Temperature inversions in the boundary layer over Prague

Temperature inversions in the boundary layer over Prague Abstract The main objective of this study is to analyze temperature inversions in the atmospheric boundary layer (ABL) over Prague. In the first part, the concept of the ABL is defined and main theoretical aspects of air stratification are explored. The main part of the background research summarizes current knowledge of temperature inversions, especially how the landscape pattern influences their development and parameters under different synoptic situations, and methods used for their detection, measurement and evaluation. Considering the theme of the thesis, main geographic factors influencing temperature inversions in the area of Prague are also defined. The focus of actions is placed on inversions analysis based upon time series of Praha-Libuš rawinsonde station. Homogeneity of used data is tested and all inversions within the 2000- meters-thick-layer close to the ground are derived. Diurnal, annual and interannual frequency variations are described. Significance of long-term trends is tested and trends are compared to data from Prostějov and Kümmersbruck stations. Keywords: temperature inversions, boundary layer, climate, Pragu

Long-term trends of wind velocity in Bohemia

Department of Physical Geography and GeoecologyKatedra fyzické geografie a geoekologieFaculty of SciencePřírodovědecká fakult

The application of atmospheric circulation classifications in the interpretation of climate model outputs

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..

Využití klasifikací atmosférické cirkulace v interpretaci výstupů z klimatických modelů

Využití klasifikací atmosférické cirkulace v interpretaci výstupů z klimatických modelů Mgr. Jan Stryhal Automatizované klasifikace polí atmosférické cirkulace (zkráceně cirkulační klasifikace) jsou nástrojem hojně užívaným v synoptické a dynamické klimatologii ke studiu atmosférické cirkulace a vazeb mezi atmosférickou cirkulací a nejrůznějšími atmosférickými, environmentálními a společenskými jevy. Aplikace cirkulačních klasifikací na výstupy dynamických modelů atmosféry prodělaly od prvních studií před zhruba 30 lety značný rozvoj, odrážející rychlý rozvoj statistiky, výpočetní techniky a přirozeně také klimatologického výzkumu, který se tváří v tvář paradigmatu antropogenních klimatických změn stává více a více závislým na simulacích atmosféry. Nekoordinované využívání nejrůznějších statistických přístupů v analýze výstupů globálních modelů klimatu a jejich ensemblů a nahodilý výběr cirkulačních proměnných, prostorových a časových domén a referenčních datových souborů vyústily v potřebu srovnávacích studií, které by objasnily, nakolik je srovnání klasifikací ve dvou datových souborech citlivé k subjektivním volbám. Tato práce reaguje na tuto potřebu zaměřením na roli, jakou hrají v podobných výzkumech volba klasifikační metody a v případě validace modelů volba referenční reanalýzy atmosféry. Za...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...Katedra fyzické geografie a geoekologieDepartment of Physical Geography and GeoecologyPřírodovědecká fakultaFaculty of Scienc

Klasifikace atmosférické cirkulace

The goal of the present article is to provide a brief overview of the development and usage of classifications of atmospheric circulation, particularly classifications of circulation patterns. In the first section, the motivation to conduct research into atmospheric circulation and the role of classifications in this research are discussed. In addition, basic approaches to classification are described. In the second section, manual classification methods are introduced; the focus is on those methods that have been widely used in the Czech literature - the synoptic catalogues of Brádka and Hess-Brezowsky. To our knowledge, such an overview has not been published yet. In the third section, the development of automated methods is described and the most commonly used methods are briefly introduced. We conclude with an overview of one of the fastest developing fields in synoptic climatology - the application of circulation classifications to climate modelling.30032