A possible relation between geomagnetic activity and winter air surface temperatures in Prague     

Josef Pýcha  Pavel Hejda  Josef Bochníček 《Studia Geophysica et Geodaetica》1992,36(4):329-337

Summary A possible relation between the 10-day geomagnetic activity, solar activity and temperatures as measured at the meteorological station Prague - Klementinum in 1932–1975 was sought. It was found that: 1) Kp correlates with the surface temperature in Prague substantially better than Wolf's number R. 2) The correlation between Kp and the surface air temperature is not very close, but is significant at the level p=0.9! 3) If the QBO phase is taken into account, the correlations for the January and February decades of the years 1956–1975 improve as in [27] (van Loon, Labitzke).  相似文献   

The amplitude curves of reflected harmonic waves around the critical point     

Vlastislav Červený 《Studia Geophysica et Geodaetica》1961,5(4):319-351

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Structure of the inner corona derived from observations of the eclipse of 16 February 1980     

O. G. Badalyan  M. A. Livshits  J. Sýkora 《Solar physics》1984,93(1):143-153

The volume emission measure EM(V) of the arch systems of the inner corona, not immediately associated with developed active regions, has been determined by analyzing the pictures of the green corona. It was found that the EM(V)-values of these systems are substantially lower than those obtained from X-ray data for the active regions, and this fact should be taken into account in interpreting extra-atmospheric observations. The combined investigation of data on the radiation of the corona in the green line and in the continuum enables one to determine the total extension of the radiating matter, (0.5–1) × 10¹⁰ cm, as well as the density in the separate arches, 1.5 × 10⁹ cm^-3. It is assumed that matter exists between the arches with a density of 10⁸ cm^-3.  相似文献   

Sunspot activity according to Greenwich observations     

M. Kopecký 《Solar physics》1984,93(1):181-187

This article presents a survey of studies incorporating methods of evaluation of Greenwich observations. It also describes some extreme sunspot groups (i.e., groups with a very large area, a very long life, and/or in very high heliographic latitudes); data on the total areas of the largest sunspots are given, and a survey of the parameters concerning individual 11-year cycles, resulting from Greenwich Photoheliographic Results, is presented.  相似文献   

The12C/13C isotope ratio in comets,stars and interstellar matter     

Vladimír Vanýsek  Jürgen Rahe 《Earth, Moon, and Planets》1978,18(4):441-446

The¹²C/¹³C isotope ratio in the interstellar medium and in stellar atmospheres is discussed and compared to the value found in the solar system and especially in comets. The cometary value (100) tends to be slightly above the terrestrial value and is definitively higher than that for interstellar molecular clouds (about 30 to 50).This result implies that comets are not of interstellar origin; that the original isotopic abundances of the primitive solar nebula has been preserved in the cometary material; and that due to an enrichment of the interstellar medium in¹³C, the¹²C/¹³C isotope ratio has decreased by a factor of about 2.5 since the formation of the solar system (i.e., during the past 4.5×10⁹ years) — a result which is roughly in agreement with present theories of the chemical evolution of our Galaxy. The relatively high cometary carbon isotope ratio (as compared to the terrestrial value) indicates that some correction should be applied to the semi-empirical models describing the¹³C enrichment in the Galaxy.Paper dedicated to Professor Hannes Alfvén, on the occasion of his 70th birthday, 30 May, 1978.  相似文献   

Disturbance of ionosphere during American high-altitude nuclear explosion of 9. 7. 1962 indicated by atmospherics in central Europe     

Ladislav Křivský 《Studia Geophysica et Geodaetica》1963,7(3):296-298

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On Stable Chaos in the Asteroid Belt     

Miloš Šidlichovský 《Celestial Mechanics and Dynamical Astronomy》1999,73(1-4):77-86

The twenty most chaotic objects found among first hundred of numbered asteroids are studied. Lyapunov time calculated with and without inner planets indicates that for eleven of those asteroids the strongest chaotic effect results from the resonances with Mars. The filtered semimajor axis displays an abrupt variation only when a close approach to Mars takes place. The study of the behaviour of the critical argument for candidate resonances can reveal which is responsible for the semimajor axis variation. We have determined these resonances for the asteroids in question. For the asteroids chaotic even without the inner planets we have determined the most important resonances with Jupiter, or three-body resonances. This revised version was published online in July 2006 with corrections to the Cover Date.  相似文献   

Possible geomagnetic activity effects on weather     

J. Bochníček  P. Hejda  V. Bucha  J. Pýcha 《Annales Geophysicae》1999,17(7):925-932

Tropospheric temperature and pressure fields on the Northern Hemisphere in the winter periods 1952–1996 were investigated. Composite maps of those fields, created for the high and low geomagnetic activity and individual quasi-biennial oscillation (QBO), phases show clear differences not only between different levels of geomagnetic activity, but also between the two phases of QBO. Special attention was given to the behaviour of the lower troposphere in January and February 1982.  相似文献   

The formation of fan-deltas in mountain lakes: Findings from Zelené Kežmarské Lake (Slovakia)     

Marcin Słowik  Marta Prekopová  Vladimír Budinský 《地球表面变化过程与地形》2024,49(2):933-948

Fan-deltas are formed in mountain lakes, contributing to changes in shorelines' shapes and filling lake basins with sediments. Factors that condition sediment delivery to the lakes and the formation of fan-deltas are not fully understood. This study aims to identify processes forming fan-deltas in mountain lakes based on the sedimentary architecture of a fan-delta filling Zelené Kežmarské Lake (Slovakia). Our study is based on ground-penetrating radar and seismic refraction surveys conducted over the lake and debris-flow fans in its vicinity, and grain-size analyses of the surface deposits. The internal structure of the fan-delta comprises foreset deposits representing the fan-delta lobes. Mouth bars were identified in the near-shore zone. The fan-delta is built of sands and silty sands whereas an alluvial debris-flow dominated fan west of the lake contains gravels. A general trend of downslope fining of the fan surface sediments, disturbed by zones of coarse gravels, was identified in the surficial sediments forming the fan. The fan-delta was formed by depositional events in humid periods, alternating with dry periods featured with a small or no deposition. The lake-level steadily rose in the humid periods and remained stable in dry periods. The contrast between the coarse sediments forming the alluvial debris-flow dominated fan, and sands forming the fan-delta was caused by a selective deposition. Coarse gravels in the fan were mobilized in humid periods but did not reach the lake-shore. The reason was a basement rock ridge situated parallel to the lake shore. Sands were delivered to the fan-delta in humid periods owing to frequent high-energy flows. A deposition of silts took place in dry periods. The studied fan-delta might preserve the sedimentary record of three humid periods from the last 200 years. However, further studies are needed to establish the timing of the fan-delta formation.  相似文献   

Constructing Site-Specific Climate Change Scenarios on a Monthly Scale Using Statistical Downscaling   总被引：1，自引：1，他引：0  

R. Huth  J. Kyselý 《Theoretical and Applied Climatology》2000,66(1-2):13-27

Summary Monthly mean temperature and monthly precipitation totals in two small catchments in the Czech Republic are estimated from large-scale 500 hPa height and 1000/500 hPa thickness fields using statistical downscaling. The method used is multiple linear regression. Whereas precipitation can be determined from large-scale fields with some confidence in only a few months of the year, temperature can be determined successfully. Principal components calculated separately from the height and thickness anomalies are identified as the best predictor set. The method is most accurate if the regression is performed using seasons based on three months. The test on an independent sample, consisting of warm seasons, confirms that the method successfully reproduces the difference in mean temperature between two climatic states, which indicates that this downscaling method is applicable for constructing scenarios of a future climate change. The ECHAM3 GCM is used for scenario construction. The GCM is shown to simulate surface temperature and precipitation with low accuracy, whereas the large-scale atmospheric fields are reproduced well; this justifies the downscaling approach. The observed regression equations are applied to 2xCO₂ GCM output so that the model’s bias is eleminated. This procedure is then discussed and finally, temperature scenarios for the 2xCO₂ climate are constructed for the two catchments. Received December 3, 1998 Revised December 4, 1999  相似文献