Papers in Meteorology and Geophysics
Online ISSN : 1880-6643
Print ISSN : 0031-126X
ISSN-L : 0031-126X
Volume 24 , Issue 3
Showing 1-3 articles out of 3 articles from the selected issue
  • Takashi Nitta, Jun-ichi Yamamoto
    1973 Volume 24 Issue 3 Pages 289-309
    Published: December 25, 1973
    Released: December 11, 2012
    JOURNALS FREE ACCESS
    Frequency of cyclogenesis of intermediate-scale disturbances is surveyed over the Far East. We take up the following two items as the definition of the intermediate-scale disturbance: (1) The characteristic wavelength lies between 1,000 km and 2,000 km. (2) At the initial stage of the formation, the disturbance does not couple with upper troughs and is mostly confined to the lower part of the troposphere. The disturbance is usually formed on an extended front. Five-year statistics for the period 1966-70 show that on the average the monthly frequency in the first half year is in excess of the total average number and that in the second half year is less than that (Fig.1). However, features of the frequency distribution vary conspicuously from year to year (Table 1). Regardless of the year-toyear variation, we may describe the gross features of spatial distribution of cyclogenesis as follows: (a) In winter, most of the spots distribute over the sea off the southern coast of the Japan islands, (b) As the year advances to spring and early summer, intermediatescale disturbances appear in the lower latitudes. The horizontal distribution of cyclogenesis in July makes a zone centering on the Baiu front. (c) In autumn, the place of frequent cyclogenesis shifts northward and the disturbance disappears from the southwest Pacific. (d) The birthplace of the cyclone moves down to the south in winter (Fig.2)'. Comparison of the distribution with the monthly mean 500 mb pattern suggests the close connection between the cyclogenesis of intermediate-scale disturbances and the general circulation of the atmosphere (Fig.3). In short, we may say that in a year when the mean pattern shows a zonal or flat flow, the number of cyclones generated increases and that in a year when the upper long wave trough anchors in the west of Japan, the number descreases and the cyclogenesis of the ordinary baroclinic wave becomes active.
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  • Kunie Katayama, Masako Momiyama
    1973 Volume 24 Issue 3 Pages 311-329
    Published: December 25, 1973
    Released: December 11, 2012
    JOURNALS FREE ACCESS
    The seasonal variation of mortality from cerebrovascular diseases (cerebral haemorrhage, thrombosis & embolism, and others) in Japan is observed geographically and bioclimatologically, and international comparisons are made in this paper. Findings are summarized as follows:
    1). Mortality generally curves up to a peak in winter. In summer, it declines for haemorrhage but slightly increases for thrombosis & embolism, probably due to high humidity in this season.
    2) This phenomenon appears more clearly in the central (warm)than in the northern (cold) and southern (subtropical) parts of the Japanese archipelago, suggestive of the limited adaptability to the meteorological environment of the old-aged affected by cerebrovascular diseases.
    3) The summer maximum of mortality from cerebral thrombosis & embolism is somewhat higher in the urban than in the rural districts, but there is little difference between Kanto (East) and Kansai (West) in this country.
    4) The death rate is generally going down for haemorrhage but up for thrombosis & embolism year by year. It is necessary to secure better heating in winter and better air conditioning (less humidity) in summer, especially for old people.
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  • Sei Takagi
    1973 Volume 24 Issue 3 Pages 331-356
    Published: December 25, 1973
    Released: December 11, 2012
    JOURNALS FREE ACCESS
    Earthquakes which occur between the Japanese north-eastern_coast and the Japan Trench are called Off Tokachi earthquakes. Theseearthquakes contain many problems for Plate Tectonics. This theory asserts that these earthquakes are produced by direct pressure to the Trench. But, the mechanisms of these earthquakes go against this theory. For example, Fig.1 gives the radiation pattern classified by the quadrant theory, but observations at Hachinohe, Yamagata,, Matsushiro, Niigata, Utsunomiya, Hamada and Abashiri go against this type. Fig.2 shows the radiation pattern of the same earthquake as in Fig.1, but classified by the conical theory. This conical pattern is far more excellent than the quadrant type of Fig.1. The belowright figure shows the underground structure for making this pattern. Similarly, Fig.3 shows the radiation pattern classified by the quadrant theory, but obervations at Aomori, Akita, Wazima, Sumoto, Okayama, Koochi, Shimizu, Amamiooshima and Okinawa go against this quadrant type. So, this pattern also is not quadrant type. Yet, Fig.4gives the radiation pattern of the same earthquake as in Fig.3, classified by the conical theory. This is far more excellent than the quadrant type in Fig.3. The below-right figure shows the underground structure for making this pattern. Also, Fig.5 is the radiation pattern classified by the quadrant theory, but observations at Takada, Matsushiro, Toyama, Kanazawa, Kyoto and Owase go against the quadrant type. So, this pattern also is not quadrant type. Fig.6shows the radiation pattern of the same earthquake as in Fig.5, but classified by the conical theory. This conical pattern is far more excellent than the quadrant type in Fig.5. The below-right figure shows the underground structure for making this pattern. These quadrant types are classified by Dr. Masaj i Ichikawa.
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