National Repository of Grey Literature 17 records found  1 - 10next  jump to record: Search took 0.00 seconds. 
Effects of solar activity in power-distribution grids
Výbošťoková, Tatiana ; Švanda, Michal (advisor) ; Hejda, Pavel (referee)
Eruptive events on the Sun have an impact on immediate cosmic surround- ings of the Earth. Through induction of electric current also affect Earthbound structures such as the electric power distribution networks. Inspired by recent studies we investigate the correlation between the disturbances recorded by the Czech electric-power distributors with the geomagnetic activity represented by the K index. We found that in the case of the datasets recording the disturbances on the power lines with the high and very high voltage levels and disturbances on elec- trical substations, there was a statistically significant increase of failure rates in the periods of maxima of geomagnetic activity compared to the adjacent minima of activity. There are hints that the disturbances are more pronounced shortly after the maxima than shortly before the maxima of activity. Our results provide hints that the geomagnetically induced currents may af- fect the power-grid equipment even in the mid-latitude country in the middle of Europe. A follow-up study that includes the modelling of geomagnetically induced currents is needed to confirm our findings. The second part of our research includes modelling of geoelectric field using one-minute geomagnetic measurements from Intermagnet database. We applied this model to the long-term...
The influence of solar activity on failure rate of components of Czech power-distribution network
Výbošťoková, Tatiana ; Švanda, Michal (advisor) ; Mošna, Zbyšek (referee)
We analyse the impact of solar activity on Czech power grid. Massive solar flares are responsible for the formation of spaceweather and have a certain impact on technological infrastructures on the Earth and in its surroundings. We elaborated this issue and studied possible effects of spaceweather events on failure rate recorded in Czech power grid. The basis of the practical part is a program that processes the data recording the disturbances on power grid in the Czech Republic obtained by ČEPS (Czech Transmission System Operator) and compared those with the measured values of geomagnetic activity from Budkov station in Šumava by the statistical analysis methods. Our study revealed that there possibly exists some connection between the intensity of solar activity and disturbances in the Czech eletrical power grid. It turns out that the number of faults on the grid during the period of increased solar activity is appreciably higher than in the period of lower solar activity. Our work contributes to the propagation of awareness of disturbances in the Czech electrical power grid that can also arise due to solar activity
Application of Geomagnetic Data and Solar Physics for Education of Sciences in Secondary School
BAYER, Tomáš
This docement summarizes current geophysiscs and solar physics knowledge collection and applies it in grammar school education. Document explains significance of Earth geomagnetic field for whole biota and their evolution and includes current knowledge of geophysics and solar physics to the Programme for Secondary General Education (Grammar Schools). The document introduces actual findings of solar physics and geophysics (especially geomagnetism) to the educational area Man and Nature containing synthetic education of biology and geosciences. The main method of this document is comparison and explanation of solar physics satellite data, explanation of solar disc records and solar wind time series. This data have been compared by Czech national Geomagnetic observatory (IAGA code BDV) variograms and enables pupils to process satellite and observatory real-time data.
Possible correlations between geomagnetic activity and global air temperature
Střeštík, Jaroslav
Annual values of the geomagnetic activity indices aa have been compared with the annual mean values of global air temperature during 1850-2012. Despite of a big noise level a significant positive correlation takes place. However, it only reflects a very similar long-term change occurring in both investigated quantities, which must not have a common origin. Short periodical changes with periods of years or decades are at both quantities quite different and their correlation is negligible. When shorter parts with the length of about some decades have been compared, resulting correlations were different. The significant correlation for the whole period is therefore not persistent. No influence of the geomagnetic activity on global temperature in shorter time dimensions has been proved and therefore it is not possible to use any estimate of a possible course of the geomagnetic activity for a prediction of the global temperature in the future. Using the temperature data from the individual stations instead of the global ones different correlations can be obtained but even these are not persistent. The same result will follow using any other selection of shorter intervals.
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
Frequency of worldwide terroristic acts since the end of sixties
Střeštík, Jaroslav ; Grigoryev, P. ; Mikulecký, M.
The analysis was performed on the eight geopolitical areas (Africa, Eastern Europe, Middle East and Persian Gulf, North America, Central and South America, South-East Asia and Oceania, South Asia, and Western Europe), on their sum and on the solar and geomagnetic variables. There is a good correlation between frequencies of terroristic attacks in different regions. There is also a strong connection between terroristic attacks on one side and some heliogeophysical factors on the other side. All connections are different for different regions and external factors, respectively. Nevertheless, most of them are significant. The relationship to factors describing geomagnetic activity is a little higher than that for factors of solar activity.
Salmonellosis and some solar and geomagnetic parameters
Střeštík, Jaroslav ; Mikulecký Jr., M. ; Mikulecký, M.
Salmonellosis is a common infection in our country and therefore it is necessary to investigate which factors contribute to the increase of its incidence. The influence of tidal acceleration has been investigated earlier and some semilunar variations have been found. The influence of heliogeophysical factors was not investigated though laboratory studies proved some connections. In this contribution daily numbers of hospital admissions at the Infectology Clinic in Bratislava from 2005-2006 have been used. The incidence of salmonellosis is considerably higher in summer than in winter, the maximum of incidence appears after the maximum of air temperature with a time shift more than one month. The higher geomagnetic activity contributes to higher incidence of salmonellosis too. Its influence is more significant than that of solar activity.
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.
Comparison of solar and geomagnetic effects on the atmospheric circulation variability modes
Huth, Radan ; Pokorná, Lucie ; Bochníček, Josef ; Hejda, Pavel
The shapes, spatial extent, and intensity of modes of low-frequency variability of atmospheric circulation in the Northern Hemisphere in winter are significantly affected by the phase of the 11-yr solar cycle. Here we extend the analysis to the geomagnetic activity, and compare the results with the solar activity.
Variations with periods near 1.3 year in solar and geomagnetic activity
Střeštík, Jaroslav
The period about 1.3 years, found some time ago in solar wind velocity and in some biological data, is in geomagnetic aktivity prezent only in a short interval after 1990 a in leader extent around 1942. Other periods in the vicinity appear only sporadically and are much weaker. A connection with the solar cycle (even – odd) was not found. In solar acitvity these periods do not appear at all.

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