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Sample records for nested mesoscale model

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

    NASA Technical Reports Server (NTRS)

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

    1983-01-01

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

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

    NASA Technical Reports Server (NTRS)

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

    1983-01-01

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

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

    NASA Astrophysics Data System (ADS)

    Chow, Fotini; Marjanovic, Nikola; Mirocha, Jeffrey

    2014-11-01

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

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

    NASA Astrophysics Data System (ADS)

    Bongartz, K.

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

  5. Nested mesoscale-to-LES modeling of the atmospheric boundary layer in the presence of under-resolved convective structures

    DOE PAGES

    Mazzaro, Laura J.; Munoz-Esparza, Domingo; Lundquist, Julie K.; ...

    2017-07-06

    Multiscale atmospheric simulations can be computationally prohibitive, as they require large domains and fine spatiotemporal resolutions. Grid-nesting can alleviate this by bridging mesoscales and microscales, but one turbulence scheme must run at resolutions within a range of scales known as the terra incognita (TI). TI grid-cell sizes can violate both mesoscale and microscale subgrid-scale parametrization assumptions, resulting in unrealistic flow structures. Herein we assess the impact of unrealistic lateral boundary conditions from parent mesoscale simulations at TI resolutions on nested large eddy simulations (LES), to determine whether parent domains bias the nested LES. We present a series of idealized nestedmore » mesoscale-to-LES runs of a dry convective boundary layer (CBL) with different parent resolutions in the TI. We compare the nested LES with a stand-alone LES with periodic boundary conditions. The nested LES domains develop ~20% smaller convective structures, while potential temperature profiles are nearly identical for both the mesoscales and LES simulations. The horizontal wind speed and surface wind shear in the nested simulations closely resemble the reference LES. Heat fluxes are overestimated by up to ~0.01 K m s–1 in the top half of the PBL for all nested simulations. Overestimates of turbulent kinetic energy (TKE) and Reynolds stress in the nested domains are proportional to the parent domain's grid-cell size, and are almost eliminated for the simulation with the finest parent grid-cell size. Furthermore, based on these results, we recommend that LES of the CBL be forced by mesoscale simulations with the finest practical resolution.« less

  6. 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.

  7. Validation of mesoscale models

    NASA Technical Reports Server (NTRS)

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

    1993-01-01

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

  8. Modeling mesoscale eddies

    NASA Astrophysics Data System (ADS)

    Canuto, V. M.; Dubovikov, M. S.

    Mesoscale eddies are not resolved in coarse resolution ocean models and must be modeled. They affect both mean momentum and scalars. At present, no generally accepted model exists for the former; in the latter case, mesoscales are modeled with a bolus velocity u∗ to represent a sink of mean potential energy. However, comparison of u∗(model) vs. u∗ (eddy resolving code, [J. Phys. Ocean. 29 (1999) 2442]) has shown that u∗(model) is incomplete and that additional terms, "unrelated to thickness source or sinks", are required. Thus far, no form of the additional terms has been suggested. To describe mesoscale eddies, we employ the Navier-Stokes and scalar equations and a turbulence model to treat the non-linear interactions. We then show that the problem reduces to an eigenvalue problem for the mesoscale Bernoulli potential. The solution, which we derive in analytic form, is used to construct the momentum and thickness fluxes. In the latter case, the bolus velocity u∗ is found to contain two types of terms: the first type entails the gradient of the mean potential vorticity and represents a positive contribution to the production of mesoscale potential energy; the second type of terms, which is new, entails the velocity of the mean flow and represents a negative contribution to the production of mesoscale potential energy, or equivalently, a backscatter process whereby a fraction of the mesoscale potential energy is returned to the original reservoir of mean potential energy. This type of terms satisfies the physical description of the additional terms given by [J. Phys. Ocean. 29 (1999) 2442]. The mesoscale flux that enters the momentum equations is also contributed by two types of terms of the same physical nature as those entering the thickness flux. The potential vorticity flux is also shown to contain two types of terms: the first is of the gradient-type while the other terms entail the velocity of the mean flow. An expression is derived for the mesoscale

  9. 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.

  10. 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.

  11. The multiple nesting of mesoscale, submesoscale, and nonhydrostatic microscale numerical models for a case of mesocyclogenesis and severe storm development

    NASA Technical Reports Server (NTRS)

    Kaplan, M. L.; Gooden, A. L.

    1977-01-01

    A fundamental approach involving the integration of two different numerical models over several different spatial mesh lengths is considered. Model I is a hydrostatic, incompressible, and adiabatic primitive (Newtonian) equation set with no boundary layer forcing, i.e., surface heat or moisture flux or external frictional stresses. Typically this model is initialized from conventional radiosonde data and run for a 12-15 hour forecast period over a 40 km horizontal mesh. If phase I of the tornado developmental processes develops, the data is 'frozen' in space and time, interpolated to a 20 km mesh, and integrated for a shorter time period (3 hours) with a shorter time step. Model II is a nonhydrostatic compressible 18-level complement of model I. If model II indicates the development of the intensification of phase V dynamical processes, the data is frozen and interpolated to finer mesh lengths until the tornadic circulation system is approximated

  12. The multiple nesting of mesoscale, submesoscale, and nonhydrostatic microscale numerical models for a case of mesocyclogenesis and severe storm development

    NASA Technical Reports Server (NTRS)

    Kaplan, M. L.; Gooden, A. L.

    1977-01-01

    A fundamental approach involving the integration of two different numerical models over several different spatial mesh lengths is considered. Model I is a hydrostatic, incompressible, and adiabatic primitive (Newtonian) equation set with no boundary layer forcing, i.e., surface heat or moisture flux or external frictional stresses. Typically this model is initialized from conventional radiosonde data and run for a 12-15 hour forecast period over a 40 km horizontal mesh. If phase I of the tornado developmental processes develops, the data is 'frozen' in space and time, interpolated to a 20 km mesh, and integrated for a shorter time period (3 hours) with a shorter time step. Model II is a nonhydrostatic compressible 18-level complement of model I. If model II indicates the development of the intensification of phase V dynamical processes, the data is frozen and interpolated to finer mesh lengths until the tornadic circulation system is approximated

  13. 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.

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

    NASA Astrophysics Data System (ADS)

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

    2008-12-01

    With increasing demand for more accurate atmospheric simulations for wind turbine micrositing, for operational wind power forecasting, and for more reliable turbine design, simulations of atmospheric flow with resolution of tens of meters or higher are required. These time-dependent large-eddy simulations (LES) account for complex terrain and resolve individual atmospheric eddies on length scales smaller than turbine blades. These small-domain high-resolution simulations are possible with a range of commercial and open- source software, including the Weather Research and Forecasting (WRF) model. In addition to "local" sources of turbulence within an LES domain, changing weather conditions outside the domain can also affect flow, suggesting that a mesoscale model provide boundary conditions to the large-eddy simulations. Nesting a large-eddy simulation within a mesoscale model requires nuanced representations of turbulence. Our group has improved the Weather and Research Forecating model's (WRF) LES capability by implementing the Nonlinear Backscatter and Anisotropy (NBA) subfilter stress model following Kosoviæ (1997) and an explicit filtering and reconstruction technique to compute the Resolvable Subfilter-Scale (RSFS) stresses (following Chow et al, 2005). We have also implemented an immersed boundary method (IBM) in WRF to accommodate complex terrain. These new models improve WRF's LES capabilities over complex terrain and in stable atmospheric conditions. We demonstrate approaches to nesting LES within a mesoscale simulation for farms of wind turbines in hilly regions. Results are sensitive to the nesting method, indicating that care must be taken to provide appropriate boundary conditions, and to allow adequate spin-up of turbulence in the LES domain. This work is performed under the auspices of the U.S. Department of Energy by Lawrence Livermore National Laboratory under Contract DE-AC52-07NA27344.

  15. 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.

  16. Saharan Cyclogenesis As Seen From Mesoscale Modeling

    NASA Astrophysics Data System (ADS)

    Born, K.; Simmer, C.

    In order to study causes of longterm rainfall variability in Northwestafrica in the framework of IMPETUS Westafrica, typical rainfall events--extratropical fronts, oro- graphically triggered thunderstorms, advection of moist tropical air--were examined in detail using the Lokalmodell (LM) of the German Weather Service. One of the most interesting types of rainfall bearing phenomena are Saharan cyclones, which form usu- ally in the lee of the Atlas Mountains. They have been subject to some studies in the past, because they may be connected with severe dust storms and strong rainfall even in the dry season. With their relatively small vertical extent, their short lifetime and - in most cases - their absence of a clearly visible cold front, they seem to be typical mesoscale cyclones. Nevertheless, a closer view shows that these cyclones are con- nected with strong inactive synoptic scale cold fronts. Multiscale interactions, i. e. thunderstorms occurring in the warm sector of Saharan cyclones, rapid movement and synoptic scale forcing makes them to interesting objects for mesoscale modelling. The convection parameterization--which has to be adapted to the mesoscale-- as well as the nesting into initial and boundary data are very important for the development of Saharan cyclones in the model environment.

  17. Mesoscale modeling of the severe thunderstorm environment

    NASA Technical Reports Server (NTRS)

    Koch, Steven E.

    1988-01-01

    The abilities of limited-area mesoscale models to provide accurate predictions of the environment of midlatitude severe thunderstorms and the possible feedback effects of the storms upon their environment are reviewed. Mesoaplha-scale models, mesobeta models, and terrain-induced mesoscale systems are discussed. The importance of the initial state and model numerics and physics is examined. It is found that mesoscale models must be run locally if they are to be used for short-range forecasting.

  18. Relevance of meso-scales a two-way-nesting approach

    NASA Astrophysics Data System (ADS)

    Thürkow, Markus; Kirchner, Ingo; Ulbrich, Uwe; Weiher, Stefan; Will, Andreas

    2014-05-01

    The aim of the MesoTel project presented here is to improve (decadal) forecasts for Europe by focusing on the feedback of the meso-beta-scale and large scales in a specific key region, where synoptic systems, relevant for European weather and climate, develop - Central America - North Atlantic (CANA). Meso-beta-scale atmospheric dynamics affect the development of cyclones and Rossby wave trains, which again affect ocean dynamics. As regional feedbacks are expected to modify the development of the large scales and the conditions for meso-scale processes, a two-way nesting approach is applied. The two-way coupled model system consists of the atmosphere-ocean general circulation model ECHAM6/MPIOM (MPI-ESM) and of the regional climate model COSMO-CLM (CCLM). As MesoTel is part of the MiKlip research initiative, the potential effects on decadal predictions are of particular interest. Ultimately, the influence of the meso-scale processes resolved on the Northern Hemisphere large to planetary scale dynamics and its interannual to decadal predictability shall be investigated. In addition, the concept of coupling using the model components OASIS3-MCT, the MPI-ESM and CCLM is presented. This includes the data exchange, horizontal and vertical interpolation respectively aggregation, as well as the physical coupling strategy which had been elaborated. Using this approach no additional spectral transformations are needed to exchange, nest and correct the prognostic variables. We will present how to fix scalability problems using a sequential coupling and how well the OASIS3-MCT coupler copes with high communication respectively data overflow due to the increasing number of coupling fields using a performance analysis. There will be a section which deals with the horizontal and vertical interpolation as well as aggregation steps to validate the error using different interpolation methods, to analyze the signal to noise ratio out of these transformations. First evaluation

  19. Mesoscale Modeling, Forecasting and Remote Sensing Research.

    DTIC Science & Technology

    remote sensing , cyclonic scale diagnostic studies and mesoscale numerical modeling and forecasting are summarized. Mechanisms involved in the release of potential instability are discussed and simulated quantitatively, giving particular attention to the convective formulation. The basic mesoscale model is documented including the equations, boundary condition, finite differences and initialization through an idealized frontal zone. Results of tests including a three dimensional test with real data, tests of convective/mesoscale interaction and tests with a detailed

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

    NASA Astrophysics Data System (ADS)

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

    2014-12-01

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

  1. 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.

  2. 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

  3. Mesoscale Modeling of Energetic Materials

    DTIC Science & Technology

    2014-10-23

    This briefing represents interim progress towards these goals. 15. SUBJECT TERMS Heterogeneous explosives , Mesoscale dynamics, Level set method...High  Explosives  Research and Development Branch (RWME) – Damage Mechanisms Branch (RWMW) • Goal: Predict survivability of energetic payload of high...the mechanical  behavior of simple  explosive – Pristine – Damaged • Performed simulations on mechanical RVE’s – From XCMT – Idealized • Developed and

  4. 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

  5. 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.

  6. 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.

  7. Mesoscale landscape model of gypsy moth phenology

    Treesearch

    Joseph M. Russo; John G. W. Kelley; Andrew M. Liebhold

    1991-01-01

    A recently-developed high resolution climatological temperature data base was input into a gypsy moth phenology model. The high resolution data were created from a coupling of 30-year averages of station observations and digital elevation data. The resultant maximum and minimum temperatures have about a 1 km resolution which represents meteorologically the mesoscale....

  8. Simulation of the atmospheric thermal circulation of a martian volcano using a mesoscale numerical model.

    PubMed

    Rafkin, Scot C R; Sta Maria, Magdalena R V; Michaels, Timothy I

    2002-10-17

    Mesoscale (<100 km) atmospheric phenomena are ubiquitous on Mars, as revealed by Mars Orbiter Camera images. Numerical models provide an important means of investigating martian atmospheric dynamics, for which data availability is limited. But the resolution of general circulation models, which are traditionally used for such research, is not sufficient to resolve mesoscale phenomena. To provide better understanding of these relatively small-scale phenomena, mesoscale models have recently been introduced. Here we simulate the mesoscale spiral dust cloud observed over the caldera of the volcano Arsia Mons by using the Mars Regional Atmospheric Modelling System. Our simulation uses a hierarchy of nested models with grid sizes ranging from 240 km to 3 km, and reveals that the dust cloud is an indicator of a greater but optically thin thermal circulation that reaches heights of up to 30 km, and transports dust horizontally over thousands of kilometres.

  9. 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.

  10. Mesoscale model forecast verification during monsoon 2008

    NASA Astrophysics Data System (ADS)

    Ashrit, Raghavendra; Mohandas, Saji

    2010-08-01

    There have been very few mesoscale modelling studies of the Indian monsoon, with focus on the verification and intercomparison of the operational real time forecasts. With the exception of Das et al (2008), most of the studies in the literature are either the case studies of tropical cyclones and thunderstorms or the sensitivity studies involving physical parameterization or climate simulation studies. Almost all the studies are based on either National Center for Environmental Prediction (NCEP), USA, final analysis fields (NCEP FNL) or the reanalysis data used as initial and lateral boundary conditions for driving the mesoscale model. Here we present a mesoscale model forecast verification and intercomparison study over India involving three mesoscale models: (i) the Weather Research and Forecast (WRF) model developed at the National Center for Atmospheric Research (NCAR), USA, (ii) the MM5 model developed by NCAR, and (iii) the Eta model of the NCEP, USA. The analysis is carried out for the monsoon season, June to September 2008. This study is unique since it is based entirely on the real time global model forecasts of the National Centre for Medium Range Weather Forecasting (NCMRWF) T254 global analysis and forecast system. Based on the evaluation and intercomparison of the mesoscale model forecasts, we recommend the best model for operational real-time forecasts over the Indian region. Although the forecast mean 850 hPa circulation shows realistic monsoon flow and the monsoon trough, the systematic errors over the Arabian Sea indicate an easterly bias to the north (of mean flow) and westerly bias to the south (of mean flow). This suggests that the forecasts feature a southward shift in the monsoon current. The systematic error in the 850 hPa temperature indicates that largely the WRF model forecasts feature warm bias and the MM5 model forecasts feature cold bias. Features common to all the three models include warm bias over northwest India and cold bias over

  11. A history of mesoscale model development

    NASA Astrophysics Data System (ADS)

    Dudhia, Jimy

    2014-01-01

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

  12. Mesoscale Wind Predictions for Wave Model Evaluation

    DTIC Science & Technology

    2016-06-07

    contains the following components for atmospheric analysis and prediction : complex data quality control ; a multivariate optimum interpolation analysis...subject to a penalty for failing to comply with a collection of information if it does not display a currently valid OMB control number. 1. REPORT DATE 30...SEP 1999 2. REPORT TYPE 3. DATES COVERED 00-00-1999 to 00-00-1999 4. TITLE AND SUBTITLE Mesoscale Wind Predictions for Wave Model Evaluation

  13. Mesoscale Modeling of Chromatin Folding

    NASA Astrophysics Data System (ADS)

    Schlick, Tamar

    2009-03-01

    Eukaryotic chromatin is the fundamental protein/nucleic acid unit that stores the genetic material. Understanding how chromatin fibers fold and unfold in physiological conditions is important for interpreting fundamental biological processes like DNA replication and transcription regulation. Using a mesoscopic model of oligonucleosome chains and tailored sampling protocols, we elucidate the energetics of oligonucleosome folding/unfolding and the role of each histone tail, linker histones, and divalent ions in regulating chromatin structure. The resulting compact topologies reconcile features of the zigzag model with straight linker DNAs with the solenoid model with bent linker DNAs for optimal fiber organization and reveal dynamic and energetic aspects involved.

  14. A new vertical grid nesting capability in the Weather Research and Forecasting (WRF) Model

    DOE PAGES

    Daniels, Megan H.; Lundquist, Katherine A.; Mirocha, Jeffrey D.; ...

    2016-09-16

    Mesoscale atmospheric models are increasingly used for high-resolution (<3 km) simulations to better resolve smaller-scale flow details. Increased resolution is achieved using mesh refinement via grid nesting, a procedure where multiple computational domains are integrated either concurrently or in series. A constraint in the concurrent nesting framework offered by the Weather Research and Forecasting (WRF) Model is that mesh refinement is restricted to the horizontal dimensions. This limitation prevents control of the grid aspect ratio, leading to numerical errors due to poor grid quality and preventing grid optimization. Here, a procedure permitting vertical nesting for one-way concurrent simulation is developedmore » and validated through idealized cases. The benefits of vertical nesting are demonstrated using both mesoscale and large-eddy simulations (LES). Mesoscale simulations of the Terrain-Induced Rotor Experiment (T-REX) show that vertical grid nesting can alleviate numerical errors due to large aspect ratios on coarse grids, while allowing for higher vertical resolution on fine grids. Furthermore, the coarsening of the parent domain does not result in a significant loss of accuracy on the nested domain. LES of neutral boundary layer flow shows that, by permitting optimal grid aspect ratios on both parent and nested domains, use of vertical nesting yields improved agreement with the theoretical logarithmic velocity profile on both domains. Lastly, vertical grid nesting in WRF opens the path forward for multiscale simulations, allowing more accurate simulations spanning a wider range of scales than previously possible.« less

  15. A new vertical grid nesting capability in the Weather Research and Forecasting (WRF) Model

    SciTech Connect

    Daniels, Megan H.; Lundquist, Katherine A.; Mirocha, Jeffrey D.; Wiersema, David J.; Chow, Fotini K.

    2016-09-16

    Mesoscale atmospheric models are increasingly used for high-resolution (<3 km) simulations to better resolve smaller-scale flow details. Increased resolution is achieved using mesh refinement via grid nesting, a procedure where multiple computational domains are integrated either concurrently or in series. A constraint in the concurrent nesting framework offered by the Weather Research and Forecasting (WRF) Model is that mesh refinement is restricted to the horizontal dimensions. This limitation prevents control of the grid aspect ratio, leading to numerical errors due to poor grid quality and preventing grid optimization. Here, a procedure permitting vertical nesting for one-way concurrent simulation is developed and validated through idealized cases. The benefits of vertical nesting are demonstrated using both mesoscale and large-eddy simulations (LES). Mesoscale simulations of the Terrain-Induced Rotor Experiment (T-REX) show that vertical grid nesting can alleviate numerical errors due to large aspect ratios on coarse grids, while allowing for higher vertical resolution on fine grids. Furthermore, the coarsening of the parent domain does not result in a significant loss of accuracy on the nested domain. LES of neutral boundary layer flow shows that, by permitting optimal grid aspect ratios on both parent and nested domains, use of vertical nesting yields improved agreement with the theoretical logarithmic velocity profile on both domains. Lastly, vertical grid nesting in WRF opens the path forward for multiscale simulations, allowing more accurate simulations spanning a wider range of scales than previously possible.

  16. 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.

  17. Mesoscale Modelling of the Response of Aluminas

    SciTech Connect

    Bourne, N. K.

    2006-07-28

    The response of polycrystalline alumina to shock is not well addressed. There are several operating mechanisms that only hypothesized which results in models which are empirical. A similar state of affairs in reactive flow modelling led to the development of mesoscale representations of the flow to illuminate operating mechanisms. In this spirit, a similar effort is undergone for a polycrystalline alumina. Simulations are conducted to observe operating mechanisms at the micron scale. A method is then developed to extend the simulations to meet response at the continuum level where measurements are made. The approach is validated by comparison with continuum experiments. The method and results are presented, and some of the operating mechanisms are illuminated by the observed response.

  18. Nested polyhedra model of turbulence.

    PubMed

    Gürcan, Ö D

    2017-06-01

    A discretization of the wave-number space is proposed, using nested polyhedra, in the form of alternating dodecahedra and icosahedra that are self-similarly scaled. This particular choice allows the possibility of forming triangles using only discretized wave vectors when the scaling between two consecutive dodecahedra is equal to the golden ratio and the icosahedron between the two dodecahedra is the dual of the inner dodecahedron. Alternatively, the same discretization can be described as a logarithmically spaced (with a scaling equal to the golden ratio), nested dodecahedron-icosahedron compounds. A wave vector which points from the origin to a vertex of such a mesh, can always find two other discretized wave vectors that are also on the vertices of the mesh (which is not true for an arbitrary mesh). Thus, the nested polyhedra grid can be thought of as a reduction (or decimation) of the Fourier space using a particular set of self-similar triads arranged approximately in a spherical form. For each vertex (i.e., discretized wave vector) in this space, there are either 9 or 15 pairs of vertices (i.e., wave vectors) with which the initial vertex can interact to form a triangle. This allows the reduction of the convolution integral in the Navier-Stokes equation to a sum over 9 or 15 interaction pairs, transforming the equation in Fourier space to a network of "interacting" nodes that can be constructed as a numerical model, which evolves each component of the velocity vector on each node of the network. This model gives the usual Kolmogorov spectrum of k^{-5/3}. Since the scaling is logarithmic, and the number of nodes for each scale is constant, a very large inertial range (i.e., a very high Reynolds number) with a much lower number of degrees of freedom can be considered. Incidentally, by assuming isotropy and a certain relation between the phases, the model can be used to systematically derive shell models.

  19. Nested polyhedra model of turbulence

    NASA Astrophysics Data System (ADS)

    Gürcan, Ö. D.

    2017-06-01

    A discretization of the wave-number space is proposed, using nested polyhedra, in the form of alternating dodecahedra and icosahedra that are self-similarly scaled. This particular choice allows the possibility of forming triangles using only discretized wave vectors when the scaling between two consecutive dodecahedra is equal to the golden ratio and the icosahedron between the two dodecahedra is the dual of the inner dodecahedron. Alternatively, the same discretization can be described as a logarithmically spaced (with a scaling equal to the golden ratio), nested dodecahedron-icosahedron compounds. A wave vector which points from the origin to a vertex of such a mesh, can always find two other discretized wave vectors that are also on the vertices of the mesh (which is not true for an arbitrary mesh). Thus, the nested polyhedra grid can be thought of as a reduction (or decimation) of the Fourier space using a particular set of self-similar triads arranged approximately in a spherical form. For each vertex (i.e., discretized wave vector) in this space, there are either 9 or 15 pairs of vertices (i.e., wave vectors) with which the initial vertex can interact to form a triangle. This allows the reduction of the convolution integral in the Navier-Stokes equation to a sum over 9 or 15 interaction pairs, transforming the equation in Fourier space to a network of "interacting" nodes that can be constructed as a numerical model, which evolves each component of the velocity vector on each node of the network. This model gives the usual Kolmogorov spectrum of k-5 /3. Since the scaling is logarithmic, and the number of nodes for each scale is constant, a very large inertial range (i.e., a very high Reynolds number) with a much lower number of degrees of freedom can be considered. Incidentally, by assuming isotropy and a certain relation between the phases, the model can be used to systematically derive shell models.

  20. Nested Gulf of Mexico Modeling with HYCOM

    DTIC Science & Technology

    2004-10-29

    Gulf of Mexico Modeling with HYCOM Patrick J. Hogan1 Alan J. Wallcraft1 Ole Martin Smedstad2 1Naval Research Laboratory Stennis Space Center...2004 4. TITLE AND SUBTITLE Nested Gulf of Mexico Modeling with HYCOM 5a. CONTRACT NUMBER 5b. GRANT NUMBER 5c. PROGRAM ELEMENT NUMBER 6. AUTHOR(S...Running Nested Gulf of Mexico • 1/12° Assimilative Nested Gulf of Mexico 1/25° Free-Running Nested Gulf of Mexico

  1. Real-Time Mesoscale Modeling Over Antarctica: The Antarctic Mesoscale Prediction System*.

    NASA Astrophysics Data System (ADS)

    Powers, Jordan G.; Monaghan, Andrew J.; Cayette, Arthur M.; Bromwich, David H.; Kuo, Ying-Hwa; Manning, Kevin W.

    2003-11-01

    *Byrd Polar Research Center Contribution Number 1276In support of the United States Antarctic Program (USAP), the National Center for Atmospheric Research and the Byrd Polar Research Center of The Ohio State University have created the Antarctic Mesoscale Prediction System (AMPS): an experimental, real-time mesoscale modeling system covering Antarctica. AMPS has been designed to serve flight forecasters at McMurdo Station, to support science and operations around the continent, and to be a vehicle for the development of physical parameterizations suitable for polar regions. Since 2000, AMPS has been producing high-resolution forecasts (grids to 3.3 km) with the “Polar MM5,” a version of the fifth-generation Pennsylvania State University NCAR Mesoscale Model tuned for the polar atmosphere. Beyond its basic mission of serving the USAP flight forecasters at McMurdo, AMPS has assisted both in emergency operations to save lives and in programs to explore the extreme polar environment. The former have included a medical evacuation from the South Pole and a marine rescue from the continental margin. The latter have included scientific field campaigns and the daily activities of international Antarctic forecasters and researchers. The AMPS program has been a success in terms of advancing polar mesoscale NWP, serving critical logistical operations of the USAP, and, most visibly, assisting in emergency rescue missions to save lives. The history and performance of AMPS are described and the successes of this unique real-time mesoscale modeling system in crisis support are detailed.

  2. A mesoscale sixth-order numerical modelling system

    NASA Technical Reports Server (NTRS)

    Kaplan, M. L.; Zack, J. W.; Wong, V. C.; Tuccillo, J. J.

    1981-01-01

    A numerical simulation system is currently under development for NASA which is intended to improve the modeling of subsynoptic and mesoscale adjustments associated with cyclogenesis, severe storm development and atmospheric transport processes. The model utilizes a standard hydrostatic sigma-p coordinate primitive equation set, with x,y-space differencing accurate to eighth order. A three-step dynamic initialization procedure is employed between the analysis of real-time data and grid interpolation. Results of an 18-hour simulation during which synoptic scale cyclogenesis, subsynoptic scale jet streak adjustments, mesoscale convergence zones and tornadic storms were observed have shown the present model to have the potential for simulating the fine-scale structure of features associated with cyclogenesis and intense squall-line development. The mesoscale model was also found to produce less truncation than the NWS LFM model, although a frictionless version of the mesoscale model somewhat overdeepens and overaccelerates features.

  3. HYBRID MESOSCALE MODELING OF DYNAMIC GRAIN FRAGMENTATION

    SciTech Connect

    R. SWIFT; C. HAGELBERG; M. HILTL

    2001-04-01

    Fines created by grain fragmentation from shaped-charge, jet perforation treatment often plug-up pores in the vicinity of the perforation tunnel. We analyze and model grain damage on samples recovered from impact tests of dry and water saturated sandstone at stress levels and duration similar to that of perforation loading. Analyses of Scanning Electron Microscope (SEM) images and laser particle size measurements on portions of the recovered samples characterize grain damage and changes in grain size distribution. Hybrid modeling that combines the Discrete Element Method (DEM) with Smooth Particle Hydrodynamics (SPH), and includes mesoscale representation of grain/pore structure, shows how grain damage evolves for dry and wet conditions. Modeling defines behavior in accord with recovered sample analyses as follows: (1) Increase in grain damage is obtained with an increase in stress level and pulse duration. (2) The grains in dry samples are extremely and irregularly fragmented with extensive reduced porosity. (3) Less grain damage and higher porosity is obtained in saturated samples. The influence of pore fluid mitigates the interaction between grains, thus reducing fragmentation damage. (4) Computed particle size distributions are similar in character to measurements.

  4. Meso-NH: Non-hydrostatic mesoscale atmospheric model

    NASA Astrophysics Data System (ADS)

    Laboratoire d'Aérologie; Centre National de Recherches Météorologiques

    2016-12-01

    Meso-NH is the non-hydrostatic mesoscale atmospheric model of the French research community jointly developed by the Laboratoire d'Aérologie (UMR 5560 UPS/CNRS) and by CNRM (UMR 3589 CNRS/Météo-France). Meso-NH incorporates a non-hydrostatic system of equations for dealing with scales ranging from large (synoptic) to small (large eddy) scales while calculating budgets and has a complete set of physical parameterizations for the representation of clouds and precipitation. It is coupled to the surface model SURFEX for representation of surface atmosphere interactions by considering different surface types (vegetation, city, ocean, lake) and allows a multi-scale approach through a grid-nesting technique. Meso-NH is versatile, vectorized, parallelized, and operates in 1D, 2D or 3D; it is coupled with a chemistry module (including gas-phase, aerosol, and aqua-phase components) and a lightning module, and has observation operators that compare model output directly with satellite observations, radar, lidar and GPS.

  5. Coupled Mesoscale Modeling of the Atmosphere and Ocean

    NASA Astrophysics Data System (ADS)

    Hodur, Richard

    2002-08-01

    The Naval Research Laboratory (NRL) has developed the Coupled Ocean/Atmosphere Mesoscale Prediction System (COAMPS^TM). COAMPS is comprised of separate atmosphere and ocean data assimilation systems. The atmospheric portion of COAMPS has been in operational use at the Fleet Numerical Meteorology and Oceanography Center (FNMOC) since 1998, and it has been found to be useful for the prediction of mesoscale weather events in the coastal zone, and in areas of significant topography. A multivariate optimum interpolation (MVOI) analysis is used to construct analyses of the atmosphere using observations from radiosondes, satellites, ships, buoys, aircraft, etc.. Using these analyses, the COAMPS atmospheric model solves the nonhydrostatic form of the primitive equations using moving, multi-nested grids and sophisticated physical parameterizations for boundary layer, precipitation, and radiation. Although the original design of COAMPS was for shared-memory, vector-processor computers, NRL recently teamed with scientists at the Lawrence Livermore National Laboratory (LLNL) to adapt COAMPS for distributed-memory architecture computers. The new version of the COAMPS atmospheric model now supports distributed memory across nodes using the message-passing-interface (MPI), and shared memory across processors using OpenMP. Any arbitrary horizontal domain decomposition and number of halo points can be used for each nest. Tests have demonstrated that the atmospheric model scales to at least 200 processors. The ocean component of COAMPS uses a 3-dimensional MVOI analysis that can assimilate in-situ and remotely-sensed observations, as well as incorporate subsurface thermohaline structure through the use of the Modular Ocean Data Assimilation System (MODAS) synthetic database. The hydrostatic NRL Coastal Ocean Model (NCOM) is the COAMPS ocean model. NCOM uses a hybrid z/sigma vertical coordinate, and uses a 2-dimensional domain decomposition and MPI for use on distributed memory

  6. User's guide to the Penn State/NCAR Mesoscale Modeling System

    NASA Astrophysics Data System (ADS)

    Gill, David O.

    1992-10-01

    An updated version of the Pennsylvania State University/National Center for Atmospheric Research (PSU/NCAR) Mesoscale Modeling system (the MM4 system) is presented. The standard MM4 modeling package employs a Cressman multi-scan isobaric and surface analysis, with a hydrostatic predictive component using a leap frog integration of the flux form of the primitive equations on sigma coordinates. An experimental version has expanded the data ingest routines to allow hybrid isentropic-isobaric + surface analyses. Experimental versions of the model allow split-explicit time integration, several cumulus parameterizations coupled with an explicit moisture scheme, multiple levels of movable nests, relaxation of the hydrostatic assumptions, additional planetary boundary layer schemes, and microphysical packages. Due to the developmental nature of the modeling system, periodic upgrades in documentation are required to keep the manuals in accord with the programs. The document supersedes Penn State/NCAR Mesoscale Model User's Manual--Ver 8.

  7. 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

  8. Meso-Scale Modeling of Polycrystal Deformation

    NASA Astrophysics Data System (ADS)

    Lim, Hojun

    Computational material modeling of material is essential to accelerate material/process design and reduce costs in wide variety of applications. In particular, multi-scale models are gaining momentum in many fields as computers become faster, and finer structures become accessible experimentally. An effective (i.e. sufficiently accurate and fast to have practical impact) multi-scale model of dislocation-based metal plasticity may have many important applications such as metal forming. A two-scale method to predict quantitatively the Hall-Petch effect, as well as dislocation densities and lattice curvatures throughout a polycrystal, has been developed and implemented. Based on a finite element formulation, the first scale is called a Grain-Scale Simulation (GSS) that is standard except for using novel single-crystal constitutive equations that were proposed and tested as part of this work (and which are informed from the second model scale). The GSS allows the determination of local stresses, strains, and slip magnitudes while enforcing compatibility and equilibrium throughout a polycrystal in a finite element sense. The second scale is called here a Meso-Scale Simulation (MSS) which is novel in concept and application. It redistributes the mobile part of the dislocation density within grains consistent with the plastic strain distribution, and enforces slip transmission criteria at grain boundaries that depend on local grain and boundary properties. Stepwise simulation at the two scales proceeds sequentially in order to predict the spatial distribution of dislocation density and the flow stress for each slip system within each grain, and each simulation point. The MSS was formulated with the minimum number of undermined or arbitrary parameters, three. Two of these are related to the shape of the strain hardening curve and the other represents the initial yield. These parameters do not invoke additional length scales. The new model made possible the following

  9. Multiscale Modeling of Mesoscale and Interfacial Phenomena

    NASA Astrophysics Data System (ADS)

    Petsev, Nikolai Dimitrov

    With rapidly emerging technologies that feature interfaces modified at the nanoscale, traditional macroscopic models are pushed to their limits to explain phenomena where molecular processes can play a key role. Often, such problems appear to defy explanation when treated with coarse-grained continuum models alone, yet remain prohibitively expensive from a molecular simulation perspective. A prominent example is surface nanobubbles: nanoscopic gaseous domains typically found on hydrophobic surfaces that have puzzled researchers for over two decades due to their unusually long lifetimes. We show how an entirely macroscopic, non-equilibrium model explains many of their anomalous properties, including their stability and abnormally small gas-side contact angles. From this purely transport perspective, we investigate how factors such as temperature and saturation affect nanobubbles, providing numerous experimentally testable predictions. However, recent work also emphasizes the relevance of molecular-scale phenomena that cannot be described in terms of bulk phases or pristine interfaces. This is true for nanobubbles as well, whose nanoscale heights may require molecular detail to capture the relevant physics, in particular near the bubble three-phase contact line. Therefore, there is a clear need for general ways to link molecular granularity and behavior with large-scale continuum models in the treatment of many interfacial problems. In light of this, we have developed a general set of simulation strategies that couple mesoscale particle-based continuum models to molecular regions simulated through conventional molecular dynamics (MD). In addition, we derived a transport model for binary mixtures that opens the possibility for a wide range of applications in biological and drug delivery problems, and is readily reconciled with our hybrid MD-continuum techniques. Approaches that couple multiple length scales for fluid mixtures are largely absent in the literature, and

  10. An evaluation of the synoptic- and mesoscale predictability of the Mesoscale Atmospheric Simulation System (MASS 2.0) model

    NASA Technical Reports Server (NTRS)

    Koch, S. E.; Skillman, W. C.; Kocin, P. J.; Wetzel, P. J.; Brill, K. F.

    1983-01-01

    A report is presented regarding the synoptic- and mesoscale predictive capabilities of a regional-scale numerical weather prediction model known as the Mesoscale Atmospheric Simulation System (MASS, Version 2.0). The development of this model has been discussed by Kaplan et al. (1982). An evaluation of the performance of MASS 2.0 is based on the study of a sample of approximately thirty 12 h and 24 h forecasts of atmospheric flow patterns over the U.S. during spring and early summer of 1982. A description of model systems is provided, and synoptic-scale evaluation methods are considered along with aspects of mesoscale evaluation methodology, examples of coherent mesoscale information provided by MASS 2.0, the results of a diagnostic study of mesoscale convective systems (MCS), and the results of a limited real-time forecast experiment.

  11. 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.

  12. Nested Gulf of Mexico Modeling with HYCOM

    DTIC Science & Technology

    2005-12-08

    Nested Gulf of Mexico Modeling with HYCOM Patrick J. Hogan Alan J. Wallcraft Naval Research Laboratory Stennis Space Center, MS HYCOM Meeting...valid OMB control number. 1. REPORT DATE DEC 2005 2. REPORT TYPE 3. DATES COVERED 00-00-2005 to 00-00-2005 4. TITLE AND SUBTITLE Nested Gulf of Mexico Modeling...topography is from NRL-DBDB2 • Integrated over 2000-2001 1/25° (~4 km) non-assimilative Nested Gulf of Mexico Possible cross-shelf transport

  13. 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.

  14. Mesoscale to microscale wind farm flow modeling and evaluation: Mesoscale to Microscale Wind Farm Models

    SciTech Connect

    Sanz Rodrigo, Javier; Chávez Arroyo, Roberto Aurelio; Moriarty, Patrick; Churchfield, Matthew; Kosović, Branko; Réthoré, Pierre-Elouan; Hansen, Kurt Schaldemose; Hahmann, Andrea; Mirocha, Jeffrey D.; Rife, Daran

    2016-08-31

    The increasing size of wind turbines, with rotors already spanning more than 150 m diameter and hub heights above 100 m, requires proper modeling of the atmospheric boundary layer (ABL) from the surface to the free atmosphere. Furthermore, large wind farm arrays create their own boundary layer structure with unique physics. This poses significant challenges to traditional wind engineering models that rely on surface-layer theories and engineering wind farm models to simulate the flow in and around wind farms. However, adopting an ABL approach offers the opportunity to better integrate wind farm design tools and meteorological models. The challenge is how to build the bridge between atmospheric and wind engineering model communities and how to establish a comprehensive evaluation process that identifies relevant physical phenomena for wind energy applications with modeling and experimental requirements. A framework for model verification, validation, and uncertainty quantification is established to guide this process by a systematic evaluation of the modeling system at increasing levels of complexity. In terms of atmospheric physics, 'building the bridge' means developing models for the so-called 'terra incognita,' a term used to designate the turbulent scales that transition from mesoscale to microscale. This range of scales within atmospheric research deals with the transition from parameterized to resolved turbulence and the improvement of surface boundary-layer parameterizations. The coupling of meteorological and wind engineering flow models and the definition of a formal model evaluation methodology, is a strong area of research for the next generation of wind conditions assessment and wind farm and wind turbine design tools. Some fundamental challenges are identified in order to guide future research in this area.

  15. 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.

  16. From neurons to nests: nest-building behaviour as a model in behavioural and comparative neuroscience.

    PubMed

    Hall, Zachary J; Meddle, Simone L; Healy, Susan D

    Despite centuries of observing the nest building of most extant bird species, we know surprisingly little about how birds build nests and, specifically, how the avian brain controls nest building. Here, we argue that nest building in birds may be a useful model behaviour in which to study how the brain controls behaviour. Specifically, we argue that nest building as a behavioural model provides a unique opportunity to study not only the mechanisms through which the brain controls behaviour within individuals of a single species but also how evolution may have shaped the brain to produce interspecific variation in nest-building behaviour. In this review, we outline the questions in both behavioural and comparative neuroscience that nest building could be used to address, summarize recent findings regarding the neurobiology of nest building in lab-reared zebra finches and across species building different nest structures, and suggest some future directions for the neurobiology of nest building.

  17. Mesoscale modeling of molecular machines: cyclic dynamics and hydrodynamical fluctuations.

    PubMed

    Cressman, Andrew; Togashi, Yuichi; Mikhailov, Alexander S; Kapral, Raymond

    2008-05-01

    Proteins acting as molecular machines can undergo cyclic internal conformational motions that are coupled to ligand binding and dissociation events. In contrast to their macroscopic counterparts, nanomachines operate in a highly fluctuating environment, which influences their operation. To bridge the gap between detailed microscopic and simple phenomenological descriptions, a mesoscale approach, which combines an elastic network model of a machine with a particle-based mesoscale description of the solvent, is employed. The time scale of the cyclic hinge motions of the machine prototype is strongly affected by hydrodynamical coupling to the solvent.

  18. Refinement of a mesoscale model for large eddy simulation

    NASA Astrophysics Data System (ADS)

    Gasset, Nicolas

    With the advent of wind energy technology, several methods have become mature and are seen today as standard for predicting and forecasting the wind. However, their results are still site dependent, and the increasing sizes of both modern wind turbines and wind farms tackle limits of existing methods. Some triggered processes extend to the junction between microscales and mesoscales.The main objectives of this thesis are thus to identify, implement and evaluate an approach allowing for microscale and mesoscale ABL flow modelling considering the various challenges of modern wind energy applications. A literature review of ABL flow modelling from microscales to mesoscales first provides an overview of the specificities and abilities of existing methods. The combined mesoscale/large eddy simulation (LES) modelling appears to be the most promising approach, and the Compressible Community Mesoscale Model (MC2) is elected as the basis of the method in which the components required for LES are added and implemented. A detailed description of the mathematical model and the numerical aspects of the various components of the LES-capable MC2 are then presented so that a complete view of the proposed approach along with the specificities of its implementation are provided. This further allows to introduce the enhancements and new components of the method (separation of volumetric and deviatoric Reynolds tensor terms, vertical staggering, subgrid scale models, 3D turbulent diffusion, 3D turbulent kinetic energy equation), as well as the adaptation of its operating mode to allow for LES (initialization, large scale geostrophic forcing, surface and lateral boundaries). Finally, fundamental aspects and new components of the proposed approach are evaluated based on theoretical 1D Ekman boundary layer and 3D unsteady shear and buoyancy driven homogeneous surface full ABL cases. The model behaviour at high resolution as well as the components required for LES in MC2 are all finely

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

    NASA Astrophysics Data System (ADS)

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

    2013-12-01

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

  20. Parameterization of Cumulus Convective Cloud Systems in Mesoscale Forecast Models

    DTIC Science & Technology

    2013-09-30

    1 DISTRIBUTION STATEMENT A. Approved for public release; distribution is unlimited. Parameterization of Cumulus Convective Cloud Systems in...parameterization of cumulus convective clouds in mesoscale numerical weather prediction models OBJECTIVES Conduct detailed studies of cloud ...microphysical processes in order to develop a unified parameterization of boundary layer stratocumulus and trade wind cumulus convective clouds . Develop

  1. Comments on the challenge of using mesoscale data in mesoscale numerical models

    NASA Technical Reports Server (NTRS)

    Uccellini, Louis W.

    1987-01-01

    The dangers of addressing the initialization issues for limited-area mesoscale models by extending the lessons learned during the development of global analysis and prediction systems are discussed. Lack of impact with data inserts at one time suggests that the lateral boundary conditions imposed on the limited-area models might force the model simulation toward a preferred solution, work against the new data being inserted into the model and, therefore, limit the potential impact that this data can have on the model system. The second potential pitfall involves the imposition of balance constraints on the data that are being inserted into the model to compute winds from temperature data and/or temperature from wind data.

  2. Runtime system library for parallel finite difference models with nesting

    SciTech Connect

    Michalakes, J.

    1997-03-01

    RSL is a parallel run-time system library for implementing regular-grid models with nesting on distributed memory parallel computers. RSL provides support for automatically decomposing multiple model domains and for redistributing work between processors at run time for dynamic load balancing. A unique feature of RSL is that processor subdomains need not be rectangular patches; rather, grid points are independently allocated to processors, allowing more precisely balanced allocation of work to processors. Communication mechanisms are tailored to the application: RSL provides an efficient high-level stencil exchange operation for updating subdomain ghost areas and interdomain communication to support two-way interaction between nest levels. RSL also provides run-time support for local iteration over subdomains, global-local index translation, and distributed I/O from ordinary Fortran record-blocked data sets. The interface to RSL supports Fortran77 and Fortran90. RSL has been used to parallelize the NCAR/Penn State Mesoscale Model (MM5).

  3. 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

  4. 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.

  5. 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.

  6. 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.

  7. Modeling the mesoscale variability in the Adriatic Sea

    NASA Astrophysics Data System (ADS)

    Korotenko, K. A.

    2007-06-01

    A new high-resolution (<2 km) version of the DieCAST fourth-accuracy-order model for the ocean circulation is proposed for the study of the general circulation, mesoscale structures, and their variability in the Adriatic Sea. The model uses mean seasonal data on the temperature, salinity, buoyancy fluxes, and wind. The data of the COAMPS system with a 4-km resolution were used for the simulation of the sea response to the effects of various winds: Sirocco, Maestro, and two types of boras. The mean monthly runoffs from 38 rivers and mean daily runoffs from 12 main rivers throughout the year were given in the model. The conditions at the open boundary of the Strait of Otranto were given on the basis of the hierarchy of two coarser models for the Adriatic and Mediterranean seas. Due to the extremely weak dissipation and the high resolution (the mesh size is less than the baroclinic radius of deformation, 5 10 km), the model allows one to trace the development of a baroclinic instability along the Italian coast, to simulate mesoscale structures associated with the instability, and to estimate the scales of the structures. Mesoscale filaments, meanders, mushroom-like currents, fronts, and intrusions known from satellite observations were simulated and explained. The scenario of the anomalous upwelling near the Italian coast observed in the summer of 2003 was also simulated and analyzed.

  8. 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.

  9. Anisotropic Mesoscale Eddy Transport in Ocean General Circulation Models

    NASA Astrophysics Data System (ADS)

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

    2014-12-01

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

  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. 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

  12. 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

  13. Multiscale models for synoptic-mesoscale interactions in the ocean

    NASA Astrophysics Data System (ADS)

    Grooms, Ian; Shafer Smith, K.; Majda, Andrew J.

    2012-11-01

    Multiscale analysis is used to derive two sets of coupled models, each based on the same distinguished limit, to represent the interaction of the midlatitude oceanic synoptic scale-where coherent features such as jets and rings form-and the mesoscale, defined by the internal deformation scale. The synoptic scale and mesoscale overlap at low and mid latitudes, and are hence synonymous in much of the oceanographic literature; at higher latitudes the synoptic scale can be an order of magnitude larger than the deformation scale, which motivates our asymptotic approach and our nonstandard terminology. In the first model the synoptic dynamics are described by ‘Large Amplitude Geostrophic’ (LAG) equations while the eddy dynamics are quasigeostrophic. This model has order one isopycnal variation on the synoptic scale; the synoptic dynamics respond to an eddy momentum flux while the eddy dynamics respond to the baroclinically unstable synoptic density gradient. The second model assumes small isopycnal variation on the synoptic scale, but allows for a planetary scale background density gradient that may be fixed or evolved on a slower time scale. Here the large-scale equations are just the barotropic quasigeostrophic equations, and the mesoscale is modeled by the baroclinic quasigeostrophic equations. The synoptic dynamics now respond to both eddy momentum and buoyancy fluxes, but the small-scale eddy dynamics are simply advected by the synoptic-scale flow-there is no baroclinic production term in the eddy equations. The energy budget is closed by deriving an equation for the slow evolution of the eddy energy, which ensures that energy gained or lost by the synoptic-scale flow is reflected in a corresponding loss or gain by the eddies. This latter model, aided by the eddy energy equation-a key result of this paper-provides a conceptual basis through which to understand the classic baroclinic turbulence cycle.

  14. 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.

  15. 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.

  16. 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.

  17. Mesoscale Modelling of Westafrican Precipitation In Impetus Westafrica

    NASA Astrophysics Data System (ADS)

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

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

  18. 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...

  19. 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...

  20. Utilization of satellite data in mesoscale modeling of severe weather

    NASA Technical Reports Server (NTRS)

    Warner, Thomas T.

    1987-01-01

    The Visible Infrared Spin Scan Radiometer Atmospheric Sounder (VAS) data were used to model the 36 hour cyclogenesis period over the Pacific Ocean. Various combinations of VAS data, conventional radiosonde data, and gridded data from the National Weather Service global analysis were used in successive-correction and variational objective-analysis procedures. The Penn State/NCAR mesoscale model was used to test the impact of the VAS data on a 12 hour forecast of convective precipitation in the midweastern U.S.

  1. Mesoscale Modeling of the Atmosphere and Aerosols

    DTIC Science & Technology

    2000-09-30

    fires, or the dynamical and topographical forcing is small-scale, as in dust storms . A high-resolution COAMPS is needed to simulate the first stages of...context. However, the tightly coupled application is practical only for dynamically driven aerosols (e.g. dust storms ) or for planned (e.g. known...an imbedded aerosol module for COAMPS for use in the design and evaluation of techniques for coupling off-line transport and dispersion models to

  2. Mesoscale Model Microphysics and Rapid Hurricane Intensification

    NASA Astrophysics Data System (ADS)

    Meiselman, Ben Aaron

    Production of liquid water and subsequent evaporative cooling are important processes in the thermodynamic cycle of a hurricane. Allowing evaporative cooling in a hurricane simulation results in the development of a less intense hurricane than a simulation that removes evaporative cooling of precipitation (Wang 2002 and Pattnaik and Krishnamurti 2007) or evaporation of cloud water and precipitation (Zhu and Zhang 2006). In addition, the weight of liquid water within the eyewall updrafts of the storm may act to limit the eyewall updraft magnitudes (Zhang et al. 2000). In order to explore the effects of removing evaporative cooling and water loading, we use the "no cloud cloud model" (NCCM) of Fovell (2004). The NCCM microphysics formulation is based on the scheme of Kessler (1969) in which all hydrometeors are in liquid form. In NCCM, all condensate is removed upon its formation, thus preventing evaporative cooling and eliminating water loading effects. Using the Weather Research and Forecasting (WRF) model, Fovell and Su (2007) show that a NCCM-based storm both intensifies more rapidly than a Kessler microphysics storm and attains a peak intensity well in excess of that predicted by the Emanuel (1988) Maximum Potential Intensity (MPI) theory. In the present study, the mechanism for rapid intensification is explored utilizing the axisymmetric hurricane model of Rotunno and Emanuel (1987) and confirmed using the three dimensional WRF model. While larger upward velocities due to the lack of water loading are found to be a necessary ingredient in the onset of rapid intensification, this factor alone is not sufficient for any sustained intensification. Combined with the warming that is unchecked by evaporative cooling of the no evaporation storm, however, the lack of water loading contributes to the phenomenal intensification observed in the NCCM storm. This intensification is associated with downdrafts that flank the inside edge of the eyewall and result in significant

  3. 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.

  4. Mesoscale modeling of polyelectrolyte brushes with salt.

    PubMed

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

    2010-06-03

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

  5. 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.

  6. 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.

  7. An explicit mixed numerical method for mesoscale model

    NASA Technical Reports Server (NTRS)

    Hsu, H.-M.

    1981-01-01

    A mixed numerical method has been developed for mesoscale models. The technique consists of a forward difference scheme for time tendency terms, an upstream scheme for advective terms, and a central scheme for the other terms in a physical system. It is shown that the mixed method is conditionally stable and highly accurate for approximating the system of either shallow-water equations in one dimension or primitive equations in three dimensions. Since the technique is explicit and two time level, it conserves computer and programming resources.

  8. Three Dimensional Visualization of a Coastal Mesoscale Model

    DTIC Science & Technology

    1993-12-01

    thankful to Karen, my wife, who managed to keep the faith as well as grow a beautiful daughter, Danielle Tayler Sampson -- our first. Danielle, I ...No I I TITLE (include secutray class•ncarronii Three Dimensional Visualization of a Coastal Mesoscale Model 12 PERSONAl. AUTHOR(S) Sampson, R. Mark 1...3a TYPE OF REPORT 13b TIME COVERED 114 DATE OF REPORT (year, monA daiv; I PAGE COUN.NT Master’s Thesis Fr To 93 December 70 16 SUPPLEMENTARY NOTATION

  9. 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

  10. 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.

  11. Mesoscale modelling of crack-induced diffusivity in concrete

    NASA Astrophysics Data System (ADS)

    Nilenius, Filip; Larsson, Fredrik; Lundgren, Karin; Runesson, Kenneth

    2015-02-01

    Cracks have large impact on the diffusivity of concrete since they provide low-resistance pathways for moisture and chloride ions to migrate through the material. In this work, crack-induced diffusivity in concrete is modelled on the heterogeneous mesoscale and computationally homogenized to obtain macroscale diffusivity properties. Computations are carried out using the finite element method on three-dimensional statistical volume elements (SVEs) comprising the mesoscale constituents in terms of cement paste, aggregates and the interfacial transition zone (ITZ). The SVEs are subjected to uni-axial tension loading and cracks are simulated by use of an isotropic damage model. In a damaged finite element, the crack plane is assumed to be perpendicular to the largest principle strain, and diffusivity properties are assigned to the element only in the in-plane direction of the crack by anisotropic constitutive modelling. The numerical results show that the macroscale diffusivity of concrete can be correlated to the applied mechanical straining of the SVE and that the macroscale diffusivity increases mainly in the transversal direction relative to the axis of imposed mechanical straining.

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

    NASA Technical Reports Server (NTRS)

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

    1985-01-01

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

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

    NASA Technical Reports Server (NTRS)

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

    1985-01-01

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

  14. Anisotropic mesoscale eddy transport in ocean general circulation models

    NASA Astrophysics Data System (ADS)

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

    2014-11-01

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

  15. 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

  16. Nonlinear natural engine: model for thermodynamic processes in mesoscale systems

    SciTech Connect

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

    1985-12-01

    To develop intuition on the possible application of concepts from thermodynamic heat engines to mesoscale systems, the authors 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 x 10/sup 2/ 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. 19 references, 3 figures.

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

    PubMed

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

    1985-12-01

    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 x 10(2) 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.

  18. 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.

  19. 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.

  20. 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.

  1. New Approaches to the Parameterization of Gravity-Wave and Flow-Blocking Drag due to Unresolved Mesoscale Orography Guided by Mesoscale Model Predictability Research

    DTIC Science & Technology

    2012-09-30

    and Flow-Blocking Drag due to Unresolved Mesoscale Orography Guided by Mesoscale Model Predictability Research Stephen D. Eckermann Geospace ...5d. PROJECT NUMBER 5e. TASK NUMBER 5f. WORK UNIT NUMBER 7. PERFORMING ORGANIZATION NAME(S) AND ADDRESS(ES) Geospace Science & Technology Branch

  2. Mesoscale constitutive modeling of non-crystallizing filled elastomers

    NASA Astrophysics Data System (ADS)

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

    2016-04-01

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

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

    NASA Technical Reports Server (NTRS)

    Kalb, M. W.

    1984-01-01

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

  4. 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.

  5. Robust parametric models of runoff characteristics at the mesoscale

    NASA Astrophysics Data System (ADS)

    Samaniego, Luis; Bárdossy, András

    2005-03-01

    Many hydrologic studies report that runoff characteristics such as means or extremes of a given basin may be modified due to climatic and/or land use/cover changes and that the magnitude of these changes largely depends on the geographic location and the scale at which the study is carried out. Identifying the main causes of variability at the mesoscale, however, is a challenging task because of the lack of data regarding the spatial distribution of relevant explanatory variables and, if they exist, because of their high uncertainty. This study proposes a general method to find a robust non-linear model by solving a constrained multiobjective optimization problem whose solution space is composed of all feasible combinations of given explanatory variables. As a result, a model that simultaneously fulfills several criteria such as parsimony, robustness, significance, and overall performance is expected. Furthermore, it does not require assumptions regarding the sampling distributions neither of the parameters nor of the estimators because their p-values are estimated by a non-parametric technique. Finally, there is no limitation with respect to the functional form adopted for a given model and its estimator because a generalized reduced gradient algorithm is used for the calibration of its parameters. The proposed method was tested in the upper catchment of the Neckar River (Germany) covering an area of approximately 4000 km 2. The objective of this study was to detect trends and responses of runoff characteristics in mesoscale catchments due to changes of climatic or land use/cover conditions. In this case, the explained variables are the specific total discharge in summer and winter whereas the explanatory variables comprise several physiographic, land cover and climatic characteristics evaluated for 46 subcatchments during the period 1961-1993. The results of the study indicate a significant gain in performance and robustness of the selected models compared to

  6. 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.

  7. 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.

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

    NASA Astrophysics Data System (ADS)

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

    2015-02-01

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

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

    NASA Astrophysics Data System (ADS)

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

    2007-07-01

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

  10. Implementation of Modeling the Land-Surface/Atmosphere Interactions to Mesoscale Model COAMPS

    DTIC Science & Technology

    2012-09-30

    1 DISTRIBUTION STATEMENT A. Approved for public release; distribution is unlimited. Implementation of Modeling the Land-Surface/Atmosphere...Interactions to Mesoscale Model COAMPS Dr. Bogumil Jakubiak Interdisciplinary Centre for Mathematical and Computational Modelling , Warsaw...Interdisciplinary Centre for Mathematical and Computational Modelling , Warsaw University, Pawinskiego 5A, 02-106 Warsaw, Poland phone: +48-22-8749-144 fax

  11. 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

  12. 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

  13. 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

  14. 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.

  15. 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

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

    PubMed Central

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

    2013-01-01

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

  17. 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

  18. Air Pollution Modeling Using A 3-d Hemispheric Nested Model

    NASA Astrophysics Data System (ADS)

    Frohn, L. M.; Christensen, J. H.; Brandt, J.; Hertel, O.

    A 3-D Eulerian transport-chemistry model based on modules and parameterisations from models developed over the last decade at the National Environmental Research Institute (DREAM, DEHM, ACDEP and DEOM) has been developed. The model is hemispheric with currently two nests implemented. The horizontal resolution in the mother domain is 150 km x 150 km. First nest covers the European area wit,h a 50 km x 50 km resolution, second covers the Scandinavian area with a resolution of 16.67 km x 16.67 km. The model employs a chemical scheme (originally 53 species) which has been modified to include a detailed description of the nitrogen chemistry. The concentration of air pollutants, such as sulfur and nitrogen in various forms, has been calculated with the model, applying no nesting as well as one and two nests. The calculated values have been validated by comparison to measurements from more than 200 EMEP monitoring stations. Furthermore deposition of nitrogen to marine waters has been estimated with the model. The goal is to obtain an improved description of spatial and temporal variations in the nutrient deposition to the marine environment. In the presentation the physics and chemistry of the model will be shortly described. Validations of the model calculations by comparison to EMEP measurements will be shown and discussed together with the results of the deposition calculations.

  19. 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

  20. 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).

  1. Random-forcing model of the mesoscale oceanic eddies

    NASA Astrophysics Data System (ADS)

    Berloff, Pavel S.

    2005-04-01

    The role of mesoscale oceanic eddies in driving large-scale currents is studied in an eddy-resolving midlatitude double-gyre ocean model. The reference solution is decomposed into large-scale and eddy components in a way which is dynamically consistent with a non-eddy-resolving ocean model. That is, the non-eddy-resolving solution driven by this eddy-forcing history, calculated on the basis of this decomposition, correctly approximates the original flow. The main effect of the eddy forcing on the large-scale flow is to enhance the eastward-jet extension of the subtropical western boundary current. This is an anti-diffusive process, which cannot be represented in terms of turbulent diffusion. It is shown that the eddy-forcing history can be approximated as a space-time correlated, random-forcing process in such a way that the non-eddy-resolving solution correctly approximates the reference solution. Thus, the random-forcing model can potentially replace the diffusion model, which is commonly used to parameterize eddy effects on the large-scale currents. The eddy-forcing statistics are treated as spatially inhomogeneous but stationary, and the dynamical roles of space-time correlations and spatial inhomogeneities are systematically explored. The integral correlation time, oscillations of the space correlations, and inhomogeneity of the variance are found to be particularly important for the flow response.

  2. 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.

  3. Numerical Simulations of the Wintertime Optical Turbulence in Antarctica with the Mesoscale Model Meso-Nh

    NASA Astrophysics Data System (ADS)

    Lascaux, F.; Masciadri, E.; Hagelin, S.; Stoesz, J.

    2009-09-01

    Mesoscale model such as Meso-NH have proven to be highly reliable in reproducing 3D maps of optical turbulence (OT).1-3 These last years ground-based astronomy has been looking towards Antarctica, especially its summits and the continental plateau where the OT appears to be confined in a shallow layer close to the surface. However some uncertainties remain. That's why our group is focusing on a detailed study of the atmospheric flow and turbulence in the internal Antarctic Plateau. Our intention in this study is to use the Meso-NH model to do predictions of the atmospheric flow in the internal plateau. The use of this model permits us to have access to informations inside an entire 3D volume, which is not the case with observations only. Two different configurations of the model have been used: one with a low horizontal resolution (ΔX = 100 km) and another one with higher horizontal resolution with the help of the grid-nesting interactive technique (ΔX = 1 km in the innermost domain). The impact of the configuration on the meteorological parameters has already been studied.4 We present here the results obtained with Meso-Nh of forecasted CN2 profiles, surface layer thickness (SLT) and seeing values at Dome C for the 16 winter nights, whose CN2 profiles have been measured by Ref.5.

  4. Dynamically consistent parameterization of mesoscale eddies. Part I: Simple model

    NASA Astrophysics Data System (ADS)

    Berloff, Pavel

    2015-03-01

    This work aims at developing a framework for dynamically consistent parameterization of mesoscale eddy effects for use in non-eddy-resolving ocean circulation models. The proposed eddy parameterization framework is successfully tested on the classical, wind-driven double-gyre model, which is solved both with explicitly resolved vigorous eddy field and in the non-eddy-resolving configuration with the eddy parameterization replacing the eddy effects. The parameterization locally approximates transient eddy flux divergence by spatially localized and temporally periodic forcing, referred to as the plunger, and focuses on the linear-dynamics flow solution induced by it. The nonlinear self-interaction of this solution, referred to as the footprint, characterizes and quantifies the induced cumulative eddy forcing exerted on the large-scale flow. We find that spatial pattern and amplitude of the footprint strongly depend on the underlying large-scale and the corresponding relationships provide the basis for the eddy parameterization and its closure on the large-scale flow properties. Dependencies of the footprints on other important parameters of the problem are also systematically analyzed. The parameterization utilizes the local large-scale flow information, constructs and scales the corresponding footprints, and then sums them up over the gyres to produce the resulting eddy forcing field, which is interactively added to the model as an extra forcing. The parameterization framework is implemented in the simplest way, but it provides a systematic strategy for improving the implementation algorithm.

  5. Mesoscale Phase Field Modeling of Glass Strengthening Under Triaxial Compression

    SciTech Connect

    Li, Yulan; Sun, Xin

    2015-09-28

    Recent hydraulic bomb and confined sleeve tests on transparent armor glass materials such as borosilicate glass and soda-lime glass showed that the glass strength was a function of confinement pressure. The measured stress-strain relation is not a straight line as most brittle materials behave under little or no confinement. Moreover, borosilicate glass exhibited a stronger compressive strength when compared to soda-lime glass, even though soda-lime has higher bulk and shear moduli as well as apparent yield strength. To better understand these experimental findings, a mesoscale phase field model is developed to simulate the nonlinear stress versus strain behaviors under confinement by considering heterogeneity formation under triaxial compression and the energy barrier of a micro shear banding event (referred to as pseudo-slip hereafter) in the amorphous glass. With calibrated modeling parameters, the simulation results demonstrate that the developed phase field model can quantitatively predict the pressure-dependent strength, and it can also explain the difference between the two types of glasses from the perspective of energy barrier associated with a pseudo-slip event.

  6. 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.

  7. 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.

  8. Probabilistic flood damage modelling at the meso-scale

    NASA Astrophysics Data System (ADS)

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

    2014-05-01

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

  9. 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.

  10. Using dispersion and mesoscale meteorological models to forecast pollen concentrations

    NASA Astrophysics Data System (ADS)

    Pasken, Robert; Pietrowicz, Joseph A.

    This work describes the results of research into a source-oriented pollen concentration forecasting technique. Tests were conducted using the National Center for Atmospheric Research/ Penn State Fifth Generation Mesoscale Model (MM5), the National Oceanographic and Atmospheric Administration (NOAA) Hybrid Single-Particle Lagrangian Integrated Trajectory (HYSPLIT_4) Model combined with the locations of oak trees and their aerial coverage from biogenic emissions land cover database version 3.1 (BELD3). Daily forecasts of pollen concentrations via MM5 and HYSPLIT_4 were made with 30-min increments and tested against 30-min oak pollen data collected by the St. Louis County Department of Health in Clayton, Missouri, for the month of April 2000. Results from these tests show that the combination of MM5 and HYSPLIT_4 with accurate source locations can provide short-term forecasts as indicated by the levels of forecast pollen and actual oak pollen levels, which follow similar profiles for the day. From the 30 individual pollen concentration forecasts, two example forecasts are presented. Additional studies need to be conducted to further validate these results, using an array of pollen collectors. A better understanding of the biology of pollen release is critical to improving these pollen concentration forecasts.

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

    DOE PAGES

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

    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. 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...

  15. 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

  16. A hybrid wind farm parameterization for mesoscale and climate models

    NASA Astrophysics Data System (ADS)

    Pan, Y.; Archer, C. L.

    2016-12-01

    To better understand the potential impacts of wind farms on weather and climate at the local to regional scale, a new hybrid wind farm parameterization is proposed here for mesoscale models, such as the Weather Research and Forecasting Model (WRF), or climate models, such as the Community Atmosphere Model (CAM). All previous wind farm parameterizations treat all the wind turbines in the same grid cell as identical (i.e., they all share the same upstream wind velocity) and ignore the effect of wind direction. By contrast, the new hybrid model considers each individual wind turbine, based on its position in the layout and on wind direction. The new parameterization is developed starting from large eddy simulations (LES) of existing wind farms, in which the local flow around each wind turbine is directly simulated at high spatial ( 3.5 m) and temporal ( 0.1 s) resolutions and the effects of subgrid-scale processes are modeled. Based on analytic and statistical relationships between the LES results and several geometric properties of the wind farm layout (such as blockage ratio and blocking distance), the new hybrid parameterization predicts the local upstream wind speed of each individual wind turbine in the same grid cell, and thus successfully account for the effects of layout and wind direction with little computational cost. With the newly predicted upstream velocity, the turbine-induced forces and added turbulence kinetic energy (TKE) in the atmosphere are derived analytically. The wind speed, wind speed deficit, and TKE profiles and power production obtained with the hybrid parameterization for the test case (the 48-turbine Lillgrund wind farm in Sweden) are in better agreement with the LES results than previous parameterizations. Future work includes the insertion of the hybrid parameterization into the WRF code to assess impacts on near-surface properties, such as temperature and heat and momentum fluxes, in the region surrounding the wind farm.

  17. 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

  18. Meso-Scale Radioactive Dispersion Modelling using GPU

    NASA Astrophysics Data System (ADS)

    Sunarko; Suud, Zaki

    2017-01-01

    Lagrangian Particle Dispersion Method (LPDM) is applied to model atmospheric dispersion of radioactive material in a meso-scale of a few tens of kilometers for site study purpose. Empirical relationships are used to determine the dispersion coefficient for various atmospheric stabilities. Diagnostic 3-D wind field is created based on data from a meteorological station using mass-conservation principle. Particles imitating radioactive pollutant are dispersed in the wind-field as a point source. Time-integrated air concentration is calculated using kernel density estimator (KDE) in the lowest layer of the atmosphere. Parallel code is developed for GTX-660Ti GPU with a total of 1344 scalar processors using CUDA programming. Significant speedup of about 20 times is achieved compared to the serial version of the code while accuracy is kept at reasonable level. Only small differences in particle positions and grid doses are observed when using the same sets of random number and meteorological data in both CPU and GPU versions of the code.

  19. Modeling of Mesoscale Variability in Biofilm Shear Behavior

    PubMed Central

    Barai, Pallab; Kumar, Aloke; Mukherjee, Partha P.

    2016-01-01

    Formation of bacterial colonies as biofilm on the surface/interface of various objects has the potential to impact not only human health and disease but also energy and environmental considerations. Biofilms can be regarded as soft materials, and comprehension of their shear response to external forces is a key element to the fundamental understanding. A mesoscale model has been presented in this article based on digitization of a biofilm microstructure. Its response under externally applied shear load is analyzed. Strain stiffening type behavior is readily observed under high strain loads due to the unfolding of chains within soft polymeric substrate. Sustained shear loading of the biofilm network results in strain localization along the diagonal direction. Rupture of the soft polymeric matrix can potentially reduce the intercellular interaction between the bacterial cells. Evolution of stiffness within the biofilm network under shear reveals two regimes: a) initial increase in stiffness due to strain stiffening of polymer matrix, and b) eventual reduction in stiffness because of tear in polymeric substrate. PMID:27806068

  20. Simulating mesoscale transport and diffusion of radioactive noble gases using the Lagrangian particle dispersion model.

    PubMed

    Kim, Cheol-Hee; Song, Chang-Keun; Lee, Sang-Hyun; Song, Sang-Keun

    2008-10-01

    In order to simulate the impact of mesoscale wind fields and to assess potential capability of atmospheric Lagrangian particle dispersion model (LPDM) as an emergency response model for the decision supports, two different simulations of LPDM with the mesoscale prognostic model MM5 (Mesoscale Model ver. 5) were driven. The first simulation of radioactive noble gas (85Kr exponent) emitted during JCO accident occurred from 30 September to 3 October 1999 at Tokai, Japan showed that the first arriving short pulse was found in Tsukuba located at 60 km away from the accidental area. However, the released radioactive noble gas was transported back to the origin site about 2 days later due to the mesoscale meteorological wind circulation, enhancing the levels of 85Kr with the secondary peak in Tsukuba. The second simulation of atmospheric dilution factors (the ratio of concentration to the emission rate, chi/Q), during the underground nuclear test (UNT) performed by North Korea showed that high chi/Q moved to the eastward and extended toward southward in accordance with the mesoscale atmospheric circulations generated by mesoscale prognostic model MM5. In comparison with the measurements, the simulated horizontal distribution patterns of 85Kr during the JCO are well accord with that of observation in Tsukuba such as the existence of secondary peak which is associated with the mesoscale circulations. However, the simulated level of 85Kr anomaly was found to be significantly lower than the observations, and some interpretations on these discrepancies were described. Applications of LPDM to two mesoscale emergency response dispersion cases suggest the potential capability of LPDM to be used as a decision support model provided accurate emission rate of accident in case of a large accident.

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

    NASA Astrophysics Data System (ADS)

    Munters, Wim; Meneveau, Charles; Meyers, Johan

    2014-11-01

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

  2. Initializing a Mesoscale Boundary-Layer Model with Radiosonde Observations

    NASA Astrophysics Data System (ADS)

    Berri, Guillermo J.; Bertossa, Germán

    2017-08-01

    A mesoscale boundary-layer model is used to simulate low-level regional wind fields over the La Plata River of South America, a region characterized by a strong daily cycle of land-river surface-temperature contrast and low-level circulations of sea-land breeze type. The initial and boundary conditions are defined from a limited number of local observations and the upper boundary condition is taken from the only radiosonde observations available in the region. The study considers 14 different upper boundary conditions defined from the radiosonde data at standard levels, significant levels, level of the inversion base and interpolated levels at fixed heights, all of them within the first 1500 m. The period of analysis is 1994-2008 during which eight daily observations from 13 weather stations of the region are used to validate the 24-h surface-wind forecast. The model errors are defined as the root-mean-square of relative error in wind-direction frequency distribution and mean wind speed per wind sector. Wind-direction errors are greater than wind-speed errors and show significant dispersion among the different upper boundary conditions, not present in wind speed, revealing a sensitivity to the initialization method. The wind-direction errors show a well-defined daily cycle, not evident in wind speed, with the minimum at noon and the maximum at dusk, but no systematic deterioration with time. The errors grow with the height of the upper boundary condition level, in particular wind direction, and double the errors obtained when the upper boundary condition is defined from the lower levels. The conclusion is that defining the model upper boundary condition from radiosonde data closer to the ground minimizes the low-level wind-field errors throughout the region.

  3. Analysis of a Mesoscale Model for Depicting Rain-on-Snow Flooding Events in Mountainous Terrain

    NASA Astrophysics Data System (ADS)

    Morehead, M. D.; Dawson, P.; Seyfried, M. S.

    2002-12-01

    Cold season rain-on-snow events are one of the major sources of flooding in the Pacific Northwest. Accurate modeling of the atmospheric fields forcing these events is leading to a better understanding of the atmospheric conditions behind these events and to better prediction of these floods. A mesoscale atmospheric model (RAMS) with nested grids is being used for high resolution simulations of winter precipitation and other climate variables in the Owyhee mountains of southwestern Idaho. The Reynolds Creek Experimental Watershed (RCEW) contains a dense array of meteorologic and hydrologic instrumentation with which to test the spatial and temporal hydrologic and atmospheric models. The large number of precipitation gauges in the RCEW cover a wide range of precipitation zones found in mountainous terrain. These gauges allow for a thorough assessment of the areal distribution and timing of modeled versus measured precipitation and temperature. A comparison of the modeled and measured data from two winter storms associated with rain-on-snow events shows close agreement in the spatial and temporal distributions of precipitation, temperature and other variables. The model correctly predicts the spatial distribution of precipitation and the temporal conversion from snow to rain-on-snow in the lower elevations of the watershed. The modeled precipitation is typically slightly lower than the measured values. Some of the high frequency (hourly) weather variability was not captured by the model, presumably due to lack of sufficient data in the initialization process. The longer term goal is to develop a tool for generating detailed weather information for winter time hydrologic studies including cold season flooding processes and to better understand the processes controlling winter flooding.

  4. 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

  5. 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.

  6. Mesoscale modeling study of severe convection over complex terrain

    NASA Astrophysics Data System (ADS)

    Zhang, Ying; Meng, Zhiyong; Zhu, Peijun; Su, Tao; Zhai, Guoqing

    2016-11-01

    Short squall lines that occurred over Lishui, southwestern Zhejiang Province, China, on 5 July 2012, were investigated using the WRF model based on 1°×1° gridded NCEP Final Operational Global Analysis data. The results from the numerical simulations were particularly satisfactory in the simulated radar echo, which realistically reproduced the generation and development of the convective cells during the period of severe convection. The initiation of this severe convective case was mainly associated with the uplift effect of mesoscale mountains, topographic convergence, sufficient water vapor, and enhanced low-level southeasterly wind from the East China Sea. An obvious wind velocity gradient occurred between the Donggong Mountains and the southeast coastline, which easily enabled wind convergence on the windward slope of the Donggong Mountains; both strong mid-low-level southwesterly wind and low-level southeasterly wind enhanced vertical shear over the mountains to form instability; and a vertical coupling relation between the divergence on the upper-left side of the Donggong Mountains and the convergence on the lower-left side caused the convection to develop rapidly. The convergence centers of surface streams occurred over the mountain terrain and updrafts easily broke through the lifting condensation level (LCL) because of the strong wind convergence and topographic lift, which led to water vapor condensation above the LCL and the generation of the initial convective cloud. The centers of surface convergence continually created new convective cells that moved with the southwest wind and combined along the Donggong Mountains, eventually forming a short squall line that caused severe convective weather.

  7. 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

  8. 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.

  9. Applying horizontal diffusion on pressure surface to mesoscale models on terrain-following coordinates

    Treesearch

    Hann-Ming Henry Juang; Ching-Teng Lee; Yongxin Zhang; Yucheng Song; Ming-Chin Wu; Yi-Leng Chen; Kevin Kodama; Shyh-Chin Chen

    2005-01-01

    The National Centers for Environmental Prediction regional spectral model and mesoscale spectral model (NCEP RSM/MSM) use a spectral computation on perturbation. The perturbation is defined as a deviation between RSM/MSM forecast value and their outer model or analysis value on model sigma-coordinate surfaces. The horizontal diffusion used in the models applies...

  10. 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.

  11. 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.

  12. 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

  13. Modeling Fluctuating Winds by Blending Mesoscale Model Data with Computational Fluid Dynamics (Invited)

    NASA Astrophysics Data System (ADS)

    Haupt, S. E.; Zajaczkowski, F. J.; Schmehl, K. J.

    2010-12-01

    Wind energy companies require information regarding details of the wind field for both micrositing new wind farms and the specific turbines within them as well as for forecasting power production at particular sites. Although Numerical Weather Prediction (NWP) models applied on the mesoscale can provide information regarding the general flow characteristics, the very fine scale details (on the order of meters to tens of meters) dependent on local features are not available. That is precisely the realm in which Computational Fluid Dynamics (CFD) models excel. These CFD models are capable of capturing details of the boundary layer dynamics and turbulent structures over a finer range of scales as well as flow around features such as buildings. They are not generally configured, however, to include radiation, moist convection physics, land surface parameterizations, and other physics packages commonly available within the NWP models. The solution proposed here is to blend the information provided by the mesoscale NWP models with the details of CFD by assimilating the NWP data directly into the CFD model. The assimilation occurs both at the boundaries as an inflow condition for the CFD model and internally by assimilating an NWP wind and temperature profile at the vertical gridlines of the mesoscale model run. This internal assimilation uses the Newtonian Relaxation technique, in which the solution is nudged toward the mesoscale values in the vicinity of the grid line while maintaining the internal mass and momentum consistency of the CFD model. The assimilation blending technique is demonstrated in the Rock Springs valley nestled between rolling ridges in the central Pennsylvania countryside in the vicinity of several wind farms. Two specific case days are chosen to represent typical summer and winter characteristics. The WRF-ARW NWP model is run with four dimensional data assimilation to produce a 1.3 km resolution mesoscale analysis. That data provide the basis for

  14. 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…

  15. 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.

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

    NASA Astrophysics Data System (ADS)

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

    2009-12-01

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

  17. 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.

  18. 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.

  19. Modeling nest survival of cavity-nesting birds in relation to postfire salvage logging

    Treesearch

    Vicki Saab; Robin E. Russell; Jay Rotella; Jonathan G. Dudley

    2011-01-01

    Salvage logging practices in recently burned forests often have direct effects on species associated with dead trees, particularly cavity-nesting birds. As such, evaluation of postfire management practices on nest survival rates of cavity nesters is necessary for determining conservation strategies. We monitored 1,797 nests of 6 cavity-nesting bird species: Lewis'...

  20. 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.

  1. The US DOE A2e Mesoscale to Microscale Coupling Project: Nonstationary Modeling Techniques and Assessment

    NASA Astrophysics Data System (ADS)

    Haupt, Sue Ellen; Kosovic, Branko; Shaw, William

    2017-04-01

    The purpose of the US DOE's Mesoscale-Microscale Coupling (MMC) Project is to develop, verify, and validate physical models and modeling techniques that bridge the most important atmospheric scales that determine wind plant performance and reliability. As part of DOE's Atmosphere to Electrons (A2e) program, the MMC project seeks to create a new predictive numerical simulation capability that is able to represent the full range of atmospheric flow conditions impacting wind plant performance. The recent focus of MMC has been on nonstationary conditions over flat terrain. These nonstationary cases are critical for wind energy and represent a primary need for mesoscale meteorological forcing of the microscale models. The MMC team modeled two types of non-stationary cases: 1) diurnal cycles in which the daytime convective boundary layer collapses with the setting of the sun when the surface heat flux changes from positive to negative, passing through a brief period of neutral stability before becoming stable, with smaller scale turbulence and the potential for low level jet (LLJ) formation; and 2) frontal passage as an example of a synoptic weather event that may cause relatively rapid changes in wind speed and direction. The team compared and contrasted two primary techniques for non-stationary forcing of the microscale by the mesoscale model. The first is to use the tendencies from the mesoscale model to directly force the microscale mode. The second method is to couple not only the microscale domain's internal forcing parameters, but also its lateral boundaries, to a mesoscale simulation. While the boundary coupled approach provides the greatest generality, since the mesoscale flow information providing the lateral boundary information for the microscale domain contains no explicit turbulence information, the approach requires methods to accelerate turbulence production at the microscale domain's inflow boundaries. Forefront assessment strategies, including comparing

  2. An Application of an Explicit Microphysics Mesoscale Model to a Regional Icing Event

    DTIC Science & Technology

    1994-03-24

    in the production of SLW 10 0 . ...330 - 14 .r0 -0 _/ _I " \\.1". 1, . " X ",• " F I " i . 13 L S s u d n tak en .at. W i g n C o o r d , at, .. 2.. U T...FNCN 1JLNBE.RS :An Application of an Explicit Microphysics MesoscaleModel to a Regional Icing Event PE 61102F PR 2310 S6. AUTHOR(S) TA G7 George D ...1994 American MWcoOkocal Society An Application of an Explicit Microphysics Mesoscale Model to a Regional Icing Event GEORGE D . MODICA AND SCOT T

  3. The evolution of the mesoscale environment of severe local storms Preliminary modeling results

    NASA Technical Reports Server (NTRS)

    Anthes, R. A.; Kuo, Y.-H.; Benjamin, S. G.; Li, Y.-F.

    1982-01-01

    A mesoscale model is employed for predicting two severe weather events observed during thy 1979 SESAME field programs. Particular attention is given to the development and decay of a low-level jet, to the formation of a mesoscale convective complex (MCC) and its modification of lower- and upper-level circulation, to the formation of mesoscale regions of heavy precipitation, the intensification of surface warm and cold fronts, the formation of drylines, dynamic coupling of upper- and low-level jets, the formation of a mountain wave, and the formation and maintenance of capping inversions. A summary of the physics and parameters of a tornado outbreak and a heavy precipitation event are given for a simple bulk-PBL formulation with no heating. A ten-layer model was demonstrated to be sufficient for generating and maintaining distinct vertical gradients of temperature, moisture, and wind across low-level inversions.

  4. 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.

  5. 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.

  6. Eddy Effects in the General Circulation, Spanning Mean Currents, Mesoscale Eddies, and Topographic Generation, Including Submesoscale Nests

    DTIC Science & Technology

    2014-09-30

    Alexander F. Shchepetkin (PI) James C. McWilliams and Maarten J. Molemaker (Co-PIs) Department of Atmospheric and Oceanic Sciences University of...LONG-TERM GOALS Our goals are the continuing development of the Regional Oceanic Modeling System (ROMS) with emphasis on the ability to simulate... Oceanic Sciences,Los Angeles,CA,90095 8. PERFORMING ORGANIZATION REPORT NUMBER 9. SPONSORING/MONITORING AGENCY NAME(S) AND ADDRESS(ES) 10. SPONSOR

  7. 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.

  8. Evaluation of scale-aware subgrid mesoscale eddy models in a global eddy-rich model

    NASA Astrophysics Data System (ADS)

    Pearson, Brodie; Fox-Kemper, Baylor; Bachman, Scott; Bryan, Frank

    2017-07-01

    Two parameterizations for horizontal mixing of momentum and tracers by subgrid mesoscale eddies are implemented in a high-resolution global ocean model. These parameterizations follow on the techniques of large eddy simulation (LES). The theory underlying one parameterization (2D Leith due to Leith, 1996) is that of enstrophy cascades in two-dimensional turbulence, while the other (QG Leith) is designed for potential enstrophy cascades in quasi-geostrophic turbulence. Simulations using each of these parameterizations are compared with a control simulation using standard biharmonic horizontal mixing.Simulations using the 2D Leith and QG Leith parameterizations are more realistic than those using biharmonic mixing. In particular, the 2D Leith and QG Leith simulations have more energy in resolved mesoscale eddies, have a spectral slope more consistent with turbulence theory (an inertial enstrophy or potential enstrophy cascade), have bottom drag and vertical viscosity as the primary sinks of energy instead of lateral friction, and have isoneutral parameterized mesoscale tracer transport. The parameterization choice also affects mass transports, but the impact varies regionally in magnitude and sign.

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

    NASA Technical Reports Server (NTRS)

    Chen, Chaing

    1991-01-01

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

  10. 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.

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

    NASA Astrophysics Data System (ADS)

    Westhoff, Martijn; Zehe, Erwin

    2014-05-01

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

  12. Mesoscale atmospheric modelling technology as a tool for the long-term meteorological dataset development

    NASA Astrophysics Data System (ADS)

    Platonov, Vladimir; Kislov, Alexander; Rivin, Gdaly; Varentsov, Mikhail; Rozinkina, Inna; Nikitin, Mikhail; Chumakov, Mikhail

    2017-04-01

    The detailed hydrodynamic modelling of meteorological parameters during the last 30 years (1985 - 2014) was performed for the Okhotsk Sea and the Sakhalin island regions. The regional non-hydrostatic atmospheric model COSMO-CLM used for this long-term simulation with 13.2, 6.6 and 2.2 km horizontal resolutions. The main objective of creation this dataset was the outlook of the investigation of statistical characteristics and the physical mechanisms of extreme weather events (primarily, wind speed extremes) on the small spatio-temporal scales. COSMO-CLM is the climate version of the well-known mesoscale COSMO model, including some modifications and extensions adapting to the long-term numerical experiments. The downscaling technique was realized and developed for the long-term simulations with three consequent nesting domains. ERA-Interim reanalysis ( 0.75 degrees resolution) used as global forcing data for the starting domain ( 13.2 km horizontal resolution), then these simulation data used as initial and boundary conditions for the next model runs over the domain with 6.6 km resolution, and similarly, for the next step to 2.2 km domain. Besides, the COSMO-CLM model configuration for 13.2 km run included the spectral nudging technique, i.e. an additional assimilation of reanalysis data not only at boundaries, but also inside the whole domain. Practically, this computational scheme realized on the SGI Altix 4700 supercomputer system in the Main Computer Center of Roshydromet and used 2,400 hours of CPU time total. According to modelling results, the verification of the obtained dataset was performed on the observation data. Estimations showed the mean error -0.5 0C, up to 2 - 3 0C RMSE in temperature, and overestimation in wind speed (RMSE is up to 2 m/s). Overall, analysis showed that the used downscaling technique with applying the COSMO-CLM model reproduced the meteorological conditions, spatial distribution, seasonal and synoptic variability of temperature and

  13. Modelling the Shock Response of Polycrystals at the Mesoscale

    NASA Astrophysics Data System (ADS)

    Case, Simon; Horie, Yuki

    2006-07-01

    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 14μm 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 0.4μm at a propagation distance of 80μm.

  14. 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

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

    NASA Astrophysics Data System (ADS)

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

    2013-04-01

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

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

    NASA Astrophysics Data System (ADS)

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

    2014-12-01

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

  17. 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

  18. 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

  19. Mesoscale magnetism

    DOE PAGES

    Hoffmann, Axel; Schultheiß, Helmut

    2014-12-17

    Magnetic interactions give rise to a surprising amount of complexity due to the fact that both static and dynamic magnetic properties are governed by competing short-range exchange interactions and long-range dipolar coupling. Even though the underlying dynamical equations are well established, the connection of magnetization dynamics to other degrees of freedom, such as optical excitations, charge and heat flow, or mechanical motion, make magnetism a mesoscale research problem that is still wide open for exploration. Synthesizing magnetic materials and heterostructures with tailored properties will allow to take advantage of magnetic interactions spanning many length-scales, which can be probed with advancedmore » spectroscopy and microscopy and modeled with multi-scale simulations. Finally, this paper highlights some of the current basic research topics in mesoscale magnetism, which beyond their fundamental science impact are also expected to influence applications ranging from information technologies to magnetism based energy conversion.« less

  20. Mesoscale magnetism

    SciTech Connect

    Hoffmann, Axel; Schultheiß, Helmut

    2014-12-17

    Magnetic interactions give rise to a surprising amount of complexity due to the fact that both static and dynamic magnetic properties are governed by competing short-range exchange interactions and long-range dipolar coupling. Even though the underlying dynamical equations are well established, the connection of magnetization dynamics to other degrees of freedom, such as optical excitations, charge and heat flow, or mechanical motion, make magnetism a mesoscale research problem that is still wide open for exploration. Synthesizing magnetic materials and heterostructures with tailored properties will allow to take advantage of magnetic interactions spanning many length-scales, which can be probed with advanced spectroscopy and microscopy and modeled with multi-scale simulations. Finally, this paper highlights some of the current basic research topics in mesoscale magnetism, which beyond their fundamental science impact are also expected to influence applications ranging from information technologies to magnetism based energy conversion.

  1. 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.

  2. 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.

  3. Mitigating Excessive Drying From the Use of Observations in Mesoscale Modeling

    DTIC Science & Technology

    2014-01-01

    Temperature. Mon. Wea. Rev., 1980, 180, 1046–1053. Chen, F.; Dudhia, J. Coupling an Advanced Land-Surface/ Hydrology Model with the Penn State/NCAR MM5...National Operational Hydrologic Remote Sensing Center NOAA National Oceanic and Atmospheric Administration RRTM Rapid Radiative Transfer Model ...Mitigating Excessive Drying From the Use of Observations in Mesoscale Modeling by Brian P. Reen, Robert E. Dumais, Jr., and Jeffrey E

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

    SciTech Connect

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

    1982-11-01

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

  5. 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

  6. 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

  7. 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.

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

    SciTech Connect

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

    1996-01-01

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

  9. 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)

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

    NASA Astrophysics Data System (ADS)

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

    2016-10-01

    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.

  11. A simplified mesoscale model for predicting the mechanical behavior of stitched CFRP laminates

    NASA Astrophysics Data System (ADS)

    Li, Jun; Wang, Bo; Jiao, Guiqiong

    2017-06-01

    This paper presents a finite element (FE) analysis of the mechanical responses for stitched CFRP laminates under different mechanical loads. Firstly, the through-thickness stitch was simplified to z-pin like reinforcement with a uniform displacement constraint on the upper and lower surfaces of the laminate. Then, a mesoscale 3D representative volume element (RVE) of the stitched composite was proposed and modeled in the FE code ABAQUS, where the reinforcing stitch, composite layers and interfaces were built. A 3D Hashin damage model and built-in cohesive elements were respectively used to predict the mechanical failure of the stitch and the damageable behavior of cohesive interfaces. Simulation results reveal the progressive damage and rupture processes of the RVE under tensile and shear mechanical loads, and macroscopic nonlinear load-displacement responses of the mesoscale model are also captured.

  12. 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.

  13. Nest survival in dusky Canada geese (Branta canadensis occidentalis): Use of discrete-time models

    USGS Publications Warehouse

    Grand, J.B.; Fondell, T.F.; Miller, D.; Anthony, R. Michael

    2006-01-01

    The Dusky Canada Goose (Branta canadensis occidentalis) population that breeds in the Copper River Delta, Alaska, has declined substantially since the late 1970s. Persistent low numbers have been attributed to low productivity in recent years. We examined patterns in survival rates of 1,852 nests to better understand ecological processes that influenced productivity during 1997-2000. We compared 10 nonparametric models of daily survival rate of nests (DSR) that included variation among years, calendar dates, nest initiation dates, and nest ages with equivalent models based on parametric functions. The unequivocal best model included patterns of DSR that varied among discrete periods of years, calendar dates, and nest ages. Generally, DSR was low early in the nesting season and higher midseason. Across years, patterns in DSR were most variable early and late in the nesting season. Daily survival rates of nests declined between the first and second week after initiation, increased until the fourth week, and then declined during the last week before hatch. Nest survival probability estimates ranged from 0.07 to 0.71 across years and nest initiation dates. Mean rates of nest survival ranged between 0.21 and 0.31 each year. We suggest (1) considering models that do not limit estimates of daily nest survival to parametric forms; (2) placing greater emphasis on sample size when nests are rare, to obtain accurate estimates of nest survival; and (3) developing new techniques to estimate the number of nests initiated.

  14. Combining Machine Learning and Mesoscale Modeling for Atmospheric Releases Hazard Assessment

    NASA Astrophysics Data System (ADS)

    Cervone, G.; Franzese, P.; Ezber, Y.; Boybeyi, Z.

    2007-12-01

    In applications such as homeland security and hazards response, it is necessary to know in real time which areas are most at risk from a potentially harmful atmospheric pollutant. Using high resolution remote sensing measurements and atmospheric mesoscale numerical models, it is possible to detect and study the transport and dispersion of particles with great accuracy, and to determine the ground concentrations which might pose a threat to people and properties. Satellite observations from different sensors must be fused together to compensate for different spatial, temporal and spectral resolutions and data availability. Such observations are used to initialize and validate atmospheric mesoscale models, which can provide accurate estimates of ground concentrations. Such numerical models are, however, usually slow due to the complex nature of the computations, and do not provide real time answers. We will define probability maps of risks by running several atmospheric mesoscale and T&D simulations spanning the climatological input conditions of an entire year, observed using high resolution remote sensing instruments. Such maps provide an immediate risk assessment area associated with a given source location. If a release indeed occurs, the computed risk maps can be used for first assessment and rapid response. We analyze the output of the mesoscale model runs using machine learning algorithms to find characteristic patterns which relate potential risk areas with atmospheric parameters which can be observed using remote sensing instruments and ground measurements. Therefore, when a release occurs, it is possible to give a quick hazard assessment without running a time consuming model, but by comparing the current atmospheric conditions with those associated with each identified risk area. The offline learning provides knowledge that can later be used to protect people and properties.

  15. 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.

  16. 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.

  17. 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

  18. Mesoscale circulations in the Los Angeles Basin: A numerical modeling study

    SciTech Connect

    Ulrickson, B.L.

    1988-01-01

    Mesoscale atmospheric forcing in the Los Angeles Basin was investigated by means of a numerical model and observations. Special attention was paid to airflows that are important to the transport of pollutants in the region. The numerical model was modified in order to improve its numerical stability and enhance its accuracy in the context of sharp topographic relief and strong sea/land thermal contrasts. Output from two simulations were compared with observations to document the model's strengths and weaknesses. Overall, the model results compared well with the observations. Large-scale conditions typical of summer and winter smog episodes were discovered by compositing cases described in the literature. Summer and winter simulations were performed, with and without the large-scale winds typical of the summer and winter episodes, and the results were analyzed. Light geostrophic winds were found to have little influence on the strong mesoscale circulations predicted for the summer day, but stronger geostrophic winds exerted considerable influence on the weaker mesoscale circulations that occurred on the winter day.

  19. 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

  20. A new model to simulate the Martian mesoscale and microscale atmospheric circulation: Validation and first results

    NASA Astrophysics Data System (ADS)

    Spiga, Aymeric; Forget, François

    2009-02-01

    The Laboratoire de Météorologie Dynamique (LMD) Mesoscale Model is a new versatile simulator of the Martian atmosphere and environment at horizontal scales ranging from hundreds of kilometers to tens of meters. The model combines the National Centers for Environmental Prediction(NCEP)-National Center for Atmospheric Research (NCAR) fully compressible nonhydrostatic Advanced Research Weather Research and Forecasting (ARW-WRF) dynamical core, adapted to Mars, with the LMD-general circulation model (GCM) comprehensive set of physical parameterizations for the Martian dust, CO2, water, and photochemistry cycles. Since LMD-GCM large-scale simulations are also used to drive the mesoscale model at the boundaries of the chosen domain of interest, a high level of downscaling consistency is reached. To define the initial state and the atmosphere at the domain boundaries, a specific ``hybrid'' vertical interpolation from the coarse-resolution GCM fields to the high-resolution mesoscale domain is used to ensure the stability and the physical relevancy of the simulations. Used in synoptic-scale mode with a cyclic domain wrapped around the planet, the mesoscale model correctly replicates the main large-scale thermal structure and the zonally propagating waves. The model diagnostics of the near-surface pressure, wind, and temperature daily cycles in Chryse Planitia are in accordance with the Viking and Pathfinder measurements. Afternoon gustiness at the respective landing sites is adequately accounted for on the condition that convective adjustment is turned off in the mesoscale simulations. On the rims of Valles Marineris, intense daytime anabatic (~30 m s-1) and nighttime katabatic (~40 m s-1) winds are predicted. Within the canyon corridors, topographical channeling can amplify the wind a few kilometers above the ground, especially during the night. Through large-eddy simulations in Gusev Crater, the model describes the mixing layer growth during the afternoon, and the

  1. Turbulence Parameterizations for Convective Boundary Layers in High-Resolution Mesoscale Models

    DTIC Science & Technology

    2003-12-01

    radars are especially dependent on clear weather conditions for effective operations. For example, dust storms and low cloud cover were weather events...PAGES 160 14. SUBJECT TERMS Grid Resolution, Parameterizations, Boundary Layer, Mesoscale Modeling, COAMPS . 16. PRICE CODE 17. SECURITY...Parameterizations in COAMPS using aircraft measurements. This work was also supported in part by a grant of computer time from the DOD high

  2. Coastal Foredune Evolution, Part 2: Modeling Approaches for Meso-Scale Morphologic Evolution

    DTIC Science & Technology

    2017-03-01

    ERDC/CHL CHETN-II-57 March 2017 Approved for public release; distribution is unlimited. Coastal Foredune Evolution , Part 2: Modeling Approaches...for Meso-Scale Morphologic Evolution by Margaret L. Palmsten1, Katherine L. Brodie2, and Nicholas J. Spore2 PURPOSE: This Coastal and Hydraulics...Engineering Technical Note (CHETN) is the second of two CHETNs focused on improving technologies to forecast coastal foredune evolution . Part 1

  3. An evaluation of randomization models for nested species subsets analysis.

    PubMed

    Cook, Rosamonde R; Quinn, James F

    1998-02-01

    Randomization models, often termed "null" models, have been widely used since the 1970s in studies of species community and biogeographic patterns. More recently they have been used to test for nested species subset patterns (or nestedness) among assemblages of species occupying spatially subdivided habitats, such as island archipelagoes and terrestrial habitat patches. Nestedness occurs when the species occupying small or species-poor sites have a strong tendency to form proper subsets of richer species assemblages. In this paper, we examine the ability of several published simulation models to detect, in an unbiased way, nested subset patterns from a simple matrix of site-by-species presence-absence data. Each approach attempts to build in biological realism by following the assumption that the ecological processes that generated the patterns observed in nature would, if they could be repeated many times over using the same species and landscape configuration, produce islands with the same number of species and species present on the same number of islands as observed. In mathematical terms, the mean marginal totals (column and row sums) of many simulated matrices would match those of the observed matrix. Results of model simulations suggest that the true probability of a species occupying any given site cannot be estimated unambiguously. Nearly all of the models tested were shown to bias simulation matrices toward low levels of nestedness, increasing the probability of a Type I statistical error. Further, desired marginal totals could be obtained only through ad-hoc manipulation of the calculated probabilities. Paradoxically, when such results are achieved, the model is shown to have little statistical power to detect nestedness. This is because nestedness is determined largely by the marginal totals of the matrix themselves, as suggested earlier by Wright and Reeves. We conclude that at the present time, the best null model for nested subset patterns may be one

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

    NASA Astrophysics Data System (ADS)

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

    2014-04-01

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

  6. Large-eddy simulation of plume dispersion in the central district of Oklahoma City by coupling a meso-scale meteorological simulation model

    NASA Astrophysics Data System (ADS)

    Nakayama, H.

    2016-12-01

    The model validation of an large-eddy simulation (LES)-based computational fluid dynamics (CFD) model coupled to a numerical weather prediction (NWP) is carried out. The Joint Urban 2003 field experimental data of tracer gas concentration released as puff and 30-minute continuous releases for the case of IOP6 are used to evaluate the performance of the coupling approach. The model used for a mesoscale meteorological simulation is the Weather Research and Forecasting (WRF) model, the Advanced Research WRF Version 3.3.1 (Skamarock et al. 2008). We use a nesting capability to resolve the Oklahoma City region by setting two-way nested, three computational domains. The CFD model used here is based on an LES (Nakayama et al., 2015). The LES model is configured using two domains with one-way between parent and nested domains. The parent and nested domains are set to generate urban boundary layer flows and conduct detailed simulations of plume dispersion within the urban central district, respectively. In the LES model, wind velocity and potential temperature data obtained by the WRF model are imposed at lateral boundaries, and time-dependent turbulent inflow conditions are prescribed using the recycling inflow technique proposed by Kataoka and Mizuno (2002). The surface heat fluxes are calculated using the surface potential temperature obtained by the WRF model.The LES results show that vertical profiles of wind speed, wind direction, and potential temperature are similar to those of the WRF. This indicates that the target meteorological conditions are successfully reproduced in the LES model. The time-averaged concentrations of the LES are considerably different from those of the field experimental data at the several points especially for the puff case. However, the LES generally show reasonable performance in comparison to the experimental data through the continuous and puff release cases. It is concluded that our approach is physically reasonable.

  7. Initialization of mesoscale models - The possible impact of remotely sensed data

    NASA Technical Reports Server (NTRS)

    Gal-Chen, T.

    1983-01-01

    Little or no improvement appears to have been achieved in mesoscale numerical prediction. This has been blamed on inherent unpredictability, insufficient spatial resolution, inadequate parameterization of important physical processes, and errors in the numerical discretization of the governing hydrodynamic equations. Attention is presently given to the more fundamental difficulty of forecasting when present conditions are not known with sufficient accuracy, and to the matching of remotely sensed sounding-capability satellite and all-weather Doppler radar data with mesoscale numerical models. This matching is not straightforward; simple and variational forms of four-dimensional assimilation, and Kalman filtering, are suggested approaches but their practical testing remains to be accomplished. The most severe problem faced is that of the temperature and humidity profiles' vertical resolution.

  8. 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

  9. Representing Hurricanes with a Nested Global Forecast Model

    NASA Astrophysics Data System (ADS)

    Otte, M. J.; Walko, R. L.; Avissar, R.

    2007-12-01

    A global forecast model is essential for predicting hurricane tracks beyond a period of ~2 days since global processes that may influence the longer-term storm tracks can be represented explicitly and there are no errors from the lateral boundary conditions that can propagate into the model domain and diminish the accuracy of the track forecasts. However, global models usually do not have enough horizontal and vertical resolution to produce meaningful hurricane intensity forecasts. Most current operational global forecast models represent the atmosphere horizontally using spherical harmonic basis functions with an equivalent resolution of ~40-50 km. The NOAA Science Advisory Board Hurricane Intensity Research Working Group recommends approximately 1-km-resolution hurricane forecasts in order to represent the important physical processes in the core region of hurricanes that are important to accurately predict hurricane intensity. Even with state-of-the-art computers, it will be many years before global forecasts with 1-km horizontal resolution are practical. To predict both hurricane tracks and intensity well, a nested global model is necessary. Large-scale processes are represented on a coarser, computationally-efficient grid while features such as hurricanes are represented on a high-resolution nest. The global model used in this study is the Ocean-Land-Atmosphere Model (OLAM) being developed at Duke University. OLAM is the global successor to the Regional Atmospheric Modeling System (RAMS), which originated at Colorado State University in 1986. OLAM uses the same physics parameterizations as RAMS, but it solves the governing equations by discretizing the atmosphere on an unstructured triangular finite-volume grid. The triangular grid uses the Arakawa-C staggering and is fully mass conservative. Since the triangular mesh is unstructured, the mesh can be refined to produce much higher horizontal resolution in areas of interest such as near hurricanes. Here, we

  10. The Adriatic Sea modelling system: a nested approach

    NASA Astrophysics Data System (ADS)

    Zavatarelli, M.; Pinardi, N.

    2003-01-01

    A modelling system for the Adriatic Sea has been built within the framework of the Mediterranean Forecasting System Pilot Project. The modelling system consists of a hierarchy of three numerical models (whole Mediterranean Sea, whole Adriatic Sea, Northern Adriatic Basin) coupled among each other by simple one-way, off-line nesting techniques, to downscale the larger scale flow field to highly resolved coastal scale fields. Numerical simulations have been carried out under climatological surface forcing. Simulations were aimed to assess the effectiveness of the nesting techniques and the skill of the system to reproduce known features of the Adriatic Sea circulation phenomenology (main circulation features, dense water formation,flow at the Otranto Strait and coastal circulation characteristics over the northern Adriatic shelf), in view of the pre-operational use of the modelling system. This paper describes the modelling system setup, and discusses the simulation results for the whole Adriatic Sea and its northern basin, comparing the simulations with the observed climatological circulation characteristics. Results obtained with the northern Adriatic model are also compared with the corresponding simulations obtained with the coarser resolution Adriatic model.

  11. 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.

  12. Mesoscale energy deposition footprint model for kiloelectronvolt cluster bombardment of solids.

    PubMed

    Russo, Michael F; Garrison, Barbara J

    2006-10-15

    Molecular dynamics simulations have been performed to model 5-keV C60 and Au3 projectile bombardment of an amorphous water substrate. The goal is to obtain detailed insights into the dynamics of motion in order to develop a straightforward and less computationally demanding model of the process of ejection. The molecular dynamics results provide the basis for the mesoscale energy deposition footprint model. This model provides a method for predicting relative yields based on information from less than 1 ps of simulation time.

  13. 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.

  14. 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.

  15. Toward a Mesoscale Model for the Dynamics of Polymer Solutions

    SciTech Connect

    Miller, G H; Trebotich, D

    2006-10-02

    To model entire microfluidic systems containing solvated polymers we argue that it is necessary to have a numerical stability constraint governed only by the advective CFL condition. Advancements in the treatment of Kramers bead-rod polymer models are presented to enable tightly-coupled fluid-particle algorithms in the context of system-level modeling.

  16. 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.

  17. 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

  18. 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.

  19. 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.

  20. 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…

  1. 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…

  2. The use of satellite estimates of rainfall in the initialization of a mesoscale hurricane model

    NASA Technical Reports Server (NTRS)

    Fiorino, M.

    1979-01-01

    The use of rainfall rate data obtained from satellites to improve the initial specification of the hurricane circulation is discussed with particular reference to the techniques for incorporating rainfall data into high-resolution hurricane models. The variation of latent heating in a numerical model of a steady state tropical cyclone is considered to ascertain what features of the storm motion can be deduced from a given field of latent heat release. A real-data example involving a mesoscale model for hurricane Eloise (1975) has demonstrated that satellite measurements of rainfall may be beneficial to numerical hurricane prediction.

  3. Parameterization of Cumulus Convective Cloud Systems in Mesoscale Forecast Models

    DTIC Science & Technology

    2012-09-30

    and the 6th moments. The development and testing of the parameterization was made using the CIMMS LES explicit warm rain microphysical model. The...implemented into the 3D dynamical framework of the CIMMS LES model where the errors of the parameterization were assessed in a realistic setting. The

  4. 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.

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

    NASA Astrophysics Data System (ADS)

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

    2014-12-01

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

  6. 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.

  7. Mesoscale Modeling of Dynamic Compression of Boron Carbide Polycrystals

    DTIC Science & Technology

    2013-05-01

    which could be modeled using cohesive zone (Clayton, 2005; Clayton et al., 2012a) or continuum damage mechanics (Clayton, 2006; Aslan et al., 2011...Wang et al., 1995; Morris and Krenn, 2000). References Aslan , O., Codero, N., Gaubert, A., Forest, S., 2011. Micromorphic approach to single crystal

  8. Dynamic mesoscale model of dipolar fluids via fluctuating hydrodynamics.

    PubMed

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

    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.

  9. 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

  10. 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.

  11. 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

  12. Dynamic mesoscale model of dipolar fluids via fluctuating hydrodynamics

    NASA Astrophysics Data System (ADS)

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

    2014-11-01

    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.

  13. 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.

  14. Next-Generation Global and Mesoscale Atmospheric Models

    DTIC Science & Technology

    2013-09-30

    explore: 1. Unified high-order continuous Galerkin (CG) and discontinuous Galerkin (DG) spatial discretization methods; 2. Unified high-order... Galerkin (EBG) methods such as the spectral element (SE/CG) and discontinuous Galerkin (DG) methods. However, we have only partly showed the benefits...results of, to our knowledge, the first simulation with moisture for a discontinuous Galerkin (DG) model. The significance of this simulation is that it

  15. 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.

  16. 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.

  17. Asian dust transport during the springtime of year 2001 and 2002 with a nested version of dust transport model

    NASA Astrophysics Data System (ADS)

    Uno, I.; Satake, S.; Hara, Y.; Takemura, T.; Wang, Z.; Carmichael, G. R.

    2002-12-01

    Number of yellow sand (Kosa) observation has been surprisingly increasing in Japan and Korea since 2000. Especially extremely high PM10 concentration (exceeding 0.5mg/m3) was observed in Japan several times in 2002, so we have an urgent scientific and political need to forecast/reproduce the detailed dust emission, transport and deposition processes. Intensive modeling studies have already been conducted to examine transport of Sahara dust and its impact on global radiation budget. One of the important differences between the Sahara desert and the Asian desert (mainly Gobi Desert and Takla Makan Desert) is the elevation of the dust source. The averaged elevation of Gobi Desert is approximately 1500 to 2500 m. These deserts are surrounded by high mountains. Furthermore advance of the recent manmade desertification made complicated land use patches for the arid region in Inner Mongolia. Therefore the development of a high horizontal resolution dust model is highly required. In this study, we will report a newly developed nested version of the dust transport model (as a part of Chemical weather FORecasting System; CFORS) in order to have a better understanding of Asian springtime heady dust episode. Here, CFORS is a multi-tracer, on-line, system built within the RAMS mesoscale meteorological model. A unique feature of nested CFORS is that multiple tracers are run on-line in RAMS under the two-way nesting, so that all the fine-scale on-line meteorological information such as 3-D winds, boundary-layer turbulence, surface fluxes and precipitation amount are directly used by the dust emission and transport at every time step. As a result, nested-CFORS produces with high time resolution 3-dimensional fields of dust distributions and major meteorological parameters under the nesting capability of RAMS. In this work, the dust transport model simulation with the nested-CFORS was conducted between March and April of the years 2001 and 2002, respectively. The sensititivy

  18. Nested Sphere Model for SQUID-based Impedance Magnetocardiography

    NASA Astrophysics Data System (ADS)

    Vajrala, Vijayanand; Nawarathna, Dharmakeerthi; Claycomb, James; Miller, John

    2004-03-01

    An axisymmetric FEM model is used to predict the SQUID response to changes in tissue conductivity and blood volume during the cardiac cycle. The heart is modeled as a nested sphere inside a cylindrical conducting thorax. The current density and resulting magnetic field is calculated during end systolic, end diastolic and diastolic phases. Modeling results are compared to Impedance Magnetocardiography (IMCG) measurements made using a High-Tc SQUID magnetometer in an unshielded environment .In this measurements, a low amplitude ac current is passed through the body through outer electrodes. Variations in blood flow during the cardiac cycle perturb currents that give rise to time varying magnetic fields amplitudes. Applications to inductive IMCG will be discussed.

  19. Mutable polyelectrolyte tube arrays: mesoscale modeling and lateral force microscopy.

    PubMed

    Cranford, Steven W; Han, Lin; Ortiz, Christine; Buehler, Markus J

    2017-08-23

    In this study, the pH-dependent friction of layer-by-layer assemblies of poly(allylamine hydrochloride) and poly(acrylic acid) (PAH/PAA) are quantified for microtube array structures via experimental and simulated lateral force microscopy (LFM). A novel coarse-grain tube model is developed, utilizing a molecular dynamics (MD) framework with a Hertzian soft contact potential (such that F ∼ δ(3/2)) to allow the efficient dynamic simulation of 3D arrays consisting of hundreds of tubes at micrometer length scales. By quantitatively comparing experimental LFM and computational results, the coupling between geometry (tube spacing and swelling) and material properties (intrinsic stiffness) results in a transition from bending dominated deformation to bending combined with inter-tube contact, independent of material adhesion assumptions. Variation of tube spacing (and thus control of contact) can be used to exploit the normal and lateral resistance of the tube arrays as a function of pH (2.0/5.5), beyond the effect of areal tube density, with increased resistances (potential mutability) up to a factor of ∼60. This study provides a novel modeling platform to assess and design dynamic polyelectrolyte-based substrates/coatings with tailorable stimulus-responsive surface friction. Our results show that micro-geometry can be used alongside stimulus-responsive material changes to amplify and systematically tune mutability.

  20. 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.

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

    SciTech Connect

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

    2010-09-01

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

  2. Tight-binding model for materials at mesoscale

    SciTech Connect

    Tai, Yuan-Yen; Choi, Hongchul; Zhu, Wei; Zhu, Jian-Xin

    2016-12-21

    TBM3 is an open source package for computational simulations of quantum materials at multiple scales in length and time. The project originated to investigate the multiferroic behavior in transition-metal oxide heterostructures. The framework has also been designed to study emergent phemona in other quantum materials like 2-dimensional transition-metal dichalcogenides, graphene, topological insulators, and skyrmion in materials, etc. In the long term, we will enable the package for transport and time-resolved phenomena. TBM3 is currently a C++ based numerical tool package and framework for the design and construction of any kind of lattice structures with multi-orbital and spin degrees of freedom. The fortran based portion of the package will be added in the near future. The design of TBM3 is in a highly flexible and reusable framework and the tight-binding parameters can be modeled or informed by DFT calculations. It is currently GPU enabled and feature of CPU enabled MPI will be added in the future.

  3. Mesoscale Ocean Large Eddy Simulations Using High-resolution Ocean Models

    NASA Astrophysics Data System (ADS)

    Pearson, B.; Fox-Kemper, B.; Bachman, S.; Bryan, F.; Bailey, D. A.

    2016-02-01

    Inaccurate parameterization of sub-grid eddies can cause excessive damping and spurious diapycnal mixing, especially in high-resolution [O(10km)] ocean models. The Mesoscale Ocean Large Eddy Simulation (MOLES) approach provides a framework for developing resolution- and flow-adaptive parameterizations of eddy effects. Large eddy simulation techniques are commonly used to simulate 3D turbulence, and MOLES is modified to be appropriate for the more two-dimensional nature of mesoscale ocean turbulence. However, the effect of MOLES in high-resolution ocean models has not been investigated extensively. We will contrast results, and cost, from a suite of idealized simulations of frontal spin-down (MITgcm) and from high-resolution global climate models (0.1o, POP2), under a variety of eddy parameterizations. These include MOLES based upon 2D turbulence theory, MOLES based upon quasi-geostrophic (QG) turbulence theory, and traditional biharmonic schemes. The idealized simulations show that MOLES (particularly QG) improves the spectral slopes of energy and enstrophy near the grid-scale when compared to more traditional eddy parameterizations, across a range of grid resolutions. In the high-resolution global climate model we compare the effect of different parameterizations on the spectral characteristics of the simulated flow, and on the large-scale transport. Using MOLES in a climate model results in greater energy and variability near the grid scale, and this produces a flow, which, spectrally, is more consistent with an inertial turbulent cascade and observations of eddy behavior.

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

    NASA Astrophysics Data System (ADS)

    Mancini, Derrick; Deshmukh, Sanket; Sankaranarayanan, Subramanian

    2015-03-01

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

  5. Mesoscale/convective interaction

    NASA Technical Reports Server (NTRS)

    Haines, P. A.; Sun, W. Y.

    1988-01-01

    A novel cumulus parameterization scheme (CPS) has been developed in order to account for mesoscale/convective-scale interaction which considers both the mesoscale and convective scale mass and moisture budgets, under the assumption that the heating rate is a maximum for given environmental conditions. The basis of the CPS is a detailed, quasi-one-dimensional cloud model that calculates mass and moisture fluxes similar to those calculated by the Schlesinger (1978) three-dimensional model.

  6. Nested Grid Modeling of Circulation on the Inner-shelf

    NASA Astrophysics Data System (ADS)

    Cai, D.; Haas, K. A.; Di Lorenzo, E.; Suanda, S. H.; Kumar, N.; Miller, A. J.; Feddersen, F.; Edwards, C. A.

    2016-02-01

    The dynamical controls on the circulation for the inner shelf (5-30 m water depth) are complex due to dominant balances associated with the many temporal and spatial scales of surface and wave forcing along with intrinsic variability (instabilities, internal wave propagation, etc.). To shed some light on this problem, numerical simulations of the inner shelf region that roughly corresponds to the Point Sal beach off the coast of Point Conception are conducted by coupling ROMS and SWAN modules of the COAWST model system. The model system is configured with four nested grids with resolutions ranging from approximately 600 m to the outer shelf ( 200 m) to the inner shelf ( 66 m) and finally to the surf zone ( 22 m). A solution from a 1 km grid encompassing our domain provides the boundary conditions for the 600 m grid. Barotropic tidal forcing is incorporated at the 600 m grid to provide tidal variability. Surface gravity waves are introduced beginning at the 200 m nested grid in order to resolve the influence of wave driven currents originating in the surf zone on the process inner shelf. The simulations focus on the time period of June - July, 2015 corresponding to an ONR pilot study in which observational experiment data was collected. The experiment data in part consists of in situ measurement, which includes mooring with conductivity, temperature, depth, and flow velocity. In addition, multiple modalities of remote sensing data was collected including land-based and aerial radar and video, which can provide information on sea surface fronts, height, and temperature and multispectral images of the biological condition. This data will be used to test the capability of our model to exhibit realistic behavior in terms of flow structures on the shelf, alongshore flows, and internal tides.

  7. 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.

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

    NASA Astrophysics Data System (ADS)

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

    2013-01-01

    Abstract-Generation and propagation of shock waves by meteorite impact is significantly affected by material properties such as porosity, water content, and strength. The objective of this work was to quantify processes related to the shock-induced compaction of pore space by numerical <span class="hlt">modeling</span>, and compare the results with data obtained in the framework of the Multidisciplinary Experimental and <span class="hlt">Modeling</span> Impact Research Network (MEMIN) impact experiments. We use <span class="hlt">mesoscale</span> <span class="hlt">models</span> resolving the collapse of individual pores to validate macroscopic (homogenized) approaches describing the bulk behavior of porous and water-saturated materials in large-scale <span class="hlt">models</span> of crater formation, and to quantify localized shock amplification as a result of pore space crushing. We carried out a suite of numerical <span class="hlt">models</span> of planar shock wave propagation through a well-defined area (the "sample") of porous and/or water-saturated material. The porous sample is either represented by a homogeneous unit where porosity is treated as a state variable (macroscale <span class="hlt">model</span>) and water content by an equation of state for mixed material (ANEOS) or by a defined number of individually resolved pores (<span class="hlt">mesoscale</span> <span class="hlt">model</span>). We varied porosity and water content and measured thermodynamic parameters such as shock wave velocity and particle velocity on meso- and macroscales in separate simulations. The <span class="hlt">mesoscale</span> <span class="hlt">models</span> provide additional data on the heterogeneous distribution of peak shock pressures as a consequence of the complex superposition of reflecting rarefaction waves and shock waves originating from the crushing of pores. We quantify the bulk effect of porosity, the reduction in shock pressure, in terms of Hugoniot data as a function of porosity, water content, and strength of a quartzite matrix. We find a good agreement between meso-, macroscale <span class="hlt">models</span> and Hugoniot data from shock experiments. We also propose a combination of a porosity compaction <span class="hlt">model</span> (ɛ-α <span class="hlt">model</span>) that was</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015EGUGA..17.1154P','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015EGUGA..17.1154P"><span>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/2003EAEJA.....4042Z','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2003EAEJA.....4042Z"><span>Generation of <span class="hlt">mesoscale</span> eddies and squirts in the southeast Baltic Sea: <span class="hlt">modelling</span> and observations</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Zhurbas, V.; Stipa, T.; Mälkki, P.; Paka, V.; Golenko, N.; Hense, I.</p> <p>2003-04-01</p> <p>Closely spaced CTD measurements performed in the southeast Baltic Sea during summertime reveal localized simultaneous deepenings of the seasonal thermocline and swellings of the permanent halocline which result in localized convergences of isopycnals towards the intermediate layer. In view of geostrophic balance, such <span class="hlt">mesoscale</span> baroclinic disturbances can be interpreted as the cyclonic eddies within the intermediate layer. They were observed in the Bornholm Deep, the Stolpe Channel ,the Gulf of Gdansk, and the southern part of East Gotland Basin. In the case of the Stolpe Channel, the cyclones were satisfactory reproduced in numerical experiments with a sigma-coordinate, Princeton Ocean <span class="hlt">Model</span> (POM) in which horizontal grid sell size was as small as 0.5 km. The diameter of <span class="hlt">modelled</span> cyclones (approx. 15 km) fits well that of the observations. The cyclones are shown to be generated during the adjustment of the high potential vorticity (PV) outflow (in this particular case from the Bornholm basin via the Stolpe Sill) to low vorticity environment by vortex stretching (so-called the PV outflow hypothesis by Spall and Price (1998)). In addition to the cyclones in the Stolpe Channel, numerical experiments with easterly wind yield exiting possibility to watch squirts and <span class="hlt">mesoscale</span> eddies, both cyclones and anticyclones, generated in the upper layer due to the instability of the upwelling front off the southern coast of the sea.</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>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/2005PhDT........30V','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2005PhDT........30V"><span>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/2010ems..confE.180D','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2010ems..confE.180D"><span>Numerical Weather Prediction Over Caucasus Region With <span class="hlt">Nested</span> Grid <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>Davitashvili, Dr.; Kutaladze, Dr.; Kvatadze, Dr.</p> <p>2010-09-01</p> <p>Global atmosphere <span class="hlt">models</span>, which describe the weather processes, give the general character of the weather but can't catch the smaller scale processes, especially local weather for the territories with compound topography. Small-scale processes such as convection often dominate the local weather, which cannot be explicitly represented in <span class="hlt">models</span> with grid size more then 10 km. A much finer grid is required to properly simulate frontal structures and represent cumulus convection. Georgia lies to the south of the Major Caucasian Ridge and the Lesser Caucasus mountains occupy the southern part of Georgia. About 85 percent of the total land area occupies complex mountain ranges.Therefore for the territory of Georgia it is necessary to use atmosphere <span class="hlt">models</span> with a very high resolution <span class="hlt">nested</span> grid system taking into account main orographic features of the area. We have elaborated and configured Whether Research Forecast - Advanced Researcher Weather (WRF-ARW) <span class="hlt">model</span> for Caucasus region considering geographical-landscape character, topography height, land use, soil type and temperature in deep layers, vegetation monthly distribution, albedo and others. Porting of WRF-ARW application to the grid was a good opportunity for running <span class="hlt">model</span> on larger number of CPUs and storing large amount of data on the grid storage elements. On the grid WRF was compiled for both Open MP and MPI (Shared + Distributed memory) environment and WPS was compiled for serial environment using PGI (v7.1.6, MPI- version 1.2.7) on the platform Linux-x86. In searching of optimal execution time for time saving different <span class="hlt">model</span> directory structures and storage schema was used. Simulations were performed using a set of 2 domains with horizontal grid-point resolutions of 15 and 5 km, both defined as those currently being used for operational forecasts The coarser domain is a grid of 94x102 points which covers the South Caucasus region, while the <span class="hlt">nested</span> inner domain has a grid size of 70x70 points mainly</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.dtic.mil/docs/citations/ADA631417','DTIC-ST'); return false;" href="http://www.dtic.mil/docs/citations/ADA631417"><span><span class="hlt">Mesoscale</span> Ionospheric Prediction</span></a></p> <p><a target="_blank" href="http://www.dtic.mil/">DTIC Science & Technology</a></p> <p></p> <p>2016-06-13</p> <p><span class="hlt">Mesoscale</span> Ionospheric Prediction Gary S. Bust 10000 Burnet Austin Texas, 78758 phone: (512) 835-3623 fax: (512) 835-3808 email: gbust...data assimilation analysis, and the coupling between the <span class="hlt">model</span> and analysis, is a <span class="hlt">Mesoscale</span> Assimilative Prediction System (MAPS) that can be used...subject to a penalty for failing to comply with a collection of information if it does not display a currently valid OMB control number. 1. REPORT DATE 30</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=20020002371&hterms=Tom&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D60%26Ntt%3DTom','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=20020002371&hterms=Tom&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D60%26Ntt%3DTom"><span>Evidence of Stratosphere-to-Troposphere Transport Within a <span class="hlt">Mesoscale</span> <span class="hlt">Model</span> and TOMS Total Ozone</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Olsen, Mark A.; Stanford, John L.; Einaudi, Franco (Technical Monitor)</p> <p>2001-01-01</p> <p>We present evidence for stratospheric mass transport into, and remaining in, the troposphere in an intense midlatitude cyclone. <span class="hlt">Mesoscale</span> forecast <span class="hlt">model</span> analysis fields from the <span class="hlt">Mesoscale</span> Analysis and Prediction System (MAPS) were compared with total ozone observations from the Total Ozone Measurement Spectrometer (TOMS). Coupled with parcel back-trajectory calculations, the analyses suggest two mechanisms contributed to the mass exchange: (1) A region of dynamical ly-induced exchange occurred on the cyclone's southern edge. Parcels originally in the stratosphere crossed the jet core and experienced dilution by turbulent mixing with tropospheric air. (2) Diabatic effects reduced parcel potential vorticity (PV) for trajectories traversing precipitation regions, resulting in a "PV-hole" signature in the cyclone center. Air with lower-stratospheric values of ozone and water vapor was left in the troposphere. The strength of the latter process may be atypical. These results, combined with other research, suggest that precipitation-induced diabatic effects can significantly modify, (either decreasing or increasing) parcel potential vorticity, depending on parcel trajectory configuration with respect to jet core and maximum heating regions. In addition, these results underscore the importance of using not only PV but also chemical constituents for diagnoses of stratosphere-troposphere exchange (STE).</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>Controlled meteorological (CMET) balloon profiling of the Arctic atmospheric boundary layer around Spitsbergen compared to a <span class="hlt">mesoscale</span> <span class="hlt">model</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Roberts, T. J.; Dütsch, M.; Hole, L. R.; Voss, P. B.</p> <p>2015-10-01</p> <p>Observations from CMET (Controlled Meteorological) balloons are analyzed in combination with <span class="hlt">mesoscale</span> <span class="hlt">model</span> simulations to provide insights into tropospheric meteorological conditions (temperature, humidity, wind-speed) around Svalbard, European High Arctic. Five Controlled Meteorological (CMET) balloons were launched from Ny-Ålesund in Svalbard over 5-12 May 2011, and measured vertical atmospheric profiles above Spitsbergen Island and over coastal areas to both the east and west. One notable CMET flight achieved a suite of 18 continuous soundings that probed the Arctic marine boundary layer over a period of more than 10 h. The CMET profiles are compared to simulations using the Weather Research and Forecasting (WRF) <span class="hlt">model</span> using <span class="hlt">nested</span> grids and three different boundary layer schemes. Variability between the three <span class="hlt">model</span> schemes was typically smaller than the discrepancies between the <span class="hlt">model</span> runs and the observations. Over Spitsbergen, the CMET flights identified temperature inversions and low-level jets (LLJ) that were not captured by the <span class="hlt">model</span>. Nevertheless, the <span class="hlt">model</span> largely reproduced time-series obtained from the Ny-Ålesund meteorological station, with exception of surface winds during the LLJ. Over sea-ice east of Svalbard the <span class="hlt">model</span> underestimated potential temperature and overestimated wind-speed compared to the CMET observations. This is most likely due to the full sea-ice coverage assumed by the <span class="hlt">model</span>, and consequent underestimation of ocean-atmosphere exchange in the presence of leads or fractional coverage. The suite of continuous CMET soundings over a sea-ice free region to the northwest of Svalbard are analysed spatially and temporally, and compared to the <span class="hlt">model</span>. The observed along-flight daytime increase in relative humidity is interpreted in terms of the diurnal cycle, and in the context of marine and terrestrial air-mass influences. Analysis of the balloon trajectory during the CMET soundings identifies strong wind-shear, with a low-level channeled</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014AGUFM.A43A3240T','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014AGUFM.A43A3240T"><span>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/28406896','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/28406896"><span>Inferring modulators of genetic interactions with epistatic <span class="hlt">nested</span> effects <span class="hlt">models</span>.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Pirkl, Martin; Diekmann, Madeline; van der Wees, Marlies; Beerenwinkel, Niko; Fröhlich, Holger; Markowetz, Florian</p> <p>2017-04-01</p> <p>Maps of genetic interactions can dissect functional redundancies in cellular networks. Gene expression profiles as high-dimensional molecular readouts of combinatorial perturbations provide a detailed view of genetic interactions, but can be hard to interpret if different gene sets respond in different ways (called mixed epistasis). Here we test the hypothesis that mixed epistasis between a gene pair can be explained by the action of a third gene that modulates the interaction. We have extended the framework of <span class="hlt">Nested</span> Effects <span class="hlt">Models</span> (NEMs), a type of graphical <span class="hlt">model</span> specifically tailored to analyze high-dimensional gene perturbation data, to incorporate logical functions that describe interactions between regulators on downstream genes and proteins. We benchmark our approach in the controlled setting of a simulation study and show high accuracy in inferring the correct <span class="hlt">model</span>. In an application to data from deletion mutants of kinases and phosphatases in S. cerevisiae we show that epistatic NEMs can point to modulators of genetic interactions. Our approach is implemented in the R-package 'epiNEM' available from https://github.com/cbg-ethz/epiNEM and https://bioconductor.org/packages/epiNEM/.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/1988PhDT.........5U','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/1988PhDT.........5U"><span><span class="hlt">Mesoscale</span> Circulations in the LOS Angeles Basin: a Numerical <span class="hlt">Modeling</span> Study</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Ulrickson, Brian Lee</p> <p>1988-08-01</p> <p><span class="hlt">Mesoscale</span> atmospheric forcing in the Los Angeles Basin was investigated by means of a numerical <span class="hlt">model</span> and observations. Special attention was paid to airflows that are important to the transport of pollutants in the region. The numerical <span class="hlt">model</span> was modified in order to improve its numerical stability and enhance its accuracy in the context of sharp topographic relief and strong sea/land thermal contrasts. Output from two simulations were compared with observations to document the <span class="hlt">model</span>'s strengths and weaknesses. Overall, the <span class="hlt">model</span> results compared well with the observations. Large-scale conditions typical of summer and winter smog episodes were discovered by compositing cases described in the literature. Summer and winter simulations were performed, with and without the large-scale winds typical of the summer and winter episodes, and the results were analyzed. Light geostrophic winds were found to have little influence on the strong <span class="hlt">mesoscale</span> circulations predicted for the summer day, but stronger geostrophic winds exerted considerable influence on the weaker <span class="hlt">mesoscale</span> circulations that occurred on the winter day. Standard <span class="hlt">model</span> predictions and computations of air-parcel trajectories indicate that daytime upslope flows near the mountains are a significant factor in the ventilation of the basin, inducing basin -wide airflow that modifies the sea breeze circulation, whose influence is limited to the coastal parts of the basin. Heating of the mountain slopes also induces a weak onshore flow in the inversion layer and above. Air that is transported from the basin's shallow boundary layer to the ridgetops is predicted to rise in updrafts there and be convectively mixed to great heights, where it is then transported horizontally by winds aloft. Boundary layer air is also predicted to leave the basin through three mountains passes, be convectively mixed through a much deeper boundary layer in the desert, and travel back into the basin above the inversion base. Air that is</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>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> </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('https://ntrs.nasa.gov/search.jsp?R=20030054450&hterms=sea+breeze&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D30%26Ntt%3Dsea%2Bbreeze','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=20030054450&hterms=sea+breeze&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D30%26Ntt%3Dsea%2Bbreeze"><span>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/2009ems..confE.264R','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2009ems..confE.264R"><span>Coupling of the atmospheric <span class="hlt">mesoscale</span> <span class="hlt">model</span> FOOT3DK to a photosynthesis <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, M.; Zacharias, S.; Kerschgens, M.</p> <p>2009-09-01</p> <p>The interdisciplinary project SFB Transregio 32 aims at monitoring and <span class="hlt">modelling</span> of patterns in soil-vegetation-atmosphere systems. Field and aircraft measurements show temporal and spatial small scale variability of CO2 and H2O fluxes, which are associated with small scale vegetation structures of varying photosynthetic activity. Within the subproject D1 of the SFB Transregio 32 the influence of surface heterogenities on atmospheric fluxes is simulated using the atmospheric <span class="hlt">mesoscale</span> <span class="hlt">model</span> FOOT3DK. Simulations are performed for the TR32 investigation area near Selhausen, located in North-Rhine-Westphalia, Germany, with a horizontal resolution up to 100 m. Since in the original <span class="hlt">model</span> set-up no carbon cycle is included, FOOT3DK is coupled to a photosynthesis <span class="hlt">model</span>, which consists of a C3 single-leaf <span class="hlt">model</span> following Farquhar et al. (1980). Big-leaf approaches tend to overestimate photosynthesis activity, therefore an extended big-leaf <span class="hlt">model</span> (de Pury and Farquhar, 1997) is used for the upscaling from leaf to canopy scale. In this so-called sun/shade <span class="hlt">model</span> the canopy is divided into sunlit and shaded fractions and the net CO2 fluxes are calculated for both fractions separately. For the validation simulations with the stand-alone version of the photosynthesis <span class="hlt">model</span> are compared with field measurements for wheat and sugarbeet. Despite some slight overestimations simulated CO2 fluxes exhibit a good overall agreement with measured values. The general diurnal variation as well as local extrema (e.g. caused by clouds) are reproduced well. High resolution simulations of the coupled FOOT3DK-photosynthesis <span class="hlt">model</span> show reasonable results. While the diurnal cycle is matched well, the magnitudes of the simulated CO2 fluxes are considerably overestimated compared to measurements. The overestimations are probably caused by the ratio of photosynthetic active radiation to incoming solar radiation, which currently is assumed to be constant. To investigate the influence of small scale</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>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://hdl.handle.net/2060/20010037609','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20010037609"><span>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('https://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="https://ntrs.nasa.gov/search.jsp?R=19880060530&hterms=pea&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D80%26Ntt%3Dpea"><span><span class="hlt">Mesoscale</span> spiral vortex embedded within a Lake Michigan snow squall band - High resolution satellite observations and numerical <span class="hlt">model</span> simulations</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Lyons, Walter A.; Keen, Cecil S.; Hjelmfelt, Mark; Pease, Steven R.</p> <p>1988-01-01</p> <p>It is known that Great Lakes snow squall convection occurs in a variety of different modes depending on various factors such as air-water temperature contrast, boundary-layer wind shear, and geostrophic wind direction. An exceptional and often neglected source of data for <span class="hlt">mesoscale</span> cloud studies is the ultrahigh resolution multispectral data produced by Landsat satellites. On October 19, 1972, a clearly defined spiral vortex was noted in a Landsat-1 image near the southern end of Lake Michigan during an exceptionally early cold air outbreak over a still very warm lake. In a numerical simulation using a three-dimensional Eulerian hydrostatic primitive equation <span class="hlt">mesoscale</span> <span class="hlt">model</span> with an initially uniform wind field, a definite analog to the observed vortex was generated. This suggests that intense surface heating can be a principal cause in the development of a low-level <span class="hlt">mesoscale</span> vortex.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2007JGRC..112.3S14C','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2007JGRC..112.3S14C"><span>Simulation and characterization of the Adriatic Sea <span class="hlt">mesoscale</span> variability</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Cushman-Roisin, Benoit; Korotenko, Konstantin A.; Galos, Camelia E.; Dietrich, David E.</p> <p>2007-03-01</p> <p>This paper presents simulations of the Adriatic Sea using the DieCAST <span class="hlt">model</span> applied on a 1.2-min grid (about 2-km resolution). The simulations resolve the <span class="hlt">mesoscale</span> variability because the grid size falls below the first baroclinic deformation radius (about 5-10 km) and DieCAST has very low horizontal dissipation. The <span class="hlt">model</span> is initialized with seasonally averaged temperature and salinity data and forced with climatological winds and surface buoyancy fluxes (both heat flux and evaporation minus precipitation). River discharges are varied daily according to a perpetual year for every river, and the open-boundary conditions at Otranto Strait are obtained by <span class="hlt">nesting</span> in two larger-scale <span class="hlt">models</span>. The present simulations demonstrate that the DieCAST <span class="hlt">model</span> allows <span class="hlt">mesoscale</span> instabilities to develop at length scales of 5-20 km and over time scales of a few days. The simulated variability exhibits pronounced similarities with the actual <span class="hlt">mesoscale</span> variability, in terms of location, nature and temporal evolution of the features. Meanders, swirls and eddies are noted along the relatively smooth Italian coast while offshore jets and filaments better describe the <span class="hlt">mesoscale</span> activity along the more rugged coast of Croatia. In sum, DieCAST is highly suitable for the study of <span class="hlt">mesoscale</span> variability in the Adriatic Sea. The present simulations also show that the seasonal hydrography of the Adriatic Sea is intrinsically unstable to <span class="hlt">mesoscale</span> perturbations, and that the <span class="hlt">mesoscale</span> variability along the Italian coast is the result of baroclinic instability of the Western Adriatic Current. It is shown how the properties of this instability are related to the local bottom topography.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2011JChPh.135j4105G','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2011JChPh.135j4105G"><span>Local pressure components and surface tension of spherical interfaces. Thermodynamic versus mechanical definitions. I. A <span class="hlt">mesoscale</span> <span class="hlt">modeling</span> of droplets</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Ghoufi, Aziz; Malfreyt, Patrice</p> <p>2011-09-01</p> <p>We report <span class="hlt">mesoscale</span> simulations of spherical drops to investigate the surface tension and mechanical properties. The Monte Carlo simulations are performed with the multibody potential commonly used in the many-body dissipative particle dynamics simulations. We establish here the calculation of the local normal and transverse components of the pressure tensor via the perturbation volume within the thermodynamic route. The different profiles of these components are compared to those calculated using the mechanical approach. To complete the <span class="hlt">mesoscale</span> <span class="hlt">modeling</span> of drops, we investigate the curvature dependence of the surface tension in order to calculate the Tolman's length, which is found to be negative.</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>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('https://ntrs.nasa.gov/search.jsp?R=20170001444&hterms=oceans&qs=N%3D0%26Ntk%3DAll%26Ntx%3Dmode%2Bmatchall%26Ntt%3Doceans','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=20170001444&hterms=oceans&qs=N%3D0%26Ntk%3DAll%26Ntx%3Dmode%2Bmatchall%26Ntt%3Doceans"><span>The dependence of the oceans MOC on <span class="hlt">mesoscale</span> eddy diffusivities: A <span class="hlt">model</span> study</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Marshall, John; Scott, Jeffery R.; Romanou, Anastasia; Kelley, Maxwell; Leboissetier, Anthony</p> <p>2017-01-01</p> <p>The dependence of the depth and strength of the ocean's global meridional overturning cells (MOC) on the specification of <span class="hlt">mesoscale</span> eddy diffusivity (K) is explored in two ocean <span class="hlt">models</span>. The GISS and MIT ocean <span class="hlt">models</span> are driven by the same prescribed forcing fields, configured in similar ways, spun up to equilibrium for a range of K 's and the resulting MOCs mapped and documented. Scaling laws implicit in modern theories of the MOC are used to rationalize the results. In all calculations the K used in the computation of eddy-induced circulation and that used in the representation of eddy stirring along neutral surfaces, is set to the same value but is changed across experiments. We are able to connect changes in the strength and depth of the Atlantic MOC, the southern ocean upwelling MOC, and the deep cell emanating from Antarctica, to changes in K.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017OcMod.111....1M','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017OcMod.111....1M"><span>The dependence of the ocean's MOC on <span class="hlt">mesoscale</span> eddy diffusivities: A <span class="hlt">model</span> study</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Marshall, John; Scott, Jeffery R.; Romanou, Anastasia; Kelley, Maxwell; Leboissetier, Anthony</p> <p>2017-03-01</p> <p>The dependence of the depth and strength of the ocean's global meridional overturning cells (MOC) on the specification of <span class="hlt">mesoscale</span> eddy diffusivity (K) is explored in two ocean <span class="hlt">models</span>. The GISS and MIT ocean <span class="hlt">models</span> are driven by the same prescribed forcing fields, configured in similar ways, spun up to equilibrium for a range of K's and the resulting MOCs mapped and documented. Scaling laws implicit in modern theories of the MOC are used to rationalize the results. In all calculations the K used in the computation of eddy-induced circulation and that used in the representation of eddy stirring along neutral surfaces, is set to the same value but is changed across experiments. We are able to connect changes in the strength and depth of the Atlantic MOC, the southern ocean upwelling MOC, and the deep cell emanating from Antarctica, to changes in K.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=20170001444&hterms=Ocean&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D10%26Ntt%3DOcean','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=20170001444&hterms=Ocean&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D10%26Ntt%3DOcean"><span>The dependence of the oceans MOC on <span class="hlt">mesoscale</span> eddy diffusivities: A <span class="hlt">model</span> study</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Marshall, John; Scott, Jeffery R.; Romanou, Anastasia; Kelley, Maxwell; Leboissetier, Anthony</p> <p>2017-01-01</p> <p>The dependence of the depth and strength of the ocean's global meridional overturning cells (MOC) on the specification of <span class="hlt">mesoscale</span> eddy diffusivity (K) is explored in two ocean <span class="hlt">models</span>. The GISS and MIT ocean <span class="hlt">models</span> are driven by the same prescribed forcing fields, configured in similar ways, spun up to equilibrium for a range of K 's and the resulting MOCs mapped and documented. Scaling laws implicit in modern theories of the MOC are used to rationalize the results. In all calculations the K used in the computation of eddy-induced circulation and that used in the representation of eddy stirring along neutral surfaces, is set to the same value but is changed across experiments. We are able to connect changes in the strength and depth of the Atlantic MOC, the southern ocean upwelling MOC, and the deep cell emanating from Antarctica, to changes in K.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/scitech/biblio/1222552','SCIGOV-STC'); return false;" href="https://www.osti.gov/scitech/biblio/1222552"><span>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('https://ntrs.nasa.gov/search.jsp?R=19870024426&hterms=static+dynamic&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D80%26Ntt%3Dstatic%2Bdynamic','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=19870024426&hterms=static+dynamic&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D80%26Ntt%3Dstatic%2Bdynamic"><span>Dynamic and static initialization of a <span class="hlt">mesoscale</span> <span class="hlt">model</span> using VAS satellite data</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Beauchamp, J. G.; Warner, T. T.</p> <p>1985-01-01</p> <p>Various <span class="hlt">mesoscale</span> weather forecast <span class="hlt">model</span> initialization procedures were tested in seven simulation forecasts for a 12 hr period in July 1981. Attention was given to the impacts of using as input radiosonde data, VISSR Atmospheric Sounder (VAS) data and a combination of VAS and data from a smoothed global analysis. The data were assimilated with successive correction objective analysis procedures. The <span class="hlt">model</span> had a 60 km horizontal grid-length resolution, 14 layers in the vertical, and accounted for short- and long-wave energy in the surface energy budget but not in the atmosphere. Conventional data were used for the mass and moisture fields. The trials showed that VAS data enhanced the predictions of the temperature and mass variables, while winds were least accurately predicted when VAS data were entered in the initializations. Finally, statically initialized precipitation forecasts from radiosonde and/or VAS data exhibited equal skill.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016IzAOP..52..560D','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016IzAOP..52..560D"><span><span class="hlt">Modeling</span> meso- and sub-<span class="hlt">mesoscale</span> circulation along the eastern Crimean coast using numerical calculations</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Demyshev, S. G.; Evstigneeva, N. A.</p> <p>2016-09-01</p> <p>A numerical experiment has been carried out using a hydrodynamical <span class="hlt">model</span> with nonlinear equations of motion and heat and salt advection to reconstruct the fields of hydrophysical parameters taking into account the real atmospheric forcing for the autumn season along the southern coast of the Crimean Peninsula. The studied part of the coast is situated at 44.25°N 33.95°E/44.72°N 34.55°E. High spatial resolution is used for <span class="hlt">modeling</span>: 350 m in the horizontal plane with 38 layers in the vertical; the bottom topography is described in detail with 500 m resolution. Detected and studied meso- and sub-<span class="hlt">mesoscale</span> structures in the current field agree well with the observational data, which is impossible or hard to identify in numerical experiments with coarser resolution. Their kinematic characteristics and the lifetime are defined and some mechanisms of their origin are suggested.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2000MeApp...7..193A','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2000MeApp...7..193A"><span>The impact of observations on <span class="hlt">Mesoscale</span> <span class="hlt">Model</span> forecasts of three-hourly rainfall accumulations</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Anderson, S. R.; Graham, R. J.; Bader, M. J.</p> <p>2000-09-01</p> <p>The aim of data-impact studies at the UK Met. Office is to investigate how observations affect the accuracy of <span class="hlt">model</span> forecasts. Results from such experiments provide useful evidence on which to base the design of observational networks. This project, using a case study approach, investigated the relative benefit of different observation types within The Met. Office's <span class="hlt">Mesoscale</span> <span class="hlt">Model</span> domain on forecasts of three-hourly precipitation accumulation over the UK up to 12 hours ahead. The method used assesses the impact of assimilating single observation types, or a limited combination of types, where impact is measured against a control forecast obtained after a dummy assimilation using no observations. In experiments for 13 case studies, the observation types that most frequently provided a beneficial impact when presented alone to the assimilation were sonde data, surface data and data from the Moisture Observation Processing System (MOPS).</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>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/2010AGUFM.A33B0157L','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2010AGUFM.A33B0157L"><span>Impact of data assimilation on Chukchi/Beaufort Seas <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>Liu, F.; Krieger, J.; Zhang, J.</p> <p>2010-12-01</p> <p>Offshore development in the Chukchi/Beaufort Seas requires an improved understanding of the surface wind field, a crucial parameter for assessing and predicting dispersal and movement of oil spills. A study has thus been established to investigate the <span class="hlt">mesoscale</span> features of the surface wind field throughout this region. In this study, we focus on investigating the impact of data assimilation on the simulation of the Chukchi/Beaufort Seas <span class="hlt">mesoscale</span> surface wind field with the Weather Research and Forecasting <span class="hlt">model</span> (WRF) and its variational data assimilation system (WRF-Var). In the application of WRF-Var, <span class="hlt">model</span> background error (BE) is a key element required for the assimilation procedure. We have conducted an investigation into how varying the <span class="hlt">model</span> background error affects the results of assimilating in-situ surface observations. The background error covariances we tested include CV3 (a built-in global BE file in WRF-Var) and several domain-dependent CV5 BE files. The latter were calculated using 12-hourly forecast results and 24-hourly forecast over 2-month and 1-year periods, followed by the calculation of separate BE at 00, 06, 12, and 18 UTC, in order to capture the diurnal variation of the <span class="hlt">model</span> background error. The results show that the customized domain-dependent BE produces much better assimilation results than the global CV3 BE, and the CV5 BE calculated over a 1-year period additionally helps to improve the assimilation. When the diurnal variation of background error was included in the CV5 BE, a further improvement was achieved.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/27709956','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/27709956"><span><span class="hlt">Modeling</span> the Formation of Alkali Aluminosilicate Gels at the <span class="hlt">Mesoscale</span> Using Coarse-Grained Monte Carlo.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Yang, Kengran; White, Claire E</p> <p>2016-11-08</p> <p>Alkali-activated materials (AAMs) are currently being pursued as viable alternatives to conventional ordinary Portland cement because of their lower carbon footprint and established mechanical performance. However, our understanding of the <span class="hlt">mesoscale</span> morphology (∼1 to 100 nm) of AAMs and related amorphous aluminosilicate gels, including the development of the three-dimensional aluminosilicate network and nanoscale porosity, is severely limited. This study investigates the structural changes that occur during the formation of AAM gels at the <span class="hlt">mesoscale</span> by utilizing a coarse-grained Monte Carlo (CGMC) <span class="hlt">modeling</span> technique that exploits density functional theory calculations. The <span class="hlt">model</span> is capable of simulating the reaction of an aluminosilicate particle in a highly alkaline solution (sodium hydroxide or sodium silicate). Two precursor morphologies have been investigated (layered alumina and silica sheets mimicking metakaolin and spherical aluminosilicate particles reminiscent of coal-derived fly ash) to determine if the precursor morphology has an impact on the structural evolution of the resulting alkali-activated aluminosilicate gel. The CGMC <span class="hlt">model</span> can capture the three major stages of the alkali-activation process-dissolution, polycondensation, and reorganization-revealing that the dissolved silicate and aluminate species, ranging from monomers to nanoprecipitates (100s of monomers in size), exist in the pore solution of the hardened gel. The <span class="hlt">model</span> also reveals that the silica concentration of the activating solution controls the extent of dissolution of the precursor particle. From the analysis of the aluminosilicate cluster size distributions, the mechanisms of AAM gel growth have been elucidated, revealing that Ostwald ripening occurs in systems containing free silica at the start of the reaction. On the other hand, growth of the hydroxide-activated systems (metakaolin and fly ash) occurs via the formation of intermediate-sized clusters in addition to continual</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://cfpub.epa.gov/si/si_public_record_report.cfm?dirEntryId=146423&keyword=Wind+AND+sensors&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','EPA-EIMS'); return false;" href="http://cfpub.epa.gov/si/si_public_record_report.cfm?dirEntryId=146423&keyword=Wind+AND+sensors&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"><span>EXPERIMENTAL AND <span class="hlt">MODEL</span>-COMPUTED AREA AVERAGED VERTICAL PROFILES OF WIND SPEED FOR EVALUATION OF <span class="hlt">MESOSCALE</span> URBAN CANOPY SCHEMES</span></a></p> <p><a target="_blank" href="http://oaspub.epa.gov/eims/query.page">EPA Science Inventory</a></p> <p></p> <p></p> <p>Numerous urban canopy schemes have recently been developed for <span class="hlt">mesoscale</span> <span class="hlt">models</span> in order to approximate the drag and turbulent production effects of a city on the air flow. However, little data exists by which to evaluate the efficacy of the schemes since "area-averaged&quo...</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://cfpub.epa.gov/si/si_public_record_report.cfm?dirEntryId=146423&keyword=Michael+AND+Freeman&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=78124598&CFTOKEN=71577572','EPA-EIMS'); return false;" href="http://cfpub.epa.gov/si/si_public_record_report.cfm?dirEntryId=146423&keyword=Michael+AND+Freeman&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=78124598&CFTOKEN=71577572"><span>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> </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('https://www.fs.usda.gov/treesearch/pubs/30685','TREESEARCH'); return false;" href="https://www.fs.usda.gov/treesearch/pubs/30685"><span>A smoothed residual based goodness-of-fit statistic for <span class="hlt">nest</span>-survival <span class="hlt">models</span></span></a></p> <p><a target="_blank" href="http://www.fs.usda.gov/treesearch/">Treesearch</a></p> <p>Rodney X. Sturdivant; Jay J. Rotella; Robin E. Russell</p> <p>2008-01-01</p> <p>Estimating <span class="hlt">nest</span> success and identifying important factors related to <span class="hlt">nest</span>-survival rates is an essential goal for many wildlife researchers interested in understanding avian population dynamics. Advances in statistical methods have led to a number of estimation methods and approaches to <span class="hlt">modeling</span> this problem. Recently developed <span class="hlt">models</span> allow researchers to include a...</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2008AGUFMPA13C1350H','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2008AGUFMPA13C1350H"><span>The <span class="hlt">Nested</span> Regional Climate <span class="hlt">Model</span>: An Approach Toward Prediction Across Scales</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Hurrell, J. W.; Holland, G. J.; Large, W. G.</p> <p>2008-12-01</p> <p>The reality of global climate change has become accepted and society is rapidly moving to questions of consequences on space and time scales that are relevant to proper planning and development of adaptation strategies. There are a number of urgent challenges for the scientific community related to improved and more detailed predictions of regional climate change on decadal time scales. Two important examples are potential impacts of climate change on North Atlantic hurricane activity and on water resources over the intermountain West. The latter is dominated by complex topography, so that accurate simulations of regional climate variability and change require much finer spatial resolution than is provided with state-of-the-art climate <span class="hlt">models</span>. Climate <span class="hlt">models</span> also do not explicitly resolve tropical cyclones, even though these storms have dramatic societal impacts and play an important role in regulating climate. Moreover, the debate over the impact of global warming on tropical cyclones has at times been acrimonious, and the lack of hard evidence has left open opportunities for misinterpretation and justification of pre-existing beliefs. These and similar topics are being assessed at NCAR, in partnership with university colleagues, through the development of a <span class="hlt">Nested</span> Regional Climate <span class="hlt">Model</span> (NRCM). This is an ambitious effort to combine a state of the science <span class="hlt">mesoscale</span> weather <span class="hlt">model</span> (WRF), a high resolution regional ocean <span class="hlt">modeling</span> system (ROMS), and a climate <span class="hlt">model</span> (CCSM) to better simulate the complex, multi-scale interactions intrinsic to atmospheric and oceanic fluid motions that are limiting our ability to predict likely future changes in regional weather statistics and climate. The NRCM effort is attracting a large base of earth system scientists together with societal groups as diverse as the Western Governor's Association and the offshore oil industry. All of these groups require climate data on scales of a few kilometers (or less), so that the NRCM program is</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=20010072133&hterms=weather+predictions&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D50%26Ntt%3Dweather%2Bpredictions','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=20010072133&hterms=weather+predictions&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D50%26Ntt%3Dweather%2Bpredictions"><span>Assimilation of Combined Microwave and Lightning Measurement in a <span class="hlt">Mesoscale</span> Weather Prediction <span class="hlt">Model</span></span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Chang, Dong-Eon; Weinman, James A.; Busalacchi, Antonio J. (Technical Monitor)</p> <p>2000-01-01</p> <p>Intermittent measurements of precipitation and integrated water vapor (IWV) distributions were retrieved from the Special Sensor Microwave/Imager (SSM/I) and Tropical Rainfall Measuring Mission (TRMM) Microwave Imager (TMI) radiometers. Lightning generates very low frequency (VLF) radio noise pulses called sferics. Those pulses propagate over large distances so that they can be continuously monitored with a sparse network of ground based radio receivers. Sferics data, tuned with intermittent spaceborne microwave radiometer data, were used to generate estimated rainfall that was assimilated into a <span class="hlt">mesoscale</span> weather prediction <span class="hlt">model</span>. Both continuous latent heating adjustment and a variational technique are applied as assimilation procedures to evaluate the impact of lightning observations on the forecast of an intense winter squall line over the Gulf of Mexico. Sensitivities to the assimilation of additional measurements such as IWV and sea surface temperature (SST), and measurement errors will also be discussed.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2013AGUFMSA43C..07C','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2013AGUFMSA43C..07C"><span>The <span class="hlt">Mesoscale</span> Ionospheric Simulation Testbed (MIST) Regional Data Assimilation <span class="hlt">Model</span> (Invited)</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Comberiate, J.; Kelly, M. A.; Miller, E.; Paxton, L.</p> <p>2013-12-01</p> <p>The <span class="hlt">Mesoscale</span> Ionospheric Simulation Testbed (MIST) provides a regional nowcast and forecast of electron density values and has sufficient resolution to include equatorial plasma bubbles. The SSUSI instrument on the DMSP F18 satellite has high-resolution nightly observations of plasma bubbles at 8 PM local time throughout the current solar maximum. MIST can assimilate SSUSI UV observations, GPS TEC measurements, and SCINDA S4 readings simultaneously into a single scintillation map over a region of interest. MIST also <span class="hlt">models</span> ionospheric physics to provide a short-term UHF scintillation forecast based on assimilated data. We will present examples of electron density and scintillation maps from MIST. We will also discuss the potential to predict scintillation occurrence up to 6 hours in advance using observations of the equatorial arcs from SSUSI observations at 5:30 PM local time on the DMSP F17 satellite.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=20010072133&hterms=assimilation+procedure&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D20%26Ntt%3Dassimilation%2Bprocedure','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=20010072133&hterms=assimilation+procedure&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D20%26Ntt%3Dassimilation%2Bprocedure"><span>Assimilation of Combined Microwave and Lightning Measurement in a <span class="hlt">Mesoscale</span> Weather Prediction <span class="hlt">Model</span></span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Chang, Dong-Eon; Weinman, James A.; Busalacchi, Antonio J. (Technical Monitor)</p> <p>2000-01-01</p> <p>Intermittent measurements of precipitation and integrated water vapor (IWV) distributions were retrieved from the Special Sensor Microwave/Imager (SSM/I) and Tropical Rainfall Measuring Mission (TRMM) Microwave Imager (TMI) radiometers. Lightning generates very low frequency (VLF) radio noise pulses called sferics. Those pulses propagate over large distances so that they can be continuously monitored with a sparse network of ground based radio receivers. Sferics data, tuned with intermittent spaceborne microwave radiometer data, were used to generate estimated rainfall that was assimilated into a <span class="hlt">mesoscale</span> weather prediction <span class="hlt">model</span>. Both continuous latent heating adjustment and a variational technique are applied as assimilation procedures to evaluate the impact of lightning observations on the forecast of an intense winter squall line over the Gulf of Mexico. Sensitivities to the assimilation of additional measurements such as IWV and sea surface temperature (SST), and measurement errors will also be discussed.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=19990108738&hterms=combined+heating&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D10%26Ntt%3Dcombined%2Bheating','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=19990108738&hterms=combined+heating&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D10%26Ntt%3Dcombined%2Bheating"><span>Combined Microwave and Sferics Measurements as a Continuous Proxy for Latent Heating in <span class="hlt">Mesoscale</span> <span class="hlt">Model</span> Predictions</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Chang, D. -E.; Morales, C. A.; Weinman, J. A.; Olson, W. S.</p> <p>1999-01-01</p> <p>Planar rainfall distributions were retrieved from data provided by the Tropical Rainfall Measuring Mission (TRMM) Microwave Imager (TMI) and Special Sensor Microwave Imager (SSM/I) radiometers. Lightning generates Very Low Frequency (VLF) radio noise pulses called sferics. Those pulses propagate over large distances so that they can be continuously monitored with a network of ground based radio receivers. An empirical relationship between the sferics rate and the convective rainfall permitted maps of convective latent heating profiles to be derived continuously from the sferics distributions. Those inferred latent heating rates were assimilated into the Penn State/NCAR <span class="hlt">Mesoscale</span> <span class="hlt">Model</span> (MM5) that depicted an intense winter cyclone that passed over Florida on 2 February 1998. When compared to a 14 hour MM5 rainfall forecast using conventional data, the use of lightning data improved the forecast.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=19990053418&hterms=combined+heating&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D10%26Ntt%3Dcombined%2Bheating','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=19990053418&hterms=combined+heating&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D10%26Ntt%3Dcombined%2Bheating"><span>Combined Microwave and Sferics Measurements as a Continuous Proxy for Latent Heating in <span class="hlt">Mesoscale</span> <span class="hlt">Model</span> Predictions</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Chang, D.-E.; Morales, C. A.; Weinman, J. A.; Olson, W. S.</p> <p>1999-01-01</p> <p>Planar rainfall distributions were retrieved from data provided by the Tropical Rainfall Measuring Mission (TRMM) Microwave Imager (TMI) and Special Sensor Microwave/Imager (SSM/I) radiometers. Lightning generates Very Low Frequency (VLF) radio noise pulses called sferics. Those pulses propagate over large distances so that they can be continuously monitored with a network of ground based radio receivers. An empirical relationship between the sferics rate and the convective rainfall permitted maps of convective latent heating profiles to be derived continuously from the sferics distributions. Those inferred latent heating rates were assimilated into the Penn State/NCAR <span class="hlt">Mesoscale</span> <span class="hlt">Model</span> (MM5) that depicted an intense winter cyclone that passed over Florida on 2 February 1998. When compared to a 14 hour MM5 rainfall forecast using conventional data, the use of lightning data improved the forecast.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/27612204','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/27612204"><span>Probabilistic, Multivariable Flood Loss <span class="hlt">Modeling</span> on the <span class="hlt">Mesoscale</span> with BT-FLEMO.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Kreibich, Heidi; Botto, Anna; Merz, Bruno; Schröter, Kai</p> <p>2017-04-01</p> <p>Flood loss <span class="hlt">modeling</span> is an important component for risk analyses and decision support in flood risk management. Commonly, flood loss <span class="hlt">models</span> describe complex damaging processes by simple, deterministic approaches like depth-damage functions and are associated with large uncertainty. To improve flood loss estimation and to provide quantitative information about the uncertainty associated with loss <span class="hlt">modeling</span>, a probabilistic, multivariable Bagging decision Tree Flood Loss Estimation <span class="hlt">MOdel</span> (BT-FLEMO) for residential buildings was developed. The application of BT-FLEMO provides a probability distribution of estimated losses to residential buildings per municipality. BT-FLEMO was applied and validated at the <span class="hlt">mesoscale</span> in 19 municipalities that were affected during the 2002 flood by the River Mulde in Saxony, Germany. Validation was undertaken on the one hand via a comparison with six deterministic loss <span class="hlt">models</span>, including both depth-damage functions and multivariable <span class="hlt">models</span>. On the other hand, the results were compared with official loss data. BT-FLEMO outperforms deterministic, univariable, and multivariable <span class="hlt">models</span> with regard to <span class="hlt">model</span> accuracy, although the prediction uncertainty remains high. An important advantage of BT-FLEMO is the quantification of prediction uncertainty. The probability distribution of loss estimates by BT-FLEMO well represents the variation range of loss estimates of the other <span class="hlt">models</span> in the case study. © 2016 Society for Risk Analysis.</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>Projected changes of extreme precipitation over Contiguous United States with <span class="hlt">Nested</span> regional climate <span class="hlt">model</span> (NRCM)</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Wang, J.</p> <p>2013-12-01</p> <p>Extreme weather events have already significantly influenced North America. During 2005-2011, the extreme events have increased by 250 %, from four or fewer events occurring in 2005, while 14 events occurring in 2011 (www.ncdc.noaa.gov/billions/). In addition, extreme rainfall amounts, frequency, and intensity were all expected to increase under greenhouse warming scenarios (Wehner 2005; Kharin et al. 2007; Tebaldi et al. 2006). Global <span class="hlt">models</span> are powerful tools to investigate the climate and climate change on large scales. However, such <span class="hlt">models</span> do not represent local terrain and <span class="hlt">mesoscale</span> weather systems well owing to their coarse horizontal resolution (150-300 km). To capture the fine-scale features of extreme weather events, regional climate <span class="hlt">models</span> (RCMs) with a more realistic representation of the complex terrain and heterogeneous land surfaces are needed (Mass et al. 2002). This study uses the <span class="hlt">Nested</span> Regional Climate <span class="hlt">model</span> (NRCM) to perform regional scale climate simulations on a 12-km × 12-km high resolution scale over North America (including Alaska; with 600 × 515 grid cells at longitude and latitude), known as CORDEX_North America, instead of small regions as studied previously (eg., Dominguez et al. 2012; Gao et al. 2012). The performance and the biases of the NRCM extreme precipitation calculations (2000-2010) have been evaluated with PRISM precipitation (Daly et al. 1997) by Wang and Kotamarthi (2013): the NRCM replicated very well the monthly amount of extreme precipitation with less than 3% overestimation over East CONUS, and the frequency of extremes over West CONUS and upper Mississippi River Basin. The Representative Concentration Pathway (RCP) 8.5 and RCP 4.5 from the new Community Earth System <span class="hlt">Model</span> version 1.0 (CESM v1.0) are dynamically downscaled to predict the extreme rainfall events at the end-of-century (2085-2095) and to explore the uncertainties of future extreme precipitation induced by different scenarios over distinct regions. We have</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2004ACPD....4.5455L','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2004ACPD....4.5455L"><span><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://www.osti.gov/scitech/servlets/purl/5879503','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/servlets/purl/5879503"><span>MELSAR: a <span class="hlt">mesoscale</span> air quality <span class="hlt">model</span> for complex terrain. Volume 2. Appendices</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Allwine, K.J.; Whiteman, C.D.</p> <p>1985-04-01</p> <p>This final report is submitted as part of the Green River Ambient <span class="hlt">Model</span> Assessment (GRAMA) project conducted at the US Department of Energy's Pacific Northwest Laboratory for the US Environmental Protection Agency. The GRAMA Program has, as its ultimate goal, the development of validated air quality <span class="hlt">models</span> that can be applied to the complex terrain of the Green River Formation of western Colorado, eastern Utah and southern Wyoming. The Green River Formation is a geologic formation containing large reserves of oil shale, coal, and other natural resources. Development of these resources may lead to a degradation of the air quality of the region. Air quality <span class="hlt">models</span> are needed immediately for planning and regulatory purposes to assess the magnitude of these regional impacts. This report documents one of the <span class="hlt">models</span> being developed for this purpose within GRAMA - specifically a <span class="hlt">model</span> to predict short averaging time (less than or equal to 24 h) pollutant concentrations resulting from the <span class="hlt">mesoscale</span> transport of pollutant releases from multiple sources. MELSAR has not undergone any rigorous operational testing, sensitivity analyses, or validation studies. Testing and evaluation of the <span class="hlt">model</span> are needed to gain a measure of confidence in the <span class="hlt">model</span>'s performance. This report consists of two volumes. This volume contains the Appendices, which include listings of the FORTRAN code and Volume 1 contains the <span class="hlt">model</span> overview, technical description, and user's guide. 13 figs., 10 tabs.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015MolPh.113..898M','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015MolPh.113..898M"><span>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://pubs.er.usgs.gov/publication/70028853','USGSPUBS'); return false;" href="http://pubs.er.usgs.gov/publication/70028853"><span>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('https://www.ncbi.nlm.nih.gov/pubmed/21516903','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/21516903"><span>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.</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>High-Resolution <span class="hlt">Mesoscale</span> <span class="hlt">Model</span> Setup for the Eastern Range and Wallops Flight Facility</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Watson, Leela R.; Zavodsky, Bradley T.</p> <p>2015-01-01</p> <p><span class="hlt">Mesoscale</span> weather conditions can have an adverse effect on space launch, landing, ground processing, and weather advisories, watches, and warnings at the Eastern Range (ER) in Florida and Wallops Flight Facility (WFF) in Virginia. During summer, land-sea interactions across Kennedy Space Center (KSC) and Cape Canaveral Air Force Station (CCAFS) lead to sea breeze front formation, which can spawn deep convection that can hinder operations and endanger personnel and resources. Many other weak locally-driven low-level boundaries and their interactions with the sea breeze front and each other can also initiate deep convection in the KSC/CCAFS area. These convective processes often last 60 minutes or less and pose a significant challenge to the local forecasters. Surface winds during the transition seasons (spring and fall) pose the most difficulties for the forecasters at WFF. They also encounter problems forecasting convective activity and temperature during those seasons. Therefore, accurate <span class="hlt">mesoscale</span> <span class="hlt">model</span> forecasts are needed to better forecast a variety of unique weather phenomena. Global and national scale <span class="hlt">models</span> cannot properly resolve important local-scale weather features at each location due to their horizontal resolutions being much too coarse. Therefore, a properly tuned local data assimilation (DA) and forecast <span class="hlt">model</span> at a high resolution is needed to provide improved capability. To accomplish this, a number of sensitivity tests were performed using the Weather Research and Forecasting (WRF) <span class="hlt">model</span> in order to determine the best DA/<span class="hlt">model</span> configuration for operational use at each of the space launch ranges to best predict winds, precipitation, and temperature. A set of Perl scripts to run the Gridpoint Statistical Interpolation (GSI)/WRF in real-time were provided by NASA's Short-term Prediction Research and Transition Center (SPoRT). The GSI can analyze many types of observational data including satellite, radar, and conventional data. The GSI/WRF scripts</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015EGUGA..17.2729C','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015EGUGA..17.2729C"><span>What can we learn from the hydrological <span class="hlt">modeling</span> of small-scale catchments for the discharge and water balance <span class="hlt">modeling</span> of <span class="hlt">mesoscale</span> catchments?</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Cornelissen, Thomas; Diekkrüger, Bernd; Bogena, Heye</p> <p>2015-04-01</p> <p>The application of 3D hydrological <span class="hlt">models</span> remains a challenge both in research and application studies because the parameterization not only depends on the amount and quality of data available for calibration and validation but also on the spatial and temporal <span class="hlt">model</span> resolution. In recent years, the <span class="hlt">model</span> parameterization has improved with the availability of high resolution data (e.g. eddy-covariance, wireless soil sensor networks). Unfortunately, these high resolution data are typically only available for small scale research test sites. This study aims to upscale the parameterization from a highly equipped, small-scale catchment to a <span class="hlt">mesoscale</span> catchment in order to reduce the parameterization uncertainty at that scale. The two <span class="hlt">nested</span> catchments chosen for the study are the 0.38 km² large spruce covered Wüstebach catchment and the 42 km² large Erkensruhr catchment characterized by a mixture of spruce and beech forest and grassland vegetation. The 3D hydrogeological <span class="hlt">model</span> HydroGeoSphere (HGS) has already been setup for the Wüstebach catchment in a previous study with a focus on the simulation performance of soil water dynamics and patterns. Thus, the parameterization process did not only optimize the water balance components but the catchment's wireless soil sensor network data were utilized to calibrate porosities in order to improve the simulation of soil moisture dynamics. In this study we compared different HGS <span class="hlt">model</span> realizations for the Erkensruhr catchment with different input data. For the first <span class="hlt">model</span> realization, the catchment is treated heterogeneous in terms of soil properties and topography but homogeneous with respect to land use, precipitation and potential evapotranspiration. For this case, the spruce forest parameterization and the climate input data were taken directly from the small-scale Wüstebach <span class="hlt">model</span> realization. Next, the calibrated soil porosity for the Wüstebach catchment is applied to the Erkensruhr. Further <span class="hlt">model</span> realizations</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016AGUFM.A21F0140H','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016AGUFM.A21F0140H"><span>A Prototype Nonhydrostatic Regional-to-Global <span class="hlt">Nested</span>-Grid Atmosphere <span class="hlt">Model</span> for Medium-range Weather Forecasting</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Harris, L.; Lin, S. J.; Zhou, L.; Chen, J. H.; Benson, R.; Rees, S.</p> <p>2016-12-01</p> <p>Limited-area convection-permitting <span class="hlt">models</span> have proven useful for short-range NWP, but are unable to interact with the larger scales needed for longer lead-time skill. A new global forecast <span class="hlt">model</span>, fvGFS, has been designed combining a modern nonhydrostatic dynamical core, the GFDL Finite-Volume Cubed-Sphere dynamical core (FV3) with operational GFS physics and initial conditions, and has been shown to provide excellent global skill while improving representation of small-scale phenomena. The <span class="hlt">nested</span>-grid capability of FV3 allows us to build a regional-to-global variable-resolution <span class="hlt">model</span> to efficiently refine to 3-km grid spacing over the Continental US. The use of two-way grid <span class="hlt">nesting</span> allows us to reach these resolutions very efficiently, with the operational requirement easily attainable on current supercomputing systems.Even without a boundary-layer or advanced microphysical scheme appropriate for convection-perrmitting resolutions, the effectiveness of fvGFS can be demonstrated for a variety of weather events. We demonstrate successful proof-of-concept simulations of a variety of phenomena. We show the capability to develop intense hurricanes with realistic fine-scale eyewalls and rainbands. The new <span class="hlt">model</span> also produces skillful predictions of severe weather outbreaks and of organized <span class="hlt">mesoscale</span> convective systems. Fine-scale orographic and boundary-layer phenomena are also simulated with excellent fidelity by fvGFS. Further expected improvements are discussed, including the introduction of more sophisticated microphysics and of scale-aware convection schemes.</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>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/abs/2014AGUFMEP11B..07C','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014AGUFMEP11B..07C"><span>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('https://ntrs.nasa.gov/search.jsp?R=20100031067&hterms=momentum&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D20%26Ntt%3Dmomentum','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=20100031067&hterms=momentum&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D20%26Ntt%3Dmomentum"><span>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> </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://adsabs.harvard.edu/abs/2011ACP....11.2951F','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2011ACP....11.2951F"><span>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://adsabs.harvard.edu/abs/2010ACPD...1025909F','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2010ACPD...1025909F"><span>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('https://ntrs.nasa.gov/search.jsp?R=20100031067&hterms=PBL&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D60%26Ntt%3DPBL','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=20100031067&hterms=PBL&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D60%26Ntt%3DPBL"><span>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/2004BAMS...85..709W','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2004BAMS...85..709W"><span>A Rapidly Deployable Operational <span class="hlt">Mesoscale</span> <span class="hlt">Modeling</span> System for Emergency-Response Applications.</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Warner, Thomas T.; Bowers, James F.; Swerdlin, Scott P.; Beitler, Brian A.</p> <p>2004-05-01</p> <p>An operational <span class="hlt">mesoscale</span> <span class="hlt">model</span> based forecasting system has been developed for use by U.S. Army Test and Evaluation Command meteorologists in their support of test-range operations. This paper reports on the adaptation of this system to permit its rapid deployment in support of a variety of civilian and military emergency-response applications. The innovation that allows for this rapid deployment is an intuitive graphical user interface that permits a non-expert to quickly configure the <span class="hlt">model</span> for a new application, and launch the forecast system to produce operational products without further intervention. The graphical interface is Web based and can be run on a wireless laptop or a personal digital assistant in the field. The instructions for configuring the <span class="hlt">modeling</span> system are transmitted to a compute engine [generally a personal computer (PC) cluster], and forecast products are placed on a Web site that can be accessed by emergency responders or other forecast users. This system has been used operationally for predicting the potential transport and dispersion of hazardous material during the 2002 Winter Olympics in Salt Lake City, Utah, and during military operations in Afghanistan. It has also been used operationally to satisfy the rapidly evolving needs of wildfire managers. Continued use of the <span class="hlt">modeling</span> system by nonexperts will allow developers to refine the graphical interface and make the <span class="hlt">model</span> and the interface more fault tolerant with respect to the decisions of <span class="hlt">model</span> users.(The National Center for Atmospheric Research is sponsored by the National Science Foundation</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017EGUGA..19.7192B','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017EGUGA..19.7192B"><span>Stochastic parametrization of <span class="hlt">model</span> errors using <span class="hlt">nested</span> <span class="hlt">model</span> in the context of data assimilation</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Barth, Alexander; Vandenbulcke, Luc; Alvera Azcarate, Aida; Beckers, Jean-Marie</p> <p>2017-04-01</p> <p>A major difficulty in data assimilation is to adequately specify the <span class="hlt">model</span> error covariances. For ensemble assimilation schemes all uncertain aspects of the <span class="hlt">model</span> would need to be perturbed within their range of uncertainty. While progress have been made to address the error source external to an ocean <span class="hlt">model</span>, such as atmospheric fields, bathymetry and boundary conditions, the intrinsic <span class="hlt">model</span> error is rarely addressed. The objective of the study is to improve our knowledge on the intrinsic <span class="hlt">model</span> error due to the finite resolution and to propose statistical parameterization usable in ensemble simulations. To study the impact of resolution on the <span class="hlt">model</span> simulation, a two-way <span class="hlt">nested</span> ROMS <span class="hlt">model</span> is implemented. The <span class="hlt">modelling</span> system is composed by a Ligurian Sea <span class="hlt">model</span> at 1/60 degree <span class="hlt">nested</span> in the CMEMS Mediterranean <span class="hlt">Model</span> (one-way). A high-resolution NW Corsican <span class="hlt">model</span> at 1/180 degree (about 530 m) is <span class="hlt">nested</span> in the Ligurian Sea <span class="hlt">model</span> (two-way). The fact that the <span class="hlt">model</span> equations are solved twice provides an interesting opportunity to gain some insight about the <span class="hlt">model</span> error due to resolution and to derive an empirical stochastic parametrization of subgrid-scale processes. During the two-way <span class="hlt">nesting</span> feedback, the difference between the coarse <span class="hlt">model</span> grid and the averaged fine <span class="hlt">model</span> result is computed. The statistical properties of the feedback increment is studied and related to the parameters resolved on the coarse <span class="hlt">model</span> grid. In favorable cases, a significant part of the variance of the feedback increment can be related to fronts also resolved in the coarse <span class="hlt">model</span> grid which allows to derive empirical statistical parameterizations of the subgrid scale processes.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2009AGUFM.H41F0959S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2009AGUFM.H41F0959S"><span>Conditioning of a <span class="hlt">mesoscale</span> hydrologic <span class="hlt">model</span> with proxy soil moisture fields</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Samaniego-Eguiguren, L. E.; Bardossy, A.; Kumar, R.</p> <p>2009-12-01</p> <p>Multiscale monitoring and data assimilation techniques are fundamental to improve the predictability of <span class="hlt">mesoscale</span> distributed hydrologic <span class="hlt">models</span>. In-situ measurements along with remote sensed information can be used to condition the parametrization of distributed <span class="hlt">models</span> aiming at reducing their prediction uncertainty of both energy and mass balances. One of the key state variables responsible for the feedback mechanisms in the land-surface-atmosphere system is the soil moisture. This variable, on the contrary to other water fluxes, has a long memory and depends greatly on local conditions. The spatial distribution of soil moisture is therefore crucial to determine the spatial patterns of both surface runoff and actual evaporation. There are a number of proxies that can be used to describe the evolution of this state variable. They can be obtained at different resolutions, for example, the land surface temperature of the MODIS (NASA) sensor (1 x 1) km or the surface soil moisture (SSM) data based on ERS and METOP scatterometers (12.5 x 12.5) km. In this study we develop local-neighborhood estimators that help to constrain the spatio-temporal evolution of the top-layer soil moisture during a period of time. These estimators are included in the calibration process as a penalty function. The <span class="hlt">mesoscale</span> hydrologic <span class="hlt">model</span> (mHM) employed in this study is forced with (1 x 1) km daily meteorological variables such as precipitation, temperature and potential evapotranspiration. All parameters of mHM were regionalized with a multi-scale parametrization technique. The <span class="hlt">model</span> was set up in the Neckar Basin in south Germany for the period 2001 to 2007, from which the first four years were used for calibration. The spin up period of the <span class="hlt">model</span> was from 1992 to 2001. The search of good parameter sets was carried out with simulated annealing. Multiscale conditioning of soil moisture states in addition to the commonly used streamflow data lead to a significant reduction of the</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>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://adsabs.harvard.edu/abs/1992PhDT........45Y','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/1992PhDT........45Y"><span>Impact of a Newtonian Assimilation and Physical Initialization on the Initialization and Prediction in a Tropical <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>Yap, Kok-Seng</p> <p></p> <p>One of the major limitations of tropical hydrostatic <span class="hlt">mesoscale</span> <span class="hlt">models</span> initialized through synoptic and subsynoptic scale data and operating on a grid resolution of 20-50km is that they show limited skill in simulating the spatial and temporal distribution of precipitation despite well -predicted synoptic and subsynoptic-scale flow patterns. In general the <span class="hlt">models</span> show a precipitation spin-up phase, however once activated, the <span class="hlt">model</span> tends to become convectively overactive through the synoptic scale-<span class="hlt">mesoscale</span> feedback mechanism. Our experience suggests that for the tropics where the <span class="hlt">mesoscale</span> circulations are convectively active, the precipitation spin-up arises from the inability of the initial synoptic-scale analysis to produce dynamic, thermodynamic and moisture fields capable of supporting convection on the <span class="hlt">mesoscale</span>. In particular, the problem lies in the wrong initial analysis of the velocity divergence and moisture fields. The overactive convection in the <span class="hlt">model</span> arises when the <span class="hlt">model</span> fails to initiate convection over some of the areas that are observed to precipitate, hence feeding the available moisture into the <span class="hlt">model</span> activated regions. It is shown in this study that this spin-up and overactive convection problem can be overcome by carrying out a dynamic Newtonian assimilation coupled with physical initialization during a preforecast integration phase of the <span class="hlt">model</span>. In particular it is shown that the Newtonian assimilation of the rotational component of the wind and surface pressure coupled with physical initialization of surface fluxes of moisture, cumulus parameterization and outgoing longwave radiation (OLR) enables the <span class="hlt">model</span> to build the divergence and moisture fields at the required location. The cumulus initialization is done through a humidity reanalysis via a "Reverse Kuo" algorithm. The surface latent heat flux initialization is done by reanalysis of the <span class="hlt">model</span>'s lowest level humidity fields through a "Reverse similarity algorithm", and the OLR</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>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/2009AGUFM.A33H..03E','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2009AGUFM.A33H..03E"><span>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('https://ntrs.nasa.gov/search.jsp?R=19890031821&hterms=sea+breeze&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D10%26Ntt%3Dsea%2Bbreeze','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=19890031821&hterms=sea+breeze&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D10%26Ntt%3Dsea%2Bbreeze"><span>Providing operational guidance for the development of sea breeze thunderstorms at the Kennedy Space Center - An experiment using a <span class="hlt">mesoscale</span> numerical <span class="hlt">model</span></span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Lyons, Walter A.; Moon, Dennis A.; Keen, Cecil S.; Schuh, Jerome A.; Pielke, Roger A.</p> <p>1988-01-01</p> <p>The effectiveness of a <span class="hlt">mesoscale</span> numerical <span class="hlt">model</span> to provide improved local forecast guidance is evaluated with respect to sea breeze convection storms at the Kennedy Space Center. The <span class="hlt">model</span> and operational forecast guidance production are described. A case study is presented for sea breeze convection storms and lightning events on July 1, 1986. It is found that the <span class="hlt">mesoscale</span> numerical <span class="hlt">model</span> outperforms purely subjective predictions of sea breeze convection. The range of applications for the <span class="hlt">model</span> are considered.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2011AGUFM.T54A..05H','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2011AGUFM.T54A..05H"><span>Experimental observations and a <span class="hlt">mesoscale</span> constitutive <span class="hlt">model</span> of rocks undergoing stress-driven melt segregation</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Holtzman, B. K.; King, D. S.; Kohlstedt, D. L.</p> <p>2011-12-01</p> <p>Coupling between deformation and melt transport have long been recognized in field observations and inferred to be important in the dynamics of crustal and lithosphere dynamics. We are studying these processes with closely knit experimental and theoretical approaches. Here, we present a synthesis of experimental observations of strain weakening associated with strain partitioning in networks of melt-rich shear zones. Variability in the mechanical data from torsion experiments reflect different degrees of melt segregation, due to different material properties, stress levels and boundary conditions (constant torque or constant twist rate). To explore this variability in more detail, we develop a <span class="hlt">mesoscale</span> constitutive <span class="hlt">model</span> that treats segregation as a process occurring within the representative elementary volume, described by internal state variables. This constitutive <span class="hlt">model</span> is comprised of several aspects, including 1) mass balance, 2) mechanical energy balance, and 3) an evolution equation for a single internal state variable describing the degree of melt segregation. At present, the evolution equation is relatively empirical, designed to allow us to quantify the sensitivity of the segregation rate to stress levels. These variations can be seen in the macroscopic creep data as well as the melt distribution within the torsion sample, which contains a continuous range of mechanical conditions from center to edge. The constitutive <span class="hlt">model</span> is formulated for easy implementation in numerical <span class="hlt">models</span>, in conjunction with common stress-, grain size- and temperature-dependent flow laws.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/servlets/purl/1366459','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/servlets/purl/1366459"><span><span class="hlt">Mesoscale</span> <span class="hlt">model</span> for fission-induced recrystallization in U-7Mo alloy</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Liang, Linyun; Mei, Zhi -Gang; Kim, Yeon Soo; Ye, Bei; Hofman, Gerard; Anitescu, Mihai; Yacout, Abdellatif M.</p> <p>2016-08-09</p> <p>A <span class="hlt">mesoscale</span> <span class="hlt">model</span> is developed by integrating the rate theory and phase-field <span class="hlt">models</span> and is used to study the fission-induced recrystallization in U-7Mo alloy. The rate theory <span class="hlt">model</span> is used to predict the dislocation density and the recrystallization nuclei density due to irradiation. The predicted fission rate and temperature dependences of the dislocation density are in good agreement with experimental measurements. This information is used as input for the multiphase phase-field <span class="hlt">model</span> to investigate the fission-induced recrystallization kinetics. The simulated recrystallization volume fraction and bubble induced swelling agree well with experimental data. The effects of the fission rate, initial grain size, and grain morphology on the recrystallization kinetics are discussed based on an analysis of recrystallization growth rate using the modified Avrami equation. Here, we conclude that the initial microstructure of the U-Mo fuels, especially the grain size, can be used to effectively control the rate of fission-induced recrystallization and therefore swelling.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2003AtmEn..37.2451V','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2003AtmEn..37.2451V"><span>A <span class="hlt">mesoscale</span> <span class="hlt">modeling</span> study of wind blown dust on the Mexico City Basin</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Villasenor, Rafael; López-Villegas, M. T.; Eidels-Dubovoi, S.; Quintanar, Arturo; Gallardo, J. C.</p> <p></p> <p>The latest phase of the program to improve the air quality in the Valley of Mexico, also known, as Pro Aire is about to go into effect for the next 10 years. Pro Aire puts emphasis on agricultural wind erosion and associated dust emissions impacting downwind air quality. The main objective of this investigation was to use an empirical USEPA erosion <span class="hlt">model</span> coupled to a meteorological/transport-dispersion prediction <span class="hlt">model</span>, CALMET/CALPUFF, to estimate dust emissions and concentrations in the Mexico City Basin. The <span class="hlt">model</span> simulations for particulate matter (PM 10) are validated against observations taken at the most recent research field study, the IMADA-AVER field campaign, conducted during the spring of 1997 to provide information about high ozone, particulate matter concentrations and visibility impairment. The spatial and temporal PM distribution in the region is presented for a specific wind blown dust event consisting of two IMADA days, in order to understand how soil dust emissions from agricultural fallow land affect downwind areas during the dry season. Results show good agreement with the main spatial features of the local wind circulation and wind blown dust concentrations. A correlation coefficient of nearly 0.8 between predictions and observations for a <span class="hlt">modeled</span> day suggests that an important portion of the total measured concentration had geological origin. This work constitutes an essential advancement on the <span class="hlt">mesoscale</span> air quality problem on the MCMA due to wind erosion.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/pages/biblio/1366459-mesoscale-model-fission-induced-recrystallization-alloy','SCIGOV-DOEP'); return false;" href="https://www.osti.gov/pages/biblio/1366459-mesoscale-model-fission-induced-recrystallization-alloy"><span><span class="hlt">Mesoscale</span> <span class="hlt">model</span> for fission-induced recrystallization in U-7Mo alloy</span></a></p> <p><a target="_blank" href="http://www.osti.gov/pages">DOE PAGES</a></p> <p>Liang, Linyun; Mei, Zhi -Gang; Kim, Yeon Soo; ...</p> <p>2016-08-09</p> <p>A <span class="hlt">mesoscale</span> <span class="hlt">model</span> is developed by integrating the rate theory and phase-field <span class="hlt">models</span> and is used to study the fission-induced recrystallization in U-7Mo alloy. The rate theory <span class="hlt">model</span> is used to predict the dislocation density and the recrystallization nuclei density due to irradiation. The predicted fission rate and temperature dependences of the dislocation density are in good agreement with experimental measurements. This information is used as input for the multiphase phase-field <span class="hlt">model</span> to investigate the fission-induced recrystallization kinetics. The simulated recrystallization volume fraction and bubble induced swelling agree well with experimental data. The effects of the fission rate, initial grainmore » size, and grain morphology on the recrystallization kinetics are discussed based on an analysis of recrystallization growth rate using the modified Avrami equation. Here, we conclude that the initial microstructure of the U-Mo fuels, especially the grain size, can be used to effectively control the rate of fission-induced recrystallization and therefore swelling.« less</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>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://adsabs.harvard.edu/abs/2017AdSR...14..195R','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017AdSR...14..195R"><span>The HIRLAM fast radiation scheme for <span class="hlt">mesoscale</span> numerical weather prediction <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>Rontu, Laura; Gleeson, Emily; Räisänen, Petri; Pagh Nielsen, Kristian; Savijärvi, Hannu; Hansen Sass, Bent</p> <p>2017-07-01</p> <p>This paper provides an overview of the HLRADIA shortwave (SW) and longwave (LW) broadband radiation schemes used in the HIRLAM numerical weather prediction (NWP) <span class="hlt">model</span> and available in the HARMONIE-AROME <span class="hlt">mesoscale</span> NWP <span class="hlt">model</span>. The advantage of broadband, over spectral, schemes is that they can be called more frequently within the <span class="hlt">model</span>, without compromising on computational efficiency. In <span class="hlt">mesoscale</span> <span class="hlt">models</span> fast interactions between clouds and radiation and the surface and radiation can be of greater importance than accounting for the spectral details of clear-sky radiation; thus calling the routines more frequently can be of greater benefit than the deterioration due to loss of spectral details. Fast but physically based radiation parametrizations are expected to be valuable for high-resolution ensemble forecasting, because as well as the speed of their execution, they may provide realistic physical perturbations. Results from single-column diagnostic experiments based on CIRC benchmark cases and an evaluation of 10 years of radiation output from the FMI operational archive of HIRLAM forecasts indicate that HLRADIA performs sufficiently well with respect to the clear-sky downwelling SW and longwave LW fluxes at the surface. In general, HLRADIA tends to overestimate surface fluxes, with the exception of LW fluxes under cold and dry conditions. The most obvious overestimation of the surface SW flux was seen in the cloudy cases in the 10-year comparison; this bias may be related to using a cloud inhomogeneity correction, which was too large. According to the CIRC comparisons, the outgoing LW and SW fluxes at the top of atmosphere are mostly overestimated by HLRADIA and the net LW flux is underestimated above clouds. The absorption of SW radiation by the atmosphere seems to be underestimated and LW absorption seems to be overestimated. Despite these issues, the overall results are satisfying and work on the improvement of HLRADIA for the use in HARMONIE-AROME NWP system</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017PhRvE..95e2411R','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017PhRvE..95e2411R"><span><span class="hlt">Model</span> of the best-of-N <span class="hlt">nest</span>-site selection process in honeybees</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Reina, Andreagiovanni; Marshall, James A. R.; Trianni, Vito; Bose, Thomas</p> <p>2017-05-01</p> <p>The ability of a honeybee swarm to select the best <span class="hlt">nest</span> site plays a fundamental role in determining the future colony's fitness. To date, the <span class="hlt">nest</span>-site selection process has mostly been <span class="hlt">modeled</span> and theoretically analyzed for the case of binary decisions. However, when the number of alternative <span class="hlt">nests</span> is larger than two, the decision-process dynamics qualitatively change. In this work, we extend previous analyses of a value-sensitive decision-making mechanism to a decision process among N <span class="hlt">nests</span>. First, we present the decision-making dynamics in the symmetric case of N equal-quality <span class="hlt">nests</span>. Then, we generalize our findings to a best-of-N decision scenario with one superior <span class="hlt">nest</span> and N -1 inferior <span class="hlt">nests</span>, previously studied empirically in bees and ants. Whereas previous binary <span class="hlt">models</span> highlighted the crucial role of inhibitory stop-signaling, the key parameter in our new analysis is the relative time invested by swarm members in individual discovery and in signaling behaviors. Our new analysis reveals conflicting pressures on this ratio in symmetric and best-of-N decisions, which could be solved through a time-dependent signaling strategy. Additionally, our analysis suggests how ecological factors determining the density of suitable <span class="hlt">nest</span> sites may have led to selective pressures for an optimal stable signaling ratio.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=19930055785&hterms=sea+breeze&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D10%26Ntt%3Dsea%2Bbreeze','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=19930055785&hterms=sea+breeze&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D10%26Ntt%3Dsea%2Bbreeze"><span>Final results of an experiment in operational forecasting of sea breeze thunderstorms using a <span class="hlt">mesoscale</span> numerical <span class="hlt">model</span></span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Lyons, Walter A.; Pielke, Roger A.; Cotton, William R.; Keen, Cecil S.; Moon, Dennis A.</p> <p>1992-01-01</p> <p>Sea breeze thunderstorms during quiescent synoptic conductions account for 40 percent of Florida rainfall, and are the dominant feature of April-October weather at the Kennedy Space Center (KSC). An effort is presently made to assess the feasibility of a <span class="hlt">mesoscale</span> numerical <span class="hlt">model</span> in improving the point-specific thunderstorm forecasting accuracy at the KSC, in the 2-12 hour time frame. Attention is given to the Applied Regional Atmospheric <span class="hlt">Modeling</span> System.</p> </li> <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>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> </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/1999JApMe..38.1311S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/1999JApMe..38.1311S"><span>Horizontal Grid Size Selection and its Influence 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>Salvador, Rosa; Calbó, Josep; Millán, Millán M.</p> <p>1999-09-01</p> <p>The use of two-dimensional spectral analysis applied to terrain heights in order to determine characteristic terrain spatial scales and its subsequent use for the objective definition of an adequate grid size required to resolve terrain forcing are presented in this paper. In order to illustrate the influence of grid size, atmospheric flow in a complex terrain area of the Spanish east coast is simulated by the Regional Atmospheric <span class="hlt">Modeling</span> System (RAMS) <span class="hlt">mesoscale</span> numerical <span class="hlt">model</span> using different horizontal grid resolutions. In this area, a grid size of 2 km is required to account for 95% of terrain variance. Comparison among results of the different simulations shows that, although the main wind behavior does not change dramatically, some small-scale features appear when using a resolution of 2 km or finer. Horizontal flow pattern differences are significant both in the nighttime, when terrain forcing is more relevant, and in the daytime, when thermal forcing is dominant. Vertical structures also are investigated, and results show that vertical advection is influenced highly by the horizontal grid size during the daytime period. The turbulent kinetic energy and potential temperature vertical cross sections show substantial differences in the structure of the planetary boundary layer for each <span class="hlt">model</span> configuration.</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>Multiphase <span class="hlt">Modeling</span> of Flow, Transport, and Biodegradation in a <span class="hlt">Mesoscale</span> Landfill Bioreactor</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Oldenburg, Curtis M.; Borglin, Sharon E.; Hazen, Terry C.</p> <p>2002-02-01</p> <p>The need to control gas and leachate production and minimize refuse volume in municipal solid waste landfills has motivated the development of landfill simulation <span class="hlt">models</span> to predict and design optimal treatment processes. We have developed a multiphase and multicomponent nonisothermal module called T2LBM for the three-dimensional TOUGH2 flow and transport simulator. T2LBM can be used to simulate aerobic or anaerobic biodegradation of municipal solid waste and the associated flow and transport of gas and liquid through the refuse mass. Acetic acid is used as a proxy for all biodegradable substrates in the refuse. T2LBM incorporates a Monod kinetic rate law for the biodegradation of acetic acid by either aerobic or anaerobic microbes as controlled by the local oxygen concentration. We have verified the <span class="hlt">model</span> against published data, and applied it to our own <span class="hlt">mesoscale</span> laboratory aerobic landfill bioreactor experiments. We observe spatial variability of flow and biodegradation consistent with permeability heterogeneity and the geometry of the radial grid. The <span class="hlt">model</span> is capable of matching results of a shut-in test where the respiration of the system is measured over time.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2006AGUFM.A32D..08N','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2006AGUFM.A32D..08N"><span>Dissecting the 7 July 2004 storm over Baltimore, MD: <span class="hlt">Mesoscale</span> <span class="hlt">modeling</span> and observations</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Ntelekos, A. A.; Smith, J. A.; Baeck, M. L.; Miller, A. J.</p> <p>2006-12-01</p> <p>On 7 July 2004, the Baltimore metropolitan region experienced a thunderstorm system that produced record flooding, rainfall and cloud-to-ground lightning strikes. In this study, <span class="hlt">model</span> and observational analyses are carried out to analyze the hydrometeorology of the storm and understand the impacts of the urban environment and surrounding topography on storm evolution. Baltimore is an interesting setting for these analyses combining the urban environment with mountainous terrain to the west and the land-water interface to the east. Hydrometeorological analyses are based on volume scan reflectivity observations from the Baltimore International Airport Terminal Doppler Weather Radar and the Sterling, Virginia WSR-88D radar, cloud-to- ground lightning observations from the National Lightning Detection Network, raindrop spectra observations from a Joss-Waldvogel disdrometer and rainfall accumulations from a dense rain gage network operated as a component of the Baltimore Ecosystem Study. Numerical <span class="hlt">model</span> analyses use the Weather Research Forecast (WRF) <span class="hlt">mesoscale</span> <span class="hlt">model</span> to examine the impact of land-use, topography and land-water boundaries on the initiation and evolution of the storm.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2007PApGe.164.1161G','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2007PApGe.164.1161G"><span>Microphysical Observations and <span class="hlt">Mesoscale</span> <span class="hlt">Model</span> Simulation of a Warm Fog Case during FRAM Project</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Gultepe, I.; Milbrandt, J. A.</p> <p>2007-06-01</p> <p>The objective of this work is to apply a new microphysical parameterization for fog visibility for potential use in numerical weather forecast simulations, and to compare the results with ground-based observations. The observations from the Fog Remote Sensing And <span class="hlt">Modeling</span> (FRAM) field which took place during the winter of 2005 2006 over southern Ontario, Canada (Phase I) were used in the analysis. The liquid water content (LWC), droplet number concentration (N d ), and temperature (T) were obtained from the fog measuring device (FMD) spectra and Rosemount probe, correspondingly. The visibility (Vis) from a visibility meter, liquid water path from microwave radiometers (MWR), and inferred fog properties such as mean volume diameter, LWC, and N d were also used in the analysis. The results showed that Vis is nonlinearly related to both LWC and N d . Comparisons between newly derived parameterizations and the ones already in use as a function of LWC suggested that if <span class="hlt">models</span> can predict the total N d and LWC at each time step using a detailed microphysics parameterization, Vis can then be calculated for warm fog conditions. Using outputs from the Canadian <span class="hlt">Mesoscale</span> Compressible Community (MC2) <span class="hlt">model</span>, being tested with a new multi-moment bulk microphysical scheme, the new Vis parameterization resulted in more accurate Vis values where the correction reached up to 20 50%.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2007AGUFM.H13F1653G','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2007AGUFM.H13F1653G"><span>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('https://www.ncbi.nlm.nih.gov/pubmed/27570365','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/27570365"><span><span class="hlt">Mesoscale</span> analysis of failure in quasi-brittle materials: comparison between lattice <span class="hlt">model</span> and acoustic emission data.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Grégoire, David; Verdon, Laura; Lefort, Vincent; Grassl, Peter; Saliba, Jacqueline; Regoin, Jean-Pierre; Loukili, Ahmed; Pijaudier-Cabot, Gilles</p> <p>2015-10-25</p> <p>The purpose of this paper is to analyse the development and the evolution of the fracture process zone during fracture and damage in quasi-brittle materials. A <span class="hlt">model</span> taking into account the material details at the <span class="hlt">mesoscale</span> is used to describe the failure process at the scale of the heterogeneities. This <span class="hlt">model</span> is used to compute histograms of the relative distances between damaged points. These numerical results are compared with experimental data, where the damage evolution is monitored using acoustic emissions. Histograms of the relative distances between damage events in the numerical calculations and acoustic events in the experiments exhibit good agreement. It is shown that the <span class="hlt">mesoscale</span> <span class="hlt">model</span> provides relevant information from the point of view of both global responses and the local failure process. © 2015 The Authors. International Journal for Numerical and Analytical Methods in Geomechanics published by John Wiley & Sons Ltd.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=19880001942&hterms=sea+breeze&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D10%26Ntt%3Dsea%2Bbreeze','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=19880001942&hterms=sea+breeze&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D10%26Ntt%3Dsea%2Bbreeze"><span>Short range forecasting of sea breeze generated thunderstorms at the Kennedy Space Center: A real-time experiment using a primitive equation <span class="hlt">mesoscale</span> numerical <span class="hlt">model</span></span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Lyons, Walter A.; Schuh, Jerome A.; Moon, Dennis; Pielke, Roger A.; Cotton, William; Arritt, Raymond</p> <p>1987-01-01</p> <p>The operational efficiency of using guidance from a <span class="hlt">mesoscale</span> numerical <span class="hlt">model</span> to improve sea breeze thunderstorm forecasts at and around the Shuttle landing strip was assessed. The Prognostic Three-Dimensional <span class="hlt">Mesoscale</span> (P3DM) <span class="hlt">model</span>, developed as a sea breeze <span class="hlt">model</span>, reveals a strong correlation between regions of <span class="hlt">mesoscale</span> convergence and the triggering of sea breeze convection thunderstorms. The P3DM was modified to generate stability parameters familiar to the operational forecaster. In addition to the <span class="hlt">mesoscale</span> fields of wind, vertical motion, moisture, temperature, a stability indicator, a combination of <span class="hlt">model</span>-predicted K and Lifted Indices and the maximum grid cell vertical motion, were proposed and tested. Results of blind tests indicate that a forecaster, provided with guidance derived from <span class="hlt">model</span> output, could improve local thunderstorm forecasts.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=19880001942&hterms=range+equation&qs=N%3D0%26Ntk%3DAll%26Ntx%3Dmode%2Bmatchall%26Ntt%3Drange%2Bequation','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=19880001942&hterms=range+equation&qs=N%3D0%26Ntk%3DAll%26Ntx%3Dmode%2Bmatchall%26Ntt%3Drange%2Bequation"><span>Short range forecasting of sea breeze generated thunderstorms at the Kennedy Space Center: A real-time experiment using a primitive equation <span class="hlt">mesoscale</span> numerical <span class="hlt">model</span></span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Lyons, Walter A.; Schuh, Jerome A.; Moon, Dennis; Pielke, Roger A.; Cotton, William; Arritt, Raymond</p> <p>1987-01-01</p> <p>The operational efficiency of using guidance from a <span class="hlt">mesoscale</span> numerical <span class="hlt">model</span> to improve sea breeze thunderstorm forecasts at and around the Shuttle landing strip was assessed. The Prognostic Three-Dimensional <span class="hlt">Mesoscale</span> (P3DM) <span class="hlt">model</span>, developed as a sea breeze <span class="hlt">model</span>, reveals a strong correlation between regions of <span class="hlt">mesoscale</span> convergence and the triggering of sea breeze convection thunderstorms. The P3DM was modified to generate stability parameters familiar to the operational forecaster. In addition to the <span class="hlt">mesoscale</span> fields of wind, vertical motion, moisture, temperature, a stability indicator, a combination of <span class="hlt">model</span>-predicted K and Lifted Indices and the maximum grid cell vertical motion, were proposed and tested. Results of blind tests indicate that a forecaster, provided with guidance derived from <span class="hlt">model</span> output, could improve local thunderstorm forecasts.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/scitech/biblio/22230857','SCIGOV-STC'); return false;" href="https://www.osti.gov/scitech/biblio/22230857"><span>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/1993PhDT.......307S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/1993PhDT.......307S"><span>A Investigation of Colorado Front Range Winter Storms Using a Nonhydrostatic <span class="hlt">Mesoscale</span> Numerical <span class="hlt">Model</span> Designed for Operational Use</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Snook, John Stover</p> <p></p> <p>State-of-the-art data sources such as Doppler radar, automated surface observations, wind profiler, digital satellite, and aircraft reports are for the first time providing the capability to generate real-time, operational three-dimensional gridded data sets with sufficient spatial and temporal resolutions to diagnose the structure and evolution of <span class="hlt">mesoscale</span> systems. A prototype data assimilation system of this type, called the Local Analysis and Prediction System (LAPS), is being developed at the National Oceanic and Atmospheric System's Forecast Systems Laboratory (FSL). The investigation utilizes the three-dimensional LAPS analyses for initialization of the full physics, nonhydrostatic Regional Atmospheric <span class="hlt">Modeling</span> System (RAMS) <span class="hlt">model</span> developed at the Colorado State University to create a system capable of generating operational <span class="hlt">mesoscale</span> predictions. The LAPS/RAMS system structured for operational use can add significant value to existing operational <span class="hlt">model</span> output and can provide an improved scientific understanding of <span class="hlt">mesoscale</span> weather events. The results are presented through two case study analyses, the 7 January 1992 Colorado Front Range blizzard and the 8-9 March 1992 eastern Colorado snow storm. Both cases are ideal for this investigation due to the significant <span class="hlt">mesoscale</span> variation observed in the precipitation and flow structure. The case study results demonstrate the ability to successfully detect and predict <span class="hlt">mesoscale</span> features using a <span class="hlt">mesoscale</span> numerical <span class="hlt">model</span> initialized with high resolution (10 km horizontal grid interval), non-homogeneous data. The strong influence of the Colorado topography on the resultant flow is suggested by the generation of a lee vortex that frequently develops east of the Front Range and south of the Cheyenne Ridge in stable, northwest synoptic flow. The lee vortex exhibits surface flow characteristics that are similar to results from low Froude number flow around an isolated obstacle. A series of numerical experiments using</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><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://adsabs.harvard.edu/abs/2016AGUFM.H33H1664D','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016AGUFM.H33H1664D"><span>Integrating satellite actual evapotranspiration patterns into distributed <span class="hlt">model</span> parametrization and evaluation for a <span class="hlt">mesoscale</span> catchment</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Demirel, M. C.; Mai, J.; Stisen, S.; Mendiguren González, G.; Koch, J.; Samaniego, L. E.</p> <p>2016-12-01</p> <p>Distributed hydrologic <span class="hlt">models</span> are traditionally calibrated and evaluated against observations of streamflow. Spatially distributed remote sensing observations offer a great opportunity to enhance spatial <span class="hlt">model</span> calibration schemes. For that it is important to identify the <span class="hlt">model</span> parameters that can change spatial patterns before the satellite based hydrologic <span class="hlt">model</span> calibration. Our study is based on two main pillars: first we use spatial sensitivity analysis to identify the key parameters controlling the spatial distribution of actual evapotranspiration (AET). Second, we investigate the potential benefits of incorporating spatial patterns from MODIS data to calibrate the <span class="hlt">mesoscale</span> Hydrologic <span class="hlt">Model</span> (mHM). This distributed <span class="hlt">model</span> is selected as it allows for a change in the spatial distribution of key soil parameters through the calibration of pedo-transfer function parameters and includes options for using fully distributed daily Leaf Area Index (LAI) directly as input. In addition the simulated AET can be estimated at the spatial resolution suitable for comparison to the spatial patterns observed using MODIS data. We introduce a new dynamic scaling function employing remotely sensed vegetation to downscale coarse reference evapotranspiration. In total, 17 parameters of 47 mHM parameters are identified using both sequential screening and Latin hypercube one-at-a-time sampling methods. The spatial patterns are found to be sensitive to the vegetation parameters whereas streamflow dynamics are sensitive to the PTF parameters. The results of multi-objective <span class="hlt">model</span> calibration show that calibration of mHM against observed streamflow does not reduce the spatial errors in AET while they improve only the streamflow simulations. We will further examine the results of <span class="hlt">model</span> calibration using only multi spatial objective functions measuring the association between observed AET and simulated AET maps and another case including spatial and streamflow metrics together.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/pages/biblio/1287335-atomistically-informed-mesoscale-model-growth-coarsening-during-discharge-lithium-oxygen-batteries','SCIGOV-DOEP'); return false;" href="https://www.osti.gov/pages/biblio/1287335-atomistically-informed-mesoscale-model-growth-coarsening-during-discharge-lithium-oxygen-batteries"><span>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/pages">DOE PAGES</a></p> <p>Welland, Michael J.; Lau, Kah Chun; Redfern, Paul C.; ...</p> <p>2015-12-10</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,more » 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. Finally, 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.« less</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/servlets/purl/1287335','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/servlets/purl/1287335"><span>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>2015-12-10</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</sub> 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</sub> formation through reaction of O<sub>2</sub><sup>-</sup> and Li<sup>+</sup> in the electrolyte, which deposits on the cathode surface when the LiO<sub>2</sub> 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</sub> 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</sub> 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. Finally, 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</sub>O<sub>2</sub> deposition, in Li-O<sub>2</sub> batteries and nucleation and growth in Li-S batteries.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/scitech/biblio/22493306','SCIGOV-STC'); return false;" href="https://www.osti.gov/scitech/biblio/22493306"><span>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('https://www.ncbi.nlm.nih.gov/pubmed/26671364','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/26671364"><span>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.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/scitech/biblio/1287335','SCIGOV-STC'); return false;" href="https://www.osti.gov/scitech/biblio/1287335"><span>An atomistically informed <span class="hlt">mesoscale</span> <span class="hlt">model</span> for growth and coarsening during discharge in lithium-oxygen batteries</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Welland, Michael J.; Lau, Kah Chun; Redfern, Paul C.; Liang, Linyun; Zhai, Denyun; Wolf, Dieter; Curtiss, Larry A.</p> <p>2015-12-14</p> <p>An atomistically informed <span class="hlt">mesoscale</span> <span class="hlt">model</span> is developed for the deposition of a discharge product in a Li-O-2 battery. This mescocale <span class="hlt">model</span> includes particle growth and coarsening as well as a simplified nucleation <span class="hlt">model</span>. The <span class="hlt">model</span> involves LiO2 formation through reaction of O-2(-) and Li+ in the electrolyte, which deposits on the cathode surface when the LiO2 concentration reaches supersaturation in the electrolyte. A reaction-diffusion (rate-equation) <span class="hlt">model</span> is used to describe the processes occurring in the electrolyte and a phase-field <span class="hlt">model</span> is used to capture microstructural evolution. This <span class="hlt">model</span> predicts that coarsening, in which large particles grow and small ones disappear, has a substantial effect on the size distribution of the LiO2 particles during the discharge process. The size evolution during discharge is the result of the interplay between this coarsening process and particle growth. The growth through continued deposition of LiO2 has the effect of causing large particles to grow ever faster while delaying the dissolution of small particles. The predicted size evolution is consistent with experimental results for a previously reported cathode material based on activated carbon during discharge and when it is at rest, although kinetic factors need to be included. The approach described in this paper synergistically combines <span class="hlt">models</span> on different length scales with experimental observations and should have applications in studying other related discharge processes, such as Li2O2 deposition, in Li-O-2 batteries and nucleation and growth in Li-S batteries.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.dtic.mil/docs/citations/ADA631433','DTIC-ST'); return false;" href="http://www.dtic.mil/docs/citations/ADA631433"><span>A Rapidly Relocatable, Coupled <span class="hlt">Mesoscale</span> <span class="hlt">Modeling</span> System for Naval Special Warfare</span></a></p> <p><a target="_blank" href="http://www.dtic.mil/">DTIC Science & Technology</a></p> <p></p> <p>2016-06-13</p> <p>LINUX cluster (part of this project) and transitioned to the Navy through the Centralized Atmospheric Analysis and Prediction System (CAAPS) at FNMOC...an ocean <span class="hlt">model</span>. WORK COMPLETED A 20-node LINUX cluster was installed at NRL-Monterey on August 15, 2005. The COAMPS-OS V1.2 was loaded onto...the cluster with MVOI and the Navy Coupled Ocean Data Assimilation (NCODA). COAMPS consisting of a total of 4 <span class="hlt">nests</span> (45/15/5/1.67 km) has been running</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2003PApGe.160..429R','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2003PApGe.160..429R"><span>Three-dimensional Simulations of the Mean Air Transport During the 1997 Forest Fires in Kalimantan, Indonesia Using a <span class="hlt">Mesoscale</span> Numerical <span class="hlt">Model</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Roswintiarti, O.; Raman, S.</p> <p></p> <p>- This paper describes the meteorological processes responsible for the mean transport of air pollutants during the ENSO-related forest fires in Kalimantan, Indonesia from 00 UTC 21 September to 00 UTC 25 September, 1997. The Fifth Generation of the Pennsylvania State University-National Center for Atmospheric Research (PSU-NCAR) <span class="hlt">Mesoscale</span> <span class="hlt">Model</span> (MM5) is used to simulate three-dimensional winds at 6-hourly intervals. A nonhydrostatic version of the <span class="hlt">model</span> is run using two <span class="hlt">nested</span> grids with horizontal resolutions of 45 km and 15 km. From the simulated wind fields, the backward and forward trajectories of the air parcel are investigated using the Vis5D <span class="hlt">model</span>.The results indicate that the large-scale subsidence over Indonesia, the southwest monsoon low-level flows (2-8 m s-1), and the shallow planetary boundary layer height (400-800 m) play a key role in the transport of air pollutants from Kalimantan to Malaysia, Singapore and Brunei.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/19990109664','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19990109664"><span>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> </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('https://www.osti.gov/scitech/biblio/1257067','SCIGOV-STC'); return false;" href="https://www.osti.gov/scitech/biblio/1257067"><span>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('https://www.osti.gov/scitech/biblio/5487152','SCIGOV-STC'); return false;" href="https://www.osti.gov/scitech/biblio/5487152"><span><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://adsabs.harvard.edu/abs/2015SPIE.9614E..0KH','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015SPIE.9614E..0KH"><span><span class="hlt">Mesoscale</span> <span class="hlt">modeling</span> of optical turbulence (C2n) utilizing a novel physically-based parameterization</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>He, Ping; Basu, Sukanta</p> <p>2015-09-01</p> <p>In this paper, we propose a novel parameterization for optical turbulence (C2n) simulations in the atmosphere. In this approach, C2n is calculated from the output of atmospheric <span class="hlt">models</span> using a high-order turbulence closure scheme. An important feature of this parameterization is that, in the free atmosphere (i.e., above the boundary layer), it is consistent with a well-established C2n formulation by Tatarskii. Furthermore, it approaches a Monin-Obukhov similarity-based relationship in the surface layer. To test the performance of the proposed parameterization, we conduct <span class="hlt">mesoscale</span> <span class="hlt">modeling</span> and compare the simulated C2n values with those measured during two field campaigns over the Hawaii island. A popular regression-based approach proposed by Trinquet and Vernin (2007) is also used for comparison. The predicted C2n values, obtained from both the physically and statistically-based parameterizations, agree reasonably well with the observational data. However, in the presence of a large-scale atmospheric phenomenon (a breaking mountain wave), the physically-based parameterization outperforms the statistically-based one.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2010HESSD...7.5299E','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2010HESSD...7.5299E"><span>Ensemble <span class="hlt">modelling</span> of nitrogen fluxes: data fusion for a Swedish <span class="hlt">meso-scale</span> catchment</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Exbrayat, J.-F.; Viney, N. R.; Seibert, J.; Wrede, S.; Frede, H.-G.; Breuer, L.</p> <p>2010-08-01</p> <p><span class="hlt">Model</span> predictions of biogeochemical fluxes at the landscape scale are highly uncertain, both with respect to stochastic (parameter) and structural uncertainty. In this study 5 different <span class="hlt">models</span> (LASCAM, LASCAM-S, a self-developed tool, SWAT and HBV-N-D) designed to simulate hydrological fluxes as well as mobilisation and transport of one or several nitrogen species were applied to the <span class="hlt">mesoscale</span> River Fyris catchment in mid-eastern Sweden. Hydrological calibration against 5 years of recorded daily discharge at two stations gave highly variable results with Nash-Sutcliffe Efficiency (NSE) ranging between 0.48 and 0.83. Using the calibrated hydrological parameter sets, the parameter uncertainty linked to the nitrogen parameters was explored in order to cover the range of possible predictions of exported loads for 3 nitrogen species: nitrate (NO3), ammonium (NH4) and total nitrogen (Tot-N). For each <span class="hlt">model</span> and each nitrogen species, predictions were ranked in two different ways according to the performance indicated by two different goodness-of-fit measures: the coefficient of determination R2 and the root mean square error RMSE. A total of 2160 deterministic Single <span class="hlt">Model</span> Ensembles (SME) was generated using an increasing number of members (from the 2 best to the 10 best single predictions). Finally, the best SME for each <span class="hlt">model</span>, nitrogen species and discharge station were selected and merged into 330 different Multi-<span class="hlt">Model</span> Ensembles (MME). The evolution of changes in R2 and RMSE was used as a performance descriptor of the ensemble procedure. In each studied case, numerous ensemble merging schemes were identified which outperformed any of their members. Improvement rates were generally higher when worse members were introduced. The highest improvements were achieved for the nitrogen SMEs compiled with multiple linear regression <span class="hlt">models</span> with R2 selected members, which resulted in the RMSE decreasing by up to 90%.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2010HESS...14.2383E','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2010HESS...14.2383E"><span>Ensemble <span class="hlt">modelling</span> of nitrogen fluxes: data fusion for a Swedish <span class="hlt">meso-scale</span> catchment</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Exbrayat, J.-F.; Viney, N. R.; Seibert, J.; Wrede, S.; Frede, H.-G.; Breuer, L.</p> <p>2010-12-01</p> <p><span class="hlt">Model</span> predictions of biogeochemical fluxes at the landscape scale are highly uncertain, both with respect to stochastic (parameter) and structural uncertainty. In this study 5 different <span class="hlt">models</span> (LASCAM, LASCAM-S, a self-developed tool, SWAT and HBV-N-D) designed to simulate hydrological fluxes as well as mobilisation and transport of one or several nitrogen species were applied to the <span class="hlt">mesoscale</span> River Fyris catchment in mid-eastern Sweden. Hydrological calibration against 5 years of recorded daily discharge at two stations gave highly variable results with Nash-Sutcliffe Efficiency (NSE) ranging between 0.48 and 0.83. Using the calibrated hydrological parameter sets, the parameter uncertainty linked to the nitrogen parameters was explored in order to cover the range of possible predictions of exported loads for 3 nitrogen species: nitrate (NO3), ammonium (NH4) and total nitrogen (Tot-N). For each <span class="hlt">model</span> and each nitrogen species, predictions were ranked in two different ways according to the performance indicated by two different goodness-of-fit measures: the coefficient of determination R2 and the root mean square error RMSE. A total of 2160 deterministic Single <span class="hlt">Model</span> Ensembles (SME) was generated using an increasing number of members (from the 2 best to the 10 best single predictions). Finally the best SME for each <span class="hlt">model</span>, nitrogen species and discharge station were selected and merged into 330 different Multi-<span class="hlt">Model</span> Ensembles (MME). The evolution of changes in R2 and RMSE was used as a performance descriptor of the ensemble procedure. In each studied case, numerous ensemble merging schemes were identified which outperformed any of their members. Improvement rates were generally higher when worse members were introduced. The highest improvements were achieved for the nitrogen SMEs compiled with multiple linear regression <span class="hlt">models</span> with R2 selected members, which resulted in the RMSE decreasing by up to 90%.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017JAMES...9..790T','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017JAMES...9..790T"><span>The impact of simulated <span class="hlt">mesoscale</span> convective systems on global precipitation: A multiscale <span class="hlt">modeling</span> study</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Tao, Wei-Kuo; Chern, Jiun-Dar</p> <p>2017-06-01</p> <p>The importance of precipitating <span class="hlt">mesoscale</span> convective systems (MCSs) has been quantified from TRMM precipitation radar and microwave imager retrievals. MCSs generate more than 50% of the rainfall in most tropical regions. MCSs usually have horizontal scales of a few hundred kilometers (km); therefore, a large domain with several hundred km is required for realistic simulations of MCSs in cloud-resolving <span class="hlt">models</span> (CRMs). Almost all traditional global and climate <span class="hlt">models</span> do not have adequate parameterizations to represent MCSs. Typical multiscale <span class="hlt">modeling</span> frameworks (MMFs) may also lack the resolution (4 km grid spacing) and domain size (128 km) to realistically simulate MCSs. The impact of MCSs on precipitation is examined by conducting <span class="hlt">model</span> simulations using the Goddard Cumulus Ensemble (GCE, a CRM) <span class="hlt">model</span> and Goddard MMF that uses the GCEs as its embedded CRMs. Both <span class="hlt">models</span> can realistically simulate MCSs with more grid points (i.e., 128 and 256) and higher resolutions (1 or 2 km) compared to those simulations with fewer grid points (i.e., 32 and 64) and low resolution (4 km). The <span class="hlt">modeling</span> results also show the strengths of the Hadley circulations, mean zonal and regional vertical velocities, surface evaporation, and amount of surface rainfall are weaker or reduced in the Goddard MMF when using more CRM grid points and higher CRM resolution. In addition, the results indicate that large-scale surface evaporation and wind feedback are key processes for determining the surface rainfall amount in the GMMF. A sensitivity test with reduced sea surface temperatures shows both reduced surface rainfall and evaporation.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017EGUGA..19.2865T','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017EGUGA..19.2865T"><span>The impact of <span class="hlt">mesoscale</span> convective systems on global precipitation: A <span class="hlt">modeling</span> study</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Tao, Wei-Kuo</p> <p>2017-04-01</p> <p>The importance of precipitating <span class="hlt">mesoscale</span> convective systems (MCSs) has been quantified from TRMM precipitation radar and microwave imager retrievals. MCSs generate more than 50% of the rainfall in most tropical regions. Typical MCSs have horizontal scales of a few hundred kilometers (km); therefore, a large domain and high resolution are required for realistic simulations of MCSs in cloud-resolving <span class="hlt">models</span> (CRMs). Almost all traditional global and climate <span class="hlt">models</span> do not have adequate parameterizations to represent MCSs. Typical multi-scale <span class="hlt">modeling</span> frameworks (MMFs) with 32 CRM grid points and 4 km grid spacing also might not have sufficient resolution and domain size for realistically simulating MCSs. In this study, the impact of MCSs on precipitation processes is examined by conducting numerical <span class="hlt">model</span> simulations using the Goddard Cumulus Ensemble <span class="hlt">model</span> (GCE) and Goddard MMF (GMMF). The results indicate that both <span class="hlt">models</span> can realistically simulate MCSs with more grid points (i.e., 128 and 256) and higher resolutions (1 or 2 km) compared to those simulations with less grid points (i.e., 32 and 64) and low resolution (4 km). The <span class="hlt">modeling</span> results also show that the strengths of the Hadley circulations, mean zonal and regional vertical velocities, surface evaporation, and amount of surface rainfall are either weaker or reduced in the GMMF when using more CRM grid points and higher CRM resolution. In addition, the results indicate that large-scale surface evaporation and wind feed back are key processes for determining the surface rainfall amount in the GMMF. A sensitivity test with reduced sea surface temperatures (SSTs) is conducted and results in both reduced surface rainfall and evaporation.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016AGUFM.H43H1557S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016AGUFM.H43H1557S"><span>Assessment of A <span class="hlt">Mesoscale</span> Numerical Weather Prediction <span class="hlt">Model</span> Parameterization for Flood Forecasting in the Indian Subcontinent</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Sikder, M. S.; Hossain, F.</p> <p>2016-12-01</p> <p>The Indian subcontinent comprises a few of the world's most populated international river basins such as the Ganges, Brahmaputra, Indus. These river basins are located within the monsoon climate regime. Early flood forecasting is vital to this region, where over 900 million people are directly or indirectly affected by the annual monsoon flooding. Using the <span class="hlt">model</span> simulated hydro-meteorological data in the flood forecasting system is one of the most effective ways to forecast floods in this region, as the real-time observed data are unavailable due to hydro-political issue. It is therefore appropriate to assess a <span class="hlt">mesoscale</span> Numerical Weather Prediction (NWP) <span class="hlt">model</span> to find out a common set of suitable <span class="hlt">model</span> parameterization schemes to assist the flood forecasting systems of this region. In this study, we used the Weather Research and Forecasting (WRF) <span class="hlt">model</span> to estimate precipitation of the Ganges-Brahmaputra for peak one month of the 2015 monsoon using 30 different combinations. Combinations of five cloud microphysics, three cumulus parameterization schemes, and two spatial resolutions were used in this step to detect the best schemes for the Ganges-Brahmaputra. Finally, we applied the selected best combinations in the Indus basin to simulate the 2010 extreme event and found a similar <span class="hlt">model</span> response as the Ganges-Brahmaputra basin. Our results identified a common set of suitable <span class="hlt">model</span> parameterization schemes, which performs well all over the Indian subcontinent. The basin discharge can also be estimated using a pre-calibrated hydrological <span class="hlt">model</span> based on the best set of forcing data from the WRF outputs.</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=91066974&CFTOKEN=38372087','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=91066974&CFTOKEN=38372087"><span>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=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','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"><span>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=bird&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','EPA-EIMS'); return false;" href="http://cfpub.epa.gov/si/si_public_record_report.cfm?dirEntryId=257882&keyword=bird&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"><span>User’s manual for basic version of MCnest Markov chain <span class="hlt">nest</span> productivity <span class="hlt">model</span></span></a></p> <p><a target="_blank" href="http://oaspub.epa.gov/eims/query.page">EPA Science Inventory</a></p> <p></p> <p></p> <p>The Markov Chain <span class="hlt">Nest</span> Productivity <span class="hlt">Model</span> (or MCnest) integrates existing toxicity information from three standardized avian toxicity tests with information on species life history and the timing of pesticide applications relative to the timing of avian breeding seasons to quantit...</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://cfpub.epa.gov/si/si_public_record_report.cfm?dirEntryId=257882&keyword=bird&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=78733660&CFTOKEN=51069820','EPA-EIMS'); return false;" href="http://cfpub.epa.gov/si/si_public_record_report.cfm?dirEntryId=257882&keyword=bird&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=78733660&CFTOKEN=51069820"><span>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('https://www.ncbi.nlm.nih.gov/pubmed/26712602','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/26712602"><span>A <span class="hlt">meso-scale</span> layer-specific structural constitutive <span class="hlt">model</span> of the mitral heart valve leaflets.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Zhang, Will; Ayoub, Salma; Liao, Jun; Sacks, Michael S</p> <p>2016-03-01</p> <p>Fundamental to developing a deeper understanding of pathophysiological remodeling in mitral valve (MV) disease is the development of an accurate tissue-level constitutive <span class="hlt">model</span>. In the present work, we developed a novel <span class="hlt">meso-scale</span> (i.e. at the level of the fiber, 10-100 μm in length scale) structural constitutive <span class="hlt">model</span> (MSSCM) for MV leaflet tissues. Due to its four-layer structure, we focused on the contributions from the distinct collagen and elastin fiber networks within each tissue layer. Requisite collagen and elastin fibrous structural information for each layer were quantified using second harmonic generation microscopy and conventional histology. A comprehensive mechanical dataset was also used to guide <span class="hlt">model</span> formulation and parameter estimation. Furthermore, novel to tissue-level structural constitutive <span class="hlt">modeling</span> approaches, we allowed the collagen fiber recruitment function to vary with orientation. Results indicated that the MSSCM predicted a surprisingly consistent mean effective collagen fiber modulus of 162.72 MPa, and demonstrated excellent predictive capability for extra-physiological loading regimes. There were also anterior-posterior leaflet-specific differences, such as tighter collagen and elastin fiber orientation distributions (ODF) in the anterior leaflet, and a thicker and stiffer atrialis in the posterior leaflet. While a degree of angular variance was observed, the tight valvular tissue ODF also left little room for any physically meaningful angular variance in fiber mechanical responses. Finally, a novel fibril-level (0.1-1 μm) validation approach was used to compare the predicted collagen fiber/fibril mechanical behavior with extant MV small angle X-ray scattering data. Results demonstrated excellent agreement, indicating that the MSSCM fully captures the tissue-level function. Future utilization of the MSSCM in computational <span class="hlt">models</span> of the MV will aid in producing highly accurate simulations in non-physiological loading states that can</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015OcScD..12..493L','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015OcScD..12..493L"><span><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>2015-03-01</p> <p>The Arabian Sea and Sea of Oman circulation and water masses, subject to the monsoon forcing, reveal a strong seasonal variability and intense <span class="hlt">mesoscale</span> features. We describe and analyse this variability and these features, using both meteorological data (from ECMWF reanalyses), in-situ observations (from the ARGO float program and the GDEM climatology), satellite altimetry (from AVISO) and a regional simulation with a primitive equation <span class="hlt">model</span> (HYCOM). The EOFs of the seasonal variability of the water masses quantify their main changes in thermohaline characteristics and in position. The <span class="hlt">model</span> and observations display comparable variability, and the <span class="hlt">model</span> is then used to analyse the three-dimensional structure of eddies and water masses with a higher resolution. 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. This water mass is also captured inside the eddies via several mechanisms, keeping high thermohaline characteristics in the Arabian Sea. These characteristics are validated on the GOGP99 cruise data.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://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="https://ntrs.nasa.gov/search.jsp?R=20030054358&hterms=meteorology&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D70%26Ntt%3Dmeteorology"><span>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/2010EGUGA..12.9022Z','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2010EGUGA..12.9022Z"><span>A new raytracing algorithm to compute slant total delays in 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>Zus, Florian; Bender, Michael; Dick, Galina; Deng, Zhiguo; Heise, Stefan; Wickert, Jens</p> <p>2010-05-01</p> <p>Ray-tracing is essential to accurately simulate Global Positioning System (GPS) Slant Total Delays (STD) in a <span class="hlt">mesoscale</span> atmospheric <span class="hlt">model</span>. A rigorous ray-tracing algorithm based on Fermat's principle was developed to simulate the propagation of radio signals in a gridded 3D refractivity field. The unique in the proposed algorithm is that the solution automatically involves the exact location of the receiver and the satellite, i.e. 'shooting' is not required. The structured non-linear system of equations, arising due to the applied finite difference scheme, is solved by Newton's iteration. For elevation angles as low as 5 degree at a ground-based receiver a single Newton iteration turns out to be sufficient. Subsequently the algorithm allows us to simulate about 1500 STDs per second on a single CPU. Having developed the forward operator for STDs, we constructed the tangent linear and adjoint code for sensitivity and variational data analysis. First results from three potential applications of the proposed ray-tracing algorithm are presented: (1) monitoring STD data processed at the GFZ Potsdam against European Centre for Medium-Range Weather Forecasts (ECMWF) analysis, (2) vertical profiling, i.e. the retrieval of the refractivity profile above a ground based receiver from the STD data by using a least square adjustment, and (3) direct mapping.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/26602508','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/26602508"><span>Electrostatic Interactions in Dissipative Particle Dynamics: Toward a <span class="hlt">Mesoscale</span> <span class="hlt">Modeling</span> of the Polyelectrolyte Brushes.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Ibergay, Cyrille; Malfreyt, Patrice; Tildesley, Dominic J</p> <p>2009-12-08</p> <p>We report mesoscopic simulations of bulk electrolytes and polyelectrolyte brushes using the dissipative particle dynamics (DPD) method. The calculation of the electrostatic interactions is carried out using both the Ewald summation method and the particle-particle particle-mesh technique with charges distributed over the particles. The local components of the pressure tensor are calculated using the Irving and Kirkwood, and the method of planes and mechanical equilibrium is demonstrated. The profiles of the normal component of the pressure tensor are shown to be similar for both the Ewald and particle-particle particle-mesh methods for a single polyelectrolyte brush. We show that the PPPM method with the MOP technique is the appropriate choice for simulations of this type. The <span class="hlt">mesoscale</span> <span class="hlt">modeling</span> of a strongly stretched polylectrolyte brush formed by strong charged polymer chains at a high grafting density shows that the polyelectrolyte follows the nonlinear osmotic regime, as expected from the calculation of the Gouy-Chapman length and the dimensionless Manning ratio.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017PhRvB..96a4405T','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017PhRvB..96a4405T"><span>Dynamic <span class="hlt">mesoscale</span> <span class="hlt">model</span> of the metamagnetic transition in low-bandwidth perovskite manganites</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Tikkanen, J.; Huhtinen, H.; Paturi, P.</p> <p>2017-07-01</p> <p>Using bulk magnetometry, it was experimentally verified that the metamagnetic insulator-to-metal transition observed in the perovskite manganite Pr1 -xCaxMnO3 (PCMO) occurs at different critical values of the magnetic-field strength, depending on the macroscopic geometry of the sample in the absence of applied elastic strain. In dimensionally confined samples, such as nanoparticles and thin films, the critical magnetic field can be lower than in bulk by several teslas. To gain a practical understanding of the mechanism behind this correlation, a phenomenological <span class="hlt">mesoscale</span> simulation was developed to <span class="hlt">model</span> and analyze the magnetic hysteresis of PCMO. It could be concluded that the low-dimensional samples have a well-defined, permanent free energy bias towards ferromagnetism, something the largely antiferromagnetic bulk all but lacks. The metamagnetic transition field of PCMO turns out to be globally minimized when no external elastic strain is applied and the smallest spatial dimension of the sample approaches 100 nm. The result is likely to apply equally to other low-bandwidth manganites.</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>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('https://ntrs.nasa.gov/search.jsp?R=20010021327&hterms=Data+Base+Technique&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D50%26Ntt%3DData%2BBase%2BTechnique','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=20010021327&hterms=Data+Base+Technique&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D50%26Ntt%3DData%2BBase%2BTechnique"><span>Use of Geostationary Satellite Data to Force Land Surface Schemes within Atmospheric <span class="hlt">Mesoscale</span> <span class="hlt">Models</span></span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Lapenta, William M.; Suggs, Ron; McNider, Richard T.; Jedlovec, Gary; Dembek, Scott R.; Goodman, H. Michael (Technical Monitor)</p> <p>2000-01-01</p> <p>A technique has been developed for assimilating GOES-derived skin temperature tendencies and insolation into the surface energy budget equation of a <span class="hlt">mesoscale</span> <span class="hlt">model</span> so that the simulated rate of temperature change closely agrees with the satellite observations. A critical assumption of the technique is that the availability of moisture (either from the soil or vegetation) is the least known term in the <span class="hlt">model</span>'s surface energy budget. Therefore, the simulated latent heat flux, which is a function of surface moisture availability, is adjusted based upon differences between the <span class="hlt">modeled</span> and satellite-observed skin temperature tendencies. An advantage of this technique is that satellite temperature tendencies are assimilated in an energetically consistent manner that avoids energy imbalances and surface stability problems that arise from direct assimilation of surface shelter temperatures. The fact that the rate of change of the satellite skin temperature is used rather than the absolute temperature means that sensor calibration is not as critical. The technique has been employed on a semi-operational basis at the GHCC within the PSU/NCAR MM5. Assimilation has been performed on a grid centered over the Southeastern US since November 1998. Results from the past year show that assimilation of the satellite data reduces both the bias and RMSE for simulations of surface air temperature and relative humidity. These findings are based on comparison of assimilation runs with a control using the simple 5-layer soil <span class="hlt">model</span> available in MM5. A significant development in the past several months was the inclusion of the detailed Oregon State University land surface <span class="hlt">model</span> (OSU/LSM) as an option within MM5. One of our working hypotheses has been that the assimilation technique, although simple, may provide better short-term forecasts than a detailed LSM that requires significant number initialized parameters. Preliminary results indicate that the assimilation out performs the OSU</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_16");'>16</a></li> <li><a href="#" onclick='return showDiv("page_17");'>17</a></li> <li class="active"><span>18</span></li> <li><a href="#" onclick='return showDiv("page_19");'>19</a></li> <li><a href="#" onclick='return showDiv("page_20");'>20</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_18 --> <div id="page_19" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_17");'>17</a></li> <li><a href="#" onclick='return showDiv("page_18");'>18</a></li> <li class="active"><span>19</span></li> <li><a href="#" onclick='return showDiv("page_20");'>20</a></li> <li><a href="#" onclick='return showDiv("page_21");'>21</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="361"> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2011Geomo.130..230D','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2011Geomo.130..230D"><span><span class="hlt">Meso-scale</span> <span class="hlt">modelling</span> of aeolian sediment input to coastal dunes</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Delgado-Fernandez, Irene</p> <p>2011-07-01</p> <p>The collection of a time series coupling hourly wind data (speed and direction) with sand transport over months has provided new insights into the dynamics of transport events that input sediment to the foredune at Greenwich Dunes, Prince Edward Island National Park, Canada. This paper summarises the key aspects of aeolian sediment movement for a period of 9 months and presents a <span class="hlt">modelling</span> approach for resolving aeolian transport to coastal dunes at the <span class="hlt">meso-scale</span>. The main hypothesis of the <span class="hlt">modelling</span> approach is that a small number of key factors control both the occurrence and the magnitude of transport events. Thresholds associated with these factors may be used to filter the time series and isolate potential transport periods over the year. The impacts of nearshore processes are included in the approach as part of the dynamics of coastal dunes, as are supply-limiting factors and trade-offs between fetch distances, angle of wind approach, and beach dimensions. A simple analytical procedure, based on previously published equations, is carried out to assess the general viability of the conceptual approach. Results show that the incorporation of moisture and fetch effects in the calculation of transport for isolated potential transport periods result in improved predictions of sediment input to the dune. Net changes, measured with three different techniques, suggest that survey data with coarse temporal resolution underestimates the amount of sand input to the dune, because sediment is often removed from the embryo dune and foredune by other processes such as wave scarping. Predictions obtained by the proposed <span class="hlt">modelling</span> approach are of the same order of magnitude as measured deposition and much less than predicted by <span class="hlt">models</span> based solely on wind speed and direction. Areas for improvement and alternative <span class="hlt">modelling</span> approaches, such as probabilistic approaches similar to weather forecasting, are covered in the discussion.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=20040016359&hterms=Seasons&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D50%26Ntt%3DSeasons','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=20040016359&hterms=Seasons&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D50%26Ntt%3DSeasons"><span>Diabatic Initialization of <span class="hlt">Mesoscale</span> <span class="hlt">Models</span> in the Southeastern United States: Can 0 to 12h Warm Season QPF be Improved?</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Lapenta, William M.; Bradshaw, Tom; Burks, Jason; Darden, Chris; Dembek, Scott</p> <p>2003-01-01</p> <p>It is well known that numerical warm season quantitative precipitation forecasts lack significant skill for numerous reasons. Some are related to the <span class="hlt">model</span>--it may lack physical processes required to realistically simulate convection or the numerical algorithms and dynamics employed may not be adequate. Others are related to initialization-<span class="hlt">mesoscale</span> features play an important role in convective initialization and atmospheric observation systems are incapable of properly depicting the three-dimensional stability structure at the <span class="hlt">mesoscale</span>. The purpose of this study is to determine if a <span class="hlt">mesoscale</span> <span class="hlt">model</span> initialized with a diabatic initialization scheme can improve short-term (0 to 12h) warm season quantitative precipitation forecasts in the Southeastern United States. The Local Analysis and Prediction System (LAPS) developed at the Forecast System Laboratory is used to diabatically initialize the Pennsylvania State University/National center for Atmospheric Research (PSUNCAR) <span class="hlt">Mesoscale</span> <span class="hlt">Model</span> version 5 (MM5). The SPORT Center runs LAPS operationally on an hourly cycle to produce analyses on a 15 km covering the eastern 2/3 of the United States. The 20 km National Centers for Environmental Prediction (NCEP) Rapid Update Cycle analyses are used for the background fields. Standard observational data are acquired from MADIS with GOES/CRAFT Nexrad data acquired from in-house feeds. The MM5 is configured on a 140 x 140 12 km grid centered on Huntsville Alabama. Preliminary results indicate that MM5 runs initialized with LAPS produce improved 6 and 12h QPF threat scores compared with those initialized with the NCEP RUC.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2013PhDT........29Y','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2013PhDT........29Y"><span>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://adsabs.harvard.edu/abs/2017EGUGA..1913143W','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017EGUGA..1913143W"><span><span class="hlt">Nested</span> high resolution <span class="hlt">models</span> for the coastal areas of the North Indian Ocean</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Wobus, Fred; Shapiro, Georgy</p> <p>2017-04-01</p> <p>Oceanographic processes at coastal scales require much higher horizontal resolution from both ocean <span class="hlt">models</span> and observations as compared to deep water oceanography. Aside from a few exceptions such as land-locked seas, the hydrodynamics of coastal shallow waters is strongly influenced by the tides, which in turn control the mixing, formation of temperature fronts and other phenomena. The numerical <span class="hlt">modelling</span> of the coastal domains requires good knowledge of the lateral boundary conditions. The application of lateral boundary conditions to ocean <span class="hlt">models</span> is a notoriously tricky task, but can only be avoided with global ocean <span class="hlt">models</span>. Smaller scale regional ocean <span class="hlt">models</span> are typically <span class="hlt">nested</span> within global <span class="hlt">models</span>, and even smaller-scale coastal <span class="hlt">models</span> may be <span class="hlt">nested</span> within regional <span class="hlt">models</span>, creating a <span class="hlt">nesting</span> chain. However a direct <span class="hlt">nesting</span> of a very high resolution coastal <span class="hlt">model</span> into a coarse resolution global <span class="hlt">model</span> results in degrading of the accuracy of the outputs due to the large difference between the <span class="hlt">model</span> resolutions. This is why a <span class="hlt">nesting</span> chain has to be applied, so that every increase in resolution is kept within a reasonable minimum (typically by a factor of 3 to 5 at each step). Global <span class="hlt">models</span> are traditionally non-tidal, so at some stage of the <span class="hlt">nesting</span> chain the tides need to be introduced. This is typically done by calculating the tidal constituents from a dedicated tidal <span class="hlt">model</span> (e.g. TPXO) for all boundary points of a <span class="hlt">nested</span> <span class="hlt">model</span>. The tidal elevation at each boundary location can then be calculated from the harmonics at every <span class="hlt">model</span> time step and the added to the parent <span class="hlt">model</span> non-tidal SSH. This combination of harmonics-derived tidal SSH and non-tidal parent <span class="hlt">model</span> SSH is typically applied to the <span class="hlt">nested</span> domain using the Flather condition, together with the baroclinic velocities from the parent <span class="hlt">model</span>. The harmonics-derived SSH cannot be added to an SSH signal that is already tidal, so the parent <span class="hlt">model</span> SSH has to be either detided or taken from a non-tidal <span class="hlt">model</span></p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016OcMod.106..104P','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016OcMod.106..104P"><span>Optimizing dynamic downscaling in one-way <span class="hlt">nesting</span> using a regional ocean <span class="hlt">model</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Pham, Van Sy; Hwang, Jin Hwan; Ku, Hyeyun</p> <p>2016-10-01</p> <p>Dynamical downscaling with <span class="hlt">nested</span> regional oceanographic <span class="hlt">models</span> has been demonstrated to be an effective approach for both operationally forecasted sea weather on regional scales and projections of future climate change and its impact on the ocean. However, when <span class="hlt">nesting</span> procedures are carried out in dynamic downscaling from a larger-scale <span class="hlt">model</span> or set of observations to a smaller scale, errors are unavoidable due to the differences in grid sizes and updating intervals. The present work assesses the impact of errors produced by <span class="hlt">nesting</span> procedures on the downscaled results from Ocean Regional Circulation <span class="hlt">Models</span> (ORCMs). Errors are identified and evaluated based on their sources and characteristics by employing the Big-Brother Experiment (BBE). The BBE uses the same <span class="hlt">model</span> to produce both <span class="hlt">nesting</span> and <span class="hlt">nested</span> simulations; so it addresses those error sources separately (i.e., without combining the contributions of errors from different sources). Here, we focus on discussing errors resulting from the spatial grids' differences, the updating times and the domain sizes. After the BBE was separately run for diverse cases, a Taylor diagram was used to analyze the results and recommend an optimal combination of grid size, updating period and domain sizes. Finally, suggested setups for the downscaling were evaluated by examining the spatial correlations of variables and the relative magnitudes of variances between the <span class="hlt">nested</span> <span class="hlt">model</span> and the original data.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2009EGUGA..11.5855H','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2009EGUGA..11.5855H"><span>Validation of the <span class="hlt">mesoscale</span> <span class="hlt">model</span> MM5 in reproducing the wind variability in Turkey</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Hidalgo, A.; Marchante, M.; Jiménez, P. A.; García-Bustamante, E.; Montávez, J. P.; Gómez-Navarro, J. J.; Rico, M. C.; Jerez, S.; Navarro, J.; González-Rouco, J. F.</p> <p>2009-04-01</p> <p>The numerous studies assessing the evolution of climate and its potential change at the global scale evidence the need of estimating the impact of expected changes at the regional scale. Particularly interesting is the evaluation of the wind energy resource due to its involvement in the the development and sustainability assessment of alternative energies supply. Prior to a climate change impact evaluation the knowledge of the wind field spatial and temporal variability is required. Various techniques can be applied in order to analyze the surface circulations, their main synoptic forcings and their variability along the recent past climate. A dynamical downscaling approach is applied for an evaluation of the wind resource over Turkey. The study leans on the high resolution simulation of the wind field over Turkey and its validation with an observational dataset. The high resolution climate simulation has been performed with the <span class="hlt">mesoscale</span> <span class="hlt">model</span> MM5, driven by the global <span class="hlt">model</span> ERA40 reanalysis products, for a period of ten years at 10 km of horizontal resolution. In order to analyze the reliability of the simulations, an observational dataset of quality that spans the period from 1978 to 2008 and overlaps the simulation period has been prepared. Observations reveal the presence of a strong annual cycle for the wind field in the region, with maxima wind speeds and prevailing northern circulations appearing in Summer and minima wind speed and a larger variability of the wind direction in Winter. The evaluation of the <span class="hlt">model</span> results, based on the assessement of the distribution concordance and temporal agreement between simulations and surface observations, revealed that the <span class="hlt">model</span> reproduces the regional variability with a systematic wind speed overestimation and evidences accuracy in reproducing the monthly mean wind field and its variability, showing a certain degradation at daily timescales.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://cfpub.epa.gov/si/si_public_record_report.cfm?dirEntryId=234244&keyword=Strategy+AND+technical&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','EPA-EIMS'); return false;" href="http://cfpub.epa.gov/si/si_public_record_report.cfm?dirEntryId=234244&keyword=Strategy+AND+technical&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"><span>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://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=85819782&CFTOKEN=41643043','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=85819782&CFTOKEN=41643043"><span>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://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><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>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('https://ntrs.nasa.gov/search.jsp?R=19820006883&hterms=weather+predictions&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D90%26Ntt%3Dweather%2Bpredictions','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=19820006883&hterms=weather+predictions&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D90%26Ntt%3Dweather%2Bpredictions"><span>The initialization of a <span class="hlt">mesoscale</span> weather prediction <span class="hlt">model</span> using satellite and precipitation data</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Tarbell, T. C.; Warner, T. T.; Wolcott, S. W.</p> <p>1981-01-01</p> <p>An analysis and initialization procedure was developed capable of utilizing <span class="hlt">mesoscale</span> satellite and radar data to resolve features in moisture and momentum fields on a finer scale than is discernible from radiosonde observation networks. The radiosonde moisture field is enhanced, using infrared satellite imagery and precipitation data from the surface observation network (also obtainable from the radar network) while the observed <span class="hlt">mesoscale</span> rainfall rates are also used to define the initial divergent wind component. Results show that the predicted rainfall amounts are significantly improved when these additional data are taken into account.</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>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>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><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/abs/2016OcSci..12.1249L','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016OcSci..12.1249L"><span>GEM: a dynamic tracking <span class="hlt">model</span> for <span class="hlt">mesoscale</span> eddies in the ocean</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Li, Qiu-Yang; Sun, Liang; Lin, Sheng-Fu</p> <p>2016-12-01</p> <p>The Genealogical Evolution <span class="hlt">Model</span> (GEM) presented here is an efficient logical <span class="hlt">model</span> used to track dynamic evolution of <span class="hlt">mesoscale</span> eddies in the ocean. It can distinguish between different dynamic processes (e.g., merging and splitting) within a dynamic evolution pattern, which is difficult to accomplish using other tracking methods. To this end, the GEM first uses a two-dimensional (2-D) similarity vector (i.e., a pair of ratios of overlap area between two eddies to the area of each eddy) rather than a scalar to measure the similarity between eddies, which effectively solves the "missing eddy" problem (temporarily lost eddy in tracking). Second, for tracking when an eddy splits, the GEM uses both "parent" (the original eddy) and "child" (eddy split from parent) and the dynamic processes are described as the birth and death of different generations. Additionally, a new look-ahead approach with selection rules effectively simplifies computation and recording. All of the computational steps are linear and do not include iteration. Given the pixel number of the target region L, the maximum number of eddies M, the number N of look-ahead time steps, and the total number of time steps T, the total computer time is O(LM(N + 1)T). The tracking of each eddy is very smooth because we require that the snapshots of each eddy on adjacent days overlap one another. Although eddy splitting or merging is ubiquitous in the ocean, they have different geographic distributions in the North Pacific Ocean. Both the merging and splitting rates of the eddies are high, especially at the western boundary, in currents and in "eddy deserts". The GEM is useful not only for satellite-based observational data, but also for numerical simulation outputs. It is potentially useful for studying dynamic processes in other related fields, e.g., the dynamics of cyclones in meteorology.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2012AGUFMIN11D1480W','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2012AGUFMIN11D1480W"><span>An Automated Method to Identify <span class="hlt">Mesoscale</span> Convective Complexes in the Regional Climate <span class="hlt">Model</span> Evaluation System</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Whitehall, K. D.; Jenkins, G. S.; Mattmann, C. A.; Waliser, D. E.; Kim, J.; Goodale, C. E.; Hart, A. F.; Ramirez, P.; Whittell, J.; Zimdars, P. A.</p> <p>2012-12-01</p> <p><span class="hlt">Mesoscale</span> convective complexes (MCCs) are large (2 - 3 x 105 km2) nocturnal convectively-driven weather systems that are generally associated with high precipitation events in short durations (less than 12hrs) in various locations through out the tropics and midlatitudes (Maddox 1980). These systems are particularly important for climate in the West Sahel region, where the precipitation associated with them is a principal component of the rainfall season (Laing and Fritsch 1993). These systems occur on weather timescales and are historically identified from weather data analysis via manual and more recently automated processes (Miller and Fritsch 1991, Nesbett 2006, Balmey and Reason 2012). The Regional Climate <span class="hlt">Model</span> Evaluation System (RCMES) is an open source tool designed for easy evaluation of climate and Earth system data through access to standardized datasets, and intrinsic tools that perform common analysis and visualization tasks (Hart et al. 2011). The RCMES toolkit also provides the flexibility of user-defined subroutines for further metrics, visualization and even dataset manipulation. The purpose of this study is to present a methodology for identifying MCCs in observation datasets using the RCMES framework. TRMM 3 hourly datasets will be used to demonstrate the methodology for 2005 boreal summer. This method promotes the use of open source software for scientific data systems to address a concern to multiple stakeholders in the earth sciences. A historical MCC dataset provides a platform with regards to further studies of the variability of frequency on various timescales of MCCs that is important for many including climate scientists, meteorologists, water resource managers, and agriculturalists. The methodology of using RCMES for searching and clipping datasets will engender a new realm of studies as users of the system will no longer be restricted to solely using the datasets as they reside in their own local systems; instead will be afforded rapid</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2010PhDT........82F','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2010PhDT........82F"><span><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>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/2012HESSD...913415D','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2012HESSD...913415D"><span>A flood episode in Northern Italy: multi-<span class="hlt">model</span> and single-<span class="hlt">model</span> <span class="hlt">mesoscale</span> meteorological ensembles for hydrological predictions</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Davolio, S.; Miglietta, M. M.; Diomede, T.; Marsigli, C.; Montani, A.</p> <p>2012-12-01</p> <p>Numerical weather prediction <span class="hlt">models</span> can be coupled with hydrological <span class="hlt">models</span> to generate streamflow forecasts. Several ensemble approaches have been recently developed in order to take into account the different sources of errors and provide probabilistic forecasts feeding a flood forecasting system. Within this framework, the present study aims at comparing two high-resolution limited-area meteorological ensembles, covering short and medium range, obtained via different methodologies, but implemented with similar number of members, horizontal resolution (about 7 km), and driving global ensemble prediction system. The former is a multi-<span class="hlt">model</span> ensemble, based on three <span class="hlt">mesoscale</span> <span class="hlt">models</span> (BOLAM, COSMO, and WRF), while the latter, following a single-<span class="hlt">model</span> approach, is the operational ensemble forecasting system developed within the COSMO consortium, COSMO-LEPS (Limited-area Ensemble Prediction System). The meteorological <span class="hlt">models</span> are coupled with a distributed rainfall-runoff <span class="hlt">model</span> (TOPKAPI) to simulate the discharge of the Reno River (Northern Italy), for a recent severe weather episode affecting Northern Apennines. The evaluation of the ensemble systems is performed both from a meteorological perspective over the entire Northern Italy and in terms of discharge prediction over the Reno River basin during two periods of heavy precipitation between 29 November and 2 December 2008. For each period, ensemble performance has been compared at two different forecast ranges. It is found that both <span class="hlt">mesoscale</span> <span class="hlt">model</span> ensembles remarkably outperform the global ensemble for application at basin scale as the horizontal resolution plays a relevant role in modulating the precipitation distribution. Moreover, the multi-<span class="hlt">model</span> ensemble provides more informative probabilistic predictions with respect to COSMO-LEPS, since it is characterized by a larger spread especially at short lead times. A thorough analysis of the multi-<span class="hlt">model</span> results shows that this behaviour is due to the different</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2003EAEJA....11501B','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2003EAEJA....11501B"><span>Steps towards regional climate <span class="hlt">modelling</span> in tropical Westafrica using a nonhydrostatic <span class="hlt">mesoscale</span> <span class="hlt">model</span>: studies on AEW dynamics</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Born, K.; Bachner, S.; Brienen, C.</p> <p>2003-04-01</p> <p>During summer 2002, an intense observational campaign in Benin allowed identification and classification of rainfall events in the Upper Oueme valley. Hindcasts with the "Lokalmodell" (LM) of the German Weather Service showed some deficiencies in the short to medium range forecasts of observed events. In most cases, insufficient initial states especially of moisture fields could be identified as causes of failures. But also in the dynamics of the AEW, which are obviously essential for the generation of <span class="hlt">mesoscale</span> convective systems, problems seemed to arise. Concept studies with idealized initial conditions have been undertaken in order to simulate AEW dynamics and according precipitation on time scales of 1-3 months. The initial fields were changed stepwise to more realistic conditions, showing the effect of orography, SST and soil moisture on rainfall prediction on monthly timescales. Although the <span class="hlt">model</span> results in general are acceptable, still some differences to observations in location and strength of the AEJ exist.</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/abs/2013HESS...17.2107D','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2013HESS...17.2107D"><span>A flood episode in northern Italy: multi-<span class="hlt">model</span> and single-<span class="hlt">model</span> <span class="hlt">mesoscale</span> meteorological ensembles for hydrological predictions</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Davolio, S.; Miglietta, M. M.; Diomede, T.; Marsigli, C.; Montani, A.</p> <p>2013-06-01</p> <p>Numerical weather prediction <span class="hlt">models</span> can be coupled with hydrological <span class="hlt">models</span> to generate streamflow forecasts. Several ensemble approaches have been recently developed in order to take into account the different sources of errors and provide probabilistic forecasts feeding a flood forecasting system. Within this framework, the present study aims at comparing two high-resolution limited-area meteorological ensembles, covering short and medium range, obtained via different methodologies, but implemented with similar number of members, horizontal resolution (about 7 km), and driving global ensemble prediction system. The former is a multi-<span class="hlt">model</span> ensemble, based on three <span class="hlt">mesoscale</span> <span class="hlt">models</span> (BOLAM, COSMO, and WRF), while the latter, following a single-<span class="hlt">model</span> approach, is the operational ensemble forecasting system developed within the COSMO consortium, COSMO-LEPS (limited-area ensemble prediction system). The meteorological <span class="hlt">models</span> are coupled with a distributed rainfall-runoff <span class="hlt">model</span> (TOPKAPI) to simulate the discharge of the Reno River (northern Italy), for a recent severe weather episode affecting northern Apennines. The evaluation of the ensemble systems is performed both from a meteorological perspective over northern Italy and in terms of discharge prediction over the Reno River basin during two periods of heavy precipitation between 29 November and 2 December 2008. For each period, ensemble performance has been compared at two different forecast ranges. It is found that, for the intercomparison undertaken in this specific study, both <span class="hlt">mesoscale</span> <span class="hlt">model</span> ensembles outperform the global ensemble for application at basin scale. Horizontal resolution is found to play a relevant role in modulating the precipitation distribution. Moreover, the multi-<span class="hlt">model</span> ensemble provides a better indication concerning the occurrence, intensity and timing of the two observed discharge peaks, with respect to COSMO-LEPS. This seems to be ascribable to the different behaviour of the involved</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2010AtmRe..95..428S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2010AtmRe..95..428S"><span>Analysis of an extremely dense regional fog event in Eastern China 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>Shi, Chune; Yang, Jun; Qiu, Mingyan; Zhang, Hao; Zhang, Su; Li, Zihua</p> <p>2010-03-01</p> <p>An unusually dense regional advection-radiation fog event over Anhui and the surrounding provinces in eastern China during Dec. 25-27, 2006, was investigated. At its mature stage, the fog covered most Anhui and parts of the surrounding provinces, reducing visibility to 100 m or less. It lasted more than 36 consecutive hours in some places. A <span class="hlt">mesoscale</span> meteorological <span class="hlt">model</span> (MM5), together with back-trajectory analysis, was used to investigate this fog event. The observations from a field station as well as hundreds of routine stations, along with two sets of visibility computing methods, were used to quantitatively and objectively validate the MM5 simulated liquid water content (LWC) and visibility. The verifications demonstrate that MM5 has a better fog predictability for the first day compared to the second day forecast, and better fog predictability compared to dense fog predictability with regard to the probability of detection (POD) and the threat score (TS). The new visibility algorithm that uses both LWC and number density of fog droplets significantly outperforms the conventional LWC-only based one in the fog prediction in terms of the POD score, especially for dense fog prediction. The objective verification in this work is the first time conducted for MM5 fog prediction, with which we can better understand the performance of simulated temporal and spatial fog coverage. The back-trajectory and sensitivity experiments confirm that subsidence and the steady warm and moist advections from southeast and southwest maintained the dense fog while the northwesterly dry wind resulted in dissipation of the fog.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2013EGUGA..15.5524B','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2013EGUGA..15.5524B"><span>A new Approach to Estimate Initial Condition Uncertainty Structures in <span class="hlt">Mesoscale</span> <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>Bach, Liselotte; Keller, Jan D.; Hense, Andreas</p> <p>2013-04-01</p> <p> assess the corresponding uncertainty structures. Through the use of diverse norms for the measurement of the perturbation growth and different rescaling interval lengths, the technique also allows for the estimation of uncertainty patterns related to specific phenomena like convection, turbulence or fronts. Both a stationary and a progressive self breeding are implemented in a limitred-area, <span class="hlt">mesoscale</span> NWP <span class="hlt">model</span>. In several case studies (e.g., fronts, inversions, air mass convection) we present applications of the self-breeding technique to identify uncertainty structures on different temporal and spatial scales.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2005JGRE..110.6005F','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2005JGRE..110.6005F"><span>Aeolian processes in Proctor Crater on Mars: <span class="hlt">Mesoscale</span> <span class="hlt">modeling</span> of dune-forming winds</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Fenton, Lori K.; Toigo, Anthony D.; Richardson, Mark I.</p> <p>2005-06-01</p> <p>Both atmospheric <span class="hlt">modeling</span> and spacecraft imagery of Mars are now of sufficient quality that the two can be used in conjunction to acquire an understanding of regional- and local-scale aeolian processes on Mars. We apply a <span class="hlt">mesoscale</span> atmospheric <span class="hlt">model</span> adapted for use on Mars (the Mars MM5) to Proctor Crater, a 150 km diameter crater in the southern highlands. Proctor Crater contains numerous aeolian features that indicate wind direction, including a large dark dune field with reversing transverse and star dunes containing three different slipface orientations, small and older bright bedforms that are most likely transverse granule ripples, and seasonally erased dust devil tracks. Results from <span class="hlt">model</span> runs spanning a Martian year, with a horizontal grid spacing of 10 km, predict winds aligned with two of the three dune slipfaces as well as spring and summer winds matching the dust devil track orientations. The primary (most prevalent) dune slipface orientation corresponds to a fall and winter westerly wind created by geostrophic forces. The tertiary dune slipface orientation is caused by spring and summer evening katabatic flows down the eastern rim of the crater, influencing only the eastern portion of the crater floor. The dunes are trapped in the crater because the tertiary winds, enhanced by topography, counter transport from the oppositely oriented primary winds, which may have originally carried sand into the crater. The dust devil tracks are caused by light spring and summer westerly winds during the early afternoon caused by planetary rotation. The secondary dune slipface orientation is not predicted by <span class="hlt">model</span> results from either the Mars MM5 or the Geophysical Fluid Dynamics Laboratory Mars general circulation <span class="hlt">model</span>. The reason for this is not clear, and the wind circulation pattern that creates this dune slipface is not well constrained. The Mars MM5 <span class="hlt">model</span> runs do not predict stresses above the saltation threshold for dune sand of the appropriate size and</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2012ThApC.110..437P','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2012ThApC.110..437P"><span>Seasonal climate hindcasts with Eta <span class="hlt">model</span> <span class="hlt">nested</span> in CPTEC coupled ocean-atmosphere general circulation <span class="hlt">model</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Pilotto, Isabel L.; Chou, Sin Chan; Nobre, Paulo</p> <p>2012-12-01</p> <p>This work evaluates the added value of the downscaling technique employed with the Eta <span class="hlt">model</span> <span class="hlt">nested</span> in the CPTEC atmospheric general circulation <span class="hlt">model</span> and in the CPTEC coupled ocean-atmosphere general circulation <span class="hlt">model</span> (CGCM). The focus is on the austral summer season, December-January-February, with three members each year. Precipitation, latent heat flux, and shortwave radiation flux at the surface hindcast by the <span class="hlt">models</span> are compared with observational data and <span class="hlt">model</span> analyses. The global <span class="hlt">models</span> generally overestimate the precipitation over South America and tropical Atlantic. The CGCM and the <span class="hlt">nested</span> Eta (Eta + C) both produce a split in the ITCZ precipitation band. The Eta + C produces better precipitation pattern for the studied season. The Eta <span class="hlt">model</span> reduces the excessive latent heat flux generated by these global <span class="hlt">models</span>, in particular the Eta + C. Comparison against PIRATA buoys data shows that the Eta + C results in the smallest precipitation and shortwave radiation forecast errors. The Eta + C comparatively best results are though as a consequence of both: the regional <span class="hlt">model</span> resolution/physics and smaller errors on the lateral boundary conditions provided by the CGCM.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2007MAP....98...55V','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2007MAP....98...55V"><span>Simulation of heavy precipitation over Santacruz, Mumbai on 26 July 2005, using <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>Vaidya, S. S.; Kulkarni, J. R.</p> <p>2007-10-01</p> <p>An attempt has been made to simulate the unprecedented heavy precipitation of 94.4 cm in a day over Santacruz, Mumbai during 0300 UTC 26 July to 0300 UTC 27 July 2005. Three experiments have been conducted using Advanced Regional Prediction System <span class="hlt">model</span> developed by Center for Analysis and Prediction of Storms of Oklahoma University, USA. In first experiment the <span class="hlt">model</span> input at large domain size has been obtained using NCEP/NCAR reanalysis data at 2.5° × 2.5° lat. lon. resolution. In other two experiments <span class="hlt">model</span> input at large as well as at small domain sizes, have been obtained from NCEP/NCAR FNL data of 1° × 1° lat. lon. resolution. In all three experiments model’s horizontal resolution is 40 km and integration period is 30 hours from 0000 UTC 26 July 2005. Based on the temporal distribution of observed rainfall rates it is considered that the rainfall of 38.1 cm during 0900 1200 UTC on 26 July could be due to cloud burst phenomenon and 56.3 cm from 1200 UTC of 26 July to 0300 UTC of 27 July has been due to continuous regeneration of thunderstorm activity under influence of <span class="hlt">mesoscale</span> cloud complex. It is found that <span class="hlt">model</span> forecast of rainfall in first experiment was qualitatively as well as quantitatively very poor. Among other two, experiment with large domain size has predicted better rainfall values and location compared to the experiment with small domain size. The larger domain has produced rainfall of 41 cm as against observed rain rate of 56.3 cm. during 1200 UTC of 26 July to 0300 UTC of 27 July. Divergence, vorticity, vertical velocity and moisture parameters are examined in relation with the various stages of the event. The maximum values of convergence, vorticity and moisture fluxes precede the initial phase of mature stage, however vertical velocity follows the later phase of mature stage. Vorticity budget over the location of maximum rainfall, revealed the significant role of tilting term in maintenance and dissipation of the cloud complex</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://eric.ed.gov/?q=depression+AND+adolescence&pg=2&id=EJ1004545','ERIC'); return false;" href="https://eric.ed.gov/?q=depression+AND+adolescence&pg=2&id=EJ1004545"><span>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://eric.ed.gov/?q=coefficient&pg=5&id=EJ1004545','ERIC'); return false;" href="http://eric.ed.gov/?q=coefficient&pg=5&id=EJ1004545"><span>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/2011AGUFMOS43B1543H','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2011AGUFMOS43B1543H"><span><span class="hlt">Mesoscale</span> Eddies in the Solomon Sea</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Hristova, H. G.; Kessler, W. S.; McWilliams, J. C.; Molemaker, M. J.</p> <p>2011-12-01</p> <p>Water mass transformation in the strong equatorward flows through the Solomon Sea influences the properties of the Equatorial Undercurrent and subsequent cold tongue upwelling. High eddy activity in the interior Solomon Sea seen in altimetric sea surface height (SSH) and in several <span class="hlt">models</span> may provide a mechanism for these transformations. We investigate these effects using a <span class="hlt">mesoscale</span> (4-km resolution) sigma-coordinate (ROMS) <span class="hlt">model</span> of the Solomon Sea <span class="hlt">nested</span> in a basin solution, forced by a repeating seasonal cycle, and evaluated against observational data. The <span class="hlt">model</span> generates a vigorous upper layer eddy field; some of these are apparently shed as the New Guinea Coastal Undercurrent threads through the complex topography of the region, others are independent of the strong western boundary current. We diagnose the scales and vertical structure of the eddies in different parts of the Solomon Sea to illuminate their generation processes and propagation characteristics, and compare these to observed eddy statistics. Hypotheses tested are that the Solomon Sea <span class="hlt">mesoscale</span> eddies are generated locally by baroclinic instability, that the eddies are shed as the South Equatorial Current passes around and through the Solomon Island chain, that eddies are generated by the New Guinea Coastal Undercurrent, or that eddies occurring outside of the Solomon Sea propagate into the Solomon Sea. These different mechanisms have different implications for the resulting mixing and property fluxes. They also provide different interpretations for SSH signals observed from satellites (e.g., that will be observed by the upcoming SWOT satellite).</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016AGUFM.A23B0203B','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016AGUFM.A23B0203B"><span>Turbulence Dissipation Rates in the Planetary Boundary Layer from Wind Profiling Radars and <span class="hlt">Mesoscale</span> Numerical Weather Prediction <span class="hlt">Models</span> during WFIP2</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Bianco, L.; McCaffrey, K.; Wilczak, J. M.; Olson, J. B.; Kenyon, J.</p> <p>2016-12-01</p> <p>When forecasting winds at a wind plant for energy production, the turbulence parameterizations in the forecast <span class="hlt">models</span> are crucial for understanding wind plant performance. Recent research shows that the turbulence (eddy) dissipation rate in planetary boundary layer (PBL) parameterization schemes introduces significant uncertainty in the Weather Research and Forecasting (WRF) <span class="hlt">model</span>. Thus, developing the capability to measure dissipation rates in the PBL will allow for identification of weaknesses in, and improvements to the parameterizations. During a preliminary field study at the Boulder Atmospheric Observatory in spring 2015, a 915-MHz wind profiling radar (WPR) measured dissipation rates concurrently with sonic anemometers mounted on a 300-meter tower. WPR set-up parameters (e.g., spectral resolution), post-processing techniques (e.g., filtering for non-atmospheric signals), and spectral averaging were optimized to capture the most accurate Doppler spectra for measuring spectral widths for use in the computation of the eddy dissipation rates. These encouraging results lead to the implementation of the observing strategy on a 915-MHz WPR in Wasco, OR, operating as part of the Wind Forecasting Improvement Project 2 (WFIP2). These observations are compared to dissipation rates calculated from the High-Resolution Rapid Refresh <span class="hlt">model</span>, a WRF-based <span class="hlt">mesoscale</span> numerical weather prediction <span class="hlt">model</span> run for WFIP2 at 3000 m horizontal grid spacing and with a <span class="hlt">nest</span>, which has 750-meter horizontal grid spacing, in the complex terrain region of the Columbia River Gorge. The observed profiles of dissipation rates are used to evaluate the PBL parameterization schemes used in the HRRR <span class="hlt">model</span>, which are based on the <span class="hlt">modeled</span> turbulent kinetic energy and a tunable length scale.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2009ems..confE.523G','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2009ems..confE.523G"><span>Implementation of an improved urban parametrisation into the <span class="hlt">mesoscale</span> meteorology <span class="hlt">model</span> METRAS and application to London, UK</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Grawe, D.; Thompson, H. L.; Salmond, J.; Cai, X.-M.; Schluenzen, K. H.</p> <p>2009-09-01</p> <p>Urban areas have well documented effects on thermal and dynamic properties of the air as well as its chemical composition. E.g. increased heat storage, anthropogenic heat sources and radiative trapping can cause increased temperatures in the urban canopy, leading to an urban heat island with potentially adverse effects on human health and comfort. A nocturnal heat island may exacerbate the impact of summer heat waves. With growing urbanisation and in a changing climate it can be expected that these effects will increase. In order to mitigate adverse effects of the urban heat island, the strength of the heat island needs to be assessed for current levels of urbanisation, as well as for prospective urbanisation scenarios. For this purpose, the <span class="hlt">mesoscale</span> meteorology <span class="hlt">model</span> METRAS (Schlünzen, 2003) has been extended by the urban canopy <span class="hlt">model</span> BEP (Martilli et al., 2002), which has previously been validated and implemented in other <span class="hlt">mesoscale</span> meteorology <span class="hlt">models</span>. BEP parameterises the effects of the urban canopy walls and surfaces on momentum, heat and turbulent kinetic energy and takes into account very detailed specifications of building parameters, such as building height distributions and street axis orientations. The implementation of BEP in METRAS allows the use of a separate numerical grid for BEP, so that for the <span class="hlt">model</span> simulations presented in this study a very fine vertical grid with 5m cell height (compared to 20m in the METRAS grid) could be used. Greater London forms the largest urban area within the UK and has therefore been selected as the focus area for the validation of results from the improved <span class="hlt">model</span> and for selected case studies. A domain covering 100km x 100km around London has been set up with a horizontal grid resolution of 1km x 1km. Results of the validation show that the inclusion of BEP improves the performance of METRAS for most cases when compared with measurements in the urban area. This improvement can ultimately be used to provide better</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2006CSR....26.2367P','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2006CSR....26.2367P"><span>A <span class="hlt">meso-scale</span> <span class="hlt">model</span> of the central and southern North Sea: Consequences of an improved resolution</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Pohlmann, Thomas</p> <p>2006-12-01</p> <p>Results of a <span class="hlt">meso-scale</span> <span class="hlt">model</span> with a resolution of approximately 3 km of the central and southern North Sea are presented. The effect of the <span class="hlt">meso-scale</span> resolution is depicted by comparing these results with data obtained from a 20 km resolution <span class="hlt">model</span>. The validation of the <span class="hlt">model</span> by means of observed SST data and of temperature data from a hydrographic transect demonstrates that the <span class="hlt">meso-scale</span> <span class="hlt">model</span> is able to reproduce the observations reasonably well. A comparison of the 3 km resolution results with 20 km results additionally shows that the large-scale <span class="hlt">model</span> is not able to reproduce all the observed features of the SST with the same accuracy, in particular in the near-coastal areas along the Dutch and German coast. The parameters, which are investigated in more detail in this study, are temperature and salinity as well as the mean and eddy kinetic energy of the residual flow. The comparison between <span class="hlt">meso-scale</span> and large-scale results demonstrates that not only the temperature and salinity distribution but also the kinetic energy is strongly affected by the chosen grid resolution. With respect to the generated mean kinetic energy of the residual flow the refined <span class="hlt">model</span> resolution produces an increase up to 100% in the eastern parts of the North Sea, whereas in the Humber/Wash and Southern Bight region a decrease by up to 200% was obtained. In the northern part of the North Sea the finer resolution does not lead to large changes in the mean kinetic energy because here the large-scale features of the circulation dominate which also can be resolved by the large-scale <span class="hlt">model</span>. This also explains that the mean kinetic energy differences between small- and large-scale <span class="hlt">model</span> results are larger in summer than in winter because in winter due to the stronger winds the large-scale circulation is more dominant than in summer. The additional eddy kinetic energy of the residual flow (defined here as the kinetic energy contained in the spatial scales between 3 and 20 km) in general</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017EGUGA..1916070G','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017EGUGA..1916070G"><span>Spatially distributed environmental fate <span class="hlt">modelling</span> of terbuthylazine in a <span class="hlt">mesoscale</span> agricultural catchment using passive sampler data</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Gassmann, Matthias; Farlin, Julien; Gallé, Tom</p> <p>2017-04-01</p> <p>Agricultural application of herbicides often leads to significant herbicide losses to receiving rivers. The impact of agricultural practices on water pollution can be assessed by process-based reactive transport <span class="hlt">modelling</span> using catchment scale <span class="hlt">models</span>. Prior to investigations of management practices, these <span class="hlt">models</span> have to be calibrated using sampling data. However, most previous studies only used concentrations at the catchment outlet for <span class="hlt">model</span> calibration and validation. Thus, even if the applied <span class="hlt">model</span> is spatially distributed, predicted spatial differences of pesticide loss cannot be directly compared to observations. In this study, we applied the spatially distributed reactive transport <span class="hlt">model</span> Zin-AgriTra in the <span class="hlt">mesoscale</span> (78 km2) catchment of the Wark River in Luxembourg in order to simulate concentrations of terbuthylazine in river water. In contrast to former studies, we used six sampling points, equipped with passive samplers, for pesticide <span class="hlt">model</span> validation. Three samplers were located in the main channel of the river and three in smaller tributaries. At each sampling point, event mean concentration of six events from May to July 2011 were calculated by subtraction of baseflow-mass from total collected mass assuming time-proportional uptake by passive samplers. Continuous discharge measurements and high-resolution autosampling during events allowed for accurate load calculations at the outlet. Detailed information about maize cultivation in the catchment and nation-wide terbuthylazine application statistics (341 g/ha in the 3rd week of May) were used for a definition of the pesticide input function of the <span class="hlt">model</span>. The hydrological <span class="hlt">model</span> was manually calibrated to fit baseflow and spring/summer events. Substance fluxes were calibrated using a Latin Hypercube of physico-chemical substance characteristics as provided by the literature: surface soil half-lives of 10-35 d, Freundlich KOC of 150-330 ml/g, Freundlich n of 0.9 - 1 and adsorption/desorption kinetics of 20</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/16024260','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/16024260"><span><span class="hlt">Modeling</span> nucleotide evolution at the <span class="hlt">mesoscale</span>: the phylogeny of the neotropical pitvipers of the Porthidium group (viperidae: crotalinae).</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Castoe, Todd A; Sasa, Mahmood M; Parkinson, Christopher L</p> <p>2005-12-01</p> <p>We analyzed the phylogeny of the Neotropical pitvipers within the Porthidium group (including intra-specific through inter-generic relationships) using 1.4 kb of DNA sequences from two mitochondrial protein-coding genes (ND4 and cyt-b). We investigated how Bayesian Markov chain Monte-Carlo (MCMC) phylogenetic hypotheses based on this '<span class="hlt">mesoscale</span>' dataset were affected by analysis under various complex <span class="hlt">models</span> of nucleotide evolution that partition <span class="hlt">models</span> across the dataset. We develop an approach, employing three statistics (Akaike weights, Bayes factors, and relative Bayes factors), for examining the performance of complex <span class="hlt">models</span> in order to identify the best-fit <span class="hlt">model</span> for data analysis. Our results suggest that: (1) <span class="hlt">model</span> choice may have important practical effects on phylogenetic conclusions even for <span class="hlt">mesoscale</span> datasets, (2) the use of a complex partitioned <span class="hlt">model</span> did not produce widespread increases or decreases in nodal posterior probability support, and (3) most differences in resolution resulting from <span class="hlt">model</span> choice were concentrated at deeper nodes. Our phylogenetic estimates of relationships among members of the Porthidium group (genera: Atropoides, Cerrophidion, and Porthidium) resolve the monophyly of the three genera. Bayesian MCMC results suggest that Cerrophidion and Porthidium form a clade that is the sister taxon to Atropoides. In addition to resolving the intra-specific relationships among a majority of Porthidium group taxa, our results highlight phylogeographic patterns across Middle and South America and suggest that each of the three genera may harbor undescribed species diversity.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016AGUFMMR41E..01R','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016AGUFMMR41E..01R"><span><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.; Boioli, F.; Gouriet, K.; Carrez, P.; Cordier, P.</p> <p>2016-12-01</p> <p>In the lower mantle, viscosity results from the rheological behavior of its two main constituent minerals, namely (Mg,Fe)SiO3 bridgmanite 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 barely 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 interactions of dislocations. 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]. In this framework, 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 (1500-1800 K) the observed creep strain rates are controlled by the competition between dislocation glide and climb mechanisms, the former being responsible for strain production and the latter being the rate-limiting factor.Results are found in agreement with previous experimental data, confirming that the underlying physical processes are well described and permitting further investigations of MgO plasticity in the Earth's interior environment. We present the results obtained from simulations run at different temperatures and pressures within the lower mantle range of conditions. The possibility to constrain deformation with respect to time allows a characterization of the relationship between stresses and strain rates, a feature that wasn</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>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>Short-term Climate Simulations of African Easterly Waves with a Global <span class="hlt">Mesoscale</span> <span class="hlt">Model</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Shen, B. W.</p> <p>2015-12-01</p> <p>Recent high-resolution global <span class="hlt">model</span> simulations ( Shen et al., 2010a, 2010b, 2012; 2013), which were conducted to examine the role of multiscale processes associated with tropical waves in the predictability of <span class="hlt">mesoscale</span> tropical cyclones (TCs), suggested that a large-scale system (e.g., tropical waves) can provide determinism on the prediction of TC genesis, making it possible to extend the lead time of genesis predictions. Selected cases include the relationship between (i) TC Nargis (2008) and an Equatorial Rossby wave; (ii) Hurricane Helene (2006) and an intensifying African Easterly Wave (AEW); (iii) Twin TCs (2002) and a mixed Rossby-gravity wave during an active phase of the Madden Julian Oscillation (MJO); (iv) Hurricane Sandy (2012) and tropical waves during an active phase of the MJO. In this talk, thirty-day simulations with different <span class="hlt">model</span> configurations are presented to examine the <span class="hlt">model</span>'s ability to simulate AEWs and MJOs and their association with tropical cyclogenesis. I will first discuss the simulations of the initiation and propagation of 6 consecutive AEWs in late August 2006 and the mean state of the African easterly jet (AEJ) over both Africa and downstream in the tropical Atlantic. By comparing our simulations with NCEP analysis and satellite data (e.g., TRMM), it is shown that the statistical characteristics of individual AEWs are realistically simulated with larger errors in the 5th and th AEWs. Results from the sensitivity experiments suggest the following: 1) accurate representations of non-linear interactions between the atmosphere and land processes are crucial for improving the simulations of the AEWs and the AEJ; 2) improved simulations of an individual AEW and its interaction with local environments (e.g., the Guinea Highlands) could provide determinism for hurricane formation downstream. Of interest is the potential to extend the lead time for predicting hurricane formation (e.g., a lead time of up to 22 days) as the 4th AEW is</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016AGUFMSM51G..07H','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016AGUFMSM51G..07H"><span>Determination of <span class="hlt">meso-scale</span> magnetotail structure using nonlinear dynamics <span class="hlt">modeling</span> and Cluster data</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Holland, D. L.; Martin, R. F., Jr.; MacDonna, K.; Starzyk, M.; Calamari, C.</p> <p>2016-12-01</p> <p>A frequently used approximation for the quiet-time magnetotail magnetic field is the modified Harris <span class="hlt">model</span>, B =B0[tanh(z/d)ex +bzez] where B0 is the magnetic field strength far from the sheet, d is the scale length of the current sheet thickness and bz is the ratio of the magnitude of the field at the mid-plane to the asymptotic field. This <span class="hlt">model</span> is easily generalized to account for the case of a bifurcated current sheet. Simulations of nonlinear charged particle dynamics in the modified Harris field predict the existence of a series of peak in the ion distribution function who's separation scales as the fourth root of the normalized ion energy which in turn depends on the combination of parameters. For the bifurcated sheet, the resonance peaks energies are shifted due to the decreased curvature of the magnetic field in the vicinity of the midplane. Measurements of the peaks in the ion distribution function or differential particle flux yields a value for s, however, an independent measurement of either bz or d is still needed to determine the <span class="hlt">meso-scale</span> current sheet structure. In previous studies we have used Geotail single space craft data to obtain a rough estimate of bz and used the resonance signature to determine the current sheet thickness. Numerous observational studies have used various methods and multipoint Cluster data to determine d, but not bz. Since both parameters are important in understanding the particle dynamics, in this study we have used the higher multipoint measurements in conjunction with nonlinear dynamics to significantly reduce the uncertainties in the measurements. In particular, we use two different methods to determine each of the parameters B0, bz and d, and use the locations of the resonance peaks as a consistency check on the results. The measurements of the current sheet parameters are in good agreement with previous studies, but with a significantly lower uncertainty, particularly in the determination of bz. We also examine the</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2004JAtS...61..422M','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2004JAtS...61..422M"><span>Observations of Particle Size and Phase in Tropical Cyclones: Implications for <span class="hlt">Mesoscale</span> <span class="hlt">Modeling</span> of Microphysical Processes.</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>McFarquhar, Greg M.; Black, Robert A.</p> <p>2004-02-01</p> <p><span class="hlt">Mesoscale</span> <span class="hlt">model</span> simulations of tropical cyclones are sensitive to representations of microphysical processes, such as fall velocities of frozen hydrometeors. The majority of microphysical parameterizations are based on observations obtained in clouds not associated with tropical cyclones, and hence their suitability for use in simulations of tropical cyclones is not known. Here, representations of mass-weighted fall speed Vm for snow and graupel are examined to show that parameters describing the exponential size distributions and fall speeds of individual hydrometeors [through use of relations such as V(D) = aDb] are identically important for determining Vm. The a and b coefficients are determined by the composition and shape of snow and graupel particles; past <span class="hlt">modeling</span> studies have not adequately considered the possible spread of a and b values. Step variations in these coefficients, associated with different fall velocity regimes, however, do not have a large impact on Vm for observed size distributions in tropical cyclones and the values of a and b used here, provided that coefficients are chosen in accordance with the sizes where the majority of mass occurs. New parameterizations for Vm are developed such that there are no inconsistencies between the diameters used to define the mass, number concentration, and fall speeds of individual hydrometeors. Effects due to previous inconsistencies in defined diameters on mass conversion rates between different hydrometeor classes (e.g., snow, graupel, cloud ice) are shown to be significant.In situ microphysical data obtained in Hurricane Norbert (1984) and Hurricane Emily (1987) with two-dimensional cloud and precipitation probes are examined to determine typical size distributions of snow and graupel particles near the melting layer. Although well represented by exponential functions, there are substantial differences in how the intercept and slope of these distributions vary with mass content when compared to</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://eric.ed.gov/?q=simulation+AND+method+AND+mathematic&id=EJ1083301','ERIC'); return false;" href="http://eric.ed.gov/?q=simulation+AND+method+AND+mathematic&id=EJ1083301"><span>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> </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('https://eric.ed.gov/?q=applications+AND+Logistics&pg=4&id=EJ959349','ERIC'); return false;" href="https://eric.ed.gov/?q=applications+AND+Logistics&pg=4&id=EJ959349"><span>Application of a Multidimensional <span class="hlt">Nested</span> Logit <span class="hlt">Model</span> to Multiple-Choice Test Items</span></a></p> <p><a target="_blank" href="http://www.eric.ed.gov/ERICWebPortal/search/extended.jsp?_pageLabel=advanced">ERIC Educational Resources Information Center</a></p> <p>Bolt, Daniel M.; Wollack, James A.; Suh, Youngsuk</p> <p>2012-01-01</p> <p><span class="hlt">Nested</span> logit <span class="hlt">models</span> have been presented as an alternative to multinomial logistic <span class="hlt">models</span> for multiple-choice test items (Suh and Bolt in "Psychometrika" 75:454-473, 2010) and possess a mathematical structure that naturally lends itself to evaluating the incremental information provided by attending to distractor selection in scoring. One potential…</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.fs.usda.gov/treesearch/pubs/53116','TREESEARCH'); return false;" href="https://www.fs.usda.gov/treesearch/pubs/53116"><span>Transferability of habitat suitability <span class="hlt">models</span> for <span class="hlt">nesting</span> woodpeckers associated with wildfire</span></a></p> <p><a target="_blank" href="http://www.fs.usda.gov/treesearch/">Treesearch</a></p> <p>Quresh S. Latif; Vicki Saab; Jeff P. Hollenbeck; Jonathan G. Dudley</p> <p>2016-01-01</p> <p>Following wildfire, forest managers are challenged with meeting both socioeconomic demands (e.g., salvage logging) and mandates requiring habitat conservation for disturbance-associated wildlife (e.g., woodpeckers). Habitat suitability <span class="hlt">models</span> for <span class="hlt">nesting</span> woodpeckers can be informative, but tests of <span class="hlt">model</span> transferability are needed to understand how broadly...</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><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://adsabs.harvard.edu/abs/2007AGUSMOS51D..04A','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2007AGUSMOS51D..04A"><span>IAS <span class="hlt">Mesoscale</span> Surface Circulation Observed Through Satellite Altimetry and its Influence in a Small Scale, Coastal Domain, Studied with a ROMS <span class="hlt">Model</span> of the Cariaco Basin.</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Alvera-Azcarate, A.; Barth, A.; Virmani, J. I.; Weisberg, R. H.</p> <p>2007-05-01</p> <p>The Intra-Americas Sea (IAS) surface circulation is characterized by large scale currents. The Caribbean current, which originates in the Lesser Antilles, travels westwards through the Caribbean Sea and eastern Mexico and passes through the Gulf of Mexico to finally form the Gulf Stream. This complex system of currents is also characterized by a high <span class="hlt">mesoscale</span> variability, such as eddies and meanders. The objectives of this work are twofold: first, the multi-scale surface circulation of the IAS is described using satellite altimetry. The topographic influence of the different basins forming the IAS, the characteristic time and spatial scales, and the time variability of the surface circulation will be addressed. The second objective is to analyze the influence of this large scale circulation on a small scale coastal domain with a ROMS-based <span class="hlt">model</span> of the Cariaco basin (Venezuela). Cariaco is a deep (1400 m), semi-enclosed basin connected to the open ocean by two shallow channels (Tortuga and Centinela Channels). Its connection with the open sea, and therefore the ventilation of the basin, occurs in the surface layers. The Cariaco ROMS <span class="hlt">model</span> will be used to study the exchanges of mass, heat and salt through the channels. A 1/60 degree ROMS <span class="hlt">model</span> <span class="hlt">nested</span> in the global 1/12 degree HYCOM <span class="hlt">model</span> from the Naval Research Laboratory will be used for this study. In addition, a series of observations (satellite altimetry and in situ temperature, salinity and velocity data), will be used to assess the influence of the Caribbean circulation on the basin.</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><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('https://www.ncbi.nlm.nih.gov/pubmed/26113190','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/26113190"><span>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>2015-09-07</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. Copyright © 2015 Elsevier Ltd. All rights reserved.</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><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://www.osti.gov/scitech/servlets/purl/1127267','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/servlets/purl/1127267"><span>Using <span class="hlt">Mesoscale</span> Weather <span class="hlt">Model</span> Output as Boundary Conditions for Atmospheric Large-Eddy Simulations and Wind-Plant Aerodynamic Simulations (Presentation)</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Churchfield, M. J.; Michalakes, J.; Vanderwende, B.; Lee, S.; Sprague, M. A.; Lundquist, J. K.; Moriarty, P. J.</p> <p>2013-10-01</p> <p>Wind plant aerodynamics are directly affected by the microscale weather, which is directly influenced by the <span class="hlt">mesoscale</span> weather. Microscale weather refers to processes that occur within the atmospheric boundary layer with the largest scales being a few hundred meters to a few kilometers depending on the atmospheric stability of the boundary layer. <span class="hlt">Mesoscale</span> weather refers to large weather patterns, such as weather fronts, with the largest scales being hundreds of kilometers wide. Sometimes microscale simulations that capture <span class="hlt">mesoscale</span>-driven variations (changes in wind speed and direction over time or across the spatial extent of a wind plant) are important in wind plant analysis. In this paper, we present our preliminary work in coupling a <span class="hlt">mesoscale</span> weather <span class="hlt">model</span> with a microscale atmospheric large-eddy simulation <span class="hlt">model</span>. The coupling is one-way beginning with the weather <span class="hlt">model</span> and ending with a computational fluid dynamics solver using the weather <span class="hlt">model</span> in coarse large-eddy simulation mode as an intermediary. We simulate one hour of daytime moderately convective microscale development driven by the <span class="hlt">mesoscale</span> data, which are applied as initial and boundary conditions to the microscale domain, at a site in Iowa. We analyze the time and distance necessary for the smallest resolvable microscales to develop.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017ACP....17.7083H','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017ACP....17.7083H"><span>Evaluation of large-eddy simulations forced with <span class="hlt">mesoscale</span> <span class="hlt">model</span> output for a multi-week period during a measurement campaign</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Heinze, Rieke; Moseley, Christopher; Böske, Lennart Nils; Muppa, Shravan Kumar; Maurer, Vera; Raasch, Siegfried; Stevens, Bjorn</p> <p>2017-06-01</p> <p>Large-eddy simulations (LESs) of a multi-week period during the HD(CP)2 (High-Definition Clouds and Precipitation for advancing Climate Prediction) Observational Prototype Experiment (HOPE) conducted in Germany are evaluated with respect to mean boundary layer quantities and turbulence statistics. Two LES <span class="hlt">models</span> are used in a semi-idealized setup through forcing with <span class="hlt">mesoscale</span> <span class="hlt">model</span> output to account for the synoptic-scale conditions. Evaluation is performed based on the HOPE observations. The mean boundary layer characteristics like the boundary layer depth are in a principal agreement with observations. Simulating shallow-cumulus layers in agreement with the measurements poses a challenge for both LES <span class="hlt">models</span>. Variance profiles agree satisfactorily with lidar measurements. The results depend on how the forcing data stemming from <span class="hlt">mesoscale</span> <span class="hlt">model</span> output are constructed. The mean boundary layer characteristics become less sensitive if the averaging domain for the forcing is large enough to filter out <span class="hlt">mesoscale</span> fluctuations.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://archive.usgs.gov/archive/sites/www.nwrc.usgs.gov/wdb/pub/hsi/hsi-151.pdf','USGSPUBS'); return false;" href="https://archive.usgs.gov/archive/sites/www.nwrc.usgs.gov/wdb/pub/hsi/hsi-151.pdf"><span>Habitat Suitability Index <span class="hlt">Models</span>: Diamondback terrapin (<span class="hlt">nesting</span>) - Atlantic coast</span></a></p> <p><a target="_blank" href="http://pubs.er.usgs.gov/pubs/index.jsp?view=adv">USGS Publications Warehouse</a></p> <p>Palmer, William M.; Cordes, Carroll L.</p> <p>1988-01-01</p> <p>A review and synthesis of existing information were used to develop a Habitat Suitability Index (HSI) <span class="hlt">model</span> for the diamondback terrapin (Malaclemys terrapin). The <span class="hlt">model</span> consolidates habitat use information into a framework appropriate for field application, and is scaled to produce an index between 0.0 (unsuitable habitat) to 1.0 (optimum habitat). HSI <span class="hlt">models</span> are designed to be used with Habitat Evaluation Procedures previously developed by the U.S. Fish and Wildlife Service.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.dtic.mil/docs/citations/ADA322694','DTIC-ST'); return false;" href="http://www.dtic.mil/docs/citations/ADA322694"><span>Habitat Suitability Index <span class="hlt">Models</span>: Diamondback Terrapin (<span class="hlt">Nesting</span>)--Atlantic Coast.</span></a></p> <p><a target="_blank" href="http://www.dtic.mil/">DTIC Science & Technology</a></p> <p></p> <p>1988-03-01</p> <p>The diamondback terrapin occurs in a narrow strip of salt and brackish water habitats along the Atlantic and gulf coasts of the United States. A...review and synthesis of existing information were used to develop a Habitat Suitability Index (HSI) <span class="hlt">model</span> for the diamondback terrapin (Malaclemys... terrapin ). The <span class="hlt">model</span> is scaled to produce an index between 0.0 (unsuitable habitat) and 1.0 (optimum habitat). HSI <span class="hlt">models</span> are designed to be used with</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2009EGUGA..11..933H','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2009EGUGA..11..933H"><span>Coastal (Sub)<span class="hlt">Mesoscale</span> Eddies in the Gulf of Lion</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Hu, Z. Y.; Doglioli, A. M.; Petrenko, A. A.; Marsaleix, P.; Dekeyser, I.</p> <p>2009-04-01</p> <p>The LAgrangian Transport EXperiment (LATEX) project (2008-2011) has been initiated in order to study the role of (sub)<span class="hlt">mesoscale</span> structures on shelf-offshore exchanges in the Gulf of Lion. The strategy will combine use of data from an inert tracer release (SF6), Lagrangian drifters, satellites and Eulerian moorings with numerical <span class="hlt">modeling</span>. In this work, we present a shelf-scale <span class="hlt">model</span> of high resolution (1-km) <span class="hlt">nested</span> in a regional-scale <span class="hlt">model</span> (3-km). We use an upwind-type advection-diffusion scheme, in which the numerical diffusion term is adjusted by an attenuation coefficient. Sensitivity tests have been carried out, varying the <span class="hlt">model</span> spatial resolution and the attenuation coefficient to reproduce the (sub)<span class="hlt">mesoscale</span> structures. A wavelet technique is applied on <span class="hlt">model</span> outputs to identify eddies and to define their area, position and tracking duration. Comparisons between the <span class="hlt">modeled</span> eddies and those observed by satellite have allowed us to choose the best <span class="hlt">model</span> configuration. With this setup, single and combined effects of wind forcing, bathymetry and <span class="hlt">mesoscale</span> circulation are investigated to propose a generation process of these simulated eddies. Then, simulations are run for long period to obtain annual variability and statistics of the coastal eddies. These coastal (sub)<span class="hlt">mesoscale</span> eddies potentially interact with the distal plume of the Rhône river and the Northern Current. Numerical <span class="hlt">modeling</span> sets the foundation to understand the eddies' dynamics and helps us set up the sampling strategy of the cruises. The in situ measurements combined with the <span class="hlt">modeling</span> results will allow us to evaluate the eddies' potential impact on the coastal-offshore transfer of matter and energy.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/19920002516','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19920002516"><span>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.ncbi.nlm.nih.gov/pubmed/25809926','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/25809926"><span>Development of an Interspecies <span class="hlt">Nested</span> Dose-Response <span class="hlt">Model</span> for Mycobacterium avium subspecies paratuberculosis.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Breuninger, Kirk J; Weir, Mark H</p> <p>2015-08-01</p> <p>Mycobacterium avium subspecies paratuberculosis (MAP) causes chronic inflammation of the intestines in humans, ruminants, and other species. It is the causative agent of Johne's disease in cattle, and has been implicated as the causative agent of Crohn's disease in humans. To date, no quantitative microbial risk assessment (QMRA) for MAP utilizing a dose-response function exists. The objective of this study is to develop a <span class="hlt">nested</span> dose-response <span class="hlt">model</span> for infection from oral exposure to MAP utilizing data from the peer-reviewed literature. Four studies amenable to dose-response <span class="hlt">modeling</span> were identified in the literature search and optimized to the one-parameter exponential or two-parameter beta-Poisson dose-response <span class="hlt">models</span>. A <span class="hlt">nesting</span> analysis was performed on all permutations of the candidate data sets to determine the acceptability of pooling data sets across host species. Three of four data sets exhibited goodness of fit to at least one <span class="hlt">model</span>. All three data sets exhibited good fit to the beta-Poisson <span class="hlt">model</span>, and one data set exhibited goodness of fit, and best fit, to the exponential <span class="hlt">model</span>. Two data sets were successfully <span class="hlt">nested</span> using the beta-Poisson <span class="hlt">model</span> with parameters α = 0.0978 and N50 = 2.70 × 10(2) CFU. These data sets were derived from sheep and red deer host species, indicating successful interspecies <span class="hlt">nesting</span>, and demonstrate the highly infective nature of MAP. The <span class="hlt">nested</span> dose-response <span class="hlt">model</span> described should be used for future QMRA research regarding oral exposure to MAP. © 2015 Society for Risk Analysis.</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>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>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>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://adsabs.harvard.edu/abs/2015FlDyR..47e1401I','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015FlDyR..47e1401I"><span>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://hdl.handle.net/2060/20030063974','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20030063974"><span>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('https://www.ncbi.nlm.nih.gov/pubmed/28772568','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/28772568"><span><span class="hlt">Mesoscale</span> Characterization of Fracture Properties of Steel Fiber-Reinforced Concrete Using a Lattice-Particle <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>Montero-Chacón, Francisco; Cifuentes, Héctor; Medina, Fernando</p> <p>2017-02-21</p> <p>This work presents a lattice-particle <span class="hlt">model</span> for the analysis of steel fiber-reinforced concrete (SFRC). In this approach, fibers are explicitly <span class="hlt">modeled</span> and connected to the concrete matrix lattice via interface elements. The interface behavior was calibrated by means of pullout tests and a range for the bond properties is proposed. The <span class="hlt">model</span> was validated with analytical and experimental results under uniaxial tension and compression, demonstrating the ability of the <span class="hlt">model</span> to correctly describe the effect of fiber volume fraction and distribution on fracture properties of SFRC. The lattice-particle <span class="hlt">model</span> was integrated into a hierarchical homogenization-based scheme in which macroscopic material parameters are obtained from <span class="hlt">mesoscale</span> simulations. Moreover, a representative volume element (RVE) analysis was carried out and the results shows that such an RVE does exist in the post-peak regime and until localization takes place. Finally, the multiscale upscaling strategy was successfully validated with three-point bending tests.</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('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=5459137','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=5459137"><span><span class="hlt">Mesoscale</span> Characterization of Fracture Properties of Steel Fiber-Reinforced Concrete Using a Lattice–Particle <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>Montero-Chacón, Francisco; Cifuentes, Héctor; Medina, Fernando</p> <p>2017-01-01</p> <p>This work presents a lattice–particle <span class="hlt">model</span> for the analysis of steel fiber-reinforced concrete (SFRC). In this approach, fibers are explicitly <span class="hlt">modeled</span> and connected to the concrete matrix lattice via interface elements. The interface behavior was calibrated by means of pullout tests and a range for the bond properties is proposed. The <span class="hlt">model</span> was validated with analytical and experimental results under uniaxial tension and compression, demonstrating the ability of the <span class="hlt">model</span> to correctly describe the effect of fiber volume fraction and distribution on fracture properties of SFRC. The lattice–particle <span class="hlt">model</span> was integrated into a hierarchical homogenization-based scheme in which macroscopic material parameters are obtained from <span class="hlt">mesoscale</span> simulations. Moreover, a representative volume element (RVE) analysis was carried out and the results shows that such an RVE does exist in the post-peak regime and until localization takes place. Finally, the multiscale upscaling strategy was successfully validated with three-point bending tests. PMID:28772568</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>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://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=90574894&CFTOKEN=61790817','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=90574894&CFTOKEN=61790817"><span>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('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>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://cfpub.epa.gov/si/si_public_record_report.cfm?dirEntryId=266456&keyword=avian&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','EPA-EIMS'); return false;" href="http://cfpub.epa.gov/si/si_public_record_report.cfm?dirEntryId=266456&keyword=avian&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"><span>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://eric.ed.gov/?q=ulrich+AND+model&pg=3&id=EJ910601','ERIC'); return false;" href="http://eric.ed.gov/?q=ulrich+AND+model&pg=3&id=EJ910601"><span>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.fs.usda.gov/treesearch/pubs/29210','TREESEARCH'); return false;" href="https://www.fs.usda.gov/treesearch/pubs/29210"><span>Habitat suitability <span class="hlt">models</span> for cavity-<span class="hlt">nesting</span> birds in a postfire landscape</span></a></p> <p><a target="_blank" href="http://www.fs.usda.gov/treesearch/">Treesearch</a></p> <p>Robin E. Russell; Victoria A. Saab; Jonathan G. Dudley</p> <p>2007-01-01</p> <p><span class="hlt">Models</span> of habitat suitability in postfire landscapes are needed by land managers to make timely decisions regarding postfire timber harvest and other management activities. Many species of cavity-<span class="hlt">nesting</span> birds are dependent on postfire landscapes for breeding and other aspects of their life history and are responsive to postfire management activities (e.g., timber...</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/26543578','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/26543578"><span>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.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2010AGUFM.B31D0340J','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2010AGUFM.B31D0340J"><span>Quantification of Biosphere and Anthropogenic CO2 using WRF-VPRM <span class="hlt">Mesoscale</span> Transport and Biosphere <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>Jamroensan, A.; Ahmadov, R.; Petron, G.; Carmichael, G. R.; Andrews, A. E.; Sweeney, C.; Kretschmer, R.; Gerbig, C.; Olsen, L. M.; Stanier, C. O.</p> <p>2010-12-01</p> <p>Understanding of carbon dioxide (CO2) regional sources and sinks is crucial for estimating current and future carbon budgets. Here, we evaluate the skill of a diagnostic biosphere <span class="hlt">model</span>, Vegetation Photosynthesis and Respiration <span class="hlt">Model</span>, VPRM, online-coupled with the <span class="hlt">mesoscale</span> Weather Research and Forecasting <span class="hlt">model</span> WRF to simulate CO2 biosphere fluxes and total CO2 concentrations in the Midwest, USA with high spatial resolution (4km x 4km horizontally, 30 vertical levels of which 9 are below 1.5 km). Extensive evaluation data and bottom up inventories are available for this area and period from the Mid Continent Intensive (e.g. RING2 measurements, http://www.ring2.psu.edu/) Preliminary results of July 2008 yield average net fluxes over the State of Iowa of NEE in June, July, and August 2008 of -0.7 µmol/m2, -5.8 µmol/m2, and -6.3 µmol/m2, respectively. Results at two Ameriflux sites in Ames, Iowa (Brook Field sites 10 and 11), with the current VPRM parameters simulated lower GEE and respiration fluxes compared to fluxes of NOAA Carbon Tracker products and observations. While absolute values of gross fluxes in WRF-VPRM are lower than the limited observations and Carbon Tracker, the net flux in WRF-VPRM generally exceeds that of Carbon Tracker for the summer 2008 period. CO2 concentrations simulated with the above fluxes and 4-km WRF-VPRM were compared to hourly CO2 data from NOAA tall tower at West Branch Iowa (WBI). Vulcan anthropogenic emissions (Gurney, 2009) were used included as well together with initial condition and boundary condition from Carbon Tracker (Peters et al, 2007) so as to give a simulated total CO2 concentration. Two planetary boundary layer schemes, YSU and MYJ, in WRF version 3.0.1 were tested in these CO2 simulations. The MYJ scheme predicted better results for wind speed and wind direction than YSU scheme. When compared to CO2 measurement at WBI (hourly average at 30m, 99m, and 379m above ground), both schemes performed similarly, with the</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2003EAEJA....12419A','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2003EAEJA....12419A"><span>Diagnosis of precipitation variability in <span class="hlt">nested</span> regional climate <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>Arritt, R.; PIRCS Participants</p> <p>2003-04-01</p> <p>In order to assess reasons for <span class="hlt">model-to-model</span> variability of precipitation in regional climate <span class="hlt">models</span> (RCMs) we have evaluated 60-day simulations over the continental U.S. in June-July 1993 from thirteen simulations using different RCMs. The hydrologic cycles in the simulations were compared both to each other and to observations for a subregion of the upper Mississippi River Basin (UMRB), containing the region of maximum 60-day accumulated precipitation in all RCMs and station reports. All RCMs produced positive precipitation (P) minus evaporation (E) and recycling ratios that were within the range estimated from observations. RCM E was sensitive to radiation parameterization, but inter-<span class="hlt">model</span> variability of E was spread evenly about estimates of observed E. In contrast, most RCMs produced P that was below the range of P from observations, accounting for the low values of simulated P-E compared to observations. Nine of the 13 RCMs reproduced qualitatively the observed daily cycles of P and moisture flux convergence (C), with maximum P and C occurring simultaneously at night. Three of the four driest RCMs had maximum precipitation in the afternoon, suggesting that in these RCMs afternoon destabilization by insolation had excessive influence on production of precipitation. Thus a key indicator of the ability of RCMs in this collection to properly simulate P is their ability to simulate the observed nocturnal maximum of P, indicating that the failure to resolve the diurnal cycle is closely related to overall bias in precipitation.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=19840043466&hterms=Kaplan&qs=N%3D0%26Ntk%3DAll%26Ntx%3Dmode%2Bmatchall%26Ntt%3DW.%2BKaplan','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=19840043466&hterms=Kaplan&qs=N%3D0%26Ntk%3DAll%26Ntx%3Dmode%2Bmatchall%26Ntt%3DW.%2BKaplan"><span>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('https://ntrs.nasa.gov/search.jsp?R=19840043466&hterms=weather+forecasting&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D70%26Ntt%3Dweather%2Bforecasting','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=19840043466&hterms=weather+forecasting&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D70%26Ntt%3Dweather%2Bforecasting"><span>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/2017AtmEn.163..155S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017AtmEn.163..155S"><span><span class="hlt">Modelling</span> NOX concentrations through CFD-RANS in an urban hot-spot using high resolution traffic emissions and meteorology 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>Sanchez, Beatriz; Santiago, Jose Luis; Martilli, Alberto; Martin, Fernando; Borge, Rafael; Quaassdorff, Christina; de la Paz, David</p> <p>2017-08-01</p> <p>Air quality management requires more detailed studies about air pollution at urban and local scale over long periods of time. This work focuses on obtaining the spatial distribution of NOx concentration averaged over several days in a heavily trafficked urban area in Madrid (Spain) using a computational fluid dynamics (CFD) <span class="hlt">model</span>. A methodology based on weighted average of CFD simulations is applied computing the time evolution of NOx dispersion as a sequence of steady-state scenarios taking into account the actual atmospheric conditions. The inputs of emissions are estimated from the traffic emission <span class="hlt">model</span> and the meteorological information used is derived from a <span class="hlt">mesoscale</span> <span class="hlt">model</span>. Finally, the computed concentration map correlates well with 72 passive samplers deployed in the research area. This work reveals the potential of using urban <span class="hlt">mesoscale</span> simulations together with detailed traffic emissions so as to provide accurate maps of pollutant concentration at microscale using CFD simulations.</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><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('https://ntrs.nasa.gov/search.jsp?R=19850054706&hterms=assimilation+methods&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D10%26Ntt%3Dassimilation%2Bmethods','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=19850054706&hterms=assimilation+methods&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D10%26Ntt%3Dassimilation%2Bmethods"><span>Variational assimilation of VAS data into a <span class="hlt">mesoscale</span> <span class="hlt">model</span> Assimilation method and sensitivity experiments. [Visible Infrared Spin-Scan Radiometer Atmospheric Sounder</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Cram, J. M.; Kaplan, M. L.</p> <p>1985-01-01</p> <p>The assimilation of temperature and moisture gradient information from the Visible IR Spin-Scan Radiometer's Atmospheric Sounder (VAS) into a <span class="hlt">mesoscale</span> <span class="hlt">model</span> is presently undertaken by means of a variational method and followed by tests of the sensitivity of both diabatic and adiabatic versions of the <span class="hlt">model</span> to VAS data assimilations for the case of July 20-21, 1981. The synoptic scale effects of the assimilation of VAS data are noted to be negligible; the greatest impact was instead on <span class="hlt">mesoscale</span> forecasts of convective instability patterns. The additional assimilation of relative humidity gradients did not significantly change the patterns of the forecast instabilities. The greatest improvements from assimilation resulted from the resolution of the strong <span class="hlt">mesoscale</span> temperature gradients by the asynoptic VAS data.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015EGUGA..1712530K','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015EGUGA..1712530K"><span>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('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4084988','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4084988"><span>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('https://www.ncbi.nlm.nih.gov/pubmed/24999969','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/24999969"><span>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="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</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.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017RMRE...50.2345X','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017RMRE...50.2345X"><span>The Influence of Temperature on Time-Dependent Deformation and Failure in Granite: A <span class="hlt">Mesoscale</span> <span class="hlt">Modeling</span> Approach</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Xu, T.; Zhou, G. L.; Heap, Michael J.; Zhu, W. C.; Chen, C. F.; Baud, Patrick</p> <p>2017-09-01</p> <p>An understanding of the influence of temperature on brittle creep in granite is important for the management and optimization of granitic nuclear waste repositories and geothermal resources. We propose here a two-dimensional, thermo-mechanical numerical <span class="hlt">model</span> that describes the time-dependent brittle deformation (brittle creep) of low-porosity granite under different constant temperatures and confining pressures. The <span class="hlt">mesoscale</span> <span class="hlt">model</span> accounts for material heterogeneity through a stochastic local failure stress field, and local material degradation using an exponential material softening law. Importantly, the <span class="hlt">model</span> introduces the concept of a mesoscopic renormalization to capture the co-operative interaction between microcracks in the transition from distributed to localized damage. The <span class="hlt">mesoscale</span> physico-mechanical parameters for the <span class="hlt">model</span> were first determined using a trial-and-error method (until the <span class="hlt">modeled</span> output accurately captured mechanical data from constant strain rate experiments on low-porosity granite at three different confining pressures). The thermo-physical parameters required for the <span class="hlt">model</span>, such as specific heat capacity, coefficient of linear thermal expansion, and thermal conductivity, were then determined from brittle creep experiments performed on the same low-porosity granite at temperatures of 23, 50, and 90 °C. The good agreement between the <span class="hlt">modeled</span> output and the experimental data, using a unique set of thermo-physico-mechanical parameters, lends confidence to our numerical approach. Using these parameters, we then explore the influence of temperature, differential stress, confining pressure, and sample homogeneity on brittle creep in low-porosity granite. Our simulations show that increases in temperature and differential stress increase the creep strain rate and therefore reduce time-to-failure, while increases in confining pressure and sample homogeneity decrease creep strain rate and increase time-to-failure. We anticipate that the</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017PApGe.tmp..175K','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017PApGe.tmp..175K"><span>Interaction of Sea Breeze and Deep Convection over the Northeastern Adriatic Coast: An Analysis of Sensitivity Experiments Using a High-Resolution <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>Kehler-Poljak, Gabrijela; Telišman Prtenjak, Maja; Kvakić, Marko; Šariri, Kristina; Večenaj, Željko</p> <p>2017-07-01</p> <p>This study investigates the sensitivity of a high-resolution <span class="hlt">mesoscale</span> atmospheric <span class="hlt">model</span> in the <span class="hlt">model</span> reproduction of thermally induced local wind (i.e., sea breezes, SB) on the development of deep convection (Cb). The three chosen cases are simulated by the Weather and Research Forecasting (WRF-ARW) <span class="hlt">model</span> at three (<span class="hlt">nested</span>) <span class="hlt">model</span> domains, whereas the area of the interest is Istria (peninsula in the northeastern Adriatic). The sensitivity tests are accomplished by modifying (1) the <span class="hlt">model</span> setup, (2) the <span class="hlt">model</span> topography and (3) the sea surface temperature (SST) distribution. The first set of simulations (over the three 1.5-day periods during summer) is conducted by modifying the <span class="hlt">model</span> setup, i.e., microphysics and the boundary layer parameterizations. The same events are simulated with the modified topography where the mountain heights in Istria are reduced to 30% of their initial height. The SST distribution has two representations in the <span class="hlt">model</span>: a constant SST field from the ECMWF skin temperature analysis and a varying SST field, which is provided by hourly geostationary satellite data. A comprehensive set of numerical experiments is statistically analyzed through several different approaches (i.e., the standard statistical measures, the spectral method and the image moment analysis). The overall <span class="hlt">model</span> evaluation of each <span class="hlt">model</span> setup revealed certain advantages of one <span class="hlt">model</span> setup over the others. The numerical tests with the modified topography showed the influence of reducing the mountains heights on the pre-thunderstorm characteristics due to: (1) decrease of sensible heat flux and mid-tropospheric moisture and (2) change of slope-SB wind system. They consequently affect the evolution and dimensions of SBs and the features of the thunderstorm itself: timing, location and intensity (weaker storm). The implementation of the varying SST field in the <span class="hlt">model</span> have an impact on the characteristics and dynamics of the SB and finally on the accuracy of Cb evolution</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_20");'>20</a></li> <li><a href="#" onclick='return showDiv("page_21");'>21</a></li> <li class="active"><span>22</span></li> <li><a href="#" onclick='return showDiv("page_23");'>23</a></li> <li><a href="#" onclick='return showDiv("page_24");'>24</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_22 --> <div id="page_23" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_21");'>21</a></li> <li><a href="#" onclick='return showDiv("page_22");'>22</a></li> <li class="active"><span>23</span></li> <li><a href="#" onclick='return showDiv("page_24");'>24</a></li> <li><a href="#" onclick='return showDiv("page_25");'>25</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="441"> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017EGUGA..1911392T','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017EGUGA..1911392T"><span>Mass and tracer transport within oceanic Lagrangian coherent vortices as diagnosed in a global <span class="hlt">mesoscale</span> eddying climate <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>Tarshish, Nathaniel; Abernathey, Ryan; Dufour, Carolina; Frenger, Ivy; Griffies, Stephen</p> <p>2017-04-01</p> <p>Transient ocean <span class="hlt">mesoscale</span> fluctuations play a central role in the global climate system, transporting climate relevant tracers such as heat and carbon. In satellite observations and numerical simulations, <span class="hlt">mesoscale</span> vortices feature prominently as collectively rotating regions that remain visibly coherent. Prior studies on transport from ocean vortices typically rely on Eulerian identification methods, in which vortices are identified by selecting closed contours of Eulerian fields (e.g. sea surface height, or the Okubo-Weiss parameter) that satisfy geometric criteria and anomaly thresholds. In contrast, recent studies employ Lagrangian analysis of virtual particle trajectories initialized within the selected Eulerian contours, revealing significant discrepancies between the advection of the contour's material interior and the evolution of the Eulerian field contour. This work investigates the global mass and tracer transport associated with materially coherent surface ocean vortices. Further, it addresses differences between Eulerian and Lagrangian analyses for the detection of vortices. To do so, we use GFDL's CM2.6 coupled climate <span class="hlt">model</span> with 5-10km horizontal grid spacing. We identify coherent vortices in CM2.6 by implementing the Rotationally Coherent Lagrangian Vortex (RCLV) framework, which recently emerged from dynamical systems theory. This approach involves the numerical advection of millions of Lagrangian particles and guarantees material coherence by construction. We compute the statistics, spatial distribution, and lifetimes of coherent vortices in addition to calculating the associated mass and tracer transports. We offer compelling evidence that Eulerian vortex methods are poorly suited to answer questions of mass and tracer transport.</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><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('https://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="https://ntrs.nasa.gov/search.jsp?R=20020020656&hterms=statistics&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D70%26Ntt%3Dstatistics"><span>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('https://ntrs.nasa.gov/search.jsp?R=20020020656&hterms=climate+change+statistics&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D10%26Ntt%3Dclimate%2Bchange%2Bstatistics','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=20020020656&hterms=climate+change+statistics&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D10%26Ntt%3Dclimate%2Bchange%2Bstatistics"><span>Estimation of <span class="hlt">Mesoscale</span> Atmospheric Latent Heating Profiles from TRMM Rain Statistics Utilizing a Simple One-Dimensional <span class="hlt">Model</span></span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Iacovazzi, Robert A., Jr.; Prabhakara, C.; Lau, William K. M. (Technical Monitor)</p> <p>2001-01-01</p> <p>In this study, a <span class="hlt">model</span> is developed to estimate <span class="hlt">mesoscale</span>-resolution atmospheric latent heating (ALH) profiles. It utilizes rain statistics deduced from Tropical Rainfall Measuring Mission (TRMM) data, and cloud vertical velocity profiles and regional surface thermodynamic climatologies derived from other available data sources. From several rain events observed over tropical ocean and land, ALH profiles retrieved by this <span class="hlt">model</span> in convective rain regions reveal strong warming throughout most of the troposphere, while in stratiform rain regions they usually show slight cooling below the freezing level and significant warming above. The <span class="hlt">mesoscale</span>-average, or total, ALH profiles reveal a dominant stratiform character, because stratiform rain areas are usually much larger than convective rain areas. Sensitivity tests of the <span class="hlt">model</span> show that total ALH at a given tropospheric level varies by less than +/- 10 % when convective and stratiform rain rates and <span class="hlt">mesoscale</span> fractional rain areas are perturbed individually by 1 15 %. This is also found when the non-uniform convective vertical velocity profiles are replaced by one that is uniform. Larger variability of the total ALH profiles arises when climatological ocean- and land-surface temperatures (water vapor mixing ratios) are independently perturbed by +/- 1.0 K (+/- 5 %) and +/- 5.0 K (+/- 15 %), respectively. At a given tropospheric level, such perturbations can cause a +/- 25 % variation of total ALH over ocean, and a factor-of-two sensitivity over land. This sensitivity is reduced substantially if perturbations of surface thermodynamic variables do not change surface relative humidity, or are not extended throughout the entire <span class="hlt">model</span> evaporation layer. The ALH profiles retrieved in this study agree qualitatively with tropical total diabatic heating profiles deduced in earlier studies. Also, from January and July 1999 ALH-profile climatologies generated separately with TRMM Microwave Imager and Precipitation Radar rain</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2010JMEP...19...22G','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2010JMEP...19...22G"><span>Development of a <span class="hlt">Meso-Scale</span> Material <span class="hlt">Model</span> for Ballistic Fabric and Its Use in Flexible-Armor Protection Systems</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Grujicic, M.; Bell, W. C.; Arakere, G.; He, T.; Xie, X.; Cheeseman, B. A.</p> <p>2010-02-01</p> <p>A <span class="hlt">meso-scale</span> ballistic material <span class="hlt">model</span> for a prototypical plain-woven single-ply flexible armor is developed and implemented in a material user subroutine for the use in commercial explicit finite element programs. The main intent of the <span class="hlt">model</span> is to attain computational efficiency when calculating the mechanical response of the multi-ply fabric-based flexible-armor material during its impact with various projectiles without significantly sacrificing the key physical aspects of the fabric microstructure, architecture, and behavior. To validate the new <span class="hlt">model</span>, a comparative finite element method analysis is carried out in which: (a) the plain-woven single-ply fabric is <span class="hlt">modeled</span> using conventional shell elements and weaving is done in an explicit manner by snaking the yarns through the fabric and (b) the fabric is treated as a planar continuum surface composed of conventional shell elements to which the new <span class="hlt">meso-scale</span> unit-cell based material <span class="hlt">model</span> is assigned. The results obtained show that the material <span class="hlt">model</span> provides a reasonably good description for the fabric deformation and fracture behavior under different combinations of fixed and free boundary conditions. Finally, the <span class="hlt">model</span> is used in an investigation of the ability of a multi-ply soft-body armor vest to protect the wearer from impact by a 9-mm round nose projectile. The effects of inter-ply friction, projectile/yarn friction, and the far-field boundary conditions are revealed and the results explained using simple wave mechanics principles, high-deformation rate material behavior, and the role of various energy-absorbing mechanisms in the fabric-based armor systems.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017AIPC.1793c0025J','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017AIPC.1793c0025J"><span>Extending atomistic scale chemistry to <span class="hlt">mesoscale</span> <span class="hlt">model</span> of condensed-phase deflagration</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Joshi, Kaushik; Chaudhuri, Santanu</p> <p>2017-01-01</p> <p>Predictive simulations connecting chemistry that follow the shock or thermal initiation of energetic materials to subsequent deflagration or detonation events is currently outside the realm of possibilities. Molecular dynamics and first-principles based dynamics have made progress in understanding reactions in picosecond to nanosecond time scale. Results from thermal ignition of different phases of RDX show a complex reaction network and emergence of a deterministic behavior for critical temperature before ignition and hot spot growth rates. The kinetics observed is dependent on the hot spot temperature, system size and thermal conductivity. For cases where ignition is observed, the incubation period is dominated by intermolecular and intramolecular hydrogen transfer reactions. The gradual temperature and pressure increase in the incubation period is accompanied by accumulation of heavier polyradicals. The challenge of connecting such chemistry in <span class="hlt">mesoscale</span> simulations remain in reducing the complexity of chemistry. The hot spot growth kinetics in RDX grains and interfaces is an important challenge for reactive simulations aiming to fill in the gaps in our knowledge in the nanoseconds to microseconds time scale. The results discussed indicate that the <span class="hlt">mesoscale</span> chemistry may include large polyradical molecules in dense reactive mix reaching an instability point at certain temperatures and pressures.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/servlets/purl/10119533','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/servlets/purl/10119533"><span>An approach for parameterizing <span class="hlt">mesoscale</span> precipitating systems</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Weissbluth, M.J.; Cotton, W.R.</p> <p>1991-12-31</p> <p>A cumulus parameterization laboratory has been described which uses a reference numerical <span class="hlt">model</span> to fabricate, calibrate and verify a cumulus parameterization scheme suitable for use in <span class="hlt">mesoscale</span> <span class="hlt">models</span>. Key features of this scheme include resolution independence and the ability to provide hydrometeor source functions to the host <span class="hlt">model</span>. Thus far, only convective scale drafts have been parameterized, limiting the use of the scheme to those <span class="hlt">models</span> which can resolve the <span class="hlt">mesoscale</span> circulations. As it stands, the scheme could probably be incorporated into <span class="hlt">models</span> having a grid resolution greater than 50 km with results comparable to the existing schemes for the large-scale <span class="hlt">models</span>. We propose, however, to quantify the <span class="hlt">mesoscale</span> circulations through the use of the cumulus parameterization laboratory. The inclusion of these <span class="hlt">mesoscale</span> drafts in the existing scheme will hopefully allow the correct parameterization of the organized <span class="hlt">mesoscale</span> precipitating systems.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/servlets/purl/5750068','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/servlets/purl/5750068"><span>An approach for parameterizing <span class="hlt">mesoscale</span> precipitating systems</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Weissbluth, M.J.; Cotton, W.R.</p> <p>1991-01-01</p> <p>A cumulus parameterization laboratory has been described which uses a reference numerical <span class="hlt">model</span> to fabricate, calibrate and verify a cumulus parameterization scheme suitable for use in <span class="hlt">mesoscale</span> <span class="hlt">models</span>. Key features of this scheme include resolution independence and the ability to provide hydrometeor source functions to the host <span class="hlt">model</span>. Thus far, only convective scale drafts have been parameterized, limiting the use of the scheme to those <span class="hlt">models</span> which can resolve the <span class="hlt">mesoscale</span> circulations. As it stands, the scheme could probably be incorporated into <span class="hlt">models</span> having a grid resolution greater than 50 km with results comparable to the existing schemes for the large-scale <span class="hlt">models</span>. We propose, however, to quantify the <span class="hlt">mesoscale</span> circulations through the use of the cumulus parameterization laboratory. The inclusion of these <span class="hlt">mesoscale</span> drafts in the existing scheme will hopefully allow the correct parameterization of the organized <span class="hlt">mesoscale</span> precipitating systems.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/1420848','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/1420848"><span>Marginal <span class="hlt">models</span> for correlated binary responses with multiple classes and multiple levels of <span class="hlt">nesting</span>.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Qaqish, B F; Liang, K Y</p> <p>1992-09-01</p> <p>A <span class="hlt">model</span> for correlated binary data is presented. Marginal probabilities and odds ratios are allowed to have general regression structures that include multiple classes and multiple levels of <span class="hlt">nesting</span>. Estimation is done through the generalized estimating equations approach of Liang and Zeger (1986, Biometrika 73, 13-22). They are contrasted with conditional <span class="hlt">models</span> and recommendations for choosing between the two are given. Examples from genetic epidemiology are presented.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015EGUGA..1714285S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015EGUGA..1714285S"><span>Performance of MODIS satellite and <span class="hlt">mesoscale</span> <span class="hlt">model</span> based land surface temperature for soil moisture deficit estimation using Neural Network</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Srivastava, Prashant K.; Petropoulos, George P.; Gupta, Manika; Islam, Tanvir</p> <p>2015-04-01</p> <p>Soil Moisture Deficit (SMD) is a key variable in the water and energy exchanges that occur at the land-surface/atmosphere interface. Monitoring SMD is an alternate method of irrigation scheduling and represents the use of the suitable quantity of water at the proper time by combining measurements of soil moisture deficit. In past it is found that LST has a strong relation to SMD, which can be estimated by MODIS or numerical weather prediction <span class="hlt">model</span> such as WRF (Weather Research and Forecasting <span class="hlt">model</span>). By looking into the importance of SMD, this work focused on the application of Artificial Neural Network (ANN) for evaluating its capabilities towards SMD estimation using the LST data estimated from MODIS and WRF <span class="hlt">mesoscale</span> <span class="hlt">model</span>. The benchmark SMD estimated from Probability Distribution <span class="hlt">Model</span> (PDM) over the Brue catchment, Southwest of England, U.K. is used for all the calibration and validation experiments. The performances between observed and simulated SMD are assessed in terms of the Nash-Sutcliffe Efficiency (NSE), the Root Mean Square Error (RMSE) and the percentage of bias (%Bias). The application of the ANN confirmed a high capability WRF and MODIS LST for prediction of SMD. Performance during the ANN calibration and validation showed a good agreement between benchmark and estimated SMD with MODIS LST information with significantly higher performance than WRF simulated LST. The work presented showed the first comprehensive application of LST from MODIS and WRF <span class="hlt">mesoscale</span> <span class="hlt">model</span> for hydrological SMD estimation, particularly for the maritime climate. More studies in this direction are recommended to hydro-meteorological community, so that useful information will be accumulated in the technical literature domain for different geographical locations and climatic conditions. Keyword: WRF, Land Surface Temperature, MODIS satellite, Soil Moisture Deficit, Neural Network</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/19850016369','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19850016369"><span>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://adsabs.harvard.edu/abs/2014PhyA..416..518G','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014PhyA..416..518G"><span>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('https://www.ncbi.nlm.nih.gov/pubmed/24523891','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/24523891"><span>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 like