|
|
Continentality of climate over Europe
Hudek, Jakub ; Holtanová, Eva (advisor) ; Kliegrová, Stanislava (referee)
In present work the continentality of climate over Europe is studied. Attention is given to its basic characteristics, geographic distribution and its dependences on latitude and longitude. Firstly basic terms such as annual air temperature amplitude, thermal continentality and corresponding indices that characterize it are described. Attention is paid to the geographic distribution of continental indices for two reference periods (1951 - 1980 and 1981 - 2010) and the differences between them. The dependences of individual indices on latitude and longitude in order to capture in greater detail their properties are also studied. The results have shown that there has been considerable change of continentality between these periods in most of Europe's territory, which is described in detail in this work.
|
|
|
Long-Term Changes in Cloudiness and Sunshine Duration in Europe
Bílková, Jarmila ; Huth, Radan (advisor) ; Holtanová, Eva (referee)
LONG-TERM CHANGES IN CLOUDINESS AND SUNSHINE DURATION IN EUROPE Abstract The aim of this paper is to study long-term changes of two climatological parameters known as sunshine duration (SD) and cloudiness (CC) using several stations data located in Europe in the period 1965 - 2016. This paper is devided into two main parts. First part is paying attention to the literary research, which firstly introduce the chosen climatical variables (SD and CC) and then introduce the issue of the already known long term changes of this variables. Second part of this work is based on practical research. This paper uses a statistical linear regression to find out the seasonal and annual trends in sunshine duration and cloudiness. Data series were obtained from database ECA&D in total from 48 european climatic stations. Klíčová slova: cloud cover, sunshine duration, climate change, trends, Europe
|
|
|
Frequency analysis of precipitation amounts
Rulfová, Zuzana ; Kyselý, Jan (advisor) ; Holtanová, Eva (referee) ; Picek, Jan (referee)
Title: Frequency analysis of precipitation amounts Author: Mgr. Zuzana Rulfová Department: Department of Atmospheric Physics Supervisor: RNDr. Jan Kyselý, Ph.D., Institute of Atmospheric Physics CAS Abstract: This thesis deals with analysing characteristics of mean and extreme precipitation in observations and regional climate models (RCMs) with respect to their convective and stratiform origin. An algorithm for subdivision of precipitation amounts into predominantly convective and stratiform using station weather data is proposed and evaluated. The time series of convective and stratiform precipitation from the Czech Republic over 1982-2010 are used for analysing basic climatological characteristics of precipitation, including extremes, and evaluating RCMs from the ENSEMBLES project. Projected changes of convective and stratiform precipitation in Central Europe (the Czech Republic) are analysed using data from RCM simulations from the EURO-CORDEX project. The last part of the thesis introduces a new statistical model for analysing precipitation extremes. This model takes advantage from knowledge of origin of precipitation extremes. In future climate we could expect more convective and stratiform precipitation amounts in all seasons except summer, when climate models project decline in amounts of stratiform...
|
|
| |
|
|
Uncertainties in regional climate models outputs
Holtanová, Eva ; Kalvová, Jaroslava (advisor) ; Halenka, Tomáš (referee) ; Dubrovský, Martin (referee)
Title: Uncertainties in regional climate models outputs Author: RNDr. Eva Holtanová Supervisor: doc. RNDr. Jaroslava Kalvová, CSc. Department: Dept. of Meteorology and Environment Protection Faculty of Mathematics and Physics Charles University in Prague Present doctoral thesis focuses on the analysis of uncertainties in regional climate model outputs in the area of the Czech Republic. Generally, the uncertainties in model outputs come from inaccuracies of initial and boundary conditions, further from the necessity to parameterize the small scale processes, and the structure of the model, e.g. the choice of numerical schemes or spatial resolution. In case of the simulations of future climate, another source of uncertainty arises. It is the unknown development of forcings that influence the climate system. The analysis in this work focuses on two multi-model ensembles, that come from two international European projects PRUDENCE and ENSEMBLES. The simulated 30-year mean seasonal air temperature and precipitation amounts are used, for the reference period 1961- 1990, and several future time periods. Two techniques were employed to assess the uncertainties. The first one was aimed at dividing the variance of a multi-model ensemble into contributions of regional model, driving global model and emission...
|
|
|
Changes of length of periods with characteristic temperatures
Holtanová, Eva
Title: Changes of lengths of periods with characteristic air temperatures Author: Eva Černochová Department: Department of Meteorology and Environment Protection Supervisor: doc. RNDr. Jaroslava Kalvová, CSc. Supervisor's e-mail address: jaroslava.kalvova@mff.cuni.cz Abstract: Lengths of periods with characteristic air temperatures were derived using two different methods (linear interpolation, robust locally weighted regression) for 10 stations in the Czech Republic and for output data of regional climate models HIRHAM and RCAO in 4 grid points. Averages for a forty-year period (1961-2000) and for a thirty-year period (1961-1990) were computed as well as averages for every decade. Considerable attention was also paid to the analysis of methods used in the research. Most stations showed lengthening of growing season and summer during the twentieth century. Decennary average length of growing season and summer shortened in the years 1971-1980. The comparison of output data of regional climate models HIRHAM and RCAO and measured station data showed that the thirty-year average lengths of growing season and summer estimated by the two models were reasonably accurate approximately half of all cases. The models' estimates were not accurate at all concerning decennary averages. Keywords: robust locally...
|
guest ::
