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Relationship among moisture flux anomalies, extreme precipitation, and floods in central Europe
Gvoždíková, Blanka
Floods associated with extreme precipitation are one of the most serious natural hazards, which produce substantial human and socio-economic losses in central Europe. One way to reduce the impact of flooding is by increasing preparedness with better flood forecasts and warnings, which is not possible without a proper understanding of physical processes leading to a flood hazard. However, frequent research on floods in relation to causal precipitation and synoptic conditions is usually carried out regionally, although some events often affect areas of a size of entire countries or even larger. The thesis was focused exactly on these large-scale precipitation and flood events that occurred in the second half of the 20th century and then until 2013, for which the size of the affected area is as crucial in the extremity assessment as the magnitude of flood discharges or precipitation totals. The extremity indices used for the assessment of extreme precipitation and flood events connected both aspects. The larger area of interest defined within central Europe allowed examining the spatial structure of events, the differences between them, and their relation to conditions in the atmosphere. To connect the extremes of precipitation with extremes in atmospheric conditions, the causal circulation was...
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Relationship among moisture flux anomalies, extreme precipitation, and floods in central Europe
Gvoždíková, Blanka ; Müller, Miloslav (advisor) ; Nissen, Katrin (referee) ; Wypych, Agnieszka (referee)
Floods associated with extreme precipitation are one of the most serious natural hazards, which produce substantial human and socio-economic losses in central Europe. One way to reduce the impact of flooding is by increasing preparedness with better flood forecasts and warnings, which is not possible without a proper understanding of physical processes leading to a flood hazard. However, frequent research on floods in relation to causal precipitation and synoptic conditions is usually carried out regionally, although some events often affect areas of a size of entire countries or even larger. The thesis was focused exactly on these large-scale precipitation and flood events that occurred in the second half of the 20th century and then until 2013, for which the size of the affected area is as crucial in the extremity assessment as the magnitude of flood discharges or precipitation totals. The extremity indices used for the assessment of extreme precipitation and flood events connected both aspects. The larger area of interest defined within central Europe allowed examining the spatial structure of events, the differences between them, and their relation to conditions in the atmosphere. To connect the extremes of precipitation with extremes in atmospheric conditions, the causal circulation was...
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Některé aspekty dynamiky letního monsunu v Asii v reanalyzovaných meteorologických datech
Jajcay, Nikola ; Raidl, Aleš (advisor) ; Mikšovský, Jiří (referee)
The Asian summer monsoon (ASM) is a high-dimensional and highly complex phenomenon affecting more than one fifth of the world population. The intraseasonal component of the ASM undergoes periods of active and break phases associated respectively with enhanced and reduced rainfall over the Indian subcontinent and surroundings. In this thesis the nonlinear nature of the intraseasonal monsoon variability is investigated using the leading Empirical Orthogonal Functions of ERA-40 sea level pressure reanalyses field over the ASM region. The probability density function is then computed in spherical coordinates using the Epaneshnikov kernel method. Three significant modes are identified. They represent respectively (i) the East - West mode with above normal sea level pressure over East China sea and below normal pressure over Himalayas, (ii) the mode with above normal sea level pressure over East China sea (without compensating centre of opposite sign as in (i)) and (iii) the mode with below normal sea level pressure over East China sea (same as (ii) but with opposite sign). The relationship with large-scale forcing is also investigated by stratifying the PCs according to representing indices. The regimes derived from spherical PDFs appear to be opposite under opposite large-scale conditions. EOF technique with...
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