On free nutation of the rotation vector of a rigid body

aam, m ¶rt;-mau ¶rt;uu a ma au am m¶rt; ma m unmuu m m. ¶rt;a, u a u unmuu annuuam, m am n una u 0,1 u a u ammuuu ¶rt;mau aa m m.     

Global geoidal undulations as inferred from the Bruns formula and from inversion of the geopotential series

Summary The problem of inverting the geopotential series with respect to the geoid radius has been solved. A linearization of the radius powers, making use of a reference surface, has been applied. The body given by the Bruns' formula has been chosen as the reference surface. Corrections to the Bruns' formula in an analytical explicit form have been derived. An internal linearization accuracy of the order of 1 mm has been achieved. The geoid radius coefficients for the GEM-L2 model have been evaluated numerically. The corrections have been found to range from –90 to 90 cm.

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m¶rt; uauauu ¶rt; aaumuu u ¶rt; ama a¶rt;ua — ma, m una uum au aumau n u u naam unu¶rt;a. u u¶rt; una um uum u nmuaa u uum au a¶rt;ua — ma. ¶rt;a¶rt;amua ua, aa uauau, n¶rt;a 1 . u¶rt; u am ¶rt; ¶rt;uaumau n GEM-L2. au na nm mm m am nu annuauuu¶rt;a, a a m a, n¶rt;a ± 90 .

     

Czech hydrometeorological institute limited-area operational forecast model

Summary The CHMI LAOFM is used in the daily routine of the Central Forecasting Office of the Czech Hydrometeorological Institute and some special results are transmitted to the regional offices. The model works in the region of Europe and the North Atlantic, uses conservative finite difference schemes and two types of semi-implicit schemes that allow effective model structurization in terms of programming language. The basic philosophy of the model is described.

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¶rt; a zau mumuu unm zumzu umumm () ¶rt; z uz nza. m mam ¶rt;a zu nzam am amuu. z amam amu n u amu mamuz aa, un am , a a aa au. ama aum mu auau z n- , ma cam m nm a auuam mmauau nza. mam nuaa u u auauu.

     

Palaeointensity of the geomagnetic field during upper cainozoic derived from palaeo-slags and porcellanites in north Bohemia

Summary Porcellanites and palaeo-slags from North Bohemia are natural materials which can be used to derive the palaeomagnetic directions and palaeointensity of the geomagnetic field active at the time of caustic alteration. The origin of these rocks, called erdbrands, was due to the caustic alteration of predominantly pelitic sediments as a result of underground fires conditioned by spontaneous ignition of coal seams. The caustic alteration occurred during the Upper Pliocene to the Quaternary. Three procedure based on the methods by Thellier and Nagata are presented in the paper. The newly developed apparatus MAVACS (Magnetic Vacuum Control System) was used for the thermal demagnetization of samples. A procedure based on multi-component analysis was also proposed and tested. Besides some methodic results, it was found that the geomagnetic field intensity varied during the respective period within the limits of 48%±4% to 154%±32% of the present geomagnetic field intensity.

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aum u na au a mumuu uu n¶rt;mam nu¶rt; amua, m n¶rt;¶rt;um ¶rt; ¶rt;u naaum anau u naumumuaum n, ¶rt;m amu uu. mu n¶rt;, aa ¶rt;a¶rt;, uu n¶rt; uu amu uu num num a¶rt; n¶rt; ¶rt;mu aau . amu uu u m nu¶rt; m nua ¶rt; mmu nu¶rt;a. am n¶rt; mu umnmau nua, n¶rt;¶rt;u ¶rt; ¶rt;u naumumu, nuau a m¶rt; u aama. a aamaa annaama MAVACS (Magnetic Vacuum Control System) a unaa ¶rt; mu aauuau ¶rt; amu aa. n¶rt; u n n¶rt;¶rt;, a a munm aau amuauu. nu m¶rt;uu au, ma ma, m umumaum n u¶rt; nu¶rt; a n¶rt;a 48%±4%-154%±32% au umumu aum n.

     

Characteristics of the mid-latitude ionosphere suitable for modelling ionospheric filtration of ULF waves

Summary An approximate method of one-dimensional modelling of the plasma of the Earth's ionosphere is demonstrated for purposes of studying the ionospheric filtration of ULF waves (micropulsations). Apart from the basic local parameters, characterizing the plasma, also derived local characteristics have been defined, i.e. the mass of the so-called effective ion and its effective collision frequency . Drawing on existing empirical models of the mid-latitude ionosphere, vertical profiles (50 km h 1000 km) were determined of the characteristics N_e N_i, v_e, and for the daytime and nighttime mid-latitude ionosphere under low and enhanced solar activity, which can be used to study the ionospheric ULF filter.

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aa nu uum m¶rt; ¶rt;a ¶rt;uau na ¶rt; u ¶rt; nmm uu u umauu (unau). ¶rt; u mu naamau na n¶rt; mu m aamumuu — aa m. a. mu ua, , u mua amma mu, . a mu nuuu ¶rt; ¶rt;um u u n¶rt; mua nuu (50 h 1000 ) aamumu N_e N_i, v_e, u ¶rt; u u ¶rt;u um nu u u amumu. ¶rt;u nam nu uuu u uma.

     

Analysis and optimization of wide-band force-balance seismometer responses

¶rt; aau n¶rt;am uu, umu,au mummu u ¶rt;uau ¶rt;uanaa mu um. am n a nmua amm aamumuu um ¶rt; au uu nuu. ¶rt;ma ummuu m¶rt; nmuau mu um a a¶rt;a an¶rt;u n n¶rt;am uu n nmu.     

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.

     

Long term variation in the secular love number

Summary It has been demonstrated that the observed decrease in the second zonal geopotential harmonic linear in time and the secular decrease in the angular velocity of the Earth's rotation do not satisfy the relation defining the secular Love number k as constant during the whole history of the Earth's evolution. The discrepancy disappears if it is assumed thatdk/dt=–2.4×10^–6 cy^–1 .

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aa, m a ¶rt;a au m aauunmuaa u u a ¶rt;a u mu au u ¶rt;mm mu, n¶rt; u a a nm mu umuu u. a uam, u ¶rt;nmumdk/dt=–2,4·10 ^–6 (mmu)^–1 .

     

High heat flow measured in Ostrava-Karviná coal basin

aamuam mam uu mn nma ma-au a. a¶rt; uua¶rt;uma mnam, uuma mnn¶rt;mu u mn nma m ¶rt;uamau au uu uma, n¶rt; m n¶rt; mn nm nu¶rt; a. 2. a u au Q=1,99 u 2,06×10^–6 /² am ¶rt;au mu n ua amu, ma mu (2,5×10^–6 a/² ) aum nam mm ¶rt;uana. um mm am na m¶rt;, ¶rt;¶rt; nu¶rt;m am mam.     

Velocities of seismic waves propagating through the Bohemian massif from foci in Poland

mam mm ua a na Pn, Pg, Sn u Sg nu¶rt;u u au -ma. aa, m ¶rt; amu 5° m numa ua¶rt;a ¶rt;am mu a na n au ma¶rt;amu u mu anmau , uu m n u ma¶rt;am¶rt;a. am nmau a uu m anmau mmu aua.     

On the structure of the interplanetary magnetic field under non-stationary boundary conditions

Summary The structure of the interplanetary magnetic field (IMF) is investigated theoretically in a kinematic approximation under frozen-in conditions in the solar wind and non-stationary boundary conditions. As an example, a time-dependent model of the IMF, created in the case of a change of the general magnetic field of the Sun represented by the dipole term, is analyzed. Very simple assumptions as to the field of velocities in the solar wind are made. The results show the formation of zero IMF points of two types(O, X). Points of theO-type are formed and move radially in the equatorial plane. They are surrounded by magnetic clouds with loops of lines of force. Points of theX-type are formed and move radially above the poles.

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muu u¶rt;aa mma nam aum n() uamu nuuuu nu uu mu m u mauaau uu. am nua ama ¶rt; , ua nu uuu aum n a, n¶rt;ma ¶rt;un , auu m u. mum n m m ¶rt;a nmu n¶rt;nu. mam naam aau m ¶rt; mun(O, X). uO-muna uam u ¶rt;um a¶rt;ua amua nmu. u aumu aau nmu u uu. uX-muna uam u ¶rt;um a¶rt;ua a¶rt; nau.

     

A three-dimensional numerical model of advection and diffusion of urban source pollutants

ama mam maum n¶rt; n¶rt;um ma u ¶rt;, ¶rt;u ¶rt;unu nu nu au muu u. ¶rt;aa ¶rt; aa a uu au mm ¶rt;uuu n m¶rt;a am. u ¶rt;a n¶rt;aam m ¶rt; muu m nau am u u a um anu u m umu au, m ¶rt;aa ¶rt; a nm n¶rt;um nmam an¶rt;u mauu nu .     

A3 ionospheric absorption measurements on 1539 kHz at Panská Ves

u¶rt;m mam uu u nu a¶rt;u m¶rt;3 (a na¶rt;u) a amm 1539 a amuu aa a nu¶rt; am 1978 — am 1981. u m nuau nu mma. a¶rt;am u¶rt;aa ma (a aumu) u a auau nu, u u aauu u an u u. numa u am au nu ¶rt; =60° na¶rt;am. au naa, m nu u um a a ¶rt;a ¶rt;m a nu¶rt;, nu a m n u nua nu mma am 1980.     

Is there any relation between the sun's motion and global seismic activity?

Summary The seismic energy released by global earthquake activity with time was correlated with F=||, where || is the absolute value of the change of the Sun's acceleration with time. For deep earthquakes and probability P=0.95, the coefficient of correlation was found to be around 0.4. For shallow earthquakes, the dependence was not proved.

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¶rt;a u uu (1900–1982.) ua ¶rt; F=||,¶rt; || am au uu u a. mu (h>60 ) u ¶rt; mmu =0.95 uum uu ¶rt;muam0.45. nm mu auum a n¶rt;m¶rt;a.

     

On one formulation of the frontal wave problem

u nu m¶rt;a a u ¶rt; u amu ¶rt; au amm u a m amuu ma. ¶rt; au mam ¶rt; nma a¶rt;au.     

Stresses and displacements due to a stationary point source of heat in an elastic halfspace

am amu ¶rt; ¶rt; mnu annu u u, a maua m umu mna n nnmam. a auu uu naa, m uau anu m anuu amua muna u am am u n ummamuu anu uu nmu nnmama. auum m¶rt;uauu ¶rt;mu ¶rt;mu mau anu, ammu: a) ¶rt;mu um numa amu umua mna; ) m uu uu nm aa u u u nu uuu aa nuu a nmu u; ) aau amuau anu ammuu aau, m m nm u¶rt; n u amumu um mu am.     

Flow of a homogeneous electric field round a non-conducting hemisphere perpendicular to the axis of symmetry

au ¶rt; nmuaa mu n, a¶rt;u a, ¶rt;a ¶rt;¶rt; maua mu n na n¶rt;a na umuu, nn¶rt;u m nmmu ma nu n. a¶rt;aa a u um ¶rt;uam. a u ¶rt;m um u au. u m amamu n¶rt;¶rt; u u nu¶rt;um au nmuaa u¶rt; ¶rt;a nu¶rt;u u a¶rt;a mu uumau A _2k u B _2k+1 , n¶rt;mau au uua uum u uuu nmn au ¶rt; u nma a¶rt;au.     

Determination of the geopotential scale factor from satellite altimetry

Summary The geopotential scale factor R ₀ =GM/W ₀ has been determined on the basis of satellite altimetry as R _{0=(6 363 672·5±0·3) m} and/or the geopotential value on the geoid W ₀ =(62 636 256·5±3) m ² s ^–2 . It has been stated that R ₀ and/or W ₀ is independent of the tidal distortion of surface W=W ₀ due to the zero frequency tide.

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¶rt;a nmu amumuu u ama amnmuaa R ₀ =GM/W ₀ =(6 363 672,5±0,3) m u/uu aunmuaa a nmuu¶rt;a W ₀ =(62 636 256,5±3) m² s^–2. m, m R ₀ u/uu W ₀ auum m nm amu a a nuu ¶rt;au nmu W=W ₀ .

     

Optimum processing of gravimetric observations affected by the drift in a one-stage net,and the analysis of the accuracy of the results

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.

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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.

     

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.