National Repository of Grey Literature 4 records found  Search took 0.01 seconds. 
Numerical weather prediction with WRF model
Kotků, Jirka ; Belda, Michal (advisor) ; Huszár, Peter (referee)
This bachelor's thesis deals with the comparison of the simulation results using different vertical coordinate systems, namely the terrain following system and the hybrid vertical coordinate system. We begin with the brief introduction of numerical prediction models in general and then the introduction of the WRF model used in this thesis. The attention is paid to the description of vertical coordinate systems as well as to the presentation of its components and the process of starting a simulation. The next section describes the setting of the WRF model used in this thesis. It is followed by the graphical output of the simulations with the comparison of the results. Comparison of the vertical temperature and wind speed profile was made with real data from the soundings performed in Prague-Libuš by the Czech Hydrometeorological Institute.
On the assessment of urbanization application in weather forecasting model
Nováková, Tereza ; Halenka, Tomáš (advisor) ; Žák, Michal (referee)
Built-up areas represent an artifiial impait to natural environment with large spatial variability and speiifi meihaniit radiationt thermal and ihemiial properties. Despite of inireasing horizontal resolution of numeriial weather prediition modelst the impait of loial built-up area on mesosynoptiv weather phenomena is still not well resolved. Therefore it is neiessary to use some of urban environment modelst whiih were designed to parameterize speiifi urban prosiessest not expliiitly resolved inside the grid box. In the thesis main urban iharaiteristiis are explained (impait on the struiture of boundary layert radiation and heat balanie of urban environment or urban heat island)t basii priniiples of urbanization appliiation in the numeriial weather model are desiribedt as well as different urban parameterizations available in numeriial model WRFe (Weather Reseaih and Feoreiasting). Number of validation experiments were performed for summer and winter episode in non-hydrostatii mode at 3t3 km resolutiont where different urban parametrizationst antropogenii heat adjustment and impait of mosaii land-use were tested. April 2018 Prague weather foreiast was verifiated in ionsideration of urban heat island.
Tests and validation of WRF model for weather forecasting
Nováková, Tereza ; Halenka, Tomáš (advisor) ; Žák, Michal (referee)
Testing and validation of the numerical prediction model is an important part of its usage for weather prediction. The simulations have been performed with model WRF (Weather Research and Forecasting), of which basic principles are described. The simulation was set up in reanalysis mode, i.e. with perfect boundary conditions, for one month, July of 2000. The simulation in hydrostatic approximation with 10 km resolution is compared to the simulation with one nested domain in non-hydrostatic mode with 2 km resolution. The study is aimed at the convective and stratiform precipitation in daily total amount of precipitation and compared to the total amount from observed data. In addition, a two-day weather forecast was validated. The forecast has been run daily since January 2016 at the Department of Atmospheric Physics. Standard deviation of 24 and 48 hour forecast is compared with GFS global model analysis. Powered by TCPDF (www.tcpdf.org)
Utilization of analysis of the spatial relationships between meteorological variables in data assimilation into a numerical weather prediction model
Sedláková, Klára ; Sokol, Zbyněk (advisor) ; Řezáčová, Daniela (referee)
UTILIZATION OF ANALYSIS OF THE SPATIAL RELATIONSHIPS BETWEEN METEOROLO- GICAL VARIABLES IN DATA ASSIMILATION INTO A NUMERICAL WEATHER PREDICTION MODEL Quality of initial conditions has a big impact on the accuracy of numerical forecast. The aim of the preparation of the initial conditions is to modify the first guess of the atmospheric state based on the observed data of the meteorological variables so it fit the actual atmospheric state. At present these conditions are usually prepared by objective analysis or by assimilating measured data into model fields. One of the method of the data assimilation is a 3D variational method (3D VAR). It prepares the initial model conditions so that the model fields correspond to actual measured values, while maintaining the spatial relationships between the values of model variables. By utulising the spatial relationships we can improve the initial conditions and so the forecast. In this work we concentrate on study of the spatial relationship in the convective storms based on correlation analysis of the model variables. We used the model data from COSMO model with horizontal resolution 2.8 km, which were describing 152 convective storms in all the vertical levels. The analysis proved storng relationship between vertical speed, vertical speed and air...

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