure during pressure driven solidification [3]. We compare the two methods by calculating the phase field order parameter (quaternion) from the atomic coordinates and drive the evolution with the MD. Results will be presented for the solidification of tantalum. [1] R. Kobayashi and J.A. Warren, Physica A, 356, 127-132 (2005). [2] T. Pusztai, G. Bortel and L. Granasy, Europhys. Lett, 71, 131-137 (2005). [3] F. H. Streitz, J. N. Glosli, and M. V. Patel, Phys. Rev. Lett. 96, 225701 (2006).</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2003ASAJ..114.2429F','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2003ASAJ..114.2429F"><span id="translatedtitle">A sub-<span class="hlt">mesoscale</span> hydrodynamic/acoustic simulation <span class="hlt">model</span> for continental shelf-break regions</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Finette, Steven; Shen, Colin Y.; Evans, Thomas E.</p> <p>2003-10-01</p> <p>A nonhydrostatic, hydrodynamic <span class="hlt">model</span> of the sound speed field in a continental shelf-break environment has been developed and implemented. The <span class="hlt">model</span> is based on a vorticity formulation of the equations of motion for an incompressible fluid with a free ocean surface, and it is capable of simulating the generation and propagation of internal tides and solibores under tidal forcing. The <span class="hlt">model</span> has been benchmarked with an exact numerical solution for a soliton. A set of space and time evolving sound speed distributions is integrated with a parabolic equation code to compute time and frequency dependent pressure fields. Two-dimensional examples of broad-band signal gain degradation on vertical arrays in this environment are presented, as well as range-frequency maps that illustrate the structure of the waveguide invariant in a shelf-break environment that is changing in time. Implications for source localization are considered. [Work supported by ONR.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016ApPhA.122..890C','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016ApPhA.122..890C"><span id="translatedtitle"><span class="hlt">Mesoscale</span> <span class="hlt">modeling</span> and simulation of microstructure evolution during dynamic recrystallization of a Ni-based superalloy</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Chen, Fei; Cui, Zhenshan; Ou, Hengan; Long, Hui</p> <p>2016-10-01</p> <p>Microstructural evolution and plastic flow characteristics of a Ni-based superalloy were investigated using a simulative <span class="hlt">model</span> that couples the basic metallurgical principle of dynamic recrystallization (DRX) with the two-dimensional (2D) cellular automaton (CA). Variation of dislocation density with local strain of deformation is considered for accurate determination of the microstructural evolution during DRX. The grain topography, the grain size and the recrystallized fraction can be well predicted by using the developed CA <span class="hlt">model</span>, which enables to the establishment of the relationship between the flow stress, dislocation density, recrystallized fraction volume, recrystallized grain size and the thermomechanical parameters.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2012AGUFM.B51B0508U','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2012AGUFM.B51B0508U"><span id="translatedtitle">Inclusion of CO2 fluxes in a coupled <span class="hlt">mesoscale</span> land surface and 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>Uebel, M.; Shrestha, P.; Sulis, M.; Bott, A.</p> <p>2012-12-01</p> <p>An essential part of numerical weather prediction <span class="hlt">models</span> is the accurate simulation of the interaction of the land surface with the lower atmosphere. Thus, a detailed knowledge of the land surface characteristics is an inevitable precondition for a successful numerical weather forecast. Here, we present a fully coupled atmospheric <span class="hlt">model</span> system that comprehensively simulates the exchange processes between the soil, the vegetation and the atmosphere in terms of water, carbon dioxide (CO2), heat and momentum fluxes. The <span class="hlt">model</span> system couples the Community Land <span class="hlt">Model</span> (CLM) to the non-hydrostatic weather prediction <span class="hlt">model</span> COSMO of the German Meteorological Service. Field measurements on the regional scale indicate distinct spatio-temporal heterogeneities of atmospheric CO2 concentrations. This variable atmospheric CO2 partial pressure induces a direct response of the stomatal resistance of the plants resulting in a modified plant transpiration. This effect has a noticeable influence on the moisture and heat fluxes at the land surface which in turn may have a strong impact on the time evolution of the atmospheric planetary boundary layer (PBL). Since the evapotranspiration of plants is strongly controlled by the atmospheric humidity and CO2 concentration, for a consistent <span class="hlt">modeling</span> of latent and sensible heat fluxes at the land surface a detailed treatment of the exchange of CO2 between the canopy and the PBL is of particular importance. To account for these effects, as a first step we implemented CO2 in the COSMO <span class="hlt">model</span> as a passive tracer so that the spatial and temporal variations of the atmospheric CO2 concentration as caused by advective, turbulent and convective processes can now be simulated with reasonable accuracy. In the offline version of CLM photosynthesis and plant transpiration are calculated by utilizing a constant value of the atmospheric CO2 partial pressure. In contrast to this treatment, the coupled <span class="hlt">model</span> system COSMO-CLM considers the varying atmospheric</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2012AIPC.1426..705S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2012AIPC.1426..705S"><span id="translatedtitle"><span class="hlt">Mesoscale</span> <span class="hlt">modeling</span> of deflagration-induced deconsolidation in polymer-bonded explosives</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; Glascoe, Elizabeth A.; Reaugh, John E.; Kercher, James; Maienschein, Jon L.</p> <p>2012-03-01</p> <p>Initially undamaged polymer-bonded explosives can transition from conductive burning to more violent convective burning via rapid deconsolidation at higher pressures. The pressure-dependent infiltration of cracks and pores, i.e., damage, by product gases at the burn-front is a key step in the transition to convective burning. However, the relative influence of pre-existing damage and the evolution of deflagration-induced damage during the transition to convective burning is not well understood. The objective of this study is to investigate the role of microstructure and initial pressurization on deconsolidation. We performed simulations using the multi-physics hydrocode, ALE3D. HMX-Viton A served as our <span class="hlt">model</span> explosive. A Prout-Tompkins chemical kinetic <span class="hlt">model</span>, Vielle's Law pressure-dependent burning, Gruneisen equation-of-state, and simplified strength <span class="hlt">model</span> were used for the HMX. The propensity for deconsolidation increased with increasing defect size and decreasing initial pressurization, as measured by the increase in burning surface area. These studies are important because they enable the development of continuum-scale damage <span class="hlt">models</span> and the design of inherently safer explosives.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/servlets/purl/1022908','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/servlets/purl/1022908"><span id="translatedtitle"><span class="hlt">MESOSCALE</span> <span class="hlt">MODELING</span> OF DEFLAGRATION-INDUCED DECONSOLIDATION IN POLYMER-BONDED EXPLOSIVES</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Springer, H K; Glascoe, E A; Reaugh, J E; Kercher, J R; Maienschein, J L</p> <p>2011-08-01</p> <p>Initially undamaged polymer-bonded explosives can transition from conductive burning to more violent convective burning via rapid deconsolidation at higher pressures. The pressure-dependent infiltration of cracks and pores, i.e., damage, by product gases at the burn-front is a key step in the transition to convective burning. However, the relative influence of pre-existing damage and the evolution of deflagration-induced damage during the transition to convective burning is not well understood. The objective of this study is to investigate the role of microstructure and initial pressurization on deconsolidation. We performed simulations using the multi-physics hydrocode, ALE3D. HMX-Viton A served as our <span class="hlt">model</span> explosive. A Prout-Tompkins chemical kinetic <span class="hlt">model</span>, Vielle's Law pressure-dependent burning, Gruneisen equation-of-state, and simplified strength <span class="hlt">model</span> were used for the HMX. The propensity for deconsolidation increased with increasing defect size and decreasing initial pressurization, as measured by the increase in burning surface area. These studies are important because they enable the development of continuum-scale damage <span class="hlt">models</span> and the design of inherently safer explosives.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/servlets/purl/985829','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/servlets/purl/985829"><span id="translatedtitle">THE SIMULATION OF FINE SCALE NOCTURNAL BOUNDARY LAYER MOTIONS WITH A <span class="hlt">MESO-SCALE</span> ATMOSPHERIC <span class="hlt">MODEL</span></span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Werth, D.; Kurzeja, R.; Parker, M.</p> <p>2009-04-02</p> <p>A field project over the Atmospheric Radiation Measurement-Clouds and Radiation Testbed (ARM-CART) site during a period of several nights in September, 2007 was conducted to explore the evolution of the low-level jet (LLJ). Data was collected from a tower and a sodar and analyzed for turbulent behavior. To study the full range of nocturnal boundary layer (NBL) behavior, the Regional Atmospheric <span class="hlt">Modeling</span> System (RAMS) was used to simulate the ARM-CART NBL field experiment and validated against the data collected from the site. This <span class="hlt">model</span> was run at high resolution, and is ideal for calculating the interactions among the various motions within the boundary layer and their influence on the surface. The <span class="hlt">model</span> reproduces adequately the synoptic situation and the formation and dissolution cycles of the low-level jet, although it suffers from insufficient cloud production and excessive nocturnal cooling. The authors suggest that observed heat flux data may further improve the realism of the simulations both in the cloud formation and in the jet characteristics. In a higher resolution simulation, the NBL experiences motion on a range of timescales as revealed by a wavelet analysis, and these are affected by the presence of the LLJ. The <span class="hlt">model</span> can therefore be used to provide information on activity throughout the depth of the NBL.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2009JChPh.130n4908C','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2009JChPh.130n4908C"><span id="translatedtitle">Using stochastic <span class="hlt">models</span> calibrated from nanosecond nonequilibrium simulations to approximate <span class="hlt">mesoscale</span> information</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Calderon, Christopher P.; Janosi, Lorant; Kosztin, Ioan</p> <p>2009-04-01</p> <p>We demonstrate how the surrogate process approximation (SPA) method can be used to compute both the potential of mean force along a reaction coordinate and the associated diffusion coefficient using a relatively small number (10-20) of bidirectional nonequilibrium trajectories coming from a complex system. Our method provides confidence bands which take the variability of the initial configuration of the high-dimensional system, continuous nature of the work paths, and thermal fluctuations into account. Maximum-likelihood-type methods are used to estimate a stochastic differential equation (SDE) approximating the dynamics. For each observed time series, we estimate a new SDE resulting in a collection of SPA <span class="hlt">models</span>. The physical significance of the collection of SPA <span class="hlt">models</span> is discussed and methods for exploiting information in the population of estimated SPA <span class="hlt">models</span> are demonstrated and suggested. Molecular dynamics simulations of potassium ion dynamics inside a gramicidin A channel are used to demonstrate the methodology, although SPA-type <span class="hlt">modeling</span> has also proven useful in analyzing single-molecule experimental time series [J. Phys. Chem. B 113, 118 (2009)].</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2011AGUFM.A51E..05G','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2011AGUFM.A51E..05G"><span id="translatedtitle"><span class="hlt">Mesoscale</span> <span class="hlt">modeling</span> of smoke transport over the South Asian maritime continent: vertical distributions and topographic effect</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Ge, C.; Wang, J.; Yang, Z.; Hyer, E. J.; Reid, J. S.; Chew, B.; Mahamod, M.</p> <p>2011-12-01</p> <p>The online-coupled Weather Research and Forecasting <span class="hlt">model</span> with Chemistry (WRF-Chem) is used in conjunction with the FLAMBE MODIS-based biomass burning emissions to simulate the transport of smoke particles over the southeast Asian Maritime Continent (MC, 10°S - 10°N, 90°E-150°E) during September - October 2006 when the moderate El Nino event caused the largest region biomass burning outbreak since 1998. The <span class="hlt">modeled</span> smoke transport pathway is found to be consistent with the MODIS true color images. Quantitatively, the <span class="hlt">modeled</span> smoke particle mass can explain ~50% of temporal variability in 24-hour average observed PM10 at most ground stations, with linear correlation coefficients often larger than 0.7. Analysis of CALIOP data shows that smoke aerosols are primarily located within 3.5 km above the surface, and we found that smoke injection height in the <span class="hlt">model</span> should be at ~800 m above surface to best match CALIOP observations downwind, instead of 2 km as used in the past literature. Comparison of CALIOP data in October 2006 with that in other years (2007-2010) reveals that the peak of aerosol extinction always occurs at ~1 km above surface, but smoke events in 2006 doubled the aerosol extinction from the surface to 3.5 km. Numerical experiments further show that the Tama Abu topography in Malaysia Peninsula has a significant impact on smoke transport and the surface in the vicinity. A conceptual <span class="hlt">model</span>, based upon our analysis of two-month WRFchem simulation and satellite data, is proposed to explain the meteorological causes for smoke layers above the clouds as seen in the CALIOP data.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2009AGUFMED51A0518L','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2009AGUFMED51A0518L"><span id="translatedtitle">A Framework for the Abstraction of <span class="hlt">Mesoscale</span> <span class="hlt">Modeling</span> for Weather Simulation</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Limpasuvan, V.; Ujcich, B. E.</p> <p>2009-12-01</p> <p>Widely disseminated weather forecast results (e. g. from various national centers and private companies) are useful for typical users in gauging future atmospheric disturbances. However, these canonical forecasts may not adequately meet the needs of end-users in the various scientific fields since a predetermined <span class="hlt">model</span>, as structured by the <span class="hlt">model</span> administrator, produces these forecasts. To perform his/her own successful forecasts, a user faces a steep learning curve involving the collection of initial condition data (e.g. radar, satellite, and reanalyses) and operation of a suitable <span class="hlt">model</span> (and associated software/computing). In this project, we develop an intermediate (prototypical) software framework and a web-based front-end interface that allow for the abstraction of an advanced weather <span class="hlt">model</span> upon which the end-user can perform customizable forecasts and analyses. Having such an accessible, front-end interface for a weather <span class="hlt">model</span> can benefit educational programs at the secondary school and undergraduate level, scientific research in the fields like fluid dynamics and meteorology, and the general public. In all cases, our project allows the user to generate a localized domain of choice, run the desired forecast on a remote high-performance computer cluster, and visually see the results. For instance, an undergraduate science curriculum could incorporate the resulting weather forecast performed under this project in laboratory exercises. Scientific researchers and graduate students would be able to readily adjust key prognostic variables in the simulation within this project’s framework. The general public within the contiguous United States could also run a simplified version of the project’s software with adjustments in forecast clarity (spatial resolution) and region size (domain). Special cases of general interests, in which a detailed forecast may be required, would be over areas of possible strong weather activities.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3869703','PMC'); return false;" href="http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3869703"><span id="translatedtitle"><span class="hlt">Nested</span> Sampling for Bayesian <span class="hlt">Model</span> Comparison in the Context of Salmonella Disease Dynamics</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Dybowski, Richard; McKinley, Trevelyan J.; Mastroeni, Pietro; Restif, Olivier</p> <p>2013-01-01</p> <p>Understanding the mechanisms underlying the observed dynamics of complex biological systems requires the statistical assessment and comparison of multiple alternative <span class="hlt">models</span>. Although this has traditionally been done using maximum likelihood-based methods such as Akaike's Information Criterion (AIC), Bayesian methods have gained in popularity because they provide more informative output in the form of posterior probability distributions. However, comparison between multiple <span class="hlt">models</span> in a Bayesian framework is made difficult by the computational cost of numerical integration over large parameter spaces. A new, efficient method for the computation of posterior probabilities has recently been proposed and applied to complex problems from the physical sciences. Here we demonstrate how <span class="hlt">nested</span> sampling can be used for inference and <span class="hlt">model</span> comparison in biological sciences. We present a reanalysis of data from experimental infection of mice with Salmonella enterica showing the distribution of bacteria in liver cells. In addition to confirming the main finding of the original analysis, which relied on AIC, our approach provides: (a) integration across the parameter space, (b) estimation of the posterior parameter distributions (with visualisations of parameter correlations), and (c) estimation of the posterior predictive distributions for goodness-of-fit assessments of the <span class="hlt">models</span>. The goodness-of-fit results suggest that alternative mechanistic <span class="hlt">models</span> and a relaxation of the quasi-stationary assumption should be considered. PMID:24376528</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/abs/2012AGUFM.H33F1393K','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2012AGUFM.H33F1393K"><span id="translatedtitle">Multiscale analysis of surface soil moisture dynamics in a <span class="hlt">mesoscale</span> catchment utilizing an integrated ecohydrological <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>Korres, W.; Reichenau, T. G.; Schneider, K.</p> <p>2012-12-01</p> <p>Soil moisture is one of the fundamental variables in hydrology, meteorology and agriculture, influencing the partitioning of solar energy into latent and sensible heat flux as well as the partitioning of precipitation into runoff and percolation. Numerous studies have shown that in addition to natural factors (rainfall, soil, topography etc.) agricultural management is one of the key drivers for spatio-temporal patterns of soil moisture in agricultural landscapes. Interactions between plant growth, soil hydrology and soil nitrogen transformation processes are <span class="hlt">modeled</span> by using a dynamically coupled <span class="hlt">modeling</span> approach. The process-based ecohydrological <span class="hlt">model</span> components of the integrated decision support system DANUBIA are used to identify the important processes and feedbacks determining soil moisture patterns in agroecosystems. Integrative validation of plant growth and surface soil moisture dynamics serves as a basis for a spatially distributed <span class="hlt">modeling</span> analysis of surface soil moisture patterns in the northern part of the Rur catchment (1100 sq km), Western Germany. An extensive three year dataset (2007-2009) of surface soil moisture-, plant- (LAI, organ specific biomass and N) and soil- (texture, N, C) measurements was collected. Plant measurements were carried out biweekly for winter wheat, maize, and sugar beet during the growing season. Soil moisture was measured with three FDR soil moisture stations. Meteorological data was measured with an eddy flux station. The results of the <span class="hlt">model</span> validation showed a very good agreement between the <span class="hlt">modeled</span> plant parameters (biomass, green LAI) and the measured parameters with values between 0.84 and 0.98 (Willmotts index of agreement). The <span class="hlt">modeled</span> surface soil moisture (0 - 20 cm) showed also a very favorable agreement with the measurements for winter wheat and sugar beet with an RMSE between 1.68 and 3.45 Vol.-%. For maize, the RMSE was less favorable particularly in the 1.5 months prior to harvest. The <span class="hlt">modeled</span> soil</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2013AGUFM.T53B2572T','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2013AGUFM.T53B2572T"><span id="translatedtitle"><span class="hlt">Mesoscale</span> <span class="hlt">modeling</span> of grain fracturing in high porosity rocks using the strong discontinuity approach</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Tjioe, M.; Choo, J.; Borja, R. I.</p> <p>2013-12-01</p> <p>In previous studies, it has been found that two dominant micro-mechanisms play important roles in the deformation of high-porosity rocks. They are grain fracturing and crystal plasticity. Grain fracturing is a phenomenon where larger grains cleave to their smaller constituents as they respond to the stress concentration exerted on them close to the open pore spaces. Specimen-scale <span class="hlt">modeling</span> cannot reflect such mechanism so our investigation is carried out in the next smaller scale, namely the mesoscopic scale. We <span class="hlt">model</span> a solid matrix microstructure using finite element in which displacement discontinuity is introduced in each element where the slip condition has been exceeded. Such discontinuity is termed strong discontinuity and is characterized by zero band thickness and localized strain in the band that reaches infinity. For grains under compression, this slip condition is the cohesive-frictional law governing the behavior on the surface of discontinuity. The strong discontinuity in the grain scale is <span class="hlt">modeled</span> via an Assumed Enhanced Strain (AES) method formulated within the context of nonlinear finite elements. Through this method, we can <span class="hlt">model</span> grain-splitting as well as halos of cataclastic damage that are usually observed before a macropore collapses. The overall stress-strain curve and plastic slip of the mesoscopic element are then obtained and comparison to the crystal plasticity behavior is made to show the differences between the two mechanisms. We demonstrate that the incorporation of grain-fracturing and crystal plasticity can shed light onto the pore-scale deformation of high-porosity rocks.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2011APS..SHK.F1069S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2011APS..SHK.F1069S"><span id="translatedtitle"><span class="hlt">Mesoscale</span> <span class="hlt">Modeling</span> of Deflagration-Induced Deconsolidation in Polymer-Bonded Explosives</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Springer, H. Keo; Reaugh, J. E.; Glascoe, E. A.; Kercher, J. R.; Friedman, G.</p> <p>2011-06-01</p> <p>Initially intact polymer-bonded explosives can transition from conductive burning to more violent convective burning via rapid deconsolidation at higher pressures. The pressure-dependent infiltration of cracks and pores, i.e., damage, by product gases at the burn-front is a key step in the transition to convective burning. However, the relative influence of pre-existing damage and deflagration-induced damage on the transition to convective burning is not well understood. The objective of this study is to investigate the role of explosive constituent properties, microstructure, and deflagration velocity on deconsolidation. We performed simulations using the multi-physics hydrocode, ALE3D. HMX was used as the <span class="hlt">model</span> energetic grain. We used a JWL form for the unreacted and reacted equation-of-state of the HMX. Simplified strength and failure <span class="hlt">models</span> were used for the HMX and the binder. The propensity for deconsolidation increased with increasing grain volume fraction, increasing porosity, decreasing binder strength, and increasing deflagration velocity. These studies are important because they enable the development of deflagration-induced damage <span class="hlt">models</span>, as well as the design of inherently safer explosives. This work performed under the auspices of the U.S. DOE by LLNL under Contract DE-AC52-07NA27344. This work was funded by the Joint DoD/DOE Munitions Technology Development 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_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://adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2014MSMSE..22c4001H&link_type=ABSTRACT','NASAADS'); return false;" href="http://adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2014MSMSE..22c4001H&link_type=ABSTRACT"><span id="translatedtitle">Scale bridging between atomistic and <span class="hlt">mesoscale</span> <span class="hlt">modelling</span>: applications of amplitude equation descriptions</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Hüter, Claas; Nguyen, Chi-Dzu; Spatschek, Robert; Neugebauer, Jörg</p> <p>2014-04-01</p> <p>Amplitude equations are discussed as an extension of phase field <span class="hlt">models</span>, which contain atomic resolution and allow one to describe polycrystalline structures, lattice deformations and defects. The interaction of adjacent grains, which are separated by a thin melt layer, leads to structural interactions if the grains are slightly misplaced, similar to the concept of γ-surfaces. We are able to predict these interactions essentially analytically, leading to a superposition of short-ranged interaction terms related to the individual density waves. Deviations from the analytical predictions are found only at short distances between the grains and are most pronounced in situations with different ranges of the contributions. Furthermore, we demonstrate the ability of the amplitude equation <span class="hlt">model</span> to predict dislocation pairing transitions at high temperatures, which supports earlier findings using molecular dynamics and phase field crystal simulations. To effectively perform the numerical simulations, we present a way to implement the <span class="hlt">model</span> on graphics cards. An enormous acceleration of the code in comparison to a single CPU code by up to two orders of magnitude is reached.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2015MSMSE..23e5009X&link_type=ABSTRACT','NASAADS'); return false;" href="http://adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2015MSMSE..23e5009X&link_type=ABSTRACT"><span id="translatedtitle">Computational <span class="hlt">modelling</span> of <span class="hlt">mesoscale</span> dislocation patterning and plastic deformation of single crystals</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Xia, Shengxu; El-Azab, Anter</p> <p>2015-07-01</p> <p>We present a continuum dislocation dynamics <span class="hlt">model</span> that predicts the formation of dislocation cell structure in single crystals at low strains. The <span class="hlt">model</span> features a set of kinetic equations of the curl type that govern the space and time evolution of the dislocation density in the crystal. These kinetic equations are coupled to stress equilibrium and deformation kinematics using the eigenstrain approach. A custom finite element method has been developed to solve the coupled system of equations of dislocation kinetics and crystal mechanics. The results show that, in general, dislocations self-organize in patterns under their mutual interactions. However, the famous dislocation cell structure has been found to form only when cross slip is implemented in the <span class="hlt">model</span>. Cross slip is also found to lower the yield point, increase the hardening rate, and sustain an increase in the dislocation density over the hardening regime. Analysis of the cell structure evolution reveals that the average cell size decreases with the applied stress, which is consistent with the similitude principle.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016JESS..125..475R','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016JESS..125..475R"><span id="translatedtitle">Role of land state in a high resolution <span class="hlt">mesoscale</span> <span class="hlt">model</span> for simulating the Uttarakhand heavy rainfall event over India</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Rajesh, P. V.; Pattnaik, S.; Rai, D.; Osuri, K. K.; Mohanty, U. C.; Tripathy, S.</p> <p>2016-04-01</p> <p>In 2013, Indian summer monsoon witnessed a very heavy rainfall event (>30 cm/day) over Uttarakhand in north India, claiming more than 5000 lives and property damage worth approximately 40 billion USD. This event was associated with the interaction of two synoptic systems, i.e., intensified subtropical westerly trough over north India and north-westward moving monsoon depression formed over the Bay of Bengal. The event had occurred over highly variable terrain and land surface characteristics. Although global <span class="hlt">models</span> predicted the large scale event, they failed to predict realistic location, timing, amount, intensity and distribution of rainfall over the region. The goal of this study is to assess the impact of land state conditions in simulating this severe event using a high resolution <span class="hlt">mesoscale</span> <span class="hlt">model</span>. The land conditions such as multi-layer soil moisture and soil temperature fields were generated from High Resolution Land Data Assimilation (HRLDAS) <span class="hlt">modelling</span> system. Two experiments were conducted namely, (1) CNTL (Control, without land data assimilation) and (2) LDAS, with land data assimilation (i.e., with HRLDAS-based soil moisture and temperature fields) using Weather Research and Forecasting (WRF) <span class="hlt">modelling</span> system. Initial soil moisture correlation and root mean square error for LDAS is 0.73 and 0.05, whereas for CNTL it is 0.63 and 0.053 respectively, with a stronger heat low in LDAS. The differences in wind and moisture transport in LDAS favoured increased moisture transport from Arabian Sea through a convectively unstable region embedded within two low pressure centers over Arabian Sea and Bay of Bengal. The improvement in rainfall is significantly correlated to the persistent generation of potential vorticity (PV) in LDAS. Further, PV tendency analysis confirmed that the increased generation of PV is due to the enhanced horizontal PV advection component rather than the diabatic heating terms due to modified flow fields. These results suggest that, two</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/1985JAtS...42.2478O','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/1985JAtS...42.2478O"><span id="translatedtitle">A <span class="hlt">Modeling</span> Study of Heating and Drying Effects of Convective Clouds in an Extratropical <span class="hlt">Mesoscale</span> Convective System.</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Ogura, Yoshi; Jiang, Jih-Yih</p> <p>1985-12-01</p> <p>The two-dimensional version of the cumulus ensemble <span class="hlt">model</span> developed by Soong and Ogura is applied both to a prestorm situation and to the mature stage of the extratropical <span class="hlt">mesoscale</span> convective system (MCS) that developed on 10-11 April 1979 (AVE-SESAME-79 I) over the central United States. The objective is to investigate the statistical properties of convection, developing in response to an imposed large-scale forcing, and the thermodynamic feedback effect of clouds on the large-scale environment in midlatitudes. The result is compared to that recently obtained by Tao for a tropical rainband.The outstanding result of the <span class="hlt">model</span> integration for 17 h of physical time is that statistical properties of clouds averaged horizontally over 128 km of the <span class="hlt">model</span> domain undergo temporal variations for a given time-independent large-scale forcing, rather than settling down into a steady state. When applied to a prestorm situation, the <span class="hlt">model</span> predicts heavy precipitation that continues to fall for the first 5 h, followed by a 4 h period without precipitation. A second burst of deep convection then occurs. An analysis of the result reveals that the pause of precipitation occurs when the subcloud layer is dried up primarily due to the net vertical transport of moisture associated with clouds. Convection again starts developing when the moisture in the subcloud layer is replenished by the imposed large-scale forcing. The precipitation rate averaged over the precipitation period is found to exceed the supply of moisture by the large-scale forcing. The result implies that the fraction of moisture convergence in a vertical air column that contributes to moisten the environmental atmosphere in Kuo's cumulus parameterization scheme can be negative.Further, the result indicates the following: 1) The updraft mass flux increases with height until it reaches the local maximum at 350 mb, indicating that the cloud population is dominated by deep clouds, in contrast to the bimodal or broad</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/biblio/6434045','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/biblio/6434045"><span id="translatedtitle">A nonreflecting upper boundary condition for anelastic nonhydrostatic <span class="hlt">Mesoscale</span> gravity-wave <span class="hlt">models</span></span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Kim, Young-Joon; Kar, Sajal K.; Arakawa, Akio )</p> <p>1993-04-01</p> <p>A sponge layer is formulated to prevent spurious reflection of vertically propagating quasi-stationary gravity waves at the upper boundary of a two-dimensional numerical anelastic nonhydrostatic <span class="hlt">model</span>. The sponge layer includes damping of both Newtonian-cooling type and Rayleigh-friction type, whose coefficients are determined in such a way that the reflectivity of wave energy at the bottom of the layer is zero. Unlike the formulations in earlier studies, our formulation includes the effects of vertical discretization, vertical mean density variation, and nonhydrostaticity. This sponge formulation is found effective in suppressing false downward reflection of waves for various types of quasi-stationary forcing.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://ntrs.nasa.gov/search.jsp?R=19930052041&hterms=sponge&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D30%26Ntt%3Dsponge','NASA-TRS'); return false;" href="http://ntrs.nasa.gov/search.jsp?R=19930052041&hterms=sponge&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D30%26Ntt%3Dsponge"><span id="translatedtitle">A nonreflecting upper boundary condition for anelastic nonhydrostatic <span class="hlt">mesoscale</span> gravity-wave <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>Kim, Young-Joon; Kar, Sajal K.; Arakawa, Akio</p> <p>1993-01-01</p> <p>A sponge layer is formulated to prevent spurious reflection of vertically propagating quasi-stationary gravity waves at the upper boundary of a two-dimensional numerical anelastic nonhydrostatic <span class="hlt">model</span>. The sponge layer includes damping of both Newtonian-cooling type and Rayleigh-friction type, whose coefficients are determined in such a way that the reflectivity of wave energy at the bottom of the layer is zero. Unlike the formulations in earlier studies, our formulation includes the effects of vertical discretization, vertical mean density variation, and nonhydrostaticity. This sponge formulation is found effective in suppressing false downward reflection of waves for various types of quasi-stationary forcing.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015AGUFMNG13B..04G','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015AGUFMNG13B..04G"><span id="translatedtitle">Towards Exascale Computing with NUMA: an Element-based Galerkin Nonhydrostatic Global and <span class="hlt">Mesoscale</span> Atmospheric <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>Giraldo, F.; Mueller, A.; Kopera, M. A.; Abdi, D. S.; Wilcox, L.</p> <p>2015-12-01</p> <p>In this talk, we shall describe the NUMA atmospheric <span class="hlt">model</span>, focusing in particular on its unified continuous/discontinuous (CG and DG) Galerkin numerical methods that are used to represent the spatial derivatives. We shall describe how these two methods are formulated in a unified approach and the advantages that this brings. We will also report on the progress in extending NUMA to using adaptive mesh refinement. Lastly, we will report on the scalability and performance of NUMA on the leadership computing facilities (LCF) of the Department of Energy where we have scaled NUMA to over 3 million MPI threads achieving a 90% efficiency.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015AtmEn.100..167K','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015AtmEn.100..167K"><span id="translatedtitle">Urban air quality simulation in a high-rise building area using a CFD <span class="hlt">model</span> coupled with <span class="hlt">mesoscale</span> meteorological and chemistry-transport <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>Kwak, Kyung-Hwan; Baik, Jong-Jin; Ryu, Young-Hee; Lee, Sang-Hyun</p> <p>2015-01-01</p> <p>An integrated urban air quality <span class="hlt">modeling</span> system is established by coupling a computational fluid dynamics (CFD) <span class="hlt">model</span> with <span class="hlt">mesoscale</span> meteorological and chemistry-transport <span class="hlt">models</span>. The <span class="hlt">mesoscale</span> <span class="hlt">models</span> used are the weather research and forecasting (WRF) <span class="hlt">model</span> and the community multiscale air quality (CMAQ) <span class="hlt">model</span>, which provide the initial and time-dependent boundary conditions for the CFD <span class="hlt">model</span>. For the consistency of chemical processes in the CFD and CMAQ <span class="hlt">models</span>, the same chemical mechanism used in the CMAQ <span class="hlt">model</span> is implemented in the CFD <span class="hlt">model</span>. Urban air quality simulations are performed from 0900 to 1800 LT on 3 June 2010 in a high-rise building area of Seoul, Republic of Korea, where mobile emission sources are concentrated. The NO2 and O3 concentrations in the CFD simulation are evaluated with data measured at a roadside air quality monitoring station, showing better agreements than those in the CMAQ simulation. The NO2 and O3 concentration fields exhibit high spatial variabilities in the high-rise building area. The spatial variabilities near the surfaces are strongly associated with the heterogeneity of mobile emission on roads, whereas the spatial variabilities near the top of high-rise buildings are strongly associated with the heterogeneity of building geometry. The average NO2 and O3 concentrations (46 and 30 ppb, respectively, at z = 30 m) near the surfaces are considerably different from the NO2 and O3 concentrations in the CMAQ simulation (17 and 44 ppb, respectively, at z = 30 m), implying the insufficient urban surface representation in the CMAQ simulation. The heterogeneity of building geometry is found to enhance the vertical pollutant transport, whereas the heterogeneity of mobile emission is found to confine emitted pollutants near the surfaces. When the vertical mixing is efficient, the O3 concentration decreases in substantial vertical ranges with the same amount of NOx emission. The integrated urban air quality <span class="hlt">modeling</span> system realistically</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/biblio/1157123','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/biblio/1157123"><span id="translatedtitle">Lipid-Based Nanodiscs as <span class="hlt">Models</span> for Studying <span class="hlt">Mesoscale</span> Coalescence A Transport Limited Case</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Hu, Andrew; Fan, Tai-Hsi; Katsaras, John; Xia, Yan; Li, Ming; Nieh, Mu-Ping</p> <p>2014-01-01</p> <p>Lipid-based nanodiscs (bicelles) are able to form in mixtures of long- and short-chain lipids. Initially, they are of uniform size but grow upon dilution. Previously, nanodisc growth kinetics have been studied using time-resolved small angle neutron scattering (SANS), a technique which is not well suited for probing their change in size immediately after dilution. To address this, we have used dynamic light scattering (DLS), a technique which permits the collection of useful data in a short span of time after dilution of the system. The DLS data indicate that the negatively charged lipids in nanodiscs play a significant role in disc stability and growth. Specifically, the charged lipids are most likely drawn out from the nanodiscs into solution, thereby reducing interparticle repulsion and enabling the discs to grow. We describe a population balance <span class="hlt">model</span>, which takes into account Coulombic interactions and adequately predicts the initial growth of nanodiscs with a single parameter i.e., surface potential. The results presented here strongly support the notion that the disc coalescence rate strongly depends on nanoparticle charge density. The present system containing low-polydispersity lipid nanodiscs serves as a good <span class="hlt">model</span> for understanding how charged discoidal micelles coalesce.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014JAP...116u4904P','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014JAP...116u4904P"><span id="translatedtitle">Mathematical <span class="hlt">modeling</span> of a four-stroke resonant engine for micro and <span class="hlt">mesoscale</span> applications</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Preetham, B. S.; Anderson, M.; Richards, C.</p> <p>2014-12-01</p> <p>In order to mitigate frictional and leakage losses in small scale engines, a compliant engine design is proposed in which the piston in cylinder arrangement is replaced by a flexible cavity. A physics-based nonlinear lumped-parameter <span class="hlt">model</span> is derived to predict the performance of a prototype engine. The <span class="hlt">model</span> showed that the engine performance depends on input parameters, such as heat input, heat loss, and load on the engine. A sample simulation for a reference engine with octane fuel/air ratio of 0.043 resulted in an indicated thermal efficiency of 41.2%. For a fixed fuel/air ratio, higher output power is obtained for smaller loads and vice-versa. The heat loss from the engine and the work done on the engine during the intake stroke are found to decrease the indicated thermal efficiency. The ratio of friction work to indicated work in the prototype engine is about 8%, which is smaller in comparison to the traditional reciprocating engines.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2002EGSGA..27.6856D','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2002EGSGA..27.6856D"><span id="translatedtitle">Regional Assesssment and Monitoring of Teh Carbon Balance Within Europe (recab): Experimental Strategy and <span class="hlt">Mesoscale</span> <span class="hlt">Modeling</span> Preliminary Results</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Dolman, H.; de Martino, B.; Gioli, B.; Hutjes, R. W. A.; Lindroth, A.; Miglietta, F.; Millan, M. M.; Sanz, M. J.; Schumacher, M.</p> <p></p> <p>The aim of RECAB project (EU project EVK2-CT-1999-00034) is to quantify the contribution of fossil fuel and biospheric sources and sinks of CO2 in Europe to the atmospheric concentration at the regional scale by using a generic coupled bio- sphere atmosphere <span class="hlt">modelling</span> and experimental approach. To achieve this, a coupled <span class="hlt">mesoscale</span>-land surface <span class="hlt">model</span> incorporating the biosphere is being developed; a flux aircraft for low flying purposes was set up and is being used for the regional flux mea- surements (Sky Arrow 650 TCN version ERA); and a system for collecting flask sam- ples to determine gas concentrations (CH4, CO2 and N2O) and isotope ratios (ä13C and ä18O in CO2) is operative on small aircrafts is also set up. The ERA represents the first attempt in Europe to measure surface mass and energy fluxes using airborne eddy covariance. The ERA uses the Best Aircraft Turbulence Probe (BAT) probe that is being developed by NOAA and Airborne Research Australia (ARA). The BAT in- corporates a pressure sphere housing with a synthesis of differential GPS (DGPS), solid-state sensors, and electronic and aerodynamic technology to allow high fidelity turbulence measurements from any aeroplane. CO2 and water vapour concentrations are measured using a fast response open-path infrared gas analyser (LiCor7500) which is mounted on the aircraft nose. For the flask sampling air probes are taken as twin pairs at different flight levels. During the flights the track is recorded by GPS and meteorological parameters as also the CO2 concentration (LiCor6251) are measured online to employ a CBL-Budget-Method as another approach. Additional air probes are taken with a similar sampling unit at ground level within sites of characteristic land use for gas concentration analyses and isotope ratio determination. Three summer (Valencia, Spain; Hainich, Germany; Norunda, Sweden) and three winter (Valencia; 1 Hainich; Loobos, Netherlands) experimental campaigns were successfully executed</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2010EGUGA..12.5328V','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2010EGUGA..12.5328V"><span id="translatedtitle">Defining environmental flows requirements at regional scale by using <span class="hlt">meso-scale</span> habitat <span class="hlt">models</span> and catchments classification</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Vezza, Paolo; Comoglio, Claudio; Rosso, Maurizio</p> <p>2010-05-01</p> <p>The alterations of the natural flow regime and in-stream channel modification due to abstraction from watercourses act on biota through an hydraulic template, which is mediated by channel morphology. <span class="hlt">Modeling</span> channel hydro-morphology is needed in order to evaluate how much habitat is available for selected fauna under specific environmental conditions, and consequently to assist decision makers in planning options for regulated river management. <span class="hlt">Meso-scale</span> habitat <span class="hlt">modeling</span> methods (e.g., MesoHABSIM) offer advantages over the traditional physical habitat evaluation, involving a larger range of habitat variables, allowing longer length of surveyed rivers and enabling understanding of fish behavior at larger spatial scale. In this study we defined a bottom-up method for the ecological discharge evaluation at regional scale, focusing on catchments smaller than 50 km2, most of them located within mountainous areas of Apennines and Alps mountain range in Piedmont (NW Italy). Within the regional study domain we identified 30 representative catchments not affected by water abstractions in order to build up the habitat-flow relationship, to be used as reference when evaluating regulated watercourses or new projects. For each stream we chose a representative reach and obtained fish data by sampling every single functional habitat (i.e. meso-habitat) within the site, keeping separated each area by using nets. The target species were brown trout (Salmo trutta), marble trout (Salmo trutta marmoratus), bullhead (Cottus gobius), chub (Leuciscus cephalus), barbel (Barbus barbus), vairone (Leuciscus souffia) and other rheophilic Cyprinids. The fish habitat suitability criteria was obtained from the observation of habitat use by a selected organism described with a multivariate relationship between habitat characteristics and fish presence. Habitat type, mean slope, cover, biotic choriotop and substrate, stream depth and velocity, water pH, temperature and percentage of dissolved</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015GMD.....8.1919F','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015GMD.....8.1919F"><span id="translatedtitle">AROME-WMED, a real-time <span class="hlt">mesoscale</span> <span class="hlt">model</span> designed for the HyMeX special observation periods</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Fourrié, N.; Bresson, É.; Nuret, M.; Jany, C.; Brousseau, P.; Doerenbecher, A.; Kreitz, M.; Nuissier, O.; Sevault, E.; Bénichou, H.; Amodei, M.; Pouponneau, F.</p> <p>2015-07-01</p> <p>During autumn 2012 and winter 2013, two special observation periods (SOPs) of the HYdrological cycle in the Mediterranean EXperiment (HyMeX) took place. For the preparatory studies and to support the instrument deployment during the field campaign, a dedicated version of the operational convective-scale Application of Research to Operations at <span class="hlt">Mesoscale</span> (AROME)-France <span class="hlt">model</span> was developed: the AROME-WMED (West Mediterranean Sea) <span class="hlt">model</span>. It covers the western Mediterranean basin with a 48 h forecast range. It provided real-time analyses and forecasts which were sent daily to the HyMeX operational centre to forecast high-precipitation events and to help decision makers on the deployment of meteorological instruments. This paper presents the main features of this numerical weather prediction system in terms of data assimilation and forecast. Some specific data of the HyMeX SOP were assimilated in real time. The forecast skill of AROME-WMED is then assessed with objective scores and compared to the operational AROME-France <span class="hlt">model</span>, for both autumn 2012 (05 September to 06 November 2012) and winter 2013 (01 February to 15 March 2013) SOPs. The overall performance of AROME-WMED is good for the first HyMeX special observation period (SOP1) (i.e. mean 2 m temperature root mean square error (RMSE) of 1.7 °C and mean 2 m relative humidity RMSE of 10 % for the 0-30 h forecast ranges) and similar to those of AROME-France for the 0-30 h common forecast range (maximal absolute difference of 2 m temperature RMSE of 0.2 °C and 0.21 % for the 2 m relative humidity); conversely, for the 24-48 h forecast range it is less accurate (relative loss between 10 and 12 % in 2 m temperature and relative humidity RMSE, and equitable threat score (ETS) for 24 h accumulated rainfall), but it remains useful for scheduling observation deployment. The characteristics of parameters, such as precipitation, temperature or humidity, are illustrated by one heavy precipitation case study that occurred</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015AGUFM.A11J0199B','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015AGUFM.A11J0199B"><span id="translatedtitle">Constraining Methane Emissions from Natural Gas Production in Northeastern Pennsylvania Using Aircraft Observations 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>Barkley, Z.; Davis, K.; Lauvaux, T.; Miles, N.; Richardson, S.; Martins, D. K.; Deng, A.; Cao, Y.; Sweeney, C.; Karion, A.; Smith, M. L.; Kort, E. A.; Schwietzke, S.</p> <p>2015-12-01</p> <p>Leaks in natural gas infrastructure release methane (CH4), a potent greenhouse gas, into the atmosphere. The estimated fugitive emission rate associated with the production phase varies greatly between studies, hindering our understanding of the natural gas energy efficiency. This study presents a new application of inverse methodology for estimating regional fugitive emission rates from natural gas production. Methane observations across the Marcellus region in northeastern Pennsylvania were obtained during a three week flight campaign in May 2015 performed by a team from the National Oceanic and Atmospheric Administration (NOAA) Global Monitoring Division and the University of Michigan. In addition to these data, CH4 observations were obtained from automobile campaigns during various periods from 2013-2015. An inventory of CH4 emissions was then created for various sources in Pennsylvania, including coalmines, enteric fermentation, industry, waste management, and unconventional and conventional wells. As a first-guess emission rate for natural gas activity, a leakage rate equal to 2% of the natural gas production was emitted at the locations of unconventional wells across PA. These emission rates were coupled to the Weather Research and Forecasting <span class="hlt">model</span> with the chemistry module (WRF-Chem) and atmospheric CH4 concentration fields at 1km resolution were generated. Projected atmospheric enhancements from WRF-Chem were compared to observations, and the emission rate from unconventional wells was adjusted to minimize errors between observations and simulation. We show that the <span class="hlt">modeled</span> CH4 plume structures match observed plumes downwind of unconventional wells, providing confidence in the methodology. In all cases, the fugitive emission rate was found to be lower than our first guess. In this initial emission configuration, each well has been assigned the same fugitive emission rate, which can potentially impair our ability to match the observed spatial variability</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/biblio/7113532','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/biblio/7113532"><span id="translatedtitle">Simulations of the Amazon Basin circulation using the Pennsylvania State University/National Center for Atmospheric Research <span class="hlt">mesoscale</span> <span class="hlt">model</span></span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Hahmann, A.N.</p> <p>1992-01-01</p> <p>A regional <span class="hlt">model</span> has been used to investigate dynamical processes that control the circulation over the Amazon Basin. The application of a regional <span class="hlt">model</span> to the Amazon Basin is unique and the method in which the <span class="hlt">model</span> output is diagnosed is distinct. Two synoptic cases describe the ability of the regional <span class="hlt">model</span> to simulate the circulation over the Amazon Basin. The first case, 15-17 April 1990, represents an example of the dominant circulation over the basin during the summer. The second case study occurs 27 February-1 March 1990. At the onset of this period, a vigorous trough is located in the subtropical westerlies of the Southern Hemisphere, which promotes advection of drier air by the low-level southerly flow into the southern part of the Basin. There is limited agreement between the observed circulation and the <span class="hlt">model</span> simulations for the case studies. The <span class="hlt">model</span> appears to simulate a number of dynamical processes known to take place. The timing of individual rain bands and their locations differ significantly from those observed. The sensitivity of the <span class="hlt">model</span> simulation to the size of the grid spacing and the domain reveal that the regional circulation is most economically simulated with a <span class="hlt">nested</span> domain and 60 km grid spacing. Larger grid spacings lead to excessive rainfall totals near the Andes Mountains and circulations that are unrealistic. Restricted domains (Amazon Basin only) produce excessive precipitation along the horizontal boundaries. <span class="hlt">Model</span> simulations using several different combinations of convective and explicit precipitation parameterizations are performed. Experiments using the explicit moisture scheme without a cumulus parameterization scheme show the development of grid point instabilities. These instabilities result from interaction processes among latent heat release, large-scale moisture convergence, and surface pressure. When the Kuo-Anthes cumulus parameterization is included, grid point instabilities are substantially reduced.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/servlets/purl/10128282','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/servlets/purl/10128282"><span id="translatedtitle">Application of an advanced atmospheric <span class="hlt">mesoscale</span> <span class="hlt">model</span> to dispersion in the Rocky Flats, Colorado vicinity</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Poulos, G.S.; Bossert, J.E.</p> <p>1993-02-01</p> <p>Atmospheric Studies in Complex Terrain (ASCOT) program sponsored a field experiment in the winter of 1991 near Rocky Flats, Colorado. Both meteorological and tracer dispersion measurements were taken. These two data sets provided an opportunity to investigate the influence of terrain-generated, radiatively-driven flows on the dispersion of the tracer. We use the Regional Atmospheric <span class="hlt">Modeling</span> System (RAMS), originally developed at Colorado State University, to simulate meteorological conditions and tracer dispersion on the case night of 4-5 February 1991. The simulations described herein reveal considerable information about the extent to which the Rocky Mountains influence the flow along the Front Range , the importance of diffusion when simulating drainage flows and the computing needs of simulations in complex terrain regions.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/servlets/purl/6889186','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/servlets/purl/6889186"><span id="translatedtitle">Application of an advanced atmospheric <span class="hlt">mesoscale</span> <span class="hlt">model</span> to dispersion in the Rocky Flats, Colorado vicinity</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Poulos, G.S.; Bossert, J.E.</p> <p>1993-01-01</p> <p>Atmospheric Studies in Complex Terrain (ASCOT) program sponsored a field experiment in the winter of 1991 near Rocky Flats, Colorado. Both meteorological and tracer dispersion measurements were taken. These two data sets provided an opportunity to investigate the influence of terrain-generated, radiatively-driven flows on the dispersion of the tracer. We use the Regional Atmospheric <span class="hlt">Modeling</span> System (RAMS), originally developed at Colorado State University, to simulate meteorological conditions and tracer dispersion on the case night of 4-5 February 1991. The simulations described herein reveal considerable information about the extent to which the Rocky Mountains influence the flow along the Front Range , the importance of diffusion when simulating drainage flows and the computing needs of simulations in complex terrain regions.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2006PhRvL..96a8102F','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2006PhRvL..96a8102F"><span id="translatedtitle"><span class="hlt">Mesoscale</span> Computer <span class="hlt">Modeling</span> of Lipid-DNA Complexes for Gene Therapy</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Farago, Oded; Grønbech-Jensen, Niels; Pincus, Philip</p> <p>2006-01-01</p> <p>We report on a molecular simulation method, which captures the self-assembly of cationic lipid-DNA (CL-DNA) gene delivery complexes. Computational efficiency required for large length- and time-scale simulations is achieved through a coarse-grained representation of the intramolecular details and via intermolecular potentials, which effectively mimic the hydrophobic effect without an explicit solvent. The broad utility of the <span class="hlt">model</span> is illustrated by demonstrating excellent agreement with x-ray diffraction experimental data for the dependence of the spacing between DNA chains on the concentration of CLs. At high concentrations, the large electrostatic pressure induces the formation of pores in the membranes through which the DNA molecules may escape the complex. We relate this observation to the origin of recently observed enhanced transfection efficiency of lamellar CL-DNA complexes at high charge densities.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/servlets/purl/861016','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/servlets/purl/861016"><span id="translatedtitle">Impact of Agricultural Practice on Regional Climate in a CoupledLand Surface <span class="hlt">Mesoscale</span> <span class="hlt">Model</span></span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Cooley, H.S.; Riley, W.J.; Torn, M.S.; He, Y.</p> <p>2004-07-01</p> <p>The land surface has been shown to form strong feedbacks with climate due to linkages between atmospheric conditions and terrestrial ecosystem exchanges of energy, momentum, water, and trace gases. Although often ignored in <span class="hlt">modeling</span> studies, land management itself may form significant feedbacks. Because crops are harvested earlier under drier conditions, regional air temperature, precipitation, and soil moisture, for example, affect harvest timing, particularly of rain-fed crops. This removal of vegetation alters the land surface characteristics and may, in turn, affect regional climate. We applied a coupled climate(MM5) and land-surface (LSM1) <span class="hlt">model</span> to examine the effects of early and late winter wheat harvest on regional climate in the Department of Energy Atmospheric Radiation Measurement (ARM) Climate Research Facility in the Southern Great Plains, where winter wheat accounts for 20 percent of the land area. Within the winter wheat region, simulated 2 m air temperature was 1.3 C warmer in the Early Harvest scenario at mid-day averaged over the two weeks following harvest. Soils in the harvested area were drier and warmer in the top 10 cm and wetter in the 10-20 cm layer. Midday soils were 2.5 C warmer in the harvested area at mid-day averaged over the two weeks following harvest. Harvest also dramatically altered latent and sensible heat fluxes. Although differences between scenarios diminished once both scenarios were harvested, the short-term impacts of land management on climate were comparable to those from land cover change demonstrated in other studies.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2013BoLMe.146..297V','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2013BoLMe.146..297V"><span id="translatedtitle">Cross-Spectra Over the Sea from 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>Vincent, C. L.; Larsén, X. G.; Larsen, S. E.; Sørensen, P.</p> <p>2013-02-01</p> <p>Cospectra and quadrature spectra are calculated for six pairs of tall offshore measurement masts near the Horns Rev I wind farm in the Danish North Sea and the Nysted wind farm in the Baltic sea. The mast-pairs are separated from one another by horizontal distances of 2.13-12.4 km. Cospectra and quadrature spectra for the two sites are classified in terms of the angle between the mean wind direction and the line connecting each pair of masts. The frequency axes of the spectra are normalized to remove the effect of mean wind speed and separation distance. Results indicate a larger contribution to the quadrature spectrum for flow from the sea than for flow from the land, and the patterns in the spectra are clearer and better defined for Horns Rev I (which has a long uninterrupted sea-fetch from the west) than for Nysted (which is surrounded by a more complicated coastline). The analysis is replicated based on 3-month simulations using the weather research and forecasting (WRF) numerical <span class="hlt">model</span> with a horizontal grid spacing of 2 km. For the sea-fetch directions, good agreement in spectral properties between the <span class="hlt">model</span> and observations is found. Analytical expressions based on the properties of the cross-correlation function and an exponentially decaying coherence function are fitted to the normalized cospectra and quadrature spectra. The expressions are shown to be a good fit to the spectra calculated from the WRF simulations and to the observed spectra for directions with a long sea-fetch, which suggests that to a good approximation, the average cospectra and quadrature spectra over the sea can be written as functions of frequency, mean wind speed, separation distance and the angle between the wind direction and the orientation of the masts.</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://adsabs.harvard.edu/abs/2016JChPh.145n4109D','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016JChPh.145n4109D"><span id="translatedtitle">cDPD: A new dissipative particle dynamics method for <span class="hlt">modeling</span> electrokinetic phenomena at the <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>Deng, Mingge; Li, Zhen; Borodin, Oleg; Karniadakis, George Em</p> <p>2016-10-01</p> <p>We develop a "charged" dissipative particle dynamics (cDPD) <span class="hlt">model</span> for simulating mesoscopic electrokinetic phenomena governed by the stochastic Poisson-Nernst-Planck and the Navier-Stokes equations. Specifically, the transport equations of ionic species are incorporated into the DPD framework by introducing extra degrees of freedom and corresponding evolution equations associated with each DPD particle. Diffusion of ionic species driven by the ionic concentration gradient, electrostatic potential gradient, and thermal fluctuations is captured accurately via pairwise fluxes between DPD particles. The electrostatic potential is obtained by solving the Poisson equation on the moving DPD particles iteratively at each time step. For charged surfaces in bounded systems, an effective boundary treatment methodology is developed for imposing both the correct hydrodynamic and electrokinetics boundary conditions in cDPD simulations. To validate the proposed cDPD <span class="hlt">model</span> and the corresponding boundary conditions, we first study the electrostatic structure in the vicinity of a charged solid surface, i.e., we perform cDPD simulations of the electrostatic double layer and show that our results are in good agreement with the well-known mean-field theoretical solutions. We also simulate the electrostatic structure and capacity densities between charged parallel plates in salt solutions with different salt concentrations. Moreover, we employ the proposed methodology to study the electro-osmotic and electro-osmotic/pressure-driven flows in a micro-channel. In the latter case, we simulate the dilute poly-electrolyte solution drifting by electro-osmotic flow in a micro-channel, hence demonstrating the flexibility and capability of this method in studying complex fluids with electrostatic interactions at the micro- and nano-scales.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/19960034359','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19960034359"><span id="translatedtitle">Forecast skill of a high-resolution real-time <span class="hlt">mesoscale</span> <span class="hlt">model</span> designed for weather support of operations at 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>Taylor, Gregory E.; Zack, John W.; Manobianco, John</p> <p>1994-01-01</p> <p>NASA funded <span class="hlt">Mesoscale</span> Environmental Simulations and Operations (MESO), Inc. to develop a version of the <span class="hlt">Mesoscale</span> Atmospheric Simulation System (MASS). The <span class="hlt">model</span> has been modified specifically for short-range forecasting in the vicinity of KSC/CCAS. To accomplish this, the <span class="hlt">model</span> domain has been limited to increase the number of horizontal grid points (and therefore grid resolution) and the <span class="hlt">model</span>' s treatment of precipitation, radiation, and surface hydrology physics has been enhanced to predict convection forced by local variations in surface heat, moisture fluxes, and cloud shading. The objective of this paper is to (1) provide an overview of MASS including the real-time initialization and configuration for running the data pre-processor and <span class="hlt">model</span>, and (2) to summarize the preliminary evaluation of the <span class="hlt">model</span>'s forecasts of temperature, moisture, and wind at selected rawinsonde station locations during February 1994 and July 1994. MASS is a hydrostatic, three-dimensional <span class="hlt">modeling</span> system which includes schemes to represent planetary boundary layer processes, surface energy and moisture budgets, free atmospheric long and short wave radiation, cloud microphysics, and sub-grid scale moist convection.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/biblio/1020397','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/biblio/1020397"><span id="translatedtitle">Performance of <span class="hlt">mesoscale</span> <span class="hlt">modeling</span> methods for predicting microstructure, mobility and rheology of charged suspensions.</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Pierce, Flint; Grillet, Anne Mary; Grest, Gary Stephen; Lechman, Jeremy B.; Plimpton, Steven James; in't Veld, Pieter J.; Schunk, Peter Randall; Heine, D. R.; Stoltz, C.; Weiss, Horst; Jendrejack, R.; Petersen, Matthew K.</p> <p>2010-06-01</p> <p>In this presentation we examine the accuracy and performance of a suite of discrete-element-<span class="hlt">modeling</span> approaches to predicting equilibrium and dynamic rheological properties of polystyrene suspensions. What distinguishes each approach presented is the methodology of handling the solvent hydrodynamics. Specifically, we compare stochastic rotation dynamics (SRD), fast lubrication dynamics (FLD) and dissipative particle dynamics (DPD). Method-to-method comparisons are made as well as comparisons with experimental data. Quantities examined are equilibrium structure properties (e.g. pair-distribution function), equilibrium dynamic properties (e.g. short- and long-time diffusivities), and dynamic response (e.g. steady shear viscosity). In all approaches we deploy the DLVO potential for colloid-colloid interactions. Comparisons are made over a range of volume fractions and salt concentrations. Our results reveal the utility of such methods for long-time diffusivity prediction can be dubious in certain ranges of volume fraction, and other discoveries regarding the best formulation to use in predicting rheological response.</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/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..1810294R','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016EGUGA..1810294R"><span id="translatedtitle">Impact of observations in a <span class="hlt">mesoscale</span> NWP <span class="hlt">model</span> in the Arctic</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Randriamampianina, Roger; Máté, Mile; Guedj, Stephanie; Schyberg, Harald</p> <p>2016-04-01</p> <p>In the frame of the EU-funded project ACCESS (Arctic Climate Change, Economy and Society), MET Norway aimed 1) to describe the present monitoring and forecasting capabilities in the Arctic; and 2) to identify the key factors limiting the forecasting capabilities and to give recommendations on key areas to improve the forecasting capabilities in the Arctic. The first task was assessed using observing system experiments (OSE), while second one was evaluated applying observing system simulation experiments (OSSE). We have observed that the NWP forecast quality is lower in the Arctic than in the regions further south. An earlier research indicated that one of factors behind this is the composition of the observing system in the Arctic, in particular the scarceness of conventional observations. To further assess possible strategies for alleviating the situation and propose scenarios for a future Arctic observing system, we have performed a set of experiments to gain a more detailed insight in the contribution of the components of the present observing system in a regional state-of-the-art non-hydrostatic NWP <span class="hlt">model</span>. These observing system experiments have been evaluated 1) in terms of a measure of the information content of observations with respect to analysis quality and 2) with respect to the impact on forecasts assessed (a) through case studies, (b) through a norm measuring the impact on forecasts and (c) through the quality of forecasts verified with available reference observations. The OSE studies show that conventional observations (Synop, Buoys) can play an important role in correcting the surface state of the <span class="hlt">model</span>, but prove that the present upper-air conventional (Radiosondes, Arcraft) observations in the area are too scarce to have a significant effect on forecasts. We demonstrate that satellite sounding data play important role in improving forecasts quality at present. This is the case with the satellite temperature sounding data (AMSU-A, IASI), as well as</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2009AIPC.1195.1331B&link_type=ABSTRACT','NASAADS'); return false;" href="http://adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2009AIPC.1195.1331B&link_type=ABSTRACT"><span id="translatedtitle">a Review of <span class="hlt">Mesoscale</span> Simulations of Granular Materials</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Borg, J. P.; Vogler, T. J.; Fraser, A.</p> <p>2009-12-01</p> <p>With the advent of increased computing power, <span class="hlt">mesoscale</span> simulations have been used to explore grain level phenomenology of dynamic compaction events of various heterogenous systems including foams, reactive materials and porous granular materials. This paper presents an overview of several <span class="hlt">mesoscale</span> studies on a variety of materials including tungsten carbide, wet and dry sand, and an inert mixture of Al-MnO2-Epoxy. This paper focuses on relating bulk and compaction wave phenomenology from the <span class="hlt">mesoscale</span> <span class="hlt">modeling</span> to experimental results and exploring the nature of the compaction wave. In addition, lessons learned during these explorations, <span class="hlt">modeling</span> techniques, strengths and weaknesses of hydrodynamic <span class="hlt">mesoscale</span> simulations are also discussed.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/servlets/purl/1021054','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/servlets/purl/1021054"><span id="translatedtitle"><span class="hlt">Mesoscale</span> and Large-Eddy Simulations for Wind Energy</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Marjanovic, N</p> <p>2011-02-22</p> <p>Operational wind power forecasting, turbine micrositing, and turbine design require high-resolution simulations of atmospheric flow over complex terrain. The use of both Reynolds-Averaged Navier Stokes (RANS) and large-eddy (LES) simulations is explored for wind energy applications using the Weather Research and Forecasting (WRF) <span class="hlt">model</span>. To adequately resolve terrain and turbulence in the atmospheric boundary layer, grid <span class="hlt">nesting</span> is used to refine the grid from <span class="hlt">mesoscale</span> to finer scales. This paper examines the performance of the grid <span class="hlt">nesting</span> configuration, turbulence closures, and resolution (up to as fine as 100 m horizontal spacing) for simulations of synoptically and locally driven wind ramping events at a West Coast North American wind farm. Interestingly, little improvement is found when using higher resolution simulations or better resolved turbulence closures in comparison to observation data available for this particular site. This is true for week-long simulations as well, where finer resolution runs show only small changes in the distribution of wind speeds or turbulence intensities. It appears that the relatively simple topography of this site is adequately resolved by all <span class="hlt">model</span> grids (even as coarse as 2.7 km) so that all resolutions are able to <span class="hlt">model</span> the physics at similar accuracy. The accuracy of the results is shown in this paper to be more dependent on the parameterization of the land-surface characteristics such as soil moisture rather than on grid resolution.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2006PhDT.......154H','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2006PhDT.......154H"><span id="translatedtitle"><span class="hlt">Mesoscale</span> <span class="hlt">modeling</span> and computer simulation of tethered nanorod "shape amphiphile" assemblies</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Horsch, Mark A.</p> <p></p> <p>The goal of this thesis is to elucidate the parameters that strongly influence the self-assembled morphologies formed by tethered nanoparticle, "shape amphiphiles". Minimal <span class="hlt">models</span> are developed which capture the geometry and rigidity of the particles, the immiscibility between the particle and tether, and the tether connectivity and flexibility. This work focuses on the self-assembly of tethered rods a class of shape amphiphile where the rigid block is rod-like. The work presented here demonstrates that in addition to forming micelles, cylinders, bicontinuous, and sheet-like morphologies additional local ordering arises due to the geometry or anisotropy of the rigid block. For example, at high concentrations tethered rods are observed to form monolayer smectic morphologies when the solvent is good for the tether and poor for the rod, while, mono-tethered spheres self-assemble into bilayer structures. The number of tethers also influences the self-assembly. For example, di-tethered spheres self-assemble into monolayers in contrast to the bilayers formed when only a single tether is attached to the sphere. For the tethered rods in selective solvent, our simulations predict several novel phases. In the case of end-tethered rods, a novel hexagonally arranged chiral cylinder morphology was observed. Other morphologies such as the tetragonally perforated and hexagonally perforated lamellar phases were observed. These phases have been observed in experimental rod coil copolymers but have not been previously predicted by simulation or theory. In the case of side-tethered rods several novel phases have been identified in this work including rectangular centered stepped ribbons, and bilayer phases, one with P2 symmetry and the other with Cmm symmetry, are predicted. Of particular interest may be the orientation of the rods in the stepped ribbon phase, wherein the long axis of the rod is parallel to the major axis of the ribbon. For end-tethered rods in a neat system two</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2009PhDT.........5I','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2009PhDT.........5I"><span id="translatedtitle"><span class="hlt">Mesoscale</span> <span class="hlt">modeling</span> and computer simulation of tethered nanoparticle "Shape-amphiphile" assemblies</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Iacovella, Christopher R.</p> <p></p> <p>In this dissertation, we explore the use of polymer-tethered nanoparticles as a means to self-assemble highly ordered arrays of nanoparticles and nanometer-sized domains. We perform Brownian dynamics simulations to study the self-assembly of polymer functionalized spherical and rod-like nanoparticles. Immiscibility between tethers and nanoparticles facilitates assembly into highly ordered structures reminiscent of phases formed by surfactants and block copolymers, but with greater complexity. We explore the influence of key factors such as the nanoparticle size and shape, tether architecture, solvent selectivity, and bulk volume fraction on the resulting structures. In this thesis we perform several studies. First, we explore the phase behavior of mono-tethered nanospheres. Under solvent conditions that are poor for the tethers, we find phase behavior that is similar to surfactants with structures including lamellae, perforated lamellae, hexagonally packed cylinders, and spherical micelles. We report quasicrystalline-like ordering between the spherical micelles and propose an entropic <span class="hlt">model</span> to explain this behavior. We also explore the phase behavior of a mono-tethered nanosphere system where nanospheres are in poor solvent. We find phases similar to surfactants including lamellae, perforated lamellae, double gyroid, and hexagonally packed cylinders. We see a predominance of icosahedral arrangements of nanospheres in phases with 2D confinement and crystalline packing of nanospheres in structures with 1D confinement. We also compare and contrast the formation of the double gyroid structure for tethered nanospheres and tethered nanorods. We show that the ability of the nanoparticles to locally order into icosahedra (nanospheres) and hexagonally splayed bundles (nanorods) reduces packing frustration making these structures more stable than their block copolymer counterparts. We also explore the phase behavior of di-tethered nanospheres. We find a complex phase</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2010PhDT.......129T','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2010PhDT.......129T"><span id="translatedtitle"><span class="hlt">Mesoscale</span> <span class="hlt">modeling</span> and computational simulation studies of the self-assembly of heterogeneous colloidal systems</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Teich-McGoldrick, Stephanie Leah</p> <p></p> <p> extension of NMA to finite temperature systems was developed without having to couple to slower simulations. Using the Lennard-Jones <span class="hlt">model</span>, kinetic energy was introduced into the system by randomly displacing particles in a crystal. Temperature was related to these displacements through the equipartition theorem. Upon comparison with published work on the Lennard-Jones spinodal, we determined that NMA reasonably predicts the limit of mechanical stability at low temperatures, but overestimates it at higher temperatures.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/19940017858','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19940017858"><span id="translatedtitle"><span class="hlt">Mesoscale</span> simulations of the November 25-26 and December 5-6 cirrus cases using the RAMS <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>Harrington, J. L.; Meyers, Michael P.; Cotton, William R.</p> <p>1993-01-01</p> <p>The Regional Atmospheric <span class="hlt">Modeling</span> System (RAMS), developed at Colorado State University, was used during the First ISCCP (International Satellite Cloud Climatology Project) Regional Experiment (FIRE) 2 (13 Nov. through 6 Dec. 1991) to provide real time forecasts of cirrus clouds. Forecasts were run once a day, initializing with the 0000 UTC dataset provided by NOAA (Forecast Systems Laboratory (FSL) <span class="hlt">Mesoscale</span> Analysis and Prediction System (MAPS)). In order to obtain better agreement with observations, a second set of simulations were done for the FIRE 2 cases that occurred on 25-26 Nov. and 5-6 Dec. In this set of simulations, a more complex radiation scheme was used, the Chen/Cotton radiation scheme, along with the nucleation of ice occurring at ice supersaturations as opposed to nucleation occurring at water supersaturations that was done in the actual forecast version. The runs using these more complex schemes took longer wall clock time (7-9 hours for the actual forecasts as compared to 12-14 hrs for the runs using the more complex schemes) however, the final results of the simulations were definitely improved upon. Comparisons between these two sets of simulations are given. Now underway are simulations of these cases using a closed analytical solution for the auto-conversion of ice from a pristine ice class (sizes less than about 50 microns in effective diameter) to a snow class (effective diameters on the order of several hundred microns). This solution is employed along with a new scheme for the nucleation of ice crystals due to Meyers et al and Demott et al. The scheme is derived assuming complete gamma distributions for both the pristine and snow classes. The time rate of change of the number concentration and mass mixing-ratio of each distribution is found by calculating either the flux of crystals that grow beyond a certain critical diameter by vapor deposition in an ice supersaturated regime or by calculating the flux of crystals that evaporate to</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016BoLMe.159..495S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016BoLMe.159..495S"><span id="translatedtitle">A <span class="hlt">Mesoscale</span> <span class="hlt">Model</span>-Based Climatography of Nocturnal Boundary-Layer Characteristics over the Complex Terrain of North-Western Utah</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Serafin, Stefano; De Wekker, Stephan F. J.; Knievel, Jason C.</p> <p>2016-06-01</p> <p>Nocturnal boundary-layer phenomena in regions of complex topography are extremely diverse and respond to a multiplicity of forcing factors, acting primarily at the <span class="hlt">mesoscale</span> and microscale. The interaction between different physical processes, e.g., drainage promoted by near-surface cooling and ambient flow over topography in a statically stable environment, may give rise to special flow patterns, uncommon over flat terrain. Here we present a climatography of boundary-layer flows, based on a 2-year archive of simulations from a high-resolution operational <span class="hlt">mesoscale</span> weather <span class="hlt">modelling</span> system, 4DWX. The geographical context is Dugway Proving Ground, in north-western Utah, USA, target area of the field campaigns of the MATERHORN (Mountain Terrain Atmospheric <span class="hlt">Modeling</span> and Observations Program) project. The comparison between <span class="hlt">model</span> fields and available observations in 2012-2014 shows that the 4DWX <span class="hlt">model</span> system provides a realistic representation of wind speed and direction in the area, at least in an average sense. Regions displaying strong spatial gradients in the field variables, thought to be responsible for enhanced nocturnal mixing, are typically located in transition areas from mountain sidewalls to adjacent plains. A key dynamical process in this respect is the separation of dynamically accelerated downslope flows from the surface.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015EGUGA..1714456C','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015EGUGA..1714456C"><span id="translatedtitle">Study strong wind events with erosional effect at coastal areas in Southern Italy comparing SAR vs METMAST vs High Resolution <span class="hlt">Mesoscale</span> <span class="hlt">Model</span> Output</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Calaudi, Rosamaria; Avolio, Elenio; Gullì, Daniel; Lo Feudo, Teresa; Calidonna, Claudia</p> <p>2015-04-01</p> <p>This study focus on evaluating the use of Synthetic Aperture Radar (SAR) together with experimental data, and output of High Resolution <span class="hlt">Mesoscale</span> <span class="hlt">Model</span> for evaluation of coastal erosional effect in Southern Mediterranean areas, where spatial wind information is only provided by sparse buoys, often with long periods of missing data. Since in Mediterranean seas there are limited offshore experimental data, we have performed a qualitative analysis of satellite observations comparing SAR with the available experimental data from the Calabrian Regional Environmental Protection Agency (Functional Multirisk Center) for the case study of Lamezia Terme for the period of 2011-2012. Wind climate for the coastal waters off South Italy were made based on images from March 2002 to April 2012 of the Advanced Synthetic Aperture Radar (ASAR) onboard the ENVISAT satellite. Wind speed fields were derived from the SAR images using the Johns Hopkins University, Applied Physics Laboratory (JHU/APL) software APL/NOAA SAR Wind Retrieval System (ANSWRS version 2.0) with the geophysical <span class="hlt">model</span> function CMOD5.N. Mean wind speed and energy density were estimated using the Weibull distribution function. This new technique is seen as a supplement to classical wind sampling and <span class="hlt">modelling</span> efforts, not as a stand-alone alternative. Some evidence on test cases of wind storm, in the considered region, will be described regarding some events happened in winter 2011-2012 comparing data from SAR, Metmast and Output of High Resolution <span class="hlt">Mesoscale</span> <span class="hlt">Model</span>.</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://www.osti.gov/scitech/servlets/purl/992747','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/servlets/purl/992747"><span id="translatedtitle">Implementation and assessment of turbine wake <span class="hlt">models</span> in the Weather Research and Forecasting <span class="hlt">model</span> for both <span class="hlt">mesoscale</span> and large-eddy simulation</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Singer, M; Mirocha, J; Lundquist, J; Cleve, J</p> <p>2010-03-03</p> <p>Flow dynamics in large wind projects are influenced by the turbines located within. The turbine wakes, regions characterized by lower wind speeds and higher levels of turbulence than the surrounding free stream flow, can extend several rotor diameters downstream, and may meander and widen with increasing distance from the turbine. Turbine wakes can also reduce the power generated by downstream turbines and accelerate fatigue and damage to turbine components. An improved understanding of wake formation and transport within wind parks is essential for maximizing power output and increasing turbine lifespan. Moreover, the influence of wakes from large wind projects on neighboring wind farms, agricultural activities, and local climate are all areas of concern that can likewise be addressed by wake <span class="hlt">modeling</span>. This work describes the formulation and application of an actuator disk <span class="hlt">model</span> for studying flow dynamics of both individual turbines and arrays of turbines within wind projects. The actuator disk <span class="hlt">model</span> is implemented in the Weather Research and Forecasting (WRF) <span class="hlt">model</span>, which is an open-source atmospheric simulation code applicable to a wide range of scales, from <span class="hlt">mesoscale</span> to large-eddy simulation. Preliminary results demonstrate the applicability of the actuator disk <span class="hlt">model</span> within WRF to a moderately high-resolution large-eddy simulation study of a small array of turbines.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://ntrs.nasa.gov/search.jsp?R=20080030357&hterms=Hurricane+Katrina&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D10%26Ntt%3D%2528Hurricane%2BKatrina%2529','NASA-TRS'); return false;" href="http://ntrs.nasa.gov/search.jsp?R=20080030357&hterms=Hurricane+Katrina&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D10%26Ntt%3D%2528Hurricane%2BKatrina%2529"><span id="translatedtitle">The Impact of Microphysics on Intensity and Structure of Hurricanes and <span class="hlt">Mesoscale</span> Convective Systems</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; Shi, Jainn J.; Jou, Ben Jong-Dao; Lee, Wen-Chau; Lin, Pay-Liam; Chang, Mei-Yu</p> <p>2007-01-01</p> <p>During the past decade, both research and operational numerical weather prediction <span class="hlt">models</span>, e.g. Weather Research and Forecast (WRF) <span class="hlt">model</span>, have started using more complex microphysical schemes originally developed for high-resolution cloud resolving <span class="hlt">models</span> (CRMs) with a 1-2 km or less horizontal resolutions. WRF is a next-generation <span class="hlt">mesoscale</span> forecast <span class="hlt">model</span> and assimilation system that has incorporated modern software framework, advanced dynamics, numeric and data assimilation techniques, a multiple moveable <span class="hlt">nesting</span> capability, and improved physical packages. WRF <span class="hlt">model</span> can be used for a wide range of applications, from idealized research to operational forecasting, with an emphasis on horizontal grid sizes in the range of 1-10 km. The current WRF includes several different microphysics options such as Purdue Lin et al. (1983), WSM 6-class and Thompson microphysics schemes. We have recently implemented three sophisticated cloud microphysics schemes into WRF. The cloud microphysics schemes have been extensively tested and applied for different <span class="hlt">mesoscale</span> systems in different geographical locations. The performances of these schemes have been compared to those from other WRF microphysics options. We are performing sensitivity tests in using WRF to examine the impact of six different cloud microphysical schemes on precipitation processes associated hurricanes and <span class="hlt">mesoscale</span> convective systems developed at different geographic locations [Oklahoma (IHOP), Louisiana (Hurricane Katrina), Canada (C3VP - snow events), Washington (fire storm), India (Monsoon), Taiwan (TiMREX - terrain)]. We will determine the microphysical schemes for good simulated convective systems in these geographic locations. We are also performing the inline tracer calculation to comprehend the physical processes (i.e., boundary layer and each quadrant in the boundary layer) related to the development and structure of hurricanes and <span class="hlt">mesoscale</span> convective systems.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015AIPC.1641..121H','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015AIPC.1641..121H"><span id="translatedtitle"><span class="hlt">Nested</span> sampling with demons</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Habeck, Michael</p> <p>2015-01-01</p> <p>This article looks at Skilling's <span class="hlt">nested</span> sampling from a physical perspective and interprets it as a microcanonical demon algorithm. Using key quantities of statistical physics we investigate the performance of <span class="hlt">nested</span> sampling on complex systems such as Ising, Potts and protein <span class="hlt">models</span>. We show that releasing multiple demons helps to smooth the truncated prior and eases sampling from it because the demons keep the particle off the constraint boundary. For continuous systems it is straightforward to extend this approach and formulate a phase space version of <span class="hlt">nested</span> sampling that benefits from correlated explorations guided by Hamiltonian dynamics.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://ntrs.nasa.gov/search.jsp?R=20060013030&hterms=degree+day&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D30%26Ntt%3D%2528degree%2Bday%2529','NASA-TRS'); return false;" href="http://ntrs.nasa.gov/search.jsp?R=20060013030&hterms=degree+day&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D30%26Ntt%3D%2528degree%2Bday%2529"><span id="translatedtitle">The 0.125 degree finite-volume General Circulation <span class="hlt">Model</span> on the NASA Columbia Supercomputer: Preliminary Simulations of <span class="hlt">Mesoscale</span> Vortices</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.; Atlas, R.; Chern, J.-D.; Reale, O.; Lin, S.-J.; Lee, T.; Chang, J.</p> <p>2005-01-01</p> <p>The NASA Columbia supercomputer was ranked second on the TOP500 List in November, 2004. Such a quantum jump in computing power provides unprecedented opportunities to conduct ultra-high resolution simulations with the finite-volume General Circulation <span class="hlt">Model</span> (fvGCM). During 2004, the <span class="hlt">model</span> was run in realtime experimentally at 0.25 degree resolution producing remarkable hurricane forecasts [Atlas et al., 2005]. In 2005, the horizontal resolution was further doubled, which makes the fvGCM comparable to the first <span class="hlt">mesoscale</span> resolving General Circulation <span class="hlt">Model</span> at the Earth Simulator Center [Ohfuchi et al., 2004]. Nine 5-day 0.125 degree simulations of three hurricanes in 2004 are presented first for <span class="hlt">model</span> validation. Then it is shown how the <span class="hlt">model</span> can simulate the formation of the Catalina eddies and Hawaiian lee vortices, which are generated by the interaction of the synoptic-scale flow with surface forcing, and have never been reproduced in a GCM before.)</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015EGUGA..17.9941B','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015EGUGA..17.9941B"><span id="translatedtitle">Quantifying the effects of boundary condition uncertainty in <span class="hlt">nested</span> flood <span class="hlt">modelling</span> of complex hydraulic systems</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Bermudez, Maria; Neal, Jeffrey C.; Bates, Paul D.; Coxon, Gemma; Freer, Jim E.; Cea, Luis; Puertas, Jeronimo</p> <p>2015-04-01</p> <p> through the city of Worcester (West Midlands, England), a flat subcritical reach in which backwater effects are significant. The flood event selected as a case study took place on the 20th July 2007 and is part of a series of destructive floods that occurred in the United Kingdom during that summer season. A full two-dimensional hydraulic <span class="hlt">model</span> with a high resolution grid is adopted at the local scale to resolve the complex urban flow field within Worcester, whereas a simpler representation of the flow processes that ignores convective acceleration has been selected for the regional <span class="hlt">model</span>. This <span class="hlt">nested</span> <span class="hlt">modelling</span> approach hence allows a continuous examination of the water fluxes from the catchment scale down to the reach and building scale, while still requiring reduced setup time and computational demand. Differences with measured water levels at benchmark stations and with flood extent from SAR images are used to evaluate the resulting prediction uncertainties. The results quantify how external forcing uncertainty propagates through flood inundation <span class="hlt">models</span> and affects <span class="hlt">model</span> predictions. This allows us to compare the relative importance of this uncertainty, often neglected in flood <span class="hlt">modelling</span>, with that of <span class="hlt">model</span> parameters.</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=1692696','PMC'); return false;" href="http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=1692696"><span id="translatedtitle">Parsimonious <span class="hlt">modelling</span> of water and suspended sediment flux from <span class="hlt">nested</span> catchments affected by selective tropical forestry.</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Chappell, N A; McKenna, P; Bidin, K; Douglas, I; Walsh, R P</p> <p>1999-01-01</p> <p>The ability to <span class="hlt">model</span> the suspended sediment flux (SSflux) and associated water flow from terrain affected by selective logging is important to the establishment of credible measures to improve the ecological sustainability of forestry practices. Recent appreciation of the impact of parameter uncertainty on the statistical credibility of complex <span class="hlt">models</span> with little internal state validation supports the use of more parsimonious approaches such as data-based mechanistic (DBM) <span class="hlt">modelling</span>. The DBM approach combines physically based understanding with <span class="hlt">model</span> structure identification based on transfer functions and objective statistical inference. Within this study, these approaches have been newly applied to rainfall-SSflux response. The dynamics of the sediment system, together with the rainfall-river flow system, were monitored at five <span class="hlt">nested</span> contributory areas within a 44 ha headwater region in Malaysian Borneo. The data series analysed covered a whole year at a 5 min resolution, and were collected during a period some five to six years after selective timber harvesting had ceased. Physically based and statistical interpretation of these data was possible given the wealth of contemporary and past hydrogeomorphic data collected within the same region. The results indicated that parsimonious, three-parameter <span class="hlt">models</span> of rainfall-river flow and rainfall-SSflux for the whole catchment describe 80 and 90% of the variance, respectively, and that parameter changes between scales could be explained in physically meaningful terms. Indeed, the <span class="hlt">modelling</span> indicated some new conceptual descriptions of the river flow and sediment-generation systems. An extreme rainstorm having a 10-20 year return period was present within the data series and was shown to generate new mass movements along the forestry roads that had a differential impact on the monitored contributory areas. Critically, this spatially discrete behaviour was captured by the <span class="hlt">modelling</span> and may indicate the potential use of</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015AtmRe.154..175L','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015AtmRe.154..175L"><span id="translatedtitle">Hybrid fine scale climatology and microphysics of in-cloud icing: From 32 km reanalysis to 5 km <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>Lamraoui, Fayçal; Benoit, Robert; Perron, Jean; Fortin, Guy; Masson, Christian</p> <p>2015-03-01</p> <p>In-cloud icing can impose safety concerns and economic challenges for various industries. Icing climate representations proved beneficial for optimal designs and careful planning. The current study investigates in-cloud icing, its related cloud microphysics and introduces a 15-year time period climatology of icing events. The <span class="hlt">model</span> was initially driven by reanalysis data from North American Regional Reanalysis and downscaled through a two-level <span class="hlt">nesting</span> of 10 km and 5 km, using a limited-area version of the Global Environment Multiscale <span class="hlt">Model</span> of the Canadian Meteorological Center. In addition, a hybrid approach is used to reduce time consuming calculations. The simulation realized exclusively on significant icing days, was combined with non-significant icing days as represented by data from NARR. A proof of concept is presented here for a 1000 km area around Gaspé during January for those 15 years. An increase in the number and intensity of icing events has been identified during the last 15 years. From GEM-LAM simulations and within the atmospheric layer between 10 m and 200 m AGL, supercooled liquid water contents indicated a maximum of 0.4 g m- 3, and 50% of the values are less than 0.05 g m- 3. All values of median volume diameters (MVD) are approximately capped by 70 μm and the typical values are around 15 μm. Supercooled Large Droplets represent approximately 5%. The vertical profile of icing climatology demonstrates a steady duration of icing events until the level of 60 m. The altitudes of 60 m and 100 m indicate substantial icing intensification toward higher elevations. GEM-LAM demonstrated a substantial improvement in the calculation of in-cloud icing, reducing significantly the challenge posed by complex terrains.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014AGUFMGC13J0812F','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014AGUFMGC13J0812F"><span id="translatedtitle">Assessing Climatic Impacts due to Land Use Change over Southeast Asian Maritime Continent base on <span class="hlt">Mesoscale</span> <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>Feng, N.; Christopher, S. A.; Nair, U. S.</p> <p>2014-12-01</p> <p>Due to increasing urbanization, deforestation, and agriculture, land use change over Southeast Asia has dramatically risen during the last decades. Large areas of peat swamp forests over the Southeast Asian Maritime Continent region (10°S~20°N and 90°E~135°E) have been cleared for agricultural purposes. The Center for Remote Imaging, Sensing and Processing (CRISP) Moderate Resolution Imaging Spectroradiometer (MODIS) derived land cover classification data show that changes in land use are dominated by conversion of peat swamp forests to oil palm plantation, open lowland or lowland mosaic categories. <span class="hlt">Nested</span> grid simulations based on Weather Research Forecasting Version 3.6 <span class="hlt">modelling</span> system (WRFV3.6) over the central region of the Sarawak coast are used to investigate the climatic impacts of land use change over Maritime Continent. Numerical simulations were conducted for August of 2009 for satellite derived land cover scenarios for years 2000 and 2010. The variations in cloud formation, precipitation, and regional radiative and non-radiative parameters on climate results from land use change have been assessed based on numerical simulation results. <span class="hlt">Modelling</span> studies demonstrate that land use change such as extensive deforestation processes can produce a negative radiative forcing due to the surface albedo increase and evapotranspiration decrease, while also largely caused reduced rainfall and cloud formation, and enhanced shortwave radiative forcing and temperature over the study area. Land use and land cover changes, similar to the domain in this study, has also occurred over other regions in Southeast Asia including Indonesia and could also impact cloud and precipitation formation in these regions.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2011OcDyn..61.1937H','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2011OcDyn..61.1937H"><span id="translatedtitle">Development and testing of a coupled ocean-atmosphere <span class="hlt">mesoscale</span> ensemble prediction system</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Holt, Teddy R.; Cummings, James A.; Bishop, Craig H.; Doyle, James D.; Hong, Xiaodong; Chen, Sue; Jin, Yi</p> <p>2011-11-01</p> <p>A coupled ocean-atmosphere <span class="hlt">mesoscale</span> ensemble prediction system has been developed by the Naval Research Laboratory. This paper describes the components and implementation of the system and presents baseline results from coupled ensemble simulations for two tropical cyclones. The system is designed to take into account major sources of uncertainty in: (1) non-deterministic dynamics, (2) <span class="hlt">model</span> error, and (3) initial states. The purpose of the system is to provide <span class="hlt">mesoscale</span> ensemble forecasts for use in probabilistic products, such as reliability and frequency of occurrence, and in risk management applications. The system components include COAMPS® (Coupled Ocean/Atmosphere <span class="hlt">Mesoscale</span> Prediction System) and NCOM (Navy Coastal Ocean <span class="hlt">Model</span>) for atmosphere and ocean forecasting and NAVDAS (NRL Atmospheric Variational Data Assimilation System) and NCODA (Navy Coupled Ocean Data Assimilation) for atmosphere and ocean data assimilation. NAVDAS and NCODA are 3D-variational (3DVAR) analysis schemes. The ensembles are generated using separate applications of the Ensemble Transform (ET) technique in both the atmosphere (for moving or non-moving <span class="hlt">nests</span>) and the ocean. The atmospheric ET is computed using wind, temperature, and moisture variables, while the oceanographic ET is derived from ocean current, temperature, and salinity variables. Estimates of analysis error covariance, which is used as a constraint in the ET, are provided by the ocean and atmosphere 3DVAR assimilation systems. The newly developed system has been successfully tested for a variety of configurations, including differing <span class="hlt">model</span> resolution, number of members, forecast length, and moving and fixed <span class="hlt">nest</span> options. Results from relatively coarse resolution (˜27-km) ensemble simulations of Hurricanes Hanna and Ike demonstrate that the ensemble can provide valuable uncertainty information about the storm track and intensity, though the ensemble mean provides only a small amount of improved predictive skill</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015EGUGA..1711564C','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015EGUGA..1711564C"><span id="translatedtitle">The Mediterranean overflow: New insights and numerical sensitivity from multiply <span class="hlt">nested</span> <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>Chanut, Jérôme; Benshila, Rachid; Debreu, Laurent; Masson, Sébastien</p> <p>2015-04-01</p> <p>In the past 20 years, ocean <span class="hlt">modellers</span> have paid much attention to either Gibraltar strait dynamics or Meddies formation, which are respectively at the origin and the end of the Mediterranean overflow descent in the Atlantic Ocean. Although the importance of topography is acknowledged on what happens in between, (i) the finest resolution in existing <span class="hlt">modelling</span> studies is still too coarse (o 2-6km) to properly capture main channels and canyons; (ii) results convergence relative to numerical settings has remained largely unexplored. Recent progress in the knowledge of the geological properties of the Gulf of Cadiz has indeed revealed the ubiquity of small scales bathymetry structures (o 1km) and a complex system of channels shaped by the Mediterranean Overflow (MO) currents. Taking advantage of a new high resolution bathymetry dataset, we present a refined view of MO splitting and spreading from semi-idealized numerical simulations. A multi grid, two-way <span class="hlt">nested</span> procedure is used to increase the horizontal resolution in key areas up to 250m, revealing the channelizing effect of bathymetry and the localized nature of mixing along MO pathways. The impact of vertical coordinate choice is investigated thanks to NEMO generalized vertical coordinate framework. The combination of geopotential and terrain following coordinates is shown to be the best compromise to faithfully represent the steep slopes bordering the basin, minimize pressure gradient errors and properly resolve bottom layers. Results with z-coordinates, as expected, perform relatively poorly leading to excessive entrainment. Sensitivity to vertical mixing schemes as well as horizontal resolution is also explored, providing an extensive set of experiments that complements similar studies in other overflow regions.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2009AGUFM.H33E0917H','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2009AGUFM.H33E0917H"><span id="translatedtitle">Assessment of <span class="hlt">Mesoscale</span> Dynamical Downscaling <span class="hlt">Model</span> (MM5) for Regional Climate Simulation in the Tampa Bay region</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Hwang, S.; Graham, W. D.; Hernandez, J.; Martinez, C. J.; Jones, J. W.</p> <p>2009-12-01</p> <p>This research analyzes the temporal and spatial variability of historic precipitation in Tampa Bay region and evaluates the ability of the <span class="hlt">mesoscale</span> downscaling <span class="hlt">model</span> (MM5, Grell et al., 1994), to reproduce this variability. The long term goal of this effort is to evaluate the utility of using MM5 to downscale GCM forecasts and climate change scenarios for improving water management decisions in the Tampa Bay region. Cumulative probability distributions were constructed using observed daily and monthly rainfall at each station, and the spatial correlations between the 53 stations were analyzed for each month using covariance and variogram analysis for both observed data and MM5 predictions. MM5 was run to predict precipitation at 9x9 and 27x27 km2 spatial resolutions and 6-hour temporal resolution over the 23 year period from 1986 to 2008 using the NCEP/NCAR reanalysis data set as initial and boundary conditions. The raw precipitation predictions were then bias-corrected at each observation station using the cumulative probability distribution mapping approach (Wood et al., 2002). Daily and monthly precipitation totals were estimated over the Alafia and Hillsborough River watersheds using the bias-corrected point precipitation and observed variogram functions. MM5 performance was assessed by cross-validating predicted daily and monthly point and total watershed precipitation for each month. Variograms from the bias-corrected daily precipitation predictions in general indicated that MM5 overestimates the strength of the spatial correlation and underestimates the variance of precipitation compared to the observed data, especially in the summer months when convective storms dominate. The simulations for each month reproduced the daily mean point precipitation values with an average error of -0.0641 in (Jul.) to 0.0214 in (Oct.) with an average RMSE of 0.6834 in (Mar.) to 0.9449 in (Sep.) over the 53 rain stations. Monthly mean point precipitation values were</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2012AIPC.1450..147W','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2012AIPC.1450..147W"><span id="translatedtitle"><span class="hlt">Nested</span> generalized linear mixed <span class="hlt">model</span> with ordinal response: Simulation and application on poverty data in Java Island</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Widyaningsih, Yekti; Saefuddin, Asep; Notodiputro, Khairil A.; Wigena, Aji H.</p> <p>2012-05-01</p> <p>The objective of this research is to build a <span class="hlt">nested</span> generalized linear mixed <span class="hlt">model</span> using an ordinal response variable with some covariates. There are three main jobs in this paper, i.e. parameters estimation procedure, simulation, and implementation of the <span class="hlt">model</span> for the real data. At the part of parameters estimation procedure, concepts of threshold, <span class="hlt">nested</span> random effect, and computational algorithm are described. The simulations data are built for 3 conditions to know the effect of different parameter values of random effect distributions. The last job is the implementation of the <span class="hlt">model</span> for the data about poverty in 9 districts of Java Island. The districts are Kuningan, Karawang, and Majalengka chose randomly in West Java; Temanggung, Boyolali, and Cilacap from Central Java; and Blitar, Ngawi, and Jember from East Java. The covariates in this <span class="hlt">model</span> are province, number of bad nutrition cases, number of farmer families, and number of health personnel. In this <span class="hlt">modeling</span>, all covariates are grouped as ordinal scale. Unit observation in this research is sub-district (kecamatan) <span class="hlt">nested</span> in district, and districts (kabupaten) are <span class="hlt">nested</span> in province. For the result of simulation, ARB (Absolute Relative Bias) and RRMSE (Relative Root of mean square errors) scale is used. They show that prov parameters have the highest bias, but more stable RRMSE in all conditions. The simulation design needs to be improved by adding other condition, such as higher correlation between covariates. Furthermore, as the result of the <span class="hlt">model</span> implementation for the data, only number of farmer family and number of medical personnel have significant contributions to the level of poverty in Central Java and East Java province, and only district 2 (Karawang) of province 1 (West Java) has different random effect from the others. The source of the data is PODES (Potensi Desa) 2008 from BPS (Badan Pusat Statistik).</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/24815341','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/24815341"><span id="translatedtitle">Spatial analysis of toxic emissions in LCA: a sub-continental <span class="hlt">nested</span> USEtox <span class="hlt">model</span> with freshwater archetypes.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Kounina, Anna; Margni, Manuele; Shaked, Shanna; Bulle, Cécile; Jolliet, Olivier</p> <p>2014-08-01</p> <p>This paper develops continent-specific factors for the USEtox <span class="hlt">model</span> and analyses the accuracy of different <span class="hlt">model</span> architectures, spatial scales and archetypes in evaluating toxic impacts, with a focus on freshwater pathways. Inter-continental variation is analysed by comparing chemical fate and intake fractions between sub-continental zones of two life cycle impact assessment <span class="hlt">models</span>: (1) the <span class="hlt">nested</span> USEtox <span class="hlt">model</span> parameterized with sub-continental zones and (2) the spatially differentiated IMPACTWorld <span class="hlt">model</span> with 17 interconnected sub-continental regions. Substance residence time in water varies by up to two orders of magnitude among the 17 zones assessed with IMPACTWorld and USEtox, and intake fraction varies by up to three orders of magnitude. Despite this variation, the <span class="hlt">nested</span> USEtox <span class="hlt">model</span> succeeds in mimicking the results of the spatially differentiated <span class="hlt">model</span>, with the exception of very persistent volatile pollutants that can be transported to polar regions. Intra-continental variation is analysed by comparing fate and intake fractions <span class="hlt">modelled</span> with the a-spatial (one box) IMPACT Europe continental <span class="hlt">model</span> vs. the spatially differentiated version of the same <span class="hlt">model</span>. Results show that the one box <span class="hlt">model</span> might overestimate chemical fate and characterisation factors for freshwater eco-toxicity of persistent pollutants by up to three orders of magnitude for point source emissions. Subdividing Europe into three archetypes, based on freshwater residence time (how long it takes water to reach the sea), improves the prediction of fate and intake fractions for point source emissions, bringing them within a factor five compared to the spatial <span class="hlt">model</span>. We demonstrated that a sub-continental <span class="hlt">nested</span> <span class="hlt">model</span> such as USEtox, with continent-specific parameterization complemented with freshwater archetypes, can thus represent inter- and intra-continental spatial variations, whilst minimizing <span class="hlt">model</span> complexity. PMID:24815341</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://files.eric.ed.gov/fulltext/ED551064.pdf','ERIC'); return false;" href="http://files.eric.ed.gov/fulltext/ED551064.pdf"><span id="translatedtitle">A Primer for Analyzing <span class="hlt">Nested</span> Data: Multilevel <span class="hlt">Modeling</span> in SPSS Using an Example from a REL Study. REL 2015-046</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>O'Dwyer, Laura M.; Parker, Caroline E.</p> <p>2014-01-01</p> <p>Analyzing data that possess some form of <span class="hlt">nesting</span> is often challenging for applied researchers or district staff who are involved in or in charge of conducting data analyses. This report provides a description of the challenges for analyzing <span class="hlt">nested</span> data and provides a primer of how multilevel regression <span class="hlt">modeling</span> may be used to resolve these…</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/25607302','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/25607302"><span id="translatedtitle"><span class="hlt">Mesoscale</span> <span class="hlt">modeling</span> of photoelectrochemical devices: light absorption and carrier collection in monolithic, tandem, Si|WO3 microwires.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Fountaine, Katherine T; Atwater, Harry A</p> <p>2014-10-20</p> <p>We analyze <span class="hlt">mesoscale</span> light absorption and carrier collection in a tandem junction photoelectrochemical device using electromagnetic simulations. The tandem device consists of silicon (E(g,Si) = 1.1 eV) and tungsten oxide (E(g,WO3) = 2.6 eV) as photocathode and photoanode materials, respectively. Specifically, we investigated Si microwires with lengths of 100 µm, and diameters of 2 µm, with a 7 µm pitch, covered vertically with 50 µm of WO3 with a thickness of 1 µm. Many geometrical variants of this prototypical tandem device were explored. For conditions of illumination with the AM 1.5G spectra, the nominal design resulted in a short circuit current density, J(SC), of 1 mA/cm(2), which is limited by the WO3 absorption. Geometrical optimization of photoanode and photocathode shape and contact material selection, enabled a three-fold increase in short circuit current density relative to the initial design via enhanced WO3 light absorption. These findings validate the usefulness of a <span class="hlt">mesoscale</span> analysis for ascertaining optimum optoelectronic performance in photoelectrochemical devices.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4438871','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4438871"><span id="translatedtitle">Evaluation of Trail-Cameras for Analyzing the Diet of <span class="hlt">Nesting</span> Raptors Using the Northern Goshawk as a <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>García-Salgado, Gonzalo; Rebollo, Salvador; Pérez-Camacho, Lorenzo; Martínez-Hesterkamp, Sara; Navarro, Alberto; Fernández-Pereira, José-Manuel</p> <p>2015-01-01</p> <p>Diet studies present numerous methodological challenges. We evaluated the usefulness of commercially available trail-cameras for analyzing the diet of Northern Goshawks (Accipiter gentilis) as a <span class="hlt">model</span> for <span class="hlt">nesting</span> raptors during the period 2007–2011. We compared diet estimates obtained by direct camera monitoring of 80 <span class="hlt">nests</span> with four indirect analyses of prey remains collected from the <span class="hlt">nests</span> and surroundings (pellets, bones, feather-and-hair remains, and feather-hair-and-bone remains combined). In addition, we evaluated the performance of the trail-cameras and whether camera monitoring affected Goshawk behavior. The sensitivity of each diet-analysis method depended on prey size and taxonomic group, with no method providing unbiased estimates for all prey sizes and types. The cameras registered the greatest number of prey items and were probably the least biased method for estimating diet composition. Nevertheless this direct method yielded the largest proportion of prey unidentified to species level, and it underestimated small prey. Our trail-camera system was able to operate without maintenance for longer periods than what has been reported in previous studies with other types of cameras. Initially Goshawks showed distrust toward the cameras but they usually became habituated to its presence within 1–2 days. The habituation period was shorter for breeding pairs that had previous experience with cameras. Using trail-cameras to monitor prey provisioning to <span class="hlt">nests</span> is an effective tool for studying the diet of <span class="hlt">nesting</span> raptors. However, the technique is limited by technical failures and difficulties in identifying certain prey types. Our study also shows that cameras can alter adult Goshawk behavior, an aspect that must be controlled to minimize potential negative impacts. PMID:25992956</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/25992956','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/25992956"><span id="translatedtitle">Evaluation of trail-cameras for analyzing the diet of <span class="hlt">nesting</span> raptors using the Northern Goshawk as a <span class="hlt">model</span>.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>García-Salgado, Gonzalo; Rebollo, Salvador; Pérez-Camacho, Lorenzo; Martínez-Hesterkamp, Sara; Navarro, Alberto; Fernández-Pereira, José-Manuel</p> <p>2015-01-01</p> <p>Diet studies present numerous methodological challenges. We evaluated the usefulness of commercially available trail-cameras for analyzing the diet of Northern Goshawks (Accipiter gentilis) as a <span class="hlt">model</span> for <span class="hlt">nesting</span> raptors during the period 2007-2011. We compared diet estimates obtained by direct camera monitoring of 80 <span class="hlt">nests</span> with four indirect analyses of prey remains collected from the <span class="hlt">nests</span> and surroundings (pellets, bones, feather-and-hair remains, and feather-hair-and-bone remains combined). In addition, we evaluated the performance of the trail-cameras and whether camera monitoring affected Goshawk behavior. The sensitivity of each diet-analysis method depended on prey size and taxonomic group, with no method providing unbiased estimates for all prey sizes and types. The cameras registered the greatest number of prey items and were probably the least biased method for estimating diet composition. Nevertheless this direct method yielded the largest proportion of prey unidentified to species level, and it underestimated small prey. Our trail-camera system was able to operate without maintenance for longer periods than what has been reported in previous studies with other types of cameras. Initially Goshawks showed distrust toward the cameras but they usually became habituated to its presence within 1-2 days. The habituation period was shorter for breeding pairs that had previous experience with cameras. Using trail-cameras to monitor prey provisioning to <span class="hlt">nests</span> is an effective tool for studying the diet of <span class="hlt">nesting</span> raptors. However, the technique is limited by technical failures and difficulties in identifying certain prey types. Our study also shows that cameras can alter adult Goshawk behavior, an aspect that must be controlled to minimize potential negative impacts. PMID:25992956</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://ntrs.nasa.gov/search.jsp?R=19940007285&hterms=zones+ocean&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D90%26Ntt%3Dzones%2Bocean','NASA-TRS'); return false;" href="http://ntrs.nasa.gov/search.jsp?R=19940007285&hterms=zones+ocean&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D90%26Ntt%3Dzones%2Bocean"><span id="translatedtitle">Waves and <span class="hlt">mesoscale</span> features in the marginal ice zone</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Liu, Antony K.; Peng, Chih Y.</p> <p>1993-01-01</p> <p>Ocean-ice interaction processes in the Marginal Ice Zone (MIZ) by waves and <span class="hlt">mesoscale</span> features, such as upwelling and eddies, are studied using ERS-1 Synthetic Aperture Radar (SAR) imagery and wave-ice interaction <span class="hlt">models</span>. Satellite observations of <span class="hlt">mesoscale</span> features can play a crucial role in ocean-ice interaction study.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=2864735','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=2864735"><span id="translatedtitle">3-D <span class="hlt">Modelling</span> of Megaloolithid Clutches: Insights about <span class="hlt">Nest</span> Construction and Dinosaur Behaviour</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Vila, Bernat; Jackson, Frankie D.; Fortuny, Josep; Sellés, Albert G.; Galobart, Àngel</p> <p>2010-01-01</p> <p>Background Megaloolithid eggs have long been associated with sauropod dinosaurs. Despite their extensive and worldwide fossil record, interpretations of egg size and shape, clutch morphology, and incubation strategy vary. The Pinyes locality in the Upper Cretaceous Tremp Formation in the southern Pyrenees, Catalonia provides new information for addressing these issues. Nine horizons containing Megaloolithus siruguei clutches are exposed near the village of Coll de Nargó. Tectonic deformation in the study area strongly influenced egg size and shape, which could potentially lead to misinterpretation of reproductive biology if 2D and 3D maps are not corrected for bed dip that results from tectonism. Methodology/Findings Detailed taphonomic study and three-dimensional <span class="hlt">modelling</span> of fossil eggs show that intact M. siruguei clutches contained 20–28 eggs, which is substantially larger than commonly reported from Europe and India. Linear and grouped eggs occur in three superimposed levels and form an asymmetric, elongate, bowl-shaped profile in lateral view. Computed tomography data support previous interpretations that the eggs hatched within the substrate. Megaloolithid clutch sizes reported from other European and Indian localities are typically less than 15 eggs; however, these clutches often include linear or grouped eggs that resemble those of the larger Pinyes clutches and may reflect preservation of incomplete clutches. Conclusions/Significance We propose that 25 eggs represent a typical megaloolithid clutch size and smaller egg clusters that display linear or grouped egg arrangements reported at Pinyes and other localities may represent eroded remnants of larger clutches. The similarity of megaloolithid clutch morphology from localities worldwide strongly suggests common reproductive behaviour. The distinct clutch geometry at Pinyes and other localities likely resulted from the asymmetrical, inclined, and laterally compressed titanosaur pes unguals of the female</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://eric.ed.gov/?q=SIC&pg=3&id=EJ554767','ERIC'); return false;" href="http://eric.ed.gov/?q=SIC&pg=3&id=EJ554767"><span id="translatedtitle"><span class="hlt">Model</span> Selection Information Criteria for Non-<span class="hlt">Nested</span> Latent Class <span class="hlt">Models</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>Lin, Ting Hsiang; Dayton, C. Mitchell</p> <p>1997-01-01</p> <p>The use of these three <span class="hlt">model</span> selection information criteria for latent class <span class="hlt">models</span> was studied for nonnested <span class="hlt">models</span>: (1) Akaike's information criterion (H. Akaike, 1973) (AIC); (2) the Schwarz information (G. Schwarz, 1978) (SIC) criterion; and (3) the Bozdogan version of the AIC (CAIC) (H. Bozdogan, 1987). Situations in which each is preferable…</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2009EGUGA..11.8571B&link_type=ABSTRACT','NASAADS'); return false;" href="http://adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2009EGUGA..11.8571B&link_type=ABSTRACT"><span id="translatedtitle"><span class="hlt">Modeling</span> the impact of tropical <span class="hlt">mesoscale</span> convective systems on Sahelian mineral dust budget: a case study during AMMA SOPs 1-2</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Bouet, C.; Cautenet, G.; Marticorena, B.; Bergametti, G.; Chatenet, B.; Rajot, J.-L.; Descroix, L.</p> <p>2009-04-01</p> <p>Tropical <span class="hlt">mesoscale</span> convective systems (MCSs) are a prominent feature of the African meteorology. A continuous monitoring of the aeolian activity in an experimental site located in Niger showed that such events are responsible for the major part of the annual local wind erosion, i.e. for most of the Sahelian dust emission [Rajot, 2001]. However, the net effect of these MCSs on mineral dust budget has to be estimated: on the one hand, these systems produce extremely high surface wind velocities leading to intense dust uptake, but on the other hand, rainfalls associated with these systems can efficiently remove the emitted dust from the atmosphere. High resolution <span class="hlt">modeling</span> of MCSs appears as the most relevant approach to assess the budget between dust emission and deposition in such local meteorological systems. As a first step, in order to properly estimate dust emissions, it is necessary to accurately describe the surface wind fields at the local scale. Indeed, dust emission is a threshold phenomenon that depends on the third power of surface wind velocity. This study focuses on a case study of dust emission associated with the passage of a MCS observed during one of the intensive observation period of the international African Monsoon Multidisciplinary Analysis (AMMA - SOPs 1-2) program. The simulations were made using the Regional Atmospheric <span class="hlt">Modeling</span> System (RAMS) coupled online with the dust production <span class="hlt">model</span> (DPM) developed by Marticorena and Bergametti [1995] and recently improved by Laurent et al. [2008] for Africa. Two horizontal resolutions were tested (5 km and 2.5 km) as well as two microphysical schemes (a 1-moment scheme [Walko et al., 1995] and a 2-moment scheme [Meyers et al., 1997]). The use of the two convective parameterizations now available in the version 6 of RAMS (Kuo [1995] modified by Molinari [1985] and Molinari and Corsetti [1985], and Kain and Fritsch [1992; 1993]) to simulate cloud convection was also tested. Sensitivity tests have been</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014AGUFMGC33A0495P','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014AGUFMGC33A0495P"><span id="translatedtitle">A 7-km Non-Hydrostatic Global <span class="hlt">Mesoscale</span> Simulation with the Goddard Earth Observing System <span class="hlt">Model</span> (GEOS-5) for Observing System Simulation Experiments</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Putman, W.; Suarez, M.; Gelaro, R.; daSilva, A.; Molod, A.; Ott, L. E.; Darmenov, A.</p> <p>2014-12-01</p> <p>The Global <span class="hlt">Modeling</span> and Assimilation Office at NASA Goddard Space Flight Center has used the Goddard Earth Observing System <span class="hlt">model</span> (GEOS-5) to produce a 2-year non-hydrostatic global <span class="hlt">mesoscale</span> simulation for the period of June 2005-2007. This 7-km GEOS-5 Nature Run (7km-G5NR) product will provide synthetic observations for observing system simulation experiments (OSSE)s at NASA and NOAA through the Joint Center for Satellite Data Assimilation and the NASA Center for Climate Simulation. While GEOS-5 is regularly applied in seasonal-to-decadal climate simulations, and medium range weather prediction and data assimilation, GEOS-5 is also readily adaptable for application as a global <span class="hlt">mesoscale</span> <span class="hlt">model</span> in pursuit of global cloud resolving applications. Recent computing advances have permitted experimentation with global atmospheric <span class="hlt">models</span> at these scales, although production applications like the 7km-G5NR have remained limited. By incorporating a non-hydrostatic finite-volume dynamical core with scale aware physics parameterizations, the 7km-G5NR produces organized convective systems and robust weather systems ideal for producing observations for existing and new remote sensing instruments. In addition to standard meteorological parameters, the 7km-G5NR includes 15 aerosol tracers (including dust, seasalt, sulfate, black and organic carbon), O3, CO and CO2. The 7km-G5NR is driven by prescribed sea-surface temperatures and sea-ice, daily volcanic and biomass burning emissions, as well as high-resolution inventories of anthropogenic sources. We will discuss the technical challenges of producing the 7km-G5NR including the nearly 5 petabytes of full resolution output at 30-minute intervals as required by the OSSE developers, and modifications to the standard GEOS-5 physics to permit convective organization at the 'grey-zone' resolution of 7km. Highlights of the 7km-G5NR validation will focus on the representation of clouds and organized convection including tropical cyclones</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016JPCS...96...22R','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016JPCS...96...22R"><span id="translatedtitle">Combined <span class="hlt">meso-scale</span> <span class="hlt">modeling</span> and experimental investigation of the effect of mechanical damage on the transport properties of cementitious composites</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Raghavan, Balaji; Niknezhad, Davood; Bernard, Fabrice; Kamali-Bernard, Siham</p> <p>2016-09-01</p> <p>The transport properties of cementitious composites such as concrete are important indicators of their durability, and are known to be heavily influenced by mechanical loading. In the current work, we use <span class="hlt">meso-scale</span> hygro-mechanical <span class="hlt">modeling</span> with a morphological 3D two phase mortar-aggregate <span class="hlt">model</span>, in conjunction with experimentally obtained properties, to investigate the coupling between mechanical loading and damage and the permeability of the composite. The increase in permeability of a cylindrical test specimen at 28% aggregate fraction during a uniaxial displacement-controlled compression test at 85% of the peak load was measured using a gas permeameter. The mortar's mechanical behavior is assumed to follow the well-known compression damaged plasticity (CDP) <span class="hlt">model</span> with isotropic damage, at varying thresholds, and obtained from different envelope curves. The damaged intrinsic permeability of the mortar evolves according to a logarithmic matching law with progressive loading. We fit the matching law parameters to the experimental result for the test specimen by inverse identification using our <span class="hlt">meso-scale</span> <span class="hlt">model</span>. We then subject a series of virtual composite specimens to quasi-static uniaxial compressive loading with varying boundary conditions to obtain the simulated damage and strain evolutions, and use the damage data and the previously identified parameters to determine the evolution of the macroscopic permeability tensor for the specimens, using a network <span class="hlt">model</span>. We conduct a full parameter study by varying aggregate volume fraction, granulometric distribution, loading/boundary conditions and "matching law" parameters, as well as for different strain-damage thresholds and uniaxial loading envelope curves. Based on this study, we propose Avrami equation-based upper and lower bounds for the evolution of the damaged permeability of the composite.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2004JApMe..43..420F','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2004JApMe..43..420F"><span id="translatedtitle">An Evaluation of <span class="hlt">Mesoscale</span> <span class="hlt">Model</span> Predictions of Down-Valley and Canyon Flows and Their Consequences Using Doppler Lidar Measurements during VTMX 2000.</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Fast, Jerome D.; Darby, Lisa S.</p> <p>2004-04-01</p> <p>A <span class="hlt">mesoscale</span> <span class="hlt">model</span>, a Lagrangian particle dispersion <span class="hlt">model</span>, and extensive Doppler lidar wind measurements during the Vertical Transport and Mixing (VTMX) 2000 field campaign were used to examine converging flows over the Salt Lake valley in Utah and their effect on vertical mixing at night and during the morning transition period. The simulated wind components were transformed into radial velocities to make a direct comparison with about 1.3 million Doppler lidar data points and to evaluate critically the spatial variations in the simulated wind fields aloft. The <span class="hlt">mesoscale</span> <span class="hlt">model</span> captured reasonably well the general features of the observed circulations, including the daytime up-valley flow; the nighttime slope, canyon, and down-valley flows; and the convergence of the flows over the valley. When there were errors in the simulated wind fields, they were usually associated with the timing, structure, or strength of specific flows. The simulated flow reversal during the evening transition period produced ascending motions over much of the valley atmosphere in the absence of significant ambient winds. Valley-mean vertical velocities became nearly zero as down-valley flow developed, but vertical velocities between 5 and 15 cm s-1 occurred where downslope, canyon, and down-valley flows converged, and vertical velocities greater than 50 cm s-1 were produced by hydraulic jumps. A fraction of tracer released at the surface was transported up to the height of the surrounding mountains; however, higher concentrations were produced aloft for evenings characterized by well-developed drainage circulations. Simulations with and without vertical motions in the particle <span class="hlt">model</span> produced large differences in the tracer concentrations at specific locations and times, but the amount of tracer moving out of the valley atmosphere differed by only 5% or less. Despite the stability, turbulence produced by vertical wind shears mixed particles several hundred meters above the surface stable</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/27607648','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/27607648"><span id="translatedtitle">Estimating the surface layer refractive index structure constant over snow and sea ice using Monin-Obukhov similarity theory with a <span class="hlt">mesoscale</span> atmospheric <span class="hlt">model</span>.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Qing, Chun; Wu, Xiaoqing; Huang, Honghua; Tian, Qiguo; Zhu, Wenyue; Rao, Ruizhong; Li, Xuebin</p> <p>2016-09-01</p> <p>Since systematic direct measurements of refractive index structure constant ( Cn2) for many climates and seasons are not available, an indirect approach is developed in which Cn2 is estimated from the <span class="hlt">mesoscale</span> atmospheric <span class="hlt">model</span> outputs. In previous work, we have presented an approach that a state-of-the-art <span class="hlt">mesoscale</span> atmospheric <span class="hlt">model</span> called Weather Research and Forecasting (WRF) <span class="hlt">model</span> coupled with Monin-Obukhov Similarity (MOS) theory which can be used to estimate surface layer Cn2 over the ocean. Here this paper is focused on surface layer Cn2 over snow and sea ice, which is the extending of estimating surface layer Cn2 utilizing WRF <span class="hlt">model</span> for ground-based optical application requirements. This powerful approach is validated against the corresponding 9-day Cn2 data from a field campaign of the 30th Chinese National Antarctic Research Expedition (CHINARE). We employ several statistical operators to assess how this approach performs. Besides, we present an independent analysis of this approach performance using the contingency tables. Such a method permits us to provide supplementary key information with respect to statistical operators. These methods make our analysis more robust and permit us to confirm the excellent performances of this approach. The reasonably good agreement in trend and magnitude is found between estimated values and measurements overall, and the estimated Cn2 values are even better than the ones obtained by this approach over the ocean surface layer. The encouraging performance of this approach has a concrete practical implementation of ground-based optical applications over snow and sea ice.</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://www.ncbi.nlm.nih.gov/pubmed/27607648','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/27607648"><span id="translatedtitle">Estimating the surface layer refractive index structure constant over snow and sea ice using Monin-Obukhov similarity theory with a <span class="hlt">mesoscale</span> atmospheric <span class="hlt">model</span>.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Qing, Chun; Wu, Xiaoqing; Huang, Honghua; Tian, Qiguo; Zhu, Wenyue; Rao, Ruizhong; Li, Xuebin</p> <p>2016-09-01</p> <p>Since systematic direct measurements of refractive index structure constant ( Cn2) for many climates and seasons are not available, an indirect approach is developed in which Cn2 is estimated from the <span class="hlt">mesoscale</span> atmospheric <span class="hlt">model</span> outputs. In previous work, we have presented an approach that a state-of-the-art <span class="hlt">mesoscale</span> atmospheric <span class="hlt">model</span> called Weather Research and Forecasting (WRF) <span class="hlt">model</span> coupled with Monin-Obukhov Similarity (MOS) theory which can be used to estimate surface layer Cn2 over the ocean. Here this paper is focused on surface layer Cn2 over snow and sea ice, which is the extending of estimating surface layer Cn2 utilizing WRF <span class="hlt">model</span> for ground-based optical application requirements. This powerful approach is validated against the corresponding 9-day Cn2 data from a field campaign of the 30th Chinese National Antarctic Research Expedition (CHINARE). We employ several statistical operators to assess how this approach performs. Besides, we present an independent analysis of this approach performance using the contingency tables. Such a method permits us to provide supplementary key information with respect to statistical operators. These methods make our analysis more robust and permit us to confirm the excellent performances of this approach. The reasonably good agreement in trend and magnitude is found between estimated values and measurements overall, and the estimated Cn2 values are even better than the ones obtained by this approach over the ocean surface layer. The encouraging performance of this approach has a concrete practical implementation of ground-based optical applications over snow and sea ice. PMID:27607648</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/19073474','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/19073474"><span id="translatedtitle">Independence and interdependence in collective decision making: an agent-based <span class="hlt">model</span> of <span class="hlt">nest</span>-site choice by honeybee swarms.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>List, Christian; Elsholtz, Christian; Seeley, Thomas D</p> <p>2009-03-27</p> <p>Condorcet's jury theorem shows that when the members of a group have noisy but independent information about what is best for the group as a whole, majority decisions tend to outperform dictatorial ones. When voting is supplemented by communication, however, the resulting interdependencies between decision makers can strengthen or undermine this effect: they can facilitate information pooling, but also amplify errors. We consider an intriguing non-human case of independent information pooling combined with communication: the case of <span class="hlt">nest</span>-site choice by honeybee (Apis mellifera) swarms. It is empirically well documented that when there are different <span class="hlt">nest</span> sites that vary in quality, the bees usually choose the best one. We develop a new agent-based <span class="hlt">model</span> of the bees' decision process and show that its remarkable reliability stems from a particular interplay of independence and interdependence between the bees.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2010ems..confE.760B','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2010ems..confE.760B"><span id="translatedtitle">Atmospheric Boundary Layer wind profile at a flat coastal site - wind speed lidar measurements and <span class="hlt">mesoscale</span> <span class="hlt">modeling</span> results during a summer period</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Batchvarova, E.; Gryning, S.-E.; Hahmann, A.; Peña, A.; Mikkelsen, T.</p> <p>2010-09-01</p> <p>The wind profile above the surface layer up to 1 kilometer is presently a challenge for wind energy assessment studies and air pollution applications, as instruments for high resolution (in time and space) measurements were rarely available until recently and <span class="hlt">mesoscale</span> meteorological <span class="hlt">models</span> have difficulties to predict it, due to complex phenomena taking place in nature and not accounted for in the ABL parameterizations currently used. Worldwide an effort is going on to emphasize the important role of boundary layer research in various direct applications (as wind energy and air pollution) and in weather forecast <span class="hlt">models</span>. Contributing to this effort are the Danish Research Agency Strategic Research Council (Sagsnr. 2104-08-0025) "Tall wind project" and the EU FP7-People-IEF VSABLA (PIEF-GA-2009-237471). The data analyzed here are presenting a summer period of wind lidar (WSL70) measurements at a site at the West coast of Jutland, Denmark, situated approximately 2 km inland. Therefore over water conditions are defining the structure of the boundary layer at westerly winds, while the land surface is felt only within the internal boundary layer estimated in previous studies as about 80 - 100 m deep at the site. Patterns of the wind field and wind profiles over the North Sea up to 1 km height are studied based on observations and <span class="hlt">mesoscale</span> <span class="hlt">modelling</span> results. Simultaneously, the height of the atmospheric boundary layer is estimated from aerosol lidars backscatter analysis and thus providing a rich data set for testing and development of new parametrizations for the wind profile within the entire atmospheric boundary layer over different surfaces.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/servlets/purl/1104951','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/servlets/purl/1104951"><span id="translatedtitle">Use of ARM observations and numerical <span class="hlt">models</span> to determine radiative and latent heating profiles of <span class="hlt">mesoscale</span> convective systems for general circulation <span class="hlt">models</span></span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Robert A. Houze, Jr.</p> <p>2013-11-13</p> <p>We examined cloud radar data in monsoon climates, using cloud radars at Darwin in the Australian monsoon, on a ship in the Bay of Bengal in the South Asian monsoon, and at Niamey in the West African monsoon. We followed on with a more in-depth study of the continental MCSs over West Africa. We investigated whether the West African anvil clouds connected with squall line MCSs passing over the Niamey ARM site could be simulated in a numerical <span class="hlt">model</span> by comparing the observed anvil clouds to anvil structures generated by the Weather Research and Forecasting (WRF) <span class="hlt">mesoscale</span> <span class="hlt">model</span> at high resolution using six different ice-phase microphysical schemes. We carried out further simulations with a cloud-resolving <span class="hlt">model</span> forced by sounding network budgets over the Niamey region and over the northern Australian region. We have devoted some of the effort of this project to examining how well satellite data can determine the global breadth of the anvil cloud measurements obtained at the ARM ground sites. We next considered whether satellite data could be objectively analyzed to so that their large global measurement sets can be systematically related to the ARM measurements. Further differences were detailed between the land and ocean MCS anvil clouds by examining the interior structure of the anvils with the satellite-detected the CloudSat Cloud Profiling Radar (CPR). The satellite survey of anvil clouds in the Indo-Pacific region was continued to determine the role of MCSs in producing the cloud pattern associated with the MJO.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/19830017046','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19830017046"><span id="translatedtitle">Evaluation of the synoptic and <span class="hlt">mesoscale</span> predictive capabilities of a <span class="hlt">mesoscale</span> atmospheric simulation system</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Koch, S. E.; Skillman, W. C.; Kocin, P. J.; Wetzel, P. J.; Brill, K.; Keyser, D. A.; Mccumber, M. C.</p> <p>1983-01-01</p> <p>The overall performance characteristics of a limited area, hydrostatic, fine (52 km) mesh, primitive equation, numerical weather prediction <span class="hlt">model</span> are determined in anticipation of satellite data assimilations with the <span class="hlt">model</span>. The synoptic and <span class="hlt">mesoscale</span> predictive capabilities of version 2.0 of this <span class="hlt">model</span>, the <span class="hlt">Mesoscale</span> Atmospheric Simulation System (MASS 2.0), were evaluated. The two part study is based on a sample of approximately thirty 12h and 24h forecasts of atmospheric flow patterns during spring and early summer. The synoptic scale evaluation results benchmark the performance of MASS 2.0 against that of an operational, synoptic scale weather prediction <span class="hlt">model</span>, the Limited area Fine Mesh (LFM). The large sample allows for the calculation of statistically significant measures of forecast accuracy and the determination of systematic <span class="hlt">model</span> errors. The synoptic scale benchmark is required before unsmoothed <span class="hlt">mesoscale</span> forecast fields can be seriously considered.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/26587252','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/26587252"><span id="translatedtitle">Reduced entomopathogen abundance in Myrmica ant <span class="hlt">nests</span>-testing a possible immunological benefit of myrmecophily using Galleria mellonella as a <span class="hlt">model</span>.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Schär, Sämi; Larsen, Louise L M; Meyling, Nicolai V; Nash, David R</p> <p>2015-10-01</p> <p>Social insects such as ants have evolved collective rather than individual immune defence strategies against diseases and parasites at the level of their societies (colonies), known as social immunity. Ants frequently host other arthropods, so-called myrmecophiles, in their <span class="hlt">nests</span>. Here, we tested the hypothesis that myrmecophily may partly arise from selection for exploiting the ants' social immunity. We used larvae of the wax moth Galleria mellonella as '<span class="hlt">model</span> myrmecophiles' (baits) to test this hypothesis. We found significantly reduced abundance of entomopathogens in ant <span class="hlt">nests</span> compared with the surrounding environment. Specific entomopathogen groups (Isaria fumosorosea and nematodes) were also found to be significantly less abundant inside than outside ant <span class="hlt">nests</span>, whereas one entomopathogen (Beauveria brongniartii) was significantly more abundant inside <span class="hlt">nests</span>. We therefore hypothesize that immunological benefits of entering ant <span class="hlt">nests</span> may provide us a new explanation of why natural selection acts in favour of such a life-history strategy.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/26117128','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/26117128"><span id="translatedtitle"><span class="hlt">Nested</span> arithmetic progressions of oscillatory phases in Olsen's enzyme reaction <span class="hlt">model</span>.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Gallas, Marcia R; Gallas, Jason A C</p> <p>2015-06-01</p> <p>We report some regular organizations of stability phases discovered among self-sustained oscillations of a biochemical oscillator. The signature of such organizations is a <span class="hlt">nested</span> arithmetic progression in the number of spikes of consecutive windows of periodic oscillations. In one of them, there is a main progression of windows whose consecutive number of spikes differs by one unit. Such windows are separated by a secondary progression of smaller windows whose number of spikes differs by two units. Another more complex progression involves a fan-like <span class="hlt">nested</span> alternation of stability phases whose number of spikes seems to grow indefinitely and to accumulate methodically in cycles. Arithmetic progressions exist abundantly in several control parameter planes and can be observed by tuning just one among several possible rate constants governing the enzyme reaction.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/20020061380','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20020061380"><span id="translatedtitle"><span class="hlt">Mesoscale</span> Convective Systems During SCSMEX: Simulations with 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, J.; Shie, C. -L.; Lau, W. K. -M.; Kakar, R.; Starr, David O' C. (Technical Monitor)</p> <p>2002-01-01</p> <p>The South China Sea Monsoon Experiment (SCSMEX) was conducted in May-June 1998. One of its major objectives is to better understand the key physical processes for the onset and evolution of the summer monsoon over Southeast Asia and southern China (Lau et al. 2000). Multiple observation platforms (e.g., soundings, Doppler radar, ships, wind seafarers, radiometers, etc.) during SCSMEX provided a first attempt at investigating the detailed characteristics of convection and circulation changes, associated with monsoons over the South China Sea region. SCSMEX also provided precipitation derived from atmospheric budgets (Johnson and Ciesielski 2002) and comparison to those obtained from the Tropical Rainfall Measuring Mission (TRMM). In this paper, a regional climate <span class="hlt">model</span> and a cloud-resolving <span class="hlt">model</span> are used to perform multi-day integrations to understand the precipitation processes associated with the summer monsoon over Southeast Asia and southern China. The regional climate <span class="hlt">model</span> is used to understand the soil - precipitation interaction and feedback associated with a flood event that occurred in and around China's Atlantic River during SCSMEX. Sensitivity tests on various land surface <span class="hlt">models</span>, cumulus parameterization schemes (CASE), sea surface temperature (SST) variations and midlatitude influences are also performed to understand the processes associated with the onset of the monsoon over the S. China Sea during SCSMEX. Cloud-resolving <span class="hlt">models</span> (CRMs) use more sophisticated and physically realistic parameterizations of cloud microphysical processes with very fine spatial and temporal resolution. One of the major characteristics of CRMs is an explicit interaction between clouds, radiation and the land/ocean surface. It is for this reason that GEWEX (Global Energy and Water Cycle Experiment) has formed the GCSS (GEWEX Cloud System Study) expressly for the purpose of improving the representation of the moist processes in large-scale <span class="hlt">models</span> using CRMs. The Goddard</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://ntrs.nasa.gov/search.jsp?R=20020081020&hterms=soil+after+flooding&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D80%26Ntt%3Dsoil%2Bafter%2Bflooding','NASA-TRS'); return false;" href="http://ntrs.nasa.gov/search.jsp?R=20020081020&hterms=soil+after+flooding&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D80%26Ntt%3Dsoil%2Bafter%2Bflooding"><span id="translatedtitle"><span class="hlt">Mesoscale</span> Convective Systems During SCSMEX: Simulations with 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, J.-H.; Shie, C.-L.; Lau, W. K.-M.; Kakar, R.; Starr, David (Technical Monitor)</p> <p>2002-01-01</p> <p>The South China Sea Monsoon Experiment (SCSMEX) was conducted in May-June 1998. One of its major objectives is to better understand the key physical processes for the onset and evolution of the summer monsoon over Southeast Asia and southern China. Multiple observation platforms (e.g., upper-air soundings, Doppler radar, ships, wind profilers, radiometers, etc.) during SCSMEX provided a first attempt at investigating the detailed characteristics of convection and circulation changes associated with monsoons over the South China Sea region. SCSMEX also provided precipitation derived from atmospheric budgets and comparison to those obtained from the Tropical Rainfall Measuring Mission (TRMM). In this paper, a regional scale <span class="hlt">model</span> (with grid size of 20 km) and Goddard Cumulus Ensemble (GCE) <span class="hlt">model</span> (with 1 km grid size) are used to perform multi-day integration to understand the precipitation processes associated with the summer monsoon over Southeast Asia and southern China. The regional climate <span class="hlt">model</span> is used to understand the soil-precipitation interaction and feedback associated with a flood event that occurred in and around China's Yantz River during SCSMEX Sensitivity tests on various land surface <span class="hlt">models</span>, sea surface temperature (SST) variations, and cloud processes are performed to understand the precipitation processes associated with the onset of the monsoon over the S. China Sea during SCSMEX. 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. Cloud processes can effect the precipitation pattern while SST variation can effect the precipitation amounts over both land and ocean. The exact location (region) of the flooding can be effected by the soil-rainfall feedback. The GCE-<span class="hlt">model</span> results captured many observed precipitation characteristics because it used a fine grid size. For example, the <span class="hlt">model</span> simulated rainfall temporal variation compared quite well to the sounding-estimated rainfall. The</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014AGUFMGC33E0568F','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014AGUFMGC33E0568F"><span id="translatedtitle">Application of a <span class="hlt">Mesoscale</span> Atmospheric Coupled Fire <span class="hlt">Model</span> BRAMS-FIRE to Alentejo Woodland Fire and Comparison of Performance with the Fire <span class="hlt">Model</span> WRF-Sfire.</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Freitas, S. R.; Menezes, I. C.; Stockler, R.; Mello, R.; Ribeiro, N. A.; Corte-Real, J. A. M.; Surový, P.</p> <p>2014-12-01</p> <p><span class="hlt">Models</span> of fuel with the identification of vegetation patterns of Montado ecosystem in Portugal was incorporated in the <span class="hlt">mesoscale</span> Brazilian Atmospheric <span class="hlt">Modeling</span> System (BRAMS) and coupled with a spread woodland fire <span class="hlt">model</span>. The BRAMS-FIRE is a new system developed by the "Centro de Previsão de Tempo e Estudos Climáticos" (CPTEC/INPE, Brazil) and the "Instituto de Ciências Agrárias e Ambientais Mediterrâneas" (ICAAM, Portugal). The fire <span class="hlt">model</span> used in this effort was originally, developed by Mandel et al. (2013) and further incorporated in the Weather Research and Forecast <span class="hlt">model</span> (WRF). Two grids of high spatial resolution were configured with surface input data and fuel <span class="hlt">models</span> integrated for simulations using both <span class="hlt">models</span> BRAMS-FIRE and WRF-SFIRE. One grid was placed in the plain land near Beja and the other one in the hills of Ossa to evaluate different types of fire propagation and calibrate BRAMS-FIRE. The objective is simulating the effects of atmospheric circulation in local scale, namely the movements of the heat front and energy release associated to it, obtained by this two <span class="hlt">models</span> in an episode of woodland fire which took place in Alentejo area in the last decade, for application to planning and evaluations of agro woodland fire risks. We aim to <span class="hlt">model</span> the behavior of forest fires through a set of equations whose solutions provide quantitative values of one or more variables related to the propagation of fire, described by semi-empirical expressions that are complemented by experimental data allow to obtain the main variables related advancing the perimeter of the fire, as the propagation speed, the intensity of the fire front and fuel consumption and its interaction with atmospheric dynamic system. References Mandel, J., J. D. Beezley, G. Kelman, A. K. Kochanski, V. Y. Kondratenko, B. H. Lynn, and M. Vejmelka, 2013. New features in WRF-SFIRE and the wildfire forecasting and danger system in Israel. Natural Hazards and Earth System Sciences, submitted</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015EGUGA..17.7861M','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015EGUGA..17.7861M"><span id="translatedtitle">Application of a <span class="hlt">mesoscale</span> atmospheric coupled fire <span class="hlt">model</span> BRAMS-SFIRE to Alentejo wildland fire and comparison of performance with the fire <span class="hlt">model</span> WRF-SFIRE</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Menezes, Isilda; Freitas, Saulo; Stockler, Rafael; Mello, Rafael; Ribeiro, Nuno; Corte-Real, João; Surový, Peter</p> <p>2015-04-01</p> <p><span class="hlt">Models</span> of fuel with the identification of vegetation patterns of Montado ecosystem in Portugal was incorporated in the <span class="hlt">mesoscale</span> Brazilian Atmospheric <span class="hlt">Modeling</span> System (BRAMS) and coupled with a spread wildland fire <span class="hlt">model</span>. The BRAMS-FIRE is a new system developed by the Centro de Previsão de Tempo e Estudos Climáticos (CPTEC/INPE, Brazil) and the Instituto de Ciências Agrárias e Ambientais Mediterrâneas (ICAAM, Portugal). The fire <span class="hlt">model</span> used in this effort was originally, developed by Mandel et al. (2013) and further incorporated in the Weather Research and Forecast <span class="hlt">model</span> (WRF). Two grids of high spatial resolution were configured with surface input data and fuel <span class="hlt">models</span> integrated for simulations using both <span class="hlt">models</span> BRAMS-SFIRE and WRF-SFIRE. One grid was placed in the plain land and the other one in the hills to evaluate different types of fire propagation and calibrate BRAMS-SFIRE. The objective is simulating the effects of atmospheric circulation in local scale, namely the movements of the heat front and energy release associated to it, obtained by this two <span class="hlt">models</span> in an episode of wildland fire which took place in Alentejo area in the last decade, for application to planning and evaluations of agro wildland fire risks. We aim to <span class="hlt">model</span> the behavior of forest fires through a set of equations whose solutions provide quantitative values of one or more variables related to the propagation of fire, described by semi-empirical expressions that are complemented by experimental data allow to obtain the main variables related advancing the perimeter of the fire, as the propagation speed, the intensity of the fire front and fuel consumption and its interaction with atmospheric dynamic system References Mandel, J., J. D. Beezley, G. Kelman, A. K. Kochanski, V. Y. Kondratenko, B. H. Lynn, and M. Vejmelka, 2013. New features in WRF-SFIRE and the wildfire forecasting and danger system in Israel. Natural Hazards and Earth System Sciences, submitted, Numerical Wildfires, Carg</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/26097744','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/26097744"><span id="translatedtitle">A daily global <span class="hlt">mesoscale</span> ocean eddy dataset from satellite altimetry.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Faghmous, James H; Frenger, Ivy; Yao, Yuanshun; Warmka, Robert; Lindell, Aron; Kumar, Vipin</p> <p>2015-01-01</p> <p><span class="hlt">Mesoscale</span> ocean eddies are ubiquitous coherent rotating structures of water with radial scales on the order of 100 kilometers. Eddies play a key role in the transport and mixing of momentum and tracers across the World Ocean. We present a global daily <span class="hlt">mesoscale</span> ocean eddy dataset that contains ~45 million <span class="hlt">mesoscale</span> features and 3.3 million eddy trajectories that persist at least two days as identified in the AVISO dataset over a period of 1993-2014. This dataset, along with the open-source eddy identification software, extract eddies with any parameters (minimum size, lifetime, etc.), to study global eddy properties and dynamics, and to empirically estimate the impact eddies have on mass or heat transport. Furthermore, our open-source software may be used to identify <span class="hlt">mesoscale</span> features in <span class="hlt">model</span> simulations and compare them to observed features. Finally, this dataset can be used to study the interaction between <span class="hlt">mesoscale</span> ocean eddies and other components of the Earth System.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://ntrs.nasa.gov/search.jsp?R=20000111068&hterms=soil+after+flooding&qs=N%3D0%26Ntk%3DAll%26Ntx%3Dmode%2Bmatchall%26Ntt%3Dsoil%2Bafter%2Bflooding','NASA-TRS'); return false;" href="http://ntrs.nasa.gov/search.jsp?R=20000111068&hterms=soil+after+flooding&qs=N%3D0%26Ntk%3DAll%26Ntx%3Dmode%2Bmatchall%26Ntt%3Dsoil%2Bafter%2Bflooding"><span id="translatedtitle">Soil Moisture and <span class="hlt">Mesoscale</span> Convective Complex Development During the 1993 US Midwest Flood: Results from the MM5-PLACE Atm