On the Bad Crops due to the Cool Summers in Northeastern Japan

Abstract

In Northeastern Japan, the production of agriculture, especially the crops of rice are much reduced frequently by the abnormal cool summers in the district, and many peoples living there are suffered very much from the shortage of the supply of foods. Since about 40 years up to the present, the investigations on the cause of the cool summers have been made by many meteorologists, oceanographers and agriculturists, and several hypothetical theories have been appeared such as “Theory of the prevailing of cold current Oyasiwo”, “Theory of the best formation of sea ice in northern sea”, “Theory of the prevailing of the general circulation of atmosphere and ocean”, “Theory of the large eruption of volcanoes”, “Theory related to the sunspot numbers” and “Theory of the path of typhoon in mid summer. In this report the author has explained of these theories briefly and proposed several methods for the researches on the causes of cool summers and the forecasting of them in the district.