X-Ray and optical observations of the X-ray source EX0020528+1454.8

We present preliminary results of the EXOSAT X-ray observations and quasisimultaneous and simultaneous optical photometry of the X-ray source EX0020528+1454.8=1E0205+149 found independently as an serendipitous source both with Einstein and EXOSAT satellites. The optical counterpart is a pair of dMe stars. Our results indicate that the object is variable both in X-rays and optical wavelenghts, and probably belongs to dMe flare stars.Paper presented at the IAU Colloquium No. 93 on Cataclysmic Variables. Recent Multi-Frequency Observations and Theoretical Developments, held at Dr. Remeis-Sternwarte Bamberg, F.R.G., 16–19 June, 1986.     

Parametric versus non-parametric estimates of climatic trends

Summary Two methods of estimation of the trend magnitude are compared: the parametric one (least-squares regression) with the non-parametric one (median of pairwise slopes). The comparison is carried out for seasonal and annual trends of ten climatic variables at a network of stations in the Czech Republic. We show that the difference between the two trend estimates is very small, falling well within the 95% confidence limits of the parametric estimate. The magnitude of the difference does not depend on the degree of normality of the distributions, with the exception of two variables, maximum temperature and precipitation, for which a slight dependence is observed. As a by-product, the normality of seasonal and annual means of the climatic variables is evaluated by the Kolmogorov-Smirnov one-sample test.     

Changes of atmospheric circulation in central Europe and their influence on climatic trends in the Czech Republic

This work deals with the influence of changes of atmospheric circulation on observed trends of 11 climatic elements at 21 stations in the Czech Republic in the period 1961–1998. Atmospheric circulation in central Europe is described by the German (Hess-Brezowsky) and Czech-Slovak (Brádka’s) subjective catalogues of synoptic types. In the study period there is a strong downward trend in the occurrence of anticyclonic types in Brádka’s catalogue in all seasons, this trend being most prominent in autumn. Westerly and northwesterly types become more frequent in autumn and winter, less frequent in spring and summer under both classifications. In the Hess-Brezowsky catalogue, the occurrence of anticyclonic types increases in winter, spring, and summer. To assess the effect of circulation changes on observed climate trends we have used the method of “hypothetical” seasonal trends that are calculated from a daily series, constructed by assigning the long-term monthly average of the given climatic element under a specific circulation type to each day classified with this type. The ratio of these circulation-conditioned trends and observed seasonal trends shows that changes in atmospheric circulation are the primary cause of massive winter warming and autumn cooling, which is connected with increasing precipitation and humidity. Summer climate trends are unrelated to changes in atmospheric circulation. Simultaneous use of more circulation classifications for the detection of climatic changes is highly recommended, as the long-term circulation trends depend on the catalogue applied.     

Aboveground Growth and Competition in Forest Gap Models: An Analysis for Studies of Climatic Change

Gap models have been used extensively in ecological studies of forest structure and succession, and they should be useful tools for studying potential responses of forests to climatic change. There is a wide variety of gap models with different degrees of physiological detail, and the manner in which the effects of climatic factors are analyzed varies across that range of detail. Here we consider how well the current suite of gap models can accommodate climatic-change issues, and we suggest what physiological attributes and responses should be added to better represent responses of aboveground growth and competition. Whether a gap model is based on highly empirical, aggregated growth functions or more mechanistic expressions of carbon uptake and allocation, the greatest challenge will be to express allocation correctly. For example, incorporating effects of elevated CO₂ requires that the fixed allometry between stem volume and leaf area be made flexible. Simulation of the effects of climatic warming should incorporate the possibility of a longer growing season and acclimation of growth processes to changing temperature. To accommodate climatic-change factors, some of the simplicity of gap models must be sacrificed by increasing the amount of physiological detail, but it is important that the capability of the models to predict competition and successional dynamics not be sacrificed.     

A new view on neotectonics

Conclusion Neotectonics — the discipline examining the youngest history of the Earth in terms of geotectonics — should be complemented by aspects based on other geological sciences (geochemistry, geophysics) as well as geography and geodesy. From the viewpoint of the Earth's history, neotectonics can be regarded as a discipline studying, above all, the Earth's crust and the changes that occurred there in the time span from the Badenian to the Recent. For this reason, the last phase of the Alpine geotectonic stage, which extended from the Oligocene to the base of the Lower Badenian, should be termed pre-neotectonics.     

The behaviour of the mean energetic level in time and space: Theoretical background and basic characteristics

Summary The behaviour of the mean energetic level (MEL) in space and time is investigated. The basic meteorological quantities (pressure, height, density) and the quantities, playing an important role at the MEL were computed over Europe and the North Atlantic for a 1-year period on the basis of 500 and 300 hPa height and temperature data. The daily maps prove the MEL to be consistent both in time and space. The means, and amplitudes and phases of the annual variation of the quantities at the MEL are presented. It is shown that neglecting the influence of the low tropopauses (below 300 hPa) does not affect the computations significantly.     

The dependence of animal evolution on geotectonic stages and the 2n model

Conclusions In terms of synergetics, animal evolution necessarily seems: to be dependent on the evolutional stages of the Earth, ie on the geotectonic stages and their phases. The detailed causes of and interrelations between the extinction of certain species: and the evolution of new superior types of organisms on the one hand and the phases of geotectonic stages on the other hand still remain to be examined. Undoubtedly this is a task for paleontologists whose attention should focus on additional non-traditional investigations. From a philosophical viewpoint it seems noteworthy that, in the field of geosciences, we again arrive at the significance of the role of numbers as suggested by classical philosophers, eg Pythagoras or Plato, more than 2,000 years ago. As a matter of fact, Plato, in his work called Thimaios, even derived the 2ⁿ and 3ⁿ models as basic models to be used for examinations of the Earth.     

Assessing performances of pattern informatics method: a retrospective analysis for Iran and Italy

Pattern informatics (PI) algorithm, which was introduced at the beginning of past decade, uses instrumental earthquake catalogs to investigate the time-dependent rate of seismicity in the study area and, based on the information from past events, calculates the probabilities for the occurrence of future large earthquakes. The main measure in this method is the number of events above a specified magnitude threshold M _c that is counted over a gridded area. PI has been applied in several regions of the world and different variants of the method have been developed over the past decade. Hence, the problem of formally evaluating and comparing the performances of the different PI variants needs to be addressed from an operational perspective, in order to identify the preferred application scheme and as well as to improve the performances of the method. In this study, PI is applied for the first time to the retrospective analysis of the earthquake catalogs of Iran and Italy, so as to check whether this method could forecast the past large events in these two regions with different level of data completeness and complex seismotectonic setting. The original PI algorithm and one of its modified variants, as well as the relative intensity (RI) model, are used to check the stability and statistical significance of the obtained results. In order to assess and compare the obtained results, the performances of the different PI variants are analyzed considering different evaluation strategies, which turn out to provide significantly different scores even for the same algorithm variant. We show that a critical point in the assessment of the obtained results is related with the definition and quantification of the space uncertainty of the issued forecasts, that is, with the extent of the territory where large earthquakes are to be expected. Accordingly, we emphasize the need for an appropriate definition of the evaluation strategies, clearly and unambiguously indicating the area where a large earthquake has to be expected. The study shows that, with respect to application in Iran and Italy, the performances of PI algorithm (both original and modified variants) are highly dependent on the selected evaluation strategy and do not provide better information than the simple RI model, which does not account for temporal properties of seismicity evolution. The overall performances can be improved by introducing specific thresholds that discard the less active cells; however, being based on some posterior optimization, a rigorous prospective testing is required to assess the forecasting capability of the method. In this paper, we aim to set up the rules for such testing, including advance definition of the evaluation strategy.     

Organic matter governs N and P balance in Danube Delta lakes

The transformation of dissolved inorganic nitrogen (DIN) and soluble reactive phosphorous (SRP), and the release of dissolved organic and particulate N and P, were analyzed in two lake complexes (Uzlina–Isac and Puiu–Rosu–Rosulet) of the Danube Delta wetland during flood conditions in May and at low water level in September 2006. The Uzlina–Isac complex was hydrologically tightly-connected with the Danube River and was flushed with river-borne nutrients and organic matter. These lakes acted as effective transformers for nutrients and produced large amounts of fresh biomass, that promoted the excretion of dissolved organic N and P during active growth. Biomass breakdown created particulate matter (<0.45 μm), which was widely liberated during low flow in the fall. The Puiu–Rosu–Rosulet complex was characterized by a more distant position to the Danube and proximity to the Black Sea, and received dominantly transformed organic compounds from the flow-through water and vast vegetation cover. Due to reduced nutrient input, the internal production of organic biomass also was reduced in these more remote lakes. Total N and P export from the lake nearest to the shelf was governed by dominantly dissolved organic and particulate compounds (mean 58 and 82%, respectively). Overall, this survey found that these highly productive wetlands efficiently transform nutrients into a large pool of dissolved organic and particulate N and P. Hence, wetland lakes may behave widely as net sources of organic N and P to downstream waters and coastal marine systems.     

Complete periodical geological time table

Conclusion The proposal for a new complete classification of the Earth's evolution in accordance with periods of geotectonic cycles — depending on the external cosmic influence of the galactic year — has been elaborated as an additional application of a system model. Its basic idea is the principle of a hierarchical division and recurring cycles. For the time being, the significance of a periodical time table is a theoretical one. It allows a new view to be used when evaluating the last stages of the Earth's history during the Phanerozoic for which comparatively more geological information is available. However, a universal approach like the one described above can aid in directing further research on the older history of the Earth. Later on, theoretical knowledge could be applied to economic geology, above all if using a hierarchical classification of the phases of geotectonic cycles.