On the Probability of the Persistence of Weather in Tokyo

[摘要] In this paper we investigated the abnormally high or low values of the air temperature which are accompanied by those of the neighbouring sea surface temperature and further whether the sea surface temperature has the effect upon the neighbouring air temperature and vice versa. The investigation was made at the eastern coast of the Ôu and Hokkaidô. At first we compared the anomaly of the monthly mean of the sea surface temperature with that of the neighbouring air temperature. Then the rates of the coincidence of the sign, plus or minus of the two anomalies and the rates of the parallel cases in which the increase (decrease) of one anomaly is accompanied by the increase (decrease) of the another are 70-60% in each case. But the former is a little larger than the latter.Next, we investigated the effect of the sea surface temperature upon the neighbouring air temperature. We calculated the rates of the parallel cases and opposite cases in the two curves, the difference between the anomaly of the air temperature of the next month and that of this month and the difference between the anomaly of the sea surface temperature and that of the air temperature of this month. The same was done with respect to the case of the effect of the air temperature upon the sea surface temperature. From these we obtained the following results.(i) In the former case the rates of the parallel cases are 70-60% and in the latter case those are a little smaller.(ii) The effect of the sea surface temperature upon the air temperature is greater in the case of the local sea surface temperature than in the case of the mean sea surface temperature of a large region, and the effect of the air temperature upon the sea surface temperature is smaller in the former case than in the latter case.(iii) In the case of the local sea surface temperature at the places where the effect of the sea surface temperature upon the air temperature is great the effect of the air temperature upon the sea surface temperature is small.Further we proceeded to the investigation whether the parallel cases and opposit cases occur quite at random with the probability of the each occurrence respectively in the both cases of the effect of the sea surface temperature upon the air temperature and that of the air temperature upon the sea surface temperature. It results that in the former case the parallel cases and opposite cases occur nearly at random and in the latter case the both occurrences have the tendency to repeat a little.

[学科分类] 大气科学