Various methods of statistical inference on the extreme values in geophysical phenomena have been proposed by many authors, but not many statistical procedures to treat errors attendant to such inference have yet been offered. In this pape r, the author proposes two simplified procedures to treat such problems statistically and applies these methods to meteorological data. Distrib u tion of the largest order statistic and stochastic extrapolation of truncated transformation curve for normalization are quite suggestive for such problems of inference and so technical modifications of these statistical methods were tried in their application to meteorological data.
The distinctions between shower and thunderstorm were made clear by analyses of radar data obtained at the Meteorological Research Institute in 1956 and 1958. The vertical velocities in thunderstorm were calculated from the echo height.
Similarity problems between prototype and model have been discussed hitherto by many authors, but one of the principal difficulties has seemed to be the lack of a consistent and adequate treatment of conditions for similarity. In the present paper, the relation U∞M/U∞N=(LM/LN)1/3, which has been theoretically obtained by considering not only the similarity of the mean flow patterns but also that of the turbulence structures, is proposed, for practical use, for the modeling criteria for a local wind under the conditions of neglecting molecular viscosity, Coriolis force and variation of hydrostatic pressure, and then the case in which a flow has thermal stratification is discussed.
A radar antenna model with a frame and a twin-rotor tail unit is experimented with regard to its rotational speed in the wind tunnel with the aim of improving its rotational characteristics. First the antenna dish alone is found rotatable in a wind once it is forced to rotate. The attachment of tail unit is very effective, increasing the rotational speed almost twice as large. Although the torque or power was not measured, a remarkable reduction in the antenna driving power can be expected for the same rotational speed. The attachment of the frame, which is designed to assist the rotation, is not promising due to its possible aerodynamic interference.
A new type of spectrophotometer is designed for the measurement of the angular distribution of sky radiation in a monochromatic range and also for that of spectral distribution of direct solar radiation. The principal parts of the instrument a the telescop e, a double monochrometer and a multiplier phototube. The opening angle of the telescope is about 54 ' and a special precaution is taken for removing stray light in the instrument and so the measurement of skylight as near as one degree from the sun is possible. Using this instrument we meas u red the spectral intensities of direct sunlight and those of the sun's aureole as far as 10 degrees with an interval of one degree for various altitudes of the sun. On the basis of the results of observation the spectral distribution of atmospheric extinction coefficient and the angular distribution of sky radiation were considered. As regards thespectral distribution of extinction coefficient observed curves showed two regions of different tendencies, namely a steep rising toward the shorter wave-length in the blue and ultra-violet region and a comparatively flat tendency in the yellow and red region. The anomalous transmission in the near ultra-violet which was discussed by DEIRMENDJIANa nd SEKERA (1956) could not be found according to this observation. One of the observed characteristics of the angular distribution of sky radiation is the tendency in the ultra-violet region at a very low sun elevation, where the sign of the gradient is reversed as compared with the other wave-lengths. This tendency was explained by calculation as the effect of multiple scattering. As to the effect of dust particl e s, a preliminary analysis was done using the results of calculations of DEIRMENDJIAN (1957) and those of BULLRICH (1952) concerning, respectively, the measurement of extinction coefficients and that of aureole. Marked deviation from the inverse fourth power law seems to exist concerning the size distribution of dust particles as far as the preliminary results are concerned.
The concentration of ozone and nitrogen dioxide in the surface air in Tokyo area was observed at two stations respectively in the suburb and the midtown. The results of ozone determination observed at the suburban station showed a seasonal variation with the maximum (29μg/m3) in April and the minimum (14μg/m3) in October. Day-to-day variation of ozone at the midtown area is closely correlated to that at the suburb and daily mean values in summer are higher at the former than the latter. This excess ozone was explained taking the seasonal variation of the air pollution into consideration. The ozone formation in the midtown area of Tokyo is quite probable. The concentration of nitrogen dioxide at the midtown area is about 2.5 times greater than that at the suburb and the maximum values were observed in winter season at both stations. In addition, the effects of SO2, NO2 and nitrate on the determination of ozone were examined. The results showed that SO2 is the most disturbing agent in the air of Tokyo.
Concentration of Cs-137 and Sr-90 in the western North Pacific was determined. The content of Cs-137 ranged from 0.8 μμC/l to 4.8 μμC/lwhile Sr-90 of 0.6 to 3.1 μμC/l was contained in sea water. These values are much higher than those obtained in the Atlantic and the eastern part of theNorth Pacific. The cause of higher contamination is the direct fiowout of the fission product from the proving grounds in the tropical region of the Pacific. The reason of the lower ratio of Cs-137/Sr-90 in sea water is also discussed.