Weather and traffic accidents in the Czech Republic, 1979–2020

Theoretical and Applied Climatology - Police records, kept in the form of yearbooks, enabled analysis of the possible relationships between traffic accidents and the weather in the Czech Republic...     

A flow mechanism for layering in a heterogeneous porous medium

The flow of a particle fluid mixture through a heterogeneous permeable material is studied with a view to obtaining characteristic fingerprints for the structures that such flows may exhibit. This flow has a variable density and behaves as a compressible fluid, with the compressibility derived from the variations of the local field variables. Both pressure-sensitive or speed-fluctuation-dependent rheologies are studied in the steady state and a speed-fluctuation-dependent material is studied in a time-dependent analysis. The salient findings are that for a pressure-sensitive material structures normal to the mean flow direction are obtained. For the speed-fluctuation-dependent rheology, the pressure structures are normal to the mean flow, whereas the density structures are aligned with the flow (fingering).Electronic Supplementary Material Electronic Supplementary Material is available in the online version of this article at .     

Flood Events of Selected European Rivers in the Sixteenth Century

The severity and frequency of sixteenth-century floods of the Rhine, the Main, the middle and upper Elbe with its tributaries, rivers of northern and central Italy, the Garonne and rivers in Catalonia and Andalusia are analyzed using documentary evidence. The basic topographical and hydrological characteristics of the rivers investigated as well as the synoptic causes of their flooding during the instrumental period are presented. Different examples of modifications of the run-off process due to anthropogenic activity are discussed. Prevalence in flood occurrence during the second half of the sixteenth century in comparison to the first half is typical for central European and Andalusian rivers (mainly in the 1560s and 1590s) and agrees with the evolution of precipitation patterns. On the other hand, Italian and Catalonian rivers, in part, had a higher occurrence of floods during the first half of the century. Changes in the flooding seasons in both halves of the century are not unambiguous. Results of an analysis on a broader European scale show floods to be a random natural phenomena with limited areal extent defined by the spatial influence of forcing meteorological factors (continuous heavy rains, sudden melting of thick snow cover, etc.). Despite some limitations of documentary evidence, series of reconstructed historical floods are valuable sources of proxy data which can be utilized for the study of the flooding fluctuations in the pre-instrumental period.     

Climatic Variability in Sixteenth-Century Europe and its Social Dimension: A Synthesis

The introductory paper to this special issue of Climatic Change summarizes the results of an array of studies dealing with the reconstruction of climatic trends and anomalies in sixteenth-century Europe and their impact on the natural and the social world. Areas discussed include glacier expansion in the Alps, the frequency of natural hazards (floods in central and southern Europe and storms on the Dutch North Sea coast), the impact of climate deterioration on grain prices and wine production, and finally, witch-hunts.The documentary data used for the reconstruction of seasonal and annual precipitation and temperatures in central Europe (Germany, Switzerland and the Czech Republic) include narrative sources, several types of proxy data and 32 weather diaries. Results were compared with long-term composite tree ring series and tested statistically by cross-correlating series of indices based on documentary data from the sixteenth century with those of simulated indices based on instrumental series (1901-1960). It was shown that series of indices can be taken as good substitutes for instrumental measurements.A corresponding set of weighted seasonal and annual series of temperature and precipitation indices for central Europe was computed from series of temperature and precipitation indices for Germany, Switzerland and the Czech Republic, the weights being in proportion to the area of each country. The series of central European indices were then used to assess temperature and precipitation anomalies for the 1901-1960 period using transfer functions obtained from instrumental records. The statistical analysis of these series of estimated temperature and precipitation anomalies yielded features which are similar to those obtained from instrumental series.Results show that winter temperatures remained below the 1901-1960 average except in the 1520s and 1550s. Springs fluctuated from 0.3°C to 0.8°C below this average. Summer climate was divided into three periods of almost equal length. The first was characterized by an alternation of cool and warmer seasons. The second interval was 0.3°C warmer and between 5 and 6% drier than in the 1901–1960 period. It is emphasized that this warm period included several cold extremes in contrast to the recent period of warming. Summers from 1560 were 0.4°C colder and 4% more humid. Autumns were 0.7°C colder in the 1510s and 20% wetter in the 1570s. The deterioration of summer climate in the late sixteenth century initiated a second period of enlarged glaciers in this millennium (the first having been in the fourteenth century) which did not end until the late nineteenth century.An analysis of forcing factors (solar, volcanic, ENSO, greenhouse) points only to some volcanic forcing. In order to understand circulation patterns in the sixteenth century in terms of synoptic climatology, proxy information was mapped for a number of anomalous months. Attempts to compare circulation patterns in the sixteenth century with twentieth-century analogues revealed that despite broad agreements in pressure patterns, winters with distinct northeasterly patterns were more frequent in the sixteenth century, whereas the declining summer temperatures from the mid-1560s seem to be associated with a decreasing frequency of anticyclonic ridging from the Azores' center of action towards continental Europe. The number of severe storms on the Dutch North Sea coast was four times greater in the second half of the century than in the first. A more or less continuous increase in the number of floods over the entire century occurred in Germany and the Czech lands. The Iberian peninsula and the Garonne basin (France) had the greatest number of severe floods in the 1590s.The analysis of the effects of climate on rye prices in four German towns involved a model that included monthly temperatures and precipitation values known to affect grain production. The correlation with rye prices was found significant for the entire century and reached its highest values between 1565 and 1600. From the 1580s to the turn of the century wine production slumped almost simultaneously in four regions over a distance of 800 kilometers (Lake Zurich to western Hungary). This had far-reaching consequences for the Habsburg treasury and promoted a temporary shift in drinking habits from wine to beer. Peasant communities which were suffering large collective damage from the effects of climatic change pressed authorities for the organization of witch-hunts. Seemingly most witches were burnt as scapegoats of climatic change.     

Stratigraphisch-Paläontologische Hinweise zum Ablauf tektonischer Ereignisse in den Ostalpen während der Kreidezeit

Zusammenfassung Im Hinblick auf den zeitlichen Ablauf orogener Ereignisse und ihre paläogeographischen Auswirkungen werden vorwiegend mikropaläontologische Resultate referiert, die ihren sehr raschen Ablauf während nur ein bis zwei Faunenzonen bzw. innerhalb einer Unterstufe wahrscheinlich machen. Dies gilt für die Austrische Phase innerhalb des Gault, die Vorgosauische Phase innerhalb des höheren Turon und eine baugeschichtlich sehr bedeutsame Intragosauische Phase im Unteren Ober-Campan. Im Verlaufe oder unmittelbar nach diesen tektonischen Ereignissen kommt es vorgosauisch und intragosauisch auch zur Verlandung, was durch Süßwasser-Fossilien und durch Landsaurier-Reste bewiesen werden kann. Die neu erfolgende marine Ingression bringt dann wieder marine Mikrofaunen, deren Altersunterschied zu jenen jüngsten marinen Faunen vor der jeweiligen tektonischen Phase erstaunlich gering ist. Es gibt jedoch in den Kreideschichten der Ostalpen kein Profil und keine Aufschlußfolge, wo all diese Umstände zusammen nachweisbar sind. Vielmehr bedarf es, infolge der Lückenhaftigkeit der Überlieferung, einer Kombination paläontologischer, stratigraphischer, paläogeographischer, petrographischer und tektonischer Studien in einem größeren Umkreis.

---

The velocity of orogenetic events and their palaeogeographic effects are discussed from a point of view which is supported by micropalaeontological studies. These studies enable to prove the beginning and end of the orogenetic events within one or two faunistic zones or stratigraphic substages. This is demonstrated for the Austric orogenetic phase within the Gault (Late Aptian — Albian times), for the Pregosavian orogenetic phase within the Upper Turonian, and for an important Intragosavian orogenetic phase within early Upper Campanian times, too. During the movements of the Pregosavian and the Intragosavian phase or immediately following to them the seafloor emerged. Continental environments are confirmed by freshwater fossils and remains of terrestric reptiles. Succeeding new marine ingression brings new marine microfossils demonstrating that there is only a slight difference in geological age to the marine fauna living just before the gone orogenetic phase. Unfortunately there is no locality in the Eastern Alps, where all these events could be demonstrated in continuously sedimented Cretaceous beds. The fragmentarity of the geological evidence, however, enforces a combination of palaeontological, stratigraphical, palaeogeographical, petrological, and tectonical studies in more expanded areas.

---

Résumé L'auteur, envisageant le déroulement temporel d'événements orogéniques et leurs répercussions paléogéographiques fait état avant tout de résultats micropaléontologiques qui rendent vraisemblable leur déroulement très rapide pendant seulement une à deux zones fauniques, c'est-à-dire à l'intérieur d'un sous-étage. Ceci s'applique à la phase Austrique pendant le Gault, à la phase pré-Gosau pendant le Turonien supérieur et à une phase Intra-Gosau, au début du Campanien supérieur, très importante du point de vue de l'histoire tectonique. Au cours de ces événements tectoniques ou immédiatement après, survient, au cours du pré-Gosau et de l'intra-Gosau, une émersion qui peut être prouvée par des fossiles limniques et par des restes de sauriens terrestres. L'ingression marine qui lui fait suite, ramène à nouveau des microfaunes marines, d'âge étonnament peu différent de celui des plus jeunes faunes marines qui ont vécu avant chaque phase tectonique. Toutefois, il n'existe, dans le Crétacé des Alpes orientales, aucun profil ni série d'affleurements où tous ces faits puissent être démontrés en même temps. Bien plus, le nourissage sédimentaire impliquant des lacunes, il faut combiner les études paléontologiques, stratigraphiques, paléogéographiques, pétrographiques et tectoniques dans une vue plus large.

---

, , , . . - , , 1–2 . Austrische Gault'e, Vorgosauische Intragosauische . , , . , . , , . , , , .

     

Über die Perm-Trias-Grenze in Ostgrönland und Über die Problematik Stratigraphischer Grenzen

Zusammenfassung Ostgrönland ist eine der wenigen Gegenden der Erde, wo das oberste marine Perm (mitCyclolobus) konkordant von Schichten der ältesten Trias (mitOtoceras undGlyptophiceras, später dazuOphiceras) überlagert wird. Brachiopoden und Bryozoen von permischem Charakter koexistieren noch mit den ältesten Triasammoniten, so daß die Grenze zwischen den beiden Systemen nur künstlich festgelegt werden kann.Vorläufige Mitteilung; die ausführlichen Resultate erscheinen in den Meddelelser om Grønland.     

Buchbesprechungen

Ohne Zusammenfassung     

Buchbesprechungen

Ohne Zusammenfassung