Papers in Meteorology and Geophysics
Online ISSN : 1880-6643
Print ISSN : 0031-126X
ISSN-L : 0031-126X
Volume 20, Issue 3
Displaying 1-4 of 4 articles from this issue
  • On the Theory of Surface Cyclone Development
    Morio Takeuchi
    1969 Volume 20 Issue 3 Pages 207-251
    Published: December 25, 1969
    Released on J-STAGE: December 11, 2012
    In this paper is treated the theory of cyclones from a synoptic point of view. They also shall serves to understanding of the dynamical properties in the baroclinic models in numerical weather prediction.
    A model of baroclinic atmosphere adopted in the n umerical weather prediction is assumed.
    From the ω-equation in this baroclinic atmosphere the calculation formulae of the vertical current and horizontal divergence are derived by Fjørtoft's numerical integration method.
    According to these formulae, th e fitness of Sutcliffe's surface divergence formula is investigated.
    We derive the difference approximative formula of surface divergence shown by the weighted difference between the upper and the lower divergence both multiplied by respective constants, which is called weighted relative divergence in this paper.
    On the basis of these formulae, two theori e s of surface cyclone development are derived.
    The one theory describes the relations between the inclination of the axis of low pressure with heights and the development of cyclones.
    The other theory considers the problems concerning to the life history of cyclones, i. e. the formation, development and decay of cyclones.
    Download PDF (6350K)
  • Kiyoshi Kurashige
    1969 Volume 20 Issue 3 Pages 253-273
    Published: December 25, 1969
    Released on J-STAGE: December 11, 2012
    Numerical tables of the percent points in the F-distribution are calculated by an iterative numerical integration for fine levels. The calcluation is given by where a=1P is the percentage level, and (ni, n2) is the paired degrees of freedom. The computation is carried out for 295 values of re as is shown by a=100.0 (1.0)26.0,25.0 (0.5)10.5,10.0(0.1)1.1,1.00 (0.01)0.01%, Percentiles of the F (n1, n2) distribution are given roughly to 5significant figures by this calculation scheme for the case of the paired degrees of freedom, (3,3), (3,9), (9,9) and (1,9). However, in the case of (1,1) and (1,3), its values are given with less precision. On the latter cases, the accuracy of percentiles is attained up to 8significant figures at the lowest, by Newton-Raphson's method. The revised numerical tables of percent points of the F-distribution for the paired degrees of freedom (1,1), (1,3), (1,9), (3,3), (3,9) and (9,9) are supplemented in this paper.
    Download PDF (2840K)
  • Aftershock Areas and Intensity Distributions due to the Main Shocks
    Norio Yamakawa
    1969 Volume 20 Issue 3 Pages 275-286
    Published: December 25, 1969
    Released on J-STAGE: December 11, 2012
    First, it is emphasized that epicenters of large earthquakes are not the centers of source regions, but only starting points of large fractures called“earthquakes,”so that it is only natural that the relations between locations of epicenters of large earthquakes and the intensity distribution due to these earthquakes are very peculiar in some cases.
    Secondly, it is pointed out that the strong correlations can be seen between intensity distributions and aftershock areas as in the case of the Tonankai earthquake on 7 December 1944, because the latters can be considered as the fracturing areas due to the earthquakes concerned.
    Thirdly, in more detailed discussion, it is pointed out that aftershock area which show the strong correlations with intensity distributions are not the whole aftershock areas but the area of concentrated aftershock energy where only direct aftershocks in the present author's definition take places.
    Lastly, some related geophysical and seismological features are briefly discussed.
    Download PDF (1987K)
  • 1969 Volume 20 Issue 3 Pages 287-
    Published: 1969
    Released on J-STAGE: December 14, 2012