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Singularities in annual cycle of climatic variables, their long-term changes and relationships to atmospheric circulation
Radová, Michaela ; Kyselý, Jan (advisor) ; Kalvová, Jaroslava (referee)
In this thesis a statistical detection of singularities (strong deviations from the smoothed mean annual cycle of a climatic variable) was performed on the basis of mean daily air temperature at the Prague - Klementinum station over the period 1881-2000. A temporal stability of all singularities was investigated, and probabilities of the occurrence of the strongest ones and some of the most often mentioned ones were determined. Long-term changes of occurrence of these singularities and their relationships to atmospheric circulation were analyzed. The results show that the temporal stability (annual recurrence as well as regular occurrence at specific calendar days of a year) cannot be assumed for most singularities. Moreover, some of the singularities found using this procedure can generally be just statistical properties of a chosen sampling without relationships e.g. to circulation conditions. That is why it is not proper to look for singularities tied closely to a specific date and use only one reference period for their detection. Variability of atmospheric circulation is the main source of long-term changes of the occurrence of examined singularities.
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Variability of meteorological processes in stratosphere in relation to vertical ozone profile
Motl, Martin ; Kalvová, Jaroslava (advisor) ; Halenka, Tomáš (referee)
There is studied an influence of dynamical processes in atmosphere on the total ozone and its vertical profile in this work. There are described known atmospherical processes with influence on ozone variability and statistical methods used in the work at first. Then is studied connection between ozone and tropopause height. There are also monitored time trends of ozone and tropopauzse height. There are computed modes of variability for the field of the geopotential in pressure levels from 500 to 10 hPa in the next part of the work and there is studied a statistical connection between computed modes and ozone. There is constructed linear regression model from time trend and computed modes. This model describes considerable part of the ozone variability and there are discussed possibilities of use some similar model for prediction of the total ozone in the resume.
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Changes of length of periods with characteristic temperatures
Černochová, Eva ; Metelka, Ladislav (referee) ; Kalvová, Jaroslava (advisor)
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...
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Klimatická změna a klimatické fluktuace - normály vybraných klimatologických prvků na území České republiky: Zpřesnění scénářů vývoje klimatu na území ČR s přihlédnutím k regionálním změnám v oblasti střední Evropy podle nejnovějších dostupných modelů
Ústav fyziky atmosféry AV ČR, Praha ; Univerzita Karlova v Praze, Matematicko-fyzikální fakulta ; Národní klimatický program České republiky ; Pišoft, Petr ; Dubrovský, Martin ; Mikšovský, Jiří ; Marván, Daniel ; Borák, Matouš ; Raidl, Aleš ; Halenka, Tomáš ; Kalvová, Jaroslava
Zpráva obsahuje výsledků projektu za DP 01 bod A Zpřesnění scénářů vývoje klimatu na území ČR s přihlédnutím k regionálním změnám v oblasti střední Evropy podle nejnovějších dostupných modelů (archivace výstupů nové verze klimatického modelu HadCM3 klimatického centra HCCPR z databáze IPCC, porovnání výstupů HadCM2 a HadCM3 pro období 1961-1990 (historický běh modelů), scénáře změny klimatu v tabelární podobě se zahrnutím a bez zahrnutí vlivu aerosolů, podklady pro publikaci Zpřesněné scénáře změny klimatu v ČR a jejich předpokládané dopady na vodní zdroje, zemědělství, lesní hospodářství a na lidské zdraví) a bod B Odhady změn ve variabilitě a četnosti výskytu vybraných charakteristik teploty vzduchu (výběr metodických postupů wavelet analýzy pro výzkum variability teplotních řad, ověření zvolených postupů wavelet analýzy na vybrané stanici, aplikace zvolených postupů wavelet analýzy na teploty vzduchu měřené na šesti vybraných stanicích ČR, zhodnocení výsledků wavelet analýzy z hlediska variability).
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