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The application of atmospheric circulation classifications in the interpretation of climate model outputs
Stryhal, Jan ; Huth, Radan (advisor) ; Halenka, Tomáš (referee) ; Beranová, Romana (referee)
The application of atmospheric circulation classifications in the interpretation of climate model outputs Mgr. Jan Stryhal Automated (computer-assisted) classifications of atmospheric circulation patterns (circulation classifications, for short) constitute a tool widely used in synoptic and dynamic climatology to study atmospheric circulation and its link to various atmospheric, environmental, and societal phenomena. The application of circulation classifications to output of dynamical models of the atmosphere has developed considerably since the pioneering studies about three decades ago, reflecting rapid development in statistics, computing technology, and-naturally-climatological research, increasingly more and more dependent on simulations of the atmosphere, facing the paradigm of anthropogenic climate change. An uncoordinated use of various statistical approaches to analyzing output of global climate models (GCM) or their various ensembles, and an arbitrary selection of circulation variables, spatial and temporal domains, and reference datasets, have contributed to a need for a comparative study, which would shed some light on the sensitivity of studies dealing with an intercomparison of circulation classifications in two datasets to subjective choices. The present thesis responds to this need...
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Long-term precipitation changes in Europe in different data sources
Vít, Václav ; Huth, Radan (advisor) ; Crhová, Lenka (referee)
The subject of this diploma thesis is the analysis of long-term changes in precipitation in Europe over the period 1961 - 2011. Emphasis is placed on determining differences in values of trends in precipitation among selected data sources and on analyzing the spatial distribution of annual and seasonal changes in precipitation in Europe, including a discussion of possible causes of differences in these changes in individual areas. Another aim is to illustrate, describe and account for the differences in trend values among different data sources: the ECA&D station database, the interpolation network data sets E-OBS and CRU TS and two reanalyses JRA-55 and NCEP/NCAR. Depending on the amount and quality of data available for the comparison of data sets, changes in precipitation totals were described over a long-term scale in absolute and also, to a lesser degree, in relative values. The first part summarizes the scientific literature dealing with the changes in precipitation characteristics throughout the world and in Europe. There follows a description of the suitability of individual types of data sources for estimating trends in precipitation totals. Scientific articles usually describe long-term changes based on a single data source rather than using a variety of individual types of data sources....
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The application of atmospheric circulation classifications in the interpretation of climate model outputs
Stryhal, Jan ; Huth, Radan (advisor) ; Halenka, Tomáš (referee) ; Beranová, Romana (referee)
The application of atmospheric circulation classifications in the interpretation of climate model outputs Mgr. Jan Stryhal Automated (computer-assisted) classifications of atmospheric circulation patterns (circulation classifications, for short) constitute a tool widely used in synoptic and dynamic climatology to study atmospheric circulation and its link to various atmospheric, environmental, and societal phenomena. The application of circulation classifications to output of dynamical models of the atmosphere has developed considerably since the pioneering studies about three decades ago, reflecting rapid development in statistics, computing technology, and-naturally-climatological research, increasingly more and more dependent on simulations of the atmosphere, facing the paradigm of anthropogenic climate change. An uncoordinated use of various statistical approaches to analyzing output of global climate models (GCM) or their various ensembles, and an arbitrary selection of circulation variables, spatial and temporal domains, and reference datasets, have contributed to a need for a comparative study, which would shed some light on the sensitivity of studies dealing with an intercomparison of circulation classifications in two datasets to subjective choices. The present thesis responds to this need...
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Manifestation of chaotic behavior in observed and simulated series of climatic variables
Skořepa, Jan ; Mikšovský, Jiří (advisor) ; Raidl, Aleš (referee)
Diplomová práce se věnuje analýze chaotického chování v řadách (pseudo)pozorovaných a simulovaných klimatických veličin. Nejprve objasňuji ně- které základní teoretické pojmy související s dynamickými systémy. Potom se zabývám zp·soby rekonstrukce fázového prostoru a uvedu metody odhadu kore- lační dimenze a největšího Ljapunovova exponentu. V praktické části se zabývám pr·měrnou denní teplotou z reanalýz ERA-40 a reanalýzami NCEP/NCAR v tlakových hladinách 850 a 500 hPa z let 1960-2000. Nejprve zkoumám podrobně jednu vybranou řadu. Používám např. metodu falešných soused· a určuji míru vzájemné informace. Zjiš'uji, že korelační dimenze nenabývá konkrétní hodnotu. Pro analýzu celých tlakových hladin vyvíjím program, který počítá divergenci blízkých trajektorií, což je postup používaný při výpočtu největšího Ljapunovo- va exponentu. Tento program postupně aplikuji na oblasti velikosti 20◦ × 30◦ kterými je pokryta celá zeměkoule. Postupně ukazuji a srovnávám výsledky pro reanalýzy v obou tlakových hladinách s ročním chodem a odečteným ročním cho- dem. Tuto metodu aplikuji na výstupy globálních klimatických model· HadCM3 a MPI-ESM-MR v hladině 500 hPa. Podobnou analýzu ještě uskutečňuji u jed- nodimenzionálních řad teploty u reanalýz a u model·. Výsledky opět vizuálně srovnávám. 1
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