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Sample records for model mm5 grell

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

    Science.gov (United States)

    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.

  2. Study of tropical cyclone "Fanoos" using MM5 model – a case study

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    S. Ramalingeswara Rao

    2009-01-01

    Full Text Available Tropical cyclones are one of the most intense weather hazards over east coast of India and create a lot of devastation through gale winds and torrential floods while they cross the coast. So an attempt is made in this study to simulate track and intensity of tropical cyclone "Fanoos", which is formed over the Bay of Bengal during 5–10 December 2005 by using mesoscale model MM5. The simulated results are compared with the observed results of India Meteorological Department (IMD; results show that the cumulus parameterization scheme, Kain-Fritsch (KF is more accurately simulated both in track and intensity than the other Betts-Miller (BM and Grell Schemes. The reason for better performance of KF-1 scheme may be due to inclusion of updrafts and downdrafts. The model could predict the minimum Central Sea Level Pressure (CSLP as 983 hPa as compared to the IMD reports of 984 hPa and the wind speed is simulated at maximum 63 m/s compared to the IMD estimates of 65 m/s. Secondly "Fanoos" development from the lagrangian stand point in terms of vertical distribution of Potential Vorticity (PV is also carried out around cyclone centre.

  3. An evaporation duct prediction model coupled with the MM5

    Institute of Scientific and Technical Information of China (English)

    JIAO Lin; ZHANG Yonggang

    2015-01-01

    Evaporation duct is an abnormal refractive phenomenon in the marine atmosphere boundary layer. It has been generally accepted that the evaporation duct prominently affects the performance of the electronic equipment over the sea because of its wide distribution and frequent occurrence. It has become a research focus of the navies all over the world. At present, the diagnostic models of the evaporation duct are all based on the Monin-Obukhov similarity theory, with only differences in the flux and character scale calculations in the surface layer. These models are applicable to the stationary and uniform open sea areas without considering the alongshore effect. This paper introduces the nonlinear factorav and the gust wind itemwg into the Babin model, and thus extends the evaporation duct diagnostic model to the offshore area under extremely low wind speed. In addition, an evaporation duct prediction model is designed and coupled with the fifth generation mesoscale model (MM5). The tower observational data and radar data at the Pingtan island of Fujian Province on May 25–26, 2002 were used to validate the forecast results. The outputs of the prediction model agree with the observations from 0 to 48 h. The relative error of the predicted evaporation duct height is 19.3% and the prediction results are consistent with the radar detection.

  4. 2-way coupling the hydrological land surface model PROMET with the regional climate model MM5

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    F. Zabel

    2013-05-01

    Full Text Available Most land surface hydrological models (LSHMs consider land surface processes (e.g. soil–plant–atmosphere interactions, lateral water flows, snow and ice in a spatially detailed manner. The atmosphere is considered as exogenous driver, neglecting feedbacks between the land surface and the atmosphere. On the other hand, regional climate models (RCMs generally simulate land surface processes through coarse descriptions and spatial scales but include land–atmosphere interactions. What is the impact of the differently applied model physics and spatial resolution of LSHMs on the performance of RCMs? What feedback effects are induced by different land surface models? This study analyses the impact of replacing the land surface module (LSM within an RCM with a high resolution LSHM. A 2-way coupling approach was applied using the LSHM PROMET (1 × 1 km2 and the atmospheric part of the RCM MM5 (45 × 45 km2. The scaling interface SCALMET is used for down- and upscaling the linear and non-linear fluxes between the model scales. The change in the atmospheric response by MM5 using the LSHM is analysed, and its quality is compared to observations of temperature and precipitation for a 4 yr period from 1996 to 1999 for the Upper Danube catchment. By substituting the Noah-LSM with PROMET, simulated non-bias-corrected near-surface air temperature improves for annual, monthly and daily courses when compared to measurements from 277 meteorological weather stations within the Upper Danube catchment. The mean annual bias was improved from −0.85 to −0.13 K. In particular, the improved afternoon heating from May to September is caused by increased sensible heat flux and decreased latent heat flux as well as more incoming solar radiation in the fully coupled PROMET/MM5 in comparison to the NOAH/MM5 simulation. Triggered by the LSM replacement, precipitation overall is reduced; however simulated precipitation amounts are still of high uncertainty, both

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

    Energy Technology Data Exchange (ETDEWEB)

    Seaman, N.L.; Kain, J.S.; Deng, A. [Pennsylvania State Univ., University Park, PA (United States)

    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. The impact of MM5 and WRF meteorology over complex terrain on CHIMERE model calculations

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    A. de Meij

    2009-01-01

    Full Text Available The objective of this study is to evaluate the impact of meteorological input data on calculated gas and aerosol concentrations. We use two different meteorological models (MM5 and WRF together with the chemistry transport model CHIMERE. We focus on the Po valley area (Italy for January and June 2005.

    Firstly we evaluate the meteorological parameters with observations. The analysis shows that the performance of both models is similar, however some small differences are still noticeable.

    Secondly, we analyze the impact of using MM5 and WRF on calculated PM10 and O3 concentrations. In general CHIMERE/MM5 and CHIMERE/WRF underestimate the PM10 concentrations for January. The difference in PM10 concentrations for January between CHIMERE/MM5 and CHIMERE/WRF is around a factor 1.6 (PM10 higher for CHIMERE/MM5. This difference and the larger underestimation in PM10 concentrations by CHIMERE/WRF are related to the differences in heat fluxes and the resulting PBL heights calculated by WRF. In general the PBL height by WRF meteorology is a factor 2.8 higher at noon in January than calculated by MM5. This study showed that the difference in microphysics scheme has an impact on the profile of cloud liquid water (CLW calculated by the meteorological driver and therefore on the production of SO4 aerosol.

    A sensitivity analysis shows that changing the Noah Land Surface Model (LSM for the 5-layer soil temperature model, the calculated monthly mean PM10 concentrations increase by 30%, due to the change in the heat fluxes and the resulting PBL heights.

    For June, PM10 calculated concentrations by CHIMERE/MM5 and CHIMERE/WRF are similar and agree with the observations. Calculated O3 values for June are in general overestimated by a factor 1.3 by CHIMERE/MM5 and CHIMRE/WRF. The reason for this is that daytime NO2

  7. ASSIMILATION OF ALTIMETER WIND DATA IN MESOSCALE NUMERICAL MODEL (MM5)

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    Making use of altimeter wind data and standard sounding data in a mesoscale numerical model of PSU/NCAR (MM5), we test four-dimensional data assimilation scheme based on nudging. The purpose of this paper is to determine what meteorological fields and what assimilation method have positive effect on typhoon sea surface wind by simulating two typhoon cases in MM5. We perform seven experiments for 9608 Typhoon (Case 1): one control experiment, three analysis nudging experiments, two observation nudging experiments and one analysis and observation nudging experiment; we perform one control experiment and one analysis nudging experiment for 9711 Typhoon (Case 2). The results show assimilating wind-thermal fields can effectively improve simulation accuracy of the model; the experiment combining standard sounding data and surface observations can improve greatly the simulation accuracy of the model; the altimeter data contain lots of sea surface information and also have positive impact on typhoon sea surface wind.

  8. Application of MM5/CMAQ for modelling urban air pollution a case study for London, UK

    Science.gov (United States)

    Kitwiroon, N.; Fragkou, E.; Sokhi, R. S.; San Jose, R.; Pérez Camaño, J. L.; Middleton, D.

    2003-04-01

    Urban air pollution has been particularly studied for the last few decades because of its recognised environmental dangers and health implications. The complexity of the urban surface characteristics and turbulence patterns has dictated the use of numerical models by environmental research agencies and regulators in order to predict and manage urban air pollution. However, most of these models are not specifically adapted to urban applications and normally do not include detailed urban parameterisation, such as for surface roughness or urban heat fluxes. Flow structure and dispersion of air pollutants within cities, however, are influenced by urban features such as increased surface roughness. This paper presents a study using MM5 and CMAQ to assess the effect of urban boundary layer features on meteorological parameters, and hence London's air quality. MM5 is a non-hydrostatic (version 3), terrain-following sigma-coordinate model designed to simulate mesoscale and regional-scale atmospheric circulation. This paper employs an improved surface roughness treatment on meteorological profiles and pollution dispersion. A surface roughness scale has been developed for London and the surrounding region. The land cover data was derived from the Centre for Ecology and Hydrology (CEH) data, with a spatial resolution of 25 × 25 m. These z_o values are employed with MM5 for modelling meteorological parameters over London, covering an inner domain area of 49 × 49 km. The outputs of MM5 have been coupled to CMAQ photochemical model to predict concentrations of particles, NO_2 and O_3 for London and the surrounding regions at a spatial resolution of 1 × 1 km. The predicted concentrations have been compared with monitored data obtained from a range of national air quality monitoring sites including Central London (Bloomsbury, Brent), East London (Bexley) and West London (Hillingdon). Comparison of hourly model predictions with measured data is made for pollution levels for

  9. Regional climate simulations over South America: sensitivity to model physics and to the treatment of lateral boundary conditions using the MM5 model

    Energy Technology Data Exchange (ETDEWEB)

    Solman, Silvina A. [CONICET-UBA, Centro de Investigaciones del Mar y la Atmosfera (CIMA), Buenos Aires (Argentina); Universidad de Buenos Aires, Departamento de Ciencias de la Atmosfera y los Oceanos. Facultad de Ciencias Exactas y Naturales, Buenos Aires (Argentina); Pessacg, Natalia L. [CONICET-UBA, Centro de Investigaciones del Mar y la Atmosfera (CIMA), Buenos Aires (Argentina)

    2012-01-15

    In this study the capability of the MM5 model in simulating the main mode of intraseasonal variability during the warm season over South America is evaluated through a series of sensitivity experiments. Several 3-month simulations nested into ERA40 reanalysis were carried out using different cumulus schemes and planetary boundary layer schemes in an attempt to define the optimal combination of physical parameterizations for simulating alternating wet and dry conditions over La Plata Basin (LPB) and the South Atlantic Convergence Zone regions, respectively. The results were compared with different observational datasets and model evaluation was performed taking into account the spatial distribution of monthly precipitation and daily statistics of precipitation over the target regions. Though every experiment was able to capture the contrasting behavior of the precipitation during the simulated period, precipitation was largely underestimated particularly over the LPB region, mainly due to a misrepresentation in the moisture flux convergence. Experiments using grid nudging of the winds above the planetary boundary layer showed a better performance compared with those in which no constrains were imposed to the regional circulation within the model domain. Overall, no single experiment was found to perform the best over the entire domain and during the two contrasting months. The experiment that outperforms depends on the area of interest, being the simulation using the Grell (Kain-Fritsch) cumulus scheme in combination with the MRF planetary boundary layer scheme more adequate for subtropical (tropical) latitudes. The ensemble of the sensitivity experiments showed a better performance compared with any individual experiment. (orig.)

  10. Simulation of hailstorm event using Mesoscale Model MM5 with modified cloud microphysics scheme

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    P. Chatterjee

    2008-11-01

    Full Text Available Mesoscale model MM5 (Version 3.5 with some modifications in the cloud microphysics scheme of Schultz (1995, has been used to simulate two hailstorm events over Gangetic Plain of West Bengal, India. While the first event occurred on 12 March 2003 and the hails covered four districts of the state of West Bengal, India, the second hailstorm event struck Srinikatan (22.65° N, 87.7° E on 10 April 2006 at 11:32 UT and it lasted for 2–3 min. Both these events can be simulated, if the same modifications are introduced in the cloud microphysics scheme of Schultz. However, the original scheme of Schultz cannot simulate any hail.

    The results of simulation were compared with the necessary products of Doppler Weather Radar (DWR located at Kolkata (22.57° N, 88.35° E. Model products like reflectivity, graupel and horizontal wind are compared with the corresponding products of DWR. The pattern of hail development bears good similarity between model output and observation from DWR, if necessary modifications are introduced in the model. The model output of 24 h accumulated rain from 03:00 UT to next day 03:00 UT has also been compared with the corresponding product of the satellite TRMM.

  11. Simulation of High Impact Rainfall Events Over Southeastern Hilly Region of Bangladesh Using MM5 Model

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    M. N. Ahasan

    2013-01-01

    Full Text Available Simulation of high impact rainfall events over southeastern hilly region of Bangladesh has been carried out using Fifth-Generation PSU/NCAR Mesoscale Model (MM5 conducting two historical rainfall events, namely, 21 June, 2004 and 11 July, 2004. These extraordinary rainfall events were localized over the Rangamati region and recorded 304 mm and 337 mm rainfall on 21 June, 2004 and 11 July, 2004, respectively, over Rangamati within a span of 24 h. The model performance was evaluated by examining the different predicted and derived parameters. It is found that the seasonal monsoon trough has northerly position compared to normal and pass through Bangladesh extending up to northeast India for both cases. The heat low was found to be intense (996 hPa with strong north-south pressure gradient (12–15 hPa. The analysis of the geopotential height field at 200 hPa shows that the Tibetan high is shifted towards south by 7-8° latitudes with axis along 22–25°N for both cases. The analysis of the wind field shows that the areas of high impact rainfall exhibit strong convergence of low level monsoon circulation (~19–58 knots. The strong southwesterlies were found to exist up to 500 hPa level in both cases. The lower troposphere (925–500 hPa was characterized by the strong vertical wind shear (~9–18 ms−1 and high relative vorticity (~20–40 × 10−5 s−1. The analysis also shows that the areas of high impact rainfall events and neighbourhoods are characterized by strong low level convergence and upper level divergence. The strong southwesterly flow causes transportation of large amount of moisture from the Bay of Bengal towards Bangladesh, especially over the areas of Rangamati and neighbourhoods. The high percentage of relative humidity extends up to the upper troposphere along a narrow vertical column. Model produced details structure of the spatial patterns of rainfall over Bangladesh reasonably well though there are some

  12. A Comparison Of Primitive Model Results Of The Short Term Wind Energy Prediction System (Sweps): WRF vs MM5

    Science.gov (United States)

    Unal, E.; Tan, E.; Mentes, S. S.; Caglar, F.; Turkmen, M.; Unal, Y. S.; Onol, B.; Ozdemir, E. T.

    2012-04-01

    Although discontinuous behavior of wind field makes energy production more difficult, wind energy is the fastest growing renewable energy sector in Turkey which is the 6th largest electricity market in Europe. Short-term prediction systems, which capture the dynamical and statistical nature of the wind field in spatial and time scales, need to be advanced in order to increase the wind power prediction accuracy by using appropriate numerical weather forecast models. Therefore, in this study, performances of the next generation mesoscale Numerical Weather Forecasting model, WRF, and The Fifth-Generation NCAR/Penn State Mesoscale Model, MM5, have been compared for the Western Part of Turkey. MM5 has been widely used by Turkish State Meteorological Service from which MM5 results were also obtained. Two wind farms of the West Turkey have been analyzed for the model comparisons by using two different model domain structures. Each model domain has been constructed by 3 nested domains downscaling from 9km to 1km resolution by the ratio of 3. Since WRF and MM5 models have no exactly common boundary layer, cumulus, and microphysics schemes, the similar physics schemes have been chosen for these two models in order to have reasonable comparisons. The preliminary results show us that, depending on the location of the wind farms, MM5 wind speed RMSE values are 1 to 2 m/s greater than that of WRF values. Since 1 to 2 m/s errors can be amplified when wind speed is converted to wind power; it is decided that the WRF model results are going to be used for the rest of the project.

  13. A numerical study of cell merger over Cuba - Part I: implementation of the ARPS/MM5 models

    Science.gov (United States)

    Pozo, D.; Borrajero, I.; Marín, J. C.; Raga, G. B.

    2006-11-01

    On 21 July 2001 a number of severe storms developed over the region of Camaguey, Cuba, which were observed by radar. A numerical simulation was performed in order to realistically reproduce the development of the storms observed that day. The mesoscale model MM5 was used to determine the initial, boundary and update conditions for the storm-scale simulation with the model ARPS. Changes to the source code of ARPS were made in order to assimilate the output from the MM5 as input data and a new land-use file with a 1-km horizontal resolution for the Cuban territory was created. A case representing the merger between cells at different stages of development was correctly reproduced by the simulation and is in good agreement with radar observations. The state of development of each cell, the time when the merger occurred, starting from the formation of clouds, the propagation motion of the cells and the increase in precipitation, due to the growth of the area after the merger, were correctly reproduced. Simulated clouds matched the main characteristics of the observed radar echoes, though in some cases, reflectivity tops and horizontal areas were overestimated. Maximum reflectivity values and the heights where these maximum values were located were in good agreement with radar data, particularly when the model reflectivity was calculated without including the snow. The MM5/ARPS configuration introduced in this study, improved sensibly the ability to simulate convective systems, thereby enhancing the local forecasting of convection in the region.

  14. High-resolution modeling and evaluation of ozone air quality of Osaka using an MM5-CMAQ system

    Institute of Scientific and Technical Information of China (English)

    SHRESTHA Kundan Lal; KONDO Akira; KAGA Akikazu; INOUE Yoshio

    2009-01-01

    High-resolution modeling approach is increasingly being considered as a necessary step for improving the monitoring and predictions of regional air quality.This is especially true for highly urbanized region with complex terrain and land-use.This study uses Community Multiscale Air Quality (CMAQ) model coupled with MM5 mesoscale model for a comprehensive analysis to assess the suitability of such high-resolution modeling system in predicting ozone air quality in the complex terrains of Osaka,Japan.The 1-km and 3-km grid domains were nested inside a 9-km domain and the domain with 1-km grid covered the Osaka region.High-resolution Grid Point Value-Mesoscale Model μgPV-MSM) data were used after suitable validation.The simulated ozone concentrations were validated and evaluated using statistical metrics using performance criteria set for ozone.Daily maxima of ozone were found better simulated by the 1-km grid domain than the coarser 9-km and 3-km domains,with the maximum improvement in the mean absolute gross error about 3 ppbv.In addition,1-km grid results fared better than other grids at most of the observation stations that showed noticeable differences in gross error as well as correlation.These results amply justify the use of the integrated high-resolution MM5-CMAQ modeling system in the highly urbanized region,such as the Osaka region,which has complex terrain and land-use.

  15. A numerical study of cell merger over Cuba – Part I: implementation of the ARPS/MM5 models

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    G. B. Raga

    2006-11-01

    Full Text Available On 21 July 2001 a number of severe storms developed over the region of Camaguey, Cuba, which were observed by radar. A numerical simulation was performed in order to realistically reproduce the development of the storms observed that day. The mesoscale model MM5 was used to determine the initial, boundary and update conditions for the storm-scale simulation with the model ARPS. Changes to the source code of ARPS were made in order to assimilate the output from the MM5 as input data and a new land-use file with a 1-km horizontal resolution for the Cuban territory was created. A case representing the merger between cells at different stages of development was correctly reproduced by the simulation and is in good agreement with radar observations. The state of development of each cell, the time when the merger occurred, starting from the formation of clouds, the propagation motion of the cells and the increase in precipitation, due to the growth of the area after the merger, were correctly reproduced. Simulated clouds matched the main characteristics of the observed radar echoes, though in some cases, reflectivity tops and horizontal areas were overestimated. Maximum reflectivity values and the heights where these maximum values were located were in good agreement with radar data, particularly when the model reflectivity was calculated without including the snow. The MM5/ARPS configuration introduced in this study, improved sensibly the ability to simulate convective systems, thereby enhancing the local forecasting of convection in the region.

  16. A performance evaluation of MM5/MNEQA/CMAQ air quality modelling system to forecast ozone concentrations in Catalonia

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    R. Arasa

    2010-01-01

    Full Text Available We examine the ability of a modelling system to forecast the formation and transport of ozone over Catalonia, at the NE of the Iberian Peninsula. To this end, the Community Multiscale Air Quality (CMAQ modelling system developed by the United States Environmental Protection Agency (US EPA and the PSU/NCAR mesoscale modelling system MM5 are coupled to a new emission model, the Numerical Emission Model for Air Quality (MNEQA. The outputs of the modelling system for the period from May to October 2008 are compared with ozone measurements at selected air-monitoring stations belonging to the Catalan Government. Results indicate a good behaviour of the model in reproducing diurnal ozone concentrations, as statistical values fall within the EPA and EU regulatory frameworks.

  17. A numerical study of summer ozone concentration over the Kanto area of Japan using the MM5/CMAQ model

    Institute of Scientific and Technical Information of China (English)

    Mai Khiem; Ryozo Ooka; Hong Huang; Hiroshi Hayami

    2011-01-01

    We assessed the ability of the MM5/CMAQ model to predict ozone (O3) air quality over the Kanto area and to investigate the factors that affect simulation of O3. We find that the coupled MM5/CMAQ model is a useful tool for the analysis of urban environmental problems. The simulation results were compared with observational data and were found to accurately replicate most of the important observed characteristics. The initial and boundary conditions were found to have a significant effect on simulated O3 concentrations.The results show that on hot and dry days with high O3 concentration, the CMAQ model provides a poor simulation of O3 maxima when using initial and boundary conditions derived from the CMAQ default data. The simulation of peak O3 concentrations is improved with the JCAP initial and boundary conditions. On mild days, the default CMAQ initial and boundary conditions provide a more realistic simulation. Meteorological conditions also have a strong impact on the simulated distribution and accumulation of O3 concentrations in this area. Low O3 concentrations are simulated during mild weather conditions, and high concentrations are predicted during hot and dry weather. By investigating the effects of different meteorological conditions on each model process, we find that advection and diffusion differ the most between the two meteorological regimes. Thus, differences in the winds that govern the transport of O3 and its precursors are likely the most important meteorological drivers of ozone concentration over the central Kanto area.

  18. MM5模式在大连近海风资源评估中的应用%Application of MM5 model in the assessment on offshore wind resource in Dalian

    Institute of Scientific and Technical Information of China (English)

    任年鑫; 孙英伟; 欧进萍

    2011-01-01

    利用中尺度MM5气象模式系统,对大连及其近海地区风场进行了较为系统的高分辨率数值模拟.定性及定量地得到了该地区IOM高度处的年平均风速等直线图、年有效风能小时数等值线图、年有效风能功率等值线图及长海地区的年风玫瑰图,进一步研究了该地区年有效风能功率密度沿垂直高度的变化.综合考虑该地区沿海水深、港口运输及水产养殖等因素的影响,建设性地提出了3个近海风能重点开发区域,并给出了这3个地区的年风速分布概率情况.基于MM5模式的数值评估结果,为该地区近海风资源的开发利用提供了重要的参考依据.%The sophisticated non-hydrostatic Mesoscale meteorology MM5 Model has been applied to high-resolution numerical simulation of wind fields in Dalian coastal zone. The annual average wind speed contour map, the annual available wind hourly contour map, the available wind energy density contour map and the wind rose map have been qualitatively and quantitatively obtained for Dalian. Furthermore, the effect of the different vertical heights on the wind energy power density has been studied.Taking the factors of water depth, port transportation and aquafarm into consideration, three key wind energy exploitation zones are proposed and the wind speed distribution probabilities for these places are given. In general, the high-resolution numerical results from MM5 model may effectively provide an important scientific basis for the exploitation of the offshore wind energy in Dalian.

  19. Selecting optimal monitoring site locations for peak ambient particulate material concentrations using the MM5-CAMx4 numerical modelling system.

    Science.gov (United States)

    Sturman, Andrew; Titov, Mikhail; Zawar-Reza, Peyman

    2011-01-15

    Installation of temporary or long term monitoring sites is expensive, so it is important to rationally identify potential locations that will achieve the requirements of regional air quality management strategies. A simple, but effective, numerical approach to selecting ambient particulate matter (PM) monitoring site locations has therefore been developed using the MM5-CAMx4 air pollution dispersion modelling system. A new method, 'site efficiency,' was developed to assess the ability of any monitoring site to provide peak ambient air pollution concentrations that are representative of the urban area. 'Site efficiency' varies from 0 to 100%, with the latter representing the most representative site location for monitoring peak PM concentrations. Four heavy pollution episodes in Christchurch (New Zealand) during winter 2005, representing 4 different aerosol dispersion patterns, were used to develop and test this site assessment technique. Evaluation of the efficiency of monitoring sites was undertaken for night and morning aerosol peaks for 4 different particulate material (PM) spatial patterns. The results demonstrate that the existing long term monitoring site at Coles Place is quite well located, with a site efficiency value of 57.8%. A temporary ambient PM monitoring site (operating during winter 2006) showed a lower ability to capture night and morning peak aerosol concentrations. Evaluation of multiple site locations used during an extensive field campaign in Christchurch (New Zealand) in 2000 indicated that the maximum efficiency achieved by any site in the city would be 60-65%, while the efficiency of a virtual background site is calculated to be about 7%. This method of assessing the appropriateness of any potential monitoring site can be used to optimize monitoring site locations for any air pollution measurement programme.

  20. Some Study on Application of OpenMP in Mesoscale Meteorological Model-MM5%OpenMP在MM5中尺度模式中的应用试验

    Institute of Scientific and Technical Information of China (English)

    张昕; 季仲贞; 王斌

    2001-01-01

    A new parallel programming standard-OpenMP is introduced in the beginning of this article. Its advantage and disadvantage are known through comparison with some other parallel programming standards. The application of OpenMP in MM5 of PSU/NCAR is presented in detail. The parallel performance of both OpenMP and MPI have been tested on SGI Origin 2000. The result show that OpenMP is a simple and efficient parallel programming standard and especially suitable for meteorological sciences field.%简要介绍了一种新的并行编程标准——OpenMP通过与其他几种并行编程标准的比较,了解其优越与不足之处。详细介绍了OpenMP在PSU/NCAR的中尺度模式MM5中的运用。分别用OpenMP并行方式与MPI并行方式在SGIOrigin 2000上进行了并行效能测试。测试结果表明:OpenMP是一种简单、高效的并行编程标准,非常适合于气象科研与业务领域应用。

  1. Simulation of coastal winds along the central west coast of India using the MM5 mesoscale model

    Digital Repository Service at National Institute of Oceanography (India)

    Pushpadas, D.; Vethamony, P.; Sudheesh, K.; George, S.; Babu, M.T.; Nair, T.M.B.

    winds, sea level pressure, surface pressure, temperature, specific humidity, geopotential height, soil moisture, soil temperature, sea surface temperature, skin temperature, precipitable water, etc. The model is initialized at 0000 UTC on each...

  2. Development and optimization of the IPM MM5 GPS slant path 4DVAR system

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    Florian Zus

    2008-12-01

    Full Text Available This article describes the development of tools for routine 4-dimensional variational data assimilation of Global Positioning System Slant Total Delay (STD data in the framework of the MM5 system at the Institute of Physics and Meteorology of the University of Hohenheim. The Slant Total Delay forward operator is introduced which allows model validation and the assimilation in the Message-Passing Interface environment. An experiment is conducted which highlights the importance of accurate model physics in the variational assimilation system. We demonstrate that the model minus observation statistics of STD data crucially depends on the convection scheme and the implementation of horizontal diffusion. A set of modifications to the existing non linear, tangent linear and adjoint model is presented. These include an improvement of the horizontal diffusion scheme and the implementation of the Grell cumulus convective scheme in order to eliminate the observed systematic tendency in the model minus observation statistics of the STD data and precipitation in mountainous terrain. A first assimilation experiment with the improved MM5 variational assimilation system shows promising results.

  3. Evaluating the performance of an integrated CALPUFF-MM5 modeling system for predicting SO{sub 2} emission from a refinery

    Energy Technology Data Exchange (ETDEWEB)

    Abdul-Wahab, Sabah Ahmed [Sultan Qaboos University, Department of Mechanical and Industrial Engineering, College of Engineering, Muscat (Oman); Ali, Sappurd [National Engineering and Scientific Commission (NESCOM), Islamabad (Pakistan); Sardar, Sabir; Irfan, Naseem [Pakistan Institute of Engineering and Applied Sciences (PIEAS), Islamabad (Pakistan); Al-Damkhi, Ali [Public Authority for Applied Education and Training (PAAET), Department of Environmental Sciences College of Health Sciences, Salmiyah (Kuwait)

    2011-12-15

    Oil refineries are one of the proven sources of environmental pollution as they emit more than 100 chemicals into the atmosphere including sulfur dioxide (SO{sub 2}). The dispersion patterns of SO{sub 2} from emissions of Sohar refinery was simulated by employing California Puff (CALPUFF) model integrated with state of the art meteorological Mesoscale Model (MM5). The results of this simulation were used to quantify the ground level concentrations of SO{sub 2} in and around the refinery. The evaluation of the CALPUFF and MM5 modeling system was carried out by comparing the estimated results with that of observed data of the same area. The predicted concentrations of SO{sub 2} agreed well with the observed data, with minor differences in magnitudes. In addition, the ambient air quality of the area was checked by comparing the model results with the regulatory limits for SO{sub 2} set by the Ministry of Environment and Climate Affairs (MECA) in Oman. From the analysis of results, it was found that the concentration of SO{sub 2} in the nearby communities of Sohar refinery is well within the regulatory limits specified by MECA. Based on these results, it was concluded that no health risk, due to SO{sub 2} emissions, is present in areas adjacent to the refinery. (orig.)

  4. Evaluating the influence of antecedent soil moisture on variability of the North American Monsoon precipitation in the coupled MM5/VIC modeling system

    Directory of Open Access Journals (Sweden)

    Dennis P. Lettenmaier

    2009-11-01

    Full Text Available The influence of antecedent soil moisture on North American monsoon system (NAMS precipitation variability was explored using the MM5 mesoscale model coupled with the Variable Infiltration Capacity (VIC land surface model. Sensitivity experiments were performed with extreme wet and dry initial soil moisture conditions for both the 1984 wet monsoon year and the 1989 dry year. The MM5-VIC model reproduced the key features of NAMS in 1984 and 1989 especially over northwestern Mexico. Our modeling results indicate that the land surface has memory of the initial soil wetness prescribed at the onset of the monsoon that persists over most of the region well into the monsoon season (e.g. until August. However, in contrast to the classical thermal contrast concept, where wetter soils lead to cooler surface temperatures, less land-sea thermal contrast, weaker monsoon circulations and less precipitation, the coupled model consistently demonstrated a positive soil moisture – precipitation feedback. Specifically, anomalously wet pre-monsoon soil moisture always lead to enhanced monsoon precipitation, and the reverse was also true. Both the large-scale circulation change and local land-atmospheric interactions in response to pre-monsoon soil moisture anomalies play important roles in the coupled model’s positive soil moisture – monsoon precipitation feedback. However, the former may be sensitive to the strength and location of the thermal anomalies, thus leaving open the possibility of both positive and negative soil moisture – precipitation feedbacks. Furthermore, our use of a regional model with prescribed large-scale circulation at the model boundaries leaves open the possibility that the model behavior may, to some extent, reflect its limited ability to adjust its large-scale circulation to the regional thermal changes.

  5. Application of MM5-CAMx-PSAT Modeling Approach for Investigating Emission Source Contribution to Atmospheric SO2 Pollution in Tangshan, Northern China

    Directory of Open Access Journals (Sweden)

    Li Li

    2013-01-01

    Full Text Available The MM5-CMAx-PSAT modeling approach was presented to identify the variation of emission contribution from each modeling grid to regional and urban air quality per unit emission rate change. The method was applied to a case study in Tangshan Municipality, a typical industrial region in northern China. The variation of emission contribution to the monthly atmospheric SO2 concentrations in Tangshan from each modeling grid of 9 × 9 km per 1000 t/yr of emission rate change was simulated for four representative months in 2006. It was found that the northwestern part of Tangshan region had the maximum contribution variation ratio (i.e., greater than 0.36% to regional air quality, while the lowest contribution variation ratio (i.e., less than 0.3% occurred in the coastal areas. Principal component analysis (PCA, canonical correlation analysis (CCA, and Pearson correlation analysis indicated that there was an obvious negative correlation between the grid-based variation of emission contribution to regional air quality and planetary boundary layer height (PBLH as well as wind speed, while terrain data presented insignificant impacts on emission contribution variation. The proposed method was also applied to analyze the variation of emission contribution to the urban air quality of Tangshan (i.e., a smaller scale.

  6. The Same-Source Parallel MM5

    Directory of Open Access Journals (Sweden)

    John Michalakes

    2000-01-01

    Full Text Available Beginning with the March 1998 release of the Penn State University/NCAR Mesoscale Model (MM5, and continuing through eight subsequent releases up to the present, the official version has run on distributed -memory (DM parallel computers. Source translation and runtime library support minimize the impact of parallelization on the original model source code, with the result that the majority of code is line-for-line identical with the original version. Parallel performance and scaling are equivalent to earlier, hand-parallelized versions; the modifications have no effect when the code is compiled and run without the DM option. Supported computers include the IBM SP, Cray T3E, Fujitsu VPP, Compaq Alpha clusters, and clusters of PCs (so-called Beowulf clusters. The approach also is compatible with shared-memory parallel directives, allowing distributed-memory/shared-memory hybrid parallelization on distributed-memory clusters of symmetric multiprocessors.

  7. MM5 v3.6.1 and WRF v3.5.1 model comparison of standard and surface energy variables in the development of the planetary boundary layer

    Science.gov (United States)

    Wilmot, C.-S. M.; Rappenglück, B.; Li, X.; Cuchiara, G.

    2014-11-01

    Air quality forecasting requires atmospheric weather models to generate accurate meteorological conditions, one of which is the development of the planetary boundary layer (PBL). An important contributor to the development of the PBL is the land-air exchange captured in the energy budget as well as turbulence parameters. Standard and surface energy variables were modeled using the fifth-generation Penn State/National Center for Atmospheric Research mesoscale model (MM5), version 3.6.1, and the Weather Research and Forecasting (WRF) model, version 3.5.1, and compared to measurements for a southeastern Texas coastal region. The study period was 28 August-1 September 2006. It also included a frontal passage. The results of the study are ambiguous. Although WRF does not perform as well as MM5 in predicting PBL heights, it better simulates energy budget and most of the general variables. Both models overestimate incoming solar radiation, which implies a surplus of energy that could be redistributed in either the partitioning of the surface energy variables or in some other aspect of the meteorological modeling not examined here. The MM5 model consistently had much drier conditions than the WRF model, which could lead to more energy available to other parts of the meteorological system. On the clearest day of the study period, MM5 had increased latent heat flux, which could lead to higher evaporation rates and lower moisture in the model. However, this latent heat disparity between the two models is not visible during any other part of the study. The observed frontal passage affected the performance of most of the variables, including the radiation, flux, and turbulence variables, at times creating dramatic differences in the r2 values.

  8. MM5 v3.6.1 and WRF v3.2.1 model comparison of standard and surface energy variables in the development of the planetary boundary layer

    Science.gov (United States)

    Wilmot, C.-S. M.; Rappenglück, B.; Li, X.

    2014-04-01

    Air quality forecasting requires atmospheric weather models to generate accurate meteorological conditions, one of which is the development of the planetary boundary layer (PBL). An important contributor to the development of the PBL is the land-air exchange captured in the energy budget as well as turbulence parameters. Standard and surface energy variables were modeled using the fifth-generation Penn State/National Center for Atmospheric Research mesoscale model (MM5), version 3.6.1, and the Weather Research and Forecasting (WRF) model, version 3.2.1, and compared to measurements for a southeastern Texas coastal region. The study period was 28 August-1 September 2006. It also included a frontal passage. The results of the study are ambiguous. Although WRF does not perform as well as MM5 in predicting PBL heights, it better simulates most of the general and energy budget variables. Both models overestimate incoming solar radiation, which implies a surplus of energy that could be redistributed in either the partitioning of the surface energy variables or in some other aspect of the meteorological modeling not examined here. The MM5 model consistently had much drier conditions than the WRF model, which could lead to more energy available to other parts of the meteorological system. On the clearest day of the study period MM5 had increased latent heat flux, which could lead to higher evaporation rates and lower moisture in the model. However, this latent heat disparity between the two models is not visible during any other part of the study. The observed frontal passage affected the performance of most of the variables, including the radiation, flux, and turbulence variables, at times creating dramatic differences in the r2 values.

  9. Numerical simulation for a pollution weather process in Shenyang,Liaoning province using MM5 model and NCEP/NCAR data%利用MM5模式及NCEP资料对沈阳一次污染天气的数值模拟

    Institute of Scientific and Technical Information of China (English)

    邹旭东; 杨洪斌; 李帅彬; 刘玉彻; 汪宏宇

    2012-01-01

    利用NCEP/NCAR再分析资料和中尺度天气模式MM5对2010年1月14—19日沈阳大气污染天气系统进行模拟分析。对此次天气过程的地面和高空气压场、地面至高空各高度层随时间变化的水平风场及垂直剖面风场、垂直方向温度廓线等气象要素进行分析和模拟,描述大气污染中天气系统的变化过程,分析造成大气污染的气象要素变化。结果表明:此次污染天气过程对应地面场为长白山高压、地形槽环流型;500 hPa高空天气形势为两槽一脊,地面风场主要受高压辐散气流控制;地面至高空不同高度的水平风场均有偏南风切变和偏西风切变,垂直剖面风场对应有下沉气流,地面至高空的温度廓线出现明显的逆温。这些气象条件共同造成了持续污染天气。而500 hPa位势高度场持续长时间两槽一脊的环流形势,是造成长时间污染天气的主要原因。%Based on the NCEP/NCAR reanalysis data and the meso-scale weather model MM5,a pollution weather process in Shenyang from 14-19 January 2010 was simulated.Some meteorological elements were analyzed and simulated and these include the ground and upper air pressure fields,the horizontal and vertical wind fields from the ground to the upper level as well as their variation with time,and the vertical temperature profile etc..The variation of weather system was described in this process,and the meteorological elements causing atmospheric pollution were analyzed.The results indicate that the corresponding ground filed in this process is the Changbai Mountain high pressure and topographic trough circulation type.The upper weather situation is two troughs and one ridge at 500 hPa.The ground wind field is controlled by high pressure divergence airflow.The horizontal wind fields from the ground to the upper all have the southerly wind shear and westerly wind shear,and there is the corresponding downdraft in the vertical wind field

  10. Comparison of Observed, MM5 and WRF-NMM Model-Simulated, and HPAC-Assumed Boundary-Layer Meteorological Variables for 3 Days During the IHOP Field Experiment

    Science.gov (United States)

    Hanna, Steven R.; Reen, Brian; Hendrick, Elizabeth; Santos, Lynne; Stauffer, David; Deng, Aijun; McQueen, Jeffrey; Tsidulko, Marina; Janjic, Zavisa; Jovic, Dusan; Sykes, R. Ian

    2010-02-01

    The objective of the study is to evaluate operational mesoscale meteorological model atmospheric boundary-layer (ABL) outputs for use in the Hazard Prediction Assessment Capability (HPAC)/Second-Order Closure Integrated Puff (SCIPUFF) transport and dispersion model. HPAC uses the meteorological models’ routine simulations of surface buoyancy flux, winds, and mixing depth to derive the profiles of ABL turbulence. The Fifth-Generation Pennsylvania State University/National Center for Atmospheric Research Mesoscale Model (MM5) and the Weather Research and Forecast-Nonhydrostatic Mesoscale Model (WRF-NMM) ABL outputs and the HPAC ABL parameterisations are compared with observations during the International H2O Project (IHOP). The meteorological models’ configurations are not specially designed research versions for this study but rather are intended to be representative of what may be used operationally and thus have relatively coarse lowest vertical layer thicknesses of 59 and 36 m, respectively. The meteorological models’ simulations of mixing depth are in good agreement (±20%) with observations on most afternoons. Wind speed errors of 1 or 2 ms-1 are found, typical of those found in other studies, with larger errors occurring when the simulated centre of a low-pressure system is misplaced in time or space. The hourly variation of turbulent kinetic energy (TKE) is well-simulated during the daytime, although there is a meteorological model underprediction bias of about 20-40%. At night, WRF-NMM shows fair agreement with observations, and MM5 sometimes produces a very small default TKE value because of the stable boundary-layer parameterisation that is used. The HPAC TKE parameterisation is usually a factor of 5-10 high at night, primarily due to the fact that the meteorological model wind-speed output is at a height of 30 m for MM5 and 18 m for WRF-NMM, which is often well above the stable mixing depth. It is concluded that, before meteorological model TKE

  11. Evaluation of Interregional Transport Using the MM5 SCIPUFF System.

    Science.gov (United States)

    Deng, Aijun; Seaman, Nelson L.; Hunter, Glenn K.; Stauffer, David R.

    2004-12-01

    Improved understanding of transport issues and source receptor relationships on the interregional scale is dependent on reducing the uncertainties in the ability to define complex three-dimensional wind fields evolving in time. The numerical models used for this purpose have been upgraded substantially in recent years by introducing finer grid resolution, better representation of subgrid-scale physics, and practical four-dimensional data assimilation (FDDA) techniques that reduce the accumulation of errors over time. The impact of these improvements for interregional transport is investigated in this paper using the fifth-generation Pennsylvania State University National Center for Atmospheric Research Mesoscale Model (MM5) and the Second-Order Closure Integrated Puff (SCIPUFF) dispersion model to simulate the 1983 Cross-Appalachian Tracer Experiment (CAPTEX-83) episode 1 of 18 19 September 1983. Combining MM5 and SCIPUFF makes it possible to verify predicted tracer concentrations against observed surface concentrations collected during the CAPTEX-83 study. Conclusions from this study are as follows. 1) Not surprisingly, a baseline model configuration reflecting typical capabilities of the late 1980s (70-km horizontal grid, 15 vertical layers, older subgrid physics, and no FDDA) produced large meteorological errors that severely degraded the accuracy of the surface tracer concentrations predicted by SCIPUFF. 2) Improving the horizontal and vertical resolution of the MM5 to 12 km (typical for current operational model) and 32 layers led to some improvements in the statistical skill, but the further addition of more advanced physics produced much greater reductions of simulation errors. 3) The use of FDDA, along with 12-km resolution and improved physics, produced the overall best performance. 4) Further reduction of the horizontal grid size to 4 km had a detrimental effect on meteorological and plume-dispersion solutions in this case because of misrepresentation of

  12. Parallel implementation, validation, and performance of MM5

    Energy Technology Data Exchange (ETDEWEB)

    Michalakes, J.; Canfield, T.; Nanjundiah, R.; Hammond, S. [Argonne National Lab., IL (United States); Grell, G. [National Oceanic and Atmospheric Administration, Boulder, CO (United States)

    1994-12-31

    We describe a parallel implementation of the nonhydrostatic version of the Penn State/NCAR Mesoscale Model, MM5, that includes nesting capabilities. This version of the model can run on many different massively Parallel computers (including a cluster of workstations). The model has been implemented and run on the IBM SP and Intel multiprocessors using a columnwise decomposition that supports irregularly shaped allocations of the problem to processors. This stategy will facilitate dynamic load balancing for improved parallel efficiency and promotes a modular design that simplifies the nesting problem AU data communication for finite differencing, inter-domain exchange of data, and I/O is encapsulated within a parallel library, RSL. Hence, there are no sends or receives in the parallel model itself. The library is Generalizable to other, similar finite difference approximation codes. The code is validated by comparing the rate of growth in error between the sequential and parallel models with the error growth rate when the sequential model input is perturbed to simulate floating point rounding error. Series of runs on increasing numbers of parallel processors demonstrate that the parallel implementation is efficient and scalable to large numbers of processors.

  13. [Degradation of oil derivatives by Acinetobacter calcoaceticus MM5].

    Science.gov (United States)

    Marín, M M; Ortiz, M L; Laborda, F

    1994-01-01

    This paper describes the isolation of microorganisms from polluted heating oil. The growth of one of them has been studied (Acinetobacter calcoaceticus MM5) in several linear and branched hydrocarbons as well as the effect of its growth on commercial diesel oil. Acinetobacter calcoaceticus MM5 is not capable of using glucose as its only source of carbon, and it needs the presence of nitrogen and phosphorus sources to degrade any petroleum by-product.

  14. Validation of the Polar MM5 for Use in the Simulation of the Arctic River Basins

    Institute of Scientific and Technical Information of China (English)

    MA Yan; CHEN Shang

    2007-01-01

    The simulations were performed using a modified mesoscale model, the Polar MM5, which was adapted for use within polar regions. The objective of the study was to illustrate the skill of the Polar MM5 in simulating atmospheric behavior over the Arctic river basins. Automatic weather station data, global atmospheric analyses, as well as near-surface and upper-air observations were used to verify the simulation.Parallel simulations of the Polar MM5 and the original MM5 within the period 19-29 April 1997 simulations revealed that Polar MM5 reproduced better near-surface variables forecasts than the original MM5 for the region located over the North American Arctic regions. The well predicted near-surface temperature and mixing ratio by the Polar MM5 confirmed the modified physical parameterization schemes that were used in this model are appropriate for the Arctic river regions. Then the extended evaluations of the Polar MM5 simulations over both the North American and Eurasian domains during 15 December 2002 to 15 May 2003 were then carried out. The time series plots and statistical analyses from the observations and the Polar MM5 simulations at 16 stations for the near-surface and vertical profiles at 850 hPa and 500 hPa variables were analyzed. The model was found to reproduce the observed atmospheric state both at magnitude and variability with a high degree of accuracy, especially for temperature and near-surface winds, although there was a slight cold bias that existed near the surface.

  15. Assimilation of GMS-5 satellite winds using nudging method with MM5

    Institute of Scientific and Technical Information of China (English)

    GAO Shanhong; WU Zengmao; YANG Bo

    2006-01-01

    With the aid of Meteorological Information Composite and Processing System (MICAPS), satellite wind vectors derived from the Geostationary Meteorological Statellite-5 (GMS-5) and retrieved by National Satellite Meteorology Center of China (NSMC) can be obtained. Based on the nudging method built in the fifth-generation Mesoscale Model (MM5) of Pennsylvania State University and National Center for Atmospheric Research, a data preprocessor is developed to convert these satellite wind vectors to those with specified format required in MM5. To examine the data preprocessor and evaluate the impact of satellite winds from GMS-5 on MM5 simulations, a series of numerical experimental forecasts consisting of four typhoon cases in 2002 are designed and implemented. The results show that the preprocessor can process satellite winds smoothly and MM5 model runs successfully with a little extra computational load during ingesting these winds, and that assimilation of satellite winds by MM5 nudging method can obviously improve typhoon track forecast but contributes a little to typhoon intensity forecast. The impact of the satellite winds depends heavily upon whether the typhoon bogussing scheme in MM5 was turned on or not. The data preprocessor developed in this paper not only can treat GMS-5 satellite winds but also has capability with little modification to process derived winds from other geostationary satellites.

  16. Analysis on MM5 predictions at Sriharikota during northeast monsoon 2008

    Indian Academy of Sciences (India)

    D Gayatri Vani; S Rambabu; M Rajasekhar; G V Rama; B V Apparao; A K Ghosh

    2011-08-01

    The Indian northeast monsoon is inherently chaotic in nature as the rainfall realised in the peninsular India depends substantially on the formation and movement of low-pressure systems in central and southwest Bay of Bengal and on the convective activity which is mainly due to the moist north-easterlies from Bay of Bengal. The objective of this study is to analyse the performance of the PSU-NCAR Mesoscale Model Version 5 (MM5), for northeast monsoon 2008 that includes tropical cyclones – Rashmi, Khai-Muk and Nisha and convective events over Sriharikota region, the rocket launch centre. The impact of objective analysis system using radiosonde observations, surface observations and Kalpana-1 satellite derived Atmospheric Motion Wind Vectors (AMV) is also studied. The performance of the model is analysed by comparing the predicted parameters like mean sea level pressure (MSLP), intensity, track and rainfall with the observations. The results show that the model simulations could capture MSLP and intensity of all the cyclones reasonably well. The dependence of the movement of the system on the environmental flow is clearly observed in all the three cases. The vector displacement error and percentage of improvement is calculated to study the impact of objective data analysis on the movement and intensity of the cyclone.

  17. Recent trends in Antarctic snow accumulation from Polar MM5 simulations.

    Science.gov (United States)

    Monaghan, Andrew J; Bromwich, David H; Wang, Sheng-Hung

    2006-07-15

    Polar MM5, a mesoscale atmospheric model optimized for use over polar ice sheets, is employed to simulate Antarctic accumulation in recent decades. Two sets of simulations, each with different initial and boundary conditions, are evaluated for the 17yr period spanning 1985-2001. The initial and boundary conditions for the two sets of runs are provided by the (i) European Centre for Medium-Range Weather Forecasts 40 year Reanalysis, and (ii) National Centres for Environmental Prediction-Department of Energy Atmospheric Model Intercomparison Project Reanalysis II. This approach is used so that uncertainty can be assessed by comparing the two resulting datasets. There is broad agreement between the two datasets for the annual precipitation trends for 1985-2001. These generally agree with ice core and snow stake accumulation records at various locations around the continent, indicating broad areas of both upward and downward trends. Averaged over the continent the annual trends are small and not statistically different from zero, suggesting that recent Antarctic snowfall changes do not mitigate current sea-level rise. However, this result does not suggest that Antarctica is isolated from the recent climate changes occurring elsewhere on Earth. Rather, these are expressed by strong seasonal and regional precipitation changes.

  18. MM5 Simulations of the China Regional Climate During the Mid-Holocene

    Institute of Scientific and Technical Information of China (English)

    LIU Yu; HE Jinhai; LI Weiliang; CHEN Longxun; LI Wei; ZHANG Bo

    2010-01-01

    Using a regional climate model MM5 nested with an atmospheric global climate model CCM3, a series of simulations and sensitivity experiments have been performed to investigate responses of the mid-Holocene climate to different factors over China. Model simulations of the mid-Holocene climate change, especially the precipitation change, are in good agreement with the geologic records. Model results show that relative to the present day (PD) climate, the temperature over China increased in the mid-Holocene, and the increase in summer is more than that in winter. The summer monsoon strengthened over the eastern China north of 30°N, and the winter monsoon weakened over the whole eastern China; the precipitation increased over the west part of China, North China, and Northeast China, and decreased over the south part of China. The sensitive experiments indicate that changes in the global climate (large-scale circulation background), vegetation, earth orbital parameter, and CO2 concentration led to the mid-Holocene climate change relative to the PD climate, and changes in precipitation, temperature and wind fields were mainly affected by change of the large-scale circulation background, especially with its effect on precipitation exceeding 50%. Changes in vegetation resulted in increasing of temperature in both winter and summer over China, especially over eastern China; furthermore, its effect on precipitation in North China accounts for 25% of the total change. Change in the orbital parameter produced the larger seasonal variation of solar radiation in the mid-Holocene than the PD, which resulted in declining of temperature in winter and increasing in summer; and also had an important effect on precipitation with an effect equivalent to vegetation in Northeast China and North China. During the mid-Holocene, CO2 content was only 280×l0-6, which reduced temperature in a very small magnitude. Therefore, factors affecting the mid-Holocene climate change over China from

  19. A Tangential Wind Profile for Simulating Strong Tropical Cyclones with MM5

    Institute of Scientific and Technical Information of China (English)

    GAO Shanhong; YANG Bo; WU Zengmao

    2005-01-01

    A new tangential wind profile for simulating strong tropical cyclones is put forward and planted into the NCARAFWA tropical cyclone bogussing scheme in MM5. The scheme for the new profile can make full use of the information from routine typhoon reports, including not only the maximum wind, but also the additional information of the wind speeds of 25.7 and 15.4 ms -1 and their corresponding radii, which are usually provided for strong cyclones. Thus, the new profile can be used to describe the outer structure of cyclones more accurately than by using the earlier scheme of MM5 in which only the maximum wind speed is considered. Numerical experimental forecasts of two strong tropical cyclones are performed to examine the new profile. Results show that by using the new profile the prediction of both cyclones' intensity can be obviously improved, but the effects on the track prediction of the two cyclones are different. It seems that the new profile might be more suitable for strong cyclones with shifted tracks. However, the conclusion is drawn from only two typhoon cases, so more cases are needed to evaluate the new profile.

  20. Numerical evaluation of offshore wind energy resources in Dalian area by MM5%基于MM5模式的大连近海地区风能资源评估

    Institute of Scientific and Technical Information of China (English)

    孙英伟; 康海贵; 任年鑫; 陈兵

    2012-01-01

    利用MM5中尺度气象模式和美国国家环境预报中心提供的1°×1°再分析初始场资料,对大连近海地区的风场进行了网格距为3km的高空间分辨率数值模拟,模拟时段为2000年全年.通过对比3个气象站风速的数值结果与站点观测结果,验证了该模式的有效性.对MM5模式的输出结果进行了后处理,得到了大连近海地区的年平均风速、年平均功率密度和年可利用时间等评估参数的等值线图,对大连市近海风能资源分布情况进行了分析.结果表明,大连近海地区风能资源较为丰富,具有较大的开发价值.%The wind field in Dalian area is simulated at a high spacial resolution of 3 km by using meso-scale atmospheric model MM5.The 1°×1° reanalytical data which is from National Centers for Environmental Prediction of America is used in this study and the computational period covers the whole year 2000.The model is validated by comparing the numerical results with the field observed data from three meteorological stations.The output data are further processed and the contour maps of yearly average wind speed,yearly power density and yearly effective hours are obtained.The distribution of offshore wind energy resources in Dalian area is analyzed.The test results show that the offshore wind energy resource in Dalian area is rich and has great value for development.

  1. Modelling the re-intensification of tropical storm Erin (2007 over Oklahoma: understanding the key role of downdraft formulation

    Directory of Open Access Journals (Sweden)

    Folmer Krikken

    2012-08-01

    Full Text Available This article reports on the inland re-intensification of tropical storm (TS Erin (2007. In this research, the physical processes that resulted in the re-intensification of TS Erin over Oklahoma, USA, on 19 August 2007 was determined and a sensitivity study on microphysics, planetary boundary layer and convective parameterisation schemes was performed in the mesoscale modelling system, MM5. Also, we diagnosed and explained the remarkable difference between model behaviour of the original Kain–Fritsch 1 (KF1 scheme and its revised counterpart (KF2. The numerical results showed only modest sensitivity to the selected microphysics schemes – the relatively simple ‘Simple Ice’ and the advanced Reisner-Graupel. We found a relatively high sensitivity to the selected boundary layer parameterisation. Enhanced mixing in the medium range forecast (MRF scheme leads to a relatively small convective available potential energy (CAPE, a deeper boundary layer and a lower dew point temperature, thus to a relatively stable environment. Therefore, MRF forecasts less precipitation (up to 150 mm than the local mixing scheme, ETA. Model results appeared most sensitive to the selected convection schemes, that is, Grell, KF1 and KF2. With Grell and KF1, Erin intensifies and produces intense precipitation, but its structure remains close to a mesoscale convective system (MCS or squall line rather than of the observed tropical cyclone. Both schemes also simulate the most intense precipitation too far south (100 km compared to observations. On the contrary, KF2 underestimates precipitation, but the track of the convection, the precipitation and the pressure distribution are relatively close to radar and field observations. A sensitivity study reveals that the downdraft formulation is critical to modelling TS Erin's dynamics. Within tropical cyclogenesis, the mid-level relative humidity (RH is generally very high, resulting in very small downdrafts. KF2 generates

  2. 用WRF与MM5模拟1998年三次暴雨过程的对比分析%SIMULATION AND ANALYSIS OF THREE HEAVY RAINFALL PROCESSES IN 1998 WITH WRF AND MM5

    Institute of Scientific and Technical Information of China (English)

    孙健; 赵平

    2003-01-01

    使用NCAR和NOAA的新一代中尺度模式WRF(Weather Research and Forecast)和UCAR/PSU的MM5(v3)模式,对1998年发生在中国的三次强降水过程,即5月的1次华南暴雨过程,7月初的1次淮河流域暴雨过程和7月下旬的1次长江流域暴雨过程进行了数值模拟.模拟结果表明,WRF模式能够成功模拟这几次不同性质的降水过程;与MM5对比,WRF更好地模拟了引起这几次降水过程中的主要天气系统的位置和移动过程,从而使WRF模拟的降水落区好于MM5.但在这几次过程中WRF模拟的降水都较MM5为小,也小于实况值,分析可见,WRF模拟的垂直速度明显小于MM5的模拟结果,这可能是导致模拟的降水偏小的原因之一.

  3. Daily Changes of Spatial Patterns of Meteorological Elements over Pearl River Delta Based on GIS and MM5

    Institute of Scientific and Technical Information of China (English)

    JIANG Xueding; XIA Beicheng; LIN Guangfa; LIN Wenshi

    2009-01-01

    The spatial distribution of meteorological elements is important for understanding the regional meteorology and climate changes. However, previous studies rarely focused on the daily changes of the spatial patterns of meteorological elements due to the limitation of remote sensing (RS) techniques and traditional meteorological methods. In this paper, the regional meteorological elements were simulated by the fifth-generation non-hydrostatic Mesoscale Model (MM5), and the spatial patterns of meteorological elements and their diurnal variations were analyzed in landscape level over the Pearl (Zhujiang) River Delta (PRD), China. The results showed that there were several centers of urban heat islands, cold islands, dry islands, wet islands, high wind over the PRD at noon. The diurnal changes of Moran I of meteorological elements were obvious and they reached the extremum at noon and 2-3 hours after the sunrise. The landscape indices of meteorological elements, such as area-weighted mean Fractal Dimension Index (FRAC_AM), Landscape Shape Index (LSI), Shannon's Diversity Index (SHDI) and Contagion Index (CONTAG), were more variable at about the sunrise, noon and sunset. The occurrence of wave crests and vales of landscape indices was affected by the surface net radiation, turbulence and local circumfluence. The spatial patterns of meteorological elements correlated well with the land surface, thermal exchanges and local circumfluence. A new approach combining GIS, RS and numerical simulatious technologies and the landscape ecology method was presented to analyze spatial patterns of meteorological elements, which may be useful for studying global and regional climate changes.

  4. Use of high-resolution MM5/CALMET/CALPUFF system: SO 2 apportionment to air quality in Hong Kong

    Science.gov (United States)

    Yim, Steve H. L.; Fung, Jimmy C. H.; Lau, Alexis K. H.

    2010-12-01

    Recent research has highlighted the substantial health-related costs of air pollution in the Hong Kong Special Administrative Region (HKSAR) and the potential threat from air pollution to HKSARs economic competitiveness. In order to address the air pollution problems, this paper seeks to analyse the individual contributions of major sulphur dioxide (SO 2) sources in the Pearl River Delta Region (PRDR) (Pearl River Delta + HKSAR) on the air quality in the HKSAR. This study employed the coupling of the MM5/CALMET system with the CALPUFF, the multi-layer, non-steady-state puff dispersion model, where major power plants, marine vessels and vehicles, all in the PRDR, are taken into account. The observation data and simulation results at 11 Hong Kong Environmental Protection Department (HKEPD) general (non-road-side) stations are analyzed. Urban (in-zone) and Rural (out-zone) stations are defined in order to examine the SO 2 contribution of different emission sources in different regions of the HKSAR. The model results show that the contribution of the HKSAR marine sources is significant both in summer and in winter, especially for the locations around the in-zone stations (in general 60%, and 55% in summer and winter respectively). In addition, the contribution of the HKSAR power plants is slightly higher than that of the PRD power plants in early summer, with a contribution difference of up to 20% when the prevailing wind is from the south. However, in late summer, this situation reverses. In winter, the contribution of the PRD power plants is two to three times greater than that of the HKSAR power plants. Moreover, Yantian port affects the northern part of the HKSAR when a northeasterly wind dominates the HKSAR. In order to solve these air pollution problems, the main implication of these results suggests that the HKSAR government, in close co-operation with the Guangdong government, needs to take immediate action.

  5. Intercomparison of Precipitation Simulated by Regional Climate Models over East Asia in 1997 and 1998

    Institute of Scientific and Technical Information of China (English)

    Dong-Kyou LEE; William J. GUTOWSKI, Jr.; Hyun-Suk KANG; Chun-Ji KIM

    2007-01-01

    Regional climate simulations in Asia from May 1997 to August 1998 were performed using the Seoul National University regional climate model (SNURCM) and Iowa State University regional climate model (ALT.MM5/LSM), which were developed by coupling the NCAR/Land Surface Model (LSM) and the Mesoscale Model (MM5). However, for physical processes of precipitation, the SNURCM used the Grell scheme for the convective parameterization scheme (CPS) and the simple ice scheme for the explicit moisture scheme (EMS), while the ALT.MM5/LSM used the Betts-Miller scheme for CPS and the mixed phase scheme for EMS.The simulated precipitation patterns and amounts over East Asia for the extreme climatic summer in 1997 (relative drought conditions) and 1998 (relative flood conditions) were especially focused upon. The ALT.MM5/LSM simulated more precipitation than was observed in 1997 due to more moisture and cloud water in the lower levels, despite weak upward motion. In the SNURCM, strong upward motion resulted in more precipitation than that was observed in 1998, with more moisture and cloud water in the middle levels. In the ALT.MM5/LSM, weak upward motion, unchanged moisture in the lower troposphere, and the decrease in latent heat flux at the surface increased convective precipitation only by 3% for the 1998 summer event. In the SNURCM, strong upward motion, the increase in moisture in the lower troposphere, and the increase in latent heat flux at the surface increased convective precipitation by 48% for the summer of 1998. The main differences between both simulations were moisture availability and horizontal momentum transport in the lower troposphere, which were also strongly influenced by large-scale forcing.

  6. ESTIMATION OF THE OPTICAL TURBULENCE (C2 N AND SEEING FROM MM5 DATA IN PARANAL/ARMAZONES SITE

    Directory of Open Access Journals (Sweden)

    O. Cuevas

    2011-01-01

    Full Text Available El modelo meteorológico MM5 se ha testeado como una buena herramienta de pronóstico de variables meteorológicas en el norte de Chile. Configurando el MM5 en alta resolución horizontal, vertical y temporal se probaron dos modelos para estimar el perfil vertical de la turbulenciaóptica (C2n y seeing en Paranal y Armazones. El modelo AFGL (M1 y el modelo de Masciadri (M2 calculan la estructura vertical de C2n usando en sus ecuaciones parámetros meteorológicos como la magnitud del viento, temperatura, presión, humedad, temperatura potencial y TKE. Se probaron diferentes parametrizaciones de los procesos físicos atmosféricos en el modelo MM5, donde la parametrización de capa límite Gayno-Seaman y el método M2 tienen el mejor resultado. Estos resultados fueron comparados con los datos registrados en las campañas de medición en Paranal entre noviembre y diciembre de 2007, donde se usaron simultáneamente los instrumentos SCIDAR y DIMM midiendo C2n y seeing. Los resultados muestran que el C2n simulado tiene muy buena correspondencia en casi todo el perfil comparado con las mediciones de SCIDAR, pero cerca de la superficie la diferencia es alta, porque los instrumentos toman en cuenta la turbulencia provocada por los edificios de los telescopios, y cerca del suelo el modelo MM5 tiene errores sistemáticos. En Paranal el RMSE de seeing en promedio sobre 12 días es 0.45 arcsec y en Armazones el RMSE de seeing promedio es 0.19 arcsec.

  7. Thermally driven circulation in a region of complex topography: comparison of wind-profiling radar measurements and MM5 numerical predictions

    Directory of Open Access Journals (Sweden)

    L. Bianco

    2006-07-01

    Full Text Available The diurnal variation of regional wind patterns in the complex terrain of Central Italy was investigated for summer fair-weather conditions and winter time periods using a radar wind profiler. The profiler is located on a site where interaction between the complex topography and land-surface produces a variety of thermally and dynamically driven wind systems. The observational data set, collected for a period of one year, was used first to describe the diurnal evolution of thermal driven winds, second to validate the Mesoscale Model 5 (MM5 that is a three-dimensional numerical model. This type of analysis was focused on the near-surface wind observation, since thermally driven winds occur in the lower atmosphere. According to the valley wind theory expectations, the site – located on the left sidewall of the valley (looking up valley – experiences a clockwise turning with time. Same characteristics in the behavior were established in both the experimental and numerical results.

    Because the thermally driven flows can have some depth and may be influenced mainly by model errors, as a third step the analysis focuses on a subset of cases to explore four different MM5 Planetary Boundary Layer (PBL parameterizations. The reason is to test how the results are sensitive to the selected PBL parameterization, and to identify the better parameterization if it is possible. For this purpose we analysed the MM5 output for the whole PBL levels. The chosen PBL parameterizations are: 1 Gayno-Seaman; 2 Medium-Range Forecast; 3 Mellor-Yamada scheme as used in the ETA model; and 4 Blackadar.

  8. Consistency and inconsistency in testing biomarkers in breast cancer. A GRELL study in cut-off variability in the Romance language countries.

    Science.gov (United States)

    Crocetti, Emanuele; Caldarella, Adele; Ferretti, Stefano; Ardanaz, Eva; Arveux, Patrick; Bara, Simona; Barrios, Enrique; Bento, Maria J; Bordoni, Andrea; Buzzoni, Carlotta; Candela, Giuseppina; Colombani, Françoise; Delafosse, Patricia; Federico, Massimo; Francart, Julie; Giacomin, Adriano; Grosclaude, Pascale; Guizard, Anne V; Izarzugaza, Isabel; Konzelmann, Isabelle; La Rosa, Francesco; Lapotre, Benedicte; Leone, Nathalie; Ligier, Karine; Mangone, Lucia; Marcos-Gragera, R; Martinez, Ruth; Michelena, Maria J; Michiara, Maria; Miranda, Ana; Molinié, Florence; Mugarza-Gomez, Conception; Paci, Eugenio; Piffer, Silvano; Puig-Vives, Montserrat; Sacchettini, Claudio; Sánchez, Maria J; Traina, Adele; Tretarre, Brigitte; Tumino, Rosario; Van Vaerenbergh, Elke; Velten, Michel; Woronoff, Anne S

    2013-08-01

    Biological markers are crucial factors in order to differentiate female breast cancers and to determine the right therapy. This study aims at evaluating whether testing for biomarkers for female breast cancer has similar frequency and characteristics across and within countries. Population-based cancer registries of the Association for cancer registration and epidemiology in Romance language countries (GRELL) were asked to complete a questionnaire on biomarkers testing. The data collected referred to invasive female breast cancer cases diagnosed between 2004 and 2009. The investigation focused on 1) the overexpression and amplification of the human epidermal growth factor receptor 2 oncogene (HER2); 2) the expression of oestrogen (ER) and progesterone (PgR) receptors; and 3) the proliferation index (PI). Weighted percentages, the heterogeneity among and within countries, and the correlation between responses and calendar years were evaluated. The study was based on 19,644 breast cancers. Overall, 85.9% of the cases were tested for HER2, 91.8% for both ER and PgR, and 74.1% for proliferative markers. For HER2 and ER-PgR, the frequency of testing increased from 2004 to 2009. Testing varied among countries (HER2 from 82.0% to 95.9%, ER-PgR from 89.3% to 98.9%, PI from 10% to 92%) and also within the same country (e.g. HER2 in Italy from 51% to 99%) as well as within single cancer registries. The most relevant differences were in the scores for positive/negative/not clearly defined HER2 (e.g. HER2 was defined positive if IHC 3+ in 21/33 registries), and in the cut-off of positive cells for ER/PgR (from >0% to >30%) and PI positivity (from >0% to >20%). Biological markers are widely tested in the Romance language countries; however, the parameters defining their positivity may vary, raising concerns about homogeneity in breast cancer classification and treatment. Copyright © 2013 Elsevier Ltd. All rights reserved.

  9. MM5V3对东亚区域大气环流模拟能力的检测%Testing the Ability of MM5V3 to Simulate Atmosphere Circulation in East Asia

    Institute of Scientific and Technical Information of China (English)

    赵得明; 符淙斌; 苏炳凯

    2008-01-01

    为了检验参加亚洲区域气候模式国际比较计划(RMIP)的数值模式MM5V3模拟气候及其变化的能力,对利用该模式完成的东亚区域(包括大部分亚洲大陆、西太平洋、孟加拉湾和南海地区)1989~1998年10年模拟试验积分结果,用奇异值分解(SVD)分析了模式模拟和观测(NCEP/NCAR再分析资料)的500 hPa月平均高度场之间的关系,得到检验数值模式模拟气候及其变化能力的两种有效指标:模态相关系数和异性相关系数.对500 hPa月平均高度场及其距平场和冬、夏季的月平均高度距平场进行SVD分析,由North检验显著的前两对模态都有很高的模态相关系数和异性相关系数分布.结果表明: MM5V3对500 hPa月平均高度场气候态及其异常变化有一定的模拟能力,模拟的冬季比模拟的夏季情况要更好.

  10. 2001年"V5D、MM5V3培训班”成功举办

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    中国气象科学研究院信息中心在2000年举办三期"V5D培训班”的基础上,在新世纪伊始又连续举办了四期.今年我们面向全国的气象业务系统招生受到了各地的欢迎和积极响应,纷纷报名参加培训,使原计划只举办两期的培训班扩充到四期,学员由原计划的每班12人增加到每班20人. Vis5D是一个可对大型5-D网格数据集在三维空间进行交互式可视化的软件系统.用Vis5D系统可以制作出各种五维网格图形,如等值面图、等高线剖面图、彩色剖面图、立体透视图等,并可对图形进行旋转和实时动画,还具有独特的对风轨迹进行跟踪的特性.Vis5D系统可广泛应用于气象、海洋、环保等领域中数值模式产品的可视化,大大改善产品的可视效果.MM5V3是美国大学大气研究协会(UCAR)和宾夕法尼亚州立大学(PSU)开发研制的第五代中尺度模式系列中的最新版本.通过短期培训科技人员可尽快在微机上建立起模式运行环境,开展工作. 参加培训的学员来自气象、民航、海洋、水利、部队等系统的40多个单位的60多名学员,其中大多数学员来自全国各省市自治区的气象科研所、人影办、省气象台以及在读研究生等.举办培训班的目的是为全国气象科研工作者提高其业务能力和水平,打造一个硬件环境,缩短掌握最新技术的进程.有关Vis5D、MM5V3详细内容请参阅由贝刚同志在期刊上发表的两篇文章;2000年11期"用Vis5D软件包在PC机上实现模式预报输出结果的可视化”与2001年第2期"在微机上运行MM5V3模式系统”. 本培训班计划在今年秋季继续举办,欢迎有意参加者与我们联系.联系电话:010-62187798 联系人:贝刚、李莉. (中国气象科学研究院 李莉)

  11. GPS-Derived Precipitable Water Compared with the Air Force Weather Agency’s MM5 Model Output

    Science.gov (United States)

    2002-03-26

    SC 32.90 -80.03 15 Charleston, SC (CHA1) 23.63 CRP Corpus Christi , TX 27.77 -97.50 14 Aransas Pass, TX (ARP3) 44.01 DEN Denver, CO 39.77 -104.88 1611...values with GPS-derived PW values at five GPS sites in the Madrid Sierra region of central Spain. The case was during 2-15 December 1996 and

  12. MM5 Simulations of the China Regional Climate During the LGM.Ⅰ: Influence of CO2 and Earth Orbit Change

    Institute of Scientific and Technical Information of China (English)

    LIU yu; HE Jinhai; LI Weiliang; CHEN Longxun

    2008-01-01

    Using a regional climate model MM5 nested to an atmospheric global climate model CCM3, a series of simulations and sensitivity experiments have been performed to investigate the relative Last Glacial Maximum (LGM) climate response to different mechanisms over China. Model simulations of the present day (PD) climate and the LGM climate change are in good agreement with the observation data and geological records, especially in the simulation of precipitation change. Under the PD and LGM climate, changes of earth orbital parameters have a small influence on the annual mean temperature over China.However, the magnitude of the effect shows a seasonal pattern, with a significant response in winter. Thus,this influence cannot be neglected. During the LGM, CO2 concentration reached its lowest point to 200 ppmv. This results in a temperature decrease over China. The influences of CO2 concentration on climate show seasonal and regional patterns as well, with a significant influence in winter. On the contrary, CO2concentration has less impact in summer season. In some cases, temperature even increases with decreasing in CO2 concentration. This temperature increase is the outcome of decrease in cloud amount; hence increase the solar radiation that reached the earth's surface. This result suggests that cloud amount plays a very important role in climate change and could direct the response patterns of some climate variables such as temperature during certain periods and over certain regions. In the Tibetan Plateau, the temperature responses to changes of the above two factors are generally weaker than those in other regions because the cloud amount in this area is generally more than in the other areas. Relative to the current climate, changes in orbital parameters have less impact on the LGM climate than changes in CO2 concentration. However,both factors have rather less contributions to the climate change in the LGM. About 3%-10% changes in the annual mean temperature are

  13. Use of high-resolution MM5/CALMET/CALPUFF system SO{sub 2} apportionment to air quality in Hong Kong

    Energy Technology Data Exchange (ETDEWEB)

    Yim, S.H.L.; Fung, J.C.H.; Lau, A.K.H. [Hong Kong University of Science & Technology, Kowloon (China). Inst. of Environment

    2010-12-15

    Recent research has highlighted the substantial health-related costs of air pollution in the Hong Kong Special Administrative Region (HKSAR) and the potential threat from air pollution to HKSARs economic competitiveness. In order to address the air pollution problems this paper seeks to analyse the individual contributions of major sulphur dioxide (SO{sub 2}) sources in the Pearl River Delta Region (PRDR) (Pearl River Delta + HKSAR) on the air quality in the HKSAR. This study employed the coupling of the MM5/CALMET system with the CALPUFF, the multi-layer non-steady-state puff dispersion model where major power plants, marine vessels and vehicles all in the PRDR are taken into account. The observation data and simulation results at 11 Hong Kong Environmental Protection Department (HKEPD) general (non-road-side) stations are analyzed. Urban (in-zone) and Rural (out-zone) stations are defined in order to examine the SO{sub 2} contribution of different emission sources in different regions of the HKSAR. The model results show that the contribution of the HKSAR marine sources is significant both in summer and in winter especially for the locations around the in-zone stations (in general 60% and 55% in summer and winter respectively). In addition the contribution of the HKSAR power plants is slightly higher than that of the PRD power plants in early summer with a contribution difference of up to 20% when the prevailing wind is from the south. However in late summer this situation reverses. In winter the contribution of the PRD power plants is two to three times greater than that of the HKSAR power plants. Moreover Yantian port affects the northern part of the HKSAR when a northeasterly wind dominates the HKSAR. In order to solve these air pollution problems the main implication of these results suggests that the HKSAR government in close co-operation with the Guangdong government needs to take immediate action.

  14. 用WRF与MM5模拟1998年三次暴雨过程的对比分析

    Institute of Scientific and Technical Information of China (English)

    孙健; 赵平

    2003-01-01

    使用NCAR和NOAA的新一代中尺度模式WRF(Weather Research and Forecast)和UCAR/PSU的MM5(v3)模式,对1998年发生在中国的三次强降水过程,即5月的1次华南暴雨过程,7月初的1次淮河流域暴雨过程和7月下旬的1次长江流域暴雨过程进行了数值模拟。模拟结果表明,WRF模式能够成功模拟这几次不同性质的降水过程;与MM5对比,WRF更好地模拟了引起这几次降水过程中的主要天气系统的位置和移动过程,从而使WRF模拟的降水落区好于MM5。但在这几次过程中WRF模拟的降水都较MM5为小,也小于实况值,分析可见,WRF模拟的垂直速度明显小于MM5的模拟结果,这可能是导致模拟的降水偏小的原因之一。

  15. MM5 Simulations of the China Regional Climate During the LGM.Ⅱ: Influence of Change of Land Area, Vegetation, and Large-scale Circulation Background

    Institute of Scientific and Technical Information of China (English)

    LIU Yu; HE Jinhai; LI Weiliang; CHEN Longxun

    2008-01-01

    Using a regional climate model MM5 nested to an atmospheric global climate model CCM3, a series of simulations and sensitivity experiments have been performed to investigate the relative LGM climate response to changes of land-sea distribution, vegetation, and large-scale circulation background over China.Model results show that compared with the present climate, the fluctuations of sea-land distribution in eastern Asia during the LGM result in the temperature decrease in winter and increase in summer. It has significant impact on the temperature and precipitation in the east coastal region of China. The impact on precipitation in the east coastal region of China is the most significant one, with 25%-50% decrease in the total precipitation change during the LGM. On the other hand, the changes in sea-land distribution have less influence on the climate of inland and western part of China. During the LGM, significant changes in vegetation result in temperature alternating with winter increase and summer decrease, but differences in the annual mean temperature are minor. During the LGM, the global climate, i.e., the large-scale circulation background has changed significantly. These changes have significant influences on temperature and precipitation over China. They result in considerable temperature decreases in this area, and direct the primary patterns and characteristics of temperature changes. Results display that, northeastern China has the greatest temperature decrease, and the temperature decrease in the Tibetan Plateau is larger than in the eastern part of China located at the same latitude. Moreover, the change of large-scale circulation background also controls the pattern of precipitation change. Results also show that, most of the changes in precipitation over western and northeastern parts of China are the consequences of changing large-scale circulation background, of which 50%-75% of precipitation changes over northern and eastern China are the

  16. Comparación de las salidas del modelo MM5v3 con datos observados en la Isla del Coco, Costa Rica

    Directory of Open Access Journals (Sweden)

    Tito José Maldonado Mora

    2010-12-01

    Full Text Available Se presenta la comparación de las salidasdel modelo MM5 con datos tomados insitu en la Isla del Coco, Costa Rica. Lasobservaciones fueron realizadas en tresexpediciones hechas a la isla en octubre del2007, abril del 2008 y marzo del 2009. Paraejecutar las simulaciones se utilizaron lassalidas del modelo de tiempo atmósfericodel National Center for EnvironmentalPrediction (NCEP, que inició a las 00UTC y se empleó la retroalimentacióndinámica en ambas direcciones.Se configuraron cuatro dominios de 90,30, 10 y 3,3 km (42 x 47, 76 x 85, 100x 121, 73 x 73 puntos con 35 niveles enla vertical y con pronósticos de hasta 48horas, cada tres horas. Se encontró quecon las configuraciones físicas elegidasse realiza una mejor representación delos periodos húmedos que de los periodoscon mayor precipitación en dicha zona.Tales resultados se manifiestan en laspredicciones de humedad relativa yprecipitación, lo que confirma la relaciónentre estas dos variables en la zona.Sin embargo, no se encontró una adecuadasimulación de los patrones de radiaciónde onda corta incidente.La temperaturaha mostrado valores acordes con otrosexperimentos, mientras que el vientopresentó una mejor simulación en losniveles medios que en capa límite.

  17. Application of the MM5/CALMET/CALPUFF system to Guanzhong basin area for SO2 emission control%MM5/CALMET/CALPUFF数值模式在关中地区SO2环境空气总量控制中的应用

    Institute of Scientific and Technical Information of China (English)

    蒋宁洁; 王繁强; 苑魁魁

    2012-01-01

    This paper seeks to analyze the corresponding contributions of major sulphuric dioxide (S02) emissions to the total air-quality influence in hoping to reduce the pollution in Guanzhong Basin Area (GZBA) . In proceeding with our study, we have attempted to adopt the coupling of the MM5/CALMET system with the CALPUFF model, the multi-layer, non-steady-state puff dispersion model, which takes the major power plants and plane sources and all the rest in the GZR 2007, into account. We have also analyzed the observation data and simulation results gained from the 18 stations of Guanzhong Environmental Protection Departments. In addition, we have also defined the Urban (in-zone) and Rural (out-zone) stations in order to examine the SO2 contribution of different emission sources in different regions of the area. The survey and statistics results show that the annual concentration assessment and monitoring values, the time changing trend of the predicted and monitoring Daily average density are basically in mutual conformity. The same is basically true with the axis of the pollutant dispersion and the main wind direction, with Xi an, Xi-anyang and Tongchuan mainly taking the northeast and southwest direction, while Baoji and Shangluo mainly following the northwest and southeast direction, however, Weinan and Qinling mountainous areas tend to take the east and west directions. Our survey also shows that the air pollution influences the contaminants of the special terrain and meteorological conditions. Specifically speaking, we have taken the maximum points of the S02 annual concentration as the principal control points, while the secondary standard of annual concentration is used to judge the pollution situation by using the equal proportion-reducing method. If ignoring die difference of the boundaries between the urban and rural areas, the total SO2 emissions of the entire area put together have been worked out at about 600 000 tons/year in the GZR, with about 90 000 tons

  18. The Effects of Model Resolution on the Simulation of Regional Climate Extreme Events

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    The fifth-generation Pennsylvania State University/NCAR Mesoscale Model Version 3 (MM5V3) was used to simulate extreme heavy rainfall events over the Yangtze River Basin in June 1999. The effects of model's horizontal and vertical resolution on the extreme climate events were investigated in detail. In principle, the model was able to characterize the spatial distribution of monthly heavy precipitation. The results indicated that the increase in horizontal resolution could reduce the bias of the modeled heavy rain and reasonably simulate the change of daily precipitation during the study period. A finer vertical resolution led to obviously improve rainfall simulations with smaller biases, and hence, better resolve heavy rainfall events. The increase in both horizontal and vertical resolution could produce better predictions of heavy rainfall events. Not only the rainfall simulation altered in the cases of different horizontal and vertical grid spacing, but also other meteorological fields demonstrated diverse variations in terms of resolution change in the model. An evident improvement in the simulated sea level pressure resulted from the increase of horizontal resolution, but the simulation was insensitive to vertical grid spacing. The increase in vertical resolution could enhance the simulation of surface temperature as well as atmospheric circulation at low levels, while the simulation of circulation at middle and upper levels were found to be much less dependent on changing resolution. In addition, cumulus parameterization schemes showed high sensitivity to horizontal resolution. Different convective schemes exhibited large discrepancies in rainfall simulations with regards to changing resolution. The percentage of convective precipitation in the Grell scheme increased with increasing horizontal resolution. In contrast, the Kain-Fritsch scheme caused a reduced ratio of convective precipitation to total rainfall accumulations corresponding to increasing

  19. Customization of regional climate model (RegCM4) over Indian region

    Science.gov (United States)

    Nayak, S.; Mandal, M.; Maity, S.

    2017-01-01

    The regional climate model (RegCM4) is customized for 10-year climate simulation over Indian region through sensitivity studies on cumulus convection and land surface parameterization schemes. The model is configured over 30° E-120° E and 15° S-45° N at 30-km horizontal resolution with 23 vertical levels. Six 10-year (1991-2000) simulations are conducted with the combinations of two land surface schemes (BATS, CLM3.5) and three cumulus convection schemes (Kuo, Grell, MIT). The simulated annual and seasonal climatology of surface temperature and precipitation are compared with CRU observations. The interannual variability of these two parameters is also analyzed. The results indicate that the model simulated climatology is sensitive to the convection as well as land surface parameterization. The analysis of surface temperature (precipitation) climatology indicates that the model with CLM produces warmer (dryer) climatology, particularly over India. The warmer (dryer) climatology is due to the higher sensible heat flux (lower evapotranspiration) in CLM. The model with MIT convection scheme simulated wetter and warmer climatology (higher precipitation and temperature) with smaller Bowen ratio over southern India compared to that with the Grell and Kuo schemes. This indicates that a land surface scheme produces warmer but drier climatology with sensible heating contributing to warming where as a convection scheme warmer but wetter climatology with latent heat contributing to warming. The climatology of surface temperature over India is better simulated by the model with BATS land surface model in combination with MIT convection scheme while the precipitation climatology is better simulated with BATS land surface model in combination with Grell convection scheme. Overall, the modeling system with the combination of Grell convection and BATS land surface scheme provides better climate simulation over the Indian region.

  20. A mesoscale model used in the Polar regions: modification and verification

    Institute of Scientific and Technical Information of China (English)

    Ma Yan; Chen Shang

    2006-01-01

    A polar version of mesoscale model, Polar MM5 is introduced in the paper. The modifications for the polar MM5 dynamics and physics compared with standard MM5 are described. Additionally, parallel simulations of the Polar MM5 and original MM5 reveal that the Polar MM5 reproduces better near-surface variables forecasts than the original MM5 over the North American Arctic regions. The well predicted near surface temperature and mixing ratio by the Polar MM5 confirm the modified physical parameterization schemes in the Polar MM5 are appropriate for the research region.

  1. Investigation of Atmospheric Modelling Framework for Better Reconstruction on Historical Extreme Precipitation Event in PMP Estimation

    Science.gov (United States)

    Chen, X.; Hossain, F.; Leung, L. R.

    2015-12-01

    During May 1-2, 2010, a record-breaking storm hit Nashville, and caused huge humanity and societal loss. It raises the importance of forecasting/reconstructing these types of extreme weather systems once again, in the meanwhile providing an excellent case for such atmospheric modelling studies. However, earlier studies suggest that successful reconstruction of this event depends on and is sensitive to a number of model options, making it difficult to establish a better model framework with more confidence. In this study we employed the Weather Research and Forecast (WRF) model to investigate how this extreme precipitation event is sensitive to the model configuration, and identified options that would produce better results. We tested several combinations of modelling grid sizes together with initial/boundary conditions (IC/BC). At different grid sizes, we conducted a set of tests on various combinations of microphysics (Morrison, new Thompson and WSM5) and cumulus process (Kain-Fristch, Grell-Devenyi and Grell-Freitas) parameterization schemes. The model results were intensively evaluated under bias analysis as well as other metrics (probability of detection, bias, false alerts, HSS, ETS). The evaluation suggests that in general, simulation results benefit from finer model grids (5km). At 5km level, NCEP2 or NAM IC/BCs are more representative for the 2010 Nashville storm. There are no universally good parameterization schemes, but the WSM5 microphysics scheme, Kain-Fristch and Grell-Freitas cumulus schemes are recommended over other tested schemes. These better schemes would help to make better estimation of PMP in the region.

  2. Changes in Intense Rainfall Events over the Central United States in AOGCM-Driven Regional Climate Model Simulations

    Science.gov (United States)

    Daniel, A. R.; Arritt, R. W.; Groisman, P. Y.

    2014-12-01

    We have evaluated trends in extreme precipitation frequency for the central United States (Groisman et al. 2012) using atmosphere-ocean global climate model (AOGCM) driven regional climate simulations. Nested regional climate model simulations were conducted using RegCM4.4 over the CORDEX-North America domain with 50 km grid spacing. Initial and lateral boundary conditions are taken from the HadGEM2-ES and GFDL-ESM2M AOGCMs (for RCP8.5 emissions scenario) to simulate present and future climate (1951-2098). For each run, RegCM4 uses three different convection schemes: Emanuel scheme, Grell scheme, and Mixed scheme which uses the Emanuel scheme over water and Grell over land.Current findings show the regional climate simulations are of the same magnitude of average frequency for heavy ( 25.4-76.2 mm/day), and extreme (154.9+ mm/day) precipitation events while very heavy events (76.2+ mm/day) were less frequent by an order of magnitude. For current and recent past climate (1951-2005), frequency of precipitation events is similar in both HadGEM2-ES and GFDL-ESM2M AOGCM-driven regional climate simulations with most variation due to the convection scheme being used. Initial results seem to exhibit similar trends in the increase of frequency for each precipitation event as is seen in observations. In accordance with Groisman et al. (2012), preliminary findings also show months during the cold season had more frequent heavy events in comparison to very heavy and extreme events while months during the warm season had more frequent very heavy and extreme events in comparison to heavy events. Further analysis will better determine the correlation and accuracy of these regional climate simulations.

  3. INTERCOMPARISON OF ALTERNATIVE VEGETATION DATABASES FOR REGIONAL AIR QUALITY MODELING

    Science.gov (United States)

    Vegetation cover data are used to characterize several regional air quality modeling processes, including the calculation of heat, moisture, and momentum fluxes with the Mesoscale Meteorological Model (MM5) and the estimate of biogenic volatile organic compound and nitric oxide...

  4. Estudo da energética modal para episódios de ZCAS. Parte II: impacto da resolução do modelo e da parametrização de convecção Study of the modal energetics for SACZ episodes. Part II: Impact of the model resolution and the convection parameterization

    Directory of Open Access Journals (Sweden)

    Renata Weissmann Borges Mendonça

    2008-12-01

    Full Text Available O desempenho do Modelo Global do Centro de Previsão de Tempo e Estudos Climáticos (CPTEC em simular a energética modal para um composto de sete episódios de Zona de Convergência do Atlântico Sul (ZCAS é avaliado, enfatizando-se a influência da resolução espacial do modelo e de três diferentes parametrizações de convecção profunda: Kuo, Relaxed Arakawa-Schubert (RAS e Grell na partição vertical de energia entre os modos externos e internos, e as trocas de energia entre os modos horizontais de oscilação Rossby, Kelvin, Misto Rossby-Gravidade, Gravidade Oeste e Leste. Os resultados mostraram que as previsões utilizando os esquemas de convecção profunda Kuo, RAS e Grell foram semelhantes entre si e apresentaram uma boa concordância em relação aos padrões obtidos na parte observacional (Parte I deste artigo. O emprego de diferentes esquemas de convecção profunda não apresentou impactos significativos na partição e interação de energia entre os modos verticais e horizontais. Um impacto maior foi obtido com o aumento da resolução vertical das análises e do modelo, de 28 para 42 níveis, em que um maior número de modos internos apresenta um papel relevante nas trocas horizontais e verticais de energia.The performance of the CPTEC Global Model in simulating the modal energetics for a composite of seven South Atlantic Convergence Zone (SACZ episodes was evaluated, emphasizing the influence of the model resolution and the three different deep convection parameterizations: Kuo, Relaxed Arakawa-Schubert (RAS and Grell on the vertical energy partition between external and internal modes and on the energy interactions within and between various horizontal oscillation modes: Rossby, Kelvin, Mixed Rossby-Gravity and West and East Gravity. The results showed that the model predictions using the Kuo, RAS and Grell deep convection schemes were similar with each other, and had a good agreement with the patterns obtained in the

  5. Improvement of snowpack simulations in a regional climate model

    Energy Technology Data Exchange (ETDEWEB)

    Jin, J.; Miller, N.L.

    2011-01-10

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

  6. THE APPLICATION OF HOMEMADE FY-2 SATELLITE INFRARED DATA TO MM5

    Institute of Scientific and Technical Information of China (English)

    LIU Qing; SHEN Tong-li

    2006-01-01

    @@ 1 INTRODUCTION In the end of 1980's, an operational system for 3-D variation and assimilation of meteorological data was set up in the U.S.A that supplemented data assimilation,retrieval of satellite data and numerical prediction each other. NWP was thus improved. Towards the end of 1990's, satellite observations were extensively used in NWP at ECMWF to upgrade the quality of analysis and forecasting.

  7. On the Ability of the Regional Climate Model RIEMS to Simulate the Present Climate over Asia

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    A continuous 10-year simulation in Asia for the period of 1 July 1988 to 31 December 1998 was conducted using the Regional Integrated Environmental Model System (RIEMS) with NCEP Reanalysis Ⅱ data as the driving fields. The model processes include surface physics state package (BATS le), a Holtslag explicit planetary boundary layer formulation, a Grell cumulus parameterization, and a modified radiation package (CCM3). Model-produced surface temperature and precipitation are compared with observations from 1001 meteorology stations distributed over Asia and with the 0.5°× 0.5° CRU gridded dataset. The analysis results show that: (1) RIEMS reproduces well the spatial pattern and the seasonal cycle of surface temperature and precipitation; (2) When regionally averaged, the seasonal mean temperature biases are within 1-2°C. For precipitation, the model tends to give better simulation in winter than in summer,and seasonal precipitation biases are mostly in the range of -12%-50%; (3) Spatial correlation coefficients between observed and simulated seasonal precipitation are higher in north of the Yangtze River than in the south and higher in winter than in summer; (4) RIEMS can well reproduce the spatial pattern of seasonal mean sea level pressure. In winter, the model-simulated Siberian high is stronger than the observed. In summer, the simulated subtropical high is shifted northwestwards; (5) The temporal evolution of the East Asia summer monsoon rain belt, with steady phases separated by more rapid transitions, is reproduced.

  8. Regional integrated environmental model system and its simulation of East Asia summer monsoon

    Institute of Scientific and Technical Information of China (English)

    XIONG Zhe; FU CongBin; YAN XiaoDong

    2009-01-01

    A continuous 22-year simulation in Asia for the period of 1 January 1979 to 31 December 2000 was conducted using the Regional Integrated Environmental Model System (RIEMS 2.0) with NCEP Reanalysis Ⅱ data as the driving fields.The model processes include surface physics state package (BATS le),a Grell cumulus parameterization,and a modified radiation package (CCM3) with the focus on the ability of the model to simulate the summer monsoon over East Asia.The analysis results show that (1)RIEMS reproduces well the spatial pattern and the seasonal cycle of surface temperature.When regionally averaged,the summer mean temperature biases are within 1-2℃.(2) For precipitation,the model reproduces well the spatial pattern,and temporal evolution of the East Asia summer monsoon rain belt,with steady phases separated by more rapid transitions,is reproduced.The rain belt simulated by RIEMS 2.0 is closer to observation than by RIEMS 1.0.(3) RIEMS 2.0 can reasonably reproduce the large-scale circulation.

  9. A coupled atmosphere and multi-layer land surface model for improving heavy rainfall simulation

    Directory of Open Access Journals (Sweden)

    M. Haggag

    2008-04-01

    Full Text Available A multi-layer land surface model (SOLVEG is dynamically coupled to the non-hydrostatic atmospheric model (MM5 in order to represent better spatial variations and changes in land surface characteristics compared with the land surface parameterization schemes included in the MM5. In this coupling, calculations of the atmosphere and land surface models are carried out as independent tasks of different processors; a model coupler controls these calculations and data exchanges among models using Message Passing Interface (MPI. This coupled model is applied to the record-breaking heavy rain events occurred in Kyushu Island, the southernmost of Japan's main islands, from 20 July to 25 July in 2006. The test computations are conducted by using both the developed coupled model and the original land surface parameterization of MM5. The result of these computations shows that SOLVEG reproduce higher ground temperature than land surface parameterization schemes in the MM5. This result indicates the feedback of land surface processes between MM5 and SOLVEG plays an important role in the computation. The most pronounced difference is in the rainfall simulation that shows the importance of coupling SOLVEG and MM5. The coupled model accurately reproduces the heavy rainfall events observed in Kyushu Island compared to the original MM5 from both the spatial and temporal point of view. This paper clearly shows that realistic simulation of rainfall event strongly depends on land-surface processes interacting with cloud development that depends on surface heat and moisture fluxes, which in turn are mainly determined by land surface vegetation and soil moisture storage. Soil temperature/moisture changes significantly affect the localized precipitation and modest improvement in the land surface representation can enhance the heavy rain simulation. MM5-SOLVEG coupling shows a clear image of land surface-atmosphere interactions and the dynamic feedback on

  10. Numerical Simulations of the 1 May 2012 Deep Convection Event over Cuba: Sensitivity to Cumulus and Microphysical Schemes in a High-Resolution Model

    Directory of Open Access Journals (Sweden)

    Yandy G. Mayor

    2015-01-01

    Full Text Available This paper evaluates the sensitivity to cumulus and microphysics schemes, as represented in numerical simulations of the Weather Research and Forecasting model, in characterizing a deep convection event over the Cuban island on 1 May 2012. To this end, 30 experiments combining five cumulus and six microphysics schemes, in addition to two experiments in which the cumulus parameterization was turned off, are tested in order to choose the combination that represents the event precipitation more accurately. ERA Interim is used as lateral boundary condition data for the downscaling procedure. Results show that convective schemes are more important than microphysics schemes for determining the precipitation areas within a high-resolution domain simulation. Also, while one cumulus scheme captures the overall spatial convective structure of the event more accurately than others, it fails to capture the precipitation intensity. This apparent discrepancy leads to sensitivity related to the verification method used to rank the scheme combinations. This sensitivity is also observed in a comparison between parameterized and explicit cumulus formation when the Kain-Fritsch scheme was used. A loss of added value is also found when the Grell-Freitas cumulus scheme was activated at 1 km grid spacing.

  11. A Model Study of the Salish Sea Estuarine Circulation

    Science.gov (United States)

    2011-06-01

    Canal (HCN) to Main Basin (MB; Gregg and Pratt 2010) and South Sound to Main Basin (through Ta- coma Narrows; Seim and Gregg 1997), whereas Whidbey Basin...sortium fifth-generation Pennsylvania State University– National Center for Atmospheric Research Mesoscale Model (MM5) regional forecast model (Mass

  12. Impacts of WRF Physics and Measurement Uncertainty on California Wintertime Model Wet Bias

    Energy Technology Data Exchange (ETDEWEB)

    Chin, H S; Caldwell, P M; Bader, D C

    2009-07-22

    The Weather and Research Forecast (WRF) model version 3.0.1 is used to explore California wintertime model wet bias. In this study, two wintertime storms are selected from each of four major types of large-scale conditions; Pineapple Express, El Nino, La Nina, and synoptic cyclones. We test the impacts of several model configurations on precipitation bias through comparison with three sets of gridded surface observations; one from the National Oceanographic and Atmospheric Administration, and two variations from the University of Washington (without and with long-term trend adjustment; UW1 and UW2, respectively). To simplify validation, California is divided into 4 regions (Coast, Central Valley, Mountains, and Southern California). Simulations are driven by North American Regional Reanalysis data to minimize large-scale forcing error. Control simulations are conducted with 12-km grid spacing (low resolution) but additional experiments are performed at 2-km (high) resolution to evaluate the robustness of microphysics and cumulus parameterizations to resolution changes. We find that the choice of validation dataset has a significant impact on the model wet bias, and the forecast skill of model precipitation depends strongly on geographic location and storm type. Simulations with right physics options agree better with UW1 observations. In 12-km resolution simulations, the Lin microphysics and the Kain-Fritsch cumulus scheme have better forecast skill in the coastal region while Goddard, Thompson, and Morrison microphysics, and the Grell-Devenyi cumulus scheme perform better in the rest of California. The effect of planetary boundary layer, soil-layer, and radiation physics on model precipitation is weaker than that of microphysics and cumulus processes for short- to medium-range low-resolution simulations. Comparison of 2-km and 12-km resolution runs suggests a need for improvement of cumulus schemes, and supports the use of microphysics schemes in coarser

  13. Improved Subseasonal Prediction with Advanced Coupled Models including the 30km FIM-HYCOM Coupled Model

    Science.gov (United States)

    Benjamin, Stan; Sun, Shan; Grell, Georg; Green, Benjamin; Bleck, Rainer; Li, Haiqin

    2017-04-01

    Extreme events for subseasonal duration have been linked to multi-week processes related to onset, duration, and cessation of blocking events or, more generally, quasi-stationary waves. Results will be shown from different sets of 32-day prediction experiments (3200 runs each) over a 16-year period for earth system processes key for subseasonal prediction for different resolution, numerics, and physics using the FIM-HYCOM coupled model. The coupled atmosphere (FIM) and ocean (HYCOM) modeling system is a relatively new coupled atmosphere-ocean model developed for subseasonal to seasonal prediction (Green et al. 2017 Mon.Wea.Rev. accepted, Bleck et al 2015 Mon. Wea. Rev.). Both component models operate on a common icosahedral horizontal grid and use an adaptive hybrid vertical coordinate (sigma-isentropic in FIM and sigma-isopycnic in HYCOM). FIM-HYCOM has been used to conduct 16 years of subseasonal retrospective forecasts following the NOAA Subseasonal (SubX) NMME protocol (32-day forward integrations), run with 4 ensemble members per week. Results from this multi-year FIM-HYCOM hindcast include successful forecasts out to 14-20 days for stratospheric warming events (from archived 10 hPa fields), improved MJO predictability (Green et al. 2017) using the Grell-Freitas (2014, ACP) scale-aware cumulus scheme instead of the Simplified Arakawa-Schubert scheme, and little sensitivity to resolution for blocking frequency. Forecast skill of metrics from FIM-HYCOM including 500 hPa heights and MJO index is at least comparable to that of the operational Climate Forecast System (CFSv2) used by the National Centers for Environmental Prediction. Subseasonal skill is improved with a limited multi-model (FIM-HYCOM and CFSv2), consistent with previous seasonal multi-model ensemble results. Ongoing work will also be reported on for adding inline aerosol/chemistry treatment to the coupled FIM-HYCOM model and for advanced approaches to subgrid-scale clouds to address regional biases

  14. Rezension: Freie Bildungsmedien und Digitale Archive: Medien – Wissen – Bildung von Petra Missomelius, Wolfgang Sützl. Theo Hug, Petra Grell, Rudolf Kammerl (Hg.

    Directory of Open Access Journals (Sweden)

    Christian Berger

    2014-12-01

    Full Text Available Christian Berger hat für uns den soeben von unseren Innsbrucker medienpädagogischen KollegInnen herausgegebenen Band 'Freie Bildungsmedien und Digitale Archive: Medien – Wissen – Bildung' gelesen und rezensiert hiermit für die LeserInnen der MEDIENIMPULSE ...

  15. Evaluation of a regional climate model for atmospheric simulation over Arctic river basins

    Institute of Scientific and Technical Information of China (English)

    MA Yan; CHEN Shang; HUA Feng; WEI Helin; D. H. BROMWICH

    2008-01-01

    Evaluation on a regional climate model was made with five-month atmospheric simulations over the Arctic river basins. The simulations were performed with a modified mesoscale model, Polar MM5 coupled to the NCAR Land Surface Model (LSM) to illustrate the skill of the coupled model (Polar MM5+LSM) in simulating atmospheric circulation over the Arctic river basins. Near-surface and upper-air observations were used to verify the simulations. Sensitivity studies between the Polar MM5 and Polar MMS+LSM simulations revealed that the coupled model could improve the forecast skill for surface variables at some sites. In addition, the extended evaluations of the coupled model simulations on the North American Arctic domain during December 15, 2002 to May 15, 2003 were carded out. The time series plots and statistics of the observations and Polar MM5+LSM simulations at six stations for near-surface and vertical profiles at 850 hPa and 500 hPa were analyzed. The model was found capable of reproducing the observed atmospheric behavior in both magnitude and variability, especially for temperature and near-surface wind direction.

  16. An air quality model for Central Mexico

    Energy Technology Data Exchange (ETDEWEB)

    Jazcilevich, D. Aron; Garcia, R. Agustin; Suarez, Gerardo Ruiz; Magana, R. Victor; Perez, L. Jose Luis [Universidad Nacional Autonoma de Mexico, Centro de Ciencias de la Atmosfera, Mexico City (Mexico); Fuentes-Gea, Vicente [Universidad Nacional Autonoma de Mexico, Div. de Estudios del Posgrado, Mexico City (Mexico)

    1999-07-01

    A computational air quality model for Central Mexico that includes the Basin of the Valley of Mexico, the Valleys of Toluca, Puebla and Cuernavaca already in experimental operation, is presented. The meteorology of the region is obtained combining two non-hydrostatic models: a model designed for synoptic scales called MM5 provides initial and boundary data to a model specially designed for urban environments and scales called MEMO. The transport model used numerical techniques developed by the authors that eliminate numerical diffusion and dispersion. For the photochemical model several ODE's integrators were tested. The emissions model developed uses the latest inventory data gathered in the region. (Author)

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

    Energy Technology Data Exchange (ETDEWEB)

    Seaman, N.L.; Guo, Z.; Ackerman, T.P. [Pennsylvania State Univ., University Park, PA (United States)

    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.

  18. Influence of global changes on modeled ozone response to changes in local emissions and the policy implications for ozone abatement strategies in the US

    Science.gov (United States)

    Avise, J. C.; Gonzalez Abraham, R.; Chung, S. H.; Lamb, B. K.; Salathe, E. P.; Zhang, Y.; Streets, D. G.; Nolte, C. G.; Loughlin, D.; Guenther, A. B.; Wiedinmyer, C.; Duhl, T.; Chen, J.

    2010-12-01

    As part of an ongoing analysis on the effects of global changes upon US air quality, we report results based upon the WRF/CMAQ and MM5/CMAQ modeling frameworks in terms of the effect that future climate (including associated sensitivities with land use and biogenic emissions) and future global emissions have on the sensitivity of modeled ozone response to US anthropogenic emissions changes. Results are presented in a manner that is consistent with the current use of models in the development of State Implementation Plans (SIP) to highlight the importance for regulators of evaluating the impact that global changes may have on the successfulness of regulatory policies. Results are based on representative years within a current decade (1990-1999 for MM5/CMAQ and 1995-2004 for WRF/CMAQ) and a future decade (2045-2054). Meteorological fields for the CMAQ simulations were obtained by downscaling results from the ECHAM5 and PCM global climate models using WRF and MM5, respectively. The future climate is based on the Intergovernmental Panel for Climate Change (IPCC) A1B scenario (ECHAM5) and A2 scenario (PCM). The WRF and MM5 meteorology were used to drive the MEGAN biogenic emissions model, the SMOKE emissions processing system, and the CMAQ chemical transport model. WRF/CMAQ simulations were conducted on two nested domains covering most of the Northern Hemisphere from eastern Asia to North America (220-km horizontal resolution; hemispheric domain) and covering the continental US (36-km horizontal resolution; CONUS domain), while MM5/CMAQ simulations were conducted for the continental US only. Chemical boundary conditions for CONUS are modified to study the impact of global emissions changes. Future chemical boundary conditions for the WRF/CMAQ CONUS simulations were taken from results of the hemispheric simulations with global emissions based on IPCC A1B scenario; for the MM5/CMAQ simulations they were derived from results of the global chemical transport model MOZART

  19. Representation of monsoon intraseasonal oscillations in regional climate model: sensitivity to convective physics

    KAUST Repository

    Umakanth, U.

    2015-11-07

    The aim of the study is to evaluate the performance of regional climate model (RegCM) version 4.4 over south Asian CORDEX domain to simulate seasonal mean and monsoon intraseasonal oscillations (MISOs) during Indian summer monsoon. Three combinations of Grell (G) and Emanuel (E) cumulus schemes namely, RegCM-EG, RegCM-EE and RegCM-GE have been used. The model is initialized at 1st January, 2000 for a 13-year continuous simulation at a spatial resolution of 50 km. The models reasonably simulate the seasonal mean low level wind pattern though they differ in simulating mean precipitation pattern. All models produce dry bias in precipitation over Indian land region except in RegCM-EG where relatively low value of dry bias is observed. On seasonal scale, the performance of RegCM-EG is more close to observation though it fails at intraseasonal time scales. In wave number-frequency spectrum, the observed peak in zonal wind (850 hPa) at 40–50 day scale is captured by all models with a slight change in amplitude, however, the 40–50 day peak in precipitation is completely absent in RegCM-EG. The space–time characteristics of MISOs are well captured by RegCM-EE over RegCM-GE, however it fails to show the eastward propagation of the convection across the Maritime Continent. Except RegCM-EE all other models completely underestimates the moisture advection from Equatorial Indian Ocean onto Indian land region during life-cycle of MISOs. The characteristics of MISOs are studied for strong (SM) and weak (WM) monsoon years and the differences in model performances are analyzed. The wavelet spectrum of rainfall over central India denotes that, the SM years are dominated by high frequency oscillations (period <20 days) whereas little higher periods (>30 days) along with dominated low periods (<20 days) observed during WM years. During SM, RegCM-EE is dominated with high frequency oscillations (period <20 days) whereas in WM, RegCM-EE is dominated with periods >20

  20. Representation of monsoon intraseasonal oscillations in regional climate model: sensitivity to convective physics

    Science.gov (United States)

    Umakanth, U.; Kesarkar, Amit P.; Raju, Attada; Vijaya Bhaskar Rao, S.

    2016-08-01

    The aim of the study is to evaluate the performance of regional climate model (RegCM) version 4.4 over south Asian CORDEX domain to simulate seasonal mean and monsoon intraseasonal oscillations (MISOs) during Indian summer monsoon. Three combinations of Grell (G) and Emanuel (E) cumulus schemes namely, RegCM-EG, RegCM-EE and RegCM-GE have been used. The model is initialized at 1st January, 2000 for a 13-year continuous simulation at a spatial resolution of 50 km. The models reasonably simulate the seasonal mean low level wind pattern though they differ in simulating mean precipitation pattern. All models produce dry bias in precipitation over Indian land region except in RegCM-EG where relatively low value of dry bias is observed. On seasonal scale, the performance of RegCM-EG is more close to observation though it fails at intraseasonal time scales. In wave number-frequency spectrum, the observed peak in zonal wind (850 hPa) at 40-50 day scale is captured by all models with a slight change in amplitude, however, the 40-50 day peak in precipitation is completely absent in RegCM-EG. The space-time characteristics of MISOs are well captured by RegCM-EE over RegCM-GE, however it fails to show the eastward propagation of the convection across the Maritime Continent. Except RegCM-EE all other models completely underestimates the moisture advection from Equatorial Indian Ocean onto Indian land region during life-cycle of MISOs. The characteristics of MISOs are studied for strong (SM) and weak (WM) monsoon years and the differences in model performances are analyzed. The wavelet spectrum of rainfall over central India denotes that, the SM years are dominated by high frequency oscillations (period 30 days) along with dominated low periods (20 days. Except RegCM-EE, all other models fail to capture the observed spectral features for SM and WM years.

  1. Investigating Surface Bias Errors in the Weather Research and Forecasting (WRF) Model using a Geographic Information System (GIS)

    Science.gov (United States)

    2015-02-01

    horizontal grid spacing inner domain centered near San Diego, California. The San Diego area contains a mixture of urban , suburban, agricultural, and...Global Forecast System (GFS) model (Environmental Modeling Center 2003). The WRE–N is envisioned to be a rapid-update cycling application of WRF–ARW...surface– hydrology model with the Penn State-NCAR MM5 modeling system. Part I: Model implementation and sensitivity. Monthly Weather Review. 2001a

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

    NARCIS (Netherlands)

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

    2010-01-01

    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

  3. The Great African Plume from biomass burning: Generalizations from a three-dimensional study of TRACE A carbon monoxide

    Science.gov (United States)

    Chatfield, R. B.; Vastano, J. A.; Li, L.; Sachse, G. W.; Connors, V. S.

    1998-11-01

    The "Great African Plume" flows westward from a wind divergence line over Central Africa to pollute the Equatorial Atlantic Ocean. The plume arises from agricultural burning fumes which mix in a 3-4 km deep boundary layer over Africa, then override cooler rainforest air, and finally swerve westward, where their progress into the Atlantic is "gated" by southern storm systems. Another prominent elevated "Global Burning Plume" from Tropical South America flows past South Africa above 8 km altitude. Joining elevated African plumes, it influences the South Indian and Southern Oceans. These are results from our GRACES (Global Regional Atmospheric Chemistry Event Simulator), which was used to study carbon monoxide during an intensive experimental period, September-October 1992. Traces of the plumes are also evident in observations of CO in the Measurement of Air Pollution from Satellites (MAPS) samples of October, 1994, suggesting a general phenomena. To arrive at these conclusions, we used the detailed weather reconstructions afforded by MM5 meteorological model dynamics to drive GRACES. Both statistical and detailed (event) comparisons of CO and observed aboard the NASA DC-8 are good, especially <6 km altitude. The following model adaptations that we required may inform global analysis and global models: (1) Parameterized vertical transport like planetary boundary layer convection and deep cumulonimbus convection strongly control CO, allowing far more precision than trajectory studies and models using only large-scale motions. (2) CO sources during this period were consistent with the Hao and Liu [1994] report-based carbon-burn rates; (3) deep convection is even more active than as parameterized by MM5's Grell-scheme: on the large scale: mass fluxes effective for CO redistribution may be over twice core-updraft values diagnosed strengths.

  4. Aerosol effects and variable-resolution modelling approaches in regional climate applications

    Science.gov (United States)

    Heinzeller, D.; Junkermann, W.; Duda, M.; Kunstmann, H.

    2016-12-01

    Advances in numerical weather prediction and climate models and in computational facilities open the door to convection-resolving studies at regional and global scale. They also allow to include a range of important physical and chemical processes hitherto out of reach in a climate modelling context. In this contribution, we present two approaches that demonstrate achievements made in this area. First, we highlight the importance of aerosol effects in a regional climate study over South-Western Australia. While the entire region experienced a gradual decline in precipitation of about 15% over the 20th century, the coastal area around Perth saw an additional, sudden drop of the same order in the 1970s. Using the Weather and Research Forecasting tool WRF with a newly added, aerosol-aware microphysics scheme (Thompson and Eidhammer, 2014), we conduct a series of convection-resolving modelling experiments at a resolution of 3.3km for the period 1970-1974. We show that aerosol emissions of local large pollutants such as coal power plants and refineries, commissioned nearby during that period, can lead to a reduction in precipitation of up to 10%. The figure displays the resulting CCN number concentrations for three different aerosol-aware modelling experiments for the wet and dry season (i.e. austral winter and summer) 1970-1974 with surface wind vectors overlaid on top: standard aerosol concentrations (wrf-aero), tripled aerosol concentrations at every grid point (wrf-aerox3), and standard aerosol concentrations plus emissions from Muja Power Station (white dot). Second, we investigate the potential of variable-resolution modelling approaches in climate applications using the Model for Prediction Across Scales (MPAS). We perform a series of short-term experiments on two irregular meshes, employing an aerosol- and scale-aware convection scheme (Grell and Freitas, 2014), with focus on the representation of particular synoptic situations over Europe at a regionally

  5. Modelled long term trends of surface ozone over South Africa

    CSIR Research Space (South Africa)

    Naidoo, M

    2011-09-01

    Full Text Available /CAMx CAMx in NRE MM5 Past Future ? Retrospective Air quality ? CSIR 2010 Slide 5 New framework for air quality forecast ? CCAM/CAMx CAMx in NRE CCAM Past Future Future Air quality ? CSIR 2010 Slide 6 New research - air quality forecast... Current research focus ? The response of air quality to changes in climate ? Simulations on longer time scales ? Drive air quality models with long term forecasted meteorology ? Need a baseline (1989 ? 2009) ? To date: Initial testing and 2 years...

  6. IDD and mesoscale model integrated system IDD y el sistema integrado del modelo de mesoescala

    Directory of Open Access Journals (Sweden)

    Lia Martins Costa do Amaral

    2011-12-01

    Full Text Available As part of the group of research institutions and universities participating in the UNIDATA program, the Federal University of Pelotas (RS-Brazil has implemented an automatic data acquisition with forecasting and synoptic analysis system. It is based on the data distribution system (IDD of the UNIDATA (University Data Project and uses the Local Data Management module (LDM. This is an integrated system which has been primarily implemented to use the GFS/NCEP global forecasting model data for the processing of the regional MM5 mesoscale model, providing the necessary initial and lateral boundary conditions data. The MM5 has been configured to provide the forecast of the mesoscale systems over the State of Rio Grande do Sul (RS. The use of the data and model integrated system contributes to improve the skill analysis of the model output, aiming to investigate the benefits of its association in the evaluation of the performance of the integrated system.

  7. A hybrid numerical prediction scheme for solar radiation estimation in un-gauged catchments.

    Science.gov (United States)

    Shamim, M. A.; Bray, M.; Ishak, A. M.; Remesan, R.; Han, D.

    2009-09-01

    The importance of solar radiation on earth's surface is depicted in its wide range of applications in the fields of meteorology, agricultural sciences, engineering, hydrology, crop water requirements, climatic changes and energy assessment. It is quite random in nature as it has to go through different processes of assimilation and dispersion while on its way to earth. Compared to other meteorological parameters, solar radiation is quite infrequently measured, for example, the worldwide ratio of stations collecting solar radiation to those collecting temperature is 1:500 (Badescu, 2008). Researchers, therefore, have to rely on indirect techniques of estimation that include nonlinear models, artificial intelligence (e.g. neural networks), remote sensing and numerical weather predictions (NWP). This study proposes a hybrid numerical prediction scheme for solar radiation estimation in un-gauged catchments. It uses the PSU/NCAR's Mesoscale Modelling system (MM5) (Grell et al., 1995) to parameterise the cloud effect on extraterrestrial radiation by dividing the atmosphere into four layers of very high (6-12 km), high (3-6 km), medium (1.5-3) and low (0-1.5) altitudes from earth. It is believed that various cloud forms exist within each of these layers. An hourly time series of upper air pressure and relative humidity data sets corresponding to all of these layers is determined for the Brue catchment, southwest UK, using MM5. Cloud Index (CI) was then determined using (Yang and Koike, 2002): 1 p?bi [ (Rh - Rh )] ci =------- max 0.0,---------cri dp pbi - ptipti (1- Rhcri) where, pbi and pti represent the air pressure at the top and bottom of each layer and Rhcri is the critical value of relative humidity at which a certain cloud type is formed. Output from a global clear sky solar radiation model (MRM v-5) (Kambezidis and Psiloglu, 2008) is used along with meteorological datasets of temperature and precipitation and astronomical information. The analysis is aided by the

  8. Models

    DEFF Research Database (Denmark)

    Juel-Christiansen, Carsten

    2005-01-01

    Artiklen fremhæver den visuelle rotation - billeder, tegninger, modeller, værker - som det privilligerede medium i kommunikationen af ideer imellem skabende arkitekter......Artiklen fremhæver den visuelle rotation - billeder, tegninger, modeller, værker - som det privilligerede medium i kommunikationen af ideer imellem skabende arkitekter...

  9. High resolution modelling of snow transport in complex terrain using simulated wind fields

    Directory of Open Access Journals (Sweden)

    M. Bernhardt

    2008-07-01

    Full Text Available Snow transport is one of the most dominant processes influencing the snow cover accumulation and ablation in high alpine mountain environments. Hence, the spatial and temporal variability of the snow cover is significantly modified with respective consequences on the total amount of water in the snow pack, on the temporal dynamics of the runoff and on the energy balance of the surface. For the presented study we used the snow transport model SnowTran-3D in combination with MM5 (Penn State University – National Center for Atmospheric Research MM5 model generated wind fields. In a first step the MM5 wind fields were downscaled by using a semi-empirical approach which accounts for the elevation difference of model and real topography, as well as aspect, inclination and vegetation. The target resolution of 30 m corresponds to the resolution of the best available DEM and land cover map. For the numerical modelling, data of six automatic meteorological stations were used, comprising the winter season (September–August of 2003/04 and 2004/05. In addition we had automatic snow depth measurements and periodic manual measurements of snow courses available for the validation of the results. In this paper we describe the downscaling of the wind fields and discuss the results of the snow transport simulations with respect to the measurements and remotely sensed data.

  10. Assessing the value of increased model resolution in forecasting fire danger

    Science.gov (United States)

    Jeanne Hoadley; Miriam Rorig; Ken Westrick; Larry Bradshaw; Sue Ferguson; Scott Goodrick; Paul Werth

    2003-01-01

    The fire season of 2000 was used as a case study to assess the value of increasing mesoscale model resolution for fire weather and fire danger forecasting. With a domain centered on Western Montana and Northern Idaho, MM5 simulations were run at 36, 12, and 4-km resolutions for a 30 day period at the height of the fire season. Verification analyses for meteorological...

  11. Modelling

    CERN Document Server

    Spädtke, P

    2013-01-01

    Modeling of technical machines became a standard technique since computer became powerful enough to handle the amount of data relevant to the specific system. Simulation of an existing physical device requires the knowledge of all relevant quantities. Electric fields given by the surrounding boundary as well as magnetic fields caused by coils or permanent magnets have to be known. Internal sources for both fields are sometimes taken into account, such as space charge forces or the internal magnetic field of a moving bunch of charged particles. Used solver routines are briefly described and some bench-marking is shown to estimate necessary computing times for different problems. Different types of charged particle sources will be shown together with a suitable model to describe the physical model. Electron guns are covered as well as different ion sources (volume ion sources, laser ion sources, Penning ion sources, electron resonance ion sources, and H$^-$-sources) together with some remarks on beam transport.

  12. model

    African Journals Online (AJOL)

    trie neural construction oí inoiviouo! unci communal identities in ... occurs, Including models based on Information processing,1 ... Applying the DSM descriptive approach to dissociation in the ... a personal, narrative path lhal connects personal lo ethnic ..... managed the problem in the context of the community, using a.

  13. Sensitivity of hurricane track to cumulus parameterization schemes in the WRF model for three intense tropical cyclones: impact of convective asymmetry

    Science.gov (United States)

    Shepherd, Tristan J.; Walsh, Kevin J.

    2017-08-01

    This study investigates the effect of the choice of convective parameterization (CP) scheme on the simulated tracks of three intense tropical cyclones (TCs), using the Weather Research and Forecasting (WRF) model. We focus on diagnosing the competing influences of large-scale steering flow, beta drift and convectively induced changes in track, as represented by four different CP schemes (Kain-Fritsch (KF), Betts-Miller-Janjic (BMJ), Grell-3D (G-3), and the Tiedtke (TD) scheme). The sensitivity of the results to initial conditions, model domain size and shallow convection is also tested. We employ a diagnostic technique by Chan et al. (J Atmos Sci 59:1317-1336, 2002) that separates the influence of the large-scale steering flow, beta drift and the modifications of the steering flow by the storm-scale convection. The combined effect of the steering flow and the beta drift causes TCs typically to move in the direction of the wavenumber-1 (WN-1) cyclonic potential vorticity tendency (PVT). In instances of asymmetrical TCs, the simulated TC motion does not necessarily match the motion expected from the WN-1 PVT due to changes in the convective pattern. In the present study, we test this concept in the WRF simulations and investigate whether if the diagnosed motion from the WN-1 PVT and the TC motion do not match, this can be related to the emerging evolution of changes in convective structure. Several systematic results are found across the three cyclone cases. The sensitivity of TC track to initial conditions (the initialisation time and model domain size) is less than the sensitivity of TC track to changing the CP scheme. The simulated track is not overly sensitive to shallow convection in the KF, BMJ, and TD schemes, compared to the track difference between CP schemes. The G3 scheme, however, is highly sensitive to shallow convection being used. Furthermore, while agreement between the simulated TC track direction and the WN-1 diagnostic is usually good, there are

  14. Sensitivity of hurricane track to cumulus parameterization schemes in the WRF model for three intense tropical cyclones: impact of convective asymmetry

    Science.gov (United States)

    Shepherd, Tristan J.; Walsh, Kevin J.

    2016-08-01

    This study investigates the effect of the choice of convective parameterization (CP) scheme on the simulated tracks of three intense tropical cyclones (TCs), using the Weather Research and Forecasting (WRF) model. We focus on diagnosing the competing influences of large-scale steering flow, beta drift and convectively induced changes in track, as represented by four different CP schemes (Kain-Fritsch (KF), Betts-Miller-Janjic (BMJ), Grell-3D (G-3), and the Tiedtke (TD) scheme). The sensitivity of the results to initial conditions, model domain size and shallow convection is also tested. We employ a diagnostic technique by Chan et al. (J Atmos Sci 59:1317-1336, 2002) that separates the influence of the large-scale steering flow, beta drift and the modifications of the steering flow by the storm-scale convection. The combined effect of the steering flow and the beta drift causes TCs typically to move in the direction of the wavenumber-1 (WN-1) cyclonic potential vorticity tendency (PVT). In instances of asymmetrical TCs, the simulated TC motion does not necessarily match the motion expected from the WN-1 PVT due to changes in the convective pattern. In the present study, we test this concept in the WRF simulations and investigate whether if the diagnosed motion from the WN-1 PVT and the TC motion do not match, this can be related to the emerging evolution of changes in convective structure. Several systematic results are found across the three cyclone cases. The sensitivity of TC track to initial conditions (the initialisation time and model domain size) is less than the sensitivity of TC track to changing the CP scheme. The simulated track is not overly sensitive to shallow convection in the KF, BMJ, and TD schemes, compared to the track difference between CP schemes. The G3 scheme, however, is highly sensitive to shallow convection being used. Furthermore, while agreement between the simulated TC track direction and the WN-1 diagnostic is usually good, there are

  15. Skills of different mesoscale models over Indian region during monsoon season: Forecast errors

    Indian Academy of Sciences (India)

    Someshwar Das; Raghavendra Ashrit; Gopal Raman Iyengar; Saji Mohandas; M Das Gupta; John P George; E N Rajagopal; Surya Kanti Dutta

    2008-10-01

    Performance of four mesoscale models namely,the MM5,ETA,RSM and WRF,run at NCMRWF for short range weather forecasting has been examined during monsoon-2006.Evaluation is carried out based upon comparisons between observations and day-1 and day-3 forecasts of wind,temperature,specific humidity,geopotential height,rainfall,systematic errors,root mean square errors and specific events like the monsoon depressions. It is very difficult to address the question of which model performs best over the Indian region? An honest answer is ‘none ’.Perhaps an ensemble approach would be the best.However, if we must make a final verdict,it can be stated that in general,(i)the WRF is able to produce best All India rainfall prediction compared to observations in the day-1 forecast and,the MM5 is able to produce best All India rainfall forecasts in day-3,but ETA and RSM are able to depict the best distribution of rainfall maxima along the west coast of India,(ii)the MM5 is able to produce least RMSE of wind and geopotential fields at most of the time,and (iii)the RSM is able to produce least errors in the day-1 forecasts of the tracks,while the ETA model produces least errors in the day-3 forecasts.

  16. Hybridizing the fifth generation mesoscale model with artificial neural networks for short-term wind speed prediction

    Energy Technology Data Exchange (ETDEWEB)

    Salcedo-Sanz, Sancho; Perez-Bellido, Angel M.; Ortiz-Garcia, Emilio G.; Portilla-Figueras, Antonio [Department of Signal Theory and Communications, Universidad de Alcala, Madrid (Spain); Prieto, Luis [Wind Resource Department, Iberdrola Renovables, Madrid (Spain); Paredes, Daniel [Department of Physics of the Earth, Astronomy and Astrophysics II, Universidad Complutense de Madrid (Spain)

    2009-06-15

    This paper presents the hybridization of the fifth generation mesoscale model (MM5) with neural networks in order to tackle a problem of short-term wind speed prediction. The mean hourly wind speed forecast at wind turbines in a wind park is an important parameter used to predict the total power production of the park. Our model for short-term wind speed forecast integrates a global numerical weather prediction model and observations at different heights (using atmospheric soundings) as initial and boundary conditions for the MM5 model. Then, the outputs of this model are processed using a neural network to obtain the wind speed forecast in specific points of the wind park. In the experiments carried out, we present some results of wind speed forecasting in a wind park located at the south-east of Spain. The results are encouraging, and show that our hybrid MM5-neural network approach is able to obtain good short-term predictions of wind speed at specific points. (author)

  17. Modelling of the plasma-MIG welding temperature field

    Institute of Scientific and Technical Information of China (English)

    Bai Yan; Gao Hongming; Wu Lin; Shi Lei

    2006-01-01

    A three-dimensional simulation model for the plasma-MIG welding process, which takes the interaction between the plasma arc and MIG arc into account, is presented and the quasi-steady temperature fields on the workpiece are calculated with the model. The 10 mm-5A06 aluminum alloy is welded and the temperature fields are measured with the thermoelectric couple. The simulation results and measured results show that the biggest deviation of peak temperature between them is below 20 ℃ , which indicates good coincidence between the simulation and measurement.

  18. Combined Microwave and Sferics Measurements as a Continuous Proxy for Latent Heating in Mesoscale Model Predictions

    Science.gov (United States)

    Chang, D. -E.; Morales, C. A.; Weinman, J. A.; Olson, W. S.

    1999-01-01

    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 Mesoscale Model (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.

  19. Impact of vegetation on the simulation of seasonal monsoon rainfall over the Indian subcontinent using a regional model

    Indian Academy of Sciences (India)

    Surya K Dutta; Someshwar Das; S C Kar; U C Mohanty; P C Joshi

    2009-10-01

    The change in the type of vegetation fraction can induce major changes in the local effects such as local evaporation,surface radiation,etc.,that in turn induces changes in the model simulated outputs.The present study deals with the effects of vegetation in climate modeling over the Indian region using the MM5 mesoscale model.The main objective of the present study is to investigate the impact of vegetation dataset derived from SPOT satellite by ISRO (Indian Space Research Organization)versus that of USGS (United States Geological Survey)vegetation dataset on the simulation of the Indian summer monsoon.The present study has been conducted for five monsoon seasons (1998 –2002),giving emphasis over the two contrasting southwest monsoon seasons of 1998 (normal)and 2002 (deficient). The study reveals mixed results on the impact of vegetation datasets generated by ISRO and USGS on the simulations of the monsoon.Results indicate that the ISRO data has a positive impact on the simulations of the monsoon over northeastern India and along the western coast.The MM5- USGS has greater tendency of overestimation of rainfall.It has higher standard deviation indicating that it induces a dispersive effect on the rainfall simulation.Among the five years of study,it is seen that the RMSE of July and JJAS (June –July –August –September)for All India Rainfall is mostly lower for MM5-ISRO.Also,the bias of July and JJAS rainfall is mostly closer to unity for MM5-ISRO.The wind fields at 850 hPa and 200 hPa are also better simulated by MM5 using ISRO vegetation.The synoptic features like Somali jet and Tibetan anticyclone are simulated closer to the veri fication analysis by ISRO vegetation.The 2 m air temperature is also better simulated by ISRO vegetation over the northeastern India,showing greater spatial variability over the region. However,the JJAS total rainfall over north India and Deccan coast is better simulated using the USGS vegetation.Sensible heat flux over

  20. A study of dispersion in complex terrain under winter conditions using high-resolution mesoscale and Lagrangian particle models

    Directory of Open Access Journals (Sweden)

    J. L. Palau

    2005-11-01

    Full Text Available A mesoscale model (MM5, a dispersive Langrangian particle model (FLEXPART, and intensive meteorological and COrrelation SPECtrometer (COSPEC measurements from a field campaign are used to examine the advection and turbulent diffusion patterns associated with interactions and forcings between topography, synoptic atmospheric flows and thermally-driven circulations. This study describes the atmospheric dispersion of emissions from a power plant with a 343-meter-tall chimney, situated on very complex terrain in the North-East of Spain, under winter conditions. During the field campaign, the plume was transported with low transversal dispersion and deformed essentially due to the effect of mechanical turbulence. The main surface impacts appeared at long distances from the emission source (more than 30 km. The results show that the coupled models (MM5 and FLEXPART are able to predict the plume integral advection from the power plant on very complex terrain. Integral advection and turbulent dispersion are derived from the dispersive Lagrangian model output for three consecutive days so that a direct quantitative comparison has been made between the temporal evolution of the predicted three-dimensional dispersive conditions and the COSPEC measurements. Comparison between experimental and simulated transversal dispersion shows an index of agreement between 80% and 90%, within distance ranges from 6 to 33 km from the stack. Linked to the orographic features, the simulated plume impacts on the ground more than 30 km away from the stack, because of the lee waves simulated by MM5.

  1. Analysis of an extremely dense regional fog event in Eastern China using a mesoscale model

    Science.gov (United States)

    Shi, Chune; Yang, Jun; Qiu, Mingyan; Zhang, Hao; Zhang, Su; Li, Zihua

    2010-03-01

    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 mesoscale meteorological model (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.

  2. The hourly updated US High-Resolution Rapid Refresh (HRRR) storm-scale forecast model

    Science.gov (United States)

    Alexander, Curtis; Dowell, David; Benjamin, Stan; Weygandt, Stephen; Olson, Joseph; Kenyon, Jaymes; Grell, Georg; Smirnova, Tanya; Ladwig, Terra; Brown, John; James, Eric; Hu, Ming

    2016-04-01

    observations through the model boundary layer and (2) extending the use of radar observations to include both radial velocity and 3-D retrieval of rain hydrometeors from observed radar reflectivities in the warm-season. The RAP hybrid EnKF 3D-variational data assimilation will increase weighting of GFS ensemble-based background error covariance estimation and introduce this hybrid data assimilation configuration in the HRRR. Enhancement of RAP and HRRR model physics include improved land surface and boundary layer prediction using the updated Mellor-Yamada-Nakanishi-Niino (MYNN) parameterization scheme, Grell-Freitas-Olson (GFO) shallow and deep convective parameterization, aerosol-aware Thompson microphysics and upgraded Rapid Update Cycle (RUC) land-surface model. The presentation will highlight improvements in the RAP and HRRR model physics to reduce certain systematic forecast biases including a warm and dry daytime bias over the central and eastern CONUS during the warm season along with improved convective forecasts in more weakly-forced diurnally-driven events. Examples of RAP and HRRR forecast improvements will be demonstrated through both retrospective and real-time verification statistics and case-study examples.

  3. Air quality modeling in the Valley of Mexico: meteorology, emissions and forecasting

    Science.gov (United States)

    Garcia-Reynoso, A.; Jazcilevich, A. D.; Diaz-Nigenda, E.; Vazquez-Morales, W.; Torres-Jardon, R.; Ruiz-Suarez, G.; Tatarko, J.; Bornstein, R.

    2007-12-01

    The Valley of Mexico presents important challenges for air quality modeling: complex terrain, a great variety of anthropogenic and natural emissions sources, and high altitude and low latitude increasing the amount of radiation flux. The modeling group at the CCA-UNAM is using and merging state of the art models to study the different aspects that influence the air quality phenomenon in the Valley of Mexico. The air quality model MCCM that uses MM5 as its meteorological input has been a valuable tool to study important features of the complex and intricate atmospheric flows on the valley, such as local confluences and vertical fumigation. Air quality modeling has allowed studying the interaction between the atmospheres of the valleys surrounding the Valley of Mexico, prompting the location of measurement stations during the MILAGRO campaign. These measurements confirmed the modeling results and expanded our knowledge of the transport of pollutants between the Valleys of Cuernavaca, Puebla and Mexico. The urban landscape of Mexico City complicates meteorological modeling. Urban-MM5, a model that explicitly takes into account the influence of buildings, houses, streets, parks and anthropogenic heat, is being implemented. Preliminary results of urban-MM5 on a small area of the city have been obtained. The current emissions inventory uses traffic database that includes hourly vehicular activity in more than 11,000 street segments, includes 23 area emissions categories, more than 1,000 industrial sources and biogenic emissions. To improve mobile sources emissions a system consisting of a traffic model and a car simulator is underway. This system will allow for high time and space resolution and takes into account motor stress due to different driving regimes. An important source of emissions in the Valley of Mexico is erosion dust. The erosion model WEPS has been integrated with MM5 and preliminary results showing dust episodes over Mexico City have been obtained. A

  4. Air Quality Model System For The Vienna/bratislava Region

    Science.gov (United States)

    Krüger, B. C.; Schmittner, W.; Kromp-Kolb, H.

    A model system has been build up, consisting of the mesoscale meteorological fore- cast model MM5 and the chemical air-quality model CAMx. The coarse grid covers central Europe. By nesting, a spatial resolution of 3 km is reached for the core area, which includes the cities of Vienna (Austria) and Bratislava (Slovakia). In a first approach, the model system has been applied to a 6-day period in Febru- ary 1997, which was characterized by stagnant meteorological conditions. During this episode, primary pollutants like CO and NO2 have been compared with ambient mea- surements for the validation of the new model system. In the future it is foreseen to improve the spatial resolution, to apply the model system also for ozone and particulates, and to utilize it for a short-time forecast of air-quality parameters.

  5. Mudanças do esquema de convecção profunda Kain-Fritsch para a região do centro de lançamento de Alcântara Changes in the Kain-Fritsch convective parameterization deep scheme for the Alcântara launch center region

    Directory of Open Access Journals (Sweden)

    Antonio Vicente Pereira Neto

    2011-12-01

    Full Text Available Foram realizadas mudanças no esquema de parametrização convectiva de Kain-Fritsch (KF2, para melhor representar a precipitação na região do Centro de Lançamento de Alcântara (CLA em simulações com o modelo regional MM5. Simulações de 24 h em um domínio aproximadamente centrado no CLA, com espaçamento de grade de 30 km foram realizadas para o período de 2005-2006 (calibração e 2008 (validação. O KF2 foi modificado sob a seguinte configuração: passo de tempo de 60 s, uso do esquema de convecção explícita warm rain e uso conjunto dos esquemas de convecção rasa de Grell e do KF2. As mudanças no KF2 foram: aumento da profundidade de nuvem necessária para disparar a convecção profunda e ajuste de alguns parâmetros da função disparo da convecção dependentes da velocidade vertical ascendente na coluna atmosférica. Com as modificações, houve expressiva melhoria na representação do total de precipitação e da fração dos dias do mês com chuva na escala mensal. O padrão espacial de erros no domínio, no entanto, não sofreu muitas alterações sobre o continente (em geral, a precipitação foi melhor representada sobre o continente do que sobre o oceano. Todas as etapas de mudanças e ajustes realizadas no trabalho poderão ser empregadas para melhorar a representação da precipitação em outras regiões específicas.Changes in the Kain-Fritsch convective parameterization scheme (KF2 were included to better represent the precipitation in simulations using the MM5 regional model for the Alcântara Launch Center (CLA region. Daily (24 h integrations for a 30 km grid spacing domain centered in CLA were performed for 2005-2006 (calibration and 2008 (validation. KF2 scheme was modified under the following simulation settings: time step of 60 s, use of warm rain scheme and joint use of Grell and KF2 shallow convection schemes. Changes in KF2 were: increase of minimum cloud depth to initiate deep convection and

  6. Modelled surface ozone over southern africa during the cross border air pollution impact assessment project

    CSIR Research Space (South Africa)

    Zunckel, M

    2006-07-01

    Full Text Available .M.N., Pereira, J.M.C., Cabral, A.I., Sa, A.C.L., Vasconcelos, M.J.P., Mota, B., Gregoire, J.M., 2003. An estimate of area burned in southern Africa during the 2000 dry season using SPOT-VETETATION satellite data. Journal of Geophysical Re- search 108 (D13), 8498..., doi: 10.1029/202JD002325. Sokhi, R.S., San Jose, R., Kitwiroon, N., Fragkou, E., Peres, J.L., Middleton, D.R., Prediction of ozone levels in London using MM5eCMAQ modelling system. Environmental Modelling and Software, in press. doi: 10.1016/j...

  7. Numerical Modelling of Troposferic Ozone in Catalunya

    Directory of Open Access Journals (Sweden)

    S. Ortega

    2006-01-01

    Full Text Available The aim of this paper is to evaluate the ability of two different modelling systems to simulate high values of ozone concentration in typical summer episodes which take place in Catalonia, located in the north-east part of Spain. The first model, or forecasting system, is a box model made up of three modules. The first module is a mesoscale model (MASS, which provides the initial condition for the second module, a non-local boundary layer model based on the transilient turbulence scheme. The third module is a photochemical box model (OZIPR, which is applied in Eulerian and Lagrangian modes receiving suitable information from the two previous modules. The model forecast is applied to different areas of Catalonia and evaluated during the springs and summers of 2003 and 2004 against ground base stations. The second model is MM5/UAM-V, a grid model designed to predict the hourly three-dimensional ozone concentration fields. The model is applied during an ozone episode occurred between 21 and 23 June 2001 at only one area, which is characterized by complex topography and a peculiar meteorological condition favouring high ozone concentration values. Evaluation results and model comparison for this specific episode show a good performance of the two modelling systems.

  8. Application of the Physical Quantity Field Evolution under Numerical Model in Precipitation Forecast of Yantai

    Institute of Scientific and Technical Information of China (English)

    2011-01-01

    [Objective]The research aimed to understand role of the forecast data about physical quantity field in precipitation forecast.[Method] By contrasting forecast and actual situation of the precipitation in Yantai during 2-3 July and 12-15 September,2011,advantages and disadvantages of the different numerical forecast models (Japan fax chart,European center,MM5,Grapes and T639) were analyzed.[Result] MICAPS system could provide live situation of the physical quantity field,but couldn't provide the future evolu...

  9. Regional Scale/Regional Climate Model Development and Its Applications at Goddard

    Science.gov (United States)

    Tao, W.-K.; Lau, W.; Qian, J.; Jia, Y.; Wetzel, P.; Chou, M.-D.; Wang, Y.; Lynn, B.

    2000-01-01

    A Regional Land-Atmosphere Climate Simulation System (RELACS) is being developed and implemented at NASA Goddard Space Flight Center. One of the major goals of RELACS is to use a regional scale model (Penn State/NCAR MM5) with improved physical processes and in particular land-related processes, to understand the role of the land surface and its interaction with convection and radiation as well as the water/energy cycles in the Indo-China/South China Sea (SCS)/China, N. America and S. America region.

  10. Evaluating some indicators for identifying mountain waves situations in snow days by means of numerical modeling and continuous data

    Science.gov (United States)

    Sanchez, Jose Luis; Posada, Rafael; Hierro, Rodrigo; García-Ortega, Eduardo; Lopez, Laura; Gascón, Estibaliz

    2013-04-01

    Madrid - Barajas airport is placed at 70 km away from the Central System and snow days and mountains waves are considered as risks days for landing operations. This motivated the study of mesoscale factors affecting this type of situations. The availability of observational data gathered during three consecutives winter campaigns in the Central System along with data from high-resolution numerical models, have allowed the evaluation of the environmental conditions necessary for mountain waves formations in snow days and were characterized from observational data and numerical simulations. By means of Meteosat Second Generation satellite images, lee clouds were observed in 25 days corresponding to the 2008-2011 winter seasons. Six of them, which also presented NW low level flow over the mountain range, were analyzed. Necessary conditions for oscillations as well as vertical wave propagation were studied from radiometer data and MM5 model simulations. From radiometer data the presence of stable environment in the six selected events is confirmed. From MM5 model, dynamic conditions allowing the flow to cross the mountain range were evaluated in three different locations around the mountain range. Simulations of vertical velocity show that MM5 model is able to detect mountain waves. The waves present in the six selected events are examined. Tropospheric were able to forecast energy release associated with the mountain waves. The vertical wavelength presented a high variability due to intense background winds at high tropospheric levels. The average values estimated for λz were between 3 and 12 km. The intrinsic period estimated was around 30 and 12 km. The simulations were able to forecast energy release associated with mountain waves. Acknowledgments: This study was supported by the Plan Nacional de I+D of Spain, through the grants CGL2010-15930, Micrometeo IPT-310000-2010-022 and the Junta de Castilla y León through the grant LE220A11-2.

  11. Using Bayesian Model Averaging (BMA to calibrate probabilistic surface temperature forecasts over Iran

    Directory of Open Access Journals (Sweden)

    I. Soltanzadeh

    2011-07-01

    Full Text Available Using Bayesian Model Averaging (BMA, an attempt was made to obtain calibrated probabilistic numerical forecasts of 2-m temperature over Iran. The ensemble employs three limited area models (WRF, MM5 and HRM, with WRF used with five different configurations. Initial and boundary conditions for MM5 and WRF are obtained from the National Centers for Environmental Prediction (NCEP Global Forecast System (GFS and for HRM the initial and boundary conditions come from analysis of Global Model Europe (GME of the German Weather Service. The resulting ensemble of seven members was run for a period of 6 months (from December 2008 to May 2009 over Iran. The 48-h raw ensemble outputs were calibrated using BMA technique for 120 days using a 40 days training sample of forecasts and relative verification data.

    The calibrated probabilistic forecasts were assessed using rank histogram and attribute diagrams. Results showed that application of BMA improved the reliability of the raw ensemble. Using the weighted ensemble mean forecast as a deterministic forecast it was found that the deterministic-style BMA forecasts performed usually better than the best member's deterministic forecast.

  12. A Mesoscale Meteorological Model of Modified Land Cover to the Effect of Urban Heat Island in Jakarta, Indonesia

    Directory of Open Access Journals (Sweden)

    Yopi Ilhamsyah

    2012-08-01

    Full Text Available A mesoscale meteorological model of modified land cover to the effect of urban heat island (UHI in Jakarta was done. Although higher temperature in the city has been generally known, factors and issues that result in the increase of temperature particularly nighttime temperature over the city, however, are not well-understood. Jakarta, the capital of Indonesia, is encountering urbanization problems foremost. The increasing demand of housing as well as rapid development of sky crapper building, market places and highway diminishes the vegetation which in turn trap heat in the troposphere throughout the year, particularly during dry season on June-August. The fifth-generation mesoscale meteorological model (MM5 was employed in the study. The model involves medium range forecast planetary boundary layer (MRF PBL scheme and land surface with two following parameters: i.e. roughness length over land and thermal inertia of land. These two parameters are chosen to enhance the characteristics of land surface. The simulation was carried out for 3 days on August 5-7, 2004 during dry season. The results showed that the simulation of surface temperature done by MM5 modified land cover described a good comparison to that of weather observation data. As a result, the effect of UHI was also well-observed during day-time. In addition, MM5 modified land cover simulation also illustrated a well-development of sea-breeze and country-breeze during mid-day and nighttime, respectively. However, long-term simulation is still required. Thus, daily diurnal cycles of air temperature and their differences can be well-observed in detail.

  13. Study and case simulation of a regional dust model coupled with a nonhydrostatic dynamics model

    Institute of Scientific and Technical Information of China (English)

    CHENG Conglan; WANG Yingchun; LIU Weidong; ZHANG Xiaoling; XU Xiaofeng; XIE Pu

    2004-01-01

    A new regional dust model suitable for simulation and forecasting of dust storms over northern China was described. The dust model was developed by coupling the mesoscale dynamics model MM5 (the Fifth-Generation NCAR/Penn State Mesoscale Model) with a set of mass conservation equations for the particles. The model includes all the atmospheric physical processes of dust storms including occurrence, lifting, transport, and dry and wet deposition. It considers the parameterization of dry and wet deposition, the dust size distribution and microphysical processes in detail. The dust flux from the surface is parameterized based on the friction velocity, which is provided by the mesoscale nonhydrostatic dynamics model, which takes account of the vegetation coverage, land use, soil category, and soil moisture. This new dust model is used to simulate the dust storm that occurred on 19-21 March, 2002 in North China. The results show that there is high dust concentration and its movement is consistent with the surface weather record and satellite monitoring images of the observed dust storm. The simulated dust concentration coincides with the observation data of the particulate concentration of PM10 (dust particles smaller than 10 μm in diameter). The new numerical model also successfully simulates the formation and migration of the dust storm of 6-8 April, 2002 in North China.

  14. Linkage between an advanced air quality model and a mechanistic watershed model

    Directory of Open Access Journals (Sweden)

    K. Vijayaraghavan

    2010-09-01

    Full Text Available An offline linkage between two advanced multi-pollutant air quality and watershed models is presented. The models linked are (1 the Advanced Modeling System for Transport, Emissions, Reactions and Deposition of Atmospheric Matter (AMSTERDAM (a three-dimensional Eulerian plume-in-grid model derived from the Community Multiscale Air Quality (CMAQ model and (2 the Watershed Analysis Risk Management Framework (WARMF. The pollutants linked include gaseous and particulate nitrogen, sulfur and mercury compounds. The linkage may also be used to obtain meteorological fields such as precipitation and air temperature required by WARMF from the outputs of the meteorology chemistry interface processor (MCIP that processes meteorology simulated by the fifth generation Mesoscale Model (MM5 or the Weather Research and Forecast (WRF model for input to AMSTERDAM. The linkage is tested in the Catawba River basin of North and South Carolina for ammonium, nitrate and sulfate. Modeled air quality and meteorological fields transferred by the linkage can supplement the conventional measurements used to drive WARMF and may be used to help predict the impact of changes in atmospheric emissions on water quality.

  15. Linkage between an advanced air quality model and a mechanistic watershed model

    Science.gov (United States)

    Vijayaraghavan, K.; Herr, J.; Chen, S.-Y.; Knipping, E.

    2010-09-01

    An offline linkage between two advanced multi-pollutant air quality and watershed models is presented. The models linked are (1) the Advanced Modeling System for Transport, Emissions, Reactions and Deposition of Atmospheric Matter (AMSTERDAM) (a three-dimensional Eulerian plume-in-grid model derived from the Community Multiscale Air Quality (CMAQ) model) and (2) the Watershed Analysis Risk Management Framework (WARMF). The pollutants linked include gaseous and particulate nitrogen, sulfur and mercury compounds. The linkage may also be used to obtain meteorological fields such as precipitation and air temperature required by WARMF from the outputs of the meteorology chemistry interface processor (MCIP) that processes meteorology simulated by the fifth generation Mesoscale Model (MM5) or the Weather Research and Forecast (WRF) model for input to AMSTERDAM. The linkage is tested in the Catawba River basin of North and South Carolina for ammonium, nitrate and sulfate. Modeled air quality and meteorological fields transferred by the linkage can supplement the conventional measurements used to drive WARMF and may be used to help predict the impact of changes in atmospheric emissions on water quality.

  16. Modelling photochemistry in alpine valleys

    Directory of Open Access Journals (Sweden)

    G. Brulfert

    2005-01-01

    Full Text Available Road traffic is a serious problem in the Chamonix Valley, France: traffic, noise and above all air pollution worry the inhabitants. The big fire in the Mont-Blanc tunnel made it possible, in the framework of the POVA project (POllution in Alpine Valleys, to undertake measurement campaigns with and without heavy-vehicle traffic through the Chamonix and Maurienne valleys, towards Italy (before and after the tunnel re-opening. Modelling is one of the aspects of POVA and should make it possible to explain the processes leading to episodes of atmospheric pollution, both in summer and in winter. Atmospheric prediction model ARPS 4.5.2 (Advanced Regional Prediction System, developed at the CAPS (Center for Analysis and Prediction of Storms of the University of Oklahoma, enables to resolve the dynamics above a complex terrain. This model is coupled to the TAPOM 1.5.2 atmospheric chemistry (Transport and Air POllution Model code developed at the Air and Soil Pollution Laboratory of the Ecole Polytechnique Fédérale de Lausanne. The numerical codes MM5 and CHIMERE are used to compute large scale boundary forcing. This paper focuses on modelling Chamonix valley using 300-m grid cells to calculate the dynamics and the reactive chemistry which makes possible to accurately represent the dynamics in the Chamonix valley (slope and valley winds and to process chemistry at fine scale. The summer 2003 intensive campaign was used to validate the model and to study chemistry. NOy according to O3 reduction demonstrates a VOC controlled regime, different from the NOx controlled regime expected and observed in the nearby city of Grenoble.

  17. M/M/1/m系统算子的本征值特性(m=5,6)%The Characteristics of Eigenvalue of M/M/1/m(m =5,6)

    Institute of Scientific and Technical Information of China (English)

    盖平; 高超; 唐慧; 赵立杰

    2010-01-01

    研究了m=5,6时,M/M/1/m算子本征值特性:m=6时相应本征值的代数重为1;m=5,6时,相应的系统算子的非零本征值相互交替;m=6时的最大非零本征值比m=5时更靠近0点.这种特性延续了m=1,2,3,4,5时相应的特性.另外给出了m=5,6时,相应的po(t)图像.

  18. Evaluation of two ozone air quality modelling systems

    Directory of Open Access Journals (Sweden)

    S. Ortega

    2004-01-01

    Full Text Available The aim of this paper is to compare two different modelling systems and to evaluate their ability to simulate high values of ozone concentration in typical summer episodes which take place in the north of Spain near the metropolitan area of Barcelona. As the focus of the paper is the comparison of the two systems, we do not attempt to improve the agreement by adjusting the emission inventory or model parameters. The first model, or forecasting system, is made up of three modules. The first module is a mesoscale model (MASS. This provides the initial condition for the second module, which is a nonlocal boundary layer model based on the transilient turbulence scheme. The third module is a photochemical box model (OZIPR, which is applied in Eulerian and Lagrangian modes and receives suitable information from the two previous modules. The model forecast is evaluated against ground base stations during summer 2001. The second model is the MM5/UAM-V. This is a grid model designed to predict the hourly three-dimensional ozone concentration fields. The model is applied during an ozone episode that occurred between 21 and 23 June 2001. Our results reflect the good performance of the two modelling systems when they are used in a specific episode.

  19. Modeling and simulation of M/M/c queuing pharmacy system with adjustable parameters

    Science.gov (United States)

    Rashida, A. R.; Fadzli, Mohammad; Ibrahim, Safwati; Goh, Siti Rohana

    2016-02-01

    This paper studies a discrete event simulation (DES) as a computer based modelling that imitates a real system of pharmacy unit. M/M/c queuing theo is used to model and analyse the characteristic of queuing system at the pharmacy unit of Hospital Tuanku Fauziah, Kangar in Perlis, Malaysia. The input of this model is based on statistical data collected for 20 working days in June 2014. Currently, patient waiting time of pharmacy unit is more than 15 minutes. The actual operation of the pharmacy unit is a mixed queuing server with M/M/2 queuing model where the pharmacist is referred as the server parameters. DES approach and ProModel simulation software is used to simulate the queuing model and to propose the improvement for queuing system at this pharmacy system. Waiting time for each server is analysed and found out that Counter 3 and 4 has the highest waiting time which is 16.98 and 16.73 minutes. Three scenarios; M/M/3, M/M/4 and M/M/5 are simulated and waiting time for actual queuing model and experimental queuing model are compared. The simulation results show that by adding the server (pharmacist), it will reduce patient waiting time to a reasonable improvement. Almost 50% average patient waiting time is reduced when one pharmacist is added to the counter. However, it is not necessary to fully utilize all counters because eventhough M/M/4 and M/M/5 produced more reduction in patient waiting time, but it is ineffective since Counter 5 is rarely used.

  20. Modelling photochemistry in alpine valleys

    Directory of Open Access Journals (Sweden)

    G. Brulfert

    2005-03-01

    Full Text Available Road traffic is a serious problem in the Chamonix Valley, France: traffic, noise and above all air pollution worry the inhabitants. The big fire in the Mont-Blanc tunnel made it possible, in the framework of the POVA project (POllution in Alpine Valleys, to undertake measurement campaigns with and without heavy-vehicle traffic through the valley, towards Italy (before and after the tunnel re-opening. Modelling in POVA should make it possible to explain the processes leading to episodes of atmospheric pollution, both in summer and in winter.

    Atmospheric prediction model ARPS 4.5.2 (Advanced Regional Prediction System, developed at the CAPS (Center for Analysis and Prediction of Storms of the University of Oklahoma, enables to resolve the dynamics above a complex terrain.

    This model is coupled to the TAPOM 1.5.2 atmospheric chemistry (Transport and Air POllution Model code developed at the Air and Soil Pollution Laboratory of the Ecole Polytechnique Fédérale de Lausanne.

    The numerical codes MM5 and CHIMERE are used to compute large scale boundary forcing.

    Using 300-m grid cells to calculate the dynamics and the reactive chemistry makes possible to accurately represent the dynamics in the valley (slope and valley winds and to process chemistry at fine scale.

    Validation of campaign days allows to study chemistry indicators in the valley. NOy according to O3 reduction demonstrates a VOC controlled regime, different from the NOx controlled regime expected and observed in the nearby city of Grenoble.

  1. Evaluating CloudSat Ice Water Retrievals Using a Cloud Resolving Model: Sensitivities to Frozen Particle Properties and Implications for Model-Data Comparisons

    Science.gov (United States)

    Woods, C. P.; Waliser, D.; Li, F.; Austin, R.; Stephens, G.; Vane, D.; Tao, W.; Tompkins, A.

    2007-12-01

    The sensitivities of CloudSat ice water content retrievals to frozen particle characteristics are tested by generating CloudSat-like retrievals from profiles of known ice water content. First, `truth' values of total ice water content are generated by a cloud-resolving model (MM5). The MM5 model profiles are generated using the Reisner- Thompson microphysical parameterization scheme, which allows for the existence of multiple types of frozen particles (cloud ice, snow and graupel). Next, a 94-GHz reflectivity simulator, called QuickBeam, is used to generate a CloudSat-like view of the model generated profiles. Since reflectivity is highly dependent on the characteristics of the scattering particles (e.g., density, size distribution), a set of tests are performed to determine the sensitivity of the reflectivity to the assumed properties of cloud ice and snow particles. Finally, the CloudSat ice water content retrieval algorithm is applied to the profiles of 94-GHz reflectivity, producing 'simulated retrieved' values of ice water content, which can be compared to the `truth' values. The comparisons suggest that CloudSat ice water content retrievals are sensitive to the frozen particle properties often parameterized in models (e.g., particle density, particle size distributions). The sensitivity tests provide a better understanding of how the different components of the frozen water mass impact the ice water content retrieved by CloudSat. Such information is important when comparing the measurements to modeled frozen water mass quantities, including those from various levels of sophistication in global climate models. Additionally, we demonstrate how information gained in this study may be used for improving the retrieval system. A simple height-based retrieval correction that effectively corrects for the vertically varying characteristics of frozen particles is examined.

  2. Modelling soil-plant-atmosphere interactions by coupling the regional weather model WRF to mechanistic plant models

    Science.gov (United States)

    Klein, C.; Hoffmann, P.; Priesack, E.

    2012-04-01

    of evapotranspiration, heat flow and radiation of thermodynamic values. Bossel, H. 1996. "TREEDYN3 forest simulation model." Ecological modelling 90 (3): 187-227. CLC, 2006. CORINE Land Cover 2006. http://www.eea.europa.eu/themes/landuse/interactive/clc-download. Accessed 16.12.2012. Fei Chen, and Jimy Dudhia. 2010. Coupling an Advanced Land Surface-Hydrology Model with the Penn State-NCAR MM5 Modeling System. Part II: Preliminary Model Validation. Research-article. February 25. Skamarock, W. C. 2008. "Coauthors 2008: A description of the Advanced Research WRF version 3." NCAR Tech. Note NCAR/TN-475+ STR. http://www.wrf-model.org/. Thornley, John. 1998. Grassland dynamics: an ecosystem simulation model. Wallingford,New York: CAB international.

  3. A multimedia fate and chemical transport modeling system for pesticides: I. Model development and implementation

    Energy Technology Data Exchange (ETDEWEB)

    Li Rong; Yang Fuquan; Sloan, James J [Department of Earth and Environmental Sciences, University of Waterloo, Waterloo, ON N2L 3G1 (Canada); Scholtz, M Trevor, E-mail: sloanj@connect.uwaterloo.ca [ORTECH Environmental, 2395 Speakman Drive, Mississauga, ON L5K 1B3 (Canada)

    2011-07-15

    We have combined the US EPA MM5/MCIP/SMOKE/CMAQ modeling system with a dynamic soil model, the pesticide emission model (PEM), to create a multimedia chemical transport model capable of describing the important physical and chemical processes involving pesticides in the soil, in the atmosphere, and on the surface of vegetation. These processes include: agricultural practices (e.g. soil tilling and pesticide application mode); advection and diffusion of pesticides, moisture, and heat in the soil; partitioning of pesticides between soil organic carbon and interstitial water and air; emissions from the soil to the atmosphere; gas-particle partitioning and transport in the atmosphere; and atmospheric chemistry and dry and wet deposition of pesticides to terrestrial and water surfaces. The modeling system was tested by simulating toxaphene in a domain that covers most of North America for the period from 1 January 2000 to 31 December 2000. The results show obvious transport of the pesticide from the heavily contaminated soils in the southern United States and Mexico to water bodies including the Atlantic Ocean, the Gulf of Mexico and the Great Lakes, leading to significant dry and wet deposition into these ecosystems. The spatial distributions of dry and wet depositions differ because of their different physical mechanisms; the former follows the distribution of air concentrations whereas the latter is more biased to the North East due to the effect of precipitation.

  4. A multimedia fate and chemical transport modeling system for pesticides: I. Model development and implementation

    Science.gov (United States)

    Li, Rong; Scholtz, M. Trevor; Yang, Fuquan; Sloan, James J.

    2011-07-01

    We have combined the US EPA MM5/MCIP/SMOKE/CMAQ modeling system with a dynamic soil model, the pesticide emission model (PEM), to create a multimedia chemical transport model capable of describing the important physical and chemical processes involving pesticides in the soil, in the atmosphere, and on the surface of vegetation. These processes include: agricultural practices (e.g. soil tilling and pesticide application mode); advection and diffusion of pesticides, moisture, and heat in the soil; partitioning of pesticides between soil organic carbon and interstitial water and air; emissions from the soil to the atmosphere; gas-particle partitioning and transport in the atmosphere; and atmospheric chemistry and dry and wet deposition of pesticides to terrestrial and water surfaces. The modeling system was tested by simulating toxaphene in a domain that covers most of North America for the period from 1 January 2000 to 31 December 2000. The results show obvious transport of the pesticide from the heavily contaminated soils in the southern United States and Mexico to water bodies including the Atlantic Ocean, the Gulf of Mexico and the Great Lakes, leading to significant dry and wet deposition into these ecosystems. The spatial distributions of dry and wet depositions differ because of their different physical mechanisms; the former follows the distribution of air concentrations whereas the latter is more biased to the North East due to the effect of precipitation.

  5. On the practical applications of atmosphere-ocean and atmosphere-wave coupling in mesoscale numerical modeling

    Science.gov (United States)

    Kochanski, Adam

    The objectives of this work were to develop coupled atmosphere-ocean and atmosphere-wave models for the verification of the atmospheric simulations, model the small-scale ocean circulations, analyze the role of the atmospheric stability in the generation of coastal upwelling, improve the accuracy of numerical prediction over the coastal areas, and develop a parameterization of the swell-induced wind stress. The study confirmed the applicability of the high resolution Mesoscale Model 5 (MM5) wind field prediction to driving small scale ocean models applied to the U.S. West Coast, and showed that the small-scale circulation pattern of Bodega Bay can be well simulated even by the relatively simple 2D ocean model. Additional experiments performed with the complex 3D Princeton Ocean Model (POM) coupled with the MM5 showed the importance of the atmospheric stability in terms of the modification of the wind stress-curl pattern and the generation of coastal upwelling. The study revealed that the introduction of the stability effect to the wind stress computation may change the monthly mean wind stress curl by up to 0.15Pa/100km, and increase the simulated upwelling velocity by up to 25%, significantly improving the picture of the simulated upwelling and relaxation events. Further analysis performed with the MM5 model run at 9km resolution, showed that the introduction of the atmosphere-ocean coupling greatly improved the quality of the model results. The comparison with buoy data revealed that the atmosphere-ocean coupling led to a 95% increase in the correlation coefficients of the air temperature and heat fluxes, 23% for the wind direction, and up to 25% for the wind speed, and the reduction of the mean errors by up to 30%. The air-wave interaction model developed during this study showed the applicability of the innovative semi-analytical approach to the computation of the swell-induced stress. Its results also confirmed the importance of the swell-induced stress for

  6. Numerical Modeling of Regional Windblown Dust in the Pacific Northwest:Incorporation of an Improved Dust Emission Model

    Science.gov (United States)

    Sundram, I.; Claiborn, C.; Strand, T.; Lamb, B.; Chandler, D.; Saxton, K.

    2003-12-01

    Soil erosion by wind is a serious consequence of dryland agriculture in eastern Washington where the main adverse effects are loss of nutrient rich soil, reduced visibility during dust storms and regional air quality impacts in downwind populated areas. A multidisciplinary research effort to study windblown dust in central and eastern Washington was initiated under the Columbia Plateau PM 10 (CP 3) program. As part of this study, wind erosion and windblown dust emissions were measured in impacted population centers and a transport and dispersion model was developed for the region. The modeling system includes the use of a prognostic meteorological model, Mesoscale Metorological Model Version 5 (MM5), coupled with the CALMET/CALGRID Eularian modeling pair and a new dust emission module (EMIT-PM), developed specifically for this region from extensive soil sampling, portable wind tunnel measurements and intensive field campaigns. Surface wind observations were integrated into the diagnostic meteorological model, CALMET, along with wind fields generated by MM5 for six dust storm events that occurred in November 1990, October 1991, September 1993, November 1993, August 1996 and September 1999. Area dust emissions were generated using the CALMET wind fields along with detailed soil and land use maps in the EMIT-PM model and these hourly, gridded emissions were then used in CALGRID, which calculated hourly averaged concentrations of PM10 (particulate matter of aerodynamic diameter < 10 μ m) throughout the modeling domain. The predicted 24-hour average concentrations compared favorably to observed concentrations that were measured at selected locations within the modeling domain. For all the simulated events, with the exception of the August 1996 event, ratios of observed to predicted concentrations were within a range of 0.5 to 6.0. Because these ratios' were obtained without the need for a calibrated dust constant, it appears that the EMIT-PM provides an improved

  7. Application of high resolution land use and land cover data for atmospheric modeling in the Houston-Galveston metropolitan area, Part I: Meteorological simulation results

    Science.gov (United States)

    Cheng, Fang-Yi; Byun, Daewon W.

    To predict atmospheric conditions in an urban environment, the land surface processes must be accurately described through the use of detailed land use (LU) and land cover (LC) data. Use of the U.S. Geological Survey (USGS) 25-category data, currently in the Fifth-generation Mesoscale Model (MM5), with the Noah land surface model (LSM) and MRF (medium-range forecast) planetary boundary layer (PBL) schemes resulted in the over-prediction of daytime temperatures in the Houston downtown area due to the inaccurate representation as a completely impervious surface. This bias could be corrected with the addition of canopy water in the urban areas from the evapotranspiration effects of urban vegetation. A more fundamental approach would be to utilize an LULC dataset that represents land surface features accurately. The Texas Forest Service (TFS) LULC dataset established with the LANDSAT satellite imagery correctly represents the Houston-Galveston-Brazoria (HGB) area as mixtures of urban, residential, grass, and forest LULC types. This paper describes how the Noah LSM and PBL schemes in the MM5 were modified to accommodate the TFS-LULC data. Comparisons with various meteorological measurements show that the MM5 simulation made with the high resolution LULC data improves the boundary layer mixing conditions and local wind patterns in the Houston Ship Channel, which is a critically important anthropogenic emission area affecting the HGB air pollution problems. In particular, when the synoptic flows are weak, the improved LULC data simulates the asymmetrically elongated Houston heat island convergence zone influencing the location of the afternoon Gulf of Mexico sea-breeze front and the Galveston Bay breeze flows. This paper is part I of a two-part study and focuses on the meteorological simulation. In part II, effects of using the different meteorological inputs on air quality simulations are discussed.

  8. Regional source identification using Lagrangian stochastic particle dispersion and HYSPLIT backward-trajectory models.

    Science.gov (United States)

    Koracin, Darko; Vellore, Ramesh; Lowenthal, Douglas H; Watson, John G; Koracin, Julide; McCord, Travis; DuBois, David W; Chen, L W Antony; Kumar, Naresh; Knipping, Eladio M; Wheeler, Neil J M; Craig, Kenneth; Reid, Stephen

    2011-06-01

    The main objective of this study was to investigate the capabilities of the receptor-oriented inverse mode Lagrangian Stochastic Particle Dispersion Model (LSPDM) with the 12-km resolution Mesoscale Model 5 (MM5) wind field input for the assessment of source identification from seven regions impacting two receptors located in the eastern United States. The LSPDM analysis was compared with a standard version of the Hybrid Single-Particle Lagrangian Integrated Trajectory (HYSPLIT) single-particle backward-trajectory analysis using inputs from MM5 and the Eta Data Assimilation System (EDAS) with horizontal grid resolutions of 12 and 80 km, respectively. The analysis included four 7-day summertime events in 2002; residence times in the modeling domain were computed from the inverse LSPDM runs and HYPSLIT-simulated backward trajectories started from receptor-source heights of 100, 500, 1000, 1500, and 3000 m. Statistics were derived using normalized values of LSPDM- and HYSPLIT-predicted residence times versus Community Multiscale Air Quality model-predicted sulfate concentrations used as baseline information. From 40 cases considered, the LSPDM identified first- and second-ranked emission region influences in 37 cases, whereas HYSPLIT-MM5 (HYSPLIT-EDAS) identified the sources in 21 (16) cases. The LSPDM produced a higher overall correlation coefficient (0.89) compared with HYSPLIT (0.55-0.62). The improvement of using the LSPDM is also seen in the overall normalized root mean square error values of 0.17 for LSPDM compared with 0.30-0.32 for HYSPLIT. The HYSPLIT backward trajectories generally tend to underestimate near-receptor sources because of a lack of stochastic dispersion of the backward trajectories and to overestimate distant sources because of a lack of treatment of dispersion. Additionally, the HYSPLIT backward trajectories showed a lack of consistency in the results obtained from different single vertical levels for starting the backward trajectories. To

  9. Wind modeling of Chihuahuan Desert dust outbreaks

    Science.gov (United States)

    Rivera Rivera, Nancy I.; Gill, Thomas E.; Gebhart, Kristi A.; Hand, Jennifer L.; Bleiweiss, Max P.; Fitzgerald, Rosa M.

    The Chihuahuan Desert region of North America is a significant source of mineral aerosols in the Western Hemisphere, and Chihuahuan Desert dust storms frequently impact the Paso del Norte (El Paso, USA/Ciudad Juarez, Mexico) metropolitan area. A statistical analysis of HYSPLIT back trajectory residence times evaluated airflow into El Paso on all days and on days with synoptic (non-convective) dust events in 2001-2005. The incremental probability—a measure of the areas most likely to have been traversed by air masses arriving at El Paso during dusty days—was only strongly positively associated with the region west-southwest of the city, a zone of known dust source areas. Focused case studies were made of major dust events on 15 April and 15 December 2003. Trajectories approached the surface and MM5 (NCAR/Penn State Mesoscale Model) wind speeds increased at locations consistent with dust sources observed in satellite imagery on those dates. Back trajectory and model analyses suggested that surface cyclones adjacent to the Chihuahuan Desert were associated with the extreme dust events, consistent with previous studies of dust storms in the Southern High Plains to the northeast. The recognition of these meteorological patterns serves as a forecast aid for prediction of dust events likely to impact the Paso del Norte.

  10. Numerical modeling of windblown dust in the Pacific Northwest with improved meteorology and dust emission models

    Science.gov (United States)

    Sundram, Irra; Claiborn, Candis; Strand, Tara; Lamb, Brian; Chandler, Dave; Saxton, Keith

    2004-12-01

    Soil erosion by wind is a serious consequence of dry land agriculture in eastern Washington, where the main adverse effects are loss of nutrient-rich soil, reduced visibility during dust storms and degradation of air quality. A multidisciplinary research effort to study windblown dust in central and eastern Washington was initiated under the Columbia Plateau PM10 (CP3) program, which involved measuring wind erosion and windblown dust emissions at sites throughout the region and developing a transport and dispersion model for the area. The modeling system includes the prognostic meteorological model, Mesoscale Metorological Model Version 5 (MM5), coupled with the CALMET/CALGRID Eularian modeling pair and a new dust emission module (EMIT-PM). Improvements to the modeling system included employing higher spatial resolutions for the meteorological models and improved parameterizations of emission factors in EMIT-PM. Meteorological fields, dust emissions and the resulting dust concentrations were simulated for six historical regional dust storms: 23 November 1990, 21 October 1991, 11 September 1993, 3 November 1993, 30 August 1996 and 23-25 September 1999. For all the simulated events, with the exception of the August 1996 event, ratios of observed to predicted concentrations were favorable, within a range of 0.5-6.0 without calibration of the dust emission model; PM10 emissions averaged 22 Gg per 24-hour event, representing approximately 1% of the daily dust flux on a global basis. These results showed that the model performed best for large, strong dust storms but did not simulate smaller storms as well.

  11. Aerosol Simulation in the Mexico City Metropolitan Area during MCMA2003 using CMAQ/Models3

    Science.gov (United States)

    Bei, N.; Zavala, M.; Lei, W.; de Foy, B.; Molina, L.

    2007-12-01

    CMAQ/Models3 has been employed to simulate the aerosol distribution and variation during the period from 13 to 16 April 2003 over the Mexico City Metropolitan Area as part of MCMA-2003 campaign. The meteorological fields are simulated using MM5, with three one-way nested grids with horizontal resolutions of 36, 12 and 3 km and 23 sigma levels in the vertical. MM5 3DVAR system has also been incorporated into the meteorological simulations. Chemical initial and boundary conditions are interpolated from the MOZART output. The SAPRC emission inventory is developed based on the official emission inventory for MCMA in 2004. The simulated mass concentrations of different aerosol compositions, such as elemental carbon (EC), primary organic aerosol (POA), secondary organic aerosol (SOA), nitrate, ammonium, and sulfate have been compared to the measurements taken at the National Center for Environmental Research and Training (Centro Nacional de Investigacion y Capacitacion Ambiental, CENICA) super-site. Hydrocarbon-like organic aerosol (HOA) and oxygenated organic aerosol (OOA) are used as observations of POA and SOA, respectively in this study. The preliminary model results show that the temporal evolutions of EC and POA are reasonable compared with measurements. The peak time of EC and POA are basically reproduced, thus validating the emission inventory and its processing through CMAQ/Models3. But the magnitude of EC and POA are underestimated over the entire episode. The modeled nitrate and ammonium concentrations are overestimated on most of the days. There is 1-2 hour difference between the simulated peak time of nitrate and ammonium aerosols compared to observations at CENICA. The simulated mass concentrations of SOA and sulfate are significantly underestimated. The reasons of the discrepancy between simulations and measurements are due to the uncertainties existing in the emission inventory, meteorological fields, and as well as aerosol formation mechanism in the case

  12. An air quality modeling study comparing two possible sites for the new international airport for Mexico City.

    Science.gov (United States)

    Jazcilevich, Aron D; García, Agustín R; Ruiz-Suárez, L Gerardo; Cruz-Nuñez, Xóchitl; Delgado, Javier C; Tellez, Carlos; Chias, Luis B

    2003-03-01

    Using an air quality model, two future urban scenarios induced by the construction of the new international airport for Mexico City are compared at a regional level. The air quality model couples the meteorology model MM5 and state-of-the-art photochemistry. The air quality comparison is made using metrics for the criterion gases selected for the study. From the two urban scenarios compared, the option for Tizayuca is moderately better than the option for Texcoco, because relative reductions in O3 and other photochemical pollutants are achieved over highly populated areas. Regardless of the site, the air quality for the central region of Mexico in the future will deteriorate. In the region of central Mexico, SO2 and NO2 will become important pollutants.

  13. Impacts of inhomogeneous landscapes in oasis interior on the oasis self-maintaining mechanism by integrating numerical model with satellite data

    Directory of Open Access Journals (Sweden)

    X. Meng

    2012-02-01

    Full Text Available Mesoscale meteorological modeling is an important tool to help understand the energy budget of the oasis. While basic dynamic and thermodynamic processes for oasis self-maintaining in the desert environment is well investigated, influence of heterogeneous landscapes of oasis interior on the processes are still important and remain to be investigated. In this study, two simulations are designed for investigating the influence of inhomogeneity. In the first case, land surface parameters including land-use types, vegetation cover fraction, and surface layer soil moisture are derived by satellite remote sensing data from EOS/MODIS, and then be used specify the respective options in the MM5 model, to describe a real inhomogeneity for the oasis interior. In the other run, land use types are set to MM5 default, in which landscapes in the oasis interior is relative uniform, and then surface layer soil moisture and vegetation fraction is set to be averages of the first case for the respective oasis and desert surface lying, to represent a relative homogeneity. Results show that the inhomogeneity leads to a weaker oasis "cold-wet island" effect and a stronger turbulence over the oasis interior, both of which will reduce the oasis-desert secondary circulation and increase the evaporation over the oasis, resulting in a negative impact on the oasis self-protecting mechanism. The simulation of homogeneity indicates that the oasis may be more stable even with relative lower soil moisture if landscapes in the oasis interior are comparatively uniform.

  14. Fog forecasting: ``old fashioned'' semi-empirical methods from radio sounding observations versus ``modern'' numerical models

    Science.gov (United States)

    Holtslag, M. C.; Steeneveld, G. J.; Holtslag, A. A. M.

    2010-07-01

    Fog forecasting is a very challenging task due to the local and small-scale nature of the relevant physical processes and land surface heterogeneities. Despite the many research efforts, numerical models remain to have difficulties with fog forecasting, and forecast skill from direct model output is relatively poor. In order to put the progress of fog forecasting in the last decades into a historical perspective, we compare the fog forecasting skill of a semi-empirical method based on radio sounding observations (developed in the 60s and 70s) with the forecasting skill of a state-of-the-art numerical weather prediction model (MM5) for The Netherlands. The semi-empirical method under investigation, the Fog Stability Index, depends solely on the temperature difference between the surface and 850 hPa, the surface dew point depression and the wind speed at 850 hPa, and a threshold value to indicate the probability of fog in the coming hours. Using the critical success index (CSI) as a criterion for forecast quality, we find that the Fog Stability Index is a rather successful predictor for fog, with similar performance as MM5. The FSI could even been optimized for different observational stations in the Netherlands. Also, it appears that adding the 10 m wind as a predictor did not increase the CSI score for all stations. The results of the current study clearly indicate that the current state of knowledge requires improvement of the physical insight in different physical processes in order to beat simple semi-empirical methods.

  15. Evaluation of the capability of RegCM4.0 in simulating East African climate

    Science.gov (United States)

    Ogwang, Bob Alex; Chen, Haishan; Li, Xing; Gao, Chujie

    2016-04-01

    The International Centre for Theoretical Physics (ICTP) regional climate model RegCM4.0 is used in this study to examine its ability to reproduce the climate of East Africa (EA) in regard to the annual cycle and June-to-August (JJA) seasonal climatology. Two domain sizes [large domain (LD) and small domain (SD)] and two cumulus convection schemes [Grell convection scheme with Fritsch-Chappell closure assumption (GRE scheme) and MIT scheme (EMA scheme)] are used. Simulations were done for the period 1989-2008 at a resolution of 50 km. The experiments were performed with the initial and lateral boundary conditions obtained from ERA-Interim-gridded reanalysis data at a 1.5° resolution. The variables investigated are precipitation, temperature, humidity, diurnal temperature range, and 850-hPa winds. Results show that the model realistically reproduces the East African climate, with a few discrepancies due to the different cumulus convection schemes and the domain sizes used. Grell with Fritsch-Chappell (Grell-FC) scheme captures well the observed climate in regard to the annual cycle and June-to-August seasonal climatology, with a tendency to underestimate rainfall over the JJA rainfall maximum region (RMR). This scheme performs better in LD than in SD. EMA scheme similarly captures well the observed climatology. It tends to overestimate rainfall over RMR. It however performs better in SD than in LD. The ensemble mean of simulations with GRE and EMA schemes (ENSM) tends to offer an improved representation of the observed climate, with a few discrepancies owing to the individual schemes used. In general, therefore, considering the performance of the model in both domains, the East African climate based on this study is better simulated by the Grell-FC scheme over LD. The observed biases in this study signify that the ability of the model in simulating climate over East Africa is still a significant challenge. Thus, future work must focus on improving the performance of

  16. Mesoscale numerical modeling of meteorological events in a strong topographic gradient in the northeastern part of Mexico

    Energy Technology Data Exchange (ETDEWEB)

    Pineda-Martinez, Luis F.; Carbajal, Noel [IPICYT, San Luis Potosi (Mexico)

    2009-08-15

    A series of numerical experiments were carried out to study the effect of meteorological events such as warm and cold air masses on climatic features and variability of a understudied region with strong topographic gradients in the northeastern part of Mexico. We applied the mesoscale model MM5. We investigated the influence of soil moisture availability in the performance of the model under two representative events for winter and summer. The results showed that a better resolution in land use cover improved the agreement among observed and calculated data. The topography induces atmospheric circulation patterns that determine the spatial distribution of climate and seasonal behavior. The numerical experiments reveal regions favorable to forced convection on the eastern side of the mountain chains Eastern Sierra Madre and Sierra de Alvarez. These processes affect the vertical and horizontal structure of the meteorological variables along the topographic gradient. (orig.)

  17. A Numerical Study of Sensitivity of the Physical Dissipative Technique to Precipitation Parameterization in a Mesoscale Model

    Institute of Scientific and Technical Information of China (English)

    LIU Ying; LIU Chongjian; XU Hui; ZHAO Yongming

    2005-01-01

    In this paper the numerical comparative experiments on sensitivity of the physical dissipative technique to the precipitation parameterizations, especially the different combination of the explicit micro-physical schemes and cumulus convection parameterizations, in the PSU/NCAR mesoscale model MM5V3 with a triple-nested domain are conducted using the case of heavy rain occurring in the northern China in October 2003. The experiments have revealed some meaningful results, notably the dramatic improvement in the simulative accuracy and quality by the physical dissipative technique based on the second law of thermodynamics, meanwhile, the weak sensitivity of the technique to the schemes of parameterization resulting mainly from improving the field of rainfall by the physical dissipative technique has been reached via improving the outputs of the model variables such as wind field determining the divergence field that is one of the most important factors in the case of designing the schemes of precipitation parameterization.

  18. Testing the Ability of Numerical Model to Simulate Climate and Its Change With 4D-EOF Analysis

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    The four-dimensional empirical orthogonal function (4D-EOF), which in reality is a simple combination of three-dimensional EOF (3D-EOF) and extended EOF (EEOF), is put forward in this paper to test the ability of numerical model to simulate climate and its change. The 4D-EOF analysis is able to reveal not only the horizontal characteristic pattern of analyzed variable, and its corresponding annual and inter-annual variations, but also the vertical structural characteristics. The method suggested is then used to analyze the monthly mean 100-, 500-, 700-, and 1000-hPa geopotential height fields (4941 grids and grid spacing 60 km) and their anomaly fields in 1989-1998 simulated by the MM5V3 from the RMIP (Regional Climate Model Inter-comparison Project for East Asia)-Ⅱ, as well as their counterparts (used as the observed fields)from the NCEP/NCAR re-analysis dataset in the same period. The ability of MM5V3 in simulating East Asian climate and its change is tested by comparing the 4D-EOF analysis results of the simulated and observed datasets. The comparative analyzed results show that the horizontal pattern of the first eigenvector of the observed monthly mean geopotential height fields and its vertical equivalent barotropic feature were well simulated; the simulations of the first two eigenvectors of the observed monthly mean geopotential height anomaly fields were also successful for their horizontal abnormal distributions and significant equivalent barotropic features in the vertical were well reproduced; and furthermore, the observed characteristics,such as the variation with height, the annual and inter-annual variations of the monthly mean geopotential height/anomaly fields were also well reflected in the simulation. Therefore, the 4D-EOF is able to comprehensively test numerical model's ability of simulating the climate and its change, and the simulation ability of MM5V3 for the climate and its change in East Asia in the 1990s was satisfactory.

  19. Estimation of tritium dispersion from the spent nuclear fuel reprocessing plant in Rokkasho using an atmospheric dispersion model

    Energy Technology Data Exchange (ETDEWEB)

    Abe, Koichi; Kakiuchi, Hideki; Iyogi, Takashi; Hisamatsu, Shun' ichi [Institute for Environmental Sciences, Rokkasho, Aomori 039-3212 (Japan); Akata, Naofumi [Institute for Environmental Sciences, Rokkasho, Aomori 039-3212 (Japan); National Institute for Fusion Science, Toki, Gifu 509-5292 (Japan); Chiang, Jing-Hsien; Suwa, Hiroji [Japan NUS Co., Ltd., Tokyo 160-0023 (Japan)

    2014-07-01

    Japan's first large-scale commercial plant for reprocessing spent nuclear fuel was constructed in Rokkasho, Japan, by Japan Nuclear Fuel Limited (JNFL). Final tests of plant operation carried out with spent fuels since 31 March 2006 have indicated that small amounts of radionuclides (mainly {sup 3}H, {sup 14}C, {sup 85}Kr, and {sup 129}I) are discharged into the atmosphere from the main stack of the plant. To estimate the atmospheric dispersion of {sup 3}H discharged from the plant, we used a combination of the Fifth-Generation Penn State/NCAR Mesoscale Model (MM5) and the CG-MATHEW/ADPIC models, Version 5.0 (ARAC-2). Simulation results were validated with atmospheric {sup 3}H concentrations and wet deposition rates measured at the Institute for Environmental Sciences (IES), located 2.6 km east from the stack. Biweekly atmospheric HTO, HT, and CH3T samples and monthly precipitation samples were collected at IES from April 2006 to February 2009 (the test period). Concentrations of {sup 3}H in the samples were measured with a low-background liquid scintillation counter (LSC-LB5, Hitachi Aloka Medical, Ltd., Tokyo, Japan). To simulate the dispersion of {sup 3}H from the stack, a meteorological field was calculated by MM5 and used as input to ARAC-2, which consists of a mass-consistent wind model and a particle-tracing-type dispersion model. The simulation areas were 315 km x 315 km for MM5 and 50 km x 50 km for ARAC-2. The following meteorological data were input to MM5: grid point data derived from the Mesoscale Model of the Japan Meteorological Agency (JMA), data from JMA's Automated Meteorological Data Acquisition System (AMeDAS), and wind speed and direction at IES and JNFL measured every 10 min. The weekly discharge rates of {sup 3}H disclosed by JNFL were used as the source term for ARAC-2. The concentrations of {sup 3}H in atmospheric moisture and precipitation samples increased from their background values during the test period. As an index of

  20. Tree-ring proxy based temperature reconstructions and climate model simulations: cross-comparison at the Pyrenees

    Directory of Open Access Journals (Sweden)

    I. Dorado Liñán

    2011-11-01

    Full Text Available May-to-September mean temperatures over the larger Pyrenees area (Northern Spain and Southern France are reconstructed for the last Millennium from 22 maximum density (MXD tree-ring chronologies. For the standardization of the tree-ring series, two detrending methods (Regional Curve Standardization (RCS and 300-yr spline were combined with and without an adaptive power transform (PT for variance stabilization in the individual series. Thus, four different standardization procedures were applied to the data. Additionally, different regional chronologies were generated by computing a mean composite, averaging the local chronologies, or by applying Principal Components Analysis (PCA to extract common variance from the subsets of individual MXD chronologies.

    Calibration-verification trials were performed using the product of the three regional aggregation methods in split periods: 1900–1952 and 1953–2006. Two methods were used to calibrate the regional chronology: regression and a simple variance-matching, sometimes also known as composite-plus-scaling. The resulting set of temperature reconstructions was compared with climate simulations performed with global (ECHO-G over the last Millennium for the target region and regional (MM5 climate models.

    The reconstructions reveal inter-annual to multi-centennial temperature variations at the Pyrenees region for the last 750 yr. Generally, variations at inter-decadal timescales, including the cold periods associated with the solar minima, are common to all reconstruction variants although some discrepancies are found at longer timescales.

    The simulations of the global circulation model ECHO-G and the regional model MM5 agree with the tree-ring based reconstructions at decadal to multi-decadal time-scales. However, the comparison also highlights differences that need to be understood, such as the amplitude of the temperature variations and the discrepancies regarding the 20th

  1. Meteorological Modeling of a Houston Ozone Episode

    Science.gov (United States)

    Nielsen-Gammon, J. W.

    2002-12-01

    The State of Texas requires accurate meteorological simulations of a Houston-Galveston ozone episode to drive their photochemical model for regulatory purposes. The episode of greatest interest occurred during TexAQS-2000, so there is an unusually large amount of data available for driving and validating the simulation. The key meteorological process to simulate is the sea breeze. In the Houston area, this sea breeze takes two forms, both of which typically occur on a summertime day. The first form is the sea breeze front, which forms along the coast of the Gulf of Mexico and Galveston Bay if the midday winds are light or offshore and travels inland during the afternoon and early evening. The second form is an inertia-gravity wave response of unusually large amplitude and horizontal scale, due to Houston's proximity to 30 N. It manifests itself as a steady rotation of the wind, superimposed on the background flow, with an amplitude of 2-3 m/s. The MM5 (v3.4) model characteristics were tailored to simulate this phenomenon. Over 20 vertical levels were located in the lowest 300 mb. The soil moisture availability was adjusted according to rainfall prior to and during the event so that the model simulated a reasonably accurate land-sea and urban-rural temperature contrast. A planetary boundary layer scheme was chosen to produce lower atmospheric structures similar to those observed in special soundings. To further increase the agreement between the model and observed fields, data from five profilers and one Doppler lidar were assimilated into the simulation. Assimilation parameters were chosen to provide a large impact on the large-scale, slowly-varying winds while allowing the smaller-scale sea breeze front and other such phenomena to evolve according to the internal dynamics of the model. The assimilation was essential for compelling the model to capture a nighttime low-level jet that was present during part of the episode and which the unassimilated model runs were

  2. Modelling the photochemical pollution over the metropolitan area of Porto Alegre, Brazil

    Science.gov (United States)

    Borrego, C.; Monteiro, A.; Ferreira, J.; Moraes, M. R.; Carvalho, A.; Ribeiro, I.; Miranda, A. I.; Moreira, D. M.

    2010-01-01

    The main purpose of this study is to evaluate the photochemical pollution over the Metropolitan Area of Porto Alegre (MAPA), Brazil, where high concentrations of ozone have been registered during the past years. Due to the restricted spatial coverage of the monitoring air quality network, a numerical modelling technique was selected and applied to this assessment exercise. Two different chemistry-transport models - CAMx and CALGRID - were applied for a summer period, driven by the MM5 meteorological model. The meteorological model performance was evaluated comparing its results to available monitoring data measured at the Porto Alegre airport. Validation results point out a good model performance. It was not possible to evaluate the chemistry models performance due to the lack of adequate monitoring data. Nevertheless, the model intercomparison between CAMx and CALGRID shows a similar behaviour in what concerns the simulation of nitrogen dioxide, but some discrepancies concerning ozone. Regarding the fulfilment of the Brazilian air quality targets, the simulated ozone concentrations surpass the legislated value in specific periods, mainly outside the urban area of Porto Alegre. The ozone formation is influenced by the emission of pollutants that act as precursors (like the nitrogen oxides emitted at Porto Alegre urban area and coming from a large refinery complex) and by the meteorological conditions.

  3. A hydrometeorological model intercomparison as a tool to quantify the forecast uncertainty in a medium size basin

    Directory of Open Access Journals (Sweden)

    A. Amengual

    2008-08-01

    Full Text Available In the framework of AMPHORE, an INTERREG III B EU project devoted to the hydrometeorological modeling study of heavy precipitation episodes resulting in flood events and the improvement of the operational hydrometeorological forecasts for the prediction and prevention of flood risks in the Western Mediterranean area, a hydrometeorological model intercomparison has been carried out, in order to estimate the uncertainties associated with the discharge predictions. The analysis is performed for an intense precipitation event selected as a case study within the project, which affected northern Italy and caused a flood event in the upper Reno river basin, a medium size catchment in the Emilia-Romagna Region.

    Two different hydrological models have been implemented over the basin: HEC-HMS and TOPKAPI which are driven in two ways. Firstly, stream-flow simulations obtained by using precipitation observations as input data are evaluated, in order to be aware of the performance of the two hydrological models. Secondly, the rainfall-runoff models have been forced with rainfall forecast fields provided by mesoscale atmospheric model simulations in order to evaluate the reliability of the discharge forecasts resulting by the one-way coupling. The quantitative precipitation forecasts (QPFs are provided by the numerical mesoscale models COSMO and MM5.

    Furthermore, different configurations of COSMO and MM5 have been adopted, trying to improve the description of the phenomena determining the precipitation amounts. In particular, the impacts of using different initial and boundary conditions, different mesoscale models and of increasing the horizontal model resolutions are investigated. The accuracy of QPFs is assessed in a threefold procedure. First, these are checked against the observed spatial rainfall accumulations over northern Italy. Second, the spatial and temporal simulated distributions are also examined over the catchment of interest

  4. Evaluation of a regional model climatology in Europe using dynamical downscaling from a seamless Earth prediction approach (EC-Earth)

    Science.gov (United States)

    Jimenez-Guerrero, Pedro; Montavez, Juan P.; Baldasano, Jose M.

    2010-05-01

    Climate and weather forecasting applications share a common ancestry and build on the same physical principles. Nevertheless, climate research and numerical weather prediction are commonly seen as different disciplines. The emerging concept of "seamless prediction" forges weather forecasting and climate change studies into a single framework (Palmer et al., 2008). In principle, as models develop towards higher resolution and more feedbacks are included, some aspects of model uncertainty should reduce. However, global models can only resolve processes down to 50-100 km at present. Moreover, users of climate information often require much higher detail and downscaling methods are needed to provide regional climate information consistent with global climate trajectories. Therefore, this work presents an evaluation of the ability of a regional climate model (RCM) to reproduce the present climatology over Europe using a high resolution (25 km). The RCM used in this study is a climate version of the MM5 model (Fernández et al., 2007). The analysis here focuses on the annual and seasonal biases and variability for temperature (mean, maximum and minimum) and precipitation. The statistical parameters are obtained by interpolating the simulated values on the E-OBS gridded dataset from the European Climate Assessment & Dataset (ECA&D) at a resolution of 0.5° for the period 1990-2000. The novel approach of this contribution is that the driving model is EC-Earth version 2 (Hazeleger et al., 2010), which follows the seamless prediction approach to provide climate forcings to the regional model. The atmospheric model of EC-Earth is based on ECMWF's Integrated Forecast System, cycle 31r1, corresponding to the current seasonal forecast system of ECMWF. The standard configuration runs at T159 horizontal spectral resolution with 62 vertical levels. The ocean component is based on version 2 of the NEMO model with a horizontal resolution of nominally 1 degree and 42 vertical levels

  5. Leadership Models.

    Science.gov (United States)

    Freeman, Thomas J.

    This paper discusses six different models of organizational structure and leadership, including the scalar chain or pyramid model, the continuum model, the grid model, the linking pin model, the contingency model, and the circle or democratic model. Each model is examined in a separate section that describes the model and its development, lists…

  6. Advanced air quality modeling system for the simulation of photochemical ozone formation over North Carolina

    Energy Technology Data Exchange (ETDEWEB)

    Jang, C.; Wheeler, N.; Dolwick, P.; Olerud, D.; Houyoux, M. [MCNC-North Carolina Supercomputing Center, Research Triangle Park, NC (United States); Timin, B.; Lawrimore, J.; Holman, S. [North Carolina Dept. of Environment and Natural Resources, Raleigh, NC (United States). Div. of Air Quality; Jeffries, H. [Univ. of North Carolina, Chapel Hill, NC (United States). Dept. of Environmental Sciences and Engineering

    1998-12-31

    An advanced air quality modeling system is used to simulate the formation of photochemical oxidants, mainly ozone, over North Carolina. The objective of this modeling study is to successfully model the formation processes of ozone in North Carolina to lead to effective ozone control strategy developments for both 1-hour and 8-hour standards and eventually to address the particulate matter issue. The modeling system selected for this ongoing project is the North Carolina Supercomputing Center`s Environmental Decision Support System (EDSS), which evolved from a working prototype of EPA`s Third Generation Modeling System, or Models-3. The EDSS consists of three major modeling components : the Multiscale Air Quality SImulation Platform (MAQSIP) for chemistry/transport modeling, Mesoscale Model Version 5 (MM5) for meteorological modeling, and Sparse Matrix Operator Kernel Emissions (SMOKE) system for emission modeling. Two inner subdomains at 12-km and 4-km grid resolutions centered over Charlotte are nested inside a coarse domain at a 36-km resolution. Sixteen vertical layers with a denser grid at lower altitude are used to better resolve the mixing layer. The CB-IV chemistry mechanism with updated isoprene chemistry and radical-radical reactions is used to simulate the chemical transformations of reacting species. Preliminary results show that the MAQSIP has reasonably simulated the temporal and spatial distribution of ozone as compared to observations in the first 6-day episode during July 10--15, 1995. Improved ozone predictions are shown in the model using finer grid resolution. Various ozone sensitivity studies on the model inputs such as initial and boundary conditions and the existence of clouds are under testing. An innovative analysis tool for model evaluation and error detection, the Process Analysis method, is also applied to help understand the regulating processes that lead to formation of ozone.

  7. Evaluation of the Operational Multi-scale Environment model with Grid Adaptivity (OMEGA) for use in Wind Energy Applications in the Great Basin of Nevada

    Science.gov (United States)

    King, Kristien C.

    In order to further assess the wind energy potential for Nevada, the accuracy of a computational meteorological model, the Operational Multi-scale Environment model with Grid Adaptivity (OMEGA), was evaluated by comparing simulation results with data collected from a wind monitoring tower near Tonopah, NV. The state of Nevada is characterized by high mountains and low-lying valleys, therefore, in order to determine the wind potential for the state, meteorological models that predict the wind must be able to accurately represent and account for terrain features and simulate topographic forcing with accuracy. Topographic forcing has a dominant role in the development and modification of mesoscale flows in regions of complex terrain, like Tonopah, especially at the level of wind turbine blade heights (~80 m). Additionally, model factors such as horizontal resolution, terrain database resolution, model physics, time of model initialization, stability regime, and source of initial conditions may each affect the ability of a mesoscale model to forecast winds correctly. The observational tower used for comparison was located at Stone Cabin, Nevada. The tower had both sonic anemometers and cup anemometers installed at heights of 40 m, 60 m, and 80 m above the surface. During a previous experiment, tower data were collected for the period February 9 through March 10, 2007 and compared to model simulations using the MM5 and WRF models at a number of varying horizontal resolutions. In this previous research, neither the MM5 nor the WRF showed a significant improvement in ability to forecast wind speed with increasing horizontal grid resolution. The present research evaluated the ability of OMEGA to reproduce point winds as compared to the observational data from the Stone Cabin Tower at heights of 40 m, 60 m, and 80 m. Unlike other mesoscale atmospheric models, OMEGA incorporates an unstructured triangular adaptive grid which allows for increased flexibility and accuracy in

  8. Model Transformations? Transformation Models!

    NARCIS (Netherlands)

    Bézivin, J.; Büttner, F.; Gogolla, M.; Jouault, F.; Kurtev, I.; Lindow, A.

    2006-01-01

    Much of the current work on model transformations seems essentially operational and executable in nature. Executable descriptions are necessary from the point of view of implementation. But from a conceptual point of view, transformations can also be viewed as descriptive models by stating only the

  9. Modelling business models

    NARCIS (Netherlands)

    Simonse, W.L.

    2014-01-01

    Business model design does not always produce a “design” or “model” as the expected result. However, when designers are involved, a visual model or artifact is produced. To assist strategic managers in thinking about how they can act, the designers’ challenge is to combine both strategy and design n

  10. Mesoscale modeling of the production and the three-dimensional transport of nitrogen oxides in thunderstorms; Mesoskalige Modellierung der Produktion und des dreidimensionalen Transports von Stickoxiden durch Gewitter

    Energy Technology Data Exchange (ETDEWEB)

    Fehr, T.

    2000-07-01

    Nitrogen oxides, NO{sub x} = NO + NO{sub 2}, play a fundamental role in tropospheric chemistry. Compared to other sources, the contribution of lightning induced NO{sub x} (LNO{sub x}) is known with considerable uncertainties and difficult to determine experimentally. The distribution of nitrogen oxides in an isolated thunderstorm is investigated using a modified version of the Penn State/NCAR Mesoscale Model (MM5) with cloud-scale resolution. A Lagrangian particle model has been developed to represent the NO{sub x} released by individual flashes. The position of the flash, the flash type, the geometrical properties of the channel, and the amount of emitted NO{sub x} are introduced to the MM5 in a parameterized form. On July 21, 1998, during the European lightning nitrogen oxides project (EULINOX) field campaign, a supercell development was observed in the German alpine foreland. Anvil penetrations by the DLR Falcon aircraft contributed high resolution profiles of NO{sub x}. DLR radar observation covered the complete life cycle of the thunderstorm. The lightning activity was recorded with a lightning positioning and tracking system (LPATS) run by local power suppliers, while radiosonde and aircraft measurements supplied detailed information on the atmospheric stratification ahead of the thunderstorm. This meteorological information was used to initalize a cloud-scale MM5 simulation. The modeled thunderstorm reproduces many observed properties, e.g. cell splitting, propagation speed and direction, anvil and overshooting top height, and WER (weak echo region). The number of simulated cloud-to-ground flashes, as well as the temporal evolution of the lightning activity are comparable to the LPAT observations. The general transport properties of the model thunderstorm are investigated using an inert PBL-tracer, as well as trajectory analysis. The simulated lightning activity leads to the release of approximately 1 000 000 NO{sub x}-particles. The thunderstorm produces 28

  11. Regional/Urban Air Quality Modeling Assessment over China Using the Models-3/CMAQ System

    Science.gov (United States)

    Fu, J. S.; Jang, C. C.; Streets, D. G.; Li, Z.; Wang, L.; Zhang, Q.; Woo, J.; Wang, B.

    2004-12-01

    China is the world's most populous country with a fast growing economy that surges in energy comsumption. It has become the second largest energy consumer after the United States although the per capita level is much lower than those found in developed or developing countries. Air pollution has become one of the most important problems of megacities such as Beijing and Shanghai and has serious impacts on public health, causes urban and regional haze. The Models-3/CMAQ modeling application that has been conducted to simulate multi-pollutants in China is presented. The modeling domains cover East Asia (36-kmx36-km) including Japan, South Korea, Korea DPR, Indonesia, Thailand, India and Mongolia, East China (12-kmx12-km) and Beijing/Tianjing, Shanghai (4-kmx4-km). For this study, the Asian emission inventory based on the emission estimates of the year 2000 that supported the NASA TRACE-P program is used. However, the TRACE-P emission inventory was developed for a different purpose such as global modeling. TRACE-P emission inventory may not be practical in urban area. There is no China national emission inventory available. Therefore, TRACE-P emission inventory is used on the East Asia and East China domains. The 8 districts of Beijing and Shanghai local emissions inventory are used to replace TRACE-P in 4-km domains. The meteorological data for the Models-3/CMAQ run are extracted from MM5. The model simulation is performed during the period January 1-20 and July 1-20, 2001 that presented the winter and summer time for China areas. The preliminary model results are shown O3 concentrations are in the range of 80 -120 ppb in the urban area. Lower urban O3 concentrations are shown in Beijing areas, possibly due to underestimation of urban man-made VOC emissions in the TRACE-P inventory and local inventory. High PM2.5 (70ug/m3 in summer and 150ug/m3 in winter) were simulated over metropolitan & downwind areas with significant secondary constituents. More comprehensive

  12. China summer precipitation simulations using an optimal ensemble of cumulus schemes

    Institute of Scientific and Technical Information of China (English)

    Shuyan LIU; Wei GAO; Min XU; Xueyuan WANG; Xin-Zhong LIANG

    2009-01-01

    RegCM3 (REGional Climate Model) simulations of precipitation in China in 1991 and 1998 are very sensitive to the cumulus parameterization. Among the four schemes available, none has superior skills over the whole of China, but each captures certain observed signals in distinct regions. The Grell scheme with the FritschChappell closure produces the smallest biases over the North; the Grell scheme with the Arakawa-Schubert closure performs the best over the southeast of 100°E;the Anthes-Kuo scheme is superior over the northeast; and the Emanuel scheme is more realistic over the southwest of 100~E and along the Yangtze River Basin. These differences indicate a strong degree of independence and complementarity between the parameterizations. As such,an ensemble is developed from the four schemes, whose relative contributions or weights are optimized locally to yield overall minimum root-mean-square errors from observed daily precipitation. The skill gain is evaluated by applying the identical distribution of the weights in a different period. It is shown that the ensemble always produces gross biases that are smaller than the individual schemes in both 1991 and 1998. The ensemble, however,cannot eliminate the large rainfall deficits over the southwest of 100°E and along the Yangtze River Basin that are systematic across all schemes. Further improvements can be made by a super-ensemble based on more cumulus schemes and/or multiple models.

  13. Development and implementation of a seasonal model for regional air quality

    Energy Technology Data Exchange (ETDEWEB)

    Wheeler, N.; Houyoux, M.; Mathur, R.; McHenry, J.; Olerud, D.; Smith, W.T.; Vukovich, J.; Xiu, A. [MCNC-North Carolina Supercomputing Center, Research Triangle Park, NC (United States); Kasibhatla, P. [Duke Univ., Durham, NC (United States). Levine Science Research Center

    1998-12-31

    As part of its five Cooperative Agreements with the US EPA, the Southern Oxidant Study (SOS) Science Team has promoted the development and application of a unique regional air quality modeling system: The Seasonal Model for Regional Air Quality (SMRAQ). This paper describes the SMRAQ development process, the resulting model formulation, and model performance during an initial thirty-day simulation. The SMRAQ modeling system was developed using the Environmental Decision Support System (EDSS). The meteorological driver for SMRAQ is a modified version of the PSU/NCAR Mesoscale Model, MM5. Emissions are processed using the Sparse Matrix Operator Kernel Emissions (SMOKE) modeling system. The SMRAQ air quality model was built using the Multiscale Air Quality SImulation Platform (MAQSIP). The unique configuration of the SMRAQ modeling system attempts to address processes important to the formation, transport, and removal of ozone on a seasonal and regional basis. An initial thirty-day SMRAQ simulation has been performed for July 7, 1995 to August 5, 1995 and the results analyzed. On average, this initial simulation shows an average error for eight-hour average ozone ranging from 20 to 25 percent. Average bias ranges from -15 to +15 percent. Both error and bias are worse than these averages in cases where observed eight-hour average ozone concentrations exceed 100 ppb. Based on the analysis of the initial simulation, modifications are being made to the SMRAQ model and a full four-month simulation of the summer of 1995 will be carried out during the spring of 1998. The successful completion of this seasonal simulation will pave the way for future modeling studies that avoid the limitations of episodic modeling. These future studies will provide a better understanding of the ozone formation process and will yield more robust and effective control strategies for abatement of the ground-level ozone problem.

  14. Modelling the influence of peri-urban trees in the air quality of Madrid region (Spain)

    Energy Technology Data Exchange (ETDEWEB)

    Alonso, Rocio, E-mail: rocio.alonso@ciemat.es [Atmospheric Pollution Division CIEMAT, Avda., Complutense 22, 28040 Madrid (Spain); Vivanco, Marta G., E-mail: m.garcia@ciemat.es [Atmospheric Pollution Division CIEMAT, Avda., Complutense 22, 28040 Madrid (Spain); Gonzalez-Fernandez, Ignacio, E-mail: ignacio.gonzalez@ciemat.es [Atmospheric Pollution Division CIEMAT, Avda., Complutense 22, 28040 Madrid (Spain); Bermejo, Victoria, E-mail: victoria.bermejo@ciemat.es [Atmospheric Pollution Division CIEMAT, Avda., Complutense 22, 28040 Madrid (Spain); Palomino, Inmaculada, E-mail: inma.palomino@ciemat.es [Atmospheric Pollution Division CIEMAT, Avda., Complutense 22, 28040 Madrid (Spain); Garrido, Juan Luis, E-mail: juanluis.garrido@ciemat.es [Atmospheric Pollution Division CIEMAT, Avda., Complutense 22, 28040 Madrid (Spain); Elvira, Susana, E-mail: susana.elvira@ciemat.es [Atmospheric Pollution Division CIEMAT, Avda., Complutense 22, 28040 Madrid (Spain); Salvador, Pedro, E-mail: pedro.salvador@ciemat.es [Atmospheric Pollution Division CIEMAT, Avda., Complutense 22, 28040 Madrid (Spain); Artinano, Begona, E-mail: b.artinano@ciemat.es [Atmospheric Pollution Division CIEMAT, Avda., Complutense 22, 28040 Madrid (Spain)

    2011-08-15

    Tropospheric ozone (O{sub 3}) is considered one of the most important air pollutants affecting human health. The role of peri-urban vegetation in modifying O{sub 3} concentrations has been analyzed in the Madrid region (Spain) using the V200603par-rc1 version of the CHIMERE air quality model. The 3.7 version of the MM5 meteorological model was used to provide meteorological input data to the CHIMERE. The emissions were derived from the EMEP database for 2003. Land use data and the stomatal conductance model included in CHIMERE were modified according to the latest information available for the study area. Two cases were considered for the period April-September 2003: (1) actual land use and (2) a fictitious scenario where El Pardo peri-urban forest was converted to bare-soil. The results show that El Pardo forest constitutes a sink of O{sub 3} since removing this green area increased O{sub 3} levels over the modified area and over down-wind surrounding areas. - Highlights: > Role of peri-urban vegetation in modifying O{sub 3} pollution in Madrid (Spain). > The CHIMERE air quality model was adapted to Mediterranean conditions. > Preserving the peri-urban forest lowers O{sub 3} concentrations over the surrounding areas. > Evergreen broadleaf and deciduous forests removed more atmospheric O{sub 3} than conifers. - Peri-urban forests contribute to ameliorate ozone air pollution.

  15. Investigation of effects of varying model inputs on mercury deposition estimates in the Southwest US

    Directory of Open Access Journals (Sweden)

    T. Myers

    2012-04-01

    Full Text Available The Community Multiscale Air Quality (CMAQ model version 4.7.1 was used to simulate mercury wet and dry deposition for a domain covering the contiguous United States (US. The simulations used MM5-derived meteorological input fields and the US Environmental Protection Agency (EPA Clear Air Mercury Rule (CAMR emissions inventory. Using sensitivity simulations with different boundary conditions and tracer simulations, this investigation focuses on the contributions of boundary concentrations to deposited mercury in the Southwest (SW US. Concentrations of oxidized mercury species along the boundaries of the domain, in particular the upper layers of the domain, can make significant contributions to the simulated wet and dry deposition of mercury in the SW US. In order to better understand the contributions of boundary conditions to deposition, inert tracer simulations were conducted to quantify the relative amount of an atmospheric constituent transported across the boundaries of the domain at various altitudes and to quantify the amount that reaches and potentially deposits to the land surface in the SW US. Simulations using alternate sets of boundary concentrations, including estimates from global models (Goddard Earth Observing System-Chem (GEOS-Chem and the Global/Regional Atmospheric Heavy Metals (GRAHM model, and alternate meteorological input fields (for different years are analyzed in this paper. CMAQ dry deposition in the SW US is sensitive to differences in the atmospheric dynamics and atmospheric mercury chemistry parameterizations between the global models used for boundary conditions.

  16. Investigation of effects of varying model inputs on mercury deposition estimates in the Southwest US

    Directory of Open Access Journals (Sweden)

    T. Myers

    2013-01-01

    Full Text Available The Community Multiscale Air Quality (CMAQ model version 4.7.1 was used to simulate mercury wet and dry deposition for a domain covering the continental United States (US. The simulations used MM5-derived meteorological input fields and the US Environmental Protection Agency (EPA Clear Air Mercury Rule (CAMR emissions inventory. Using sensitivity simulations with different boundary conditions and tracer simulations, this investigation focuses on the contributions of boundary concentrations to deposited mercury in the Southwest (SW US. Concentrations of oxidized mercury species along the boundaries of the domain, in particular the upper layers of the domain, can make significant contributions to the simulated wet and dry deposition of mercury in the SW US. In order to better understand the contributions of boundary conditions to deposition, inert tracer simulations were conducted to quantify the relative amount of an atmospheric constituent transported across the boundaries of the domain at various altitudes and to quantify the amount that reaches and potentially deposits to the land surface in the SW US. Simulations using alternate sets of boundary concentrations, including estimates from global models (Goddard Earth Observing System-Chem (GEOS-Chem and the Global/Regional Atmospheric Heavy Metals (GRAHM model, and alternate meteorological input fields (for different years are analyzed in this paper. CMAQ dry deposition in the SW US is sensitive to differences in the atmospheric dynamics and atmospheric mercury chemistry parameterizations between the global models used for boundary conditions.

  17. Modelling SDL, Modelling Languages

    Directory of Open Access Journals (Sweden)

    Michael Piefel

    2007-02-01

    Full Text Available Today's software systems are too complex to implement them and model them using only one language. As a result, modern software engineering uses different languages for different levels of abstraction and different system aspects. Thus to handle an increasing number of related or integrated languages is the most challenging task in the development of tools. We use object oriented metamodelling to describe languages. Object orientation allows us to derive abstract reusable concept definitions (concept classes from existing languages. This language definition technique concentrates on semantic abstractions rather than syntactical peculiarities. We present a set of common concept classes that describe structure, behaviour, and data aspects of high-level modelling languages. Our models contain syntax modelling using the OMG MOF as well as static semantic constraints written in OMG OCL. We derive metamodels for subsets of SDL and UML from these common concepts, and we show for parts of these languages that they can be modelled and related to each other through the same abstract concepts.

  18. Tropospheric NO2 Columns over Northeastern North America:Comparison of CMAQ Model Simulations with GOME Satellite Measurements

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    We present comparisons of the NO2 regional Chemical Transport Model (CTM) simulations over Northeastern North America during the time period from May to September, 1998 with hourly surface NO2 observations and the NO2 columns retrieved from the GOME (Global Ozone Monitoring Experiment) satellite instrument. The model calculations were performed using the Mesoscale Meteorological Model 5 (MM5),Sparse Matrix Operator Kernal Emissions (SMOKE), and Community Multiscale Air Quality (CMAQ)modeling systems, using the emission data from the National Emissions Inventory (NEI) databases of 1996 (U.S.) and 1995 (Canada). The major objectives were to assess the performance of the CMAQ model and the accuracy of the emissions inventories as they affected the simulations of this important short-lived atmospheric species. The modeled (NCMAQ) and measured (NGOME) NO2 column amounts, as well as their temporal variations, agreed reasonably well. The absolute differences (NCMAQ-NGOME) across the domain were between ±3.0×1015 molecules cm-2, but they were less than ±1.0 × 1015 molecules cm-2 over the majority (80%) of the domain studied. The overall correlation coefficient between the measurements and the simulations was 0.75. The differences were mainly ascribed to a combination of inaccurate emission data for the CTM and the uncertainties in the GOME retrievals. Of these, the former were the more easily identifiable.

  19. Actant Models

    DEFF Research Database (Denmark)

    Poulsen, Helle

    1996-01-01

    This paper presents a functional modelling method called Actant Modelling rooted in linguistics and semiotics. Actant modelling can be integrated with Multilevel Flow Modelling (MFM) in order to give an interpretation of actants.......This paper presents a functional modelling method called Actant Modelling rooted in linguistics and semiotics. Actant modelling can be integrated with Multilevel Flow Modelling (MFM) in order to give an interpretation of actants....

  20. Modelling the models

    CERN Multimedia

    Anaïs Schaeffer

    2012-01-01

    By analysing the production of mesons in the forward region of LHC proton-proton collisions, the LHCf collaboration has provided key information needed to calibrate extremely high-energy cosmic ray models.   Average transverse momentum (pT) as a function of rapidity loss ∆y. Black dots represent LHCf data and the red diamonds represent SPS experiment UA7 results. The predictions of hadronic interaction models are shown by open boxes (sibyll 2.1), open circles (qgsjet II-03) and open triangles (epos 1.99). Among these models, epos 1.99 shows the best overall agreement with the LHCf data. LHCf is dedicated to the measurement of neutral particles emitted at extremely small angles in the very forward region of LHC collisions. Two imaging calorimeters – Arm1 and Arm2 – take data 140 m either side of the ATLAS interaction point. “The physics goal of this type of analysis is to provide data for calibrating the hadron interaction models – the well-known &...

  1. Modelling Practice

    DEFF Research Database (Denmark)

    2011-01-01

    This chapter deals with the practicalities of building, testing, deploying and maintaining models. It gives specific advice for each phase of the modelling cycle. To do this, a modelling framework is introduced which covers: problem and model definition; model conceptualization; model data...... requirements; model construction; model solution; model verification; model validation and finally model deployment and maintenance. Within the adopted methodology, each step is discussedthrough the consideration of key issues and questions relevant to the modelling activity. Practical advice, based on many...... years of experience is providing in directing the reader in their activities.Traps and pitfalls are discussed and strategies also given to improve model development towards “fit-for-purpose” models. The emphasis in this chapter is the adoption and exercise of a modelling methodology that has proven very...

  2. Budget of tropospheric ozone during TOPSE from two chemical transport models

    Science.gov (United States)

    Emmons, L. K.; Hess, P.; Klonecki, A.; Tie, X.; Horowitz, L.; Lamarque, J.-F.; Kinnison, D.; Brasseur, G.; Atlas, E.; Browell, E.; Cantrell, C.; Eisele, F.; Mauldin, R. L.; Merrill, J.; Ridley, B.; Shetter, R.

    2003-04-01

    The tropospheric ozone budget during the Tropospheric Ozone Production about the Spring Equinox (TOPSE) campaign has been studied using two chemical transport models (CTMs): HANK and the Model of Ozone and Related chemical Tracers, version 2 (MOZART-2). The two models have similar chemical schemes but use different meteorological fields, with HANK using MM5 (Pennsylvania State University, National Center for Atmospheric Research Mesoscale Modeling System) and MOZART-2 driven by European Centre for Medium-Range Weather Forecasts (ECMWF) fields. Both models simulate ozone in good agreement with the observations but underestimate NOx. The models indicate that in the troposphere, averaged over the northern middle and high latitudes, chemical production of ozone drives the increase of ozone seen in the spring. Both ozone gross chemical production and loss increase greatly over the spring months. The in situ production is much larger than the net stratospheric input, and the deposition and horizontal fluxes are relatively small in comparison to chemical destruction. The net production depends sensitively on the concentrations of H2O, HO2 and NO, which differ slightly in the two models. Both models underestimate the chemical production calculated in a steady state model using TOPSE measurements, but the chemical loss rates agree well. Measures of the stratospheric influence on tropospheric ozone in relation to in situ ozone production are discussed. Two different estimates of the stratospheric fraction of O3 in the Northern Hemisphere troposphere indicate it decreases from 30-50% in February to 15-30% in June. A sensitivity study of the effect of a perturbation in the vertical flux on tropospheric ozone indicates the contribution from the stratosphere is approximately 15%.

  3. A regional climate palaeosimulation for Europe in the period 1500–1990 – Part 1: Model validation

    Directory of Open Access Journals (Sweden)

    J. J. Gómez-Navarro

    2013-04-01

    Full Text Available We present and analyse a high-resolution regional climate palaeosimulation encompassing the European region for the period 1500–1990. We use the regional model MM5 coupled to the global model ECHO-G. Both models were driven by reconstructions of three external factors: greenhouse gas concentrations, Total Solar Irradiance and volcanic activity. The simulation has been assessed in a recent period by comparing the model results with the Climate Research Unit (CRU database. The results show that although the regional model is tightly driven by the boundary conditions, it is able to improve the reliability of the simulations, narrowing the differences to the observations, especially in areas of complex topography. Additionally, the evolution of the spatial distributions of temperature and precipitation through the last five centuries has been analysed. The mean values of temperature reflects the influence of the external forcings but, contrary to the results obtained under climate change scenario conditions, we found that higher-order momenta of the probability distribution of seasonal temperature and precipitation are hardly affected by changes in the external forcings

  4. Inter-comparison of 10-year precipitation simulated by several RCMs for Asia

    Science.gov (United States)

    Feng, Jinming; Fu, Congbin

    2006-12-01

    In phase II of the Regional Climate Model Inter-comparison Project (RMIP) for Asia, the regional climate has been simulated for July 1988 through December 1998 by five regional climate models and one global variable resolution model. Comparison of the 10-year simulated precipitation with the observations was carried out. The results show that most models have the capacity to reproduce the basic spatial pattern of precipitation for Asia, and the main rainbelt can be reproduced by most models, but there are distinctions in the location and the intensity. Most models overestimate the precipitation over most continental regions. Interannual variability of the precipitation can also be basically simulated, while differences exist between various models and the observations. The biases in the stream field are important reasons behind the simulation errors of the Regional Climate Models (RCMs). The cumulus scheme and land surface process have large influences on the precipitation simulation. Generally, the Grell cumulus scheme produces more precipitation than the Kuo scheme.

  5. Inter-Comparison of 10-year Precipitation Simulated by Several RCMs for Asia

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    In phase Ⅱ of the Regional Climate Model Inter-comparison Project (RMIP) for Asia, the regional climate has been simulated for July 1988 through December 1998 by five regional climate models and one global variable resolution model. Comparison of the 10-year simulated precipitation with the observations was carried out. The results show that most models have the capacity to reproduce the basic spatial pattern of precipitation for Asia, and the main rainbelt can be reproduced by most models, but there are distinctions in the location and the intensity. Most models overestimate the precipitation over most continental regions. Interannual variability of the precipitation can also be basically simulated, while differences exist between various models and the observations. The biases in the stream field are important reasons behind the simulation errors of the Regional Climate Models (RCMs). The cumulus scheme and land surface process have large influences on the precipitation simulation. Generally, the Grell cumulus scheme produces more precipitation than the Kuo scheme.

  6. Promoting Models

    Science.gov (United States)

    Li, Qin; Zhao, Yongxin; Wu, Xiaofeng; Liu, Si

    There can be multitudinous models specifying aspects of the same system. Each model has a bias towards one aspect. These models often override in specific aspects though they have different expressions. A specification written in one model can be refined by introducing additional information from other models. The paper proposes a concept of promoting models which is a methodology to obtain refinements with support from cooperating models. It refines a primary model by integrating the information from a secondary model. The promotion principle is not merely an academic point, but also a reliable and robust engineering technique which can be used to develop software and hardware systems. It can also check the consistency between two specifications from different models. A case of modeling a simple online shopping system with the cooperation of the guarded design model and CSP model illustrates the practicability of the promotion principle.

  7. Cadastral Modeling

    DEFF Research Database (Denmark)

    Stubkjær, Erik

    2005-01-01

    Modeling is a term that refers to a variety of efforts, including data and process modeling. The domain to be modeled may be a department, an organization, or even an industrial sector. E-business presupposes the modeling of an industrial sector, a substantial task. Cadastral modeling compares to...

  8. Sensitivity of meteorological input and soil properties in simulating aerosols (dust, PM10, and BC) using CHIMERE chemistry transport model

    Indian Academy of Sciences (India)

    Nishi Srivastava; S K Satheesh; Nadège Blond

    2014-08-01

    The objective of this study is to evaluate the ability of a European chemistry transport model, ‘CHIMERE’ driven by the US meteorological model MM5, in simulating aerosol concentrations [dust, PM10 and black carbon (BC)] over the Indian region. An evaluation of a meteorological event (dust storm); impact of change in soil-related parameters and meteorological input grid resolution on these aerosol concentrations has been performed. Dust storm simulation over Indo-Gangetic basin indicates ability of the model to capture dust storm events. Measured (AERONET data) and simulated parameters such as aerosol optical depth (AOD) and Angstrom exponent are used to evaluate the performance of the model to capture the dust storm event. A sensitivity study is performed to investigate the impact of change in soil characteristics (thickness of the soil layer in contact with air, volumetric water, and air content of the soil) and meteorological input grid resolution on the aerosol (dust, PM10, BC) distribution. Results show that soil parameters and meteorological input grid resolution have an important impact on spatial distribution of aerosol (dust, PM10, BC) concentrations.

  9. Model Warehouse

    Institute of Scientific and Technical Information of China (English)

    2003-01-01

    This paper puts forward a new conception:model warehouse,analyzes the reason why model warehouse appears and introduces the characteristics and architecture of model warehouse.Last,this paper points out that model warehouse is an important part of WebGIS.

  10. Estimation of urban mixed layer height in Zanjan using LIDAR observations and numerical modeling

    Indian Academy of Sciences (India)

    A A Bidokhti; M Khoshsima; S Sabetghadam; H M Khalesifard

    2008-12-01

    Air pollution predictions often require the height of atmospheric mixed layer in time especially in big cities. Here, the variation of the height of this layer is estimated from direct measurements and also from a numerical forecast model with a high resolution boundary layer scheme. The height of the daytime mixed layer for the city of Zanjan (48.5°N, 36.7°E, 1700 m above sea level)is measured using a LIDAR (532 nm)system, which works based on aerosols scattering of laser light. The mixed layer height () for Zanjan city, well above mean sea level compared to other major cities in the world,is found to be between 1.4 km typically in spring and 2.2 km in summer, for synoptic calm conditions. Also, the MM5 forecast model with a proper boundary layer scheme (MRF)is used to estimate which shows rather good agreement with direct observations using the LIDAR system. The entrainment zone of the mixed layer was also found to undergo some occasional temporal growth that may be attributed to shear instability that led to more mixed layer growth.

  11. The importance of high spatial resolution for the performance of atmospheric chemistry-transport models

    Science.gov (United States)

    Mantzius Hansen, Kaj

    2010-05-01

    We have investigated the importance of spatial resolution for the performance of the Danish Eulerian Hemispheric Model (DEHM), a state-of-the-art atmospheric chemistry-transport model covering the majority of the Northern Hemisphere with a horizontal grid resolution of 150 km X 150 km. DEHM has 29 vertical layers in terrain-following sigma-coordinates extending up to a height of 100 hPa. Two-way nesting options with a nesting factor of three can be applied with higher resolution over a limited area of the model. At present the model can be run without nests or with one, two or three nests, each with resolutions of 50 km X 50 km, 16.7 km X 16.7 km, and 5.6 km X 5.6 km, respectively. The model includes a comprehensive chemistry scheme with more than 100 reactions and 67 atmospheric constituents, of which 4 relate to primary particulates (PM2.5, PM10, TSP and sea salt), other species are SOx, NOx, NHx, VOCs, and secondary inorganic particulates. DEHM is driven by meteorological data from the numerical weather prediction model MM5v3. Three simulations were performed with DEHM: one simulation with only the mother domain, one simulation with one nest over Europe, and one simulation with an additional nest covering Denmark and surrounding countries. All three simulations cover the period from 1989 to 2006. The predicted concentrations were evaluated against measurements from the EMEP monitoring network. Only sites within the innermost nest were included in the evaluation and the evaluations of the three simulations were compared to test the influence of spatial resolution on the performance of the model.

  12. Advances in Disaster Modeling, Simulation and Visualization for Sandstorm Risk Management in North China

    Directory of Open Access Journals (Sweden)

    Hang Lei

    2012-05-01

    Full Text Available Dust storms in North China result in high concentrations of airborne dust particles, which cause detrimental effects on human health as well as social and economic losses and environmental degradation. To investigate the impact of land surface processes on dust storms, we simulate two dust storm events in North China during spring 2002 using two versions of a dust storm prediction system developed by the Institute for Atmospheric Physics (IAP in Beijing, China. The primary difference between the IAP Sandstorm Prediction System (IAPS 1.0 and more recent version (IAPS 2.0 is the land surface modeling. IAPS 1.0 is based on the Oregon State University (OSU land surface model, whereas the latest version of the dust storm prediction (IAPS 2.0 uses NOAH land surface schemes for land surface modeling within a meteorological model, MM5. This work investigates whether the improved land surface modeling affects modeling of sandstorms. It is shown that an integrated sandstorm management system can be used to aid the following tasks: ensure sandstorm monitoring and warning; incorporate weather forecasts; ascertain the risk of a sandstorm disaster; integrate multiple technologies (for example, GIS, remote sensing, and information processing technology; track the progress of the storm in real-time; exhibit flexibility, accuracy and reliability (by using multiple sources of data, including in-situ meteorological observations; and monitor PM10 and PM2.5 dust concentrations in airborne dustfalls. The results indicate that with the new land surface scheme, the simulation of soil moisture is greatly improved, leading to a better estimate of the threshold frictional velocity, a key parameter for the estimating surface dust emissions. In this study, we also discuss specific mechanisms by which land surface processes affect dust storm modeling and make recommendations for further improvements to numerical dust storm simulations.

  13. A physical model to estimate snowfall over land using AMSU-B observations

    Science.gov (United States)

    Kim, Min-Jeong; Weinman, J. A.; Olson, W. S.; Chang, D.-E.; Skofronick-Jackson, G.; Wang, J. R.

    2008-05-01

    In this study, we present a physical model to retrieve snowfall rate over land using brightness temperature observations from NOAA's Advanced Microwave Sounder Unit-B (AMSU-B) at 89 GHz, 150 GHz, 183.3 ± 1 GHz, 183.3 ± 3 GHz, and 183.3 ± 7 GHz. The retrieval model is applied to the New England blizzard of 5 March 2001 which deposited about 75 cm of snow over much of Vermont, New Hampshire, and northern New York. In this physical model, prior retrieval assumptions about snowflake shape, particle size distributions, environmental conditions, and optimization methodology have been updated. Here, single scattering parameters for snow particles are calculated with the discrete-dipole approximation (DDA) method instead of assuming spherical shapes. Five different snow particle models are considered. Snow particle size distributions are assumed to vary with air temperature and to follow aircraft measurements described by previous studies. Brightness temperatures at AMSU-B frequencies for the New England blizzard are calculated using these DDA calculated single scattering parameters and particle size distributions. The vertical profiles of pressure, temperature, relative humidity and hydrometeors are provided by MM5 model simulations. These profiles are treated as the a priori database in the Bayesian retrieval algorithm. In algorithm applications to the blizzard data, calculated brightness temperatures associated with selected database profiles agree with AMSU-B observations to within about ±5 K at all five frequencies. Retrieved snowfall rates compare favorably with the near-concurrent National Weather Service (NWS) radar reflectivity measurements. The relationships between the NWS radar measured reflectivities Ze and retrieved snowfall rate R for a given snow particle model are derived by a histogram matching technique. All of these Ze-R relationships fall in the range of previously established Ze-R relationships for snowfall. This suggests that the current physical

  14. Constitutive Models

    DEFF Research Database (Denmark)

    2011-01-01

    procedure is introduced for the analysis and solution of property models. Models that capture and represent the temperature dependent behaviour of physical properties are introduced, as well as equation of state models (EOS) such as the SRK EOS. Modelling of liquid phase activity coefficients are also......This chapter presents various types of constitutive models and their applications. There are 3 aspects dealt with in this chapter, namely: creation and solution of property models, the application of parameter estimation and finally application examples of constitutive models. A systematic...... covered, illustrating several models such as the Wilson equation and NRTL equation, along with their solution strategies. A section shows how to use experimental data to regress the property model parameters using a least squares approach. A full model analysis is applied in each example that discusses...

  15. Model cities

    OpenAIRE

    Batty, M.

    2007-01-01

    The term ?model? is now central to our thinking about how weunderstand and design cities. We suggest a variety of ways inwhich we use ?models?, linking these ideas to Abercrombie?sexposition of Town and Country Planning which represented thestate of the art fifty years ago. Here we focus on using models asphysical representations of the city, tracing the development ofsymbolic models where the focus is on simulating how functiongenerates form, to iconic models where the focus is on representi...

  16. Model theory

    CERN Document Server

    Chang, CC

    2012-01-01

    Model theory deals with a branch of mathematical logic showing connections between a formal language and its interpretations or models. This is the first and most successful textbook in logical model theory. Extensively updated and corrected in 1990 to accommodate developments in model theoretic methods - including classification theory and nonstandard analysis - the third edition added entirely new sections, exercises, and references. Each chapter introduces an individual method and discusses specific applications. Basic methods of constructing models include constants, elementary chains, Sko

  17. NWP prediction at ESRL/GSD: Latest developments and applications for physics parameterizations

    Science.gov (United States)

    Grell, Georg; Olson, Joseph; Benjamin, Stan; Smirnova, Tanya; Kenyon, Jaymes; James, Eric; Zhang, Li; Ahmadov, Ravan; Brown, John

    2017-04-01

    A summary of ESRL/GSD physics parameterization modeling efforts will be presented on both regional and global scale. The physics packages developed at ESRL include a scale-aware parameterization of subgrid cloudiness feedback to radiation (coupled PBL, microphysics, radiation, shallow convection) and the Grell-Freitas scale and aerosol aware convective parameterization. ESRL also has been developing improved inline chemistry/aerosol techniques being applied in both regional and global models. Increasingly effective reforecasting has been successfully applied to global models by ESRL for short and medium range NWP, and at subseasonal time scales using, in part, advanced physics adapted from the regional scale. The mesoscale physics suite in the HRRR/RAP model is now in preparation for testing with NOAA's upcoming FV3 global model.

  18. Event Modeling

    DEFF Research Database (Denmark)

    Bækgaard, Lars

    2001-01-01

    The purpose of this chapter is to discuss conceptual event modeling within a context of information modeling. Traditionally, information modeling has been concerned with the modeling of a universe of discourse in terms of information structures. However, most interesting universes of discourse...... are dynamic and we present a modeling approach that can be used to model such dynamics. We characterize events as both information objects and change agents (Bækgaard 1997). When viewed as information objects events are phenomena that can be observed and described. For example, borrow events in a library can...

  19. Event Modeling

    DEFF Research Database (Denmark)

    Bækgaard, Lars

    2001-01-01

    The purpose of this chapter is to discuss conceptual event modeling within a context of information modeling. Traditionally, information modeling has been concerned with the modeling of a universe of discourse in terms of information structures. However, most interesting universes of discourse...... are dynamic and we present a modeling approach that can be used to model such dynamics.We characterize events as both information objects and change agents (Bækgaard 1997). When viewed as information objects events are phenomena that can be observed and described. For example, borrow events in a library can...

  20. Weather modeling for hazard and consequence assessment operations during the 2006 Winter Olympic Games

    Science.gov (United States)

    Hayes, P.; Trigg, J. L.; Stauffer, D.; Hunter, G.; McQueen, J.

    2006-05-01

    modelers on the meteorology team. Some of the Olympic venues were located in the mountains to the west of Torino, while the rest were located on the relatively flat plain in and around the cities of Pinerolo and Torino to the east. DTRA partners at Pennsylvania State University (PSU) and the U.S. National Center for Atmospheric Research (NCAR) established data collection and assimilation, and forecast modeling processes that used special weather station observations provided by the Area Previsione e Monitoraggio Ambientale of Italy's ARPA Piemonte. At PSU a version of the MM5 was especially prepared to use observation data to forecast weather in a four-nest configuration. Two other DTRA partners provided independent weather forecast models against which the PSU model data were compared. The U.S. Air Force Weather Agency provided its MM5 forecast model data and the U.S. National Oceanic and Atmospheric Administration's National Centers for Environmental Prediction provided data from a special version of their WRF model. The project produced many opportunities to improve the modeling and forecasting capability at DTRA. DTRA and its partners plan to expand upon this experience during upcoming field tests, and to further improve and expand the capability to provide accurate high-resolution weather forecast information to hazard and consequence assessment operations.

  1. Numerical Simulation of Precipitation Enhancement by Stratiform Cloud Seeding Using a Mesoscale Model%层状云系催化增雨的中尺度模拟研究

    Institute of Scientific and Technical Information of China (English)

    赵震; 雷恒池

    2012-01-01

    利用PSU/NCAR中尺度模式MM5研究层状云碘化银催化后的区域外效应.在MM5中双参数显式云物理方案基础上,采用显式方法加入碘化银粒子的成核机制,建立碘化银粒子比含水量和数浓度预报方程.通过增加催化过程的程序模块,建立起一个中尺度人工催化系统.采用三重嵌套到3.3 km格距模拟了一次层状云系大范围降水,此个例-5℃到-10℃上碘化银催化试验结果表明碘化银在高空风的作用下向下风方输送并影响云内的微物理过程,碘化银持续作用时间为3h.大多数碘化银主要起凝华核作用,催化后冰晶增加主要靠凝华过程.催化后3h内在下风方区域80 km到240 km有10%~30%的增雨,出现催化区域外效应.%The Fifth-Generation Penn State/NCAR Mesoscale Model (MM5) was used to investigate the extra-area effects of silver iodide (Agl) seeding on stratiform clouds at the supercooled layer. A bulk two-moment microphysical scheme and the new software package for Agl were incorporated into MM5. Extra conservation equations were applied to trace the seeding agent, which was transported along the flow field and interacted with the supercooled cloud fields. In this study, the model was run for widespread precipitation caused by a stratiform cloud system using three nested grids, with a 3.3 km X 3.3 km horizontal resolution in the finest grid. The model results showed that seeding with Agl at the -5 ℃ to -10℃ levels had microphysical effects on the simulated clouds and that the simulation produced a seeding effect that lasted 3 h longer because of transport of the seeding agent by upper-level winds. Most of the Agl particles acted as deposition nuclei, and the deposition nucleation process contributed most to additional cloud ice formation. The results showed that more precipitation results from seeded than unseeded clouds, and the precipitation was redistributed downwind of the target. Augmented precipitation (varying

  2. Numerical models

    Digital Repository Service at National Institute of Oceanography (India)

    Unnikrishnan, A; Manoj, N.T.

    Various numerical models used to study the dynamics and horizontal distribution of salinity in Mandovi-Zuari estuaries, Goa, India is discussed in this chapter. Earlier, a one-dimensional network model was developed for representing the complex...

  3. Comparison of mean properties of simulated convection in a cloud-resolving model with those produced by cumulus parameterization

    Energy Technology Data Exchange (ETDEWEB)

    Dudhia, J.; Parsons, D.B. [National Center for Atmospheric Research, Boulder, CO (United States)

    1996-04-01

    An Intensive Observation Period (IOP) of the Atmospheric Radiation Measurement (ARM) Program took place at the Southern Great Plains (SGP) Cloud and Radiation Testbed (CART) site from June 16-26, 1993. The National Center for Atmospheric Research (NCAR)/Penn State Mesoscale Model (MM5) has been used to simulate this period on a 60-km domain with 20- and 6.67-km nests centered on Lamont, Oklahoma. Simulations are being run with data assimilation by the nudging technique to incorporate upper-air and surface data from a variety of platforms. The model maintains dynamical consistency between the fields, while the data correct for model biases that may occur during long-term simulations and provide boundary conditions. For the work reported here the Mesoscale Atmospheric Prediction System (MAPS) of the National Ocean and Atmospheric Administration (NOAA) 3-hourly analyses were used to drive the 60-km domain while the inner domains were unforced. A continuous 10-day period was simulated.

  4. Assimilation of Doppler weather radar observations in a mesoscale model for the prediction of rainfall associated with mesoscale convective systems

    Indian Academy of Sciences (India)

    S Abhilash; Someshwar Das; S R Kalsi; M Das Gupta; K Mohankumar; J P George; S K Banerjee; S B Thampi; D Pradhan

    2007-08-01

    Obtaining an accurate initial state is recognized as one of the biggest challenges in accurate model prediction of convective events. This work is the first attempt in utilizing the India Meteorological Department (IMD) Doppler radar data in a numerical model for the prediction of mesoscale convective complexes around Chennai and Kolkata. Three strong convective events both over Chennai and Kolkata have been considered for the present study. The simulation experiments have been carried out using fifth-generation Pennsylvania State University–National Center for Atmospheric Research (PSU–NCAR) mesoscale model (MM5) version 3.5.6. The variational data assimilation approach is one of the most promising tools available for directly assimilating the mesoscale observations in order to improve the initial state. The horizontal wind derived from the DWR has been used alongwith other conventional and non-conventional data in the assimilation system. The preliminary results from the three dimensional variational (3DVAR) experiments are encouraging. The simulated rainfall has also been compared with that derived from the Tropical Rainfall Measuring Mission (TRMM) satellite. The encouraging result from this study can be the basis for further investigation of the direct assimilation of radar reflectivity data in 3DVAR system. The present study indicates that Doppler radar data assimilation improves the initial field and enhances the Quantitative Precipitation Forecasting (QPF) skill.

  5. Computable models

    CERN Document Server

    Turner, Raymond

    2009-01-01

    Computational models can be found everywhere in present day science and engineering. In providing a logical framework and foundation for the specification and design of specification languages, Raymond Turner uses this framework to introduce and study computable models. In doing so he presents the first systematic attempt to provide computational models with a logical foundation. Computable models have wide-ranging applications from programming language semantics and specification languages, through to knowledge representation languages and formalism for natural language semantics. They are al

  6. MODELING CONSCIOUSNESS

    OpenAIRE

    Taylor, J G

    2009-01-01

    We present tentative answers to three questions: firstly, what is to be assumed about the structure of the brain in attacking the problem of modeling consciousness; secondly, what is it about consciousness that is attempting to be modeled; and finally, what is taken on board the modeling enterprise, if anything, from the vast works by philosophers about the nature of mind.

  7. Zeebrugge Model

    DEFF Research Database (Denmark)

    Sclütter, Flemming; Frigaard, Peter; Liu, Zhou

    This report presents the model test results on wave run-up on the Zeebrugge breakwater under the simulated prototype storms. The model test was performed in January 2000 at the Hydraulics & Coastal Engineering Laboratory, Aalborg University. The detailed description of the model is given...

  8. Interface models

    DEFF Research Database (Denmark)

    Ravn, Anders P.; Staunstrup, Jørgen

    1994-01-01

    This paper proposes a model for specifying interfaces between concurrently executing modules of a computing system. The model does not prescribe a particular type of communication protocol and is aimed at describing interfaces between both software and hardware modules or a combination of the two....... The model describes both functional and timing properties of an interface...

  9. Constitutive Models

    DEFF Research Database (Denmark)

    2011-01-01

    This chapter presents various types of constitutive models and their applications. There are 3 aspects dealt with in this chapter, namely: creation and solution of property models, the application of parameter estimation and finally application examples of constitutive models. A systematic...

  10. Model Experiments and Model Descriptions

    Science.gov (United States)

    Jackman, Charles H.; Ko, Malcolm K. W.; Weisenstein, Debra; Scott, Courtney J.; Shia, Run-Lie; Rodriguez, Jose; Sze, N. D.; Vohralik, Peter; Randeniya, Lakshman; Plumb, Ian

    1999-01-01

    The Second Workshop on Stratospheric Models and Measurements Workshop (M&M II) is the continuation of the effort previously started in the first Workshop (M&M I, Prather and Remsberg [1993]) held in 1992. As originally stated, the aim of M&M is to provide a foundation for establishing the credibility of stratospheric models used in environmental assessments of the ozone response to chlorofluorocarbons, aircraft emissions, and other climate-chemistry interactions. To accomplish this, a set of measurements of the present day atmosphere was selected. The intent was that successful simulations of the set of measurements should become the prerequisite for the acceptance of these models as having a reliable prediction for future ozone behavior. This section is divided into two: model experiment and model descriptions. In the model experiment, participant were given the charge to design a number of experiments that would use observations to test whether models are using the correct mechanisms to simulate the distributions of ozone and other trace gases in the atmosphere. The purpose is closely tied to the needs to reduce the uncertainties in the model predicted responses of stratospheric ozone to perturbations. The specifications for the experiments were sent out to the modeling community in June 1997. Twenty eight modeling groups responded to the requests for input. The first part of this section discusses the different modeling group, along with the experiments performed. Part two of this section, gives brief descriptions of each model as provided by the individual modeling groups.

  11. Scalable Models Using Model Transformation

    Science.gov (United States)

    2008-07-13

    and the following companies: Agilent, Bosch, HSBC , Lockheed-Martin, National Instruments, and Toyota. Scalable Models Using Model Transformation...parametrization, and workflow automation. (AFRL), the State of California Micro Program, and the following companies: Agi- lent, Bosch, HSBC , Lockheed

  12. Cadastral Modeling

    DEFF Research Database (Denmark)

    Stubkjær, Erik

    2005-01-01

    to the modeling of an industrial sector, as it aims at rendering the basic concepts that relate to the domain of real estate and the pertinent human activities. The palpable objects are pieces of land and buildings, documents, data stores and archives, as well as persons in their diverse roles as owners, holders...... to land. The paper advances the position that cadastral modeling has to include not only the physical objects, agents, and information sets of the domain, but also the objectives or requirements of cadastral systems.......Modeling is a term that refers to a variety of efforts, including data and process modeling. The domain to be modeled may be a department, an organization, or even an industrial sector. E-business presupposes the modeling of an industrial sector, a substantial task. Cadastral modeling compares...

  13. A Heavy Sea Fog Event over the Yellow Sea in March 2005:Analysis and Numerical Modeling

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    In this paper, a heavy sea fog episode that occurred over the Yellow Sea on 9 March 2005 is investigated.The sea fog patch, with a spatial scale of several hundred kilometers at its mature stage, reduced visibility along the Shandong Peninsula coast to 100 m or much less at some sites. Satellite images, surface observations and soundings at islands and coasts, and analyses from the Japan Meteorology Agency (JMA) are used to describe and analyze this event. The analysis indicates that this sea fog can be categorized as advection cooling fog. The main features of this sea fog including fog area and its movement are reasonably reproduced by the Fifth-generation Pennsylvania State University/National Center for Atmospheric Research Mesoscale Model (MM5). Model results suggest that the formation and evolution of this event can be outlined as:(1) southerly warm/moist advection of low-level air resulted in a strong sea-surface-based inversion with a thickness of about 600 m; (2) when the inversion moved from the warmer East Sea to the colder Yellow Sea, a thermal internal boundary layer (TIBL) gradually formed at the base of the inversion while the sea fog grew in response to cooling and moistening by turbulence mixing; (3) the sea fog developed as the TIBL moved northward and (4) strong northerly cold and dry wind destroyed the TIBL and dissipated the sea fog. The principal findings of this study are that sea fog forms in response to relatively persistent southerly warm/moist wind and a cold sea surface, and that turbulence mixing by wind shear is the primary mechanism for the cooling and moistening the marine layer. In addition, the study of sensitivity experiments indicates that deterministic numerical modeling offers a promising approach to the prediction of sea fog over the Yellow Sea but it may be more efficient to consider ensemble numerical modeling because of the extreme sensitivity to model input.

  14. Modelling in Business Model design

    NARCIS (Netherlands)

    Simonse, W.L.

    2013-01-01

    It appears that business model design might not always produce a design or model as the expected result. However when designers are involved, a visual model or artefact is produced. To assist strategic managers in thinking about how they can act, the designers challenge is to combine strategy and

  15. Intercomparison of the community multiscale air quality model and CALGRID using process analysis.

    Science.gov (United States)

    O'Neill, Susan M; Lamb, Brian K

    2005-08-01

    This study was designed to examine the similarities and differences between two advanced photochemical air quality modeling systems: EPA Models-3/CMAQ and CALGRID/CALMET. Both modeling systems were applied to an ozone episode that occurred along the I-5 urban corridor in western Washington and Oregon during July 11-14, 1996. Both models employed the same modeling domain and used the same detailed gridded emission inventory. The CMAQ model was run using both the CB-IV and RADM2 chemical mechanisms, while CALGRID was used with the SAPRC-97 chemical mechanism. Outputfrom the Mesoscale Meteorological Model (MM5) employed with observational nudging was used in both models. The two modeling systems, representing three chemical mechanisms and two sets of meteorological inputs, were evaluated in terms of statistical performance measures for both 1- and 8-h average observed ozone concentrations. The results showed that the different versions of the systems were more similar than different, and all versions performed well in the Portland region and downwind of Seattle but performed poorly in the more rural region north of Seattle. Improving the meteorological input into the CALGRID/CALMET system with planetary boundary layer (PBL) parameters from the Models-3/CMAQ meteorology preprocessor (MCIP) improved the performance of the CALGRID/CALMET system. The 8-h ensemble case was often the best performer of all the cases indicating that the models perform better over longer analysis periods. The 1-h ensemble case, derived from all runs, was not necessarily an improvement over the five individual cases, but the standard deviation about the mean provided a measure of overall modeling uncertainty. Process analysis was applied to examine the contribution of the individual processes to the species conservation equation. The process analysis results indicated that the two modeling systems arrive at similar solutions by very different means. Transport rates are faster and exhibit

  16. Climate Models

    Science.gov (United States)

    Druyan, Leonard M.

    2012-01-01

    Climate models is a very broad topic, so a single volume can only offer a small sampling of relevant research activities. This volume of 14 chapters includes descriptions of a variety of modeling studies for a variety of geographic regions by an international roster of authors. The climate research community generally uses the rubric climate models to refer to organized sets of computer instructions that produce simulations of climate evolution. The code is based on physical relationships that describe the shared variability of meteorological parameters such as temperature, humidity, precipitation rate, circulation, radiation fluxes, etc. Three-dimensional climate models are integrated over time in order to compute the temporal and spatial variations of these parameters. Model domains can be global or regional and the horizontal and vertical resolutions of the computational grid vary from model to model. Considering the entire climate system requires accounting for interactions between solar insolation, atmospheric, oceanic and continental processes, the latter including land hydrology and vegetation. Model simulations may concentrate on one or more of these components, but the most sophisticated models will estimate the mutual interactions of all of these environments. Advances in computer technology have prompted investments in more complex model configurations that consider more phenomena interactions than were possible with yesterday s computers. However, not every attempt to add to the computational layers is rewarded by better model performance. Extensive research is required to test and document any advantages gained by greater sophistication in model formulation. One purpose for publishing climate model research results is to present purported advances for evaluation by the scientific community.

  17. Mathematical modelling

    CERN Document Server

    2016-01-01

    This book provides a thorough introduction to the challenge of applying mathematics in real-world scenarios. Modelling tasks rarely involve well-defined categories, and they often require multidisciplinary input from mathematics, physics, computer sciences, or engineering. In keeping with this spirit of modelling, the book includes a wealth of cross-references between the chapters and frequently points to the real-world context. The book combines classical approaches to modelling with novel areas such as soft computing methods, inverse problems, and model uncertainty. Attention is also paid to the interaction between models, data and the use of mathematical software. The reader will find a broad selection of theoretical tools for practicing industrial mathematics, including the analysis of continuum models, probabilistic and discrete phenomena, and asymptotic and sensitivity analysis.

  18. Turbulence Model

    DEFF Research Database (Denmark)

    Nielsen, Mogens Peter; Shui, Wan; Johansson, Jens

    2011-01-01

    In this report a new turbulence model is presented.In contrast to the bulk of modern work, the model is a classical continuum model with a relatively simple constitutive equation. The constitutive equation is, as usual in continuum mechanics, entirely empirical. It has the usual Newton or Stokes...... term with stresses depending linearly on the strain rates. This term takes into account the transfer of linear momentum from one part of the fluid to another. Besides there is another term, which takes into account the transfer of angular momentum. Thus the model implies a new definition of turbulence....... The model is in a virgin state, but a number of numerical tests have been carried out with good results. It is published to encourage other researchers to study the model in order to find its merits and possible limitations....

  19. Mathematical modelling

    DEFF Research Database (Denmark)

    Blomhøj, Morten

    2004-01-01

    Developing competences for setting up, analysing and criticising mathematical models are normally seen as relevant only from and above upper secondary level. The general belief among teachers is that modelling activities presuppose conceptual understanding of the mathematics involved. Mathematical...... modelling, however, can be seen as a practice of teaching that place the relation between real life and mathematics into the centre of teaching and learning mathematics, and this is relevant at all levels. Modelling activities may motivate the learning process and help the learner to establish cognitive...... roots for the construction of important mathematical concepts. In addition competences for setting up, analysing and criticising modelling processes and the possible use of models is a formative aim in this own right for mathematics teaching in general education. The paper presents a theoretical...

  20. Spherical models

    CERN Document Server

    Wenninger, Magnus J

    2012-01-01

    Well-illustrated, practical approach to creating star-faced spherical forms that can serve as basic structures for geodesic domes. Complete instructions for making models from circular bands of paper with just a ruler and compass. Discusses tessellation, or tiling, and how to make spherical models of the semiregular solids and concludes with a discussion of the relationship of polyhedra to geodesic domes and directions for building models of domes. "". . . very pleasant reading."" - Science. 1979 edition.

  1. Zeebrugge Model

    DEFF Research Database (Denmark)

    Liu, Zhou; Frigaard, Peter

    This report presents the model on wave run-up and run-down on the Zeebrugge breakwater under short-crested oblique wave attacks. The model test was performed in March-April 2000 at the Hydraulics & Coastal Engineering Laboratory, Aalborg University.......This report presents the model on wave run-up and run-down on the Zeebrugge breakwater under short-crested oblique wave attacks. The model test was performed in March-April 2000 at the Hydraulics & Coastal Engineering Laboratory, Aalborg University....

  2. Stream Modelling

    DEFF Research Database (Denmark)

    Vestergaard, Kristian

    the engineers, but as the scale and the complexity of the hydraulic works increased, the mathematical models became so complex that a mathematical solution could not be obtained. This created a demand for new methods and again the experimental investigation became popular, but this time as measurements on small......-scale models. But still the scale and complexity of hydraulic works were increasing, and soon even small-scale models reached a natural limit for some applications. In the mean time the modern computer was developed, and it became possible to solve complex mathematical models by use of computer-based numerical...

  3. Ventilation Model

    Energy Technology Data Exchange (ETDEWEB)

    V. Chipman

    2002-10-05

    The purpose of the Ventilation Model is to simulate the heat transfer processes in and around waste emplacement drifts during periods of forced ventilation. The model evaluates the effects of emplacement drift ventilation on the thermal conditions in the emplacement drifts and surrounding rock mass, and calculates the heat removal by ventilation as a measure of the viability of ventilation to delay the onset of peak repository temperature and reduce its magnitude. The heat removal by ventilation is temporally and spatially dependent, and is expressed as the fraction of heat carried away by the ventilation air compared to the fraction of heat produced by radionuclide decay. One minus the heat removal is called the wall heat fraction, or the remaining amount of heat that is transferred via conduction to the surrounding rock mass. Downstream models, such as the ''Multiscale Thermohydrologic Model'' (BSC 2001), use the wall heat fractions as outputted from the Ventilation Model to initialize their post-closure analyses. The Ventilation Model report was initially developed to analyze the effects of preclosure continuous ventilation in the Engineered Barrier System (EBS) emplacement drifts, and to provide heat removal data to support EBS design. Revision 00 of the Ventilation Model included documentation of the modeling results from the ANSYS-based heat transfer model. The purposes of Revision 01 of the Ventilation Model are: (1) To validate the conceptual model for preclosure ventilation of emplacement drifts and verify its numerical application in accordance with new procedural requirements as outlined in AP-SIII-10Q, Models (Section 7.0). (2) To satisfy technical issues posed in KTI agreement RDTME 3.14 (Reamer and Williams 2001a). Specifically to demonstrate, with respect to the ANSYS ventilation model, the adequacy of the discretization (Section 6.2.3.1), and the downstream applicability of the model results (i.e. wall heat fractions) to

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

    Energy Technology Data Exchange (ETDEWEB)

    Dudhia, J.; Guo, Y.R. [National Center for Atmospheric Research, Boulder, CO (United States)

    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.

  5. Modeling Documents with Event Model

    Directory of Open Access Journals (Sweden)

    Longhui Wang

    2015-08-01

    Full Text Available Currently deep learning has made great breakthroughs in visual and speech processing, mainly because it draws lessons from the hierarchical mode that brain deals with images and speech. In the field of NLP, a topic model is one of the important ways for modeling documents. Topic models are built on a generative model that clearly does not match the way humans write. In this paper, we propose Event Model, which is unsupervised and based on the language processing mechanism of neurolinguistics, to model documents. In Event Model, documents are descriptions of concrete or abstract events seen, heard, or sensed by people and words are objects in the events. Event Model has two stages: word learning and dimensionality reduction. Word learning is to learn semantics of words based on deep learning. Dimensionality reduction is the process that representing a document as a low dimensional vector by a linear mode that is completely different from topic models. Event Model achieves state-of-the-art results on document retrieval tasks.

  6. Modelling air quality impact of a biomass energy power plant in a mountain valley in Central Italy

    Science.gov (United States)

    Curci, Gabriele; Cinque, Giovanni; Tuccella, Paolo; Visconti, Guido; Verdecchia, Marco; Iarlori, Marco; Rizi, Vincenzo

    2012-12-01

    In this study, we investigate the potential impact on local air quality of a biomass power plant, which is planned for installation near L'Aquila, a city of 70,000 people located in a mountain valley in Central Italy. The assessment is carried out by applying a one year simulation with the CALPUFF model, following the recommendations of the U. S. Environmental Protection Agency. Meteorological input is produced with CALMET model, fed with both MM5 meteorological fields at 3 km resolution and wind observations from a surface weather station. We estimate small (<0.5 μg m-3) annual average increments to SO2, NO2 and PM10 ambient levels over the domain of interest, but significant (up to 50% for NO2) enhancements and several violations (up to 141 for NO2) of hourly limits for human protection within 1.5 km from the source. These results anticipate a larger negative effect on local air quality than those published by the building firm of the plant. We also suggest that a minimum distance of 5 km from the nearest residential area would represent a significant decrease of population exposure.

  7. Parameterization of gaseous dry deposition in atmospheric chemistry models: Sensitivity to aerodynamic resistance formulations under statically stable conditions

    Science.gov (United States)

    Toyota, Kenjiro; Dastoor, Ashu P.; Ryzhkov, Andrei

    2016-12-01

    Turbulence controls the vertical transfer of momentum, heat and trace constituents in the atmospheric boundary layer. In the lowest 10% of this layer lies the surface boundary layer (SBL) where the vertical fluxes of transferred quantities have been successfully parameterized using the Monin-Obukhov similarity theory in weather forecast, climate and atmospheric chemistry models. However, there is a large degree of empiricism in the stability-correction parameterizations used to formulate eddy diffusivity and aerodynamic resistance particularly under strongly stable ambient conditions. Although the influence of uncertainties in stability-correction parameterizations on eddy diffusivity is actively studied in boundary-layer meteorological modeling, its impact on dry deposition in atmospheric chemistry modeling is not well characterized. In this study, we address this gap by providing the mathematical basis for the relationship between the formulations of vertical surface flux used in meteorological and atmospheric chemistry modeling communities, and by examining the sensitivity of the modeled dry deposition velocities in statically stable SBL to the choice of stability-correction parameterizations used in three operational and/or research environmental models (GEM/GEM-MACH, ECMWF IFS and CMAQ-MM5). Aerodynamic resistances (ra) calculated by the three sets of parameterizations are notably different from each other and are also different from those calculated by a "z-less" scaling formulation under strongly stable conditions (the bulk Richardson number > 0.2). Furthermore, we show that many atmospheric chemistry models calculate ra using formulations which are inconsistent with the derivation of micro-meteorological parameters. Finally, practical implications of the differences in stability-correction algorithms are discussed for the computations of dry deposition velocities of SO2, O3 and reactive bromine compounds for specific cases of stable SBL.

  8. Model Selection for Geostatistical Models

    Energy Technology Data Exchange (ETDEWEB)

    Hoeting, Jennifer A.; Davis, Richard A.; Merton, Andrew A.; Thompson, Sandra E.

    2006-02-01

    We consider the problem of model selection for geospatial data. Spatial correlation is typically ignored in the selection of explanatory variables and this can influence model selection results. For example, the inclusion or exclusion of particular explanatory variables may not be apparent when spatial correlation is ignored. To address this problem, we consider the Akaike Information Criterion (AIC) as applied to a geostatistical model. We offer a heuristic derivation of the AIC in this context and provide simulation results that show that using AIC for a geostatistical model is superior to the often used approach of ignoring spatial correlation in the selection of explanatory variables. These ideas are further demonstrated via a model for lizard abundance. We also employ the principle of minimum description length (MDL) to variable selection for the geostatistical model. The effect of sampling design on the selection of explanatory covariates is also explored.

  9. Didactical modelling

    DEFF Research Database (Denmark)

    Højgaard, Tomas; Hansen, Rune

    2016-01-01

    The purpose of this paper is to introduce Didactical Modelling as a research methodology in mathematics education. We compare the methodology with other approaches and argue that Didactical Modelling has its own specificity. We discuss the methodological “why” and explain why we find it useful to...

  10. Didactical modelling

    OpenAIRE

    Højgaard, Tomas; Hansen, Rune

    2016-01-01

    The purpose of this paper is to introduce Didactical Modelling as a research methodology in mathematics education. We compare the methodology with other approaches and argue that Didactical Modelling has its own specificity. We discuss the methodological “why” and explain why we find it useful to construct this approach in mathematics education research.

  11. Animal models

    DEFF Research Database (Denmark)

    Gøtze, Jens Peter; Krentz, Andrew

    2014-01-01

    In this issue of Cardiovascular Endocrinology, we are proud to present a broad and dedicated spectrum of reviews on animal models in cardiovascular disease. The reviews cover most aspects of animal models in science from basic differences and similarities between small animals and the human...

  12. Martingale Model

    OpenAIRE

    Giandomenico, Rossano

    2006-01-01

    The model determines a stochastic continuous process as continuous limit of a stochastic discrete process so to show that the stochastic continuous process converges to the stochastic discrete process such that we can integrate it. Furthermore, the model determines the expected volatility and the expected mean so to show that the volatility and the mean are increasing function of the time.

  13. Dispersion Modeling.

    Science.gov (United States)

    Budiansky, Stephen

    1980-01-01

    This article discusses the need for more accurate and complete input data and field verification of the various models of air pollutant dispension. Consideration should be given to changing the form of air quality standards based on enhanced dispersion modeling techniques. (Author/RE)

  14. Education models

    NARCIS (Netherlands)

    Poortman, Sybilla; Sloep, Peter

    2006-01-01

    Educational models describes a case study on a complex learning object. Possibilities are investigated for using this learning object, which is based on a particular educational model, outside of its original context. Furthermore, this study provides advice that might lead to an increase in

  15. Battery Modeling

    NARCIS (Netherlands)

    Jongerden, M.R.; Haverkort, Boudewijn R.H.M.

    2008-01-01

    The use of mobile devices is often limited by the capacity of the employed batteries. The battery lifetime determines how long one can use a device. Battery modeling can help to predict, and possibly extend this lifetime. Many different battery models have been developed over the years. However,

  16. Linguistic models and linguistic modeling.

    Science.gov (United States)

    Pedryez, W; Vasilakos, A V

    1999-01-01

    The study is concerned with a linguistic approach to the design of a new category of fuzzy (granular) models. In contrast to numerically driven identification techniques, we concentrate on budding meaningful linguistic labels (granules) in the space of experimental data and forming the ensuing model as a web of associations between such granules. As such models are designed at the level of information granules and generate results in the same granular rather than pure numeric format, we refer to them as linguistic models. Furthermore, as there are no detailed numeric estimation procedures involved in the construction of the linguistic models carried out in this way, their design mode can be viewed as that of a rapid prototyping. The underlying algorithm used in the development of the models utilizes an augmented version of the clustering technique (context-based clustering) that is centered around a notion of linguistic contexts-a collection of fuzzy sets or fuzzy relations defined in the data space (more precisely a space of input variables). The detailed design algorithm is provided and contrasted with the standard modeling approaches commonly encountered in the literature. The usefulness of the linguistic mode of system modeling is discussed and illustrated with the aid of numeric studies including both synthetic data as well as some time series dealing with modeling traffic intensity over a broadband telecommunication network.

  17. OSPREY Model

    Energy Technology Data Exchange (ETDEWEB)

    Veronica J. Rutledge

    2013-01-01

    The absence of industrial scale nuclear fuel reprocessing in the U.S. has precluded the necessary driver for developing the advanced simulation capability now prevalent in so many other countries. Thus, it is essential to model complex series of unit operations to simulate, understand, and predict inherent transient behavior and feedback loops. A capability of accurately simulating the dynamic behavior of advanced fuel cycle separation processes will provide substantial cost savings and many technical benefits. The specific fuel cycle separation process discussed in this report is the off-gas treatment system. The off-gas separation consists of a series of scrubbers and adsorption beds to capture constituents of interest. Dynamic models are being developed to simulate each unit operation involved so each unit operation can be used as a stand-alone model and in series with multiple others. Currently, an adsorption model has been developed within Multi-physics Object Oriented Simulation Environment (MOOSE) developed at the Idaho National Laboratory (INL). Off-gas Separation and REcoverY (OSPREY) models the adsorption of off-gas constituents for dispersed plug flow in a packed bed under non-isothermal and non-isobaric conditions. Inputs to the model include gas, sorbent, and column properties, equilibrium and kinetic data, and inlet conditions. The simulation outputs component concentrations along the column length as a function of time from which breakthrough data is obtained. The breakthrough data can be used to determine bed capacity, which in turn can be used to size columns. It also outputs temperature along the column length as a function of time and pressure drop along the column length. Experimental data and parameters were input into the adsorption model to develop models specific for krypton adsorption. The same can be done for iodine, xenon, and tritium. The model will be validated with experimental breakthrough curves. Customers will be given access to

  18. Nonlinear mathematical modeling and sensitivity analysis of hydraulic drive unit

    Science.gov (United States)

    Kong, Xiangdong; Yu, Bin; Quan, Lingxiao; Ba, Kaixian; Wu, Liujie

    2015-09-01

    The previous sensitivity analysis researches are not accurate enough and also have the limited reference value, because those mathematical models are relatively simple and the change of the load and the initial displacement changes of the piston are ignored, even experiment verification is not conducted. Therefore, in view of deficiencies above, a nonlinear mathematical model is established in this paper, including dynamic characteristics of servo valve, nonlinear characteristics of pressure-flow, initial displacement of servo cylinder piston and friction nonlinearity. The transfer function block diagram is built for the hydraulic drive unit closed loop position control, as well as the state equations. Through deriving the time-varying coefficient items matrix and time-varying free items matrix of sensitivity equations respectively, the expression of sensitivity equations based on the nonlinear mathematical model are obtained. According to structure parameters of hydraulic drive unit, working parameters, fluid transmission characteristics and measured friction-velocity curves, the simulation analysis of hydraulic drive unit is completed on the MATLAB/Simulink simulation platform with the displacement step 2 mm, 5 mm and 10 mm, respectively. The simulation results indicate that the developed nonlinear mathematical model is sufficient by comparing the characteristic curves of experimental step response and simulation step response under different constant load. Then, the sensitivity function time-history curves of seventeen parameters are obtained, basing on each state vector time-history curve of step response characteristic. The maximum value of displacement variation percentage and the sum of displacement variation absolute values in the sampling time are both taken as sensitivity indexes. The sensitivity indexes values above are calculated and shown visually in histograms under different working conditions, and change rules are analyzed. Then the sensitivity

  19. Evaluating the impacts of cumulus, land surface and ocean surface schemes on summertime rainfall simulations over East-to-southeast Asia and the western north Pacific by RegCM4

    Science.gov (United States)

    Li, Yu-Bin; Tam, Chi-Yung; Huang, Wan-Ru; Cheung, Kevin K. W.; Gao, Zhiqiu

    2016-04-01

    This study evaluates the sensitivity of summertime rainfall simulations over East-to-southeast Asia and the western north Pacific in the regional climate model version 4 (RegCM4) to cumulus (including Grell with Arakawa-Schubert type closure, Grell with Fritsch-Chappell type closure, and Emanuel), land surface (Biosphere-atmosphere transfer scheme or BATS, and the community land model or CLM) and ocean surface (referred to as Zeng1, Zeng2 and BATS1e in the model) schemes by running the model with different combinations of these parameterization packages. For each of these experiments, ensemble integration of the model was carried out in the extended boreal summer of May-October from 1998 to 2007. The simulated spatial distribution, intensity and inter-annual variation of the precipitation, latent heat flux, position of the subtropical high and tropical cyclone genesis patterns from these numerical experiments were analyzed. Examinations show that the combination of Emanuel, CLM and Zeng2 (E-C-Z2) yields the best overall results, consistent with the fact that physical mechanisms considered in E-C-Z2 tend to be more comprehensive in comparison with the others. Additionally, the rainfall quantity is found very sensitive to sea surface roughness length, and the reduction of the roughness length constant (from 2 × 10-4 to 5 × 10-5 m) in our modified BATS1e mitigates the drastic overestimation of latent heat flux and rainfall, and is therefore preferable to the default value for simulations in the western north Pacific region in RegCM4.

  20. Testing the ability of RIEMS2.0 (Regional Integrated Environment Modeling System) on regional climate simulation in East Asia

    Science.gov (United States)

    Zhao, D.; Fu, C.; Yan, X.

    2010-12-01

    RIEMS1.0 (Regional Integrated Environmental Modeling System version 1.0) was developed by researchers from the START (Global change System for Analysis, Research, and Training) Regional Center for Temperate East Asia, IAP/CAS in 1998. The model was built on the thermodynamic frame of PSU/NCAR MM5V2, into which a land surface scheme (BATS1e) and radiative transfer scheme (the revised CCM3) are integrated. The model has been widely used in regional climate studies in the East Asia monsoon system and expresses excellent performance from RMIP (Regional Climate Model Inter-comparison Project). RIEMS2.0 is now being developed starting from RIEMS1.0 by the Key Laboratory of Regional Climate Environment Research for Temperate East Asia, IAP/CAS, and Nanjing University. The new version is built on the thermodynamic framework of nonhydrostatic approximation from MM5V3 with the same land surface model and radiation scheme as RIEMS1.0. To make it an integrated modeling system, the Princeton ocean mode (POM), Atmosphere-Vegetation interaction model (AVIM) and a chemical model are now being integrated. In order to test RIEMS2.0’s ability to simulate short-term climate, we perform ensemble simulations with different physics process schemes. The model will be used to perform ensemble simulations on two continuous extreme climate events, which is serve drought with high temperature in north China in the summer (June, July and August) of 1997 and serve flood in the Yangtze River valley in the summer of 1998. The results show that RIEMS2.0 can reproduce the spatial distribution of the precipitation and SAT from two continuous extreme climate events in the summer of 1997/1998, and disclose sub-regional characteristics. Though difference can be found among ensemble members, ensembles can decrease the model’s uncertainty and improve the simulation decision in a certain degree. In order to test RIEMS2.0’s ability to simulate long-term climate and climate change, we compare

  1. Modeling spatial patterns of wildfire susceptibility in southern California: Applications of MODIS remote sensing data and mesoscale numerical weather models

    Science.gov (United States)

    Schneider, Philipp

    This dissertation investigates the potential of Moderate Resolution Imaging Spectroradiometer (MODIS) imagery and mesoscale numerical weather models for mapping wildfire susceptibility in general and for improving the Fire Potential Index (FPI) in southern California in particular. The dissertation explores the use of the Visible Atmospherically Resistant Index (VARI) from MODIS data for mapping relative greenness (RG) of vegetation and subsequently for computing the FPI. VARI-based RG was validated against in situ observations of live fuel moisture. The results indicate that VARI is superior to the previously used Normalized Difference Vegetation Index (NDVI) for computing RG. FPI computed using VARI-based RG was found to outperform the traditional FPI when validated against historical fire detections using logistic regression. The study further investigates the potential of using Multiple Endmember Spectral Mixture Analysis (MESMA) on MODIS data for estimating live and dead fractions of vegetation. MESMA fractions were compared against in situ measurements and fractions derived from data of a high-resolution, hyperspectral sensor. The results show that live and dead fractions obtained from MODIS using MESMA are well correlated with the reference data. Further, FPI computed using MESMA-based green vegetation fraction in lieu of RG was validated against historical fire occurrence data. MESMA-based FPI performs at a comparable level to the traditional NDVI-based FPI, but can do so using a single MODIS image rather than an extensive remote sensing time series as required for the RG approach. Finally this dissertation explores the potential of integrating gridded wind speed data obtained from the MM5 mesoscale numerical weather model in the FPI. A new fire susceptibility index, the Wind-Adjusted Fire Potential Index (WAFPI), was introduced. It modifies the FPI algorithm by integrating normalized wind speed. Validating WAFPI against historical wildfire events using

  2. Model hydrographs

    Science.gov (United States)

    Mitchell, W.D.

    1972-01-01

    Model hydrographs are composed of pairs of dimensionless ratios, arrayed in tabular form, which, when modified by the appropriate values of rainfall exceed and by the time and areal characteristics of the drainage basin, satisfactorily represent the flood hydrograph for the basin. Model bydrographs are developed from a dimensionless translation hydrograph, having a time base of T hours and appropriately modified for storm duration by routing through reservoir storage, S=kOx. Models fall into two distinct classes: (1) those for which the value of x is unity and which have all the characteristics of true unit hydrographs and (2) those for which the value of x is other than unity and to which the unit-hydrograph principles of proportionality and superposition do not apply. Twenty-six families of linear models and eight families of nonlinear models in tabular form from the principal subject of this report. Supplemental discussions describe the development of the models and illustrate their application. Other sections of the report, supplemental to the tables, describe methods of determining the hydrograph characteristics, T, k, and x, both from observed hydrograph and from the physical characteristics of the drainage basin. Five illustrative examples of use show that the models, when properly converted to incorporate actual rainfall excess and the time and areal characteristics of the drainage basins, do indeed satisfactorily represent the observed flood hydrographs for the basins.

  3. Stereometric Modelling

    Science.gov (United States)

    Grimaldi, P.

    2012-07-01

    These mandatory guidelines are provided for preparation of papers accepted for publication in the series of Volumes of The The stereometric modelling means modelling achieved with : - the use of a pair of virtual cameras, with parallel axes and positioned at a mutual distance average of 1/10 of the distance camera-object (in practice the realization and use of a stereometric camera in the modeling program); - the shot visualization in two distinct windows - the stereoscopic viewing of the shot while modelling. Since the definition of "3D vision" is inaccurately referred to as the simple perspective of an object, it is required to add the word stereo so that "3D stereo vision " shall stand for "three-dimensional view" and ,therefore, measure the width, height and depth of the surveyed image. Thanks to the development of a stereo metric model , either real or virtual, through the "materialization", either real or virtual, of the optical-stereo metric model made visible with a stereoscope. It is feasible a continuous on line updating of the cultural heritage with the help of photogrammetry and stereometric modelling. The catalogue of the Architectonic Photogrammetry Laboratory of Politecnico di Bari is available on line at: http://rappresentazione.stereofot.it:591/StereoFot/FMPro?-db=StereoFot.fp5&-lay=Scheda&-format=cerca.htm&-view

  4. Modeling complexes of modeled proteins.

    Science.gov (United States)

    Anishchenko, Ivan; Kundrotas, Petras J; Vakser, Ilya A

    2017-03-01

    Structural characterization of proteins is essential for understanding life processes at the molecular level. However, only a fraction of known proteins have experimentally determined structures. This fraction is even smaller for protein-protein complexes. Thus, structural modeling of protein-protein interactions (docking) primarily has to rely on modeled structures of the individual proteins, which typically are less accurate than the experimentally determined ones. Such "double" modeling is the Grand Challenge of structural reconstruction of the interactome. Yet it remains so far largely untested in a systematic way. We present a comprehensive validation of template-based and free docking on a set of 165 complexes, where each protein model has six levels of structural accuracy, from 1 to 6 Å C(α) RMSD. Many template-based docking predictions fall into acceptable quality category, according to the CAPRI criteria, even for highly inaccurate proteins (5-6 Å RMSD), although the number of such models (and, consequently, the docking success rate) drops significantly for models with RMSD > 4 Å. The results show that the existing docking methodologies can be successfully applied to protein models with a broad range of structural accuracy, and the template-based docking is much less sensitive to inaccuracies of protein models than the free docking. Proteins 2017; 85:470-478. © 2016 Wiley Periodicals, Inc. © 2016 Wiley Periodicals, Inc.

  5. A Model for Math Modeling

    Science.gov (United States)

    Lin, Tony; Erfan, Sasan

    2016-01-01

    Mathematical modeling is an open-ended research subject where no definite answers exist for any problem. Math modeling enables thinking outside the box to connect different fields of studies together including statistics, algebra, calculus, matrices, programming and scientific writing. As an integral part of society, it is the foundation for many…

  6. Modelling survival

    DEFF Research Database (Denmark)

    Ashauer, Roman; Albert, Carlo; Augustine, Starrlight

    2016-01-01

    The General Unified Threshold model for Survival (GUTS) integrates previously published toxicokinetic-toxicodynamic models and estimates survival with explicitly defined assumptions. Importantly, GUTS accounts for time-variable exposure to the stressor. We performed three studies to test...... the ability of GUTS to predict survival of aquatic organisms across different pesticide exposure patterns, time scales and species. Firstly, using synthetic data, we identified experimental data requirements which allow for the estimation of all parameters of the GUTS proper model. Secondly, we assessed how...

  7. Modelling Constructs

    DEFF Research Database (Denmark)

    Kindler, Ekkart

    2009-01-01

    There are many different notations and formalisms for modelling business processes and workflows. These notations and formalisms have been introduced with different purposes and objectives. Later, influenced by other notations, comparisons with other tools, or by standardization efforts, these no...

  8. Linear Models

    CERN Document Server

    Searle, Shayle R

    2012-01-01

    This 1971 classic on linear models is once again available--as a Wiley Classics Library Edition. It features material that can be understood by any statistician who understands matrix algebra and basic statistical methods.

  9. Modeling Arcs

    CERN Document Server

    Insepov, Zeke; Veitzer, Seth; Mahalingam, Sudhakar

    2011-01-01

    Although vacuum arcs were first identified over 110 years ago, they are not yet well understood. We have since developed a model of breakdown and gradient limits that tries to explain, in a self-consistent way: arc triggering, plasma initiation, plasma evolution, surface damage and gra- dient limits. We use simple PIC codes for modeling plasmas, molecular dynamics for modeling surface breakdown, and surface damage, and mesoscale surface thermodynamics and finite element electrostatic codes for to evaluate surface properties. Since any given experiment seems to have more variables than data points, we have tried to consider a wide variety of arcing (rf structures, e beam welding, laser ablation, etc.) to help constrain the problem, and concentrate on common mechanisms. While the mechanisms can be comparatively simple, modeling can be challenging.

  10. Paleoclimate Modeling

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Computer simulations of past climate. Variables provided as model output are described by parameter keyword. In some cases the parameter keywords are a subset of all...

  11. Anchor Modeling

    Science.gov (United States)

    Regardt, Olle; Rönnbäck, Lars; Bergholtz, Maria; Johannesson, Paul; Wohed, Petia

    Maintaining and evolving data warehouses is a complex, error prone, and time consuming activity. The main reason for this state of affairs is that the environment of a data warehouse is in constant change, while the warehouse itself needs to provide a stable and consistent interface to information spanning extended periods of time. In this paper, we propose a modeling technique for data warehousing, called anchor modeling, that offers non-destructive extensibility mechanisms, thereby enabling robust and flexible management of changes in source systems. A key benefit of anchor modeling is that changes in a data warehouse environment only require extensions, not modifications, to the data warehouse. This ensures that existing data warehouse applications will remain unaffected by the evolution of the data warehouse, i.e. existing views and functions will not have to be modified as a result of changes in the warehouse model.

  12. Model theory

    CERN Document Server

    Hodges, Wilfrid

    1993-01-01

    An up-to-date and integrated introduction to model theory, designed to be used for graduate courses (for students who are familiar with first-order logic), and as a reference for more experienced logicians and mathematicians.

  13. Accelerated life models modeling and statistical analysis

    CERN Document Server

    Bagdonavicius, Vilijandas

    2001-01-01

    Failure Time DistributionsIntroductionParametric Classes of Failure Time DistributionsAccelerated Life ModelsIntroductionGeneralized Sedyakin's ModelAccelerated Failure Time ModelProportional Hazards ModelGeneralized Proportional Hazards ModelsGeneralized Additive and Additive-Multiplicative Hazards ModelsChanging Shape and Scale ModelsGeneralizationsModels Including Switch-Up and Cycling EffectsHeredity HypothesisSummaryAccelerated Degradation ModelsIntroductionDegradation ModelsModeling the Influence of Explanatory Varia

  14. Three-dimensional Simulations of the Mean Air Transport During the 1997 Forest Fires in Kalimantan, Indonesia Using a Mesoscale Numerical Model

    Science.gov (United States)

    Roswintiarti, O.; Raman, S.

    - 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) Mesoscale Model (MM5) is used to simulate three-dimensional winds at 6-hourly intervals. A nonhydrostatic version of the model is run using two nested 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 model.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.

  15. Air quality over Europe: modeling gaseous and particulate pollutants and the effect of precursor emissions

    Directory of Open Access Journals (Sweden)

    E. Tagaris

    2013-03-01

    Full Text Available Air quality over Europe using Models-3 (i.e. CMAQ, MM5, SMOKE modeling system is performed for winter (i.e. January, 2006 and summer (i.e. July, 2006 months with the 2006 TNO gridded anthropogenic emissions database. Higher ozone concentrations are illustrated in southern Europe while higher NO2 concentrations are simulated over western Europe. Elevated SO2 concentrations are simulated over eastern Europe while elevated PM2.5 levels are simulated over eastern and western Europe. Results suggest that NO2 and PM2.5 are underpredicted, SO2 is overpredicted while Max8hrO3 is overpredicted for low concentrations and is underpredicted for the higher ones. Speciated PM2.5 components suggest that NO3 is dominant during winter in western Europe and in a few eastern countries due to the high NO2 concentrations. During summer NO3 is dominant only in regions with elevated NH3 emissions. For the rest of the domain SO4 is dominant. Low OC concentrations are simulated mainly due to the uncertain representation of SOA formation. The difference between observed and predicted concentrations for each country is assessed for the gaseous and particulate pollutants. The simultaneous precursor emissions change applying scaling factors on NOx, SO2 and PM2.5 emissions based on the observed/predicted ratio for each country seems to statistically enhance model performance (in gaseous pollutants the improvement in root mean square is up to 5.6 ppbV, in the index of agreement is up to 0.3 and in the mean absolute error is up to 4.2 ppbV while the related values in PM2.5 are 4.5 μg m−3, 0.2 and 3.5 μg m−3, respectively.

  16. Do stroke models model stroke?

    Directory of Open Access Journals (Sweden)

    Philipp Mergenthaler

    2012-11-01

    Full Text Available Stroke is one of the leading causes of death worldwide and the biggest reason for long-term disability. Basic research has formed the modern understanding of stroke pathophysiology, and has revealed important molecular, cellular and systemic mechanisms. However, despite decades of research, most translational stroke trials that aim to introduce basic research findings into clinical treatment strategies – most notably in the field of neuroprotection – have failed. Among other obstacles, poor methodological and statistical standards, negative publication bias, and incomplete preclinical testing have been proposed as ‘translational roadblocks’. In this article, we introduce the models commonly used in preclinical stroke research, discuss some of the causes of failed translational success and review potential remedies. We further introduce the concept of modeling ‘care’ of stroke patients, because current preclinical research models the disorder but does not model care or state-of-the-art clinical testing. Stringent statistical methods and controlled preclinical trials have been suggested to counteract weaknesses in preclinical research. We conclude that preclinical stroke research requires (1 appropriate modeling of the disorder, (2 appropriate modeling of the care of stroke patients and (3 an approach to preclinical testing that is similar to clinical testing, including Phase 3 randomized controlled preclinical trials as necessary additional steps before new therapies enter clinical testing.

  17. Persistent Modelling

    DEFF Research Database (Denmark)

    2012-01-01

    The relationship between representation and the represented is examined here through the notion of persistent modelling. This notion is not novel to the activity of architectural design if it is considered as describing a continued active and iterative engagement with design concerns – an evident...... characteristic of architectural practice. But the persistence in persistent modelling can also be understood to apply in other ways, reflecting and anticipating extended roles for representation. This book identifies three principle areas in which these extensions are becoming apparent within contemporary....... It also provides critical insight into the use of contemporary modelling tools and methods, together with an examination of the implications their use has within the territories of architectural design, realisation and experience....

  18. Mathematical modeling

    CERN Document Server

    Eck, Christof; Knabner, Peter

    2017-01-01

    Mathematical models are the decisive tool to explain and predict phenomena in the natural and engineering sciences. With this book readers will learn to derive mathematical models which help to understand real world phenomena. At the same time a wealth of important examples for the abstract concepts treated in the curriculum of mathematics degrees are given. An essential feature of this book is that mathematical structures are used as an ordering principle and not the fields of application. Methods from linear algebra, analysis and the theory of ordinary and partial differential equations are thoroughly introduced and applied in the modeling process. Examples of applications in the fields electrical networks, chemical reaction dynamics, population dynamics, fluid dynamics, elasticity theory and crystal growth are treated comprehensively.

  19. Inflatable Models

    Institute of Scientific and Technical Information of China (English)

    Ling Li; Vasily Volkov

    2006-01-01

    A physically-based model is presented for the simulation of a new type of deformable objects-inflatable objects, such as shaped balloons, which consist of pressurized air enclosed by an elastic surface. These objects have properties inherent in both 3D and 2D elastic bodies, as they demonstrate the behaviour of 3D shapes using 2D formulations. As there is no internal structure in them, their behaviour is substantially different from the behaviour of deformable solid objects. We use one of the few available models for deformable surfaces, and enhance it to include the forces of internal and external pressure. These pressure forces may also incorporate buoyancy forces, to allow objects filled with a low density gas to float in denser media. The obtained models demonstrate rich dynamic behaviour, such as bouncing, floating, deflation and inflation.

  20. Lens Model

    DEFF Research Database (Denmark)

    Nash, Ulrik William

    2014-01-01

    Firms consist of people who make decisions to achieve goals. How do these people develop the expectations which underpin the choices they make? The lens model provides one answer to this question. It was developed by cognitive psychologist Egon Brunswik (1952) to illustrate his theory of probabil......Firms consist of people who make decisions to achieve goals. How do these people develop the expectations which underpin the choices they make? The lens model provides one answer to this question. It was developed by cognitive psychologist Egon Brunswik (1952) to illustrate his theory...... of probabilistic functionalism, and concerns the environment and the mind, and adaptation by the latter to the former. This entry is about the lens model, and probabilistic functionalism more broadly. Focus will mostly be on firms and their employees, but, to fully appreciate the scope, we have to keep in mind...

  1. Lens Model

    DEFF Research Database (Denmark)

    Nash, Ulrik William

    2014-01-01

    Firms consist of people who make decisions to achieve goals. How do these people develop the expectations which underpin the choices they make? The lens model provides one answer to this question. It was developed by cognitive psychologist Egon Brunswik (1952) to illustrate his theory of probabil......Firms consist of people who make decisions to achieve goals. How do these people develop the expectations which underpin the choices they make? The lens model provides one answer to this question. It was developed by cognitive psychologist Egon Brunswik (1952) to illustrate his theory...

  2. Molecular modeling

    Directory of Open Access Journals (Sweden)

    Aarti Sharma

    2009-01-01

    Full Text Available The use of computational chemistry in the development of novel pharmaceuticals is becoming an increasingly important tool. In the past, drugs were simply screened for effectiveness. The recent advances in computing power and the exponential growth of the knowledge of protein structures have made it possible for organic compounds to be tailored to decrease the harmful side effects and increase the potency. This article provides a detailed description of the techniques employed in molecular modeling. Molecular modeling is a rapidly developing discipline, and has been supported by the dramatic improvements in computer hardware and software in recent years.

  3. Smashnova Model

    CERN Document Server

    Sivaram, C

    2007-01-01

    An alternate model for gamma ray bursts is suggested. For a white dwarf (WD) and neutron star (NS) very close binary system, the WD (close to Mch) can detonate due to tidal heating, leading to a SN. Material falling on to the NS at relativistic velocities can cause its collapse to a magnetar or quark star or black hole leading to a GRB. As the material smashes on to the NS, it is dubbed the Smashnova model. Here the SN is followed by a GRB. NS impacting a RG (or RSG) (like in Thorne-Zytkow objects) can also cause a SN outburst followed by a GRB. Other variations are explored.

  4. Modelling language

    CERN Document Server

    Cardey, Sylviane

    2013-01-01

    In response to the need for reliable results from natural language processing, this book presents an original way of decomposing a language(s) in a microscopic manner by means of intra/inter‑language norms and divergences, going progressively from languages as systems to the linguistic, mathematical and computational models, which being based on a constructive approach are inherently traceable. Languages are described with their elements aggregating or repelling each other to form viable interrelated micro‑systems. The abstract model, which contrary to the current state of the art works in int

  5. Building Models and Building Modelling

    DEFF Research Database (Denmark)

    Jørgensen, Kaj Asbjørn; Skauge, Jørn

    I rapportens indledende kapitel beskrives de primære begreber vedrørende bygningsmodeller og nogle fundamentale forhold vedrørende computerbaseret modulering bliver opstillet. Desuden bliver forskellen mellem tegneprogrammer og bygnings­model­lerings­programmer beskrevet. Vigtige aspekter om......­lering og bygningsmodeller. Det bliver understreget at modellering bør udføres på flere abstraktions­niveauer og i to dimensioner i den såkaldte modelleringsmatrix. Ud fra dette identificeres de primære faser af bygningsmodel­lering. Dernæst beskrives de basale karakteristika for bygningsmodeller. Heri...... inkluderes en præcisering af begreberne objektorienteret software og objektorienteret modeller. Det bliver fremhævet at begrebet objektbaseret modellering giver en tilstrækkelig og bedre forståelse. Endelig beskrives forestillingen om den ideale bygningsmodel som værende én samlet model, der anvendes gennem...

  6. Zeebrugge Model

    DEFF Research Database (Denmark)

    Jensen, Morten S.; Frigaard, Peter

    In the following, results from model tests with Zeebrugge breakwater are presented. The objective with these tests is partly to investigate the influence on wave run-up due to a changing waterlevel during a storm. Finally, the influence on wave run-up due to an introduced longshore current...

  7. Why Model?

    Directory of Open Access Journals (Sweden)

    Olaf eWolkenhauer

    2014-01-01

    Full Text Available Next generation sequencing technologies are bringing about a renaissance of mining approaches. A comprehensive picture of the genetic landscape of an individual patient will be useful, for example, to identify groups of patients that do or do not respond to certain therapies. The high expectations may however not be satisfied if the number of patient groups with similar characteristics is going to be very large. I therefore doubt that mining sequence data will give us an understanding of why and when therapies work. For understanding the mechanisms underlying diseases, an alternative approach is to model small networks in quantitative mechanistic detail, to elucidate the role of gene and proteins in dynamically changing the functioning of cells. Here an obvious critique is that these models consider too few components, compared to what might be relevant for any particular cell function. I show here that mining approaches and dynamical systems theory are two ends of a spectrum of methodologies to choose from. Drawing upon personal experience in numerous interdisciplinary collaborations, I provide guidance on how to model by discussing the question Why model?

  8. Why model?

    Science.gov (United States)

    Wolkenhauer, Olaf

    2014-01-01

    Next generation sequencing technologies are bringing about a renaissance of mining approaches. A comprehensive picture of the genetic landscape of an individual patient will be useful, for example, to identify groups of patients that do or do not respond to certain therapies. The high expectations may however not be satisfied if the number of patient groups with similar characteristics is going to be very large. I therefore doubt that mining sequence data will give us an understanding of why and when therapies work. For understanding the mechanisms underlying diseases, an alternative approach is to model small networks in quantitative mechanistic detail, to elucidate the role of gene and proteins in dynamically changing the functioning of cells. Here an obvious critique is that these models consider too few components, compared to what might be relevant for any particular cell function. I show here that mining approaches and dynamical systems theory are two ends of a spectrum of methodologies to choose from. Drawing upon personal experience in numerous interdisciplinary collaborations, I provide guidance on how to model by discussing the question "Why model?"

  9. Model CAPM

    OpenAIRE

    Burianová, Eva

    2008-01-01

    Cílem první části této bakalářské práce je - pomocí analýzy výchozích textů - teoretické shrnutí ekonomických modelů a teorií, na kterých model CAPM stojí: Markowitzův model teorie portfolia (analýza maximalizace očekávaného užitku a na něm založený model výběru optimálního portfolia), Tobina (rozšíření Markowitzova modelu ? rozdělení výběru optimálního portfolia do dvou fází; nejprve určení optimální kombinace rizikových instrumentů a následná alokace dostupného kapitálu mezi tuto optimální ...

  10. Transport modeling

    Institute of Scientific and Technical Information of China (English)

    R.E. Waltz

    2007-01-01

    @@ There has been remarkable progress during the past decade in understanding and modeling turbulent transport in tokamaks. With some exceptions the progress is derived from the huge increases in computational power and the ability to simulate tokamak turbulence with ever more fundamental and physically realistic dynamical equations, e.g.

  11. Painting models

    Science.gov (United States)

    Baart, F.; Donchyts, G.; van Dam, A.; Plieger, M.

    2015-12-01

    The emergence of interactive art has blurred the line between electronic, computer graphics and art. Here we apply this art form to numerical models. Here we show how the transformation of a numerical model into an interactive painting can both provide insights and solve real world problems. The cases that are used as an example include forensic reconstructions, dredging optimization, barrier design. The system can be fed using any source of time varying vector fields, such as hydrodynamic models. The cases used here, the Indian Ocean (HYCOM), the Wadden Sea (Delft3D Curvilinear), San Francisco Bay (3Di subgrid and Delft3D Flexible Mesh), show that the method used is suitable for different time and spatial scales. High resolution numerical models become interactive paintings by exchanging their velocity fields with a high resolution (>=1M cells) image based flow visualization that runs in a html5 compatible web browser. The image based flow visualization combines three images into a new image: the current image, a drawing, and a uv + mask field. The advection scheme that computes the resultant image is executed in the graphics card using WebGL, allowing for 1M grid cells at 60Hz performance on mediocre graphic cards. The software is provided as open source software. By using different sources for a drawing one can gain insight into several aspects of the velocity fields. These aspects include not only the commonly represented magnitude and direction, but also divergence, topology and turbulence .

  12. Modeling Muscles

    Science.gov (United States)

    Goodwyn, Lauren; Salm, Sarah

    2007-01-01

    Teaching the anatomy of the muscle system to high school students can be challenging. Students often learn about muscle anatomy by memorizing information from textbooks or by observing plastic, inflexible models. Although these mediums help students learn about muscle placement, the mediums do not facilitate understanding regarding integration of…

  13. Entrepreneurship Models.

    Science.gov (United States)

    Finger Lakes Regional Education Center for Economic Development, Mount Morris, NY.

    This guide describes seven model programs that were developed by the Finger Lakes Regional Center for Economic Development (New York) to meet the training needs of female and minority entrepreneurs to help their businesses survive and grow and to assist disabled and dislocated workers and youth in beginning small businesses. The first three models…

  14. Quality modelling

    NARCIS (Netherlands)

    Tijskens, L.M.M.

    2003-01-01

    For modelling product behaviour, with respect to quality for users and consumers, its essential to have at least a fundamental notion what quality really is, and which product properties determine the quality assigned by the consumer to a product. In other words: what is allowed and what is to be

  15. Criticality Model

    Energy Technology Data Exchange (ETDEWEB)

    A. Alsaed

    2004-09-14

    The ''Disposal Criticality Analysis Methodology Topical Report'' (YMP 2003) presents the methodology for evaluating potential criticality situations in the monitored geologic repository. As stated in the referenced Topical Report, the detailed methodology for performing the disposal criticality analyses will be documented in model reports. Many of the models developed in support of the Topical Report differ from the definition of models as given in the Office of Civilian Radioactive Waste Management procedure AP-SIII.10Q, ''Models'', in that they are procedural, rather than mathematical. These model reports document the detailed methodology necessary to implement the approach presented in the Disposal Criticality Analysis Methodology Topical Report and provide calculations utilizing the methodology. Thus, the governing procedure for this type of report is AP-3.12Q, ''Design Calculations and Analyses''. The ''Criticality Model'' is of this latter type, providing a process evaluating the criticality potential of in-package and external configurations. The purpose of this analysis is to layout the process for calculating the criticality potential for various in-package and external configurations and to calculate lower-bound tolerance limit (LBTL) values and determine range of applicability (ROA) parameters. The LBTL calculations and the ROA determinations are performed using selected benchmark experiments that are applicable to various waste forms and various in-package and external configurations. The waste forms considered in this calculation are pressurized water reactor (PWR), boiling water reactor (BWR), Fast Flux Test Facility (FFTF), Training Research Isotope General Atomic (TRIGA), Enrico Fermi, Shippingport pressurized water reactor, Shippingport light water breeder reactor (LWBR), N-Reactor, Melt and Dilute, and Fort Saint Vrain Reactor spent nuclear fuel (SNF). The scope of

  16. Estimation of Secondary Compounds Concentrations Contributed by Biogenic VOC With Chemical Transport Model in the Central Area of Japan

    Science.gov (United States)

    Yamamoto, K.; Kanemaru, A.; Okumura, M.; Tohno, S.

    2008-12-01

    Biogenic VOC (BVOC) has comparably large contribution to generation of secondary air pollutants, such as photochemical oxidant or urban aerosol. In this study a BVOC emission inventory in the Kansai area, which is located in the central part of Japan, based on the field observation was developed. Some validations of the inventory were conducted by estimating the concentration distribution of oxidants with this developed and an existing BVOC emission inventory in Kansai area by meteorological model MM5 and atmospheric chemical transport model CMAQ. In the development of BVOC emission, the vegetation map by the Biodiversity Center of Japan which had been arranged as basic information on natural environmental preservation in a regional standard mesh (the third mesh) in 1999 was used. In this study isoprene and the mono-terpene were taken up as BVOC. Quercus crispula and Quercus serrata were selected as the source of isoprene, and Cryptomeria japonica, Chamaecyparis obtuse, Quercus phillyraeoides, Pinus densiflora, and Pinus thunbergii were selected as sources of mono-terpene. The parameter of the basic emission rate included in the model was decided by arranging the result of the observation in Kansai Research Center of Forestry and Forest Products Research Institute in each season. This emission flux from each species were calculated by G93 model by Guenther et al. and meteorological fields for the model, such as temperatures and sunlight intensities, were renewed hour by hour, therefore, this emission inventory has a high time resolution according to the season and time. In calculating meteorological fields, meteorological model MM5 Ver.3.7 was conducted in Japanese standard mesh in the selected five days of April, July, and October in 2004, and January 2005 respectively, and taking out the result of wind velocities and temperatures for substituting to the G93 model. Then atmospheric chemical transport model CMAQ Ver.4.6 with the emission inventories and

  17. Information Model for Product Modeling

    Institute of Scientific and Technical Information of China (English)

    焦国方; 刘慎权

    1992-01-01

    The Key problems in product modeling for integrated CAD ∥CAM systems are the information structures and representations of products.They are taking more and more important roles in engineering applications.With the investigation on engineering product information and from the viewpoint of industrial process,in this paper,the information models are proposed and the definitions of the framework of product information are given.And then,the integration and the consistence of product information are discussed by introucing the entity and its instance.As a summary,the information structures described in this paper have many advantage and natures helpful in engineering design.

  18. APPLYING SPATIAL ANALYSIS TOOLS IN PUBLIC HEALTH: THE USE OF AERMOD IN MODELING THE EMISSION DISPERSION OF SO2 AND NO2 TO IDENTIFY AREA EXPOSED TO HEALTH RISKS

    Directory of Open Access Journals (Sweden)

    Erwin Azizi Jayadipraja

    2016-03-01

    Full Text Available Background: The cement industry is one of the main contributors of pollutant gasses in the environment through stack emissions. Aim: This study aims to model the dispersion of SO2 and NO2 gasses and to determine the area of the dispersion by American Meteorological Society – Environmental Protection Agency Regulation Model or AERMOD has been utilized by PT. Semen Tonasa (Tonasa Cement, Ltd.. Methods: Meteorological data from AERMENT was collected from reanalysis of MM5 data. While topographical data was extracted from SRTM30 satellite data. The model was carried out for a year, to cover both the dry and rainy season. Results: The result of the modeling showed that the peak value of the concentration of SO2 and NO2 pollutants for one hour are 135 μg/m3 and 160 μg/m3 respectively (quality standards of SO2 and NO2 are 900 μg/Nm3 and 400 μg/Nm3. The area of dispersion tends to be in the eastern area, such as District Minasatene (Sub-district Bontoa, Kalabbirang, Minasatene dan Biraeng, District Bungoro (Sub-district Biringere, Sapanang, Mangilu, Bulu Tellue and District Labakkang (Sub-district Taraweang.

  19. The Santa Barbara Channel - Santa Maria Basin Study: Wind Measurements and Modeling Resolving Coastal Mesoscale Meteorology

    Science.gov (United States)

    Dorman, C. E.; Koracin, D.

    2002-12-01

    The importance of winds in driving the coastal ocean has long been recognized. Pre-World War II literature links wind stress and wind stress curl to coastal ocean responses. Nevertheless, direct measurements plausibly representative of a coastal area are few. Multiple observations on the scale of the simplest mesoscale atmospheric structure, such as the cross-coast variation along a linear coast, are even less frequent. The only wind measurements that we are aware of in a complicated coastal area backed by higher topography are in the MMS sponsored, Santa Barbara Channel/Santa Marina basin study. Taking place from 1994 to present, this study had an unheard of dense surface automated meteorological station array of up to 5 meteorological buoys, 4 oil platforms, 2 island stations, and 11 coastal stations within 1 km of the beach. Most of the land stations are maintained by other projects. Only a large, a well funded project with backed by an agency with the long-view could dedicate the resources and effort into filling the mesoscale "holes" and maintaining long-term, remotely located stations. The result of the MMS funded project is a sufficiently dense surface station array to resolve the along-coast and cross-coast atmospheric mesoscale wind structure. Great temporal and spatial variation is found in the wind, wind stress and the wind stress curl, during the extended summer season. The MM5 atmospheric mesoscale model with appropriate boundary layer physics and high-resolution horizontal and vertical grid structure successfully simulates the measured wind field from large scale down to the lower end of the mesoscale. Atmospheric models without appropriate resolution and boundary layer physics fail to capture significant mesoscale wind features. Satellite microwave wind measurements generally capture the offshore synoptic scale temporal and spatial scale in twice-a-day snap shots but fail in the crucial, innermost coastal waters and the diurnal scale.

  20. Validation of the Atmospheric Infrared Sounder Retrieval Products over China and Their Application in Numerical Model

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    The atmospheric infrared sounder (AIRS) instrument onboard Aqua Satellite is a high spectral resolution infrared sounder. In recent years, AIRS has gradually become the primary method of atmospheric vertical observations. To examine the validation of AIRS retrieval products (V3.0) over China, the AIRS surface air temperature retrievals were compared with the ground observations obtained from 540 meteorological stations in July 2004 and January 2005, respectively. The sources of errors were considerably discussed. Based on the error analysis, the AIRS retrieved surface air temperature products were systemically corrected. Moreover, the AIRS temperature and humidity profile retrievals were compared with T213numerical forecasting products. Because T213 forecasting products are not the actual atmospheric states,to further verify the validation, the AIRS temperature and humidity profile products were assimilated into the MM5 model through the analysis nudging. In this paper, the case on February 14, 2005 in North China was simulated in detail. Then, we investigated the effects of AIRS retrievals on snowfall, humidity field,vertical velocity field, divergence field, and cloud microphysical processes. The major results are: (1) the errors of AIRS retrieved surface air temperature products are largely systematic deviations, for which the influences of terrain altitude and surface types are the major reasons; (2) the differences between the AIRS atmospheric profile retrievals and T213 numerical prediction products in temperature are generally less than 2 K, the differences in relative humidity are generally less than 25%; and (3) the AIRS temperature and humidity retrieval products can adjust the model initial field, and thus can improve the capacity of snowfall simulation to some extent.

  1. Long-term simulations of European air quality using the Danish Eulerian Hemispheric Model

    Science.gov (United States)

    Mantzius Hansen, Kaj

    2010-05-01

    Effects of air quality on nature and human health have been on the agenda for several decades. Air quality monitoring sites have been established throughout Europe and several of the sites have been operating for more than two decades. Long term evaluation of air quality from specific monitoring sites or smaller regions has been performed in several studies. For studies of larger regions, models with comprehensive chemistry schemes have been developed and applied to study atmospheric transport, transformation and deposition of various air pollutants. With faster and faster computers, the development over the years has been towards more complex chemistry schemes and higher spatial and temporal resolution of model output. This often limits the studied period to single or a few years. We will present a study of European air quality covering 18 years, simulated with a state-of-the-art atmospheric chemistry transport model. The Danish Eulerian Hemispheric Model (DEHM) covers the majority of the Northern Hemisphere with a horizontal grid resolution of 150 km X 150 km. DEHM has 29 vertical layers in terrain-following sigma-coordinates extending up to a height of 100 hPa. Two-way nesting options with a nesting factor of three can be applied with higher resolution over a limited area of the model. At present the model can be run without nests or with one, two or three nests, each with grid resolutions of 50 km X 50 km, 16.7 km X 16.7 km, and 5.6 km X 5.6 km, respectively. The model includes a comprehensive chemistry scheme with more than 100 reactions and 67 atmospheric constituents, of which 4 relate to primary particulates (PM2.5, PM10, TSP and sea salt); other species are SOx, NOx, NHx, VOCs, and secondary inorganic particulates. DEHM is driven by meteorological data from the numerical weather prediction model MM5v3. One long-term simulation was performed with DEHM covering the period from 1989 to 2006. The predicted concentrations were evaluated against measurements

  2. Building Models and Building Modelling

    DEFF Research Database (Denmark)

    Jørgensen, Kaj; Skauge, Jørn

    2008-01-01

    I rapportens indledende kapitel beskrives de primære begreber vedrørende bygningsmodeller og nogle fundamentale forhold vedrørende computerbaseret modulering bliver opstillet. Desuden bliver forskellen mellem tegneprogrammer og bygnings­model­lerings­programmer beskrevet. Vigtige aspekter om comp...

  3. Sensitivity of Turbine-Height Wind Speeds to Parameters in Planetary Boundary-Layer and Surface-Layer Schemes in the Weather Research and Forecasting Model

    Science.gov (United States)

    Yang, Ben; Qian, Yun; Berg, Larry K.; Ma, Po-Lun; Wharton, Sonia; Bulaevskaya, Vera; Yan, Huiping; Hou, Zhangshuan; Shaw, William J.

    2017-01-01

    We evaluate the sensitivity of simulated turbine-height wind speeds to 26 parameters within the Mellor-Yamada-Nakanishi-Niino (MYNN) planetary boundary-layer scheme and MM5 surface-layer scheme of the Weather Research and Forecasting model over an area of complex terrain. An efficient sampling algorithm and generalized linear model are used to explore the multiple-dimensional parameter space and quantify the parametric sensitivity of simulated turbine-height wind speeds. The results indicate that most of the variability in the ensemble simulations is due to parameters related to the dissipation of turbulent kinetic energy (TKE), Prandtl number, turbulent length scales, surface roughness, and the von Kármán constant. The parameter associated with the TKE dissipation rate is found to be most important, and a larger dissipation rate produces larger hub-height wind speeds. A larger Prandtl number results in smaller nighttime wind speeds. Increasing surface roughness reduces the frequencies of both extremely weak and strong airflows, implying a reduction in the variability of wind speed. All of the above parameters significantly affect the vertical profiles of wind speed and the magnitude of wind shear. The relative contributions of individual parameters are found to be dependent on both the terrain slope and atmospheric stability.

  4. Sensitivity of Turbine-Height Wind Speeds to Parameters in Planetary Boundary-Layer and Surface-Layer Schemes in the Weather Research and Forecasting Model

    Science.gov (United States)

    Yang, Ben; Qian, Yun; Berg, Larry K.; Ma, Po-Lun; Wharton, Sonia; Bulaevskaya, Vera; Yan, Huiping; Hou, Zhangshuan; Shaw, William J.

    2016-07-01

    We evaluate the sensitivity of simulated turbine-height wind speeds to 26 parameters within the Mellor-Yamada-Nakanishi-Niino (MYNN) planetary boundary-layer scheme and MM5 surface-layer scheme of the Weather Research and Forecasting model over an area of complex terrain. An efficient sampling algorithm and generalized linear model are used to explore the multiple-dimensional parameter space and quantify the parametric sensitivity of simulated turbine-height wind speeds. The results indicate that most of the variability in the ensemble simulations is due to parameters related to the dissipation of turbulent kinetic energy (TKE), Prandtl number, turbulent length scales, surface roughness, and the von Kármán constant. The parameter associated with the TKE dissipation rate is found to be most important, and a larger dissipation rate produces larger hub-height wind speeds. A larger Prandtl number results in smaller nighttime wind speeds. Increasing surface roughness reduces the frequencies of both extremely weak and strong airflows, implying a reduction in the variability of wind speed. All of the above parameters significantly affect the vertical profiles of wind speed and the magnitude of wind shear. The relative contributions of individual parameters are found to be dependent on both the terrain slope and atmospheric stability.

  5. Molecular Modelling

    Directory of Open Access Journals (Sweden)

    Aarti Sharma

    2009-12-01

    Full Text Available

    The use of computational chemistry in the development of novel pharmaceuticals is becoming an increasingly important
    tool. In the past, drugs were simply screened for effectiveness. The recent advances in computing power and
    the exponential growth of the knowledge of protein structures have made it possible for organic compounds to tailored to
    decrease harmful side effects and increase the potency. This article provides a detailed description of the techniques
    employed in molecular modeling. Molecular modelling is a rapidly developing discipline, and has been supported from
    the dramatic improvements in computer hardware and software in recent years.

  6. Cheating models

    DEFF Research Database (Denmark)

    Arnoldi, Jakob

    The article discusses the use of algorithmic models for so-called High Frequency Trading (HFT) in finance. HFT is controversial yet widespread in modern financial markets. It is a form of automated trading technology which critics among other things claim can lead to market manipulation. Drawing...... on two cases, this article shows that manipulation more likely happens in the reverse way, meaning that human traders attempt to make algorithms ‘make mistakes’ or ‘mislead’ algos. Thus, it is algorithmic models, not humans, that are manipulated. Such manipulation poses challenges for security exchanges....... The article analyses these challenges and argues that we witness a new post-social form of human-technology interaction that will lead to a reconfiguration of professional codes for financial trading....

  7. Acyclic models

    CERN Document Server

    Barr, Michael

    2002-01-01

    Acyclic models is a method heavily used to analyze and compare various homology and cohomology theories appearing in topology and algebra. This book is the first attempt to put together in a concise form this important technique and to include all the necessary background. It presents a brief introduction to category theory and homological algebra. The author then gives the background of the theory of differential modules and chain complexes over an abelian category to state the main acyclic models theorem, generalizing and systemizing the earlier material. This is then applied to various cohomology theories in algebra and topology. The volume could be used as a text for a course that combines homological algebra and algebraic topology. Required background includes a standard course in abstract algebra and some knowledge of topology. The volume contains many exercises. It is also suitable as a reference work for researchers.

  8. Nuclear Models

    Science.gov (United States)

    Fossión, Rubén

    2010-09-01

    The atomic nucleus is a typical example of a many-body problem. On the one hand, the number of nucleons (protons and neutrons) that constitute the nucleus is too large to allow for exact calculations. On the other hand, the number of constituent particles is too small for the individual nuclear excitation states to be explained by statistical methods. Another problem, particular for the atomic nucleus, is that the nucleon-nucleon (n-n) interaction is not one of the fundamental forces of Nature, and is hard to put in a single closed equation. The nucleon-nucleon interaction also behaves differently between two free nucleons (bare interaction) and between two nucleons in the nuclear medium (dressed interaction). Because of the above reasons, specific nuclear many-body models have been devised of which each one sheds light on some selected aspects of nuclear structure. Only combining the viewpoints of different models, a global insight of the atomic nucleus can be gained. In this chapter, we revise the the Nuclear Shell Model as an example of the microscopic approach, and the Collective Model as an example of the geometric approach. Finally, we study the statistical properties of nuclear spectra, basing on symmetry principles, to find out whether there is quantum chaos in the atomic nucleus. All three major approaches have been rewarded with the Nobel Prize of Physics. In the text, we will stress how each approach introduces its own series of approximations to reduce the prohibitingly large number of degrees of freedom of the full many-body problem to a smaller manageable number of effective degrees of freedom.

  9. Modelling Behaviour

    DEFF Research Database (Denmark)

    2015-01-01

    This book reflects and expands on the current trend in the building industry to understand, simulate and ultimately design buildings by taking into consideration the interlinked elements and forces that act on them. This approach overcomes the traditional, exclusive focus on building tasks, while....... The chapter authors were invited speakers at the 5th Symposium "Modelling Behaviour", which took place at the CITA in Copenhagen in September 2015....

  10. Modeling Minds

    DEFF Research Database (Denmark)

    Michael, John

    others' minds. Then (2), in order to bring to light some possible justifications, as well as hazards and criticisms of the methodology of looking time tests, I will take a closer look at the concept of folk psychology and will focus on the idea that folk psychology involves using oneself as a model...... of other people in order to predict and understand their behavior. Finally (3), I will discuss the historical location and significance of the emergence of looking time tests...

  11. Modeling biomembranes.

    Energy Technology Data Exchange (ETDEWEB)

    Plimpton, Steven James; Heffernan, Julieanne; Sasaki, Darryl Yoshio; Frischknecht, Amalie Lucile; Stevens, Mark Jackson; Frink, Laura J. Douglas

    2005-11-01

    Understanding the properties and behavior of biomembranes is fundamental to many biological processes and technologies. Microdomains in biomembranes or ''lipid rafts'' are now known to be an integral part of cell signaling, vesicle formation, fusion processes, protein trafficking, and viral and toxin infection processes. Understanding how microdomains form, how they depend on membrane constituents, and how they act not only has biological implications, but also will impact Sandia's effort in development of membranes that structurally adapt to their environment in a controlled manner. To provide such understanding, we created physically-based models of biomembranes. Molecular dynamics (MD) simulations and classical density functional theory (DFT) calculations using these models were applied to phenomena such as microdomain formation, membrane fusion, pattern formation, and protein insertion. Because lipid dynamics and self-organization in membranes occur on length and time scales beyond atomistic MD, we used coarse-grained models of double tail lipid molecules that spontaneously self-assemble into bilayers. DFT provided equilibrium information on membrane structure. Experimental work was performed to further help elucidate the fundamental membrane organization principles.

  12. Model Construct Based Enterprise Model Architecture and Its Modeling Approach

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    In order to support enterprise integration, a kind of model construct based enterprise model architecture and its modeling approach are studied in this paper. First, the structural makeup and internal relationships of enterprise model architecture are discussed. Then, the concept of reusable model construct (MC) which belongs to the control view and can help to derive other views is proposed. The modeling approach based on model construct consists of three steps, reference model architecture synthesis, enterprise model customization, system design and implementation. According to MC based modeling approach a case study with the background of one-kind-product machinery manufacturing enterprises is illustrated. It is shown that proposal model construct based enterprise model architecture and modeling approach are practical and efficient.

  13. Modelling Chemical Patterns of Atmospheric Polycyclic Aromatic Hydrocarbons (PAHs) in the Iberian Peninsula

    Science.gov (United States)

    Ratola, Nuno; Jiménez-Guerrero, Pedro

    2013-04-01

    Semi-volatile organic compounds (SVOCs) such as PBDEs, PCBs, organochlorine pesticides (OCPs) or PAHs, are widespread and generated in a multitude of anthropogenic (and natural for PAHs) processes and although they are found in the environment at low concentrations, possess an extraordinary carcinogenic capacity (Baussant et al., 2001) and high ecotoxicity due to their persistence in different matrices (air, soil, water, living organisms). In particular, PAHs are originated by combustion processes or release from fossil fuels and can be transported in the atmosphere over long distances in gaseous or particulate matter (Baek et al., 1991). The establishment of strategies for sampling and chemical transport modelling of SVOCs in the atmosphere aiming the definition and validation of the spatial, temporal and chemical transport patterns of contaminants can be achieved by an integrated system of third-generation models that represent the current state of knowledge in air quality modelling and experimental data collected in field campaigns. This has implications in the fields of meteorology, atmospheric chemistry and even climate change. In this case, an extensive database already obtained on levels of atmospheric PAHs from biomonitoring schemes in the Iberian Peninsula fuelled the establishment of the first models of behaviour for PAHs. The modelling system WRF+CHIMERE was implemented with high spatial and temporal resolution to the Iberian Peninsula in this first task (9 km for the Iberian Peninsula, 3 km to Portugal, 1 hour), using PAHs atmospheric levels collected over a year-long sampling scheme comprising 4 campaigns (one per season) in over 30 sites. Daily information on meteorological parameters such as air temperature, humidity, rainfall or wind speed and direction was collected from the weather stations closest to the sampling sites. Diagnosis and forecasts of these meteorological variables using MM5 or WRF were used to feed a chemistry transport model

  14. DTN Modeling in OPNET Modeler

    Directory of Open Access Journals (Sweden)

    PAPAJ Jan

    2014-05-01

    Full Text Available Traditional wireless networks use the concept of the point-to-point forwarding inherited from reliable wired networks which seems to be not ideal for wireless environment. New emerging applications and networks operate mostly disconnected. So-called Delay-Tolerant networks (DTNs are receiving increasing attentions from both academia and industry. DTNs introduced a store-carry-and-forward concept solving the problem of intermittent connectivity. Behavior of such networks is verified by real models, computer simulation or combination of the both approaches. Computer simulation has become the primary and cost effective tool for evaluating the performance of the DTNs. OPNET modeler is our target simulation tool and we wanted to spread OPNET’s simulation opportunity towards DTN. We implemented bundle protocol to OPNET modeler allowing simulate cases based on bundle concept as epidemic forwarding which relies on flooding the network with messages and the forwarding algorithm based on the history of past encounters (PRoPHET. The implementation details will be provided in article.

  15. A Model

    Institute of Scientific and Technical Information of China (English)

    Liu Zhiyang

    2011-01-01

    Similar to ISO Technical Committees,SAC Technical Committees undertake the management and coordination of standard's development and amendments in various sectors in industry,playing the role as a bridge among enterprises,research institutions and the governmental standardization administration.How to fully play the essential role is the vital issue SAC has been committing to resolve.Among hundreds of SAC TCs,one stands out in knitting together those isolated,scattered,but highly competitive enterprises in the same industry with the "Standards" thread,and achieving remarkable results in promoting industry development with standardization.It sets a role model for other TCs.

  16. Performance of a coupled lagged ensemble weather and river runoff prediction model system for the Alpine Ammer River catchment

    Science.gov (United States)

    Smiatek, G.; Kunstmann, H.; Werhahn, J.

    2012-04-01

    The Ammer River catchment located in the Bavarian Ammergau Alps and alpine forelands, Germany, represents with elevations reaching 2185 m and annual mean precipitation between1100 and 2000 mm a very demanding test ground for a river runoff prediction system. Large flooding events in 1999 and 2005 motivated the development of a physically based prediction tool in this area. Such a tool is the coupled high resolution numerical weather and river runoff forecasting system AM-POE that is being studied in several configurations in various experiments starting from the year 2005. Corner stones of the coupled system are the hydrological water balance model WaSiM-ETH run at 100 m grid resolution, the numerical weather prediction model (NWP) MM5 driven at 3.5 km grid cell resolution and the Perl Object Environment (POE) framework. POE implements the input data download from various sources, the input data provision via SOAP based WEB services as well as the runs of the hydrology model both with observed and with NWP predicted meteorology input. The one way coupled system utilizes a lagged ensemble prediction system (EPS) taking into account combination of recent and previous NWP forecasts. Results obtained in the years 2005-2011 reveal that river runoff simulations depict high correlation with observed runoff when driven with monitored observations in hindcast experiments. The ability to runoff forecasts is depending on lead times in the lagged ensemble prediction and shows still limitations resulting from errors in timing and total amount of the predicted precipitation in the complex mountainous area. The presentation describes the system implementation, and demonstrates the application of the POE framework in networking, distributed computing and in the setup of various experiments as well as long term results of the system application in the years 2005 - 2011.

  17. Modelling Behaviour

    DEFF Research Database (Denmark)

    2015-01-01

    This book reflects and expands on the current trend in the building industry to understand, simulate and ultimately design buildings by taking into consideration the interlinked elements and forces that act on them. This approach overcomes the traditional, exclusive focus on building tasks, while....... The chapter authors were invited speakers at the 5th Symposium "Modelling Behaviour", which took place at the CITA in Copenhagen in September 2015....... posing new challenges in all areas of the industry from material and structural to the urban scale. Contributions from invited experts, papers and case studies provide the reader with a comprehensive overview of the field, as well as perspectives from related disciplines, such as computer science...

  18. Econometric modelling

    Directory of Open Access Journals (Sweden)

    M. Alguacil Marí

    2017-08-01

    Full Text Available The current economic environment, together with the low scores obtained by our students in recent years, makes it necessary to incorporate new teaching methods. In this sense, econometric modelling provides a unique opportunity offering to the student with the basic tools to address the study of Econometrics in a deeper and novel way. In this article, this teaching method is described, presenting also an example based on a recent study carried out by two students of the Degree of Economics. Likewise, the success of this method is evaluated quantitatively in terms of academic performance. The results confirm our initial idea that the greater involvement of the student, as well as the need for a more complete knowledge of the subject, suppose a stimulus for the study of this subject. As evidence of this, we show how those students who opted for the method we propose here obtained higher qualifications than those that chose the traditional method.

  19. Modelling Defiguration

    DEFF Research Database (Denmark)

    Bork Petersen, Franziska

    2013-01-01

    For the presentation of his autumn/winter 2012 collection in Paris and subsequently in Copenhagen, Danish designer Henrik Vibskov installed a mobile catwalk. The article investigates the choreographic impact of this scenography on those who move through it. Drawing on Dance Studies, the analytical...... advantageous manner. Stepping on the catwalk’s sloping, moving surfaces decelerates the models’ walk and makes it cautious, hesitant and shaky: suddenly the models lack exactly the affirmative, staccato, striving quality of motion, and the condescending expression that they perform on most contemporary...... catwalks. Vibskov’s catwalk induces what the dance scholar Gabriele Brandstetter has labelled a ‘defigurative choregoraphy’: a straying from definitions, which exist in ballet as in other movement-based genres, of how a figure should move and appear (1998). The catwalk scenography in this instance...

  20. On Activity modelling in process modeling

    Directory of Open Access Journals (Sweden)

    Dorel Aiordachioaie

    2001-12-01

    Full Text Available The paper is looking to the dynamic feature of the meta-models of the process modelling process, the time. Some principles are considered and discussed as main dimensions of any modelling activity: the compatibility of the substances, the equipresence of phenomena and the solvability of the model. The activity models are considered and represented at meta-level.

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

    Science.gov (United States)

    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.

  2. Assimilation of Sentinel-1 estimates of Precipitable Water Vapor (PWV) into a Numerical Weather Model for a more accurate forecast of extreme weather events

    Science.gov (United States)

    Mateus, Pedro; Nico, Giovanni; Catalao, Joao

    2017-04-01

    In the last two decades, SAR interferometry has been used to obtain maps of Precipitable Water Vapor (PWV).This maps are characterized by their high spatial resolution when compared to the currently available PWV measurements (e.g. GNSS, radiometers or radiosondes). Several previous works have shown that assimilating PWV values, mainly derived from GNSS observations, into Numerical Weather Models (NWMs) can significantly improve rainfall predictions.It is noteworthy that the PWV-derived from GNSS observations have a high temporal resolution but a low spatialone. In addition, there are many regions without any GNSS stations, where temporal and spatial distribution of PWV areonly available through satellite measurements. The first attempt to assimilate InSAR-derived maps of PWV (InSAR-PWV) into a NWM was made by Pichelli et al. [1].They used InSAR-PWV maps obtained from ENVISAT-ASAR images and the mesoscale weather prediction model MM5 over the city of Rome, Italy. The statistical indices show that the InSAR-PWVdata assimilation improves the forecast of weak to moderateprecipitation (model over the city of Lisbon, Portugal, during a light rain event not forecast by the model.Results showed that after data assimilation, there is a bias correction of the PWV field and an improvement in the forecast of the weakto moderate rainfall up to 9 h after the assimilation time. We used, for the first time, the Weather Research and Forecast Data Assimilation (WRFDA) model, at micro-scale resolutions (3 km), over the Iberian Peninsula (focusing on the southern region of Spain) and during a convective cell associated with a local heavy rainfall event, to study the impact of assimilation PWV maps obtained from SAR interferometric phase calculated using images acquired by the Sentinel-1 satellite. It's worth noting that, in this case, the model without assimilation PWV maps fails to reproduce the amount and the region of heavy rainfall. The assimilation of InSAR-PWV maps with high

  3. Digitale Medien, freie Bildung und vernetztes Wissen

    OpenAIRE

    Sven Stollfuß

    2015-01-01

    Rezension zu: Petra Missomelius, Wolfgang Sützl, Theo Hug, Petra Grell und Rudolf Kammerl, Hrsg. Medien – Wissen – Bildung: Freie Bildungsmedien und Digitale Archive. Innsbruck: innsbruck university press, 2014

  4. Digitale Medien, freie Bildung und vernetztes Wissen

    Directory of Open Access Journals (Sweden)

    Sven Stollfuß

    2015-05-01

    Full Text Available Rezension zu: Petra Missomelius, Wolfgang Sützl, Theo Hug, Petra Grell und Rudolf Kammerl, Hrsg. Medien – Wissen – Bildung: Freie Bildungsmedien und Digitale Archive. Innsbruck: innsbruck university press, 2014

  5. A Finite Axiomatization of G-Dependence

    OpenAIRE

    Paolini, Gianluca

    2015-01-01

    We show that a form of dependence known as G-dependence (originally introduced by Grelling) admits a very natural finite axiomatization, as well as Armstrong relations. We also give an explicit translation between functional dependence and G-dependence.

  6. Towards a Multi Business Model Innovation Model

    DEFF Research Database (Denmark)

    Lindgren, Peter; Jørgensen, Rasmus

    2012-01-01

    This paper studies the evolution of business model (BM) innovations related to a multi business model framework. The paper tries to answer the research questions: • What are the requirements for a multi business model innovation model (BMIM)? • How should a multi business model innovation model...... look like? Different generations of BMIMs are initially studied in the context of laying the baseline for how next generation multi BM Innovation model (BMIM) should look like. All generations of models are analyzed with the purpose of comparing the characteristics and challenges of previous...

  7. Better Language Models with Model Merging

    CERN Document Server

    Brants, T

    1996-01-01

    This paper investigates model merging, a technique for deriving Markov models from text or speech corpora. Models are derived by starting with a large and specific model and by successively combining states to build smaller and more general models. We present methods to reduce the time complexity of the algorithm and report on experiments on deriving language models for a speech recognition task. The experiments show the advantage of model merging over the standard bigram approach. The merged model assigns a lower perplexity to the test set and uses considerably fewer states.

  8. Model Selection Principles in Misspecified Models

    CERN Document Server

    Lv, Jinchi

    2010-01-01

    Model selection is of fundamental importance to high dimensional modeling featured in many contemporary applications. Classical principles of model selection include the Kullback-Leibler divergence principle and the Bayesian principle, which lead to the Akaike information criterion and Bayesian information criterion when models are correctly specified. Yet model misspecification is unavoidable when we have no knowledge of the true model or when we have the correct family of distributions but miss some true predictor. In this paper, we propose a family of semi-Bayesian principles for model selection in misspecified models, which combine the strengths of the two well-known principles. We derive asymptotic expansions of the semi-Bayesian principles in misspecified generalized linear models, which give the new semi-Bayesian information criteria (SIC). A specific form of SIC admits a natural decomposition into the negative maximum quasi-log-likelihood, a penalty on model dimensionality, and a penalty on model miss...

  9. Evaluation of near-surface temperature, humidity, and equivalent temperature from regional climate models applied in type II downscaling

    Science.gov (United States)

    Pryor, S. C.; Schoof, J. T.

    2016-04-01

    Atmosphere-surface interactions are important components of local and regional climates due to their key roles in dictating the surface energy balance and partitioning of energy transfer between sensible and latent heat. The degree to which regional climate models (RCMs) represent these processes with veracity is incompletely characterized, as is their ability to capture the drivers of, and magnitude of, equivalent temperature (Te). This leads to uncertainty in the simulation of near-surface temperature and humidity regimes and the extreme heat events of relevance to human health, in both the contemporary and possible future climate states. Reanalysis-nested RCM simulations are evaluated to determine the degree to which they represent the probability distributions of temperature (T), dew point temperature (Td), specific humidity (q) and Te over the central U.S., the conditional probabilities of Td|T, and the coupling of T, q, and Te to soil moisture and meridional moisture advection within the boundary layer (adv(Te)). Output from all RCMs exhibits discrepancies relative to observationally derived time series of near-surface T, q, Td, and Te, and use of a single layer for soil moisture by one of the RCMs does not appear to substantially degrade the simulations of near-surface T and q relative to RCMs that employ a four-layer soil model. Output from MM5I exhibits highest fidelity for the majority of skill metrics applied herein, and importantly most realistically simulates both the coupling of T and Td, and the expected relationships of boundary layer adv(Te) and soil moisture with near-surface T and q.

  10. Comparison of eye-tracking success in laser in situ keratomileusis after flap creation with 2 femtosecond laser models.

    Science.gov (United States)

    Luengo Gimeno, Federico; Chan, Cordelia M L; Li, Lim; Tan, Donald T H; Mehta, Jodhbir S

    2011-03-01

    To determine the efficiency of an eye tracker after laser in situ keratomileusis (LASIK) flap creation with 1 of 2 femtosecond laser models. Tertiary referral center, Singapore National Eye Center, Singapore. Randomized clinical trial. The LASIK flap was created with an IntraLase (Group A) or a VisuMax (Group B) femtosecond laser. An Advanced Control Eye Tracker was initiated 3 times to obtain iris recognition. Eye tracking was considered successful if the eye movements could be followed despite the presence or absence of an opaque bubble layer (OBL). Univariate-multivariate logistic regression analysis was performed. Preoperatively, the mean values (ranges) of the 87 eyes were sphere, -5.64 diopters (D) ± 2.17 (SD) (-9.75 to -0.25 D); cylinder 1.65 ± 1.63 D (-3.75 to 0.00 D); optical zone, 6.34 ± 0.20 mm (5.6 to 7.0 mm); keratometry, 43.48 ± 1.32 D (40.1 to 42.8 D); flap thickness, 109.30 + 5.21 μm (90 to 115 μm). Eye tracking was successful in 38 (90.5%) of 42 eyes in Group A and 43 (95.6%) of 45 eyes in Group B. No specific type of OBL was seen in either group. The LASIK was completed in all eyes. There was a statistically significant association between positive tracking and a smaller optical zone (P=.03). There were no statistically significant differences in eye tracking between the 2 femtosecond lasers. Eye tracking was achieved in more than 90% of cases after LASIK flap creation with 1 of 2 femtosecond laser models, even in the presence of an OBL. Copyright © 2011 ASCRS and ESCRS. Published by Elsevier Inc. All rights reserved.

  11. The IMACLIM model; Le modele IMACLIM

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2003-07-01

    This document provides annexes to the IMACLIM model which propose an actualized description of IMACLIM, model allowing the design of an evaluation tool of the greenhouse gases reduction policies. The model is described in a version coupled with the POLES, technical and economical model of the energy industry. Notations, equations, sources, processing and specifications are proposed and detailed. (A.L.B.)

  12. Building Mental Models by Dissecting Physical Models

    Science.gov (United States)

    Srivastava, Anveshna

    2016-01-01

    When students build physical models from prefabricated components to learn about model systems, there is an implicit trade-off between the physical degrees of freedom in building the model and the intensity of instructor supervision needed. Models that are too flexible, permitting multiple possible constructions require greater supervision to…

  13. The IMACLIM model; Le modele IMACLIM

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2003-07-01

    This document provides annexes to the IMACLIM model which propose an actualized description of IMACLIM, model allowing the design of an evaluation tool of the greenhouse gases reduction policies. The model is described in a version coupled with the POLES, technical and economical model of the energy industry. Notations, equations, sources, processing and specifications are proposed and detailed. (A.L.B.)

  14. Spatial Growth Modeling and High Resolution Remote Sensing Data Coupled with Air Quality Modeling to Assess the Impact of Atlanta, Georgia on the Local and Regional Environment

    Science.gov (United States)

    Quattrochi, Dale A.; Estes, Maurice G., Jr.; Crosson, William; Johnson, Hoyt; Khan, Maudood

    2006-01-01

    The growth of cities, both in population and areal extent, appears as an inexorable process. Urbanization continues at a rapid rate, and it is estimated that by the year 2025, 60 percent of the world s population will live in cities. Urban expansion has profound impacts on a host of biophysical, environmental, and atmospheric processes within an urban ecosystems perspective. A reduction in air quality over cities is a major result of these impacts. Because of its complexity, the urban landscape is not adequately captured in air quality models such as the Community Multiscale Air Quality (CMAQ) model that is used to assess whether urban areas are in attainment of EPA air quality standards, primarily for ground level ozone. This inadequacy of the CMAQ model to sufficiently respond to the heterogeneous nature of the urban landscape can impact how well the model predicts ozone levels over metropolitan areas and ultimately, whether cities exceed EPA ozone air quality standards. We are exploring the utility of high-resolution remote sensing data and urban spatial growth modeling (SGM) projections as improved inputs to a meteorological/air quality modeling system focusing on the Atlanta, Georgia metropolitan area as a case study. These growth projections include business as usual and smart growth scenarios out to 2030. The growth projections illustrate the effects of employing urban heat island mitigation strategies, such as increasing tree canopy and albedo across the Atlanta metro area, which in turn, are used to model how air temperature can potentially be moderated as impacts on elevating ground-level ozone, as opposed to not utilizing heat island mitigation strategies. The National Land Cover Dataset at 30m resolution is being used as the land use/land cover input and aggregated to the 4km scale for the MM5 mesoscale meteorological model and the CMAQ modeling schemes. Use of these data has been found to better characterize low density/suburban development as compared

  15. Remote Sensing and Spatial Growth Modeling Coupled with Air Quality Modeling to Assess the Impact of Atlanta, Georgia on the Local and Regional Environment

    Science.gov (United States)

    Quattrochi, Dale A.; Estes, Maurice G., Jr.; Crosson, William; Khan, Maudood

    2006-01-01

    island mitigation strategies. The National Land Cover Dataset at 30m resolution is being used as the land use/land cover input and aggregated to the 4km scale for the MM5 mesoscale meteorological model and the (CMAQ) modeling schemes. Use of these data have been found to better characterize low density/suburban development as compared with USGS 1km land use/land cover data that have traditionally been used in modeling. Air quality prediction for future scenarios to 2030 is being facilitated by land use projections using a spatial growth model. Land use projections were developed using the 2030 Regional Transportation Plan developed by the Atlanta Regional Commission, the regional planning agency for the area. This allows the State Environmental Protection agency to evaluate how these transportation plans will affect future air quality. The coupled SGM and air quality modeling approach provides insight on what the impacts of Atlanta s growth will be on the local and regional environment and exists as a mechanism that can be used by policy makers to make rationale decisions on urban growth and sustainability for the metropolitan area in the future.

  16. Modelling live forensic acquisition

    CSIR Research Space (South Africa)

    Grobler, MM

    2009-06-01

    Full Text Available This paper discusses the development of a South African model for Live Forensic Acquisition - Liforac. The Liforac model is a comprehensive model that presents a range of aspects related to Live Forensic Acquisition. The model provides forensic...

  17. WRF4G project: Adaptation of WRF Model to Distributed Computing Infrastructures

    Science.gov (United States)

    Cofino, Antonio S.; Fernández Quiruelas, Valvanuz; García Díez, Markel; Blanco Real, Jose C.; Fernández, Jesús

    2013-04-01

    Nowadays Grid Computing is powerful computational tool which is ready to be used for scientific community in different areas (such as biomedicine, astrophysics, climate, etc.). However, the use of this distributed computing infrastructures (DCI) is not yet common practice in climate research, and only a few teams and applications in this area take advantage of this infrastructure. Thus, the first objective of this project is to popularize the use of this technology in the atmospheric sciences area. In order to achieve this objective, one of the most used applications has been taken (WRF; a limited- area model, successor of the MM5 model), that has a user community formed by more than 8000 researchers worldwide. This community develop its research activity on different areas and could benefit from the advantages of Grid resources (case study simulations, regional hind-cast/forecast, sensitivity studies, etc.). The WRF model is been used as input by many energy and natural hazards community, therefore those community will also benefit. However, Grid infrastructures have some drawbacks for the execution of applications that make an intensive use of CPU and memory for a long period of time. This makes necessary to develop a specific framework (middleware). This middleware encapsulates the application and provides appropriate services for the monitoring and management of the jobs and the data. Thus, the second objective of the project consists on the development of a generic adaptation of WRF for Grid (WRF4G), to be distributed as open-source and to be integrated in the official WRF development cycle. The use of this WRF adaptation should be transparent and useful to face any of the previously described studies, and avoid any of the problems of the Grid infrastructure. Moreover it should simplify the access to the Grid infrastructures for the research teams, and also to free them from the technical and computational aspects of the use of the Grid. Finally, in order to

  18. Continuous Time Model Estimation

    OpenAIRE

    Carl Chiarella; Shenhuai Gao

    2004-01-01

    This paper introduces an easy to follow method for continuous time model estimation. It serves as an introduction on how to convert a state space model from continuous time to discrete time, how to decompose a hybrid stochastic model into a trend model plus a noise model, how to estimate the trend model by simulation, and how to calculate standard errors from estimation of the noise model. It also discusses the numerical difficulties involved in discrete time models that bring about the unit ...

  19. Comparative Protein Structure Modeling Using MODELLER.

    Science.gov (United States)

    Webb, Benjamin; Sali, Andrej

    2016-06-20

    Comparative protein structure modeling predicts the three-dimensional structure of a given protein sequence (target) based primarily on its alignment to one or more proteins of known structure (templates). The prediction process consists of fold assignment, target-template alignment, model building, and model evaluation. This unit describes how to calculate comparative models using the program MODELLER and how to use the ModBase database of such models, and discusses all four steps of comparative modeling, frequently observed errors, and some applications. Modeling lactate dehydrogenase from Trichomonas vaginalis (TvLDH) is described as an example. The download and installation of the MODELLER software is also described. © 2016 by John Wiley & Sons, Inc.

  20. Concept Modeling vs. Data modeling in Practice

    DEFF Research Database (Denmark)

    Madsen, Bodil Nistrup; Erdman Thomsen, Hanne

    2015-01-01

    account of the inheritance of characteristics and allows us to introduce a number of principles and constraints which render concept modeling more coherent than earlier approaches. Second, we explain how terminological ontologies can be used as the basis for developing conceptual and logical data models......This chapter shows the usefulness of terminological concept modeling as a first step in data modeling. First, we introduce terminological concept modeling with terminological ontologies, i.e. concept systems enriched with characteristics modeled as feature specifications. This enables a formal...

  1. Business Model Innovation

    OpenAIRE

    Dodgson, Mark; Gann, David; Phillips, Nelson; Massa, Lorenzo; Tucci, Christopher

    2014-01-01

    The chapter offers a broad review of the literature at the nexus between Business Models and innovation studies, and examines the notion of Business Model Innovation in three different situations: Business Model Design in newly formed organizations, Business Model Reconfiguration in incumbent firms, and Business Model Innovation in the broad context of sustainability. Tools and perspectives to make sense of Business Models and support managers and entrepreneurs in dealing with Business Model ...

  2. Modeling cholera outbreaks.

    Science.gov (United States)

    Chao, Dennis L; Longini, Ira M; Morris, J Glenn

    2014-01-01

    Mathematical modeling can be a valuable tool for studying infectious disease outbreak dynamics and simulating the effects of possible interventions. Here, we describe approaches to modeling cholera outbreaks and how models have been applied to explore intervention strategies, particularly in Haiti. Mathematical models can play an important role in formulating and evaluating complex cholera outbreak response options. Major challenges to cholera modeling are insufficient data for calibrating models and the need to tailor models for different outbreak scenarios.

  3. Modeling cholera outbreaks

    Science.gov (United States)

    Longini, Ira M.; Morris, J. Glenn

    2014-01-01

    Mathematical modeling can be a valuable tool for studying infectious disease outbreak dynamics and simulating the effects of possible interventions. Here, we describe approaches to modeling cholera outbreaks and how models have been applied to explore intervention strategies, particularly in Haiti. Mathematical models can play an important role in formulating and evaluating complex cholera outbreak response options. Major challenges to cholera modeling are insufficient data for calibrating models and the need to tailor models for different outbreak scenarios. PMID:23412687

  4. Model Manipulation for End-User Modelers

    DEFF Research Database (Denmark)

    Acretoaie, Vlad

    of these proposals. To achieve its first goal, the thesis presents the findings of a Systematic Mapping Study showing that human factors topics are scarcely and relatively poorly addressed in model transformation research. Motivated by these findings, the thesis explores the requirements of end-user modelers......End-user modelers are domain experts who create and use models as part of their work. They are typically not Software Engineers, and have little or no programming and meta-modeling experience. However, using model manipulation languages developed in the context of Model-Driven Engineering often...... requires such experience. These languages are therefore only used by a small subset of the modelers that could, in theory, benefit from them. The goals of this thesis are to substantiate this observation, introduce the concepts and tools required to overcome it, and provide empirical evidence in support...

  5. Air Quality Dispersion Modeling - Alternative Models

    Science.gov (United States)

    Models, not listed in Appendix W, that can be used in regulatory applications with case-by-case justification to the Reviewing Authority as noted in Section 3.2, Use of Alternative Models, in Appendix W.

  6. From Product Models to Product State Models

    DEFF Research Database (Denmark)

    Larsen, Michael Holm

    1999-01-01

    A well-known technology designed to handle product data is Product Models. Product Models are in their current form not able to handle all types of product state information. Hence, the concept of a Product State Model (PSM) is proposed. The PSM and in particular how to model a PSM is the Research...... Object for this project. In the presentation, benefits and challenges of the PSM will be presented as a basis for the discussion....

  7. Measurement and Modeling: Infectious Disease Modeling

    NARCIS (Netherlands)

    Kretzschmar, MEE

    2016-01-01

    After some historical remarks about the development of mathematical theory for infectious disease dynamics we introduce a basic mathematical model for the spread of an infection with immunity. The concepts of the model are explained and the model equations are derived from first principles. Using th

  8. Modelling of Hydraulic Robot

    DEFF Research Database (Denmark)

    Madsen, Henrik; Zhou, Jianjun; Hansen, Lars Henrik

    1997-01-01

    This paper describes a case study of identifying the physical model (or the grey box model) of a hydraulic test robot. The obtained model is intended to provide a basis for model-based control of the robot. The physical model is formulated in continuous time and is derived by application...... of the laws of physics on the system. The unknown (or uncertain) parameters are estimated with Maximum Likelihood (ML) parameter estimation. The identified model has been evaluated by comparing the measurements with simulation of the model. The identified model was much more capable of describing the dynamics...... of the system than the deterministic model....

  9. Product and Process Modelling

    DEFF Research Database (Denmark)

    Cameron, Ian T.; Gani, Rafiqul

    This book covers the area of product and process modelling via a case study approach. It addresses a wide range of modelling applications with emphasis on modelling methodology and the subsequent in-depth analysis of mathematical models to gain insight via structural aspects of the models. These ...

  10. "Bohr's Atomic Model."

    Science.gov (United States)

    Willden, Jeff

    2001-01-01

    "Bohr's Atomic Model" is a small interactive multimedia program that introduces the viewer to a simplified model of the atom. This interactive simulation lets students build an atom using an atomic construction set. The underlying design methodology for "Bohr's Atomic Model" is model-centered instruction, which means the central model of the…

  11. Modelling of Hydraulic Robot

    DEFF Research Database (Denmark)

    Madsen, Henrik; Zhou, Jianjun; Hansen, Lars Henrik

    1997-01-01

    This paper describes a case study of identifying the physical model (or the grey box model) of a hydraulic test robot. The obtained model is intended to provide a basis for model-based control of the robot. The physical model is formulated in continuous time and is derived by application...

  12. Forest-fire models

    Science.gov (United States)

    Haiganoush Preisler; Alan Ager

    2013-01-01

    For applied mathematicians forest fire models refer mainly to a non-linear dynamic system often used to simulate spread of fire. For forest managers forest fire models may pertain to any of the three phases of fire management: prefire planning (fire risk models), fire suppression (fire behavior models), and postfire evaluation (fire effects and economic models). In...

  13. Solicited abstract: Global hydrological modeling and models

    Science.gov (United States)

    Xu, Chong-Yu

    2010-05-01

    The origins of rainfall-runoff modeling in the broad sense can be found in the middle of the 19th century arising in response to three types of engineering problems: (1) urban sewer design, (2) land reclamation drainage systems design, and (3) reservoir spillway design. Since then numerous empirical, conceptual and physically-based models are developed including event based models using unit hydrograph concept, Nash's linear reservoir models, HBV model, TOPMODEL, SHE model, etc. From the late 1980s, the evolution of global and continental-scale hydrology has placed new demands on hydrologic modellers. The macro-scale hydrological (global and regional scale) models were developed on the basis of the following motivations (Arenll, 1999). First, for a variety of operational and planning purposes, water resource managers responsible for large regions need to estimate the spatial variability of resources over large areas, at a spatial resolution finer than can be provided by observed data alone. Second, hydrologists and water managers are interested in the effects of land-use and climate variability and change over a large geographic domain. Third, there is an increasing need of using hydrologic models as a base to estimate point and non-point sources of pollution loading to streams. Fourth, hydrologists and atmospheric modellers have perceived weaknesses in the representation of hydrological processes in regional and global climate models, and developed global hydrological models to overcome the weaknesses of global climate models. Considerable progress in the development and application of global hydrological models has been achieved to date, however, large uncertainties still exist considering the model structure including large scale flow routing, parameterization, input data, etc. This presentation will focus on the global hydrological models, and the discussion includes (1) types of global hydrological models, (2) procedure of global hydrological model development

  14. Bayesian Model Selection and Statistical Modeling

    CERN Document Server

    Ando, Tomohiro

    2010-01-01

    Bayesian model selection is a fundamental part of the Bayesian statistical modeling process. The quality of these solutions usually depends on the goodness of the constructed Bayesian model. Realizing how crucial this issue is, many researchers and practitioners have been extensively investigating the Bayesian model selection problem. This book provides comprehensive explanations of the concepts and derivations of the Bayesian approach for model selection and related criteria, including the Bayes factor, the Bayesian information criterion (BIC), the generalized BIC, and the pseudo marginal lik

  15. From Numeric Models to Granular System Modeling

    Directory of Open Access Journals (Sweden)

    Witold Pedrycz

    2015-03-01

    To make this study self-contained, we briefly recall the key concepts of granular computing and demonstrate how this conceptual framework and its algorithmic fundamentals give rise to granular models. We discuss several representative formal setups used in describing and processing information granules including fuzzy sets, rough sets, and interval calculus. Key architectures of models dwell upon relationships among information granules. We demonstrate how information granularity and its optimization can be regarded as an important design asset to be exploited in system modeling and giving rise to granular models. With this regard, an important category of rule-based models along with their granular enrichments is studied in detail.

  16. Geologic Framework Model Analysis Model Report

    Energy Technology Data Exchange (ETDEWEB)

    R. Clayton

    2000-12-19

    The purpose of this report is to document the Geologic Framework Model (GFM), Version 3.1 (GFM3.1) with regard to data input, modeling methods, assumptions, uncertainties, limitations, and validation of the model results, qualification status of the model, and the differences between Version 3.1 and previous versions. The GFM represents a three-dimensional interpretation of the stratigraphy and structural features of the location of the potential Yucca Mountain radioactive waste repository. The GFM encompasses an area of 65 square miles (170 square kilometers) and a volume of 185 cubic miles (771 cubic kilometers). The boundaries of the GFM were chosen to encompass the most widely distributed set of exploratory boreholes (the Water Table or WT series) and to provide a geologic framework over the area of interest for hydrologic flow and radionuclide transport modeling through the unsaturated zone (UZ). The depth of the model is constrained by the inferred depth of the Tertiary-Paleozoic unconformity. The GFM was constructed from geologic map and borehole data. Additional information from measured stratigraphy sections, gravity profiles, and seismic profiles was also considered. This interim change notice (ICN) was prepared in accordance with the Technical Work Plan for the Integrated Site Model Process Model Report Revision 01 (CRWMS M&O 2000). The constraints, caveats, and limitations associated with this model are discussed in the appropriate text sections that follow. The GFM is one component of the Integrated Site Model (ISM) (Figure l), which has been developed to provide a consistent volumetric portrayal of the rock layers, rock properties, and mineralogy of the Yucca Mountain site. The ISM consists of three components: (1) Geologic Framework Model (GFM); (2) Rock Properties Model (RPM); and (3) Mineralogic Model (MM). The ISM merges the detailed project stratigraphy into model stratigraphic units that are most useful for the primary downstream models and the

  17. Model Theory and Applications

    CERN Document Server

    Mangani, P

    2011-01-01

    This title includes: Lectures - G.E. Sacks - Model theory and applications, and H.J. Keisler - Constructions in model theory; and, Seminars - M. Servi - SH formulas and generalized exponential, and J.A. Makowski - Topological model theory.

  18. Wildfire Risk Main Model

    Data.gov (United States)

    Earth Data Analysis Center, University of New Mexico — The model combines three modeled fire behavior parameters (rate of spread, flame length, crown fire potential) and one modeled ecological health measure (fire regime...

  19. Energy modelling software

    CSIR Research Space (South Africa)

    Osburn, L

    2010-01-01

    Full Text Available The construction industry has turned to energy modelling in order to assist them in reducing the amount of energy consumed by buildings. However, while the energy loads of buildings can be accurately modelled, energy models often under...

  20. Computational neurogenetic modeling

    CERN Document Server

    Benuskova, Lubica

    2010-01-01

    Computational Neurogenetic Modeling is a student text, introducing the scope and problems of a new scientific discipline - Computational Neurogenetic Modeling (CNGM). CNGM is concerned with the study and development of dynamic neuronal models for modeling brain functions with respect to genes and dynamic interactions between genes. These include neural network models and their integration with gene network models. This new area brings together knowledge from various scientific disciplines, such as computer and information science, neuroscience and cognitive science, genetics and molecular biol

  1. Predictive Models for Music

    OpenAIRE

    Paiement, Jean-François; Grandvalet, Yves; Bengio, Samy

    2008-01-01

    Modeling long-term dependencies in time series has proved very difficult to achieve with traditional machine learning methods. This problem occurs when considering music data. In this paper, we introduce generative models for melodies. We decompose melodic modeling into two subtasks. We first propose a rhythm model based on the distributions of distances between subsequences. Then, we define a generative model for melodies given chords and rhythms based on modeling sequences of Narmour featur...

  2. TRACKING CLIMATE MODELS

    Data.gov (United States)

    National Aeronautics and Space Administration — CLAIRE MONTELEONI*, GAVIN SCHMIDT, AND SHAILESH SAROHA* Climate models are complex mathematical models designed by meteorologists, geophysicists, and climate...

  3. Environmental Modeling Center

    Data.gov (United States)

    Federal Laboratory Consortium — The Environmental Modeling Center provides the computational tools to perform geostatistical analysis, to model ground water and atmospheric releases for comparison...

  4. Multilevel modeling using R

    CERN Document Server

    Finch, W Holmes; Kelley, Ken

    2014-01-01

    A powerful tool for analyzing nested designs in a variety of fields, multilevel/hierarchical modeling allows researchers to account for data collected at multiple levels. Multilevel Modeling Using R provides you with a helpful guide to conducting multilevel data modeling using the R software environment.After reviewing standard linear models, the authors present the basics of multilevel models and explain how to fit these models using R. They then show how to employ multilevel modeling with longitudinal data and demonstrate the valuable graphical options in R. The book also describes models fo

  5. Global Business Models

    DEFF Research Database (Denmark)

    Rask, Morten

    insight from the literature about business models, international product policy, international entry modes and globalization into a conceptual model of relevant design elements of global business models, enabling global business model innovation to deal with differences in a downstream perspective...... regarding the customer interface and in an upstream perspective regarding the supply infrastructure. The paper offers a coherent conceptual dynamic meta-model of global business model innovation. Students, scholars and managers within the field of international business can use this conceptualization...... to understand, to study, and to create global business model innovation. Managerial and research implications draw on the developed ideal type of global business model innovation....

  6. Continuous system modeling

    Science.gov (United States)

    Cellier, Francois E.

    1991-01-01

    A comprehensive and systematic introduction is presented for the concepts associated with 'modeling', involving the transition from a physical system down to an abstract description of that system in the form of a set of differential and/or difference equations, and basing its treatment of modeling on the mathematics of dynamical systems. Attention is given to the principles of passive electrical circuit modeling, planar mechanical systems modeling, hierarchical modular modeling of continuous systems, and bond-graph modeling. Also discussed are modeling in equilibrium thermodynamics, population dynamics, and system dynamics, inductive reasoning, artificial neural networks, and automated model synthesis.

  7. Understandings of 'Modelling'

    DEFF Research Database (Denmark)

    Andresen, Mette

    2007-01-01

    This paper meets the common critique of the teaching of non-authentic modelling in school mathematics. In the paper, non-authentic modelling is related to a change of view on the intentions of modelling from knowledge about applications of mathematical models to modelling for concept formation. Non......-authentic modelling is also linked with the potentials of exploration of ready-made models as a forerunner for more authentic modelling processes. The discussion includes analysis of an episode of students? work in the classroom, which serves to illustrate how concept formation may be linked to explorations of a non...

  8. Interfacing materials models with fire field models

    Energy Technology Data Exchange (ETDEWEB)

    Nicolette, V.F.; Tieszen, S.R.; Moya, J.L.

    1995-12-01

    For flame spread over solid materials, there has traditionally been a large technology gap between fundamental combustion research and the somewhat simplistic approaches used for practical, real-world applications. Recent advances in computational hardware and computational fluid dynamics (CFD)-based software have led to the development of fire field models. These models, when used in conjunction with material burning models, have the potential to bridge the gap between research and application by implementing physics-based engineering models in a transient, multi-dimensional tool. This paper discusses the coupling that is necessary between fire field models and burning material models for the simulation of solid material fires. Fire field models are capable of providing detailed information about the local fire environment. This information serves as an input to the solid material combustion submodel, which subsequently calculates the impact of the fire environment on the material. The response of the solid material (in terms of thermal response, decomposition, charring, and off-gassing) is then fed back into the field model as a source of mass, momentum and energy. The critical parameters which must be passed between the field model and the material burning model have been identified. Many computational issues must be addressed when developing such an interface. Some examples include the ability to track multiple fuels and species, local ignition criteria, and the need to use local grid refinement over the burning material of interest.

  9. Combustion modeling in a model combustor

    Institute of Scientific and Technical Information of China (English)

    L.Y.Jiang; I.Campbell; K.Su

    2007-01-01

    The flow-field of a propane-air diffusion flame combustor with interior and exterior conjugate heat transfers was numerically studied.Results obtained from four combustion models,combined with the re-normalization group (RNG) k-ε turbulence model,discrete ordinates radiation model and enhanced wall treatment are presented and discussed.The results are compared with a comprehensive database obtained from a series of experimental measurements.The flow patterns and the recirculation zone length in the combustion chamber are accurately predicted,and the mean axial velocities are in fairly good agreement with the experimental data,particularly at downstream sections for all four combustion models.The mean temperature profiles are captured fairly well by the eddy dissipation (EDS),probability density function (PDF),and laminar flamelet combustion models.However,the EDS-finite-rate combustion model fails to provide an acceptable temperature field.In general,the flamelet model illustrates little superiority over the PDF model,and to some extent the PDF model shows better performance than the EDS model.

  10. Regularized Structural Equation Modeling.

    Science.gov (United States)

    Jacobucci, Ross; Grimm, Kevin J; McArdle, John J

    A new method is proposed that extends the use of regularization in both lasso and ridge regression to structural equation models. The method is termed regularized structural equation modeling (RegSEM). RegSEM penalizes specific parameters in structural equation models, with the goal of creating easier to understand and simpler models. Although regularization has gained wide adoption in regression, very little has transferred to models with latent variables. By adding penalties to specific parameters in a structural equation model, researchers have a high level of flexibility in reducing model complexity, overcoming poor fitting models, and the creation of models that are more likely to generalize to new samples. The proposed method was evaluated through a simulation study, two illustrative examples involving a measurement model, and one empirical example involving the structural part of the model to demonstrate RegSEM's utility.

  11. Wastewater treatment models

    DEFF Research Database (Denmark)

    Gernaey, Krist; Sin, Gürkan

    2011-01-01

    The state-of-the-art level reached in modeling wastewater treatment plants (WWTPs) is reported. For suspended growth systems, WWTP models have evolved from simple description of biological removal of organic carbon and nitrogen in aeration tanks (ASM1 in 1987) to more advanced levels including...... of WWTP modeling by linking the wastewater treatment line with the sludge handling line in one modeling platform. Application of WWTP models is currently rather time consuming and thus expensive due to the high model complexity, and requires a great deal of process knowledge and modeling expertise....... Efficient and good modeling practice therefore requires the use of a proper set of guidelines, thus grounding the modeling studies on a general and systematic framework. Last but not least, general limitations of WWTP models – more specifically activated sludge models – are introduced since these define...

  12. Wastewater Treatment Models

    DEFF Research Database (Denmark)

    Gernaey, Krist; Sin, Gürkan

    2008-01-01

    The state-of-the-art level reached in modeling wastewater treatment plants (WWTPs) is reported. For suspended growth systems, WWTP models have evolved from simple description of biological removal of organic carbon and nitrogen in aeration tanks (ASM1 in 1987) to more advanced levels including...... the practice of WWTP modeling by linking the wastewater treatment line with the sludge handling line in one modeling platform. Application of WWTP models is currently rather time consuming and thus expensive due to the high model complexity, and requires a great deal of process knowledge and modeling expertise....... Efficient and good modeling practice therefore requires the use of a proper set of guidelines, thus grounding the modeling studies on a general and systematic framework. Last but not least, general limitations of WWTP models – more specifically, activated sludge models – are introduced since these define...

  13. ROCK PROPERTIES MODEL ANALYSIS MODEL REPORT

    Energy Technology Data Exchange (ETDEWEB)

    Clinton Lum

    2002-02-04

    The purpose of this Analysis and Model Report (AMR) is to document Rock Properties Model (RPM) 3.1 with regard to input data, model methods, assumptions, uncertainties and limitations of model results, and qualification status of the model. The report also documents the differences between the current and previous versions and validation of the model. The rock properties models are intended principally for use as input to numerical physical-process modeling, such as of ground-water flow and/or radionuclide transport. The constraints, caveats, and limitations associated with this model are discussed in the appropriate text sections that follow. This work was conducted in accordance with the following planning documents: WA-0344, ''3-D Rock Properties Modeling for FY 1998'' (SNL 1997, WA-0358), ''3-D Rock Properties Modeling for FY 1999'' (SNL 1999), and the technical development plan, Rock Properties Model Version 3.1, (CRWMS M&O 1999c). The Interim Change Notice (ICNs), ICN 02 and ICN 03, of this AMR were prepared as part of activities being conducted under the Technical Work Plan, TWP-NBS-GS-000003, ''Technical Work Plan for the Integrated Site Model, Process Model Report, Revision 01'' (CRWMS M&O 2000b). The purpose of ICN 03 is to record changes in data input status due to data qualification and verification activities. These work plans describe the scope, objectives, tasks, methodology, and implementing procedures for model construction. The constraints, caveats, and limitations associated with this model are discussed in the appropriate text sections that follow. The work scope for this activity consists of the following: (1) Conversion of the input data (laboratory measured porosity data, x-ray diffraction mineralogy, petrophysical calculations of bound water, and petrophysical calculations of porosity) for each borehole into stratigraphic coordinates; (2) Re-sampling and merging of data sets; (3

  14. Model Reduction of Nonlinear Fire Dynamics Models

    OpenAIRE

    Lattimer, Alan Martin

    2016-01-01

    Due to the complexity, multi-scale, and multi-physics nature of the mathematical models for fires, current numerical models require too much computational effort to be useful in design and real-time decision making, especially when dealing with fires over large domains. To reduce the computational time while retaining the complexity of the domain and physics, our research has focused on several reduced-order modeling techniques. Our contributions are improving wildland fire reduced-order mod...

  15. Assessing the outstanding 2003 fire events in Portugal with a Regional Climate Model

    Science.gov (United States)

    Trigo, Ricardo; Jerez, Sonia; Camara, Carlos; Montávez, Juan Pedro

    2013-04-01

    The heatwave that struck western Iberia in the early days of August 2003 was characterized by record high values of both maximum (47.3°C) and minimum (30.6°c) temperatures in Portugal, associated with extremely low humidity levels and relatively intense wind speed (Trigo et al., 2006). These conditions triggered the most devastating sequence of large fires ever registered in Portugal. The estimated total burnt area was about 450.000 ha, including 280.000 ha of forest (Pereira et al., 2011). The outstanding total burnt area value corresponds to roughly 5% of the Portuguese territory, and represents approximately twice the previous maximum observed in 1998 (~220.000 ha), and about four times the long-term average observed between 1980 and 2004. Here we characterise this unusual episode using meteorological fields obtained from both observations and a regional climate model. In this work we use the longest (49-years) high-resolution regional climate simulation available driven by reanalysis data spanning from 1959 to 2007 and covering the entire Iberian Peninsula. This long run was obtained using the MM5 model with a spatial resolution of 10 km. Using this high spatial and temporal resolution we have computed the Canadian Fire Weather Index (FWI) System to produce hourly values of fire risk. The FWI System consists of six components that account for the effects of fuel moisture and wind on fire behaviour (van Wagner, 1987). We show the temporal evolution of high resolution patterns for several fire related variables during the most important days for triggering new fires (the first week of August 2003). Besides the absolute value of Tmax, Tmin, wind (speed and direction), relative humidity and FWI we also evaluate the corresponding anomalies of these fields, obtained after removing the long-term smoothed daily climatology. Pereira M.G., Malamude B.D., Trigo R.M., Alves P.I. (2011) "The History and Characteristics of the 1980-2005 Portuguese Rural Fire Database

  16. Better models are more effectively connected models

    Science.gov (United States)

    Nunes, João Pedro; Bielders, Charles; Darboux, Frederic; Fiener, Peter; Finger, David; Turnbull-Lloyd, Laura; Wainwright, John

    2016-04-01

    The concept of hydrologic and geomorphologic connectivity describes the processes and pathways which link sources (e.g. rainfall, snow and ice melt, springs, eroded areas and barren lands) to accumulation areas (e.g. foot slopes, streams, aquifers, reservoirs), and the spatial variations thereof. There are many examples of hydrological and sediment connectivity on a watershed scale; in consequence, a process-based understanding of connectivity is crucial to help managers understand their systems and adopt adequate measures for flood prevention, pollution mitigation and soil protection, among others. Modelling is often used as a tool to understand and predict fluxes within a catchment by complementing observations with model results. Catchment models should therefore be able to reproduce the linkages, and thus the connectivity of water and sediment fluxes within the systems under simulation. In modelling, a high level of spatial and temporal detail is desirable to ensure taking into account a maximum number of components, which then enables connectivity to emerge from the simulated structures and functions. However, computational constraints and, in many cases, lack of data prevent the representation of all relevant processes and spatial/temporal variability in most models. In most cases, therefore, the level of detail selected for modelling is too coarse to represent the system in a way in which connectivity can emerge; a problem which can be circumvented by representing fine-scale structures and processes within coarser scale models using a variety of approaches. This poster focuses on the results of ongoing discussions on modelling connectivity held during several workshops within COST Action Connecteur. It assesses the current state of the art of incorporating the concept of connectivity in hydrological and sediment models, as well as the attitudes of modellers towards this issue. The discussion will focus on the different approaches through which connectivity

  17. Multiple Model Approaches to Modelling and Control,

    DEFF Research Database (Denmark)

    on the ease with which prior knowledge can be incorporated. It is interesting to note that researchers in Control Theory, Neural Networks,Statistics, Artificial Intelligence and Fuzzy Logic have more or less independently developed very similar modelling methods, calling them Local ModelNetworks, Operating...... of introduction of existing knowledge, as well as the ease of model interpretation. This book attempts to outlinemuch of the common ground between the various approaches, encouraging the transfer of ideas.Recent progress in algorithms and analysis is presented, with constructive algorithms for automated model...

  18. Integrity modelling of tropospheric delay models

    Science.gov (United States)

    Rózsa, Szabolcs; Bastiaan Ober, Pieter; Mile, Máté; Ambrus, Bence; Juni, Ildikó

    2017-04-01

    The effect of the neutral atmosphere on signal propagation is routinely estimated by various tropospheric delay models in satellite navigation. Although numerous studies can be found in the literature investigating the accuracy of these models, for safety-of-life applications it is crucial to study and model the worst case performance of these models using very low recurrence frequencies. The main objective of the INTegrity of TROpospheric models (INTRO) project funded by the ESA PECS programme is to establish a model (or models) of the residual error of existing tropospheric delay models for safety-of-life applications. Such models are required to overbound rare tropospheric delays and should thus include the tails of the error distributions. Their use should lead to safe error bounds on the user position and should allow computation of protection levels for the horizontal and vertical position errors. The current tropospheric model from the RTCA SBAS Minimal Operational Standards has an associated residual error that equals 0.12 meters in the vertical direction. This value is derived by simply extrapolating the observed distribution of the residuals into the tail (where no data is present) and then taking the point where the cumulative distribution has an exceedance level would be 10-7.While the resulting standard deviation is much higher than the estimated standard variance that best fits the data (0.05 meters), it surely is conservative for most applications. In the context of the INTRO project some widely used and newly developed tropospheric delay models (e.g. RTCA MOPS, ESA GALTROPO and GPT2W) were tested using 16 years of daily ERA-INTERIM Reanalysis numerical weather model data and the raytracing technique. The results showed that the performance of some of the widely applied models have a clear seasonal dependency and it is also affected by a geographical position. In order to provide a more realistic, but still conservative estimation of the residual

  19. Numerical Modelling of Streams

    DEFF Research Database (Denmark)

    Vestergaard, Kristian

    In recent years there has been a sharp increase in the use of numerical water quality models. Numeric water quality modeling can be divided into three steps: Hydrodynamic modeling for the determination of stream flow and water levels. Modelling of transport and dispersion of a conservative...

  20. Graphical Models with R

    DEFF Research Database (Denmark)

    Højsgaard, Søren; Edwards, David; Lauritzen, Steffen

    , the book provides examples of how more advanced aspects of graphical modeling can be represented and handled within R. Topics covered in the seven chapters include graphical models for contingency tables, Gaussian and mixed graphical models, Bayesian networks and modeling high dimensional data...

  1. Dynamic Latent Classification Model

    DEFF Research Database (Denmark)

    Zhong, Shengtong; Martínez, Ana M.; Nielsen, Thomas Dyhre

    as possible. Motivated by this problem setting, we propose a generative model for dynamic classification in continuous domains. At each time point the model can be seen as combining a naive Bayes model with a mixture of factor analyzers (FA). The latent variables of the FA are used to capture the dynamics...... in the process as well as modeling dependences between attributes....

  2. HRM: HII Region Models

    Science.gov (United States)

    Wenger, Trey V.; Kepley, Amanda K.; Balser, Dana S.

    2017-07-01

    HII Region Models fits HII region models to observed radio recombination line and radio continuum data. The algorithm includes the calculations of departure coefficients to correct for non-LTE effects. HII Region Models has been used to model star formation in the nucleus of IC 342.

  3. Multilevel IRT Model Assessment

    NARCIS (Netherlands)

    Fox, Jean-Paul; Ark, L. Andries; Croon, Marcel A.

    2005-01-01

    Modelling complex cognitive and psychological outcomes in, for example, educational assessment led to the development of generalized item response theory (IRT) models. A class of models was developed to solve practical and challenging educational problems by generalizing the basic IRT models. An IRT

  4. Models for Dynamic Applications

    DEFF Research Database (Denmark)

    2011-01-01

    be applied to formulate, analyse and solve these dynamic problems and how in the case of the fuel cell problem the model consists of coupledmeso and micro scale models. It is shown how data flows are handled between the models and how the solution is obtained within the modelling environment....

  5. Multivariate GARCH models

    DEFF Research Database (Denmark)

    Silvennoinen, Annastiina; Teräsvirta, Timo

    This article contains a review of multivariate GARCH models. Most common GARCH models are presented and their properties considered. This also includes nonparametric and semiparametric models. Existing specification and misspecification tests are discussed. Finally, there is an empirical example...... in which several multivariate GARCH models are fitted to the same data set and the results compared....

  6. The Model Confidence Set

    DEFF Research Database (Denmark)

    Hansen, Peter Reinhard; Lunde, Asger; Nason, James M.

    The paper introduces the model confidence set (MCS) and applies it to the selection of models. A MCS is a set of models that is constructed such that it will contain the best model with a given level of confidence. The MCS is in this sense analogous to a confidence interval for a parameter. The M...

  7. Modelling Railway Interlocking Systems

    DEFF Research Database (Denmark)

    Lindegaard, Morten Peter; Viuf, P.; Haxthausen, Anne Elisabeth

    2000-01-01

    In this report we present a model of interlocking systems, and describe how the model may be validated by simulation. Station topologies are modelled by graphs in which the nodes denote track segments, and the edges denote connectivity for train traÆc. Points and signals are modelled by annotatio...

  8. AIDS Epidemiological models

    Science.gov (United States)

    Rahmani, Fouad Lazhar

    2010-11-01

    The aim of this paper is to present mathematical modelling of the spread of infection in the context of the transmission of the human immunodeficiency virus (HIV) and the acquired immune deficiency syndrome (AIDS). These models are based in part on the models suggested in the field of th AIDS mathematical modelling as reported by ISHAM [6].

  9. Multivariate GARCH models

    DEFF Research Database (Denmark)

    Silvennoinen, Annastiina; Teräsvirta, Timo

    This article contains a review of multivariate GARCH models. Most common GARCH models are presented and their properties considered. This also includes nonparametric and semiparametric models. Existing specification and misspecification tests are discussed. Finally, there is an empirical example...... in which several multivariate GARCH models are fitted to the same data set and the results compared....

  10. Multilevel IRT Model Assessment

    NARCIS (Netherlands)

    Fox, Gerardus J.A.; Ark, L. Andries; Croon, Marcel A.

    2005-01-01

    Modelling complex cognitive and psychological outcomes in, for example, educational assessment led to the development of generalized item response theory (IRT) models. A class of models was developed to solve practical and challenging educational problems by generalizing the basic IRT models. An IRT

  11. Biomass Scenario Model

    Energy Technology Data Exchange (ETDEWEB)

    2015-09-01

    The Biomass Scenario Model (BSM) is a unique, carefully validated, state-of-the-art dynamic model of the domestic biofuels supply chain which explicitly focuses on policy issues, their feasibility, and potential side effects. It integrates resource availability, physical/technological/economic constraints, behavior, and policy. The model uses a system dynamics simulation (not optimization) to model dynamic interactions across the supply chain.

  12. Lumped-parameter models

    Energy Technology Data Exchange (ETDEWEB)

    Ibsen, Lars Bo; Liingaard, M.

    2006-12-15

    A lumped-parameter model represents the frequency dependent soil-structure interaction of a massless foundation placed on or embedded into an unbounded soil domain. In this technical report the steps of establishing a lumped-parameter model are presented. Following sections are included in this report: Static and dynamic formulation, Simple lumped-parameter models and Advanced lumped-parameter models. (au)

  13. Plant development models

    NARCIS (Netherlands)

    Chuine, I.; Garcia de Cortazar-Atauri, I.; Kramer, K.; Hänninen, H.

    2013-01-01

    In this chapter we provide a brief overview of plant phenology modeling, focusing on mechanistic phenological models. After a brief history of plant phenology modeling, we present the different models which have been described in the literature so far and highlight the main differences between them,

  14. Generic Market Models

    NARCIS (Netherlands)

    R. Pietersz (Raoul); M. van Regenmortel

    2005-01-01

    textabstractCurrently, there are two market models for valuation and risk management of interest rate derivatives, the LIBOR and swap market models. In this paper, we introduce arbitrage-free constant maturity swap (CMS) market models and generic market models featuring forward rates that span perio

  15. A Model for Conversation

    DEFF Research Database (Denmark)

    Ayres, Phil

    2012-01-01

    This essay discusses models. It examines what models are, the roles models perform and suggests various intentions that underlie their construction and use. It discusses how models act as a conversational partner, and how they support various forms of conversation within the conversational activity...... of design. Three distinctions are drawn through which to develop this discussion of models in an architectural context. An examination of these distinctions serves to nuance particular characteristics and roles of models, the modelling activity itself and those engaged in it....

  16. Talk about toy models

    Science.gov (United States)

    Luczak, Joshua

    2017-02-01

    Scientific models are frequently discussed in philosophy of science. A great deal of the discussion is centred on approximation, idealisation, and on how these models achieve their representational function. Despite the importance, distinct nature, and high presence of toy models, they have received little attention from philosophers. This paper hopes to remedy this situation. It aims to elevate the status of toy models: by distinguishing them from approximations and idealisations, by highlighting and elaborating on several ways the Kac ring, a simple statistical mechanical model, is used as a toy model, and by explaining why toy models can be used to successfully carry out important work without performing a representational function.

  17. Latent classification models

    DEFF Research Database (Denmark)

    Langseth, Helge; Nielsen, Thomas Dyhre

    2005-01-01

    One of the simplest, and yet most consistently well-performing setof classifiers is the \\NB models. These models rely on twoassumptions: $(i)$ All the attributes used to describe an instanceare conditionally independent given the class of that instance,and $(ii)$ all attributes follow a specific...... parametric family ofdistributions.  In this paper we propose a new set of models forclassification in continuous domains, termed latent classificationmodels. The latent classification model can roughly be seen ascombining the \\NB model with a mixture of factor analyzers,thereby relaxing the assumptions...... classification model, and wedemonstrate empirically that the accuracy of the proposed model issignificantly higher than the accuracy of other probabilisticclassifiers....

  18. Wastewater treatment models

    DEFF Research Database (Denmark)

    Gernaey, Krist; Sin, Gürkan

    2011-01-01

    The state-of-the-art level reached in modeling wastewater treatment plants (WWTPs) is reported. For suspended growth systems, WWTP models have evolved from simple description of biological removal of organic carbon and nitrogen in aeration tanks (ASM1 in 1987) to more advanced levels including...... of WWTP modeling by linking the wastewater treatment line with the sludge handling line in one modeling platform. Application of WWTP models is currently rather time consuming and thus expensive due to the high model complexity, and requires a great deal of process knowledge and modeling expertise...

  19. Wastewater Treatment Models

    DEFF Research Database (Denmark)

    Gernaey, Krist; Sin, Gürkan

    2008-01-01

    The state-of-the-art level reached in modeling wastewater treatment plants (WWTPs) is reported. For suspended growth systems, WWTP models have evolved from simple description of biological removal of organic carbon and nitrogen in aeration tanks (ASM1 in 1987) to more advanced levels including...... the practice of WWTP modeling by linking the wastewater treatment line with the sludge handling line in one modeling platform. Application of WWTP models is currently rather time consuming and thus expensive due to the high model complexity, and requires a great deal of process knowledge and modeling expertise...

  20. The Hospitable Meal Model

    DEFF Research Database (Denmark)

    Justesen, Lise; Overgaard, Svend Skafte

    2017-01-01

    This article presents an analytical model that aims to conceptualize how meal experiences are framed when taking into account a dynamic understanding of hospitality: the meal model is named The Hospitable Meal Model. The idea behind The Hospitable Meal Model is to present a conceptual model...... that can serve as a frame for developing hospitable meal competencies among professionals working within the area of institutional foodservices as well as a conceptual model for analysing meal experiences. The Hospitable Meal Model transcends and transforms existing meal models by presenting a more open......-ended approach towards meal experiences. The underlying purpose of The Hospitable Meal Model is to provide the basis for creating value for the individuals involved in institutional meal services. The Hospitable Meal Model was developed on the basis of an empirical study on hospital meal experiences explored...

  1. Protein Models Comparator

    CERN Document Server

    Widera, Paweł

    2011-01-01

    The process of comparison of computer generated protein structural models is an important element of protein structure prediction. It has many uses including model quality evaluation, selection of the final models from a large set of candidates or optimisation of parameters of energy functions used in template free modelling and refinement. Although many protein comparison methods are available online on numerous web servers, their ability to handle a large scale model comparison is often very limited. Most of the servers offer only a single pairwise structural comparison, and they usually do not provide a model-specific comparison with a fixed alignment between the models. To bridge the gap between the protein and model structure comparison we have developed the Protein Models Comparator (pm-cmp). To be able to deliver the scalability on demand and handle large comparison experiments the pm-cmp was implemented "in the cloud". Protein Models Comparator is a scalable web application for a fast distributed comp...

  2. Nonuniform Markov models

    CERN Document Server

    Ristad, E S; Ristad, Eric Sven; Thomas, Robert G.

    1996-01-01

    A statistical language model assigns probability to strings of arbitrary length. Unfortunately, it is not possible to gather reliable statistics on strings of arbitrary length from a finite corpus. Therefore, a statistical language model must decide that each symbol in a string depends on at most a small, finite number of other symbols in the string. In this report we propose a new way to model conditional independence in Markov models. The central feature of our nonuniform Markov model is that it makes predictions of varying lengths using contexts of varying lengths. Experiments on the Wall Street Journal reveal that the nonuniform model performs slightly better than the classic interpolated Markov model. This result is somewhat remarkable because both models contain identical numbers of parameters whose values are estimated in a similar manner. The only difference between the two models is how they combine the statistics of longer and shorter strings. Keywords: nonuniform Markov model, interpolated Markov m...

  3. Lumped Thermal Household Model

    DEFF Research Database (Denmark)

    Biegel, Benjamin; Andersen, Palle; Stoustrup, Jakob

    2013-01-01

    a lumped model approach as an alternative to the individual models. In the lumped model, the portfolio is seen as baseline consumption superimposed with an ideal storage of limited power and energy capacity. The benefit of such a lumped model is that the computational effort of flexibility optimization......In this paper we discuss two different approaches to model the flexible power consumption of heat pump heated households: individual household modeling and lumped modeling. We illustrate that a benefit of individual modeling is that we can overview and optimize the complete flexibility of a heat...... pump portfolio. Following, we illustrate two disadvantages of individual models, namely that it requires much computational effort to optimize over a large portfolio, and second that it is difficult to accurately model the houses in certain time periods due to local disturbances. Finally, we propose...

  4. Calibrated Properties Model

    Energy Technology Data Exchange (ETDEWEB)

    C. Ahlers; H. Liu

    2000-03-12

    The purpose of this Analysis/Model Report (AMR) is to document the Calibrated Properties Model that provides calibrated parameter sets for unsaturated zone (UZ) flow and transport process models for the Yucca Mountain Site Characterization Project (YMP). This work was performed in accordance with the ''AMR Development Plan for U0035 Calibrated Properties Model REV00. These calibrated property sets include matrix and fracture parameters for the UZ Flow and Transport Model (UZ Model), drift seepage models, drift-scale and mountain-scale coupled-processes models, and Total System Performance Assessment (TSPA) models as well as Performance Assessment (PA) and other participating national laboratories and government agencies. These process models provide the necessary framework to test conceptual hypotheses of flow and transport at different scales and predict flow and transport behavior under a variety of climatic and thermal-loading conditions.

  5. Introduction to Adjoint Models

    Science.gov (United States)

    Errico, Ronald M.

    2015-01-01

    In this lecture, some fundamentals of adjoint models will be described. This includes a basic derivation of tangent linear and corresponding adjoint models from a parent nonlinear model, the interpretation of adjoint-derived sensitivity fields, a description of methods of automatic differentiation, and the use of adjoint models to solve various optimization problems, including singular vectors. Concluding remarks will attempt to correct common misconceptions about adjoint models and their utilization.

  6. Modeling cholera outbreaks

    OpenAIRE

    Chao, Dennis L.; Ira M Longini; Morris, J. Glenn

    2014-01-01

    Mathematical modeling can be a valuable tool for studying infectious disease outbreak dynamics and simulating the effects of possible interventions. Here, we describe approaches to modeling cholera outbreaks and how models have been applied to explore intervention strategies, particularly in Haiti. Mathematical models can play an important role in formulating and evaluating complex cholera outbreak response options. Major challenges to cholera modeling are insufficient data for calibrating mo...

  7. Business Model Visualization

    OpenAIRE

    Zagorsek, Branislav

    2013-01-01

    Business model describes the company’s most important activities, proposed value, and the compensation for the value. Business model visualization enables to simply and systematically capture and describe the most important components of the business model while the standardization of the concept allows the comparison between companies. There are several possibilities how to visualize the model. The aim of this paper is to describe the options for business model visualization and business mod...

  8. Diffeomorphic Statistical Deformation Models

    DEFF Research Database (Denmark)

    Hansen, Michael Sass; Hansen, Mads/Fogtman; Larsen, Rasmus

    2007-01-01

    In this paper we present a new method for constructing diffeomorphic statistical deformation models in arbitrary dimensional images with a nonlinear generative model and a linear parameter space. Our deformation model is a modified version of the diffeomorphic model introduced by Cootes et al. Th...... with ground truth in form of manual expert annotations, and compared to Cootes's model. We anticipate applications in unconstrained diffeomorphic synthesis of images, e.g. for tracking, segmentation, registration or classification purposes....

  9. Dimension of linear models

    DEFF Research Database (Denmark)

    Høskuldsson, Agnar

    1996-01-01

    Determination of the proper dimension of a given linear model is one of the most important tasks in the applied modeling work. We consider here eight criteria that can be used to determine the dimension of the model, or equivalently, the number of components to use in the model. Four...... the basic problems in determining the dimension of linear models. Then each of the eight measures are treated. The results are illustrated by examples....

  10. Modeling cholera outbreaks

    OpenAIRE

    Dennis L Chao; Longini, Ira M.; Morris, J. Glenn

    2014-01-01

    Mathematical modeling can be a valuable tool for studying infectious disease outbreak dynamics and simulating the effects of possible interventions. Here, we describe approaches to modeling cholera outbreaks and how models have been applied to explore intervention strategies, particularly in Haiti. Mathematical models can play an important role in formulating and evaluating complex cholera outbreak response options. Major challenges to cholera modeling are insufficient data for calibrating mo...

  11. Multiple Model Approaches to Modelling and Control,

    DEFF Research Database (Denmark)

    Why Multiple Models?This book presents a variety of approaches which produce complex models or controllers by piecing together a number of simpler subsystems. Thisdivide-and-conquer strategy is a long-standing and general way of copingwith complexity in engineering systems, nature and human probl...

  12. Model Checking of Boolean Process Models

    CERN Document Server

    Schneider, Christoph

    2011-01-01

    In the field of Business Process Management formal models for the control flow of business processes have been designed since more than 15 years. Which methods are best suited to verify the bulk of these models? The first step is to select a formal language which fixes the semantics of the models. We adopt the language of Boolean systems as reference language for Boolean process models. Boolean systems form a simple subclass of coloured Petri nets. Their characteristics are low tokens to model explicitly states with a subsequent skipping of activations and arbitrary logical rules of type AND, XOR, OR etc. to model the split and join of the control flow. We apply model checking as a verification method for the safeness and liveness of Boolean systems. Model checking of Boolean systems uses the elementary theory of propositional logic, no modal operators are needed. Our verification builds on a finite complete prefix of a certain T-system attached to the Boolean system. It splits the processes of the Boolean sy...

  13. Validation and sensitivity study for the MedCORDEX domain and the Carpathian Region using RegCM4.3

    Science.gov (United States)

    Pongracz, Rita; Pieczka, Ildiko; Andre, Karolina; Bartholy, Judit

    2015-04-01

    In the framework of the Med-CORDEX international initiative our research group is participating with the specific aim of contributing to the complex regional climate modelling database with RegCM4.3 experiments at 50 km horizontal resolution using the mosaic-type subgridding option in order to take into account subgrid processes. For this purpose, we used ERA-Interim data (1981-2010) and HadGEM2 global model outputs (1951-2005) as initial and lateral boundary conditions (ICBC) for the entire MED-44 CORDEX area covering the extended Mediterranean region of Europe. The 50-km resolution RegCM-outputs serve as an ICBC input for further downscaling using 10 km as a horizontal resolution for a smaller domain covering Central Europe with special focus on the Carpathian Region. In order to quantify the impact of the use of different parameterization schemes on regional climate model outputs, hindcast experiments are completed applying the RegCM4.3 model to the Carpathian Region and its surroundings at 10 km horizontal resolution with three different cumulus convection schemes (i.e., Kuo, Emanuel, and Grell schemes with different closure methods). Besides, sensitivity of outputs for subgrid-scale processes is also studied by activating the subgrid Biosphere-Atmosphere Transfer Scheme (BATS) model within other RegCM experiments. RegCM simulation results are sensitive to the driving data since the completed experiments with ERA-Interim and HadGEM2-driven 50-km outputs as ICBC result in different bias patterns. However, when the same driving data are used with different specific set-ups, the simulation results look quite similar. To some extent RegCM is able to reduce the errors inherited from the global datasets. Our validation results for temperature and precipitation suggest that for the Carpathian Region the overall best performance is achieved when using the mixed Grell-Emanuel scheme together with Fritsch & Chappell closure. Moreover, turning the subgrid model on

  14. Photochemical model evaluation of the surface ozone impact of a power plant in a heavily industrialized area of southwestern Spain.

    Science.gov (United States)

    Castell, N; Mantilla, E; Salvador, R; Stein, A F; Millán, M

    2010-01-01

    The characterization and evaluation of the impact that an industry is likely to have on the surrounding ozone levels is one of many problems confronting air quality managers and should be taken into consideration when authorizing its installation. The correct management of an environment, in terms of monitoring existing industries and planning new activities, requires adequate knowledge of the processes sustained by the industrial emissions therein. This paper explores the improvements in air quality management arising from taking into account the uncertainties involved in the photochemical modeling of the impact of an industry on surface ozone levels. For this, we evaluate the impact on ozone levels of a power plant located in an industrial area of southwestern Spain (Huelva). The evaluation takes into account the effects of both emissions' uncertainty and the non-linear chemistry between ozone and its precursors, thus providing a probable range of increase over the normative values (hourly and 8-hourly maximums) defined in the European Directive. The proposed methodology is easily applicable by air quality managers. Advanced modeling techniques were used for the power plant assessment, MM5 atmospheric modeling system, and air quality model CAMx. The results from meteorology and ozone forecasts have shown acceptable agreement with the observations. The spatial distribution of the impact is found to be strongly determined by mesoscale meteorological processes, which are reinforced by the local orography; there is also a marked temporal evolution. The industrial plume is observed to induce a decrease (or maintenance) of the ozone levels near the emission source (0-10km), and an increase in the ozone concentrations farther away (with maximums between 10 and 50km). In fact, in the meteorological episodes with a predominance of local breeze circulations, impacts have been detected at distances of more than 100km from the emission source. Sensitivity of the power plant

  15. Source apportionment of PM2.5 in top polluted cities in Hebei, China using the CMAQ model

    Science.gov (United States)

    Wang, Litao; Wei, Zhe; Wei, Wei; Fu, Joshua S.; Meng, Chenchen; Ma, Simeng

    2015-12-01

    Hebei has been recognized as one of the most polluted provinces in China, characterized by extremely high concentrations of fine particulate matter (PM2.5) in many of its cities, especially those located in the southern area of the province and highly potentially northward transported to Beijing. Source apportionment of PM2.5 is the basis and prerequisite of an effective control strategy. In this study, the Mesoscale Modeling System Generation 5 (MM5) and the Models-3/Community Multiscale Air Quality (CMAQ) modeling system are applied to East Asia and North China at 36- and 12-km horizontal grid resolutions, and the source apportionment of PM2.5 in the three top polluted cities in Hebei, i.e., Shijiazhuang, Xingtai, and Handan, is performed using the Brute-Force method. It is concluded that the regional source contributions to PM2.5 are 27.9% in Shijiazhuang, 46.6% in Xingtai, and 40.4% in Handan. The major local contributors are industrial, domestic and agricultural sources in all the three cities with the contributions of 39.8%, 15.8%, and 10.6% in Shijiazhuang, 30.5%, 13.6%, and 6.9% in Xingtai, 35.9%, 13.5%, and 6.2% in Handan, respectively. As to the secondary aerosols of sulfate (SO42-), nitrate (NO3-), and ammonium (NH4+) in PM2.5, which are important chemical species in PM2.5 (about 30-40% in PM2.5) and cannot be further apportioned by receptor models, the regional source contributions to the total concentrations of SO42-, NO3-, and NH4+ are 40.9%, 62.0%, and 59.1% in Shijiazhuang, Xingtai, and Handan, respectively. The local industrial, domestic and agricultural contributions to those are 23.7%, 6.6%, and 29.8% in total in Shijiazhuang, 17.5%, 5.0%, and 17.7% in Xingtai, and 20.6%, 4.8%, and 17.8% in Handan, respectively. The regional joint controls of air pollution are more important in Xingtai and Handan than in Shijiazhuang, and the emission controls of agricultural sources need to be further considered in the future policy.

  16. Coupling X-band dual-polarized mini-radars and hydro-meteorological forecast models: the HYDRORAD project

    Science.gov (United States)

    Picciotti, E.; Marzano, F. S.; Anagnostou, E. N.; Kalogiros, J.; Fessas, Y.; Volpi, A.; Cazac, V.; Pace, R.; Cinque, G.; Bernardini, L.; De Sanctis, K.; Di Fabio, S.; Montopoli, M.; Anagnostou, M. N.; Telleschi, A.; Dimitriou, E.; Stella, J.

    2013-05-01

    Hydro-meteorological hazards like convective outbreaks leading to torrential rain and floods are among the most critical environmental issues world-wide. In that context weather radar observations have proven to be very useful in providing information on the spatial distribution of rainfall that can support early warning of floods. However, quantitative precipitation estimation by radar is subjected to many limitations and uncertainties. The use of dual-polarization at high frequency (i.e. X-band) has proven particularly useful for mitigating some of the limitation of operational systems, by exploiting the benefit of easiness to transport and deploy and the high spatial and temporal resolution achievable at small antenna sizes. New developments on X-band dual-polarization technology in recent years have received the interest of scientific and operational communities in these systems. New enterprises are focusing on the advancement of cost-efficient mini-radar network technology, based on high-frequency (mainly X-band) and low-power weather radar systems for weather monitoring and hydro-meteorological forecasting. Within the above context, the main objective of the HYDRORAD project was the development of an innovative integrated decision support tool for weather monitoring and hydro-meteorological applications. The integrated system tool is based on a polarimetric X-band mini-radar network which is the core of the decision support tool, a novel radar products generator and a hydro-meteorological forecast modelling system that ingests mini-radar rainfall products to forecast precipitation and floods. The radar products generator includes algorithms for attenuation correction, hydrometeor classification, a vertical profile reflectivity correction, a new polarimetric rainfall estimators developed for mini-radar observations, and short-term nowcasting of convective cells. The hydro-meteorological modelling system includes the Mesoscale Model 5 (MM5) and the Army Corps

  17. Coupling X-band dual-polarized mini-radars and hydro-meteorological forecast models: the HYDRORAD project

    Directory of Open Access Journals (Sweden)

    E. Picciotti

    2013-05-01

    (MM5 and the Army Corps of Engineers Hydrologic Engineering Center hydrologic and hydraulic modelling chain. The characteristics of this tool make it ideal to support flood monitoring and forecasting within urban environment and small-scale basins. Preliminary results, carried out during a field campaign in Moldova, showed that the mini-radar based hydro-meteorological forecasting system can constitute a suitable solution for local flood warning and civil flood protection applications.

  18. Downscaling seasonal to centennial simulations on distributed computing infrastructures using WRF model. The WRF4G project

    Science.gov (United States)

    Cofino, A. S.; Fernández Quiruelas, V.; Blanco Real, J. C.; García Díez, M.; Fernández, J.

    2013-12-01

    Nowadays Grid Computing is powerful computational tool which is ready to be used for scientific community in different areas (such as biomedicine, astrophysics, climate, etc.). However, the use of this distributed computing infrastructures (DCI) is not yet common practice in climate research, and only a few teams and applications in this area take advantage of this infrastructure. Thus, the WRF4G project objective is to popularize the use of this technology in the atmospheric sciences area. In order to achieve this objective, one of the most used applications has been taken (WRF; a limited- area model, successor of the MM5 model), that has a user community formed by more than 8000 researchers worldwide. This community develop its research activity on different areas and could benefit from the advantages of Grid resources (case study simulations, regional hind-cast/forecast, sensitivity studies, etc.). The WRF model is used by many groups, in the climate research community, to carry on downscaling simulations. Therefore this community will also benefit. However, Grid infrastructures have some drawbacks for the execution of applications that make an intensive use of CPU and memory for a long period of time. This makes necessary to develop a specific framework (middleware). This middleware encapsulates the application and provides appropriate services for the monitoring and management of the simulations and the data. Thus,another objective of theWRF4G project consists on the development of a generic adaptation of WRF to DCIs. It should simplify the access to the DCIs for the researchers, and also to free them from the technical and computational aspects of the use of theses DCI. Finally, in order to demonstrate the ability of WRF4G solving actual scientific challenges with interest and relevance on the climate science (implying a high computational cost) we will shown results from different kind of downscaling experiments, like ERA-Interim re-analysis, CMIP5 models

  19. Pavement Aging Model by Response Surface Modeling

    Directory of Open Access Journals (Sweden)

    Manzano-Ramírez A.

    2011-10-01

    Full Text Available In this work, surface course aging was modeled by Response Surface Methodology (RSM. The Marshall specimens were placed in a conventional oven for time and temperature conditions established on the basis of the environment factors of the region where the surface course is constructed by AC-20 from the Ing. Antonio M. Amor refinery. Volatilized material (VM, load resistance increment (ΔL and flow resistance increment (ΔF models were developed by the RSM. Cylindrical specimens with real aging were extracted from the surface course pilot to evaluate the error of the models. The VM model was adequate, in contrast (ΔL and (ΔF models were almost adequate with an error of 20 %, that was associated with the other environmental factors, which were not considered at the beginning of the research.

  20. Quantitative evaluation of patient setup uncertainty of stereotactic radiotherapy with the frameless 6D ExacTrac system using statistical modeling.

    Science.gov (United States)

    Keeling, Vance; Hossain, Sabbir; Jin, Hosang; Algan, Ozer; Ahmad, Salahuddin; Ali, Imad

    2016-05-08

    The purpose of this study is to evaluate patient setup accuracy and quantify indi-vidual and cumulative positioning uncertainties associated with different hardware and software components of the stereotactic radiotherapy (SRS/SRT) with the frameless 6D ExacTrac system. A statistical model is used to evaluate positioning uncertainties of the different components of SRS/SRT treatment with the Brainlab 6D ExacTrac system using the positioning shifts of 35 patients having cranial lesions. All these patients are immobilized with rigid head-and-neck masks, simu-lated with Brainlab localizer and planned with iPlan treatment planning system. Stereoscopic X-ray images (XC) are acquired and registered to corresponding digitally reconstructed radiographs using bony-anatomy matching to calculate 6D translational and rotational shifts. When the shifts are within tolerance (0.7 mm and 1°), treatment is initiated. Otherwise corrections are applied and additional X-rays (XV) are acquired to verify that patient position is within tolerance. The uncertain-ties from the mask, localizer, IR -frame, X-ray imaging, MV, and kV isocentricity are quantified individually. Mask uncertainty (translational: lateral, longitudinal, vertical; rotational: pitch, roll, yaw) is the largest and varies with patients in the range (-2.07-3.71 mm, -5.82-5.62 mm, -5.84-3.61 mm; -2.10-2.40°, -2.23-2.60°, and -2.7-3.00°) obtained from mean of XC shifts for each patient. Setup uncer-tainty in IR positioning (0.88, 2.12, 1.40 mm, and 0.64°, 0.83°, 0.96°) is extracted from standard deviation of XC. Systematic uncertainties of the frame (0.18, 0.25, -1.27mm, -0.32°, 0.18°, and 0.47°) and localizer (-0.03, -0.01, 0.03mm, and -0.03°, 0.00°, -0.01°) are extracted from means of all XV setups and mean of all XC distributions, respectively. Uncertainties in isocentricity of the MV radiotherapy machine are (0.27, 0.24, 0.34 mm) and kV imager (0.15, -0.4, 0.21 mm). A statisti-cal model is developed to

  1. Model Validation Status Review

    Energy Technology Data Exchange (ETDEWEB)

    E.L. Hardin

    2001-11-28

    The primary objective for the Model Validation Status Review was to perform a one-time evaluation of model validation associated with the analysis/model reports (AMRs) containing model input to total-system performance assessment (TSPA) for the Yucca Mountain site recommendation (SR). This review was performed in response to Corrective Action Request BSC-01-C-01 (Clark 2001, Krisha 2001) pursuant to Quality Assurance review findings of an adverse trend in model validation deficiency. The review findings in this report provide the following information which defines the extent of model validation deficiency and the corrective action needed: (1) AMRs that contain or support models are identified, and conversely, for each model the supporting documentation is identified. (2) The use for each model is determined based on whether the output is used directly for TSPA-SR, or for screening (exclusion) of features, events, and processes (FEPs), and the nature of the model output. (3) Two approaches are used to evaluate the extent to which the validation for each model is compliant with AP-3.10Q (Analyses and Models). The approaches differ in regard to whether model validation is achieved within individual AMRs as originally intended, or whether model validation could be readily achieved by incorporating information from other sources. (4) Recommendations are presented for changes to the AMRs, and additional model development activities or data collection, that will remedy model validation review findings, in support of licensing activities. The Model Validation Status Review emphasized those AMRs that support TSPA-SR (CRWMS M&O 2000bl and 2000bm). A series of workshops and teleconferences was held to discuss and integrate the review findings. The review encompassed 125 AMRs (Table 1) plus certain other supporting documents and data needed to assess model validity. The AMRs were grouped in 21 model areas representing the modeling of processes affecting the natural and

  2. Product and Process Modelling

    DEFF Research Database (Denmark)

    Cameron, Ian T.; Gani, Rafiqul

    This book covers the area of product and process modelling via a case study approach. It addresses a wide range of modelling applications with emphasis on modelling methodology and the subsequent in-depth analysis of mathematical models to gain insight via structural aspects of the models....... These approaches are put into the context of life cycle modelling, where multiscale and multiform modelling is increasingly prevalent in the 21st century. The book commences with a discussion of modern product and process modelling theory and practice followed by a series of case studies drawn from a variety...... to biotechnology applications, food, polymer and human health application areas. The book highlights to important nature of modern product and process modelling in the decision making processes across the life cycle. As such it provides an important resource for students, researchers and industrial practitioners....

  3. Practical Marginalized Multilevel Models.

    Science.gov (United States)

    Griswold, Michael E; Swihart, Bruce J; Caffo, Brian S; Zeger, Scott L

    2013-01-01

    Clustered data analysis is characterized by the need to describe both systematic variation in a mean model and cluster-dependent random variation in an association model. Marginalized multilevel models embrace the robustness and interpretations of a marginal mean model, while retaining the likelihood inference capabilities and flexible dependence structures of a conditional association model. Although there has been increasing recognition of the attractiveness of marginalized multilevel models, there has been a gap in their practical application arising from a lack of readily available estimation procedures. We extend the marginalized multilevel model to allow for nonlinear functions in both the mean and association aspects. We then formulate marginal models through conditional specifications to facilitate estimation with mixed model computational solutions already in place. We illustrate the MMM and approximate MMM approaches on a cerebrovascular deficiency crossover trial using SAS and an epidemiological study on race and visual impairment using R. Datasets, SAS and R code are included as supplemental materials.

  4. Modelling Foundations and Applications

    DEFF Research Database (Denmark)

    This book constitutes the refereed proceedings of the 8th European Conference on Modelling Foundations and Applications, held in Kgs. Lyngby, Denmark, in July 2012. The 20 revised full foundations track papers and 10 revised full applications track papers presented were carefully reviewed...... and selected from 81 submissions. Papers on all aspects of MDE were received, including topics such as architectural modelling and product lines, code generation, domain-specic modeling, metamodeling, model analysis and verication, model management, model transformation and simulation. The breadth of topics...

  5. On Communication Models

    Institute of Scientific and Technical Information of China (English)

    蒋娜; 谢有琪

    2012-01-01

    With the development of human society, the social hub enlarges beyond one community to the extent that the world is deemed as a community as a whole. Communication, therefore, plays an increasingly important role in our daily life. As a consequence, communication model or the definition of which is not so much a definition as a guide in communication. However, some existed communication models are not as practical as it was. This paper tries to make an overall contrast among three communication models Coded Model, Gable Communication Model and Ostensive Inferential Model, to see how they assist people to comprehend verbal and non -verbal communication.

  6. Modeling worldwide highway networks

    Science.gov (United States)

    Villas Boas, Paulino R.; Rodrigues, Francisco A.; da F. Costa, Luciano

    2009-12-01

    This Letter addresses the problem of modeling the highway systems of different countries by using complex networks formalism. More specifically, we compare two traditional geographical models with a modified geometrical network model where paths, rather than edges, are incorporated at each step between the origin and the destination vertices. Optimal configurations of parameters are obtained for each model and used for the comparison. The highway networks of Australia, Brazil, India, and Romania are considered and shown to be properly modeled by the modified geographical model.

  7. THE IMPROVED XINANJIANG MODEL

    Institute of Scientific and Technical Information of China (English)

    LI Zhi-jia; YAO Cheng; KONG Xiang-guang

    2005-01-01

    To improve the Xinanjiang model, the runoff generating from infiltration-excess is added to the model.The another 6 parameters are added to Xinanjiang model.In principle, the improved Xinanjiang model can be used to simulate runoff in the humid, semi-humid and also semi-arid regions.The application in Yi River shows the improved Xinanjiang model could forecast discharge with higher accuracy and can satisfy the practical requirements.It also shows that the improved model is reasonable.

  8. Microsoft tabular modeling cookbook

    CERN Document Server

    Braak, Paul te

    2013-01-01

    This book follows a cookbook style with recipes explaining the steps for developing analytic data using Business Intelligence Semantic Models.This book is designed for developers who wish to develop powerful and dynamic models for users as well as those who are responsible for the administration of models in corporate environments. It is also targeted at analysts and users of Excel who wish to advance their knowledge of Excel through the development of tabular models or who wish to analyze data through tabular modeling techniques. We assume no prior knowledge of tabular modeling

  9. Five models of capitalism

    Directory of Open Access Journals (Sweden)

    Luiz Carlos Bresser-Pereira

    2012-03-01

    Full Text Available Besides analyzing capitalist societies historically and thinking of them in terms of phases or stages, we may compare different models or varieties of capitalism. In this paper I survey the literature on this subject, and distinguish the classification that has a production or business approach from those that use a mainly political criterion. I identify five forms of capitalism: among the rich countries, the liberal democratic or Anglo-Saxon model, the social or European model, and the endogenous social integration or Japanese model; among developing countries, I distinguish the Asian developmental model from the liberal-dependent model that characterizes most other developing countries, including Brazil.

  10. Holographic twin Higgs model.

    Science.gov (United States)

    Geller, Michael; Telem, Ofri

    2015-05-15

    We present the first realization of a "twin Higgs" model as a holographic composite Higgs model. Uniquely among composite Higgs models, the Higgs potential is protected by a new standard model (SM) singlet elementary "mirror" sector at the sigma model scale f and not by the composite states at m_{KK}, naturally allowing for m_{KK} beyond the LHC reach. As a result, naturalness in our model cannot be constrained by the LHC, but may be probed by precision Higgs measurements at future lepton colliders, and by direct searches for Kaluza-Klein excitations at a 100 TeV collider.

  11. Energy-consumption modelling

    Energy Technology Data Exchange (ETDEWEB)

    Reiter, E.R.

    1980-01-01

    A highly sophisticated and accurate approach is described to compute on an hourly or daily basis the energy consumption for space heating by individual buildings, urban sectors, and whole cities. The need for models and specifically weather-sensitive models, composite models, and space-heating models are discussed. Development of the Colorado State University Model, based on heat-transfer equations and on a heuristic, adaptive, self-organizing computation learning approach, is described. Results of modeling energy consumption by the city of Minneapolis and Cheyenne are given. Some data on energy consumption in individual buildings are included.

  12. Empirical Model Building Data, Models, and Reality

    CERN Document Server

    Thompson, James R

    2011-01-01

    Praise for the First Edition "This...novel and highly stimulating book, which emphasizes solving real problems...should be widely read. It will have a positive and lasting effect on the teaching of modeling and statistics in general." - Short Book Reviews This new edition features developments and real-world examples that showcase essential empirical modeling techniques Successful empirical model building is founded on the relationship between data and approximate representations of the real systems that generated that data. As a result, it is essential for researchers who construct these m

  13. Develop a Model Component

    Science.gov (United States)

    Ensey, Tyler S.

    2013-01-01

    During my internship at NASA, I was a model developer for Ground Support Equipment (GSE). The purpose of a model developer is to develop and unit test model component libraries (fluid, electrical, gas, etc.). The models are designed to simulate software for GSE (Ground Special Power, Crew Access Arm, Cryo, Fire and Leak Detection System, Environmental Control System (ECS), etc. .) before they are implemented into hardware. These models support verifying local control and remote software for End-Item Software Under Test (SUT). The model simulates the physical behavior (function, state, limits and 110) of each end-item and it's dependencies as defined in the Subsystem Interface Table, Software Requirements & Design Specification (SRDS), Ground Integrated Schematic (GIS), and System Mechanical Schematic.(SMS). The software of each specific model component is simulated through MATLAB's Simulink program. The intensiv model development life cycle is a.s follows: Identify source documents; identify model scope; update schedule; preliminary design review; develop model requirements; update model.. scope; update schedule; detailed design review; create/modify library component; implement library components reference; implement subsystem components; develop a test script; run the test script; develop users guide; send model out for peer review; the model is sent out for verifictionlvalidation; if there is empirical data, a validation data package is generated; if there is not empirical data, a verification package is generated; the test results are then reviewed; and finally, the user. requests accreditation, and a statement of accreditation is prepared. Once each component model is reviewed and approved, they are intertwined together into one integrated model. This integrated model is then tested itself, through a test script and autotest, so that it can be concluded that all models work conjointly, for a single purpose. The component I was assigned, specifically, was a

  14. Biosphere Model Report

    Energy Technology Data Exchange (ETDEWEB)

    D.W. Wu; A.J. Smith

    2004-11-08

    The purpose of this report is to document the biosphere model, the Environmental Radiation Model for Yucca Mountain, Nevada (ERMYN), which describes radionuclide transport processes in the biosphere and associated human exposure that may arise as the result of radionuclide release from the geologic repository at Yucca Mountain. The biosphere model is one of the process models that support the Yucca Mountain Project (YMP) Total System Performance Assessment (TSPA) for the license application (LA), TSPA-LA. The ERMYN provides the capability of performing human radiation dose assessments. This report documents the biosphere model, which includes: (1) Describing the reference biosphere, human receptor, exposure scenarios, and primary radionuclides for each exposure scenario (Section 6.1); (2) Developing a biosphere conceptual model using site-specific features, events, and processes (FEPs) (Section 6.2), the reference biosphere (Section 6.1.1), the human receptor (Section 6.1.2), and approximations (Sections 6.3.1.4 and 6.3.2.4); (3) Building a mathematical model using the biosphere conceptual model (Section 6.3) and published biosphere models (Sections 6.4 and 6.5); (4) Summarizing input parameters for the mathematical model, including the uncertainty associated with input values (Section 6.6); (5) Identifying improvements in the ERMYN compared with the model used in previous biosphere modeling (Section 6.7); (6) Constructing an ERMYN implementation tool (model) based on the biosphere mathematical model using GoldSim stochastic simulation software (Sections 6.8 and 6.9); (7) Verifying the ERMYN by comparing output from the software with hand calculations to ensure that the GoldSim implementation is correct (Section 6.10); (8) Validating the ERMYN by corroborating it with published biosphere models; comparing conceptual models, mathematical models, and numerical results (Section 7).

  15. Major Differences between the Jerome Model and the Horace Model

    Institute of Scientific and Technical Information of China (English)

    朱艳

    2014-01-01

    There are three famous translation models in the field of translation: the Jerome model, the Horace model and the Schleiermacher model. The production and development of the three models have significant influence on the translation. To find the major differences between the two western classical translation theoretical models, we discuss the Jerome model and the Hor-ace model deeply in this paper.

  16. Modelling cointegration in the vector autoregressive model

    DEFF Research Database (Denmark)

    Johansen, Søren

    2000-01-01

    A survey is given of some results obtained for the cointegrated VAR. The Granger representation theorem is discussed and the notions of cointegration and common trends are defined. The statistical model for cointegrated I(1) variables is defined, and it is shown how hypotheses on the cointegrating...... relations can be estimated under suitable identification conditions. The asymptotic theory is briefly mentioned and a few economic applications of the cointegration model are indicated....

  17. Emissions Modeling Clearinghouse

    Data.gov (United States)

    U.S. Environmental Protection Agency — The Emissions Modeling Clearinghouse (EMCH) supports and promotes emissions modeling activities both internal and external to the EPA. Through this site, the EPA...

  18. ASC Champ Orbit Model

    DEFF Research Database (Denmark)

    Riis, Troels; Jørgensen, John Leif

    1999-01-01

    This documents describes a test of the implementation of the ASC orbit model for the Champ satellite.......This documents describes a test of the implementation of the ASC orbit model for the Champ satellite....

  19. World Magnetic Model 2015

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The World Magnetic Model is the standard model used by the U.S. Department of Defense, the U.K. Ministry of Defence, the North Atlantic Treaty Organization (NATO)...

  20. Laboratory of Biological Modeling

    Data.gov (United States)

    Federal Laboratory Consortium — The Laboratory of Biological Modeling is defined by both its methodologies and its areas of application. We use mathematical modeling in many forms and apply it to...

  1. Model comparison in ANOVA.

    Science.gov (United States)

    Rouder, Jeffrey N; Engelhardt, Christopher R; McCabe, Simon; Morey, Richard D

    2016-12-01

    Analysis of variance (ANOVA), the workhorse analysis of experimental designs, consists of F-tests of main effects and interactions. Yet, testing, including traditional ANOVA, has been recently critiqued on a number of theoretical and practical grounds. In light of these critiques, model comparison and model selection serve as an attractive alternative. Model comparison differs from testing in that one can support a null or nested model vis-a-vis a more general alternative by penalizing more flexible models. We argue this ability to support more simple models allows for more nuanced theoretical conclusions than provided by traditional ANOVA F-tests. We provide a model comparison strategy and show how ANOVA models may be reparameterized to better address substantive questions in data analysis.

  2. Graphical Models with R

    DEFF Research Database (Denmark)

    Højsgaard, Søren; Edwards, David; Lauritzen, Steffen

    Graphical models in their modern form have been around since the late 1970s and appear today in many areas of the sciences. Along with the ongoing developments of graphical models, a number of different graphical modeling software programs have been written over the years. In recent years many...... of these software developments have taken place within the R community, either in the form of new packages or by providing an R ingerface to existing software. This book attempts to give the reader a gentle introduction to graphical modeling using R and the main features of some of these packages. In addition......, the book provides examples of how more advanced aspects of graphical modeling can be represented and handled within R. Topics covered in the seven chapters include graphical models for contingency tables, Gaussian and mixed graphical models, Bayesian networks and modeling high dimensional data...

  3. Controlling Modelling Artifacts

    DEFF Research Database (Denmark)

    Smith, Michael James Andrew; Nielson, Flemming; Nielson, Hanne Riis

    2011-01-01

    the possible configurations of the system (for example, by counting the number of components in a certain state). We motivate our methodology with a case study of the LMAC protocol for wireless sensor networks. In particular, we investigate the accuracy of a recently proposed high-level model of LMAC......When analysing the performance of a complex system, we typically build abstract models that are small enough to analyse, but still capture the relevant details of the system. But it is difficult to know whether the model accurately describes the real system, or if its behaviour is due to modelling...... artifacts that were inadvertently introduced. In this paper, we propose a novel methodology to reason about modelling artifacts, given a detailed model and a highlevel (more abstract) model of the same system. By a series of automated abstraction steps, we lift the detailed model to the same state space...

  4. Laboratory of Biological Modeling

    Data.gov (United States)

    Federal Laboratory Consortium — The Laboratory of Biological Modeling is defined by both its methodologies and its areas of application. We use mathematical modeling in many forms and apply it to a...

  5. Modeling EERE deployment programs

    Energy Technology Data Exchange (ETDEWEB)

    Cort, K. A. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Hostick, D. J. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Belzer, D. B. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Livingston, O. V. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States)

    2007-11-01

    The purpose of the project was to identify and characterize the modeling of deployment programs within the EERE Technology Development (TD) programs, address possible improvements to the modeling process, and note gaps in knowledge for future research.

  6. Consistent model driven architecture

    Science.gov (United States)

    Niepostyn, Stanisław J.

    2015-09-01

    The goal of the MDA is to produce software systems from abstract models in a way where human interaction is restricted to a minimum. These abstract models are based on the UML language. However, the semantics of UML models is defined in a natural language. Subsequently the verification of consistency of these diagrams is needed in order to identify errors in requirements at the early stage of the development process. The verification of consistency is difficult due to a semi-formal nature of UML diagrams. We propose automatic verification of consistency of the series of UML diagrams originating from abstract models implemented with our consistency rules. This Consistent Model Driven Architecture approach enables us to generate automatically complete workflow applications from consistent and complete models developed from abstract models (e.g. Business Context Diagram). Therefore, our method can be used to check practicability (feasibility) of software architecture models.

  7. Bounding species distribution models

    Directory of Open Access Journals (Sweden)

    Thomas J. STOHLGREN, Catherine S. JARNEVICH, Wayne E. ESAIAS,Jeffrey T. MORISETTE

    2011-10-01

    Full Text Available Species distribution models are increasing in popularity for mapping suitable habitat for species of management concern. Many investigators now recognize that extrapolations of these models with geographic information systems (GIS might be sensitive to the environmental bounds of the data used in their development, yet there is no recommended best practice for “clamping” model extrapolations. We relied on two commonly used modeling approaches: classification and regression tree (CART and maximum entropy (Maxent models, and we tested a simple alteration of the model extrapolations, bounding extrapolations to the maximum and minimum values of primary environmental predictors, to provide a more realistic map of suitable habitat of hybridized Africanized honey bees in the southwestern United States. Findings suggest that multiple models of bounding, and the most conservative bounding of species distribution models, like those presented here, should probably replace the unbounded or loosely bounded techniques currently used [Current Zoology 57 (5: 642–647, 2011].

  8. CCF model comparison

    Energy Technology Data Exchange (ETDEWEB)

    Pulkkinen, U. [VTT Industrial Systems (Finland)

    2004-04-01

    The report describes a simple comparison of two CCF-models, the ECLM, and the Beta-model. The objective of the comparison is to identify differences in the results of the models by applying the models in some simple test data cases. The comparison focuses mainly on theoretical aspects of the above mentioned CCF-models. The properties of the model parameter estimates in the data cases is also discussed. The practical aspects in using and estimating CCFmodels in real PSA context (e.g. the data interpretation, properties of computer tools, the model documentation) are not discussed in the report. Similarly, the qualitative CCF-analyses needed in using the models are not discussed in the report. (au)

  9. Chip Multithreaded Consistency Model

    Institute of Scientific and Technical Information of China (English)

    Zu-Song Li; Dan-Dan Huan; Wei-Wu Hu; Zhi-Min Tang

    2008-01-01

    Multithreaded technique is the developing trend of high performance processor. Memory consistency model is essential to the correctness, performance and complexity of multithreaded processor. The chip multithreaded consistency model adapting to multithreaded processor is proposed in this paper. The restriction imposed on memory event ordering by chip multithreaded consistency is presented and formalized. With the idea of critical cycle built by Wei-Wu Hu, we prove that the proposed chip multithreaded consistency model satisfies the criterion of correct execution of sequential consistency model. Chip multithreaded consistency model provides a way of achieving high performance compared with sequential consistency model and ensures the compatibility of software that the execution result in multithreaded processor is the same as the execution result in uniprocessor. The implementation strategy of chip multithreaded consistency model in Godson-2 SMT processor is also proposed. Godson-2 SMT processor supports chip multithreaded consistency model correctly by exception scheme based on the sequential memory access queue of each thread.

  10. Models (Part 1).

    Science.gov (United States)

    Callison, Daniel

    2002-01-01

    Defines models and describes information search models that can be helpful to instructional media specialists in meeting users' abilities and information needs. Explains pathfinders and Kuhlthau's information search process, including the pre-writing information search process. (LRW)

  11. Modeling DNA Replication.

    Science.gov (United States)

    Bennett, Joan

    1998-01-01

    Recommends the use of a model of DNA made out of Velcro to help students visualize the steps of DNA replication. Includes a materials list, construction directions, and details of the demonstration using the model parts. (DDR)

  12. Modeling Complex Time Limits

    Directory of Open Access Journals (Sweden)

    Oleg Svatos

    2013-01-01

    Full Text Available In this paper we analyze complexity of time limits we can find especially in regulated processes of public administration. First we review the most popular process modeling languages. There is defined an example scenario based on the current Czech legislature which is then captured in discussed process modeling languages. Analysis shows that the contemporary process modeling languages support capturing of the time limit only partially. This causes troubles to analysts and unnecessary complexity of the models. Upon unsatisfying results of the contemporary process modeling languages we analyze the complexity of the time limits in greater detail and outline lifecycles of a time limit using the multiple dynamic generalizations pattern. As an alternative to the popular process modeling languages there is presented PSD process modeling language, which supports the defined lifecycles of a time limit natively and therefore allows keeping the models simple and easy to understand.

  13. World Magnetic Model 2010

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The World Magnetic Model is the standard model used by the U.S. Department of Defense, the U.K. Ministry of Defence, the North Atlantic Treaty Organization (NATO)...

  14. Bounding Species Distribution Models

    Science.gov (United States)

    Stohlgren, Thomas J.; Jarnevich, Cahterine S.; Morisette, Jeffrey T.; Esaias, Wayne E.

    2011-01-01

    Species distribution models are increasing in popularity for mapping suitable habitat for species of management concern. Many investigators now recognize that extrapolations of these models with geographic information systems (GIS) might be sensitive to the environmental bounds of the data used in their development, yet there is no recommended best practice for "clamping" model extrapolations. We relied on two commonly used modeling approaches: classification and regression tree (CART) and maximum entropy (Maxent) models, and we tested a simple alteration of the model extrapolations, bounding extrapolations to the maximum and minimum values of primary environmental predictors, to provide a more realistic map of suitable habitat of hybridized Africanized honey bees in the southwestern United States. Findings suggest that multiple models of bounding, and the most conservative bounding of species distribution models, like those presented here, should probably replace the unbounded or loosely bounded techniques currently used [Current Zoology 57 (5): 642-647, 2011].

  15. The ATLAS Analysis Model

    CERN Multimedia

    Amir Farbin

    The ATLAS Analysis Model is a continually developing vision of how to reconcile physics analysis requirements with the ATLAS offline software and computing model constraints. In the past year this vision has influenced the evolution of the ATLAS Event Data Model, the Athena software framework, and physics analysis tools. These developments, along with the October Analysis Model Workshop and the planning for CSC analyses have led to a rapid refinement of the ATLAS Analysis Model in the past few months. This article introduces some of the relevant issues and presents the current vision of the future ATLAS Analysis Model. Event Data Model The ATLAS Event Data Model (EDM) consists of several levels of details, each targeted for a specific set of tasks. For example the Event Summary Data (ESD) stores calorimeter cells and tracking system hits thereby permitting many calibration and alignment tasks, but will be only accessible at particular computing sites with potentially large latency. In contrast, the Analysis...

  16. LAT Background Models

    Data.gov (United States)

    National Aeronautics and Space Administration — The Galactic model is a spatial and spectral template. The model for the Galactic diffuse emission was developed using spectral line surveys of HI and CO (as a...

  17. Photovoltaic sources modeling

    CERN Document Server

    Petrone, Giovanni; Spagnuolo, Giovanni

    2016-01-01

    This comprehensive guide surveys all available models for simulating a photovoltaic (PV) generator at different levels of granularity, from cell to system level, in uniform as well as in mismatched conditions. Providing a thorough comparison among the models, engineers have all the elements needed to choose the right PV array model for specific applications or environmental conditions matched with the model of the electronic circuit used to maximize the PV power production.

  18. Toric models of graphs

    CERN Document Server

    Buczyńska, Weronika

    2010-01-01

    We define toric projective model of a trivalent graph as a generalization of a binary symmetric model of a trivalent phylogenetic tree. Generators of the projective coordinate ring of the models of graphs with one cycle are explicitly described. The models of graphs with the same topological invariants are deformation equivalent and share the same Hilbert function. We also provide an algorithm to compute the Hilbert function.

  19. Model of magnetostrictive actuator

    Institute of Scientific and Technical Information of China (English)

    LI Lin; ZHANG Yuan-yuan

    2005-01-01

    The hysteresis of the magnetostrictive actuator was studied. A mathematical model of the hysteresis loop was obtained on the basis of experiment. This model depends on the frequency and the amplitude of the alternating current inputted to the magnetostrictive actuator. Based on the model, the effect of hysteresis on dynamic output of the magnetostrictive actuator was investigated. Then how to consider hysteresis and establish a dynamic model of a magnetostrictive actuator system is discussed when a practical system was designed and applied.

  20. GIS Conceptual Data Model

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    In order to set up a conceptual data model that reflects the real world as accurately as possible,this paper firstly reviews and analyzes the disadvantages of previous conceptual data models used by traditional GIS in simulating geographic space,gives a new explanation to geographic space and analyzes its various essential characteristics.Finally,this paper proposes several detailed key points for designing a new type of GIS data model and gives a simple holistic GIS data model.

  1. Modeling Digital Video Database

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    The main purpose of the model is to present how the UnifiedModeling L anguage (UML) can be used for modeling digital video database system (VDBS). It demonstrates the modeling process that can be followed during the analysis phase of complex applications. In order to guarantee the continuity mapping of the mo dels, the authors propose some suggestions to transform the use case diagrams in to an object diagram, which is one of the main diagrams for the next development phases.

  2. Hierarchical Bass model

    Science.gov (United States)

    Tashiro, Tohru

    2014-03-01

    We propose a new model about diffusion of a product which includes a memory of how many adopters or advertisements a non-adopter met, where (non-)adopters mean people (not) possessing the product. This effect is lacking in the Bass model. As an application, we utilize the model to fit the iPod sales data, and so the better agreement is obtained than the Bass model.

  3. Quantal Response: Nonparametric Modeling

    Science.gov (United States)

    2017-01-01

    spline N−spline Fig. 3 Logistic regression 7 Approved for public release; distribution is unlimited. 5. Nonparametric QR Models Nonparametric linear ...stimulus and probability of response. The Generalized Linear Model approach does not make use of the limit distribution but allows arbitrary functional...7. Conclusions and Recommendations 18 8. References 19 Appendix A. The Linear Model 21 Appendix B. The Generalized Linear Model 33 Appendix C. B

  4. Auxiliary Deep Generative Models

    OpenAIRE

    Maaløe, Lars; Sønderby, Casper Kaae; Sønderby, Søren Kaae; Winther, Ole

    2016-01-01

    Deep generative models parameterized by neural networks have recently achieved state-of-the-art performance in unsupervised and semi-supervised learning. We extend deep generative models with auxiliary variables which improves the variational approximation. The auxiliary variables leave the generative model unchanged but make the variational distribution more expressive. Inspired by the structure of the auxiliary variable we also propose a model with two stochastic layers and skip connections...

  5. Avionics Architecture Modelling Language

    Science.gov (United States)

    Alana, Elena; Naranjo, Hector; Valencia, Raul; Medina, Alberto; Honvault, Christophe; Rugina, Ana; Panunzia, Marco; Dellandrea, Brice; Garcia, Gerald

    2014-08-01

    This paper presents the ESA AAML (Avionics Architecture Modelling Language) study, which aimed at advancing the avionics engineering practices towards a model-based approach by (i) identifying and prioritising the avionics-relevant analyses, (ii) specifying the modelling language features necessary to support the identified analyses, and (iii) recommending/prototyping software tooling to demonstrate the automation of the selected analyses based on a modelling language and compliant with the defined specification.

  6. Hierarchical Bass model

    CERN Document Server

    Tashiro, Tohru

    2013-01-01

    We propose a new model about diffusion of a product which includes a memory of how many adopters or advertisements a non-adopter met, where (non-)adopters mean people (not) possessing the product. This effect is lacking in the Bass model. As an application, we utilize the model to fit the iPod sales data, and so the better agreement is obtained than the Bass model.

  7. Artificial neural network modelling

    CERN Document Server

    Samarasinghe, Sandhya

    2016-01-01

    This book covers theoretical aspects as well as recent innovative applications of Artificial Neural networks (ANNs) in natural, environmental, biological, social, industrial and automated systems. It presents recent results of ANNs in modelling small, large and complex systems under three categories, namely, 1) Networks, Structure Optimisation, Robustness and Stochasticity 2) Advances in Modelling Biological and Environmental Systems and 3) Advances in Modelling Social and Economic Systems. The book aims at serving undergraduates, postgraduates and researchers in ANN computational modelling. .

  8. Optimization modeling with spreadsheets

    CERN Document Server

    Baker, Kenneth R

    2015-01-01

    An accessible introduction to optimization analysis using spreadsheets Updated and revised, Optimization Modeling with Spreadsheets, Third Edition emphasizes model building skills in optimization analysis. By emphasizing both spreadsheet modeling and optimization tools in the freely available Microsoft® Office Excel® Solver, the book illustrates how to find solutions to real-world optimization problems without needing additional specialized software. The Third Edition includes many practical applications of optimization models as well as a systematic framework that il

  9. Model Checking Feature Interactions

    DEFF Research Database (Denmark)

    Le Guilly, Thibaut; Olsen, Petur; Pedersen, Thomas;

    2015-01-01

    This paper presents an offline approach to analyzing feature interactions in embedded systems. The approach consists of a systematic process to gather the necessary information about system components and their models. The model is first specified in terms of predicates, before being refined to t...... to timed automata. The consistency of the model is verified at different development stages, and the correct linkage between the predicates and their semantic model is checked. The approach is illustrated on a use case from home automation....

  10. GARCH Modelling of Cryptocurrencies

    Directory of Open Access Journals (Sweden)

    Jeffrey Chu

    2017-10-01

    Full Text Available With the exception of Bitcoin, there appears to be little or no literature on GARCH modelling of cryptocurrencies. This paper provides the first GARCH modelling of the seven most popular cryptocurrencies. Twelve GARCH models are fitted to each cryptocurrency, and their fits are assessed in terms of five criteria. Conclusions are drawn on the best fitting models, forecasts and acceptability of value at risk estimates.

  11. Modelling of Corrosion Cracks

    DEFF Research Database (Denmark)

    Thoft-Christensen, Palle

    Modelling of corrosion cracking of reinforced concrete structures is complicated as a great number of uncertain factors are involved. To get a reliable modelling a physical and mechanical understanding of the process behind corrosion in needed.......Modelling of corrosion cracking of reinforced concrete structures is complicated as a great number of uncertain factors are involved. To get a reliable modelling a physical and mechanical understanding of the process behind corrosion in needed....

  12. Modeling and Remodeling Writing

    Science.gov (United States)

    Hayes, John R.

    2012-01-01

    In Section 1 of this article, the author discusses the succession of models of adult writing that he and his colleagues have proposed from 1980 to the present. He notes the most important changes that differentiate earlier and later models and discusses reasons for the changes. In Section 2, he describes his recent efforts to model young…

  13. Climate models and scenarios

    Energy Technology Data Exchange (ETDEWEB)

    Fortelius, C.; Holopainen, E.; Kaurola, J.; Ruosteenoja, K.; Raeisaenen, J. [Helsinki Univ. (Finland). Dept. of Meteorology

    1996-12-31

    In recent years the modelling of interannual climate variability has been studied, the atmospheric energy and water cycles, and climate simulations with the ECHAM3 model. In addition, the climate simulations of several models have been compared with special emphasis in the area of northern Europe

  14. Crushed Salt Constitutive Model

    Energy Technology Data Exchange (ETDEWEB)

    Callahan, G.D.

    1999-02-01

    The constitutive model used to describe the deformation of crushed salt is presented in this report. Two mechanisms -- dislocation creep and grain boundary diffusional pressure solution -- are combined to form the basis for the constitutive model governing the deformation of crushed salt. The constitutive model is generalized to represent three-dimensional states of stress. Upon complete consolidation, the crushed-salt model reproduces the Multimechanism Deformation (M-D) model typically used for the Waste Isolation Pilot Plant (WIPP) host geological formation salt. New shear consolidation tests are combined with an existing database that includes hydrostatic consolidation and shear consolidation tests conducted on WIPP and southeastern New Mexico salt. Nonlinear least-squares model fitting to the database produced two sets of material parameter values for the model -- one for the shear consolidation tests and one for a combination of the shear and hydrostatic consolidation tests. Using the parameter values determined from the fitted database, the constitutive model is validated against constant strain-rate tests. Shaft seal problems are analyzed to demonstrate model-predicted consolidation of the shaft seal crushed-salt component. Based on the fitting statistics, the ability of the model to predict the test data, and the ability of the model to predict load paths and test data outside of the fitted database, the model appears to capture the creep consolidation behavior of crushed salt reasonably well.

  15. Modeling EERE Deployment Programs

    Energy Technology Data Exchange (ETDEWEB)

    Cort, K. A. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Hostick, D. J. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Belzer, D. B. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Livingston, O. V. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States)

    2007-11-01

    This report compiles information and conclusions gathered as part of the “Modeling EERE Deployment Programs” project. The purpose of the project was to identify and characterize the modeling of deployment programs within the EERE Technology Development (TD) programs, address possible improvements to the modeling process, and note gaps in knowledge in which future research is needed.

  16. Modelling Vocabulary Loss

    Science.gov (United States)

    Meara, Paul

    2004-01-01

    This paper describes some simple simulation models of vocabulary attrition. The attrition process is modelled using a random autonomous Boolean network model, and some parallels with real attrition data are drawn. The paper argues that applying a complex systems approach to attrition can provide some important insights, which suggest that real…

  17. Flexible survival regression modelling

    DEFF Research Database (Denmark)

    Cortese, Giuliana; Scheike, Thomas H; Martinussen, Torben

    2009-01-01

    Regression analysis of survival data, and more generally event history data, is typically based on Cox's regression model. We here review some recent methodology, focusing on the limitations of Cox's regression model. The key limitation is that the model is not well suited to represent time-varyi...

  18. Scalability of human models

    NARCIS (Netherlands)

    Rodarius, C.; Rooij, L. van; Lange, R. de

    2007-01-01

    The objective of this work was to create a scalable human occupant model that allows adaptation of human models with respect to size, weight and several mechanical parameters. Therefore, for the first time two scalable facet human models were developed in MADYMO. First, a scalable human male was

  19. Modeling typical performance measures

    NARCIS (Netherlands)

    Weekers, Anke Martine

    2009-01-01

    In the educational, employment, and clinical context, attitude and personality inventories are used to measure typical performance traits. Statistical models are applied to obtain latent trait estimates. Often the same statistical models as the models used in maximum performance measurement are appl

  20. Model-based geostatistics

    CERN Document Server

    Diggle, Peter J

    2007-01-01

    Model-based geostatistics refers to the application of general statistical principles of modeling and inference to geostatistical problems. This volume provides a treatment of model-based geostatistics and emphasizes on statistical methods and applications. It also features analyses of datasets from a range of scientific contexts.

  1. Zephyr - the prediction models

    DEFF Research Database (Denmark)

    Nielsen, Torben Skov; Madsen, Henrik; Nielsen, Henrik Aalborg

    2001-01-01

    This paper briefly describes new models and methods for predicationg the wind power output from wind farms. The system is being developed in a project which has the research organization Risø and the department of Informatics and Mathematical Modelling (IMM) as the modelling team and all the Dani...

  2. Model Breaking Points Conceptualized

    Science.gov (United States)

    Vig, Rozy; Murray, Eileen; Star, Jon R.

    2014-01-01

    Current curriculum initiatives (e.g., National Governors Association Center for Best Practices and Council of Chief State School Officers 2010) advocate that models be used in the mathematics classroom. However, despite their apparent promise, there comes a point when models break, a point in the mathematical problem space where the model cannot,…

  3. Generalized Poisson sigma models

    CERN Document Server

    Batalin, I; Batalin, Igor; Marnelius, Robert

    2001-01-01

    A general master action in terms of superfields is given which generates generalized Poisson sigma models by means of a natural ghost number prescription. The simplest representation is the sigma model considered by Cattaneo and Felder. For Dirac brackets considerably more general models are generated.

  4. Modern Media Education Models

    Science.gov (United States)

    Fedorov, Alexander

    2011-01-01

    The author supposed that media education models can be divided into the following groups: (1) educational-information models (the study of the theory, history, language of media culture, etc.), based on the cultural, aesthetic, semiotic, socio-cultural theories of media education; (2) educational-ethical models (the study of moral, religions,…

  5. Models for Products

    Science.gov (United States)

    Speiser, Bob; Walter, Chuck

    2011-01-01

    This paper explores how models can support productive thinking. For us a model is a "thing", a tool to help make sense of something. We restrict attention to specific models for whole-number multiplication, hence the wording of the title. They support evolving thinking in large measure through the ways their users redesign them. They assume new…

  6. Genome-Scale Models

    DEFF Research Database (Denmark)

    Bergdahl, Basti; Sonnenschein, Nikolaus; Machado, Daniel

    2016-01-01

    An introduction to genome-scale models, how to build and use them, will be given in this chapter. Genome-scale models have become an important part of systems biology and metabolic engineering, and are increasingly used in research, both in academica and in industry, both for modeling chemical pr...

  7. Rock Properties Model

    Energy Technology Data Exchange (ETDEWEB)

    C. Lum

    2004-09-16

    The purpose of this model report is to document the Rock Properties Model version 3.1 with regard to input data, model methods, assumptions, uncertainties and limitations of model results, and qualification status of the model. The report also documents the differences between the current and previous versions and validation of the model. The rock properties model provides mean matrix and lithophysae porosity, and the cross-correlated mean bulk density as direct input to the ''Saturated Zone Flow and Transport Model Abstraction'', MDL-NBS-HS-000021, REV 02 (BSC 2004 [DIRS 170042]). The constraints, caveats, and limitations associated with this model are discussed in Section 6.6 and 8.2. Model validation accomplished by corroboration with data not cited as direct input is discussed in Section 7. The revision of this model report was performed as part of activities being conducted under the ''Technical Work Plan for: The Integrated Site Model, Revision 05'' (BSC 2004 [DIRS 169635]). The purpose of this revision is to bring the report up to current procedural requirements and address the Regulatory Integration Team evaluation comments. The work plan describes the scope, objectives, tasks, methodology, and procedures for this process.

  8. Deep Stochastic Radar Models

    OpenAIRE

    Wheeler, Tim Allan; Holder, Martin; Winner, Hermann; Kochenderfer, Mykel

    2017-01-01

    Accurate simulation and validation of advanced driver assistance systems requires accurate sensor models. Modeling automotive radar is complicated by effects such as multipath reflections, interference, reflective surfaces, discrete cells, and attenuation. Detailed radar simulations based on physical principles exist but are computationally intractable for realistic automotive scenes. This paper describes a methodology for the construction of stochastic automotive radar models based on deep l...

  9. Bioeconomic and market models

    Science.gov (United States)

    Richard Haynes; Darius Adams; Peter Ince; John Mills; Ralph Alig

    2006-01-01

    The United States has a century of experience with the development of models that describe markets for forest products and trends in resource conditions. In the last four decades, increasing rigor in policy debates has stimulated the development of models to support policy analysis. Increasingly, research has evolved (often relying on computer-based models) to increase...

  10. Model Breaking Points Conceptualized

    Science.gov (United States)

    Vig, Rozy; Murray, Eileen; Star, Jon R.

    2014-01-01

    Current curriculum initiatives (e.g., National Governors Association Center for Best Practices and Council of Chief State School Officers 2010) advocate that models be used in the mathematics classroom. However, despite their apparent promise, there comes a point when models break, a point in the mathematical problem space where the model cannot,…

  11. A Model Performance

    Science.gov (United States)

    Thornton, Bradley D.; Smalley, Robert A.

    2008-01-01

    Building information modeling (BIM) uses three-dimensional modeling concepts, information technology and interoperable software to design, construct and operate a facility. However, BIM can be more than a tool for virtual modeling--it can provide schools with a 3-D walkthrough of a project while it still is on the electronic drawing board. BIM can…

  12. Model Rockets and Microchips.

    Science.gov (United States)

    Fitzsimmons, Charles P.

    1986-01-01

    Points out the instructional applications and program possibilities of a unit on model rocketry. Describes the ways that microcomputers can assist in model rocket design and in problem calculations. Provides a descriptive listing of model rocket software for the Apple II microcomputer. (ML)

  13. Dynamic term structure models

    DEFF Research Database (Denmark)

    Andreasen, Martin Møller; Meldrum, Andrew

    This paper studies whether dynamic term structure models for US nominal bond yields should enforce the zero lower bound by a quadratic policy rate or a shadow rate specification. We address the question by estimating quadratic term structure models (QTSMs) and shadow rate models with at most four...

  14. Modelling: Nature and Use

    DEFF Research Database (Denmark)

    2011-01-01

    Engineering of products and processes is increasingly “model-centric”. Models in their multitudinous forms are ubiquitous, being heavily used for a range of decision making activities across all life cycle phases. This chapter gives an overview of what is a model, the principal activities in the ...

  15. Simplicial chiral models

    CERN Document Server

    Rossi, P; Rossi, Paolo; Tan, Chung I

    1995-01-01

    Principal chiral models on a d-1 dimensional simplex are introduced and studied analytically in the large N limit. The d = 0 , 2, 4 and \\infty models are explicitly solved. Relationship with standard lattice models and with few-matrix systems in the double scaling limit are discussed.

  16. Modeling agriculture in the Community Land Model

    Directory of Open Access Journals (Sweden)

    B. Drewniak

    2013-04-01

    Full Text Available The potential impact of climate change on agriculture is uncertain. In addition, agriculture could influence above- and below-ground carbon storage. Development of models that represent agriculture is necessary to address these impacts. We have developed an approach to integrate agriculture representations for three crop types – maize, soybean, and spring wheat – into the coupled carbon–nitrogen version of the Community Land Model (CLM, to help address these questions. Here we present the new model, CLM-Crop, validated against observations from two AmeriFlux sites in the United States, planted with maize and soybean. Seasonal carbon fluxes compared well with field measurements for soybean, but not as well for maize. CLM-Crop yields were comparable with observations in countries such as the United States, Argentina, and China, although the generality of the crop model and its lack of technology and irrigation made direct comparison difficult. CLM-Crop was compared against the standard CLM3.5, which simulates crops as grass. The comparison showed improvement in gross primary productivity in regions where crops are the dominant vegetation cover. Crop yields and productivity were negatively correlated with temperature and positively correlated with precipitation, in agreement with other modeling studies. In case studies with the new crop model looking at impacts of residue management and planting date on crop yield, we found that increased residue returned to the litter pool increased crop yield, while reduced residue returns resulted in yield decreases. Using climate controls to signal planting date caused different responses in different crops. Maize and soybean had opposite reactions: when low temperature threshold resulted in early planting, maize responded with a loss of yield, but soybean yields increased. Our improvements in CLM demonstrate a new capability in the model – simulating agriculture in a realistic way, complete with

  17. Mechanics of materials model

    Science.gov (United States)

    Meister, Jeffrey P.

    1987-01-01

    The Mechanics of Materials Model (MOMM) is a three-dimensional inelastic structural analysis code for use as an early design stage tool for hot section components. MOMM is a stiffness method finite element code that uses a network of beams to characterize component behavior. The MOMM contains three material models to account for inelastic material behavior. These include the simplified material model, which assumes a bilinear stress-strain response; the state-of-the-art model, which utilizes the classical elastic-plastic-creep strain decomposition; and Walker's viscoplastic model, which accounts for the interaction between creep and plasticity that occurs under cyclic loading conditions.

  18. Integrated ELM modelling

    Energy Technology Data Exchange (ETDEWEB)

    Loennroth, J.S.; Kiviniemi, T. [Association EURATOM-Tekes, Helsinki University of Technology, P. O. Box 4100, 02015 TKK (Finland); Bateman, G.; Kritz, A. [Lehigh University, Bethlehem, PA (United States); Becoulet, M.; Figarella, C.; Garbet, X.; Huysmans, G. [Association Euratom-CEA, CEA Cadarache (France); Beyer, P. [University of Marseille (France); Corrigan, G.; Fundamenski, W. [UKAEA Fusion Association, Culham Science Centre (United Kingdom); Garcia, O.E.; Naulin, V. [Association Euratom-Risoe National Laboratory, Roskilde (Denmark); Janeschitz, G. [Forschungszentrum Karlsruhe (Germany); Johnson, T. [Association Euratom-VR, Royal Institute of Technology, Stockholm (Sweden); Kuhn, S. [Association Euratom-OeAW, University of Innsbruck (Austria); Loarte, A. [EFDA Close Support Unit, Garching (Germany); Nave, F. [Association Euratom-IST, Centro de Fusao Nuclear, Lisbon (Portugal); Onjun, T. [Sirindhorn International Institute of Technology (Thailand); Pacher, G.W. [Hydro Quebec (Canada); Pacher, H.D.; Pankin, A.; Parail, V.; Pitts, R.; Saibene, G.; Snyder, P.; Spence, J.; Tskhakaya, D.; Wilson, H.

    2006-09-15

    This paper presents a short overview of current trends and progress in integrated ELM modelling. First, the concept of integrated ELM modelling is introduced, various interpretations of it are given and the need for it is discussed. Then follows an overview of different techniques and methods used in integrated ELM modelling presented roughly according to physics approached in use and in order of increasing complexity. The paper concludes with a short discussion of open issues and future modelling requirements within the field of integrated ELM modelling. (copyright 2006 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)

  19. CRAC2 model description

    Energy Technology Data Exchange (ETDEWEB)

    Ritchie, L.T.; Alpert, D.J.; Burke, R.P.; Johnson, J.D.; Ostmeyer, R.M.; Aldrich, D.C.; Blond, R.M.

    1984-03-01

    The CRAC2 computer code is a revised version of CRAC (Calculation of Reactor Accident Consequences) which was developed for the Reactor Safety Study. This document provides an overview of the CRAC2 code and a description of each of the models used. Significant improvements incorporated into CRAC2 include an improved weather sequence sampling technique, a new evacuation model, and new output capabilities. In addition, refinements have been made to the atmospheric transport and deposition model. Details of the modeling differences between CRAC2 and CRAC are emphasized in the model descriptions.

  20. Validated dynamic flow model

    DEFF Research Database (Denmark)

    Knudsen, Torben

    2011-01-01

    The purpose with this deliverable 2.5 is to use fresh experimental data for validation and selection of a flow model to be used for control design in WP3-4. Initially the idea was to investigate the models developed in WP2. However, in the project it was agreed to include and focus on a additive...... model turns out not to be useful for prediction of the flow. Moreover, standard Box Jenkins model structures and multiple output auto regressive models proves to be superior as they can give useful predictions of the flow....

  1. UZ Colloid Transport Model

    Energy Technology Data Exchange (ETDEWEB)

    M. McGraw

    2000-04-13

    The UZ Colloid Transport model development plan states that the objective of this Analysis/Model Report (AMR) is to document the development of a model for simulating unsaturated colloid transport. This objective includes the following: (1) use of a process level model to evaluate the potential mechanisms for colloid transport at Yucca Mountain; (2) Provide ranges of parameters for significant colloid transport processes to Performance Assessment (PA) for the unsaturated zone (UZ); (3) Provide a basis for development of an abstracted model for use in PA calculations.

  2. Auxiliary Deep Generative Models

    DEFF Research Database (Denmark)

    Maaløe, Lars; Sønderby, Casper Kaae; Sønderby, Søren Kaae;

    2016-01-01

    Deep generative models parameterized by neural networks have recently achieved state-of-the-art performance in unsupervised and semi-supervised learning. We extend deep generative models with auxiliary variables which improves the variational approximation. The auxiliary variables leave...... the generative model unchanged but make the variational distribution more expressive. Inspired by the structure of the auxiliary variable we also propose a model with two stochastic layers and skip connections. Our findings suggest that more expressive and properly specified deep generative models converge...

  3. Transgenesis for pig models

    Science.gov (United States)

    Yum, Soo-Young; Yoon, Ki-Young; Lee, Choong-Il; Lee, Byeong-Chun

    2016-01-01

    Animal models, particularly pigs, have come to play an important role in translational biomedical research. There have been many pig models with genetically modifications via somatic cell nuclear transfer (SCNT). However, because most transgenic pigs have been produced by random integration to date, the necessity for more exact gene-mutated models using recombinase based conditional gene expression like mice has been raised. Currently, advanced genome-editing technologies enable us to generate specific gene-deleted and -inserted pig models. In the future, the development of pig models with gene editing technologies could be a valuable resource for biomedical research. PMID:27030199

  4. Process modeling style

    CERN Document Server

    Long, John

    2014-01-01

    Process Modeling Style focuses on other aspects of process modeling beyond notation that are very important to practitioners. Many people who model processes focus on the specific notation used to create their drawings. While that is important, there are many other aspects to modeling, such as naming, creating identifiers, descriptions, interfaces, patterns, and creating useful process documentation. Experience author John Long focuses on those non-notational aspects of modeling, which practitioners will find invaluable. Gives solid advice for creating roles, work produ

  5. Modeling Epidemic Network Failures

    DEFF Research Database (Denmark)

    Ruepp, Sarah Renée; Fagertun, Anna Manolova

    2013-01-01

    the SID model’s behavior and impact on the network performance, as well as the severity of the infection spreading. The simulations are carried out in OPNET Modeler. The model provides an important input to epidemic connection recovery mechanisms, and can due to its flexibility and versatility be used......This paper presents the implementation of a failure propagation model for transport networks when multiple failures occur resulting in an epidemic. We model the Susceptible Infected Disabled (SID) epidemic model and validate it by comparing it to analytical solutions. Furthermore, we evaluate...

  6. Modeling Epidemic Network Failures

    DEFF Research Database (Denmark)

    Ruepp, Sarah Renée; Fagertun, Anna Manolova

    2013-01-01

    This paper presents the implementation of a failure propagation model for transport networks when multiple failures occur resulting in an epidemic. We model the Susceptible Infected Disabled (SID) epidemic model and validate it by comparing it to analytical solutions. Furthermore, we evaluate...... the SID model’s behavior and impact on the network performance, as well as the severity of the infection spreading. The simulations are carried out in OPNET Modeler. The model provides an important input to epidemic connection recovery mechanisms, and can due to its flexibility and versatility be used...... to evaluate multiple epidemic scenarios in various network types....

  7. Models of Goldstone gauginos

    Science.gov (United States)

    Alves, Daniele S. M.; Galloway, Jamison; McCullough, Matthew; Weiner, Neal

    2016-04-01

    Models with Dirac gauginos are appealing scenarios for physics beyond the Standard Model. They have smaller radiative corrections to scalar soft masses, a suppression of certain supersymmetry (SUSY) production processes at the LHC, and ameliorated flavor constraints. Unfortunately, they are generically plagued by tachyons charged under the Standard Model, and attempts to eliminate such states typically spoil the positive features. The recently proposed "Goldstone gaugino" mechanism provides a simple realization of Dirac gauginos that is automatically free of dangerous tachyonic states. We provide details on this mechanism and explore models for its origin. In particular, we find SUSY QCD models that realize this idea simply and discuss scenarios for unification.

  8. Complex matrix model duality

    Energy Technology Data Exchange (ETDEWEB)

    Brown, T.W.

    2010-11-15

    The same complex matrix model calculates both tachyon scattering for the c=1 non-critical string at the self-dual radius and certain correlation functions of half-BPS operators in N=4 super- Yang-Mills. It is dual to another complex matrix model where the couplings of the first model are encoded in the Kontsevich-like variables of the second. The duality between the theories is mirrored by the duality of their Feynman diagrams. Analogously to the Hermitian Kontsevich- Penner model, the correlation functions of the second model can be written as sums over discrete points in subspaces of the moduli space of punctured Riemann surfaces. (orig.)

  9. Reconstruction of inflation models

    Energy Technology Data Exchange (ETDEWEB)

    Myrzakulov, Ratbay; Sebastiani, Lorenzo [Eurasian National University, Department of General and Theoretical Physics and Eurasian Center for Theoretical Physics, Astana (Kazakhstan); Zerbini, Sergio [Universita di Trento, Dipartimento di Fisica, Trento (Italy); TIFPA, Istituto Nazionale di Fisica Nucleare, Trento (Italy)

    2015-05-15

    In this paper, we reconstruct viable inflationary models by starting from spectral index and tensor-to-scalar ratio from Planck observations. We analyze three different kinds of models: scalar field theories, fluid cosmology, and f(R)-modified gravity. We recover the well-known R{sup 2} inflation in Jordan-frame and Einstein-frame representation, the massive scalar inflaton models and two models of inhomogeneous fluid. A model of R{sup 2} correction to Einstein's gravity plus a ''cosmological constant'' with an exact solution for early-time acceleration is reconstructed. (orig.)

  10. Mathematical modelling techniques

    CERN Document Server

    Aris, Rutherford

    1995-01-01

    ""Engaging, elegantly written."" - Applied Mathematical ModellingMathematical modelling is a highly useful methodology designed to enable mathematicians, physicists and other scientists to formulate equations from a given nonmathematical situation. In this elegantly written volume, a distinguished theoretical chemist and engineer sets down helpful rules not only for setting up models but also for solving the mathematical problems they pose and for evaluating models.The author begins with a discussion of the term ""model,"" followed by clearly presented examples of the different types of mode

  11. Controlling Modelling Artifacts

    DEFF Research Database (Denmark)

    Smith, Michael James Andrew; Nielson, Flemming; Nielson, Hanne Riis

    2011-01-01

    as the high-level model, so that they can be directly compared. There are two key ideas in our approach — a temporal abstraction, where we only look at the state of the system at certain observable points in time, and a spatial abstraction, where we project onto a smaller state space that summarises...... artifacts that were inadvertently introduced. In this paper, we propose a novel methodology to reason about modelling artifacts, given a detailed model and a highlevel (more abstract) model of the same system. By a series of automated abstraction steps, we lift the detailed model to the same state space...

  12. TEAMS Model Analyzer

    Science.gov (United States)

    Tijidjian, Raffi P.

    2010-01-01

    The TEAMS model analyzer is a supporting tool developed to work with models created with TEAMS (Testability, Engineering, and Maintenance System), which was developed by QSI. In an effort to reduce the time spent in the manual process that each TEAMS modeler must perform in the preparation of reporting for model reviews, a new tool has been developed as an aid to models developed in TEAMS. The software allows for the viewing, reporting, and checking of TEAMS models that are checked into the TEAMS model database. The software allows the user to selectively model in a hierarchical tree outline view that displays the components, failure modes, and ports. The reporting features allow the user to quickly gather statistics about the model, and generate an input/output report pertaining to all of the components. Rules can be automatically validated against the model, with a report generated containing resulting inconsistencies. In addition to reducing manual effort, this software also provides an automated process framework for the Verification and Validation (V&V) effort that will follow development of these models. The aid of such an automated tool would have a significant impact on the V&V process.

  13. Models of the universe

    Science.gov (United States)

    Fischer, Arthur E.

    1996-01-01

    In this paper a theory of models of the universe is proposed. We refer to such models ascosmological models, where a cosmological model is defined as an Einstein-inextendible Einstein spacetime. A cosmological model isabsolute if it is a Lorentz-inextendible Einstein spacetime,predictive if it is globally hyperbolic, andnon-predictive if it is nonglobally-hyperbolic. We discuss several features of these models in the study of cosmology. As an example, any compact Einstein spacetime is always a non-predictive absolute cosmological model, whereas a noncompact complete Einstein spacetime is an absolute cosmological model which may be either predictive or non-predictive. We discuss the important role played by maximal Einstein spacetimes. In particular, we examine the possible proper Lorentz-extensions of such spacetimes, and show that a spatially compact maximal Einstein spacetime is exclusively either a predictive cosmological model or a proper sub-spacetime of a non-predictive cosmological model. Provided that the Strong Cosmic Censorship conjecture is true, a generic spatially compact maximal Einstein spacetime must be a predictive cosmological model. It isconjectured that the Strong Cosmic Censorship conjecture isnot true, and converting a vice to a virtue it is argued that the failure of the Strong Cosmic Censorship conjecture would point to what may be general relativity's greatest prediction of all, namely,that general relativity predicts that general relativity cannot predict the entire history of the universe.

  14. Modelling structured data with Probabilistic Graphical Models

    Science.gov (United States)

    Forbes, F.

    2016-05-01

    Most clustering and classification methods are based on the assumption that the objects to be clustered are independent. However, in more and more modern applications, data are structured in a way that makes this assumption not realistic and potentially misleading. A typical example that can be viewed as a clustering task is image segmentation where the objects are the pixels on a regular grid and depend on neighbouring pixels on this grid. Also, when data are geographically located, it is of interest to cluster data with an underlying dependence structure accounting for some spatial localisation. These spatial interactions can be naturally encoded via a graph not necessarily regular as a grid. Data sets can then be modelled via Markov random fields and mixture models (e.g. the so-called MRF and Hidden MRF). More generally, probabilistic graphical models are tools that can be used to represent and manipulate data in a structured way while modeling uncertainty. This chapter introduces the basic concepts. The two main classes of probabilistic graphical models are considered: Bayesian networks and Markov networks. The key concept of conditional independence and its link to Markov properties is presented. The main problems that can be solved with such tools are described. Some illustrations are given associated with some practical work.

  15. Modeling of ultrasound transducers

    DEFF Research Database (Denmark)

    Bæk, David

    deviation of 5.5 % to 11.0 %. Finite element modeling of piezoceramics in combination with Field II is addressed and reveals the influence of restricting the modeling of transducers to the one-dimensional case. An investigation on modeling capacitive micromachined ultrasonic transducers (CMUT)s with Field......This Ph.D. dissertation addresses ultrasound transducer modeling for medical ultrasound imaging and combines the modeling with the ultrasound simulation program Field II. The project firstly presents two new models for spatial impulse responses (SIR)s to a rectangular elevation focused transducer...... II is addressed. It is shown how a single circular CMUT cell can be well approximated with a simple square transducer encapsulating the cell, and how this influence the modeling of full array elements. An optimal cell discretization with Field II’s mathematical elements is addressed as well...

  16. Making business models

    DEFF Research Database (Denmark)

    Gudiksen, Sune Klok; Poulsen, Søren Bolvig; Buur, Jacob

    2014-01-01

    Well-established companies are currently struggling to secure profits due to the pressure from new players' business models as they take advantage of communication technology and new business-model configurations. Because of this, the business model research field flourishes currently; however......, the modelling approaches proposed still rely on linear, rational conceptions and causal reasoning. Through six business cases we argue that participatory design has a role to play, and indeed, can lead the way into another approach to business modelling, which we call business model making. The paper...... illustrates how the application of participatory business model design toolsets can open up discussions on alternative scenarios through improvisation, mock-up making and design game playing, before qualitative judgment on the most promising scenario is carried out....

  17. Foam process models.

    Energy Technology Data Exchange (ETDEWEB)

    Moffat, Harry K.; Noble, David R.; Baer, Thomas A. (Procter & Gamble Co., West Chester, OH); Adolf, Douglas Brian; Rao, Rekha Ranjana; Mondy, Lisa Ann

    2008-09-01

    In this report, we summarize our work on developing a production level foam processing computational model suitable for predicting the self-expansion of foam in complex geometries. The model is based on a finite element representation of the equations of motion, with the movement of the free surface represented using the level set method, and has been implemented in SIERRA/ARIA. An empirically based time- and temperature-dependent density model is used to encapsulate the complex physics of foam nucleation and growth in a numerically tractable model. The change in density with time is at the heart of the foam self-expansion as it creates the motion of the foam. This continuum-level model uses an homogenized description of foam, which does not include the gas explicitly. Results from the model are compared to temperature-instrumented flow visualization experiments giving the location of the foam front as a function of time for our EFAR model system.

  18. Programming Models in HPC

    Energy Technology Data Exchange (ETDEWEB)

    Shipman, Galen M. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2016-06-13

    These are the slides for a presentation on programming models in HPC, at the Los Alamos National Laboratory's Parallel Computing Summer School. The following topics are covered: Flynn's Taxonomy of computer architectures; single instruction single data; single instruction multiple data; multiple instruction multiple data; address space organization; definition of Trinity (Intel Xeon-Phi is a MIMD architecture); single program multiple data; multiple program multiple data; ExMatEx workflow overview; definition of a programming model, programming languages, runtime systems; programming model and environments; MPI (Message Passing Interface); OpenMP; Kokkos (Performance Portable Thread-Parallel Programming Model); Kokkos abstractions, patterns, policies, and spaces; RAJA, a systematic approach to node-level portability and tuning; overview of the Legion Programming Model; mapping tasks and data to hardware resources; interoperability: supporting task-level models; Legion S3D execution and performance details; workflow, integration of external resources into the programming model.

  19. MODERN MEDIA EDUCATION MODELS

    Directory of Open Access Journals (Sweden)

    Alexander Fedorov

    2011-03-01

    Full Text Available The author supposed that media education models can be divided into the following groups:- educational-information models (the study of the theory, history, language of media culture, etc., based on the cultural, aesthetic, semiotic, socio-cultural theories of media education;- educational-ethical models (the study of moral, religions, philosophical problems relying on the ethic, religious, ideological, ecological, protectionist theories of media education;- pragmatic models (practical media technology training, based on the uses and gratifications and ‘practical’ theories of media education;- aesthetical models (aimed above all at the development of the artistic taste and enriching the skills of analysis of the best media culture examples. Relies on the aesthetical (art and cultural studies theory; - socio-cultural models (socio-cultural development of a creative personality as to the perception, imagination, visual memory, interpretation analysis, autonomic critical thinking, relying on the cultural studies, semiotic, ethic models of media education.

  20. Hydrological land surface modelling

    DEFF Research Database (Denmark)

    Ridler, Marc-Etienne Francois

    Recent advances in integrated hydrological and soil-vegetation-atmosphere transfer (SVAT) modelling have led to improved water resource management practices, greater crop production, and better flood forecasting systems. However, uncertainty is inherent in all numerical models ultimately leading...... and disaster management. The objective of this study is to develop and investigate methods to reduce hydrological model uncertainty by using supplementary data sources. The data is used either for model calibration or for model updating using data assimilation. Satellite estimates of soil moisture and surface...... hydrological and tested by assimilating synthetic hydraulic head observations in a catchment in Denmark. Assimilation led to a substantial reduction of model prediction error, and better model forecasts. Also, a new assimilation scheme is developed to downscale and bias-correct coarse satellite derived soil...

  1. Aware design models

    DEFF Research Database (Denmark)

    Tamke, Martin

    2015-01-01

    Appearing almost alive, a novel set of computational design models can become an active counterpart for architects in the design process. The ability to loop, sense and query and the integration of near real-time simulation provide these models with a depth and agility that allows for instant...... and informed feedback. Introducing the term "Aware models", the paper investigates how computational models become an enabler for a better informed architectural design practice, through the embedding of knowledge about constraints, behaviour and processes of formation and making into generative design models....... The inspection of several computational design projects in architectural research highlights three different types of awareness a model can possess and devises strategies to establish and finally design with aware models. This design practice is collaborative in nature and characterized by a bidirectional flow...

  2. Minimal Markov Models

    CERN Document Server

    Gonzalez-Lopez, Jesus E Garcia Veronica A

    2010-01-01

    In this work we introduce a new and richer class of finite order Markov chain models and address the following model selection problem: find the Markov model with the minimal set of parameters (minimal Markov model) which is necessary to represent a source as a Markov chain of finite order. Let us call $M$ the order of the chain and $A$ the finite alphabet, to determine the minimal Markov model, we define an equivalence relation on the state space $A^{M}$, such that all the sequences of size $M$ with the same transition probabilities are put in the same category. In this way we have one set of $(|A|-1)$ transition probabilities for each category, obtaining a model with a minimal number of parameters. We show that the model can be selected consistently using the Bayesian information criterion.

  3. Multiscale Modeling of Recrystallization

    Energy Technology Data Exchange (ETDEWEB)

    Godfrey, A.W.; Holm, E.A.; Hughes, D.A.; Lesar, R.; Miodownik, M.A.

    1998-12-07

    We propose a multi length scale approach to modeling recrystallization which links a dislocation model, a cell growth model and a macroscopic model. Although this methodology and linking framework will be applied to recrystallization, it is also applicable to other types of phase transformations in bulk and layered materials. Critical processes such as the dislocation structure evolution, nucleation, the evolution of crystal orientations into a preferred texture, and grain size evolution all operate at different length scales. In this paper we focus on incorporating experimental measurements of dislocation substructures, rnisorientation measurements of dislocation boundaries, and dislocation simulations into a mesoscopic model of cell growth. In particular, we show how feeding information from the dislocation model into the cell growth model can create realistic initial microstructure.

  4. CREDIT RISK. DETERMINATION MODELS

    Directory of Open Access Journals (Sweden)

    MIHAELA GRUIESCU

    2012-01-01

    Full Text Available The internationalization of financial flows and banking and the rapid development of markets have changed the financial sector, causing him to respond with force and imagination. Under these conditions, the concerns of financial and banking institutions, rating institutions are increasingly turning to find the best solutions to hedge risks and maximize profits. This paper aims to present a number of advantages, but also limits the Merton model, the first structural model for modeling credit risk. Also, some are extensions of the model, some empirical research and performance known, others such as state-dependent models (SDM, which together with the liquidation process models (LPM, are two recent efforts in the structural models, show different phenomena in real life.

  5. Phyloclimatic modeling: combining phylogenetics and bioclimatic modeling.

    Science.gov (United States)

    Yesson, C; Culham, A

    2006-10-01

    We investigate the impact of past climates on plant diversification by tracking the "footprint" of climate change on a phylogenetic tree. Diversity within the cosmopolitan carnivorous plant genus Drosera (Droseraceae) is focused within Mediterranean climate regions. We explore whether this diversity is temporally linked to Mediterranean-type climatic shifts of the mid-Miocene and whether climate preferences are conservative over phylogenetic timescales. Phyloclimatic modeling combines environmental niche (bioclimatic) modeling with phylogenetics in order to study evolutionary patterns in relation to climate change. We present the largest and most complete such example to date using Drosera. The bioclimatic models of extant species demonstrate clear phylogenetic patterns; this is particularly evident for the tuberous sundews from southwestern Australia (subgenus Ergaleium). We employ a method for establishing confidence intervals of node ages on a phylogeny using replicates from a Bayesian phylogenetic analysis. This chronogram shows that many clades, including subgenus Ergaleium and section Bryastrum, diversified during the establishment of the Mediterranean-type climate. Ancestral reconstructions of bioclimatic models demonstrate a pattern of preference for this climate type within these groups. Ancestral bioclimatic models are projected into palaeo-climate reconstructions for the time periods indicated by the chronogram. We present two such examples that each generate plausible estimates of ancestral lineage distribution, which are similar to their current distributions. This is the first study to attempt bioclimatic projections on evolutionary time scales. The sundews appear to have diversified in response to local climate development. Some groups are specialized for Mediterranean climates, others show wide-ranging generalism. This demonstrates that Phyloclimatic modeling could be repeated for other plant groups and is fundamental to the understanding of

  6. Modeling agriculture in the Community Land Model

    Directory of Open Access Journals (Sweden)

    B. Drewniak

    2012-12-01

    Full Text Available The potential impact of climate change on agriculture is uncertain. In addition, agriculture could influence above- and below-ground carbon storage. Development of models that represent agriculture is necessary to address these impacts. We have developed an approach to integrate agriculture representations for three crop types – maize, soybean, and spring wheat – into the coupled carbon-nitrogen version of the Community Land Model (CLM, to help address these questions. Here we present the new model, CLM-Crop, validated against observations from two AmeriFlux sites in the United States, planted with maize and soybean. Seasonal carbon fluxes compared well with field measurements. CLM-Crop yields were comparable with observations in some regions, although the generality of the crop model and its lack of technology and irrigation made direct comparison difficult. CLM-Crop was compared against the standard CLM3.5, which simulates crops as grass. The comparison showed improvement in gross primary productivity in regions where crops are the dominant vegetation cover. Crop yields and productivity were negatively correlated with temperature and positively correlated with precipitation. In case studies with the new crop model looking at impacts of residue management and planting date on crop yield, we found that increased residue returned to the litter pool increased crop yield, while reduced residue returns resulted in yield decreases. Using climate controls to signal planting date caused different responses in different crops. Maize and soybean had opposite reactions: when low temperature threshold resulted in early planting, maize responded with a loss of yield, but soybean yields increased. Our improvements in CLM demonstrate a new capability in the model – simulating agriculture in a realistic way, complete with fertilizer and residue management practices. Results are encouraging, with improved representation of human influences on the land

  7. Modeling local dependence in longitudinal IRT models

    DEFF Research Database (Denmark)

    Larsen, Maja Olsbjerg; Christensen, Karl Bang

    2015-01-01

    Measuring change in a latent variable over time is often done using the same instrument at several time points. This can lead to dependence between responses across time points for the same person yielding within person correlations that are stronger than what can be attributed to the latent...... variable. Ignoring this can lead to biased estimates of changes in the latent variable. In this paper we propose a method for modeling local dependence in the longitudinal 2PL model. It is based on the concept of item splitting, and makes it possible to correctly estimate change in the latent variable....

  8. Constitutive models in LAME.

    Energy Technology Data Exchange (ETDEWEB)

    Hammerand, Daniel Carl; Scherzinger, William Mark

    2007-09-01

    The Library of Advanced Materials for Engineering (LAME) provides a common repository for constitutive models that can be used in computational solid mechanics codes. A number of models including both hypoelastic (rate) and hyperelastic (total strain) constitutive forms have been implemented in LAME. The structure and testing of LAME is described in Scherzinger and Hammerand ([3] and [4]). The purpose of the present report is to describe the material models which have already been implemented into LAME. The descriptions are designed to give useful information to both analysts and code developers. Thus far, 33 non-ITAR/non-CRADA protected material models have been incorporated. These include everything from the simple isotropic linear elastic models to a number of elastic-plastic models for metals to models for honeycomb, foams, potting epoxies and rubber. A complete description of each model is outside the scope of the current report. Rather, the aim here is to delineate the properties, state variables, functions, and methods for each model. However, a brief description of some of the constitutive details is provided for a number of the material models. Where appropriate, the SAND reports available for each model have been cited. Many models have state variable aliases for some or all of their state variables. These alias names can be used for outputting desired quantities. The state variable aliases available for results output have been listed in this report. However, not all models use these aliases. For those models, no state variable names are listed. Nevertheless, the number of state variables employed by each model is always given. Currently, there are four possible functions for a material model. This report lists which of these four methods are employed in each material model. As far as analysts are concerned, this information is included only for the awareness purposes. The analyst can take confidence in the fact that model has been properly implemented

  9. Application of retrospective time integration scheme to the prediction of torrential rain

    Institute of Scientific and Technical Information of China (English)

    Feng Guo-Lin; Dong Wen-Jie; Jia Xiao-Jing

    2004-01-01

    The retrospective time integration scheme presented on the principle of the self-memory of the atmosphere is applied to the mesoscale grid model MM5, constructing a mesoscale self-memorial model SMM5, and then the shortrange prediction experiments of torrential rain are performed in this paper. Results show that in comparison with MM5 the prediction accuracy of SMM5 is obviously improved due to its utilization of multiple time level past observations,and the precipitation area and intensity predicted by SMM5 are closer to observational fields than those by MM5.

  10. Modeling Quantum Well Lasers

    Directory of Open Access Journals (Sweden)

    Dan Alexandru Anghel

    2012-01-01

    Full Text Available In semiconductor laser modeling, a good mathematical model gives near-reality results. Three methods of modeling solutions from the rate equations are presented and analyzed. A method based on the rate equations modeled in Simulink to describe quantum well lasers was presented. For different signal types like step function, saw tooth and sinus used as input, a good response of the used equations is obtained. Circuit model resulting from one of the rate equations models is presented and simulated in SPICE. Results show a good modeling behavior. Numerical simulation in MathCad gives satisfactory results for the study of the transitory and dynamic operation at small level of the injection current. The obtained numerical results show the specific limits of each model, according to theoretical analysis. Based on these results, software can be built that integrates circuit simulation and other modeling methods for quantum well lasers to have a tool that model and analysis these devices from all points of view.

  11. Geochemical modeling: a review

    Energy Technology Data Exchange (ETDEWEB)

    Jenne, E.A.

    1981-06-01

    Two general families of geochemical models presently exist. The ion speciation-solubility group of geochemical models contain submodels to first calculate a distribution of aqueous species and to secondly test the hypothesis that the water is near equilibrium with particular solid phases. These models may or may not calculate the adsorption of dissolved constituents and simulate the dissolution and precipitation (mass transfer) of solid phases. Another family of geochemical models, the reaction path models, simulates the stepwise precipitation of solid phases as a result of reacting specified amounts of water and rock. Reaction path models first perform an aqueous speciation of the dissolved constituents of the water, test solubility hypotheses, then perform the reaction path modeling. Certain improvements in the present versions of these models would enhance their value and usefulness to applications in nuclear-waste isolation, etc. Mass-transfer calculations of limited extent are certainly within the capabilities of state-of-the-art models. However, the reaction path models require an expansion of their thermodynamic data bases and systematic validation before they are generally accepted.

  12. Modelling Farm Animal Welfare.

    Science.gov (United States)

    Collins, Lisa M; Part, Chérie E

    2013-05-16

    The use of models in the life sciences has greatly expanded in scope and advanced in technique in recent decades. However, the range, type and complexity of models used in farm animal welfare is comparatively poor, despite the great scope for use of modeling in this field of research. In this paper, we review the different modeling approaches used in farm animal welfare science to date, discussing the types of questions they have been used to answer, the merits and problems associated with the method, and possible future applications of each technique. We find that the most frequently published types of model used in farm animal welfare are conceptual and assessment models; two types of model that are frequently (though not exclusively) based on expert opinion. Simulation, optimization, scenario, and systems modeling approaches are rarer in animal welfare, despite being commonly used in other related fields. Finally, common issues such as a lack of quantitative data to parameterize models, and model selection and validation are discussed throughout the review, with possible solutions and alternative approaches suggested.

  13. Modelling Farm Animal Welfare

    Directory of Open Access Journals (Sweden)

    Chérie E. Part

    2013-05-01

    Full Text Available The use of models in the life sciences has greatly expanded in scope and advanced in technique in recent decades. However, the range, type and complexity of models used in farm animal welfare is comparatively poor, despite the great scope for use of modeling in this field of research. In this paper, we review the different modeling approaches used in farm animal welfare science to date, discussing the types of questions they have been used to answer, the merits and problems associated with the method, and possible future applications of each technique. We find that the most frequently published types of model used in farm animal welfare are conceptual and assessment models; two types of model that are frequently (though not exclusively based on expert opinion. Simulation, optimization, scenario, and systems modeling approaches are rarer in animal welfare, despite being commonly used in other related fields. Finally, common issues such as a lack of quantitative data to parameterize models, and model selection and validation are discussed throughout the review, with possible solutions and alternative approaches suggested.

  14. Product Modelling for Model-Based Maintenance

    NARCIS (Netherlands)

    Houten, van F.J.A.M.; Tomiyama, T.; Salomons, O.W.

    1998-01-01

    The paper describes the fundamental concepts of maintenance and the role that information technology can play in the support of maintenance activities. Function-Behaviour-State modelling is used to describe faults and deterioration of mechanisms in terms of user perception and measurable quantities.

  15. Hydrological land surface modelling

    DEFF Research Database (Denmark)

    Ridler, Marc-Etienne Francois

    to imperfect model forecasts. It remains a crucial challenge to account for system uncertainty, so as to provide model outputs accompanied by a quantified confidence interval. Properly characterizing and reducing uncertainty opens-up the opportunity for risk-based decision-making and more effective emergency...... and disaster management. The objective of this study is to develop and investigate methods to reduce hydrological model uncertainty by using supplementary data sources. The data is used either for model calibration or for model updating using data assimilation. Satellite estimates of soil moisture and surface...... temperature are explored in a multi-objective calibration experiment to optimize the parameters in a SVAT model in the Sahel. The two satellite derived variables were effective at constraining most land-surface and soil parameters. A data assimilation framework is developed and implemented with an integrated...

  16. Aeroservoelasticity modeling and control

    CERN Document Server

    Tewari, Ashish

    2015-01-01

    This monograph presents the state of the art in aeroservoelastic (ASE) modeling and analysis and develops a systematic theoretical and computational framework for use by researchers and practicing engineers. It is the first book to focus on the mathematical modeling of structural dynamics, unsteady aerodynamics, and control systems to evolve a generic procedure to be applied for ASE synthesis. Existing robust, nonlinear, and adaptive control methodology is applied and extended to some interesting ASE problems, such as transonic flutter and buffet, post-stall buffet and maneuvers, and flapping flexible wing. The author derives a general aeroservoelastic plant via the finite-element structural dynamic model, unsteady aerodynamic models for various regimes in the frequency domain, and the associated state-space model by rational function approximations. For more advanced models, the full-potential, Euler, and Navier-Stokes methods for treating transonic and separated flows are also briefly addressed. Essential A...

  17. The IIR evaluation model

    DEFF Research Database (Denmark)

    Borlund, Pia

    2003-01-01

    An alternative approach to evaluation of interactive information retrieval (IIR) systems, referred to as the IIR evaluation model, is proposed. The model provides a framework for the collection and analysis of IR interaction data. The aim of the model is two-fold: 1) to facilitate the evaluation...... assessments. The IIR evaluation model is presented as an alternative to the system-driven Cranfield model (Cleverdon, Mills & Keen, 1966; Cleverdon & Keen, 1966) which still is the dominant approach to the evaluation of IR and IIR systems. Key elements of the IIR evaluation model are the use of realistic...... of IIR systems as realistically as possible with reference to actual information searching and retrieval processes, though still in a relatively controlled evaluation environment; and 2) to calculate the IIR system performance taking into account the non-binary nature of the assigned relevance...

  18. Multiscale cancer modeling.

    Science.gov (United States)

    Deisboeck, Thomas S; Wang, Zhihui; Macklin, Paul; Cristini, Vittorio

    2011-08-15

    Simulating cancer behavior across multiple biological scales in space and time, i.e., multiscale cancer modeling, is increasingly being recognized as a powerful tool to refine hypotheses, focus experiments, and enable more accurate predictions. A growing number of examples illustrate the value of this approach in providing quantitative insights in the initiation, progression, and treatment of cancer. In this review, we introduce the most recent and important multiscale cancer modeling works that have successfully established a mechanistic link between different biological scales. Biophysical, biochemical, and biomechanical factors are considered in these models. We also discuss innovative, cutting-edge modeling methods that are moving predictive multiscale cancer modeling toward clinical application. Furthermore, because the development of multiscale cancer models requires a new level of collaboration among scientists from a variety of fields such as biology, medicine, physics, mathematics, engineering, and computer science, an innovative Web-based infrastructure is needed to support this growing community.

  19. Validation of simulation models

    DEFF Research Database (Denmark)

    Rehman, Muniza; Pedersen, Stig Andur

    2012-01-01

    In philosophy of science, the interest for computational models and simulations has increased heavily during the past decades. Different positions regarding the validity of models have emerged but the views have not succeeded in capturing the diversity of validation methods. The wide variety...... of models has been somewhat narrow-minded reducing the notion of validation to establishment of truth. This article puts forward the diversity in applications of simulation models that demands a corresponding diversity in the notion of validation....... of models with regards to their purpose, character, field of application and time dimension inherently calls for a similar diversity in validation approaches. A classification of models in terms of the mentioned elements is presented and used to shed light on possible types of validation leading...

  20. Spatial cluster modelling

    CERN Document Server

    Lawson, Andrew B

    2002-01-01

    Research has generated a number of advances in methods for spatial cluster modelling in recent years, particularly in the area of Bayesian cluster modelling. Along with these advances has come an explosion of interest in the potential applications of this work, especially in epidemiology and genome research. In one integrated volume, this book reviews the state-of-the-art in spatial clustering and spatial cluster modelling, bringing together research and applications previously scattered throughout the literature. It begins with an overview of the field, then presents a series of chapters that illuminate the nature and purpose of cluster modelling within different application areas, including astrophysics, epidemiology, ecology, and imaging. The focus then shifts to methods, with discussions on point and object process modelling, perfect sampling of cluster processes, partitioning in space and space-time, spatial and spatio-temporal process modelling, nonparametric methods for clustering, and spatio-temporal ...