Weather forecast is generally regarded as social information containing a certain kind of uncertainty, and so information theory must be very effective for the verification of forecast technique and forecasted result. The author tried to introduce the idea of entropy in information theory to the various problems of weather forecast, and could show that the several verification measures hitherto known were systematically identified to the ideas of relative entropy or transmitted amount of information in information theory. Moreover, as a by-product o f such induction process, a simplified method to estimate correlation coefficient could be offered, and an effective procedure to issue weather forecast under several restricting conditions was gained by the principle of maximum total entropies. Lastly, the hypothetical examples of such procedure and actual situations were schematically shown for the daily temperature forecasting etc.
Radar and synoptic analyses were done on the storm that occurred around the stationary front, Baiu front. Many various echo patterns that appeared were compared with the synoptic situations. Then a weather system around the wave crest of small scale was represented, in which two squall lines and quasi-stationary and perfectly stationary rainbands were involved. On the rainbands, some detailed explanations are given.
A buried-type snowgage is introduced which measures and records the amount of snow-cover in the natural state as snow lies on the ground. A pit is dug with 4 m diameter and with 30 cm depth and a loop-type strain-meter is installed on a foundation at its center. Foundations are also made along the circumference, and beams are put circularly and radially between these foundations and from them to the strain-meter at the center. The beams support plates on them, on which soil coverage is spread until its surface is level with the surrounding ground. The strain at the center, which is equal to 1/3of the weight of snow-cover on the circle, is magnified and transferred with links to a recorder 4 m apart from the center. From the fact that the result of the test measurement made at Hokkaido University campus agrees very well with that of the simultaneous observations with a snow-sampler, the gage seems quite satisfactory for practical use for the measurement of snow-cover.
The start and stop characteristics of a pendulum anemometer devised by the Swiss meteorologist H. WILD are experimented in wind tunnel and free air. The anemometer is at present in use for the routine meteorological observation in the People's Republic of China, being simple and robust in spite of some shortcomings discussed in the present paper.
Field-changes due to lightn i ng flashes to ground recorded by an electrostatic fluxmeter have been investigated to obtain information on the charge distribution in the cloud. The negatively charged column of MALANa nd SCHONLANDis found to be applicable to intense thunderstorms in Japan. The analysis o f the stroke intervals of flashes of many strokes (10or more stokes) leads to the conclusion that, though the charge is distributed in the column non-uniformly as several or scores of concentrations associated with small unit cells (about 300 meters diameter), the general density of the negative charge along the column is higher in its base, becoming gradually lower toward its top. Two or three small concentrations of negative charge are usually necessary to produce each stroke subsequent to the first. However, in the case of very active storms, it occasionally happens that a stroke is produced by a single small concentration of negative charge.
In the preceding paper we investigated the effect of the ozone absorption layer on the distribution of the ultraviolet sky radiation, which was assumed as the primary scattered light only. According to the result, the existence of the effect of the absorption layer on the distribution of sky radiation was apparently recognized, but agreement between theory and observation was not enough to explain the phenomenon. To improve the agreement we have calculated the secondary scattered light also, and added it to the primary. By this, the discrepancy has been very much reduced.
The albedo of a Rayleigh atmosphere was calculated using Chandrasekhar's theory on the scattered light (1950) and the solar energy spectrum outside the earth's atmosphere obtained by F. S. JOHNSON (1954). The albedos of a Rayleigh atmosphere in several solar spectral regions, i. e. the ultraviolet-(λ ≤ 4000 Å), Visible(4000 Å < λ ≤7500Å ), infrared(λ > 7500 Å) and total wave length-regions, and their latitudinal variations at the equinox and at the summer (winter)solstice was calculated. The main results obtained are as follows: The calculated albedos of a Rayleigh atmosphere of the earth as a whole are 6.6% in case without clouds and 5.4% in case with, a mean amount of clouds and they are respectively smaller than the corresponding values obtained by S. FRITZ based on the observed values, i. e.8%(without clouds) and 6.4% (with a mean amount of clouds). At the equinox, the albedos in the above several -spectral regions in every latitude have the minima at the equator, increasing with latitude, and their latitudinal variations are similar in both hemispheres. At the summer (winter) solstice, they have the minima at about 23 degrees of the north (south) latitude but their latitudinal variations in the northern (southern) hemisphere are smaller than at the equinox; but in the southern (northern) hemisphere, they are larger than at the equinox. Seeing them in the above spectral regions respectively, the shorter the wave length, the larger is the latitudinal variation, but in the ultraviolet region it is not so large as we expect, since there is a strong absorption by oxygen and ozone in that region. The same features hold in both cases without clouds and with a mean amount of clouds.