Comment on the effect of a vorticity centre on a frontal boundary

Zusammenfassung Es wird der Einfluss des sogenannten Vorticity-Zentrums auf die Grenzfläche zweier Luftmassen der mittleren geographischen Breiten studiert. Zwecks Aufklärung der Rolle des Bewegungs- und Druckfeldes in diesem Prozesse wurde ein einfaches Modell konstruiert und numerisch gelöst. Die sich entwickelnde frontale Welle kann beziehungsweise als ein Anfangswert beim Lösen der mit der Stabilität der Wellen verbundenen Probleme mittels der Gleichungen, linearisiert durch die Methode der kleinen Störungen, dienen. Bei der Konstruktion des Modells wird ausser anderem von der Geometrie der Bewölkung ausgegangen, wie sie auf den Aufnahmen der meteorologischen Satelliten erfasst ist.     

Weighting of vertical angles

Summary According to the results of the adjustments of eight trigonometric and three-dimensional networks, the a priori variance m²() of the measured vertical angle is expressed by the formula: m²() = m²(a) + [C 1/2 m(k)]², where m(a) represents accidental observation errors; the constant C is estimated in the interval 0.5–1.5 according to the number of repreated observations and the variation of their changes with time; is the angle between the normals to the ellipsoid at the initial and final point of the line of sight, and m(k) is the mean square error of the coefficient of refraction which can be estimated for a given network from Tab. 1.Dedicated to 90th Birthday of Professor Frantiek Fiala     

Precision A.C. bridge set for measuring magnetic susceptibility of rocks and its anisotropy

Summary A bridge set for measuring the magnetic susceptibility of rocks and its anisotropy is described. The classical transformer bridge has been supplemented with an auxiliary compensating arm for balancing the bridge without any mechanical infringement of the measuring coils. By employing this principle and the appropriate methods a sensitivityof 4 × 10 ^–8 SI units (3 × 10 ^–9 e.m.u./cm³) has been achieved for a sample of 8 cm³ in volume. In addition to its high sensitivity the device has a considerable accuracy, which makes it suitable for susceptibility anisotropy measurements even of samples with a very low susceptibility and only slight anisotropy. Well-reproducible results have been achieved for samples with a mean susceptibility of the order of10 ^–5 SI units with an anisotropy degree of only about 1.05.Institute of Applied Geophysics.     

Über die Verteilung der aus Gezeitenbeobachtungen bestimmten gravimetrischen Faktoren in Europa

auamaumuu am, n u a¶rt;u nuu n ¶rt;a ₂, ₂, ₁ u ₁ (u. 1–4). na ¶rt;a ¶rt;am au ¶rt;um au an¶rt;u mu naam. a n¶rt;aam unam nu nuu nna m uu u u mmu mam ¶rt; uu u a a mau n.

---

---

Vorgetragen am 2. Internationalen Symposium Geodäsie und Physik der Erde, Potsdam, Mai 1973.     

Reduction of gravity observations with digital computer

Summary The paper gives a simple method for the reduction of Gravity observations with electronic computer. The major part of the gravity reductions is the computation of the correction for the far zones. This process was so simplified, that all far zone correction parameters depend on the topography can be determined — independent of the gravity measurement — for the whole survey area in one computer run (subprogram). The computed gravity data will be stored for plotter or other programs.

---

Zusammenfassung Die Arbeit gibt eine einfache Methode für die Reduktion gravimetrischer Meßdaten mit elektronischer Rechenmaschine. Den größten Teil der Reduktion von gravimetrischen Meßdaten machen die Korrektionen für die fernen Zonen aus. Diese Prozedur wurde so vereinfacht, daß man alle — von der Topographie abhängigen — Parameter der Fernzonenkorrektur, unabhängig von den gravimetrischen Me\daten, für das ganze Meßgebiet in einem Rechenprozeß berechnen kann. Die reduzierten gravimetrischen Meßdaten werden für Plotter oder andere Programme eingespeichert.

     

The Effect of Geomagnetic and Solar Activity on the Distribution of Controlling Pressure Formations in the Northern Hemisphere in Winter

The distribution of controlling pressure formations, occurring in the Northern Hemisphere during the winters (January and February) of the years 1952 – 1996, has been analysed. It was found that the deepening of the Icelandic and Aleutian pressure lows is connected not only with a particular QBO phase and level of geomagnetic activity (Bochníek et al., 1999) but also with a particular level of solar activity.     

Amplitude Response of a LCR Gravimeter with Feedback at Periods of Microseisms and Earthquake Waves

The amplitude response of a LCR gravimeter with the SRW-E feedback was determined on a vertical vibrating platform. The ink-pen recorder was connected parallel with the digital voltmeter input to obtain an analog response of the gravimeter to the harmonic motion of the base with a peak-to-peak amplitude of 10 m and periods excited in an interval of 4 - 10 s as by the ground motion of meteorological microseisms, and in the interval 10 -100 s as by surface waves of distant strong earthquakes. In the first interval, an unexpected maximum of the amplitude response was observed with the double amplitude of apparent 6,5 Gal (6.5 × 10 _–8 m/s ² ) at a period of 4.8 s, and a baseline shift with the amplitude of–64Gal was observed at the same period. The value of this direct component cannot be separated from the effect of the Earth's gravity field. In the second interval, the amplitude response of the gravimeter displayed one expected maximum at a period of 40 s with the double amplitude of 8.1Gal. At the usual level of microseisms with a peak-to-peak amplitude of up to 2 m the fluctuation of the gravimeter on the direct baseline shifted by –4.9 Gal was estimated at 1 Gal. With typical Rayleigh surface waves with periods of 20 s and double amplitudes of up to 100 m, the fluctuation reached 67 Gal.