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.

     

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.

     

The effect of the velocity of the centre of a cyclone on the generation of microseisms

Summary The influence of the velocity of the movement of the centre of the cycloneV _c.c. on the rate of amplitudes' change A/t and periods' change T/t of storm microseisms is investigated. The dependence A/t=k V _c.c. and T/t=k ¹ V _c.c. is obtained. Unmovable depression (V _c.c. =0) does not stipulate the change of A/t and T/t.

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u V _c.c. A/t T/t . A/t=k V _c.c. T/t=¹ V _c.c. . (V _c.c. =0) A/t T/t.

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Presented as a scientific communication to the IASPEI Assembly in Madrid, Sept. 1969.     

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.

     

Magnetic interpretation of dyke anomalies using derivatives

The horizontal and vertical derivative profiles of magnetic anomalies of dykes show some interesting properties. The points of zero derivatives and the points where the derivatives are equal are conjugate point pairs. A method of interpretation of dyke anomalies is suggested, which utilizes the distances between these points.Notation F Magnetic anomaly in total intensity - Z Depth to top of the dyke - 2T Width of the dyke - Geological dip of the dyke - I Effective intensity of magnetisation in the plane of profile - Dip of effective magnetisation vector in the plane of profile - Strike angle of the dyke - i Magnetic dip - Q – - Q _f –+arctan (sin coti) - I _f      

Effects of the interplanetary magnetic field sector structure in the winter ionosphere

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.

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¶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.

     

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.     

Stratospheric ozone variability near the IMF sector boundary

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.

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¶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.

     

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.

     

A numerical study of the heat transfer through a fluid layer with recirculating flow between concentric and eccentric spheres

A numerical study has been made of the heat transfer through a fluid layer with recirculating flow. The outer fluid surface was assumed to be spherical, while the inner surface consisted of a sphere concentrically or eccentrically located with respect to the outer spherical surface. The recirculating flow was assumed to be driven by a gas flow creating stress on the fluid's outer surface so that creeping (low Reynolds number) flow developed in its interior. The present study solves the Stokes equation of motion and the convective diffusion equation in bispherical coordinates and presents the streamline and isotherm patterns.Nomenclature a _i inner sphere radius - a _d outer sphere radius - A ₁ defined by equation (5) - A ₂ defined by equation (6) - B ₁ defined by equation (7) - B ₂ defined by equation (8) - c dimensional factor for bispherical coordinates - C constant in equation (4) - d narrowest distance between the two eccentric spheres - E ² operator defined by equation (1) in spherical coordinates and by equation (21) in bispherical coordinates - G modified vorticity, defined in equation (22) - G ^* non-dimensional modified vorticity, defined in equation (28) - h metric coefficient of bispherical coordinate system, defined in equation (18) - k _w thermal conductivity of water - K ₁ defined by equation (9) - K ₂ defined by equation (10) - N _Re Reynolds number=2a _dU/gn - N _Pe,h Peclet number=2a _dU/ - n integer counter - q heat flux - r radius - r ^* non-dimensional radius=r/a _d - S surface area - t time - t ^* non-dimensional time=t/a _d ² - T temperature - T _o temperature at inner sphere surface - T _a temperature at outer sphere surface - T ^* non-dimensional temperature;=(T–T _o)/(T_a–T_o) - u velocity - u _r radial velocity in spherical coordinates - u angular velocity in spherical coordinates - u radial velocity in bispherical coordinates - u angular velocity in bispherical coordinates - U free stream velocity - u _r ^* =u _r/U - u ^* =u /U - u ^* =u /U - u ^* =u /U Greek symbols a ₁ small displacement - vorticity, defined in equation (17) - ^* non-dimensional vorticity, defined in equation (27) - radial bispherical coordinates - _o bispherical coordinate of inner sphere - _a bispherical coordinate of outer sphere - angular coordinate in spherical coordinates - thermal diffusivity - _w thermal diffusivity of water - kinematic viscosity - angular bispherical coordinate - spherical coordinate - streamfunction - non-dimensional streamfunction for spherical coordinates, = /(U a _d ² ) - ^* non-dimensional streamfunction for bispherical coordinates, defined in equation (26)     

Generalized thermoelastic longitudinal waves in unbounded medium

Summary In this paper the generalized thermoelastic longitudinal waves and the temperature field set up due to coupling of the displacement and the temperature fields, with heat wave travelling with certain finite velocity, in an unbounded medium are studied. The thermoelastic displacement potential and the temperature field at any point are obtained in terms of the surface integrals involving the potential, the temperature and their normal derivatives.Notation x _i the cartesian coordinate system,i=1,2,3 - n (u _i) the displacement vector - (/x _i) the del operator - _t /t the derivative with respect to time - T _o the temperature corresponding to the natural stat of zero stress and strain - T Absolute temperature - c _e the specific heat - , Lamé's constants - ₀ the density - coefficient of linear thermal expansion - K thermal conductivity coefficient - _kk u - ₀ the relaxation time     

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.     

Torsional vibration of non-homogeneous isotropic hollow thick cylinder

Summary Free vibration of a thick hollow cylinder of non-homogeneous elastic material having rigidity and density varying according to the laws: (i) =₀(₀+₀ z) and Q=Q₀(Q₀+₀ z) for finite and infinite length of the cylinder and (ii) ₁/r = and Q = ₁/r for finite length only are considered in this paper. Frequency equations are deduced and respective numerical solutions are obtained.     

Constraints to the three-dimensional non-hydrostatic density distribution in the earth

Summary The paper is concerned with the properties of a density distribution within the Earth. A system of density parameter constraints involving Stokes' coefficients of the gravity field and the parameters describing the Earth's figure is derived. A density model, whose parameters fit these constraints, accounts for the fine structure of the gravity field and Earth's figure. Additional condition imposed on the average spherical density model are derived; they guarantee that the average spherical model is compatible with the 3-D density model.

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aamuam ma an¶rt;u nmmu mu u. ¶rt;a uma u, auuau au naam nmm ¶rt;u; uma am m naamaumau n u naam nuau u u. mma ¶rt;, naam m ¶rt;mm mu auuau u, nm n¶rt;um uu umnmau m mmaumau n u u u. ¶rt; ma ¶rt;num u, aa¶rt;au a ¶rt; u ¶rt; nmmu, m nuam ¶rt;uu ¶rt; u ¶rt;u m nmm ¶rt;.

     

On global short-periodic synchronous oscillations of the atmosphere

Summary The existence of global synchronous atmospheric oscillations with the period of about 1.4 hour is indicated in terms of a simple theoretical model of the circumpolar circulation.

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u nu nm mmu ¶rt;u un uuu naa maua au am nu¶rt; 1,4 .

     

Uniform heat flow in a semi-infinite medium disturbed by a body of different thermal conductivity

Summary The approximate solution for the disturbance of a uniform heat flow in a homogeneous semi-infinite medium by an object of different thermal conductivity buried in it is generally used in the interpretation of heat flow anomalies on the ocean bottom. In order to know the accuracy of the approximate solution, a comparison between the approximate solution and the exact solution is given in the case of a very long horizontal cylinder in a semi-infinite medium. The computed results indicate that the two solutions agree to within 10% whend>1.3 and 0.5<<2, whered is ratio of the depth to the radiusR ₀ of the cylinder and is the factor of the contrast of the thermal conductivities between the medium and the body. As for the cases when 1 and 1, the same accuracy can be obtained only whend>2. A similar approach is also applied to the case of a spherical conductor in a semi-infinite medium by using a bispherical harmonic solution. The results of both the bipolar solution and the bispherical solution show that when 1 andd1, the vertical thermal gradient at the surface of the semi-infinite medium is always positive and tends to zero, but a negative vertical gradient may be obtained for the approximate solutions.     

Klasse Äquivalenter,in Meridianen äquidistanter Abbildungen

am u aa auu uau, anm n u¶rt;uaa. u n nu m na uu; ¶rt; a am u¶rt; am ¶rt;uua au nu ¶rt;a u m¶rt; am. mam u nam n¶rt;m nu n ¶rt;uam, u n n¶rt;m uu, u m [3]. m¶rt; nuam mm, ¶rt;u ¶rt; amauu , u umum a nu.     

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.

     

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.

     

Some laboratory model experiments on the mechanism of two-dimensional momentum transfer in the atmosphere

Summary Investigating the jetstream formation in the upper troposphere, it becomes evident that two-dimensional transfer processes are, to a high degree, responsible for the accumulation of kinetic energy and momentum in those upper tropospheric regions. To shed light on these processes a series of barotropic model experiments has been carried out using a special dynamic procedure for vortex generation. In a large, rotating, cylindrical vessel (filled with water, rotation rate ₀) three smaller cylinders have been fitted eccentrically. Their rotation relative to the vessel (rotation rate _i ,i=1, 2, 3) produces a sharply limited narrow region around each of them, where a nearly two-dimensional relative motion can be observed. Beyond this region — we call it friction zone — there is no motion. Now if we impose some perturbation on this steady mean flow (e.g. by setting _i = 0) the zonal current breaks down into a definite number of vortices which show a random distribution. The dynamic behaviour of these nearly two-dimensional vortices can then be studied.The main results are: I) After the sudden breakdown of the friction zones the most intensive eddies, which are cyclonic, drift more or less directly towards the centre to be organized there into a larger vortex. This development is strongly influenced by the -effect and the ratio = _i /₀, which controls the supply of rotational energy. II) If there exists a steady zonal basic current, the vortices will be more and more deformed when approaching and penetrating the zonal flow until they are wholly incorporated.