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Trendy slunečního svitu na meteorologických stanicích s dlouhou dobou měření
Opatrná, Petra ; Sládek, Ivan (vedoucí práce) ; Hostýnek, Jiří (oponent)
One of the main objectives of this thesis is to identify the trends of sunshine which was measured on the meteorological stations and to explain it by the help of synoptical situations. Further, I would like to define the period, in which the days without sunshine dominate and the period, when the total of sunshine is higher, and to determine their influence on human's organism by means of the T and H index. I used data from eight meteorological stations, which are equable dislocated all around Czech Republic and are situated in the different elevations above sea level. Two of these meteorological stations (Praha - Karlov and Milešovka) have series of measurements which are in time longer than eighty years. In the first part of this thesis, I describe the measurement of sunshine and the factors, which affect it. Then I focus on the year totals of sunshine and I uncover their trends. The final chapters deal with the periods without sunshine which are called the dark periods and with the periods with higher total of sunshine which are called the periods of sunshine plentitude and their peripheries. The amount of sunshine had been going up until the fifties of the last century, after that came a distinct fall to the eighties when the trend was changing again and was raising up slowly. This fact harmonizes with...
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Regime of Thunderstorm occurence in Slovakia
Kontrošová, Jana ; Hošek, Jiří (oponent) ; Sládek, Ivan (vedoucí práce)
4 Abstract The subject matter of my thesis is the regime of thunderstorm occurrence in Slovakia. In the theoretic part of my work, I deal with thunderstorm categorization, condition of its creation and development and with side-effect phenomena. I also mention continentality of climate, which is linked with disintegration and occurrence of days of thunderstorms and thunderstorms. In the practical part, I focus on statistic analysis of number of days of thunderstorms and thunderstorms at the Irish meteorological station Valentia, which represents ocean climate and at 5 Slovak meteorological stations with continental climate in the period of 1961 - 2006 or 2007. I study the trend during years, months, seasons and number of thunderstorm phenomena at the stations, while comparing principles of oceanic and continental climate in the context of thunderstorms and days of thunderstorms occurrence. The main object of my thesis it to define thunderstorm season at each station by method of cumulative series designed by I. Sládek. Conventionally specified seasons do not always match reality. By this method, it is able to determine the natural beginning, end and duration of seasons according to selected climatological parameter. The thunderstorm season at Slovak meteorological stations usually begins at 3rd of May, ends...
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Zvláštnosti pražského klimatu a jeho vztah ke znečištění ovzduší
Hošek, Jiří ; Sládek, Ivan (vedoucí práce) ; Žák, Michal (oponent) ; Prošek, Pavel (oponent)
1. Uvod Klima velkých měst je ýznamnou složkou života stále rostouci ěásti obyvatelstva, a proto je sfudováno se zvyšujicí se intenzitou. Velkoměsta maji své specifické mezoklima, krere se projevuje zejmáta vyššíteplotou a nižšívlhkostí vzduchu. Důvodem těchto klimaticlcých zvláštnostíje převládající nepropustný povrch, diky kterému dochází k urychlenému odtoku sráŽek, a umělým materiálům, diky nimž město funguje ve dne jako absorbér a v noci jako genenítor tepla. Dalšívlastnosti klimatu velkoměsta jsou ovlivněny především snižením albeda aktivního powchu, emisemi tepla, zýšenímdrsnosti povrchu a znečištěnímovzduší.Společně mají t5rto faktory vliv na teplotu a pole větru nad městskou oblastí' Cílem této pnáce bylo určit statistické charakteristiky pole větru a přízemníteploý : zástavbě na územl Prahy a jejich vaah kzatížen|lokalit znečištěnímovzduší.Prvním trokem bylo namodelovat a na základě dostupných dat verifikovat pole přízemního proudění -sd územímPrahy s použitim numerického modelu. Byly také počíttímydalšíproměnné jako ..rsř. směšovacívýška' ktení je důležiýmfaktorem pro rozpýl škodlivin. Na ýpoěet -ludění nad městem navápa|o vyhodnocení tepelné bilance zastavěného aktivního powchu. ..:.rmu bylo pouŽito velmi rozšířenéhoschématu, které řešítento problém i pro velmi <:nplikovaný powch města....
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On the thermally stratified atmospheric flow modeling
Sládek, Ivo ; Kozel, K. ; Jaňour, Zbyněk
The paper deals with a numerical study devoted to thermally /indifferently stratified atmospheric boundary layer flow. The main objective is related to definition of the model and flow conditions as well as to presentation of some first numerical results concerning the flow over selected hill configuration under the indifferent thermal conditions. The mathematical model is based on the system of Reynolds-averaged Navier Stokes (RANS)equations closed by two-equation k-e turbulence model together with wall functions.The thermal stratification is modeled using transport equation for the potential temperature. The finite volume method and the explicit Runge-Kutta time integration method are utilized for the numerics. A 2D-hill test case with a rough wall has been chosen to perform numerical test.
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On the validation study devoted to stratified atmospheric flow over an isolated hill
Sládek, Ivo ; Kozel, Karel ; Jaňour, Zbyněk
The paper deals with description of the validation model, °ow conditions and mainly it presents some numerical results. Reference and input data for the validation study are based on work of Eidsvik [3]. The mathematical model is based on the system of RANS-equations closed by two-equation k ¡ " turbulence model together with wall functions. The thermal strati¯cation is modeled using transport equation for the potential temperature. The ¯nite volume method and the explicit Runge{Kutta time integration method are utilized for the numerics.
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