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Normality Testing of some Elements of Climate
Jelínek, Petr ; Antoch, Jaromír (referee) ; Huth, Radan (advisor)
Normality of daily temperature is often presumed in climatology. This study aims to verify the adequacy of such a model and possibly design a better one. A set of 20th century temperature data from all parts of Europe is examined. An effort is made to find out, whether regional differences in temperature distribution exist. Chapter 2 describes the preliminary trasformation of the data. In Chapter 3, several normality tests are conducted, based on both higher order statistical moments and EDF goodness-of-fit. Chapter 4 introduces finite normal mixtures, Engelman-Hartigan test and an iterative EM algorithm are applied. Chapter 5 summarizes the results.
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Long term variability of the relationshops between atmospheric circulation and surface climate elemets
Beranová, Romana ; Huth, Radan (advisor) ; Halenka, Tomáš (referee) ; Metelka, Ladislav (referee)
The stability of the relationships between atmospheric circulation and the surface climatic variables is an important precondition to construct scenarios of climate change by statistical methods. The aim of the work is therefore to examine if and how the relationships between atmospheric circulation (characterized by geopotenial heights of 500 hPa level) and surface climatic elements (mainly temperature and precipitation) are changing in European region and in the Czech Republic. The relationship between the NAO index and both temperature and precipitation were analysed for long period (1901-99) at 29 resp. 27 European stations. The NAO index strong influences climate in Europe. However, the relationships were changing in time. The course of 31-years running correlation differs between different European regions and different seasons. The circulation modes were identified in geopotential heights of 500 hPa level by rotated principal component analysis for period 1958-98. The climate in Europe is influenced by NAO, EA, EU1, EU2 and NA mode. The variability of the relationships was represented by 15-year running correlations at more than 100 European stations. The regions with similar courses of running correlations were identified by cluster analysis (PAM method). Despite the considerable variability of the...
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The effect of high long-lasting solar/geomagnetic activity on pressure fields in the winter northern lower atmosphere
Bochníček, Josef ; Davídkovová, Hana ; Hejda, Pavel ; Huth, Radan
The effect of high long-lasting solar/geomagnetic activity on stratospheric and tropospheric pressure distributions was investigated in the winter Northern Hemisphere. The analysis concerns winter period (December 1 – March 30) in 1952-2003. Solar activity is characterized by 30 day means of R number, geomagnetic activity by 30 day means of daily sum of Kp index. Stratospheric and tropospheric pressure distributions are described by 30 day mean anomalies in geopotential height (GPH) at 50 hPa/500 hPa. GPH anomalies are computed as the difference between the long-term 30 day averages (covering 33 year period, 1970-2003) and actual 30 day averages. Data are taken from the NCEP/NCAR reanalysis
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The influence of geomagnetic activity on the course of stratospheric warming
Davídkovová, Hana ; Bochníček, Josef ; Hejda, Pavel ; Huth, Radan
The temperature of the winter polar lower stratosphere is affected except the solar activity and atmospheric circulation by the geomagnetic activity as well. Plausible physical mechanism for its effect was described by Arnold and Robinson. According to this paper, warming in the lower thermosphere caused by geomagnetic activity produces the reduction of blending mid and high latitude air masses. In consequence of this reduction the temperature of solar insulated region (polar lower stratosphere)decreases. The aim of this work is to verify functionality of such mechanism.
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