Long-term variability of occurrence of precipitation forms in winter in Kraków, Poland   总被引：1，自引：0，他引：1  

Robert Twardosz  Ewa ?upikasza  Tadeusz Nied?wied?  Adam Walanus 《Climatic change》2012,113(3-4):623-638

The paper discusses long-term change in snowfall, rainfall and mixed precipitation viewed in conjunction with air temperature and North Atlantic Oscillation (NAO) in winter (December–February). In the study of contemporary climate change and its effect on the hydrological cycle it is useful to focus on winter precipitation forms. A 146-year secular observation series from Kraków, spanning the period 1863–2008, was used to extract data on the number of days with precipitation and on precipitation amount broken down by form. Statistically significant trends were found in total and mixed precipitation, but not in snowfall and rainfall. The climate warming effect has contributed to a material decrease in the snowfall to total winter precipitation ratio during the second half of the 20th c. The highest impact of air temperature was found in the wintertime variation in number of days with snowfall while the NAO had a significant influence on the frequency and amount of both rainfall and snowfall.  相似文献   

Light and motion in SDSS Stripe 82: the catalogues     

D. M. Bramich  S. Vidrih  L. Wyrzykowski  J. A. Munn  H. Lin  N. W. Evans  M. C. Smith  V. Belokurov  G. Gilmore  D. B. Zucker  P. C. Hewett  L. L. Watkins  D. C. Faria  M. Fellhauer  G. Miknaitis  D. Bizyaev  &#;. Ivezi&#;  D. P. Schneider  S. A. Snedden  E. Malanushenko  V. Malanushenko  K. Pan 《Monthly notices of the Royal Astronomical Society》2008,386(2):887-902

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Searching for the Parent of the Tunguska Cosmic Body     

Tadeusz Jan Jopek  Christiane Froeschlé  Robert Gonczi  Piotr A. Dybczyński 《Earth, Moon, and Planets》2008,102(1-4):53-58

We present the results of an extensive study of the Tunguska Cosmic Body (TCB) origin on dynamical grounds. To identify the TCB parent, or a plausible candidate, we applied the well-known concept of dynamical similarity whereby we have compared the geocentric and heliocentric dynamical parameters of a selected set of the Near Earth Objects (NEOs) and TCB particles. First, we made use the idea of Kresak by comparing geocentric coordinates of the TCB radiant with those of the NEOs. Second, we studied the long-term dynamical evolution of all NEOs and TCB particles searching for similarities between their heliocentric orbits. As a general result, we observed many more similar cases and a different pattern of the high orbital similarity among the TCB particles and the asteroid orbits than we did for comets.  相似文献   

ARTEMiS (Automated Robotic Terrestrial Exoplanet Microlensing Search): A possible expert‐system based cooperative effort to hunt for planets of Earth mass and below     

M. Dominik  K. Horne  A. Allan  N.J. Rattenbury  Y. Tsapras  C. Snodgrass  M.F. Bode  M.J. Burgdorf  S.N. Fraser  E. Kerins  C.J. Mottram  I.A. Steele  R.A. Street  P.J. Wheatley  &#x;. Wyrzykowski 《Astronomische Nachrichten》2008,329(3):248-251

The technique of gravitational microlensing is currently unique in its ability to provide a sample of terrestrial exoplanets around both Galactic disk and bulge stars, allowing to measure their abundance and determine their distribution with respect to mass and orbital separation. Thus, valuable information for testing models of planet formation and orbital migration is gathered, constituting an important piece in the puzzle for the existence of life forms throughout the Universe. In order to achieve these goals in reasonable time, a well‐coordinated effort involving a network of either 2m or 4×1m telescopes at each site is required. It could lead to the first detection of an Earth‐mass planet outside the Solar system, and even planets less massive than Earth could be discovered. From April 2008, ARTEMiS (Automated Robotic Terrestrial Exoplanet Microlensing Search) is planned to provide a platform for a three‐step strategy of survey, follow‐up, and anomaly monitoring. As an expert system embedded in eSTAR (e‐Science Telescopes for Astronomical Research), ARTEMiS will give advice for follow‐up based on a priority algorithm that selects targets to be observed in order to maximize the expected number of planet detections, and will also alert on deviations from ordinary microlensing light curves by means of the SIGNALMEN anomaly detector. While the use of the VOEvent (Virtual Observatory Event) protocol allows a direct interaction with the telescopes that are part of the HTN (Heterogeneous Telescope Networks) consortium, additional interfaces provide means of communication with all existing microlensing campaigns that rely on human observers. The success of discovering a planet by microlensing critically depends on the availability of a telescope in a suitable location at the right time, which can mean within 10 min. To encourage follow‐up observations, microlensing campaigns are therefore releasing photometric data in real time. On ongoing planetary anomalies, world‐wide efforts are being undertaken to make sure that sufficient data are obtained, since there is no second chance. Real‐time modelling offers the opportunity of live discovery of extra‐solar planets, thereby providing “Science live to your home”. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)  相似文献   

The influence of atmospheric circulation on the type of precipitation (Krak��w, southern Poland)     

Robert Twardosz  Tadeusz Nied?wied?  Ewa ?upikasza 《Theoretical and Applied Climatology》2011,104(1-2):233-250

The paper discusses the impact of atmospheric circulation on the occurrence of various types of precipitation. A 146-year-long precipitation record from Kraków spanning the period 1863?C2008 was used alongside a calendar prepared by Nied?wied? (1981, 2009) describing circulation types covering the period 1873?C2008 and air masses and atmospheric fronts covering the period 1951?C2008 in southern Poland. The influence of atmospheric circulation on precipitation was measured using the frequency, conditional probability and average daily totals of precipitation. Circulation types, air masses and atmospheric fronts exerted influences on precipitation as a result of the seasonal variations of the thermal and moisture properties of air masses. The impact is best expressed by circulation types as these combine the aspect of cyclonicity/anticyclonicity with that of the direction of air advection, the two elements which determine the physical properties of the air. On average, liquid precipitation prevailed in all circulation types, except the Ea type in which snowfall dominated over liquid precipitation. Depending on the season, one of the three types of circulation, Wa, Wc and Bc, were shown to coincide with the greatest amount of liquid and thunderstorm precipitation. There was no single dominant circulation type for mixed precipitation or snowfall. In summer, the circulation types Nc, NEc, Cc and Bc were the most favourable to liquid and thunderstorm precipitation in terms of both probability and totals. In winter, snowfall was the most favoured by the Ec type. Frontal precipitation was twice as likely to occur as air mass precipitation, with the exception of snowfall which was predominantly an air mass type of precipitation in terms of probability, but its greatest totals were recorded on atmospheric fronts.  相似文献   

New ultracool and halo white dwarf candidates in SDSS Stripe 82     

S. Vidrih  D. M. Bramich  P. C. Hewett  N. W. Evans  G. Gilmore  S. Hodgkin  M. Smith  L. Wyrzykowski  V. Belokurov  M. Fellhauer  M. J. Irwin  R. G. McMahon  D. Zucker  J. A. Munn  H. Lin  G. Miknaitis  H. C. Harris  R. H. Lupton  D. P. Schneider 《Monthly notices of the Royal Astronomical Society》2007,382(2):515-525

A     region along the celestial equator (Stripe 82) has been imaged repeatedly from 1998 to 2005 by the Sloan Digital Sky Survey (SDSS). A new catalogue of ∼4 million light-motion curves, together with over 200 derived statistical quantities, for objects in Stripe 82 brighter than   r ∼21.5  has been constructed by combining these data by Bramich et al. This catalogue is at present the deepest catalogue of its kind. Extracting ∼130 000 objects with highest signal-to-noise ratio proper motions, we build a reduced proper motion diagram to illustrate the scientific promise of the catalogue. In this diagram, disc and halo subdwarfs are well-separated from the cool white dwarf sequence. Our sample of 1049 cool white dwarf candidates includes at least eight and possibly 21 new ultracool H-rich white dwarfs  ( T _eff < 4000 K)  and one new ultracool He-rich white dwarf candidate identified from their SDSS optical and UKIDSS infrared photometry. At least 10 new halo white dwarfs are also identified from their kinematics.  相似文献   

Geological prognosis of potential zinc and lead resources for Triassic formations in the Silesian-Cracow region in southern Poland     

Tadeusz J. Smakowski 《Mathematical Geology》1992,24(6):693-703

Geological prognosis of zinc and lead potential resources for Triassic formations was carried out for the Olkusz district in the southeast part of Silesian-Cracow region. Known deposits, typical phenomena in surrounding rocks, and quantitative methods for metallic ores for the perspective region or formation were a basis for the models. Statistical analysis of zinc and lead distributions and their interpretation were used to distinguish between the populations of background, anomalies, and ore bodies. Estimated values of the thresholds in the Triassic formations, i.e., 0.5 (anomalies) and 1.1 (ore bodies) wt. % of Zn, and 0.3 and 0.7 wt. % of Pb, respectively, represent the natural limits of concentration for both metals. Similar values of the thresholds obtained by other authors for other districts indicate regional regularities of zinc and lead concentration in the Triassic formations in the whole Silesian-Cracow region. Using these threshold values, the perspective zones of metals concentration can be proposed in the poorly explored areas of this region. In known deposits, the natural limit of zinc used as a cut-off value increase the reserves by about 30–40%.  相似文献   

Measurements of coastal suspended sediment concentrations     

Sergiei M. Antsyferov  Tadeusz Basinski  Nikolai V. Pykhov 《Coastal Engineering》1983,7(2):145-166

Three of the methods available for measurement of suspended sediment concentration were chosen and tested in natural conditions. The equipment included sand traps, a radioisotopic probe and a long-action sampler (bathometer).The working conditions of the equipment were studied and the reliability of data obtained was analyzed. Sources of possible errors have been defined together with requirements for the techniques, and optimum technical parameters have been found. Averaging times, necessary with regard to the reliability of data, have also been determined for the measurements. Calibration and cross-calibration of the measuring devices was carried out. Technological requirements, advantages and areas of applicability are discussed for the techniques. Although they require some modifications, the techniques can already be used in measurements of concentration profiles. The data obtained, and partly shown in this paper, shed light on complex phenomena of sediment suspension.  相似文献   

Radon-222 in medicinal groundwaters of Szczawno Zdrój (Sudety Mountains, SW Poland)     

Tadeusz Andrzej Przylibski  Krystian Mroczkowski  Adam Zebrowski  Paweł Filbier 《Environmental Geology》2001,40(4-5):429-439

 Radon is a significant component of the groundwaters that discharge in the springs of Szczawno Zdrój and are recognized as medicinal. However, among the five exploited springs adjoining each other, it is only in Marta Spring that radon occurs in large concentrations (up to 325.6 Bq/dm³). Therefore, the authors have made an attempt to describe and clarify this fact. They found out from their own research and archival data that ²²²Rn dissolves in the waters of Marta Spring after acidulous waters of deep circulation have mixed with poorly mineralized shallow waters in their outflow zone. The genesis of the gas is determined by the content of its parent nuclide, ²²⁶Ra, in the sandstones in the vicinity of the intake. The volume of the rocks providing radon to the waters of this intake has been estimated at several hundred cubic metres. No seasonal fluctuations in radon concentration have been observed and ²²²Rn concentration changes do not seem to be influenced by changes in the concentration of other chemical components of the waters or by the discharge of the intake. The process of dissolving ²²²Rn in the medicinal groundwaters of Marta Spring is the last, the shortest, and the most local of the processes that form the chemical composition and the physical properties of these waters. Received: 7 January 2000 · Accepted: 12 August 2000  相似文献   

Simulated annealing ray tracing in complex three‐dimensional media     

Danilo R. Velis  Tadeusz J. Ulrych 《Geophysical Journal International》2001,145(2):447-459

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