By using the data of annunal rainfall in Korea for 153 years Mr. R. Sekiguchi investigated the Far Eastern seasonal correlation in connection with the solar activity (this Journal 37th year). Using the same data, the present author has investigated the correlation between the monthly amount of Korean rainfall and the solar activity. He calculated the range of average rainfall by the formula where m is the average rainfall, m1 and m2 its extreme values, M is the mean value, Δ is the absolute deviation of the amount of rainfall in each year from the mean value M, and n is the number of years taken in the statistics. The result is as follows: Then he classified the months into three classes of rich, moderate and poor precipitation. In rich months, as he understand, the amount of rainfall surpasses m1; in moderate months it lies between m1 and m2; in poor months it sinks under m2. By counting the number of months in each class, subclassified into three with respect to the sunspot number of the year, he obtained the following table. In the above table, the winter precipitation represents the sum of those for December, January and February, because the amount for each month is too small. For summer rainfall the amounts for July August and September are dealt with separately so that the frequency is 3 times as greater in summer than in winter. The general summer tendency is that in the year of small sunspot number there is remarkable tendency to_??_cause poor rainfall (27/20=135% ei 7/20 in favour) and in the year with moderate sunspot number there is tendency (10%) against poor precipitation and in favour of (8/62=13%) moderate precipitation. Rich precipitation is not so much affected by the sunspot number as moderate or poor rainfall. It occurs, however, preferably in years of great sunspot-number in the ratio of 21/18 or3/18=17% in favour. In winter the tendency becomes opposit. Small sunspot number rather corresponds to rich precipitation, moderate to moderate and great sunspot number to poor rainfall. In short, there is positive correlation of sunspot number with summer rainfall in Korea and negative one with winter precipitation. The author has also noticed that in some years of small sunspot number extremely heavy rainfall occurred in July. Taking statistics he has found that extremely rich rainfall and extremely poor rainfall during the summer three months occurred just in the same frequency as shown in the following table. The author then investigated the influence of the amplitude of the sunspot cycle on the Korean precipitation and found that in the greater sunspot cycle, the epoch of maximum and minimum rainfall shifts toward the year with greater sunspot number. He then investigated the sunspot correlation with the spring and autumn precipitation in Korea and found the gradual shift of the correlation from winter to summer type and again from summer to winter type. The author examined the correlation between the Korean summer rainfall and the summer temperature in Tohoku District in Japan. He has found that the sense of correlation has changed in 1910. Before that year, the correlation was negative and after that, the sense was positive. He then calculated the correlation between the summer temperature in Tohoku and summer precipitation of the preceeding year in Korea for years before 1910 and attained the positive high correlation. This must be a very significant result as to reveal the very important but curious phenomenon of the mutation of the sense of correlation or the rocking effect on correlation. (S. F.)
The author observed clouds with his new nephoscope for 450 days from February 1924 to June 1925. The observation for August of 1924 is missed. The frequency of cirrus drift in each ten degrees of azimuth during the whole period was shown in Fig. 1. (p. 317). The maximum frequency occurred in the interval of 260°-270° of Azimuth i. e. a little south of west, amounting 25.5% of the total frequency 278, of which 270 have west and 8 have east component of drift. The mean velocity for each month was shown in Fig. 2. (p. 317) which shows the remarkable contrast between summer and winter values. As well known, the velocity of travel of cyclonic centers in this vicinity is fast in winter and slow in summer. This fact may be explained to some degree from the upper air current and stands in concordance with the observation of Th. Hesselberg. The angles of deviation of the direction of the upper cloud drift from west was averaged for NW and SW quadrant for month to month. The result was shown in Fig. 3. (p. 318). The deviation was great in summer and less in winter, the average velocity of the cloud drift in various directions for four seasons is shown in Fig. 4. In winter the drift from between W and NW. is weaker than the drift from between W and SW. In summer there is no special preference between NW and SW.
By a simple experiment the author noticed that air current has tendency to flow round any object, i. e. the greater part of the current passes the object going round on its right and left side horizontally, only a small part goes over the object. He thinks therefore that winds must blow round any solitary mountain, so that föhn action in Hann's sence can not occur with such a mountain but it may take place only when the wind blows over a mountain range. He then tried to find an actual example, by comparing the wind observed at the mountain observatory of Tukubasan with the air current at the same height in the free air observed at the Aerological Observatory at Tateno, 19km distant from the mountain. He then find a regular deviation of wind direction at Tukubasan from that in the free air above Tateno. It seems as if to prove his idea, but he cannot draw any definite conclusion owing to the want of observation round the foot of the mountain.