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1.
Martin Dunst 《Pure and Applied Geophysics》1977,115(3):459-471
Considering the blocking problem as a baroclinic instability problem in a dispersive wave system with diabatic heating effects, it is of great interest to investigate the role of wavegroup velocityv
gr in blocking processes, becausev
gr controls the energy transfer in the wave field. Using a Newtonian Cooling —type of forcing with a phase differencek to the main field and taking the linearized version of a two-level model, the phase speedc
r, the group velocityv
gr and the growth ratekc
i have been obtained as analytical functions of the mean zonal windU, the thermal windU
T, the coefficient of diabatic heating x, the phase differencek and the wavelengthL. Now the hypothesis is introduced, that a blocking should be expected, ifv
gr has a maximum value in the vicinity ofL
o, for whichc
r vanishes and thee-folding timet=1/kc
i (kc
i>0) is smaller than 6 days (see condition (20) in the text). One finds, that for special parameter combinations (U
T, U, ), where 15 m/secU
T25m/sec,U=10m/sec, 0.8·10–51.5·10–5 [sec–1], certain valuesL
o with an appropriate phase differencek exist, which satisfy the conditions mentioned above (for values see Table 2). TherebyL
o varies within the range 8500 km <L
o<11000 km corresponding to the preferred planetary blocking wavenumber 2 in middle latitudes 50°<<70° N. 相似文献
2.
Summary The distribution of radioactive(Th, U, K), major and selected trace(Rb, Sr, Ba, Y, Zr, V, Cr, Ni) elements of granulites from the Saxonian Granulite Complex was studied. Similarly to the South Bohemian granulites, the Saxonian granulites can be divided according to the contents of their major and trace elements into two main groups, groupA containing mostly acid and subacid granulites (K
2
O>2.5%, SiO
2
>68%), and groupB containing mostly intermediate and basic granulites (K
2
O<2.5%, SiO
2
<68%). Statistically significant differences between groupsA andB were found for all major oxides and several trace elements(Rb, V, Cr, Ni). The Saxonian granulites follow the same calc-alkaline trend as the South Bohemian, granulitesA being placed mostly in the rhyolite field and granulitesB mostly in the dacite, andesite and basalt fields of this trend. The investigated granulites are characterized by a considerable scatter ofTh andU contents accompanied by very variableTh/U ratios; theTh andU concentrations of granulitesA are substantially lower than is usual for rocks of corresponding acidity.
¶rt;a an¶rt;u a¶rt;uamu(Th, U, K) u ua ¶rt;u(Rb, Sr, Ba, Y, Zr, V, Cr, Ni) m aum n¶rt;a aaum na. naa, m u¶rt;aum n uu aam n aaum u ¶rt;u am aua, u u uu. aum n u uu ma a¶rt;um ¶rt; ¶rt;nn; nnA nua¶rt;ama a au¶rt; u au¶rt;aum (K 2 O>2,5%, Si O 2 >68%), nnB ¶rt;u u aum (K 2 O<2,5%, SiO 2 <68%). ¶rt; muunnau mm mamumuu m au ¶rt; a u u ¶rt; m ¶rt;u m(Rb, V, Cr, Ni). auaum n¶rt;¶rt;m um- m¶rt; a u -uaum;aumA a¶rt;ma a uum n, uaumB a a ¶rt;aum, a¶rt;um u aam n m m¶rt;a. ¶rt;aum — u unnA — aamum uu ¶rt;au da¶rt;uamu mTh uU.相似文献
3.
Alexander P. Anufriev Ivan Cupal Reviewer G. Siráň 《Studia Geophysica et Geodaetica》1987,31(1):37-42
Summary The behaviour of the poloidal and toroidal magnetic field at the core-mantle boundary is analysed in more detail, assuming that the conductive layer in the lowest mantle is thin. We can conclude that, in the case of the Z-model of the nearly symmetric hydromagnetic dynamo, the poloidal field may be considered potential everywhere in the mantle and that the azimuthal field depends on the geostrophic azimuthal velocity in the same manner as derived in[1] and[3].
aau ¶rt;-amu n¶rt;nuu m n¶rt; amuu aauum n¶rt;u nu¶rt;a u mu¶rt;a n. am ¶rt;, m Z-¶rt;u nmu umuu¶rt;aum ¶rt;ua aum nu¶rt;a n umam nmua ¶rt; amuu a n¶rt;u . ¶rt;m¶rt;am na [1] u [3] auum auma aum n m auma mu.相似文献
4.
Summary A non-linear model of trochoidal waves is presented which represents a geometrical and kinematical generalization of Gerstner's waves and of the results of[2–4].
¶rt;aam ¶rt; mu¶rt;a , ma m u ma u am[2–4] mu umuu u uamu mm ¶rt;u.相似文献
5.
Summary The relation of short period PKP1 and PKP2 amplitudes from deep earthquakes in the Tonga region observed at a seismological station in Central Europe, is compared with the theoretical relations computed for different source radiation parameters and depths. The Preliminary Earth Model was used in the computations. Qualitatively good agreement of observed and calculated values was found for the radiation pattern corresponding to the likely geometry of the Tonga subduction zone. The influence of the variation of some source and model parameters on the calculated PKP1 and PKP2 relation is discussed.
¶rt;a au mu anum¶rt; mnu¶rt; PKP1 u PKP2 mu mu a, anua ¶rt; u mau ma n, mmmuu mmuuu uuau, aumau ¶rt; a naam ua umua uu aa. ama unaa ¶rt; PREM. a¶rt; u auma uu ¶rt;am am au ¶rt; a uu, mmm mmuu ¶rt;uu a a. ¶rt;am uu auau naam umu u ¶rt;u a uu am mu anum¶rt; PKP1 u PKP2.相似文献
6.
Summary The accuracy of wave field extrapolation is studied with respect to the discretization of field data and integral extrapolator. Assuming a far-field approximation of the Rayleigh-Sommerfeld solution for a two-dimensional scalar wave equation, the minimum and the maximum transmitted frequency are expressed as functions of the sampling intervals t, x, and the half-width x0 and angle a of the migration aperture. The theoretical limitation of the transmitted frequency band is tested on numerical examples.
aamuam mm manuu auumu m ¶rt;umuauu n u uma manu nama. ¶rt; u uma u -¶rt;a ¶rt; ¶rt; a au, ¶rt; nuuuu ¶rt;a n mu ¶rt; uua u aua n¶rt;aa amm a uu m a -nmam ¶rt;umuauu t u , nuu 0 u a a uau anm. mu n¶rt;u amm ¶rt;uanaa mmua a u nua.相似文献
7.
Summary We search for the effects of the interplanetary magnetic field (IMF) sector boundary crossing (SBC) in upper stratospheric ozone. The SBUV data (Nimbus-7) at the 10, 3 and 1 hPa levels are analysed for latitudes 45° N and 55° N for winters of the period December 1979 to December 1982. An effect of the IMF SBC wos only found at the 10 hPa level. These first results concerning the IMF SBC effect in upper stratospheric ozone are rather preliminary.
¶rt;m uu nu mau () nam aum n () a mam. SBUV ¶rt;a (u-7) a nm ¶rt;au 10, 3 u 1a aauum ¶rt; um 45° u 55° . . ua nu¶rt;a ¶rt;a 1979 – ¶rt;a 1982. m uu a¶rt; m a 10a. mu n mam n uuu a mam m n¶rt;aumu.相似文献
8.
Summary The ionospheric effects of the interplanetary magnetic field (IMF) sector boundary crossings are studied for the winters of 1963–69. They are considerably stronger for proton than for non-proton sector boundaries. There are two different types of effects. The geomagnetic type is a disturbance, observed in geomagnetic activity, the night-time ionosphere and the day-time F2 region near the geomagnetic equator. The effect in the ionosphere is interpreted in terms of the IMF sector boundary crossing related changes in geomagnetic activity. The tropospheric type is aquietening, observed in tropospheric vorticity and in the day-time mid-and low-latitude ionosphere (except the geomagnetic equator region). The mechanism of this effect remains unexplained.
¶rt;m u m nu mau nam aum n () ¶rt; u 1963–69. u m u ¶rt; nm ¶rt; a mau. mm ¶rt;a m¶rt; muna m. aum m u, a¶rt;a aum amumu, u u ¶rt; F2 amu uuaum ama. mu u m ¶rt;mu uu aum amumu, m a nu mau . n mun m nu, a¶rt; aumu mn u ¶rt; ¶rt;- u uum u (a uu amuaum ama). au m ma um.相似文献
9.
Karel Diviš Vladimír Tobyáš Bohumil Chán Reviewer Z. Šimon 《Studia Geophysica et Geodaetica》1989,33(2):206-209
Summary A model, explaining the effect of air pressure changes in the space of the measuring system on the fine dial counter constant of the Worden and similar gravity meters, is presented. It is based on the changes of the bellows volume with compensating the gravity changes. It is shown that the resetting the gravity meter in the whole range has practically no influence on the fine dial counter constant.
u¶rt;a ¶rt;, na m uu ¶rt;au ¶rt;a nmam uum um a nm a umaauma ¶rt; u nuaum. ¶rt; aa a uu a ua umu uma nu nauu uu u mmu. aa, m nma ¶rt;uanaa um namuu um a uu nm a uma.相似文献
10.
Summary Based on model considerations it is shown that, under certain assumptions, upper cyclogenesis may be expected in the region of the auroral oval as a result of heat released at the time energetic particles of extraterrestrial origin penetrate into the lower stratosphere or even troposphere.
a auu ¶rt; a¶rt;u naa, m nu m n¶rt;nu u¶rt;am u amu aa aa mam ¶rt;u mna nuu muu amu nu¶rt;u u mam uu mn.相似文献
11.
Summary The effect of the IMF sector boundary crossing (IMF SBC) in the vorticity area index (VAI) — the well-known dip in the VAI after IMF SBC — is found to be independent of the IMF SBC effect in the cosmic ray flux. This finding refutes a recent suggestion by Lundstedt [1] that the IMF SBC effect in VAI is caused by a decrease in cosmic ray flux, but supports the concept of the IMF SBC effects in the ionosphere and atmosphere developed by Latovika [2–4]. Cosmic rays seem to affect the troposphere in another way.
¶rt;mu nu mau nam aum n ( ) a u¶rt; na¶rt;u aumu () — um uu n — a¶rt; auu m ma nm uu . mm mam nam ¶rt;a n¶rt;u ¶rt;m¶rt;a [1], m m a nuu nma uu , n¶rt;¶rt;uam nu m u u am, aum amu [2–4]. am m uu u m um a mn ¶rt;u a.相似文献
12.
Summary The optimization of the method of determining the addition constant of an EDM is discussed. The advantages of the optimization procedure from the point of view of efficiency and improvement of accuracy are reported.
nuuu ¶rt; n¶rt;u a¶rt;¶rt;uu n ¶rt;. u nu n u uu u nu u.相似文献
13.
Summary By using a general model of optimum elimination of systematic effects[5], the procedure has been developed for the optimum processing of gravimetric observations affected by the drift in a one-stage net, and statistically justified characteristics of the accuracy of the points of this net have been determined.
u uuu u ¶rt;u nmua uuauu um amuu uu [5] aamaa m¶rt;ua nmua amuaumuu uu ¶rt; aa ¶rt;-man mu; nu¶rt; mamumuu aamumuu mmu m¶rt; m m mu.相似文献
14.
u uuuuaumau uu u m, ¶rt;u a mumau nmu a u nmu mau u nmmu. au n¶rt; nuau ¶rt;mam u u m. nua m¶rt; m u m¶rt;a aau (1960) ¶rt; uu . 相似文献
15.
Normal density earth models 总被引:1,自引:0,他引:1
Summary Models of the Earth's density, close to thePREM model, have been derived, they reproduce the external normal gravitational field of the Earth and its dynamic flattening, and are referred to as normal density models. The Earth's surface is approximated by an ellipsoid of the order of the flattening, or of its square. Of the group of normal models sgtisfying the solution of the inverse problem, the normal density modelHME2 is recommended. The spherically symmetric density modelPREM, which was corrected in the course of solving the inverse problem, thus creating the modifiedPREM-E2 model, was used as the a priori information.
¶rt; ¶rt;u an¶rt;u nmmu uu ¶rt;uPREM (m. a. a ¶rt;u nmmu), aumau n m u¶rt;mu na¶rt;am auaumau n u. m u annuum am unu¶rt; au. uau amu a ¶rt; mam H==0.003 273 994. ma ¶rt; a ¶rt; ¶rt;m ¶rt;HME2. am anu u a ¶rt; nmmu a unaa ¶rt; a¶rt;ua umua ¶rt;PREM. ¶rt;aam ¶rt;uuau m ¶rt;u n¶rt; aauPREM-E2.相似文献
16.
Vlastislav Červený Jaromír Janský Reviewer I. Pšenčík 《Studia Geophysica et Geodaetica》1985,29(1):49-67
Summary A procedure of fast computation of body-wave ray synthetic seismograms in vertically inhomogeneous media is suggested. The procedure uses a special approximation of the velocitydepth distribution which guarantees continuity of the first and second derivatives of velocity and does not generate false low-velocity layers (oscillations in the velocity-depth function). The ZESY82 program package, which is based on the suggested procedure, is described. The point source with an arbitrary radiation pattern may be situated at any points of the model, the receivers are situated regularly or irregularly along any profile on the Earth's surface, containing the epicentre. Numerical examples of the synthetic record sections for a model of the Earth's crust and the uppermost mantle are given.
¶rt;aam m¶rt; m ama ummuu a mua ¶rt;¶rt; ¶rt;, u¶rt; u nua annuauu m aa, ma nuam nm mu u n u m nu¶rt; u nu¶rt;um aau um nu mu. am nua aumn na ZESY82, a a m m¶rt;. umu aamumu uu an m ¶rt;u; nuuu ¶rt; m an¶rt; ¶rt; nu, ¶rt;a num. u¶rt; nu ummuu a ¶rt; ¶rt; ¶rt;u u amuu.相似文献
17.
Summary The tidal deformations of a viscoelastic body are studied using the simple Kelvin-Voigt model. Expressions for the phase lag and amplitude change of the displacement vector are derived. The energy dissipation rate is calculated for the main disturbing bodies and for diurnal and semidiurnal tidal waves.
am nuu ¶rt;auu n ma ua-ma. ¶rt; au ¶rt; ana¶rt;au a u uu anum¶rt; ma u. aumaa m ¶rt;uunauu uu ¶rt; u a a m u nm .相似文献
18.
nua u mam n ma aa ¶rt;mn ¶rt;u aa, ma a n¶rt;a [1]. mma m ¶rt;u aa a ¶rt;auu nauMi (uuuu n) uMa (¶rt;uauu anm), m amm u nu [2–5]. u¶rt;m mam u nu ¶rt;u ¶rt; u¶rt; mu ¶rt; u a ¶rt; ¶rt;a. mu a aa, n¶rt;ua m a aa, nua a¶rt; u u i uu a a¶rt; zi nu nu aa ¶rt; ¶rt;a, m ¶rt;um mua m, a¶rt;u ¶rt; a, ¶rt;m, mnam, anu ¶rt; naa, nm a an u nu. a ¶rt;mn ¶rt;u m n a nu u ¶rt;mn ¶rt;u, ma a ma n¶rt;a [1]. 相似文献
19.
Jaromír Janský Jan Zedník Vít Kárník Reviewer J. Vaněk 《Studia Geophysica et Geodaetica》1988,32(3):264-271
Summary The theoretical medium period PV-magnitude calibrating curves were computed for the Earth model PREM and a wide range of focal depths. The calculated set of curves reflects the distribution of model parameters, the influence of source radiation was not taken into account. The widely used Gutenberg's empirical calibrating curves were compared with the theoretical ones. Pronounced deviations in the shape and differences in the level of isolines were found. Thus, if model PREM is considered to be representative of the Earth's structure, the empirical calibrating curves (D, h) for magnitude determination currently used in seismological practice, have to be verified.
auma mmuu au u u ¶rt; n¶rt;u aum¶rt; - n ¶rt;nu¶rt; annaam ¶rt; ¶rt;u u RE u ¶rt;uanau aa. uu maam an¶rt;u naam ¶rt;u ma uu u umua. u nu nuuu au u ma u a mmuuu uu. u a¶rt; mu auu n u u. au a, u num ¶rt; RE n¶rt;maum ¶rt; mu u, m ¶rt;u num nuuu au u (D, h) ¶rt; n¶rt;u aum¶rt;, m am unm u namu.相似文献
20.
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