The mathematical formu l ae of primary and secondary scattered light in the atmosphere including an absorption layer which was deduced by this author in the 3rd paper of this series are calculated numerically using an approximate method, replacing the integration of a continuous function by summation of a discontinuous step function. Thus are shown the influences caused by various types of absorption layers chiefly existing in the upper part of the atmosphere, on the primary and secondary scattered light, and also on the angular distribution. In every case of c alculation the major effect of the absorption layer is shown to decrease the secondary scattering. Curves of the vertical distribution of secondary emission are graphically shown in each case.
The results of the wind observation in the lower atmosphere made on a tower are described. This observation was made being connected with the cooperated observation of the tropospheric propagation of microwaves in Kanto district. The diurnal variations of the mean wind speeds with height were tabulated. The mean wind speed profiles follow the logarithmic law in the midday when the temperature lapse rate is adiabatic, but at night and in morning the wind speed profiles consist of two parts in each of which logarithmic law holds.
Atmospheric radio-refracti v e index is determined by the well-known formula based on DEBYE'S idea. This formula is used unaltered even in rainfall. However, judged from the fact that the electromagnetic scattering effect of waterdrops in rainfalls can be usually detected as radar-echoes, the existence of waterdrops must influence the radio-refractive index in the atmosphere. This problem is approached and discussed assuming Rayleigh scattering for a single drop and approximate mutual reactions among the scattered waves. It is concluded from the result obtained using the data on hydrometeors, that the influence upon the refractive index or the equivalent radiorefractive index could hardly be disregarded in certain cases.
Some investigations wer e made on the wave height and wave period of wind waves and swells, based on the data of. continuous observation of ocean waves with a self-registering wave gauge at Jogashima Island, Kanagawa Prefecture, Japan, duriug a year from September,1951 to August,1952, and the characteristics of variations of wave height and wave period and their relations to meteorological conditions were made clear. These results of analysis are also available for forecasting ocean waves. The variations of wave height and wave period can be classified into six types as shown schematically in Fig.5, and each of these types corresponds to a particular meteorological change. The points which have become known up to now are as follows: 1) In case a cyclone m oves eastward on the Pacific side of Honshu, Japan, the change of wave of “Type I” or“Type II” occurs at Jogashima Island, and the positions of the cyclonic centre at the time when the waves begin to become high, at the time when the wave height becomes maximum and at the time when the waves begin to decay at Jogashima Island are shown in Fig.8. Again, the positions of the cyclonic center at the time when the wave period becomes maximum are shown in Fig.9, Further, the maximum wave height, the duration of higher waves, etc. and their relations to the intensity and distance of the cyclone are shown in Figs.10-12. 2) In case a cyclone moves eastward on the. tapan Sea side of Honshu, the change of waves of “ Type III ” or “Type IV” occurs at Jogashima Island, and the maximum wave height, the duration of higher waves, -etc. in thaC. ca'se, are shown in Figs.,16-19. 3) In case a migratory anticyclone covers Honshu, the change of waves of “Type V” or “Type VI” occurs at Jogashima Island. And Fig.23 shows the extent of area covered by this migratory anticyclone when the sea is calm at Jogashima Island. 4) I n case the station under consideration is within the sphere of influence of Ogasawara Anticyclone, the change of waves is complicated, depending upon the nature of the sphere of influence. In this case, the change of waves of “Type V”or “Type VI” generally occurs, with incidental occurrence of the change of “Type III”. And we can see from Fig.25 the extent of area under the influence of this anticyclone when the sea is calm at Jogashima Island.
Peculiar tsunami waves p roduced by the eruption of a submarine volcano at Myojinsho Reef on March 11,1953 were recorded by wave gauges installed on Hachijojima Island, Cape Ornaezaki and Jogashima Island, which are distant from the volcano by 130,336 and 356 km, respectively. Moreover, from the 11th to the 25th of March tsunami waves were recorded about fifty times at Hachijojima Island. From these data we could make clear the features of the variation of waves with distance as well as with time, and it was proved that the theory of Cauchy-Poisson wave explains these waves satisfactorily. It was also shown that these waves were caused by an initial impulse rather than by an initial elevation at the moment of explosion, and that the waves progressed with group velocjty. In order to understand two kinds of tsunami waves, one of which shows a conspicuous beat phenomenon while the other does not, discussions were made on the effect of initial impulse of different types.