On the dependence of life evolution on geotectonic stages     

Radan Květ 《GeoJournal》1995,37(4):413-417

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A new hydrogeochemical and geotectonical interpretation of the Lake Nyos disaster in Cameroon     

Radan Květ 《GeoJournal》1991,25(4):367-370

Conclusion The gas eruption in Lake Nyos allows solely a deep inorganic origin of the CO₂, and CO₂ ascent along intersecting ruptures to be considered. Enormous gas volumes can be liberated from ascension paths with voids in the deep sections of the Earth's crust rather than from the water-dissolved phase (a lake) on the Earth's surface. In this case, rupture activity rather than volcanic activity should be involved. Similarly to volcanic activity, other events are also associated with open ruptures in the Earth's crust. No interrelations exist between the single phenomena. One of them consists in the ascent of CO₂ with no relation to magma. Earthquakes, too, are associated with ruptures. Even a very slight tremor of the Earth's crust can contribute to the liberation of deepseated compressed CO₂. However, disturbing the equilibrium of the water-column pressure and the compressed gas can result in an eruption even with no external impetus, e. g. an earthquake.  相似文献   

Book reviews     

Konrad Murr  Jaromir Demek  Athanstios P. Kamarianos  Xanthippos N. Karamanlis  Radan Květ  Ludwig Ellenberg  Anton Gosar  Jörg Stadelbauer  Wolf Tietze 《GeoJournal》1994,34(3):332-336

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Combined solar and QBO effects on the modes of low-frequency atmospheric variability in the Northern Hemisphere     

Radan Huth  Lucie Pokorn  Josef Bochní ek  Pavel Hejda 《Journal of Atmospheric and Solar》2009,71(13):1471-1483

We examine joint effects of the solar activity and phase of the quasi-biennial oscillation (QBO) on modes of low-frequency variability of tropospheric circulation in the Northern Hemisphere in winter. The winter months (December–March) are stratified by the solar activity into two (below/above median) classes, and each of these classes is subdivided by the QBO phase (west or east). The variability modes are determined by rotated principal component analysis of 500 hPa heights separately in each class of solar activity and QBO phase. Detected are all the modes known to exist in the Northern Hemisphere. The solar activity and QBO jointly affect the shapes, spatial extent, and intensity of the modes; the QBO effects are, however, generally weaker than those of solar activity. For both solar maxima and minima, there is a tendency to the east/west phase of QBO to be accompanied by a lower/higher activity of zonally oriented modes and increased meridionality/zonality of circulation. This means that typical characteristics of circulation under solar minima, including a more meridional appearance of the modes and less activity of zonal modes, are strengthened during QBO-E; on the other hand, circulation characteristics typical of solar maxima, such as enhanced zonality of the modes and more active zonal modes, are more pronounced during QBO-W. Furthermore, the zonal modes in the Euro-Atlantic and Asian sectors (North Atlantic Oscillation, East Atlantic pattern, and North Asian pattern) shift southwards in QBO-E, the shift being stronger in solar maxima.  相似文献   

The day-to-day effects of strong geomagnetic disturbances on the North Atlantic Oscillation in the winter periods of years 1951–2003     

Bochníček  Josef  Šimkanin  Ján  Hejda  Pavel  Huth  Radan 《Studia Geophysica et Geodaetica》2019,63(3):455-464

The day-to-day effects of the strong geomagnetic disturbances on geopotential heights (GPH) in the winter lower atmosphere were described in many papers in the beginning of 1970s. These works focused on the North-East Pacific, while the North Atlantic was until now omitted. Our aim is therefore to investigate the possible effect of strong geomagnetic disturbances on the lower atmosphere GPH changes over the winter North Atlantic on the day-to-day time scale, represented by the daily index of the North Atlantic Oscillation (NAO). The investigated intervals are winter periods (December-March) of 1951–2003. The daily NAO average values in 3-day intervals before and after the disturbance onsets are compared. The graphs of NAO differences are complemented by the maps of GPH differences. The NAO response to geomagnetic disturbance, as registered on the day-to-day time scale, also shows a change in its behaviour around the year 1970. This response reaches its highest values in the years 1951–1969, usually 2–5 days following the onset of geomagnetic disturbances. Intensity of the response depends on the disturbance intensity (the largest differences were associated with extremely strong disturbances).

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The behaviour of the mean energetic level in time and space: Persistence,autocorrelations, links to standard levels     

Radan Huth 《Studia Geophysica et Geodaetica》1995,39(4):449-465

Summary The variances, persistence, and spatial autocorrelations of the basic quantities at the mean energetic level (MEL) as well as the links between the MEL and standard isobaric levels are investigated. The statistics obtained for the MEL are compared with those for height and temperature at the 500 and 300 hPa levels. The behaviour of most quantities at the MEL does not show any peculiarity making it substantially different from isobaric levels. The only quantity at the MEL, not closely correlated with any variable at adjacent standard levels, appeared to be the pressure.  相似文献