Deceleration in the Earth's rotation due to the Sun

Summary The estimate of the tidal long-term decrease in the angular velocity of the Earth's rotation due to the Sun is given as –(0.8±0.3)×10 ^–22 rad s ^–2. It was computed on the basis of the observed total long-term decrease in , of the observed tidal deceleration of the Moon and the observed decrease in the second-degree zonal Stokes geopotential harmonic term. Adopting the estimate given, the product of the Love number and the tidal phase lag angle due to the Sun (in degrees) comes out as 0.53±0.20.

---

am a z nuuu u z mu au u, az : –(0,8±0,3) 10 ^–22 a¶rt; ^–2 . ¶rt; ua n a¶rt;a u , n a¶rt;a nuu u ¶rt;z ¶rt;uu u n a¶rt;a u mz az znmuaz naama ma. u num n au, m nu¶rt;u ua a a z u ( za¶rt;a) a z nuua a (0,53±0,20).

     

Large-scale distribution of magnetic fields,green corona and prominences during an extended activity cycle

The interrelations of the latitudinal distribution of the coronal green emission maxima, maximal numbers and areas of prominences, magnetic fields, sunspots, and polar faculae in the 20th and 21st sunspot cycles have been investigated. It is again demonstrated how the behaviour of all studied data depends on their heliographic latitude. In the polar zone, well separated from the equatorial we observe following polarity magnetic fields transported only polewards, while the equatorial zone is occupied mostly by leading polarity fields, developed there, moving equatorwards, and crossing the equator to the other hemisphere with the new cycle during the minimum of sunspot activity.This magnetic field distribution is well emphasized by the places of maximal occurrence of prominences and by the distribution of coronal green emission maxima which also differ in dependence on latitude.The question of identifying the first and last evolutionary stages of an extended cycle of activity is discussed and the existence of a magnetic activity cycle lasting 15–17 years is suggested.     

Kinematics in the z = 2.81 Galaxy and the Evidence for Rotation

The existence of rotation signatures in damped Lyαabsorption systems represents a crucial test of the hypothesis that these features arise in disks of normal spiral galaxies. We apply the method for evaluating such signatures to the metal absorption lines in QSO 0528-250. In particular, the systemic redshift of the absorber is inferred from the recent detection of emission in the absorber by Möller and Warren. The kinematics of this absorber are particularly interesting because molecular hydrogen, the densest ISM component of the assumed foreground absorbing galaxy, is detected. Contrary to a recent claim, the method yields a satisfactory value for the assumed rotation velocity of the absorber.     

Parameters of the Earth's tri-axial level ellipsoid

Summary Four parameters defining the Earth's tri-axial ellipsoid (E) have been derived on the basis of the condition that the gravity potential on E be constant and equal to the actual geopotential value (W₀) on the geoid. The geocentric gravitational constant, the angular velocity of the Earth's rotation, the actual 2nd degree geopotential Stokes parameters and W₀ are taken to be the primary geodetic constants defining E and its (normal) gravity field.     

Core, Halo and Strahl Electrons in the Solar Wind

Electron velocity distribution functions (VDF) observed in the low speed solar wind flow are generally characterized by ‘core’ and ‘halo’ electrons. In the high speed solar wind, a third population of ‘strahl’ electrons is generally observed. New collisional models based on the solution of the Fokker-Planck equation can be used to determine the importance of the different electron populations as a function of the radial distance. Typical electron velocity distribution functions observed at 1 AU from the Sun are used as boundary conditions for the high speed solar wind and for the low speed solar wind. Taking into account the effects of external forces and Coulomb collisions with a background plasma, suprathermal tails are found to be present in the electron VDF at low altitudes in the corona when they exist at large radial distances. This revised version was published online in July 2006 with corrections to the Cover Date.     

Geotectonics,karst morphology,and environmental problems

Relationships among tectogenetic karst types, major morphologic units, and environmental consequences are discussed. The development of urban centers and in-dustrial sites within the Dinaric Karst area without taking into account the above-mentioned parameters, require additional measures. This is necessary in order to avoid the pollution of groundwaters and karst springs used for water development.According to field experience and results of investigations, which were recently published, a reliable geotectonic interpretation needed for distinguishing orogenic and epi-oro-genic (epi-platform) karst terranes has usually been missing in analyses of karst morphology. This is important because the karst morphological features different in origin and distribution can be found in both types, respectively.     

Differences between Mean Sea Levels for the Pacific,Atlantic and Indian Oceans From Topex/Poseidon Altimetry

Geopotential values W of the mean equipotential surfaces representing the mean ocean topography were computed on the basis of four years (1993 - 1996) TOPEX/POSEIDON altimeter data: W = 62 636 854.10m ² s ^–2 for the Pacific (P), W = 62 636 858.20m ² s ^–2 for the Atlantic (A), W = 62 636 856.28m ²s^–2 for the Indian (I) Oceans. The corresponding mean separations between the ocean levels were obtained as follows: A – P = – 42 cm, I– P = – 22 cm, I – A = 20 cm, the rms errors came out at about 0.3 cm. No sea surface topography model was used in the solution.     

Post-noon two-minute period pulsating aurora and their relationship to the dayside convection pattern

Poleward-moving auroral forms, as observed by meridian-scanning photometers, in the vicinity of the cusp region are generally assumed to be the optical signature of flux transfer events. Another class of quasi-continuous, short period (1–2 min) wave-like auroral emission has been identified, closely co-located with the convection reversal boundary in the post-noon sector, which is similar in appearance to such cusp aurora. It is suggested that these short period wave-like auroral emissions, the optical signature of boundary plasma sheet precipitation in the region 1 field-aligned current system, are associated with ULF magnetohydrodynamic wave activity, which is observed simultaneously by ground magnetometer stations. This association with ULF wave activity is strengthened by the observation of several harmonic frequencies in the pulsation spectrum, each an overtone of the fundamental standing wave resonance frequency.     

On the expanding earth hypothesis

Summary The hypothesis of an expanding Earth is discussed on the basis of lunar laser ranging It is provcd that the given data do not indicate a secular increase in the principal moment of the Earth's inertia which would have to occur if the Earth were really expanding.

---

¶rt;amunma au u mu u ammuu a¶rt;u u ¶rt;a n a auu . aam, m n mu ¶rt;a m umamu amaua ma uuu u, m ¶rt; nmmam auu, u n¶rt; u m.

     

Thermo-elastic deformations due to the annual temperature variation at the tidal station in Vyhne

Summary The thermo-elastic deformations due to the annual temperature variation are computed. The time variation of these deformations is compared with the variation of the slow deformations observed at the tidal station in Vyhne.

---

u mnu ¶rt;auu, a¶rt; auau mnam nmu a nnmama. ¶rt; mu ¶rt;au a ¶rt; ¶rt; ¶rt;au, u a nuu mauu ().

---

---

Dedicated to RNDr Jan Pícha, CSc on his 70th birthday