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1.
Miloslav Kopecký 《Studia Geophysica et Geodaetica》1990,34(1):37-45
Summary Sunspot indices characterizing the 11-year cycle as a whole were determined on the basis of Wolf's sunspot numbers and their total area as well as on the basis of the primary physically indices of the spot-generating activity of the Sun.Their interrelationship is shown and their relationship to the indices of geomagnetic activity aa and Ci is examined. It is shown that under high solar activity a certain saturation of the Earth's magnetosphere occurs and that the variations of geomagnetic activity correlate with the variations of the global sunspot indices (Wolf number and total area) but correlate but slightly with the primary physically sunspot indices.
u u n¶rt;;u nm u uuu nu u¶rt;; nmaoam ¶rt;;mmu q, n¶rt;; u¶rt;;u nm, aamuu -mu u . aaa u aua u u u mu u¶rt;;a ¶rt;;a¶rt;;um amumu aa u i. aa, m nu amumu mynam am aum u m auauu ¶rt;;a¶rt;;umo amumu um auauau ¶rt;; u¶rt;; nm (u a, aa na¶rt;), a um uuu nuu u¶rt;u nm.相似文献
2.
The Gaussian beam method is applied to vertical seismic profiling in 2-D and 3-D models. A simple approach to the computation of Gaussian beam seismograms in the vicinity of structural interfaces is proposed. The effects of (a) the radiation pattern of a point source, (b) non-causal attenuation, (c) transverse inhomogeneities in synthetic seismograms are studied on numerical examples. 相似文献
3.
We have developed an algorithm that allows crosshole georadar amplitude data contaminated with systematic errors to be tomographically inverted. The effects of the errors, which may due to variable antenna-borehole coupling, the groundwater table, and 3-D heterogeneities in the vicinity of one or more boreholes, are included in a series of transmitter and receiver amplitude-correction factors. Tests with synthetic georadar sections demonstrate that the new approach is capable of producing reliable attenuation information, even when large systematic errors are present in the amplitude data. Standard inversions of crosshole georadar data acquired within a highly complex alpine rock glacier yield distorted tomograms. In contrast the new approach results in geologically useful images. 相似文献
4.
5.
Summary Based on the relation between the relative sunspot number R, the number of sunspot groups f
0
generated per unit time on the Sun as a whole and their average lifetime T
0
, and on the extrapolation of time behaviour of f
0
and T
0
, it is proved that abnormally high solar activity may be expected in the first half of the 21st century. At this time, the maximum annual relative sunspot numbers RM of the 11-year cycles should reach values of about 300 units. This abnormally high solar activity in the next century can be understood as the antipole of the Maunderean minimum. This forecast is used to discuss some of the possible consequences of this abnormally high solar activity for the processes on the Earth: changes of climate (heat waves and draughts in Central Europe), in the higher layers of the Earth's atmosphere (anomalous propagation of radio waves, increased effect of the density of the upper atmosphere on the orbits of man-made satellites), in seismicity (increased seismic activity in Europe and Southeast Asia), for technical devices (induced electric currents), in the biosphere. etc.
a mu ¶rt; uau a R nm, unn nm f 0 uu ¶rt;uu u a ë u u ¶rt; n¶rt;ummu uu 0 , u a manuu ¶rt;a f 0 u 0 , naa, m n nu ¶rt; 21 a u¶rt;am uum amum. aua¶rt;u ua a R m¶rt; 11-mu ua m u ¶rt;muam au 300 ¶rt;uu. m uum amum ¶rt; nuam a amun¶rt; a¶rt; uua. a m na ¶rt;am m n¶rt;mu m uum amumu a n nmau a : a uu uama (aa u a n¶rt;a ¶rt; n), a u u am u (aa anmau a¶rt;u, uu n nmmu u am a ¶rt;uu um m), a um (na ua amum n u -m uu), a muu mma (u¶rt;ua muu mu), a u u ma ¶rt;a.相似文献
6.
The asymptotic distribution of the coefficient of cross-association between two sequences of nominal data is investigated under the assumption of independent random sampling from a multinomial distribution slightly modified to suit geological applications. This modification is due to merging consecutive strata of the same rock type into one lithological unit, and can be described by a simple Markov chain. A distinction is made between the case in which the theoretical frequencies are known, and the situation where these have to be estimated from the observed data. 相似文献
7.
This paper is devoted to the testing experiment of a postprocessing tool aimed at the objective analysis of propagating gust fronts in a given convective environment. The tool is being developed to be applicable in the operational mode by utilizing NWP model outputs. The experiment was carried out on two summer convective cases which occurred in the Czech Republic. The cases were numerically simulated by the limited area NWP model LM COSMO with the horizontal resolution of 2.8 km. They represent different types of convective systems, both accompanied by objectively identifiable gust fronts and causing heavy precipitation. The event from July 2000 was characterised by the development of isolated thunderstorms. The other event from July 1998 was a long-lasting and organised convective system — a squall line. The hypothesis was that the developed postprocessing tool is capable to evaluate the role which downdraft outflows played in the decay and initiation of convective cells by interaction with convective environment and thus in prolongation of convection lifetime.The procedures of the Objective Analysis of Gust Fronts (OAGF) were applied to the thermodynamic outputs of the LM COSMO. The aim was to determine the position of gust fronts within the domain and to assess their speed of movement and the potential to initiate convection according to the properties of ambient vertical shear and stability as well as humidity conditions ahead of the respective downdraft outflows. In addition, the Radar Simulation Model (RSM) was employed to monitor the simulated convective systems in arbitrary PPI and RHI scans and to verify qualitatively the LM COSMO precipitation forecasts.The case studies has confirmed the applicability of the LM COSMO–OAGF chain and RSM, which may represent the potential for improving the operational nowcasting of hazardous convection phenomena. In both simulations, the objective gust fronts moved on into the vertical shear-favourable environment for triggering new convection. In addition to the dynamical organisation, there were also favourable stability and humidity conditions in the area of forced upward motions in the simulation of the event from July 2000. 相似文献
8.
9.
Matched-field tracking (MFT) algorithms have been successfully applied to both simulated and measured data to determine the most likely positions of a sound source that is localized ambiguously by a matched-field processing (MFP) system. They have been used to track sources moving linearly or on a circular path at constant speed and heading. The input to the trackers is a set of ambiguity surfaces, contiguous in time, generated by MFP. These algorithms assume that the track start and end times are known a priori; this restriction is removed in the piecewise MFT algorithm (PTA). The PTA was applied to narrow-band measured data collected during the PACIFIC SHELF 93 trial to successfully identify the significant source track segments 相似文献
10.
Zdeněk MikulÁšek Luboš Kohoutek Miloslav Zejda Ondřej Pejcha 《Astrophysics and Space Science》2005,296(1-4):465-468
We confirm the presence of regular UBV(RI)C light variations of the object in the center of the planetary nebula Sh 2-71, with an improved period of P = 68.132 ± 0.005 days. The shapes and amplitudes of light curves, in particular colours, are briefly discussed. 相似文献