Abstract
It is well known that cool summer in Hokkaido is brought by centering of the semipermanent high pressure in Okhotsk Sea. Recently the effect of Solar activity on the position of high pressure is a subject of interests of Far Eastern meteorologists. The author had formerly noticed the correlation between the summer Pacific and winter Continental highs. In the present note he has calculated the correlation coefficients between summer temperature at Sapporo, principal city of Hokkaido, and the barometric gradient over Hokkaido and its vicinity in the same month for 18 years from 1907 to 1924. He found correlations -0.51±0.12 for June, -0.71±0.08 for July, 0.48±0.13 for August. This shows that high pressure in Okhotsk Sea lowers air temperature in Hokkaido in the way that more north lies the high in Okhotsk more cool is the temperature in Hokkaido. He also noticed that: -
1. When the high pressure of Okhotsk Sea comes so south as 50° N and its western edge lies at or more west of 145° E meridian then it cools Hokkaido.
2. When the high comes so south as 45° or more, then it is a little warmer in Hokkaido. When the high lies at 40° N then it is warm in Hokkaido.
3. When the Pacific high lies to the south of Kurile Islands it is warm in Hokkaido.
4. Generally, Pacific and Okhotsk highs have a distance of about 20° between them.
5. The Pacific high begins to form in May and as the summer advances it shifts gradually towards north and disappears in November.
6. When the Pacific appears first near Hokkaido, it has tendency to keep the position. In such years extreme hot or cool summer is usually experienced. (June 1925)
