Changes in the reflectivity of the midlatitude ionosphere with respect to the ULF (Pc1) signal

Summary The method of numerical modelling of ionospheric filtration of the Fourier components of a signal from the frequency range of Pc1 micropulsations is employed in the spectral analysis (frequency f, angle of incidence ) of the relative characteristic of the amplitude and energy reflectivity of the ionospheric layer with respect to ordinary Alfvén modes incident in the meridional plane. The results are presented for four different models characterizing the midlatitude day- and night-time ionosphere under low and high solar activity. The results indicate the specificity of filtration of ordinary Alfvén waves. It is proved that the lower region of the modelled ionosphere, as part of the midlatitude ionospheric wave guide (in particular the F2 layer), behaves like an Alfvén resonator in the given spectral range.

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m¶rt; u ¶rt;uau u umauu -mau uaa u amm ¶rt;uanaa unau 1 n¶rtum nma aau (amma f, a¶rt;u ) mum anum¶rt; u mu maamu u ¶rt; ¶rt; a, a¶rt;au a u u¶rt;ua nmu. mam n¶rt;aam ¶rt; m a ¶rt; ¶rt;um m ¶rt; u u nu u u nu amumu. aam nuum umauu a. naa, m ua am ¶rt;ua u (a am F2-u ¶rt;um ¶rt;a) ¶rt;m nma ¶rt;uana a am a.

     

Study of the velocity conditions in the earth's crust in the regions of the Bohemian massif and the carpathian system along international profiles VI and VII

u¶rt;m n uu ¶rt;u m n u ma n¶rt;aa, nu m¶rt;u u ¶rt;uau. n nuu uu ¶rt;u m n ¶rt;a¶rt; nu NoNo VI, VII. u au u n m a (x, H), ¶rt;auu an¶rt;u ¶rt;u m ¶rt; m¶rt; nu, u mua m nuu (H), aamuu an¶rt;u m a mua ¶rt;¶rt; uu ¶rt;uua u a. u a ¶rt;u m (x, H) amm ¶rt;uuu (u) a m¶rt; nu. m¶rt; u, auuu aau, om aamuam muau an¶rt;u ¶rt;u m, uu , n m u m nu aamuu a nmu, am ma a¶rt;am aa uu ¶rt;u m. aa u a¶rt;u n nu NoNo VI u VII u umuu ¶rt;a. mua m nu (H) num m ¶rt;u amu aua u anam um, ¶rt;a amu ¶rt;aua u ¶rt;- nma (nu No VII). ma ¶rt; ¶rt; aua, maa numa nm m u numa nm ma¶rt;um, a unaa nuu umnmauu a¶rt;uu ¶rt;uau amu aua.     

Consequences of transducer inductance for seismograph calibration

Summary The magnification achieved with the standard sine-wave method using seismometers with the calibration and signal coils tightly wound on the same coil former can be erroneous at high frequencies due to the mutual inductance between both coils. An attempt was made to eliminate this influence from the calibration data. The application of theoretical equations was tested with a short-period digital seismograph.

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ma¶rt;ama auau aa nu ¶rt;uu ¶rt;uu maauu m m m a u amma ua u a au u¶rt;mumu ¶rt; ua u auau am, u u a¶rt;m n¶rt;m umu. a ¶rt;aa nnma muam auau ¶rt;a. uu mmuu au u¶rt;a nu auauu mnu¶rt;u aa u anu.

     

Relation between the field of surface heat flow and the distribution ofP n -wave velocities for continents

Summary The dependence between P_n-wave velocities and the surface heat flow, temperature at the core-mantl boundary and thickness of the Earth's crust for continents (Europe, Asia, North America and Australia) was investigated statistically in connection with the problem of lateral inhomogeneities in the upper mantle. The relations obtained were compared with those determined under laboratory conditions. The conclusion is that temperature and pressure effects may provide additional explanations of the regional variations of P_n-wave velocities observed in most continents.

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auum ¶rt;auu mu n¶rt; a nmu uua(P_n ), nm mn nm, mnam a u m mum a u¶rt;aa u n uuuma ¶rt;¶rt;m mu P_n. nua ¶rt;a mama aam u¶rt;au nu m n¶rt; amuu u u ¶rt;au u mnam a¶rt;um mmmuu mamau n¶rt;aa am. am ¶rt;, m ua uu m P_n- ¶rt; amu muma n¶rt;m auu m¶rt;uauu u a nmu muua.

     

Energy regimes in the Earth's magnetosphere

Summary The dynamics of the main processes of energy accumulation and dissipation in the Earth's magnetosphere at various geomagnetic disturbance levels is examined. The results of the relevant calculations are tabulated. The relationships between the energy parameters of the solar wind and the Earth's magnetosphere are analyzed. Some conclusions concerning the field-aligned currents in polar caps, the Joule dissipation of energy and the energy injection into the ring current, the energy releases in the upper ionosphere, etc., are drawn.

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ama ¶rt;uaua n anu u ¶rt;uunauu uu aum u nu au aum mu. mam uu n¶rt;ma maua. auum au ¶rt; muuu aamumuau ma u aum u. u¶rt;m m au n¶rt; ma n an, uu ¶rt; ¶rt;uunauu, uu uuu m, uu, ¶rt; u, u m. ¶rt;.

     

On the non-tidal secular acceleration of the Earth's rotation

Summary The secular positive acceleration of the Earth's rotation has been computed on the basis of the observed secular decrease of the second zonal harmonic[5]. It corresponds to the observed secular deceleration of the Earth's rotation which should be greater because of oceanic tides.

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¶rt; u a¶rt;a u m aauu [5], u ¶rt;a num u au. m mmmu a¶rt;a u mu au u, m.. n¶rt; n m uu , ¶rt; m n auu nuua.

     

Deuteron whistlers in the outer ionosphere

Summary Upgoing and downgoing deuteron whistlers were found on VLF records made by Interkosmos 5, 14 and 19 satellites even at heights below 1000 km. To account for them, a slight admixture ofD ⁺ ions has been introduced into the ionospheric plasma model with the usual content of only three ion speciesH ⁺,He ⁺ andO ⁺. Relations derived for the calculation of characteristic frequencies in a five-component plasma (e,H ⁺,D ⁺,He ⁺,O ⁺) are given as well as the values of characteristic frequencies calculated on this basis. The observed features of upgoing and downgoing deuteron whistlers could be explained by the calculation results, and it is also possible to formulate some conclusions for the purposes of plasma diagnostics.

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mu um, anmau a ma u u, u a a nmua m 5, 14 u 19 a ma ¶rt;a 1000 . u u a ¶rt;a ¶rt; u na ¶rt;au uH ⁺,He ⁺,O ⁺ aa nuD ⁺ u. m mm ua nma ¶rt;a ¶rt; aamumuu amm ¶rt;a ¶rt;u na. uu aamumuu amm nuu um a¶rt;a mu ¶rt;mu um. a m ¶rt; unam aamumuu ¶rt;mu um ¶rt; u¶rt;au naam na.

     

Radioactive and trace element distribution in basaltic rocks of Lower Silesia

Summary The distribution of radioactive(Th, U, K) and selected trace(Rb, Sr, Ba, Y, Zr, V, Cr, Ni) elements in volcanic rocks from the Opole and Jawor regions of the Lower Silesia has been studied. The behaviour of these elements in the studied rocks indicates that the Lower Silesian volcanic rocks are characterized by less differentiated type than other volcanic rocks of the Bohemian Massif, the Opole rock types probably having a less differentiated character than the Jawor rock types.

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¶rt;a an¶rt;u a¶rt;uamu(Th, U, K) u m ¶rt;u(Rb, Sr, Ba, Y, Zr, V, Cr, Ni) m auu n¶rt;a am n u u uuu. a n mam n¶rt;num, m aum u uuu n¶rt;mam ¶rt; aamuu n¶rt; u ¶rt;uuau, aum u ana¶rt; uu. au a n¶rt;num, m auu n¶rt; amu n ¶rt;uuau ma ua n¶rt; u amu .

     

On the possibility of utilizing grid reports in a local model of short-range forecast of meteorological elements

Summary In the experiment described, we test the possibility of utilizing forecasts of the pressure field, contained in GRID reports, to solve the problem of horizontal boundary conditions of a local model of short-range forecast of meteorological elements. We prove that the assumption of a linear tendency of the prognostic variables in the boundary region yields good results, using the Perkey-Kreitzberg method[1], even if applied to period T=24 hrs. In the Perkey-Kreitzberg method the effect of the horizontal diffusion in the boundary region is suppressed[2]. However, considering the diffusive term apart from the procedure of the method mentioned proves detrimental to the forecast.

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nua num n m unau n n ¶rt;au, ¶rt;au ¶rt; ¶rt; u numaau u a ¶rt;u am na muu m. aam, m n¶rt;nu u m¶rt;uu nmuu n au amu nu unauu m¶rt;a u- [1] ¶rt;am u mam ¶rt;a nu nuuu nu¶rt; T=24 a. m¶rt; u- nu¶rt;um n¶rt;au uuuma ¶rt;uuu au amu[2]. ama ¶rt;u a n¶rt; nu¶rt; m¶rt;a nu¶rt;um, ¶rt;a, ¶rt;u n.

     

Meteorological interpretation of infrared pictures of the earth from space

Summary This paper considers a number of questions concerning the interpretation of infrared pictures of the earth taken from space. Long period mean statistical values of the contrasts in radiation temperature between the earth's surface and clouds for a number of points in the U.S.S.R. in different seasons have been calculated which makes it possible to conclude when and where clouds against the underlying surface can be detected as well as to formulate the requirements which the instruments mounted on a satellite are to satisfy. The blackness coefficients of clouds at different layers have been theoretically determined, the investigation of the problem of the spectral regions selection for satellite observations has been conducted. The worked out calculation scheme has been used in the solution of the problem of the possibility of satellite detection of such thermal non-homogeneities as sea currents and jet streams in the atmosphere. Examples of the synoptical analysis of the infrared pictures of the cloud cover obtained with the help of the NIMBUS-1 and COSMOS-122 satellites have been considered. , . , , , , . , . , , . , -1 -122.     

Numerical modelling of time-harmonic seismic wave fields in simple structures by the gaussian beam method. part I

m¶rt;au n unm ¶rt; u ¶rt;uau uu n m nm ¶rt; ¶rt;. a uau ¶rt;m a ma m nau a¶rt;a, amu aa mu. au mu uu naam, m m¶rt;au n ¶rt;am ¶rt;mam m mam ¶rt;a u amu aa mu (. u. 9). aumu amu, uauau n ma nam ¶rt;a . ¶rt; amu m am ¶rt;m ¶rt;am mumm mam a naama am, an. aa uuau n, naama uauau n, um¶rt;.     

A note on secular variation of gravity due to non-tidal geodynamic phenomena

Summary Secular non-tidal variations of geopotential and gravity are estimated due to secular decrease of the second zonal geopotential harmonic, secular polar motion and deceleration of the Earth's rotation.

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am a nuu uunmuaa u u u mmu, a u m aauunmuaa, ¶rt;uu n u u mu au u.

     

Determination of tidal torques independently of densities

Summary The components of the tidal torques along the axes of the inertia ellipsoid of a perfectly elastic Earth have been derived quite independently of the density distribution of masses within the Earth. It has been demonstrated that not only the sectorial, but also the tesseral terms in the tidal forming potential are responsible for the tidal deceleration of the Earth's rotation.

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am ¶rt; mau ma nuu u m u a um unu¶rt;a uuu u¶rt;a n u, auu m ¶rt;a an¶rt;uu nmm a. aa, m nuu a¶rt;u au u a m muau, u mau nuuu au nuua nmua.

     

The gravitational effect of bodies with variable density

Summary Determination of the gravitational effect of some bodies, the density of which is supposed to be variable in the vertical direction, possibly in the horizontal direction, too.

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n¶rt;uaumau ma m m, nmm m um mua uu muma anau.

     

Moments of external disturbing forces in the rotational motion of celestial bodies

am ¶rt; mau mu ma uaumau u m a ma, ua aam ¶rt;uu ¶rt;a ma. a ma aamuam u¶rt;; n¶rt;aam u, m uaumau n nua mu nmu ¶rt; ¶rt;mam u mn, u m uma aua umuoa u nu u unu¶rt; uuu. u¶rt;um amo u, ¶rt;a ¶rt;a ¶rt;o 4- n¶rt;a um.     

Day-time ionospheric disturbances of corpuscular origin in the midlatitudeD-region

¶rt;m uu nau mu m a nu a¶rt;u ¶rt; D-amu u. a¶rt; m nu u u. u¶rt;a a a mu nma u nma mu m (20 ¶rt; 150 ).     

Spectral properties of clouds

Summary In the shortwave region the variations of the spectral properties of clouds are due only to the variations of optical characteristics of water. It results in small variations in the scattering pattern. In the longwave region scattering and absorption are of essentially diffraction character. Results of computation for a typical cloud drop are given; the accuracy of «the layer of precipitated water» method is analysed; thicknesses of cloud layers are investigated when the flux incoming into a cloud gradually deforms into the blackbody radiation flux.

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. , , .

     

Statistical analysis of values measured in condensating geodetic nets

Summary Procedure for verifying the agreement between parameters common to the basic and connecting trigonometric net. Procedure of determining the accuracy of the connecting net. This determination concerns not only the relativized accuracy of the points of the connecting network, but also the mutual accuracy of the points of the basic net relative to the points of the connecting net and the global accuracy of the resultant net. The procedure takes into account the accuracy of the points of the basic net which remain unchanged in computing the coordinates of new points.

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m¶rt; ¶rt; nu au u naam¶rt;mu u nu¶rt;u m. m¶rt; ¶rt; u mmu nu¶rt;u mu. a aam m mum nua mmu m nu¶rt; mu, ma au mmu m mu n mu ma nu¶rt;u mu ua mmu mu mu. m¶rt; umam mm m mu, m aa uu ¶rt;uam m mam uu.

     

The response of the total electron content to the interplanetary magnetic sector boundary crossing

¶rt;m uu n ¶rt;au m uu nu mau nam aum n. mu uu auam mmmuu uuu ¶rt;u u naam. a¶rt;am auu ¶rt; uuu n ¶rt;au m u u. a auu a¶rt;am nuu amm 245 . ¶rt;aam umnmau m a¶rt;a uu.     

On SEC disturbances in the polar cap ionosphere and their relation to the solar wind parameters

Summary Based on the analysis of the occurrence ofSEC disturbances in the polar cap ionosphere under varying solar wind parameters, the relation between the generation ofSEC-type ionospheric disturbances and interplanetary and magnetospheric conditions is discussed. It is emphasized that the Farley-Buneman instability in the E-layer of the ionosphere, reflected in ionograms as anSEC disturbance, depends on the complex effect of the solar wind parameters, the orientation of the interplanetary magnetic field playing an important role.

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a aaua nu u munaSEC n an u nu uu naama ma mam ¶rt; uu mu u, ¶rt; m, u namu u aumu uu, ¶rt;. ¶rt;uam, m maum au-aa, uaa u, u na a uaa a u munaSEC, auum m n uu naam ma, nu numau nam aum n uam aum .