There seems to exist a remarkable coast effect on typhoon movement. Sometimes hurricanes are seen to advance parrallel to the coast along Cape Hatteras. Similar, and more marked coast effect on typhoon movement can be seen along the coast of the Kwanto District (Greater Tokyo Area) in Japan. A simple dynamical explanation of this effect is offered.

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[in Japanese]

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The nature of variation of mean zonal wind for the 500-mb surface was investigated in two winters. The well-defined southerly trends of ΔU were frequently observed, and consequently they also influenced the cross correlation of ΔU between a particular latitude and the others. The periodicity of about 25-day was found in middle latitudes and it coincided with the mean period which was calculated from a dynamical theory of mean zonal wind.

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From rainguage records, showery rainfalls from convective clouds were picked out, and the from of the time-section pattern of the rain intensity was investigated. It was found by means of some normalization that the form is expressed by the formula,
I=Aτ^mexp(-nτ), I=A
where I denotes intensity of rain,τ, time and m and n are constants. This typical form maintains in the developing stage of the convection cells up to moderate. The elementary cells as shown by the formula. are usually supposed to be amalgamated into one cell when the convection has grown up so as to bring an extremely intense rain such as more than 10 mm per ten minutes.

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This paper describes a device that indicates rainfall contour lines on radar scopes. For this purpose a range correcting signal γ, a signal K₁γ correcting atmospheric gases attenuation, a signal K₂R^αdγ correcting for attenuation by intervening rain and predetermined B, β signals which show the raindrop characteristics, are compensated for the input signal Pγ which is reflected from the rainfall. After the resultant signals are selected by a predetermined level which corresponds to a certain rainfall, the selected signals are presented on the PPI or the Rill scope as rainfall contours.
It is convenient to use Pγ, γ and B in the logarithmic unit for the circuit construction and the rainfall measurements will range over 60dB.
A mechanism which carries out level selections is added to this device. As the mechanism is constructed so as to synchronize with the radar antenna rotation, the iso patterns are automatically photographed by a 35 mm camera. It is also possible to skip certain levels freely for effective photographing.
Comparisons between rain gages and this device show pretty good agreement, by correcting for the attenuation by intervening rain. But the attenuation will be one of the very important causes of the errors in case we use a 3.2 cm wavelength radar.

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The angular distribution o f the infrared sky radiation whose wavelength is 8000 Å in the turbid atmosphere with the various optical thicknesses corresponding to the variation of turbidity, was calculated on the basis of the primary scattering using an effective “ step-type ” size distribution of the aerosol particles. The calculations were performed for the angular distribution of the above-selected sky radiation in the vertical plane containing the sun and the zenith and for the scattering function. The results obtained are as follows:
The intensity of the sky radiation very near the sun i n the turbid atmosphere is very strong, in which region (whose angular distances from the sun are smaller 5°) the “ larger particles ” mainly contribute to the sky radiation, and in the near region (whose angular distances from the sun are roughly between 5° and 20°) the “ medium particles ”mainly contribute to it, while in the intermediate region (whose angular distances from the sun are roughly between 20° and 50° 90°, the lower limit depending on turbidity) the “ smaller particles ” mainly contribute to it, and in the far region (whose angular distances from the sun are larger than 50°) air molecules mainly contribute to it. The definitions of larger, medium and smaller particles are given below. The region in which air molecules mainly contribute to the sky radiation decrease with the increase of optical thickness corresponding to the increase of turbidity as expected. The scattering functions were also calculated for the various optical thicknesses (turbidities). The results show that as optical thickness (turbidity) becomes larger, the slope of the scattering function becomes steeper. Their agreement with the observed scattering fuctions obtained by ANTHONYis not bad. But in the intermediate region, the departures of calculated scattering functions from the observed one are large. This may principally result from the departure of the size distribution of the aerosol particles in ANTHONY'S results from the a^-3-law of size distribution of the aerosol particles in the mean state of turbid atmosphere.

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The cumulative amount of S r - 9 0 in Tokyo through the middle of 1958 reached 11.3 mc/km². The fall rate of Sr-90 has the positive correlation of +0.69 with the rainfall amount but it has no s p ring maximum as suggested by MACHTA et al. The estimated amoun t of fallout in the future will be about 50 mc/km² even if nuclear tests sto p now. The average age of fallout which is calculated from the ra t i o of Sr-89 and Sr-90 was from 200 to 300 days. The difference betw e e n the atmospheric ozone and the Sr-90 in the stratosphere is dis c u s s ed. It is concluded that the radioactive deposit on the earth is affected by locations and seasons of injection of Sr-90 into the stratosphere as well as the turbulent motion on a larger scale.

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The writer tried to obtain the same M as those given by the Pasadena seismological laboratory for the deep-focus earthquakes in and near Japan by using the seismological data obtained at Japanese stations.
And the writer succeeded in finding a method to get M with a difference of + 0.3 unit of magnitude as compared with the Pasadena determination.
It is shown that the calculated log A/T-Δ curves for deep earthquakes of various depths on the basis of Norman Ricker's wavelet theory fit well with the observed values.
It is shown that the magnitude of deep earthquakes can be given by the formula,
0.63M= log A₀/ T₀+α (H),
so far as the magnitude does not exceed 7.
If M exceeds 7, we must use the other formula,
{ 0.63 + 0.08 (log A₀/ T₀+α (H) -4.4) } M=log A₀/ T₀+α (H).
And α (H) is given by the formula
α (H) =2.5 T₀ - 2.8,
where to is the travel time of the S phase at the epicenter.
It is shown that the station corrections for dee p earthquakes are quite different from those for shallow earthquakes.
Some examples are shown to sugges t that there is the azimuthal factor among the observed log A/T, having some intimate connections with the mechanism of the occurrence of the earthquakes.
Some theoretical considerations are made o n the formula
log A₀/ T₀ =0.63M-α (H).

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Many aftershocks of the earthquake off Izu Peninsula were observed at the Matsushiro Seismological Observatory by two kinds of seismometers, the standard torsion seismometers and the short period vertical electromagnetic seismometer. Since no other seismological stations equipped with sensitive seismometers were available, the aftershocks have been investigated by the data obtained at Matsushiro alone.
First, the aftershocks are selected on the qualitative b a sis, and then in order to determine the magnitude of each shock a method to determine the magnitude by seismometer other than the standard seismometer is proposed on the theoretical and observational basis.
Lastly, some characteristics of the aftershock sequence are presented.

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The formation of Showa-Shinzan, the world-famous volcano in the history of volcanology, was accompanied by marked swarms of earthquakes. The author, aiming to study in detail the characteristics of these earthquakes recorded by the seismographs at three weather stations around Showa-Shinzan, namely, Sapporo (DMO) (Δ=69km), Mori (Δ=54km) and Muroran (LMO) (Δ=25km), as well as to obtain clues for predicting volcanic activities and further in order to clarify their mechanisms, has continued his research since he first reported on it in Part I of this paper. The principal results attained this time are summarized below:
1) The A-type earthquake swarms (December 1943-May 1944) which preceded the eruption had various amplitudes, but as the time of eruption drew near the amplitudes diminished exponentially. The B-type earthquake swarms accompanying the formation of the lava dome occurred when the eruption was over and lasted about one year, with nearly the same amplitudes throughout the period. This interesting fact suggests that there are some differences between the two types in hypocentral depth.
2) The waves of the maximum amplitudes are fairly distinctly polarized, and at all the three stations we observed that the ratio (AN/Ax) of the maximum amplitudes of the two components of horizontal motion is AN/AE>1 for the A-type earthquakes and, reversely, AN/AE<1 for the B-type earthquakes. This marked contrast between the two groups would be attributed largely to differences in the depths of hypocenters and the mechanism of occurrence of earthquakes.
3) During the early stage of the volcanic activity (December 28,1943-January 30,1944), the principal ten earthquakes of A-type distinctly showed the initial motions of P-waves. They appeared as compressional waves at Sapporo and Mori stations, and dilatational waves at Muroran station. Thus, a noteworthy result was obtained as compared with the migration of the hypocenters in the volcano.
4) There were recognized two phases which have str i k ingly slow group velocities. They were observed distinctly on the seismograph at Mori station (Δ=54 km). This tendency is particulary marked in the B-type earthquake swarms. The phases are tentatively named the third and the fourth phase. The velocity of the third phase appears to be less than 1 km/sec and that of fourth to be 340 m/sec. I t is safe to conclude from many evidences that the third is an Airy phase, whereas the fourth phase has characteristics of an Air-coupled Rayleigh wave.
5) The mode of variation of the amplitude ratio of the third and the fourth phase suggests the tendency of the hypocenters of the A type earthquakes to become shallower as the time of eruption draws near, while those of the B-type earthquakes deepen with the time elapsed after the eruption.

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[in Japanese]

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