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Comparison of lightning detection networks over Czechia
Pacovská, Lucie ; Popová, Jana (advisor) ; Müller, Miloslav (referee)
This thesis focuses on ground-based lightning detection which is important since lightning discharges still cause casualties yearly worldwide. The thesis provides description of several ground-based lightning detection networks and an analysis of lightning data of three lightning detection networks covering the Czech Republic during 2015 - 2021. Specifically, the data of the World Wide Lightning Location Network (WWLLN), the amateur network Blitzortung and the European network EUropean Cooperation for LIghtning Detection (EUCLID) are investigated. The thesis examines the spatial and temporal characteristics of lightning discharges from the three detection networks, the relationship between lightning discharges and land cover from CORINE Land Cover data, and the relationship of lightning discharges with types of weather situations based on the Czech Hydrometeorological Institute (CHMI) data. The results show that there is not much difference in the temporal and spatial characteristics of lightning discharges among the three detection networks. The relationship between lightning activity and land cover is the same for the three networks. Unlike the relationship between lightning activity and land cover, the relationship between lightning activity and weather types is in good agreement among the...
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State of the art on lightning activity induced by volcanism
Tesař, Matouš ; Popová, Jana (advisor) ; Křížek, Marek (referee)
The thesis presents a state of the art of existing knowledge and findings related to the lightning inducted by volcanic activity. First the thesis briefly characterizes lightning which occurs in thunderstorms. The chapter also presents mechanisms of lightning occurrence and methods of lightning detection. The main part of the thesis contains a literature review on the characteristics of lightning which occurs in relation to volcanic activity. It also provides classification of volcanic lightning and mechanisms of its occurrence. Furthermore, the chapter describes methods which are used to detect volcanic lightning. It also contents methods of investigation of volcanic lightning and laboratory experiments, which aim at deepening theknowledge on this phenomenon. Moreover, the chapter also provides a brief outline of expected future research on volcanic lightning. The thesis presents several ways by which volcanic lightning affects the Earth's atmosphere and surface, and the affected volcanic ash particles. Based on findings provided by the literature, the thesis discusses and compares lightning produced during in thunderstorms with volcanic lightning. Key words: lightning, volcanism, state of the art, detection
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Changes of rainfall-runoff regime in selected mountain areas of the Czech Republic with respect to their location and side exposure Preparation of precipitation datasets
Kalista, Tomáš ; Kliment, Zdeněk (advisor) ; Popová, Jana (referee)
The main topic of bachelor thesis is the evaluation of precipitation in selected mountains of Czechia. Precipitation regimes in mountain areas are very variable and depend on many factors, which are properly described in the research part of the work - synoptic situations, altitude, mountain orientation. These factors can lead to inequality in distribution of precipitation, which may result in windward and leeward effect or rain shadow. The main goal of the study is to analyze the frequency of synoptic situations that can clarify rainy and dry mountain areas. The work also contains analyzes of average annual totals for ten-year to twenty-year periods in selected mountain areas using cartograms and graphs of precipitation totals in connection with station altitudes. The secondary goal of the thesis is the preparation and completion of dataset files for following studies. Using the above methods, the strength of the windward and leeward effect in most of the studied mountains was clarified, which is related to the findings on the predominant influence of cyclonic synoptic situations coming from the west. Key words: precipitation, synoptic situations, windward and leeward effect, rain shadow, major mountains areas of Czechia
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Lightning activity prediction using a numerical weather prediction model
Uhlířová, Iva ; Popová, Jana (advisor) ; Zacharov, Petr (referee)
Lightning activity is considered a severe meteorological hazard that needs to be studied, monitored as well as predicted. This thesis focuses on the prediction of lightning activity by the Lightning Potential Index (LPI) in the COSMO numerical weather prediction (NWP) model that comprises 1- and 2-moment (1M and 2M, respectively) cloud microphysical schemes. The objective of this thesis is to investigate the correlation between the predicted lightning activity and the detected one (by the European network for lightning detection EUCLID). Events of the years 2018 and 2019 that recorded significant lightning activity over Czechia are considered for the analyses. For the first time over Czech region, the prognostic values of LPI calculated for each event are verified. In particular, the spatio- temporal distribution of the predicted vs. detected lightning activity is evaluated. Both spatial characterizations and diurnal course of detected lightning activity correspond well to the theoretical knowledge. Thus, spatial (horizontal) and temporal approaches are applied to verify the lightning activity prediction. The results of this thesis successfully verify the LPI prognostic values both in space by comparing the LPI values with the proximity of detected lightning flashes, and in time by contrasting the...
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Relationship between weather types and lightning discharges in Central Europe
Pacovská, Lucie ; Popová, Jana (advisor) ; Müller, Miloslav (referee)
This thesis aims at describing a lightning discharge and the lightning activity detection with an emphasis put on the World Wide Lightning Location Network (WWLLN). It also investigates possible relationships between the lightning discharge data from the WWLLN and the weather types given by the Weather type catalogue, which is published by the Czech Hydrometeorological Institute (CHMI), in Central Europe. In the state of the art, cloud electricity and lightning discharges as well as their detection and network detection are presented followed by a detailed description of the WWLLN, examples of outputs which are provided by WWLLN to the public, and some of the studies processing the data of WWLLN at global and European level mostly dealing with the network efficiency. This thesis uses the WWLLN data during 2017 - 2019 and the weather types provided by the CHMI. It displays the temporal and spatial distribution of the WWLLN data and mainly the results of testing the hypothesis whether there is a relationship between lightning discharges and weather types (or not) by using the two-tailed binomial test. The results show that for the weather types B (low pressure trough), NWa (northwestern anticyclonal situation) and Wal (western anticyclonal summer situation) the probability that at least one...
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Mediterranean Cyclones and Their Influence on the Weather in Europe
Ashby, Patrik ; Müller, Miloslav (advisor) ; Popová, Jana (referee)
This is a research paper considering Mediterranean cyclones, their genesis, and trajectories of motion in the context of extratropical cyclones. Attention is mostly given to the presentation of Mediterranean cyclones, their spatial distribution and impact on weather in Europe. Cyclones from the Mediterranean region proceed through Europe following certain tracks where the Vb pathway, heading from the Gulf of Genoa towards the northeast, is the most compelling. Such cyclones affect weather especially in Central and Eastern Europe. The average number of Vb cyclones in Europe is roughly two to four events a year with an average lifetime of 3,1 days. Cyclones from the Mediterranean often have to cross the Alpine mountain range through the process of segmentation. Extreme and long-lasting precipitation falling from the cold sector of Vb cyclones is furthermore enhanced by low mountain ranges of Central Europe. Vb cyclones are also responsible for several significant flood events in Europe as well as heavy snowfall in the Apennines, eastern Alps and other mountain ranges. Keywords: extratropical cyclone, Mediterranean, pathway Vb, retrogressive, extreme precipitation, flooding
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Lightning activity prediction using a numerical weather prediction model
Uhlířová, Iva ; Popová, Jana (advisor) ; Zacharov, Petr (referee)
Lightning activity is considered a severe meteorological hazard that needs to be studied, monitored as well as predicted. This thesis focuses on the prediction of lightning activity by the Lightning Potential Index (LPI) in the COSMO numerical weather prediction (NWP) model that comprises 1- and 2-moment (1M and 2M, respectively) cloud microphysical schemes. The objective of this thesis is to investigate the correlation between the predicted lightning activity and the detected one (by the European network for lightning detection EUCLID). Events of the years 2018 and 2019 that recorded significant lightning activity over Czechia are considered for the analyses. For the first time over Czech region, the prognostic values of LPI calculated for each event are verified. In particular, the spatio- temporal distribution of the predicted vs. detected lightning activity is evaluated. Both spatial characterizations and diurnal course of detected lightning activity correspond well to the theoretical knowledge. Thus, spatial (horizontal) and temporal approaches are applied to verify the lightning activity prediction. The results of this thesis successfully verify the LPI prognostic values both in space by comparing the LPI values with the proximity of detected lightning flashes, and in time by contrasting the...
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