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481.
M. Široká C. Fischer V. Cassé R. Brožková J.-F. Geleyn 《Meteorology and Atmospheric Physics》2003,82(1-4):227-244
Summary ?The paper deals with an alternative formulation of the so-called NMC (National Meteorological Center, now National Centers
for Environmental Prediction) statistics to compute the background error covariance matrix to be used in a mesoscale variational
analysis. While the standard method uses differences of forecasts valid for the same time, but starting from different analysis
times, the new formulation required the recomputation of the short-term forecast with the initial and lateral boundary data
that come from the long-term run. In the frame of a limited-area model, this approach forces the error variances at large
scales to decrease drastically, because those scales are controlled by the (constant data) lateral boundary coupling. As a
result, the background cost function acts more scale selectively, with an emphasis on medium scales. The analysis increments
obtained from the 3D-VAR system show that the analysis increments are sharper and more concentrated with the new formulation,
both in single observation and in full observation experiments. This work is part of a wider project for building a variational
assimilation system inside the ALADIN model. The complete system should concentrate on mesoscale features and it should not
reanalyse those scales that were already treated by the global model (ARPEGE). Some difficulties and perspectives are drawn
in the concluding discussion.
Received February 12, 2001; revised July 24, 2001 相似文献
482.
Vladimír Tobyáš Karel Diviš Reviewer O. Novotný Reviewer Z. Šimon 《Studia Geophysica et Geodaetica》1979,23(2):122-130
Summary Using the least-squares method the constants of both gravity meters — seismometers — were derived from the amplitude responses, observed under vertical motion on a vibrating table in the 0.3–30 s range. The values of the seismogram amplitudes, above which seismic waves cause an observable displacement of the gravity meter reading beam, were determined for the SKD and Press-Ewing station seismographs. 相似文献
483.
Influence of atmospheric pressure variations on measurements made with Sharpe and Worden gravimeters
Ladislav Gargalovič Ludmila Kubáčková Ivana Jakubcová Reviewer Z. Šimon 《Studia Geophysica et Geodaetica》1978,22(1):93-98
Summary The paper deals with the influence of the atmospheric pressure variations on Sharpe gravimeters CG 2 No. 226 and 280 and on the Worden gravimeter No. 978, equipped with a thermostat.Dedicated to RNDr. Jan Pícha, CSc., on his 60th Birthday 相似文献
484.
The concept of seismicity of fast tensile fracturing is introduced and supported by the results of shear and of combined shear and tensile displacements along a loaded stress concentrator. The seismicity of tensile fracturing is demonstrated by means of acoustic (elastic) signals obtained during tensile fracturing in physical models under load; the basic physical relations between the parameters characterizing the loaded medium, load conditions, shear and tensile displacements, and release of acoustic energy are presented. For determining the tensile-source component in earthquakes a procedure based on the construction of radiation patterns is suggested and submitted for discussion. The criteria for selecting earthquakes with possible shear-tensile source mechanisms are listed and discussed. The existence of such a combined seismic source is sought in two shallow earthquakes which occurred in southern Iran in March 1977. In general, the paper should be regarded as a proposal to utilize the radiation characteristics of a seismic source—with all their insufficiencies—as a quick and simple tool for seeking combined shear and tensile mechanisms of seismic energy release. 相似文献
485.
Summary The effect of an additional homogeneous magnetic field with an intensity of 0–4.5 Oe on the Worden quartz gravity meter No. 961 and on Sharpe quartz gravity meters Nos 173 and 174 was tested. Whereas no effect was observed with the Worden gravity meter, the magnetic field had a measurable effect on both the Sharpe gravity meters. The largest deviation of the reading beam is caused by the horizontal component of the magnetic field which acts in the plane of oscillation of the gravity-meter arm. The Sharpe gravity meter No. 173 is considerably sensitive; a field of 0.2 Oe intensity, corresponding to the magnitude of the horizontal component of the geomagnetic field in mid-latitudes, causes an error in the measurement of gravity of as much as 0.08 mGal. With a view to the different behaviours of the individual quartz gravity meters of the same type in a magnetic field, it should prove expedient to carry out check measurements with all gravity meters and, with regard to the sensitivity of the gravity meter to the magnetic field and the required accuracy of the gravity determination, take into account this perturbing factor in field measurements, as well as laboratory tests of gravity meters. 相似文献
486.
¶rt;aam mum nmu n u mmu u m , m ¶rt;um m nm am nuu n. ¶rt;uu u m ¶rt;m nam m. . ¶rt;uu¶rt;, m ¶rt;um nm ¶rt;au m nuu nmuaa u a. u uuu m mu¶rt;a n ma ¶rt;u ¶rt;um nnau a m uu.
Paper presented at the IUGG XVII Plenary Meeting, Canberra, Dec. 1979. 相似文献
Paper presented at the IUGG XVII Plenary Meeting, Canberra, Dec. 1979. 相似文献
487.
m¶rt; ¶rt;ua nuu aaua u¶rt;m nuu ¶rt; a ¶rt;u nuu uu u u mmu, ¶rt;au mmuu au nuu uu, a uu u u . aam, m um m n¶rt; mmu m¶rt;a, a nu a ¶rt;uana m u nm . u uam u ¶rt; 2- mnu, m m ¶rt;mam. ua am u uam, n¶rt; , m , u m nuu u ó ¶rt; a¶rt;amu uu ¶rt;uu a. ¶rt;mu umauu ¶rt;a ¶rt; auau m uum u nu¶rt;u aama. 相似文献
488.
Summary Since the beginning of the I.G.Y. collections of precipitation for chemical analysis have been made at 22 sample stations distributed all over the territory of Czechoslovakia at different heights above sea level. Analyses are carried out in the laboratories of the Geophysical Institute, Department of Physics of the Air, Hradec Králové. This preliminary report deals with the results of analyses during which the content of chloride ions was determined independently by the polarographic and the microtitration technique, while the content of nitrate ions was established polarographically. Distribution of concentrations of chlorides over the territory of Czechoslovakia represents a roughly homogeneous distribution of concentrations varying in a half year average from 0.6 mg/l to 6.6 mg/l. Generally higher concentrations can befound in mountain stations in the neighbourhood of industrial centres. In the winter months the values are higher than in the summer months in most of the stations. This is commonly due to a higher content of chlorides in solid precipitation as can be seen from the enclosed chart. A correlation between the concentration of chlorides and the intensity of the precipitation is not always clearly visible. Distribution of nitrates does not correspond with the character of the iso-lines of chlorides. Average concentrations range from 0.2 mg/l to 1.5 mg/l. The highest values were not found in the precipitations collected in the mountain stations. This would suggest a different distribution of chemical components of chlorides and nitrates in the lower levels of the troposphere which is clearly illustrated by the established concentrations in the region of High Tatra where the precipitations are collected in two neighbouring stations the height difference of which reaches nearly 2,000 m. 相似文献
489.
J. Šajgalik 《GeoJournal》1991,24(2):165-174
The Slovak Carpathians in Pleistocene presented a very articulate territory, so that loesses, as well as loess-like deposits could occur here with various lithofacial types.Based on a complex evaluation of a great number of loess samples of the Danubian lowland and their analysis by methods of mathematical statistics, it was possible to create a realistic model of the base soil. For the statistical processing we picked 4 selective sets of the Danubian lowland hilly country, where each set can be considered as a homogeneous engineering geological type.By comparing the loess properties of the Danubian lowland with the loesses of other European countries (mainly USSR), it can be stated that the studied loesses are not so dangerous from the sagging standpoint. The increase of the oedometric modulus with the depth was shown. Similar relationships were derived also for the parametres of shear strength.The regional characteristics of the loess mechanical properties will serve well in the initial phases of investigation, planning and designing, but also in more exact geoo technical calculations. 相似文献
490.
Ondřej Čadek Reviewer M. Pick Reviewer J. Šílený 《Studia Geophysica et Geodaetica》1989,33(2):177-197
Summary The technique of spherical tensors is applied to the problem of stress in the mantle. An efficient method for stress computation is developed for the Newtonian mantle with spherical boundaries assuming that the density and gravitational potential in the form of harmonic expansions are known. The ways of including more complicated rheological models as well as the non-spherical shape of boundaries are outlined.
¶rt; m¶rt; ama anu amuu, m a a nuuu annaama uuauu m. ¶rt;naam, m au nmmu uaumau nmuaa n uu u um u m amu n¶rt;mam u¶rt;m uuuauau. ¶rt; mu u m¶rt;a a a uu ¶rt; u u au.相似文献