Papers in Meteorology and Geophysics
Online ISSN : 1880-6643
Print ISSN : 0031-126X
ISSN-L : 0031-126X
Volume 21, Issue 2
Displaying 1-6 of 6 articles from this issue
  • Iwao Tsuchiya
    1970 Volume 21 Issue 2 Pages 73-87
    Published: October 25, 1970
    Released on J-STAGE: December 11, 2012
    It is well known that year-to-year variations of rainfall are very peculiar over the so called equatorial Pacific dry zone which extends from the Peru coast to 180°or further west along the equator.
    As a result of investigating the world precipitation and precipitation anomaly distribution maps which are included in “Die Witterung in Ubersee (1953- )” by Hamburg Seewetteramt, the author recognized that there are very scanty rainfalls in the IndiaIndonesia region when there are anomalous plentiful rainfalls in the dry zone islands. These events occurred in 1957, 1958, 1965 and 1966. And in 1955, 1956 and 1962, reverse types are recognizable.
    Further investigations of the long-period Indian flood and drought data and the rainfall data of Ocean Island and Fanning Island in the dry zone have shown that the above mentioned reverse phase rainfall variations between India and the equatorial Pacific had occurred in earlier years.
    In addition to the relationships between these peculiar rainfall fluctuations and the influences of the southeast trades, we should. recognize the effect of mid-latitude westerlies in the Southern Hemisphere because anomalous rainfall distributions that occurred in 1957-58 and 1965-66, when the southern westerlies were very weak, especially in a winter month (July).
    Recently Walker's southern oscillation advanced to the new zonal and tropospheric circulation model in tropical and sub-tropical latitudes, which is named the Walker circulation by BJERKNES (1969). It is possible to say that the variations of southern westerlies play an important role in the weakening or strengthening of the Walker circulation through the variations of sea-surface temperature under the southeast trades.
    Download PDF (2323K)
  • Mixing Length Theory
    Akio Kurosaki
    1970 Volume 21 Issue 2 Pages 89-112
    Published: October 25, 1970
    Released on J-STAGE: December 11, 2012
    A form of mixing length was deduced so that in neutral conditions it would give von Karman's mixing length and, near the ground, match KEYPS law. The system of equations with the assumption of horizontal uniformity was solved both in stationary and in diurnal conditions. The considerations of energy equations indicated that we should solve the problem with the time derivative terms, and the results of time integrations explained some features of the diurnal changes of the planetary boundary layer.
    Download PDF (2626K)
  • Similarity Theory
    Akio Kurosaki
    1970 Volume 21 Issue 2 Pages 113-125
    Published: October 25, 1970
    Released on J-STAGE: December 11, 2012
    A similarity theory for th e planetary boundary layer was derived utilizing the complex expression for wind velocity. A diagram was made for the convenience of determining surface drag and wind rotation. Next, assuming that above the constant-flux layer eddy viscosity is independent of height, further formulae were gained. According to the analysis of data at O'Neill, some results at ideal conditions matched with the theory.
    Download PDF (1341K)
  • Its Geographical Differences in the United States
    Kunie Katayama, Masako Momiyama-Sakamoto
    1970 Volume 21 Issue 2 Pages 127-139
    Published: October 25, 1970
    Released on J-STAGE: December 11, 2012
    This paper presents a biometeorological study in the seasonal variation, by regions of the United States, of motality from both stroke (Int. List No.330-334, vascular lesions affecting the central nervous system) and heart diseases (Int. List No.410-443). We intend in this study to investigate into the chronological process of reduction in seasonal variation of mortality witnessed in recent years in the United States. The crude death rate varies fairly widely from region to region, depending upon the age composition of population, living conditions, and so forth in each state. Thus, the United States is divided into eight regions on the basis of geographical features, climate and socio-economic conditions related to these natural environments, and an attempt is made to find out the trends of mortality from stroke and heart diseases in the three decades,1930's (1930-34),1940and 1950. The following four types of seasonal variation in mortality are found:
    A) Nosummer peak is witnessed from the start in the mortality curve, bespeaking a fairly moderate seasonal variation. A decade later, mortality appears concentrated in winter, then the variation begins to reduce markedly. This trend is seen in the mortality curves for both diseases in three regions, namely the Pacific, Mountain and Great Lakes regions, and in the curve for heart diseases in Florida. Generally speaking, this trend is characteristic of the more prosperous areas of the United States.
    B) In the 1930's, a small peak exists in summer, then it gets flat with the result that seasonal variation becomes greater. But it has been steadily slowing down. This trend is seen for both diseases in the Great Plains South and the South regions and for stroke in Florida.
    C) No summer peak is seen from the start and seasonal variation is small, but it does not to indicate any sign of moderation, while the death rate rises along with the concentration of deaths in the cold season. This tendency is seen for both diseases in the Great Plains North region.
    D) The mortality curve rises markedly only in winter, and seasoonal variation gets more moderate in spite of the steady climb of the death rate. This is seen for both diseases in the highly industrialized Northeast region.
    It can thus been seen that the recent trends in the reduction of seasonal variation in mortality in the United States vary visibly, depending upon the geographical and socio-economic conditions. But steady progress has been made in each region, though in different degrees. In the northern part of the Great Plains North region which is the coldest area in the United States, be it noted, the seasoonal variation in infant mortality becomes markedly moderate, but this phenomenon is not apparent for stroke and heart diseases, indicating the importance of artificial climate for aged people.
    Download PDF (2115K)
  • Shozo Ito
    1970 Volume 21 Issue 2 Pages 141-241
    Published: October 25, 1970
    Released on J-STAGE: December 11, 2012
    Characteristics of turbulent diffusion in the atmospheric surface layer are theoretically treated, and the results are corroborated by experimental data in Parts I to V.
    The results are as follows: D e tailed discussion on the universal function is given in Parts I to IV. The theoretical relations of the stability to the turbulent heat flux and eddy diffusion coefficient are compared with the experimental ones. It is to be emphasized that the experimental data show good agreement with the theory.
    Relations between the standard deviation of smoke cloud and the down-wind distance are derived theoretically and are compared with the experimental data in wider range of stability. Detailed discussion is given in Part IV.
    Data obtained in the Project Green Glow are analysed by the numerical experiment in Part V. Taking the experimental site into account, the concentration patterns in the vertical direction are in good agreement with the experimetal data especially in the stratified flow.
    As discussed in Parts I to IV we have obtained good relations between the standard deviation of the smoke plume and the travel distance in the atmospheric surface layer. The conclusion, however, can't be decisive because it is not confirmed with respect to the turbulent-scale using observed facts. In Part VI and VII, the more detailed universal character of turbulence in the atmospheric surface layer is discussed using data obtained from two projects. One of them, nicknamed Futtu Project, was made in Japan by the Meteorological Research Institute. The other was the Great Plain Project in the U. S. A.
    First, micro-meteorological data are again analysed to determine the flux-gradient relationships for the transfer of momentum, sensible heat, as well as water vapor in the atmospheric surface layer in Part VI.
    The results obtained agree well with the universal relationships under the condition of z/L varying from 0 to -1 for the unstable and from 0 to 0.25 for the stable.
    In Part VII, a set of w ind, temperature and water vapor profile formulae is examined for the constant flux atmospheric surface layer. These formulae imply a relationship between eddy diffusivity and the stability parameter z/L.
    The derivation shows that the gradient Richardson number Ri is not equal to the z/L. Empirical evidence for the validity is obtained.
    A turbulent-scale, which is derived in this part, is related to the eddy diffusivities. The results show that the eddy diffusivities for momentum, sensible heat and water wapor can be expressed respectively by
    here, Li indicates the turbulent-scale in the vertical direction for wind, temperature and water vapor respectively with a subscript of u, θ, as well as w. ε is the dissipation rate of turbulent energy.
    Finally, the turbulent diffusion in the vertical direction is reexamined using the results obtained in Part VI, which can show the diffusion process by a simple rule; the ratio of vertical dispersion to the down-wind distance increases greatly with small wind shear and light mean wind speed, and decreases with large wind shear and strong mean wind speed in non-dimensional forms.
    It must, however, be noticed that the sim p le rule mentioned above applies only to open level country and makes no allowance for the possible disturbing effects of buildings and topographical features.
    Download PDF (9637K)
  • On the Eruption Tremor, Pre-eruption Earthquake and A-type Volcanic Earthquake
    Yasuhiro Tanaka
    1970 Volume 21 Issue 2 Pages 243-289
    Published: October 25, 1970
    Released on J-STAGE: December 11, 2012
    The main points of this paper are as follows:
    1) The origin and mechanism of the pre-erup tion earthquakes and eruption tremors are discussed.
    2) The relation between maximum amplitude and frequency distribution of isolated eruption tremors and A-type volcanic earthquakes are discussed.
    3) The pre-eruption earthquake have occurred at many former eruptions. The occurrence time of the pre-eruption earthquake and of the eruption are discussed.
    4) The origin of the A-type volcanic earthquakes and the relation between the swarm period of those earthquakes and the period of eruptions are discussed.
    5) The devi a tion of seismic ray at Izu-Oshima Island and the reason for it are discussed.
    Download PDF (7987K)